Sample records for scale relative permeabilities

  1. Dynamic up-scaling of relative permeability in chalk

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    Frykman, P.; Lindgaard, H.F.


    This paper describes how fine-scale geo-statistic reservoir models can be utilised for the up-scaling of two-phase flow properties, including both relative permeability and capillary pressure function. The procedure is applied to a North Sea chalk carbonate reservoir example, which is a high-porosity/low-permeability reservoir type. The study focuses on waterflooding as the main recovery scheme and for the given flow regime in the reservoir. The main purpose of the paper is to demonstrate the use of dynamic multi-step up-scaling methods in the preparation of detailed geological information for full field reservoir simulation studies. (au) EFP-96. 39 refs.

  2. Calculation of large scale relative permeabilities from stochastic properties of the permeability field and fluid properties

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    Lenormand, R.; Thiele, M.R. [Institut Francais du Petrole, Rueil Malmaison (France)


    The paper describes the method and presents preliminary results for the calculation of homogenized relative permeabilities using stochastic properties of the permeability field. In heterogeneous media, the spreading of an injected fluid is mainly sue to the permeability heterogeneity and viscosity fingering. At large scale, when the heterogeneous medium is replaced by a homogeneous one, we need to introduce a homogenized (or pseudo) relative permeability to obtain the same spreading. Generally, is derived by using fine-grid numerical simulations (Kyte and Berry). However, this operation is time consuming and cannot be performed for all the meshes of the reservoir. We propose an alternate method which uses the information given by the stochastic properties of the field without any numerical simulation. The method is based on recent developments on homogenized transport equations (the {open_quotes}MHD{close_quotes} equation, Lenormand SPE 30797). The MHD equation accounts for the three basic mechanisms of spreading of the injected fluid: (1) Dispersive spreading due to small scale randomness, characterized by a macrodispersion coefficient D. (2) Convective spreading due to large scale heterogeneities (layers) characterized by a heterogeneity factor H. (3) Viscous fingering characterized by an apparent viscosity ration M. In the paper, we first derive the parameters D and H as functions of variance and correlation length of the permeability field. The results are shown to be in good agreement with fine-grid simulations. The are then derived a function of D, H and M. The main result is that this approach lead to a time dependent . Finally, the calculated are compared to the values derived by history matching using fine-grid numerical simulations.


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    Laura J. Pyrak-Nolte; Nicholas J. Giordano; David D. Nolte


    The principal challenge of upscaling techniques for multi-phase fluid dynamics in porous media is to determine which properties on the micro-scale can be used to predict macroscopic flow and spatial distribution of phases at core- and field-scales. The most notable outcome of recent theories is the identification of interfacial areas per volume for multiple phases as a fundamental parameter that determines much of the multi-phase properties of the porous medium. A formal program of experimental research was begun to directly test upscaling theories in fluid flow through porous media by comparing measurements of relative permeability and capillary-saturation with measurements of interfacial area per volume. This project on the experimental investigation of relative permeability upscaling has produced a unique combination of three quite different technical approaches to the upscaling problem of obtaining pore-related microscopic properties and using them to predict macroscopic behavior. Several important ''firsts'' have been achieved during the course of the project. (1) Optical coherence imaging, a laser-based ranging and imaging technique, has produced the first images of grain and pore structure up to 1 mm beneath the surface of the sandstone and in a laboratory borehole. (2) Woods metal injection has connected for the first time microscopic pore-scale geometric measurements with macroscopic saturation in real sandstone cores. (3) The micro-model technique has produced the first invertible relationship between saturation and capillary pressure--showing that interfacial area per volume (IAV) provides the linking parameter. IAV is a key element in upscaling theories, so this experimental finding may represent the most important result of this project, with wide ramifications for predictions of fluid behavior in porous media.

  4. Laboratory-scale measurements of effective relative permeability for layered sands

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    Butts, M.G.; Korsgaard, S.


    Predictions of the impact of remediation or the extent of contamination resulting from spills of gasoline, solvents and other petroleum products, must often be made in complex geological environments. Such problems can be treated by introducing the concept of effective parameters that incorporate the effects of soil layering or other heterogeneities into a large-scale flow description. Studies that derive effective multiphase parameters are few, and approximations are required to treat the non-linear multiphase flow equations. The purpose of this study is to measure effective relative permeabilities for well-defined multi-layered soils at the laboratory scale. Relative permeabilities were determined for homogeneous and layered, unconsolidated sands using the method of Jones and Roszelle (1978). The experimental data show that endpoint relative permeabilities are important in defining the shape of the relative permeability curves, but these cannot be predicted by estimation methods base on capillary pressure data. The most significant feature of the measured effective relative permeability curves is that the entrapped (residual) oil saturation is significantly larger than the residual saturation of the individual layers. This observation agrees with previous theoretical predictions of large-scale entrapment Butts, 1993 and (1995). Enhanced entrapment in heterogeneous soils has several important implications for spill remediation, for example, the reduced efficiency of direct recovery. (au) 17 refs.


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    JiangTao Cheng; Ping Yu; William Headley; Nicholas Giordao; Mirela Mustata; Daiquan Chen; Nathan Cooper; David D. Nolte; Laura J. Pyrak-Nolte


    The principal challenge of upscaling techniques for multi-phase fluid dynamics in porous media is to determine which properties on the micro-scale can be used to predict macroscopic flow and spatial distribution of phases at core- and field-scales. The most notable outcome of recent theories is the identification of interfacial areas per volume for multiple phases as a fundamental parameter that determines much of the multi-phase properties of the porous medium. A formal program of experimental research was begun to directly test upscaling theories in fluid flow through porous media by comparing measurements of relative permeability and capillary-saturation with measurements of interfacial area per volume. During this reporting period, we have shown experimentally and theoretically that the optical coherence imaging system is optimized for sandstone. The measurement of interfacial area per volume (IAV), capillary pressure and saturation in two dimensional micro-models structures that are statistically similar to real porous media has shown the existence of a unique relationship among these hydraulic parameters. The measurement of interfacial area per volume on a three-dimensional natural sample, i.e., sandstone, has the same length-scale as the values of IAV determined for the two-dimensional micro-models.


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    Laura J. Pyrak-Nolte; Ping Yu; JiangTao Cheng; Daiquan Chen; Nicholas Giordano; Mirela Mustata; John Coy; Nathan Cooper; David D. Nolte


    The principal challenge of upscaling techniques for multi-phase fluid dynamics in porous media is to determine which properties on the micro-scale can be used to predict macroscopic flow and spatial distribution of phases at core- and field-scales. The most notable outcome of recent theories is the identification of interfacial areas per volume for multiple phases as a fundamental parameter that determines much of the multi-phase properties of the porous medium. A formal program of experimental research was begun to directly test upscaling theories in fluid flow through porous media by comparing measurements of relative permeability and capillary-saturation with measurements of interfacial area per volume. During this reporting period, we have shown experimentally that the coherence detection can be performed in a borescope. The measurement of interfacial area per volume (IAV), capillary pressure and saturation in two dimensional micro-models structures has shown the existence of a unique relationship among these hydraulic parameters for different pore geometry. The measurement of interfacial area per volume on a three-dimensional natural sample, i.e., sandstone, is essentially completed for imbibition conditions.

  7. Characterizing two-phase flow relative permeabilities in chemicalflooding using a pore-scale network model

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    Liu, Qingjie; Shen, Pingping; Wu, Yu-Shu


    A dynamic pore-scale network model is presented for investigating the effects of interfacial tension and oil-water viscosity on relative permeability during chemical flooding. This model takes into account both viscous and capillary forces in analyzing the impact of chemical properties on flow behavior or displacement configuration, as opposed to the conventional or invasion percolation algorithm which incorporates capillary pressure only. The study results indicate that both water and oil relative-permeability curves are dependent strongly on interfacial tension as well as an oil-water viscosity ratio. In particular, water and oil relative-permeability curves are both found to shift upward as interfacial tension is reduced, and they both tend to become linear versus saturation once interfacial tension is at low values. In addition, the oil-water viscosity ratio appears to have only a small effect under conditions of high interfacial tension. When the interfacial tension is low, however, water relative permeability decreases more rapidly (with the increase in the aqueous-phase viscosity) than oil relative permeability. The breakthrough saturation of the aqueous phase during chemical flooding tends to decrease with the reduction of interfacial tension and may also be affected by the oil-water viscosity ratio.

  8. Experimental Investigation of Relative Permeability Upscaling from the Micro-Scale to the Macro-Scale

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    Nolte-Pyrak, Laura J.; Yu, Ping; Cheng, Jiangtao; Giordano, Nicholas


    During this reporting period, work was performed to initial test the laboratory equipment that will be used for testing the upscaling theories and to provide initial data sets. The holographic laser imaging technique (Optical Coherence Imaging) underwent initial testing and provided initial results (on imaging through turbid media, three-dimensional laser ranging and imaging sandstone), which lead to modifications to the system. Initial testing of the relative permeability system for the laboratory micro-models was performed and provided initial results on drainage & imbibition experiments. Initial testing of the Wood's metal injection system and permeability measurement system was performed on sandstone cores and modification to the system were made.

  9. Relative permeability through fractures

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    Diomampo, Gracel, P.


    The mechanism of two-phase flow through fractures is of importance in understanding many geologic processes. Currently, two-phase flow through fractures is still poorly understood. In this study, nitrogen-water experiments were done on both smooth and rough parallel plates to determine the governing flow mechanism for fractures and the appropriate methodology for data analysis. The experiments were done using a glass plate to allow visualization of flow. Digital video recording allowed instantaneous measurement of pressure, flow rate and saturation. Saturation was computed using image analysis techniques. The experiments showed that gas and liquid phases flow through fractures in nonuniform separate channels. The localized channels change with time as each phase path undergoes continues breaking and reforming due to invasion of the other phase. The stability of the phase paths is dependent on liquid and gas flow rate ratio. This mechanism holds true for over a range of saturation for both smooth and rough fractures. In imbibition for rough-walled fractures, another mechanism similar to wave-like flow in pipes was also observed. The data from the experiments were analyzed using Darcy's law and using the concept of friction factor and equivalent Reynold's number for two-phase flow. For both smooth- and rough-walled fractures a clear relationship between relative permeability and saturation was seen. The calculated relative permeability curves follow Corey-type behavior and can be modeled using Honarpour expressions. The sum of the relative permeabilities is not equal one, indicating phase interference. The equivalent homogeneous single-phase approach did not give satisfactory representation of flow through fractures. The graphs of experimentally derived friction factor with the modified Reynolds number do not reveal a distinctive linear relationship.

  10. Estimating regional-scale permeability-depth relations in a fractured-rock terrain using groundwater-flow model calibration (United States)

    Sanford, Ward E.


    The trend of decreasing permeability with depth was estimated in the fractured-rock terrain of the upper Potomac River basin in the eastern USA using model calibration on 200 water-level observations in wells and 12 base-flow observations in subwatersheds. Results indicate that permeability at the 1-10 km scale (for groundwater flowpaths) decreases by several orders of magnitude within the top 100 m of land surface. This depth range represents the transition from the weathered, fractured regolith into unweathered bedrock. This rate of decline is substantially greater than has been observed by previous investigators that have plotted in situ wellbore measurements versus depth. The difference is that regional water levels give information on kilometer-scale connectivity of the regolith and adjacent fracture networks, whereas in situ measurements give information on near-hole fractures and fracture networks. The approach taken was to calibrate model layer-to-layer ratios of hydraulic conductivity (LLKs) for each major rock type. Most rock types gave optimal LLK values of 40-60, where each layer was twice a thick as the one overlying it. Previous estimates of permeability with depth from deeper data showed less of a decline at water-level observations were available. The results have implications for improved understanding of watershed-scale groundwater flow and transport, such as for the timing of the migration of pollutants from the water table to streams.

  11. Steam-water relative permeability

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    Ambusso, W.; Satik, C.; Home, R.N. [Stanford Univ., CA (United States)


    A set of relative permeability relations for simultaneous flow of steam and water in porous media have been measured in steady state experiments conducted under the conditions that eliminate most errors associated with saturation and pressure measurements. These relations show that the relative permeabilities for steam-water flow in porous media vary approximately linearly with saturation. This departure from the nitrogen/water behavior indicates that there are fundamental differences between steam/water and nitrogen/water flows. The saturations in these experiments were measured by using a high resolution X-ray computer tomography (CT) scanner. In addition the pressure gradients were obtained from the measurements of liquid phase pressure over the portions with flat saturation profiles. These two aspects constitute a major improvement in the experimental method compared to those used in the past. Comparison of the saturation profiles measured by the X-ray CT scanner during the experiments shows a good agreement with those predicted by numerical simulations. To obtain results that are applicable to general flow of steam and water in porous media similar experiments will be conducted at higher temperature and with porous rocks of different wetting characteristics and porosity distribution.

  12. Two scale analysis applied to low permeability sandstones (United States)

    Davy, Catherine; Song, Yang; Nguyen Kim, Thang; Adler, Pierre


    Low permeability materials are often composed of several pore structures of various scales, which are superposed one to another. It is often impossible to measure and to determine the macroscopic properties in one step. In the low permeability sandstones that we consider, the pore space is essentially made of micro-cracks between grains. These fissures are two dimensional structures, which aperture is roughly on the order of one micron. On the grain scale, i.e., on the scale of 1 mm, the fissures form a network. These two structures can be measured by using two different tools [1]. The density of the fissure networks is estimated by trace measurements on the two dimensional images provided by classical 2D Scanning Electron Microscopy (SEM) with a pixel size of 2.2 micron. The three dimensional geometry of the fissures is measured by X-Ray micro-tomography (micro-CT) in the laboratory, with a voxel size of 0.6x0.6x0.6microns3. The macroscopic permeability is calculated in two steps. On the small scale, the fracture transmissivity is calculated by solving the Stokes equation on several portions of the measured fissures by micro-CT. On the large scale, the density of the fissures is estimated by three different means based on the number of intersections with scanlines, on the surface density of fissures and on the intersections between fissures per unit surface. These three means show that the network is relatively isotropic and they provide very close estimations of the density. Then, a general formula derived from systematic numerical computations [2] is used to derive the macroscopic dimensionless permeability which is proportional to the fracture transmissivity. The combination of the two previous results yields the dimensional macroscopic permeability which is found to be in acceptable agreement with the experimental measurements. Some extensions of these preliminary works will be presented as a tentative conclusion. References [1] Z. Duan, C. A. Davy, F

  13. An efficient permeability scaling-up technique applied to the discretized flow equations

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    Urgelli, D.; Ding, Yu [Institut Francais du Petrole, Rueil Malmaison (France)


    Grid-block permeability scaling-up for numerical reservoir simulations has been discussed for a long time in the literature. It is now recognized that a full permeability tensor is needed to get an accurate reservoir description at large scale. However, two major difficulties are encountered: (1) grid-block permeability cannot be properly defined because it depends on boundary conditions; (2) discretization of flow equations with a full permeability tensor is not straightforward and little work has been done on this subject. In this paper, we propose a new method, which allows us to get around both difficulties. As the two major problems are closely related, a global approach will preserve the accuracy. So, in the proposed method, the permeability up-scaling technique is integrated in the discretized numerical scheme for flow simulation. The permeability is scaled-up via the transmissibility term, in accordance with the fluid flow calculation in the numerical scheme. A finite-volume scheme is particularly studied, and the transmissibility scaling-up technique for this scheme is presented. Some numerical examples are tested for flow simulation. This new method is compared with some published numerical schemes for full permeability tensor discretization where the full permeability tensor is scaled-up through various techniques. Comparing the results with fine grid simulations shows that the new method is more accurate and more efficient.

  14. Pore-Scale Simulation and Sensitivity Analysis of Apparent Gas Permeability in Shale Matrix. (United States)

    Zhang, Pengwei; Hu, Liming; Meegoda, Jay N


    Extremely low permeability due to nano-scale pores is a distinctive feature of gas transport in a shale matrix. The permeability of shale depends on pore pressure, porosity, pore throat size and gas type. The pore network model is a practical way to explain the macro flow behavior of porous media from a microscopic point of view. In this research, gas flow in a shale matrix is simulated using a previously developed three-dimensional pore network model that includes typical bimodal pore size distribution, anisotropy and low connectivity of the pore structure in shale. The apparent gas permeability of shale matrix was calculated under different reservoir pressures corresponding to different gas exploitation stages. Results indicate that gas permeability is strongly related to reservoir gas pressure, and hence the apparent permeability is not a unique value during the shale gas exploitation, and simulations suggested that a constant permeability for continuum-scale simulation is not accurate. Hence, the reservoir pressures of different shale gas exploitations should be considered. In addition, a sensitivity analysis was also performed to determine the contributions to apparent permeability of a shale matrix from petro-physical properties of shale such as pore throat size and porosity. Finally, the impact of connectivity of nano-scale pores on shale gas flux was analyzed. These results would provide an insight into understanding nano/micro scale flows of shale gas in the shale matrix.

  15. Compositional effects on relative permeability and hysteresis for enhanced oil recovery (United States)

    Khorsandi, S.; Li, L.; Johns, R. T.


    There are enormous efforts to develop relative permeability models that interpret pore scale flow mechanism into continuum scale observations. Relative permeabilities are complex functions of phase saturations, fluid compositions, pore structure, pore size distribution, interfacial properties, and distribution of phases. The current compositional reservoir simulators, however, are limited to use tuned correlations for relative permeabilities calculations. These correlations cannot quantify the more complex hysteresis, film drainage, capillary trapping or wettability alteration. Such processes are captured by adjusting the coefficients of relative permeability models based on capillary number, maximum non-wetting saturation, or phase compositions. Since the relative permeability models are not physical-based, the adjustments can result in inconsistency. The labeling of phases is another challenge for compositional floods, where phase properties can vary significantly such that phase inversion can happen. Therefore, common phase labeling techniques based on density or component tracking can fail. We proposed a novel compositional-dependent relative permeability model which calculates the phase flow rates based on pore structure, phase compositions, and phase distributions. This model can quantify many processes such as hysteresis, capillary trapping and film drainage, and does not require phase labeling. The effects of dissolution, vaporization and wettability alteration on relative permeabilities are also captured by the developed physical relative permeability model.

  16. Is the permeability of naturally fractured rocks scale dependent? (United States)

    Azizmohammadi, Siroos; Matthäi, Stephan K.


    The equivalent permeability, keq of stratified fractured porous rocks and its anisotropy is important for hydrocarbon reservoir engineering, groundwater hydrology, and subsurface contaminant transport. However, it is difficult to constrain this tensor property as it is strongly influenced by infrequent large fractures. Boreholes miss them and their directional sampling bias affects the collected geostatistical data. Samples taken at any scale smaller than that of interest truncate distributions and this bias leads to an incorrect characterization and property upscaling. To better understand this sampling problem, we have investigated a collection of outcrop-data-based Discrete Fracture and Matrix (DFM) models with mechanically constrained fracture aperture distributions, trying to establish a useful Representative Elementary Volume (REV). Finite-element analysis and flow-based upscaling have been used to determine keq eigenvalues and anisotropy. While our results indicate a convergence toward a scale-invariant keq REV with increasing sample size, keq magnitude can have multi-modal distributions. REV size relates to the length of dilated fracture segments as opposed to overall fracture length. Tensor orientation and degree of anisotropy also converge with sample size. However, the REV for keq anisotropy is larger than that for keq magnitude. Across scales, tensor orientation varies spatially, reflecting inhomogeneity of the fracture patterns. Inhomogeneity is particularly pronounced where the ambient stress selectively activates late- as opposed to early (through-going) fractures. While we cannot detect any increase of keq with sample size as postulated in some earlier studies, our results highlight a strong keq anisotropy that influences scale dependence.


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    Kishore K. Mohanty


    Recovery and recovery rate of oil, gas and condensates depend crucially on their relative permeability. Relative permeability in turn depends on the pore structure, wettability and flooding conditions, which can be represented by a set of dimensionless groups including capillary and bond numbers. The effect of flooding conditions on drainage relative permeabilities is not well understood and is the overall goal of this project. This project has three specific objectives: to improve the centrifuge relative permeability method, to measure capillary and bond number effects experimentally, and to develop a pore network model for multiphase flows. A centrifuge has been built that can accommodate high pressure core holders and x-ray saturation monitoring. The centrifuge core holders can operate at a pore pressure of 6.9 MPa (1000 psi) and an overburden pressure of 17 MPa (2500 psi). The effect of capillary number on residual saturation and relative permeability in drainage flow has been measured. A pore network model has been developed to study the effect of capillary numbers and viscosity ratio on drainage relative permeability. Capillary and Reynolds number dependence of gas-condensate flow has been studied during well testing. A method has been developed to estimate relative permeability parameters from gas-condensate well test data.

  18. Measurement of relative permeability of fuel cell diffusion media

    KAUST Repository

    Hussaini, I.S.


    Gas diffusion layer (GDL) in PEM fuel cells plays a pivotal role in water management. Modeling of liquid water transport through the GDL relies on knowledge of relative permeability functions in the in-plane and through-plane directions. In the present work, air and water relative permeabilities are experimentally determined as functions of saturation for typical GDL materials such as Toray-060, -090, -120 carbon paper and E-Tek carbon cloth materials in their plain, untreated forms. Saturation is measured using an ex situ gravimetric method. Absolute and relative permeability functions in the two directions of interest are presented and new correlations for in-plane relative permeability of water and air are established. © 2010 Elsevier B.V. All rights reserved.

  19. Three-scale analysis of the permeability of a natural shale (United States)

    Davy, C. A.; Adler, P. M.


    The macroscopic permeability of a natural shale is determined by using structural measurements on three different scales. Transmission electron microscopy yields two-dimensional (2D) images with pixels smaller than 1 nm; these images are used to reconstruct 3D nanostructures. Three-dimensional focused ion beam-scanning electron microscopy (5.95- to 8.48-nm voxel size) provides 3D mesoscale pores of limited relative volume (1.71-5.9%). Micro-computed tomography (700-nm voxel size) provides information on the mineralogy of the shale, including the pores on this scale which do not percolate; synthetic 3D media are derived on the macroscopic scale by a training image technique. Permeability of the nanoscale, of the mesoscale structures and of their superposition is determined by solving the Stokes equation and this enables us to estimate the permeabilities of the 700-nm voxels located within the clay matrix. Finally, the Darcy equation is solved on synthetic 3D macroscale media to obtain the macroscopic permeability which is found in good agreement with experimental results obtained on the centimetric scale.

  20. The Interfacial-Area-Based Relative Permeability Function

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    Zhang, Z. F.; Khaleel, Raziuddin


    CH2M Hill Plateau Remediation Company (CHPRC) requested the services of the Pacific Northwest National Laboratory (PNNL) to provide technical support for the Remediation Decision Support (RDS) activity within the Soil & Groundwater Remediation Project. A portion of the support provided in FY2009, was to extend the soil unsaturated hydraulic conductivity using an alternative approach. This alternative approach incorporates the Brooks and Corey (1964), van Genuchten (1980), and a modified van Genuchten water-retention models into the interfacial-area-based relative permeability model presented by Embid (1997). The general performance of the incorporated models is shown using typical hydraulic parameters. The relative permeability models for the wetting phase were further examined using data from literature. Results indicate that the interfacial-area-based model can describe the relative permeability of the wetting phase reasonably well.

  1. Analytical Estimation of Water-Oil Relative Permeabilities through Fractures

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    Saboorian-Jooybari Hadi


    Full Text Available Modeling multiphase flow through fractures is a key issue for understanding flow mechanism and performance prediction of fractured petroleum reservoirs, geothermal reservoirs, underground aquifers and carbon-dioxide sequestration. One of the most challenging subjects in modeling of fractured petroleum reservoirs is quantifying fluids competition for flow in fracture network (relative permeability curves. Unfortunately, there is no standard technique for experimental measurement of relative permeabilities through fractures and the existing methods are very expensive, time consuming and erroneous. Although, several formulations were presented to calculate fracture relative permeability curves in the form of linear and power functions of flowing fluids saturation, it is still unclear what form of relative permeability curves must be used for proper modeling of flow through fractures and consequently accurate reservoir simulation. Basically, the classic linear relative permeability (X-type curves are used in almost all of reservoir simulators. In this work, basic fluid flow equations are combined to develop a new simple analytical model for water-oil two phase flow in a single fracture. The model gives rise to simple analytic formulations for fracture relative permeabilities. The model explicitly proves that water-oil relative permeabilities in fracture network are functions of fluids saturation, viscosity ratio, fluids density, inclination of fracture plane from horizon, pressure gradient along fracture and rock matrix wettability, however they were considered to be only functions of saturations in the classic X-type and power (Corey [35] and Honarpour et al. [28, 29] models. Eventually, validity of the proposed formulations is checked against literature experimental data. The proposed fracture relative permeability functions have several advantages over the existing ones. Firstly, they are explicit functions of the parameters which are known for

  2. A fast Laplace solver approach to pore scale permeability (United States)

    Arns, Christoph; Adler, Pierre


    The permeability of a porous medium can be derived by solving the Stokes equations in the pore space with no slip at the walls. The resulting velocity averaged over the pore volume yields the permeability KS by application of the Darcy law. The Stokes equations can be solved by a number of different techniques such as finite differences, finite volume, Lattice Boltzmann, but whatever the technique it remains a heavy task since there are four unknowns at each node (the three velocity components and the pressure) which necessitate the solution of four equations (the projection of Newton's law on each axis and mass conservation). By comparison, the Laplace equation is scalar with a single unknown at each node. The objective of this work is to replace the Stokes equations by an elliptical equation with a space dependent permeability. More precisely, the local permeability k is supposed to be proportional to (r-alpha)**2 where r is the distance of the voxel to the closest wall, and alpha a constant; k is zero in the solid phase. The elliptical equation is div(k gradp)=0. A macroscopic pressure gradient is assumed to be exerted on the medium and again the resulting velocity averaged over space yields a permeability K_L. In order to validate this method, systematic calculations have been performed. First, elementary shapes (plane channel, circular pipe, rectangular channels) were studied for which flow occurs along parallel lines in which case KL is the arithmetic average of the k's. KL was calculated for various discretizations of the pore space and various values of alpha. For alpha=0.5, the agreement with the exact analytical value of KS is excellent for the plane and rectangular channels while it is only approximate for circular pipes. Second, the permeability KL of channels with sinusoidal walls was calculated and compared with analytical results and numerical ones provided by a Lattice Boltzmann algorithm. Generally speaking, the discrepancy does not exceed 25% when

  3. Relative permeability of hydrate-bearing sediments from percolation theory and critical path analysis: theoretical and experimental results

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    Daigle, Hugh [University of Texas at Austin; Rice, Mary Anna [North Carolina State University; Daigle, Hugh


    Relative permeabilities to water and gas are important parameters for accurate modeling of the formation of methane hydrate deposits and production of methane from hydrate reservoirs. Experimental measurements of gas and water permeability in the presence of hydrate are difficult to obtain. The few datasets that do exist suggest that relative permeability obeys a power law relationship with water or gas saturation with exponents ranging from around 2 to greater than 10. Critical path analysis and percolation theory provide a framework for interpreting the saturation-dependence of relative permeability based on percolation thresholds and the breadth of pore size distributions, which may be determined easily from 3-D images or gas adsorption-desorption hysteresis. We show that the exponent of the permeability-saturation relationship for relative permeability to water is related to the breadth of the pore size distribution, with broader pore size distributions corresponding to larger exponents. Relative permeability to water in well-sorted sediments with narrow pore size distributions, such as Berea sandstone or Toyoura sand, follows percolation scaling with an exponent of 2. On the other hand, pore-size distributions determined from argon adsorption measurements we performed on clays from the Nankai Trough suggest that relative permeability to water in fine-grained intervals may be characterized by exponents as large as 10 as determined from critical path analysis. We also show that relative permeability to the gas phase follows percolation scaling with a quadratic dependence on gas saturation, but the threshold gas saturation for percolation changes with hydrate saturation, which is an important consideration in systems in which both hydrate and gas are present, such as during production from a hydrate reservoir. Our work shows how measurements of pore size distributions from 3-D imaging or gas adsorption may be used to determine relative permeabilities.

  4. From Multi-Porosity to Multiple-Scale Permeability Models of Natural Fractured Media (United States)

    De Dreuzy, J. R.; Davy, P.; Meheust, Y.; Bour, O.


    Classical dual-porosity models and homogenization approaches fail to represent the permeability scaling, the high flow channeling and the broad variability observed in natural fractured media. More critically, most modeling frameworks cannot restitute simultaneously the permeability increase with scale and the persistence of channeling. In fact, channeling enhances the impact of bottlenecks, reduces permeability, and increases permeability variability with scale. It is the case of percolation theory but also of more advanced large-range correlated theories including power-law scaling of some of the fracture properties including their length or their mutual distances. More generally, we show with extensive numerical studies on 3D Discrete Fracture Networks (DFNs) that hydraulic behaviors come from a number of local and global fracture characteristics. The concept of effective properties like effective permeability itself appears quite weak and should be replaced by new modeling frameworks. We propose three alternative approaches combining the specificies of fracture flow and transport of DFNs and the simplicity of continuum approaches: 1- Discrete dual porosity media for high flow localization in a subset of the fracture network. 2- Structured Interacting Continua for highly organized diffusive processes in poorly connected fracture structures. 3- Multiple-scale permeability models for hierarchically structured fractured media with 3D concurrent fracture percolating networks. These different approaches can be combined and specified with a limited number of parameters. They are also efficient in representing the potentially large hydraulic impact of minor modification of the fracture network geometry and local connectivity.

  5. Improvements in scaling of counter-current imbibition recovery curves using a shape factor including permeability anisotropy (United States)

    Abbasi, Jassem; Sarafrazi, Shiva; Riazi, Masoud; Ghaedi, Mojtaba


    Spontaneous imbibition is the main oil production mechanism in the water invaded zone of a naturally fractured reservoir (NFR). Different scaling equations have been presented in the literature for upscaling of core scale imbibition recovery curves to field scale matrix blocks. Various scale dependent parameters such as gravity effects and boundary influences are required to be considered in the upscaling process. Fluid flow from matrix blocks to the fracture system is highly dependent on the permeability value in the horizontal and vertical directions. The purpose of this study is to include permeability anisotropy in the available scaling equations to improve the prediction of imbibition assisted oil production in NFRs. In this paper, a commercial reservoir simulator was used to obtain imbibition recovery curves for different scenarios. Then, the effect of permeability anisotropy on imbibition recovery curves was investigated, and the weakness of the existing scaling equations for anisotropic rocks was demonstrated. Consequently, an analytical shape factor was introduced that can better scale all the curves related to anisotropic matrix blocks.

  6. Effects of phase transformation of steam-water relative permeabilities

    Energy Technology Data Exchange (ETDEWEB)

    Verma, A.K.


    A combined theoretical and experimental study of steam-water relative permeabilities (RPs) was carried out. First, an experimental study of two-phase concurrent flow of steam and water was conducted and a set of RP curves was obtained. These curves were compared with semi-empirical and experimental results obtained by other investigators for two-phase, two-component flow (oil/gas; gas/water; gas/oil). It was found that while the wetting phase RPs were in good agreement, RPs for the steam phase were considerably higher than the non-wetting phase RPs in two-component systems. This enhancement of steam RP is attributed to phase transformation effects at the pore level in flow channels. The effects of phase transformation were studied theoretically. This study indicates that there are two separate mechanisms by which phase transformation affects RP curves: (1) Phase transformation is converging-diverging flow channels can cause an enhancement of steam phase RP. In a channel dominated by steam a fraction of the flowing steam condenses upstream from the constriction, depositing its latent heat of condensation. This heat is conducted through the solid grains around the pore throat, and evaporation takes place downstream from it. Therefore, for a given bulk flow quality; a smaller fraction of steam actually flows through the throat segments. This pore-level effect manifests itself as relative permeability enhancement on a macroscopic level; and (2) phase transformation along the interface of a stagnant phase and the phase flowing around it controls the irreducible phase saturation. Therefore, the irreducible phase saturation in steam-water flow will depend, among other factors, on the boundary conditions of the flow.

  7. Basin scale permeability and thermal evolution of a magmatic hydrothermal system (United States)

    Taron, J.; Hickman, S. H.; Ingebritsen, S.; Williams, C.


    Large-scale hydrothermal systems are potentially valuable energy resources and are of general scientific interest due to extreme conditions of stress, temperature, and reactive chemistry that can act to modify crustal rheology and composition. With many proposed sites for Enhanced Geothermal Systems (EGS) located on the margins of large-scale hydrothermal systems, understanding the temporal evolution of these systems contributes to site selection, characterization and design of EGS. This understanding is also needed to address the long-term sustainability of EGS once they are created. Many important insights into heat and mass transfer within natural hydrothermal systems can be obtained through hydrothermal modeling assuming that stress and permeability structure do not evolve over time. However, this is not fully representative of natural systems, where the effects of thermo-elastic stress changes, chemical fluid-rock interactions, and rock failure on fluid flow and thermal evolution can be significant. The quantitative importance of an evolving permeability field within the overall behavior of a large-scale hydrothermal system is somewhat untested, and providing such a parametric understanding is one of the goals of this study. We explore the thermal evolution of a sedimentary basin hydrothermal system following the emplacement of a magma body. The Salton Sea geothermal field and its associated magmatic system in southern California is utilized as a general backdrop to define the initial state. Working within the general framework of the open-source scientific computing initiative OpenGeoSys (, we introduce full treatment of thermodynamic properties at the extreme conditions following magma emplacement. This treatment utilizes a combination of standard Galerkin and control-volume finite elements to balance fluid mass, mechanical deformation, and thermal energy with consideration of local thermal non-equilibrium (LTNE) between fluids and solids

  8. Simulating gas-water relative permeabilities for nanoscale porous media with interfacial effects

    Directory of Open Access Journals (Sweden)

    Wang Jiulong


    Full Text Available This paper presents a theoretical method to simulate gas-water relative permeability for nanoscale porous media utilizing fractal theory. The comparison between the calculation results and experimental data was performed to validate the present model. The result shows that the gas-water relative permeability would be underestimated significantly without interfacial effects. The thinner the liquid film thickness, the greater the liquid-phase relative permeability. In addition, both liquid surface diffusion and gas diffusion coefficient can promote gas-liquid two-phase flow. Increase of liquid surface diffusion prefer to increase liquid-phase permeability obviously as similar as increase of gas diffusion coefficient to increase gas-phase permeability. Moreover, the pore structure will become complicated with the increase of fractal dimension, which would reduce the gas-water relative permeability. This study has provided new insights for development of gas reservoirs with nanoscale pores such as shale.

  9. Verification of capillary pressure functions and relative permeability equations for gas production

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Jaewon [Arizona State Univ., Tempe, AZ (United States)


    The understanding of multiphase fluid flow in porous media is of great importance in many fields such as enhanced oil recovery, hydrology, CO2 sequestration, contaminants cleanup and natural gas production from hydrate bearing sediments. However, there are many unanswered questions about the key parameters that characterize gas and water flows in porous media. The characteristics of multiphase fluid flow in porous media such as water retention curve, relative permeability, preferential fluid flow patterns and fluid-particle interaction should be taken into consideration for a fundamental understanding of the behavior of pore scale systems.

  10. Extended power-law scaling of air permeabilities measured on a block of tuff


    Siena, M; Guadagnini, A.; Riva, M; S. P. Neuman


    We use three methods to identify power-law scaling of multi-scale log air permeability data collected by Tidwell and Wilson on the faces of a laboratory-scale block of Topopah Spring tuff: method of moments (M), Extended Self-Similarity (ESS) and a generalized version thereof (G-ESS). All three methods focus on q-th-order sample structure functions of absolute increments. Most such functions exhibit power-law scaling at best over a limited midrange of experimental separatio...

  11. Extended power-law scaling of air permeabilities measured on a block of tuff


    Siena, M; Guadagnini, A.; Riva, M; S. P. Neuman


    We use three methods to identify power law scaling of (natural) log air permeability data collected by Tidwell and Wilson (1999) on the faces of a laboratory-scale block of Topopah Spring tuff: method of moments (M), extended power-law scaling also known as Extended Self-Similarity (ESS) and a generalized version thereof (G-ESS). All three methods focus on qth-order sample structure functions of absolute increments. Most such functions exhibit power-law scaling at best over...

  12. Permeability and hydraulic diffusivity of Waste Isolation Pilot Plant repository salt inferred from small-scale brine inflow experiments

    Energy Technology Data Exchange (ETDEWEB)

    McTigue, D.F.


    Brine seepage to 17 boreholes in salt at the Waste Isolation Pilot Plant (WIPP) facility horizon has been monitored for several years. A simple model for one-dimensional, radial, darcy flow due to relaxation of ambient pore-water pressure is applied to analyze the field data. Fits of the model response to the data yield estimates of two parameters that characterize the magnitude of the flow and the time scale over which it evolves. With further assumptions, these parameters are related to the permeability and the hydraulic diffusivity of the salt. For those data that are consistent with the model prediction, estimated permeabilities are typically 10{sup {minus}22} to 10{sup {minus}21} m{sup 2}. The relatively small range of inferred permeabilities reflects the observation that the measured seepage fluxes are fairly consistent from hole to hole, of the order of 10{sup {minus}10} m/s. Estimated diffusivities are typically 10{sup {minus}10} to 10{sup {minus}8} m{sup 2}/s. The greater scatter in inferred hydraulic diffusivities is due to the difficulty of matching the idealized model history to the observed evolution of the flows. The data obtained from several of the monitored holes are not consistent with the simple model adopted here; material properties could not be inferred in these cases.

  13. Oxygen Permeability and Grain-Boundary Diffusion Applied to Alumina Scales (United States)

    Smialek, James L.; Jacobson, Nathan S.; Gleeson, Brian; Hovis, David B.; Heuer, Arthur H.


    High-temperature oxygen permeability measurements had determined grain-boundary diffusivities (deltaD(sub gb)) in bulk polycrystalline alumina (Wada, Matsudaira, and Kitaoka). They predict that oxygen deltaD(sub gb,O) varies with oxygen pressure as P(O2)(sup -1/6) at low pressure whereas aluminum deltaD(sub gb),Al varies with P(O2)(sup +3/16) at high pressure. These relations were used to evaluate alumina scale growth in terms of diffusivity and grain size. A modified Wagner treatment for dominant inward oxygen growth produces the concise solution: ?(sub i) = k(sub p,i)×G(sub i) = 12 deltaD(sub gb,O,int), where ?(sub i) is a constant and k(sub p,i) and G(sub i) refer to instantaneous values of the scale parabolic growth constant and grain size, respectively. A commercial FeCrAl(Zr) alloy was oxidized at 1100 to 1400 degC to determine k(sub p,i), interfacial grain size, ?, and thus deltaD(sub gb,O,int). The deltaD(sub gb,O,int) values predicted from oxidation at (375 kJ/mole) were about 20 times less than those obtained above (at 298 kJ/mole), but closer than extrapolations from high-temperature bulk measurements. The experimental oxidation results agree with similar FeCrAl(X) studies, especially where both k(sub p,i) and G(sub i) were characterized. This complete approach accounts for temperature-sensitive oxidation effects of grain enlargement, equilibrium interface pressure variation, and grain-boundary diffusivity.

  14. Relative permeabilities of supercritical CO2 and brine in carbon sequestration by a two-phase lattice Boltzmann method (United States)

    Xie, Jian.-Fei.; He, S.; Zu, Y. Q.; Lamy-Chappuis, B.; Yardley, B. W. D.


    In this paper, the migration of supercritical carbon dioxide (CO2) in realistic sandstone rocks under conditions of saline aquifers, with applications to the carbon geological storage, has been investigated by a two-phase lattice Boltzmann method (LBM). Firstly the digital images of sandstone rocks were reproduced utilizing the X-ray computed microtomography (micro-CT), and high resolutions (up to 2.5 μm) were applied to the pore-scale LBM simulations. For the sake of numerical stability, the digital images were "cleaned" by closing the dead holes and removing the suspended particles in sandstone rocks. In addition, the effect of chemical reactions occurred in the carbonation process on the permeability was taken into account. For the wetting brine and non-wetting supercritical CO2 flows, they were treated as the immiscible fluids and were driven by pressure gradients in sandstone rocks. Relative permeabilities of brine and supercritical CO2 in sandstone rocks were estimated. Particularly the dynamic saturation was applied to improve the reliability of the calculations of the relative permeabilities. Moreover, the effects of the viscosity ratio of the two immiscible fluids and the resolution of digital images on the relative permeability were systematically investigated.

  15. Permeability of fiber reinforcements for liquid composite molding: Sequential multi-scale investigations into numerical flow modeling on the micro- and meso-scale (United States)

    Luchini, Timothy John Franklin

    Composites are complex material mixtures, known to have high amounts of variability, with unique properties at the micro-, meso-, and macro-scales. In the context of advanced textile composite reinforcements, micro-scale refers to aligned fibers and toughening agents in a disordered arrangement; meso-scale is the woven, braided, or stitched fabric geometry (which compacts to various volume fractions); and macro-scale is the component or sub-component being produced for a mechanical application. The Darcy-based permeability is an important parameter for modeling and understanding the flow profile and fill times for liquid composite molding. Permeability of composite materials can vary widely from the micro- to macro-scales. For example, geometric factors like compaction and ply layup affect the component permeability at the meso- and macro-scales. On the micro-scale the permeability will be affected by the packing arrangement of the fibers and fiber volume fraction. On any scale, simplifications to the geometry can be made to treat the fiber reinforcement as a porous media. Permeability has been widely studied in both experimental and analytical frameworks, but less attention has focused on the ability of numerical tools to predict the permeability of reinforced composite materials. This work aims at (1) predicting permeability at various scales of interest and (2) developing a sequential, multi-scale, numerical modeling approach on the micro- and meso-scales. First, a micro-scale modeling approach is developed, including a geometry generation tool and a fluids-based numerical permeability solver. This micro-scale model included all physical fibers and derived the empirical permeability constant directly though numerical simulation. This numerical approach was compared with literature results for perfect packing arrangements, and the results were shown to be comparable with previous work. The numerical simulations described here also extended these previous

  16. On the Relation Between Transient Elastic Softening and Permeability Increase in fractured shale and granite (United States)

    Riviere, J.; Madara, B.; Elsworth, D.; Johnson, P. A.; Marone, C.


    Dynamic stressing of rocks is known to transiently increase permeability, and has potential application to improve the efficiency of geothermal energy production and oil/gas recovery. At larger scale, teleseismic waves have been observed to transiently increase permeability of aquifer systems. Seismic waves are also known to transiently decrease elastic moduli near fault zones. However, it remains unclear which parameters control the magnitude of permeability increase and how this magnitude can be predicted. We report on laboratory studies that monitor both permeability evolution and elastic properties in fractured granite and shale. We use L-shaped samples that are loaded with triaxial stresses of order 10 MPa and fractured in a triaxial cell. Deionized water is forced to flow along the resulting fracture path by applying a differential pore pressure along the shear direction. Dynamic stressing is applied via pore pressure or normal stress oscillations (20 s-duration, up to 1 Hz-frequency and 1 MPa-amplitude), while measuring flow rates and elastic wave velocities. Our observations enable transient increases in permeability to be determined following dynamic stressing and constrained via measurements of ultrasonic velocity. In particular, these preliminary results are discussed with former results suggesting that permeability enhancement is dictated by flow rate.

  17. Field-scale forward and back diffusion through low-permeability zones (United States)

    Yang, Minjune; Annable, Michael D.; Jawitz, James W.


    Understanding the effects of back diffusion of groundwater contaminants from low-permeability zones to aquifers is critical to making site management decisions related to remedial actions. Here, we combine aquifer and aquitard data to develop recommended site characterization strategies using a three-stage classification of plume life cycle based on the solute origins: aquifer source zone dissolution, source zone dissolution combined with back diffusion from an aquitard, and only back diffusion. We use measured aquitard concentration profile data from three field sites to identify signature shapes that are characteristic of these three stages. We find good fits to the measured data with analytical solutions that include the effects of advection and forward and back diffusion through low-permeability zones, and linearly and exponentially decreasing flux resulting from source dissolution in the aquifer. Aquifer contaminant time series data at monitoring wells from a mature site were well described using analytical solutions representing the combined case of source zone and back diffusion, while data from a site where the source had been isolated were well described solely by back diffusion. The modeling approach presented in this study is designed to enable site managers to implement appropriate remediation technologies at a proper timing for high- and low-permeability zones, considering estimated plume life cycle.

  18. Evolving simple-to-use method to determine water–oil relative permeability in petroleum reservoirs

    Directory of Open Access Journals (Sweden)

    Mohammad Ali Ahmadi


    Full Text Available In the current research, a new approach constructed based on artificial intelligence concept is introduced to determine water/oil relative permeability at various conditions. To attain an effective tool, various artificial intelligence approaches such as artificial neural network (ANN, hybrid of genetic algorithm and particle swarm optimization (HGAPSO are examined. Intrinsic potential of feed-forward artificial neural network (ANN optimized by different optimization algorithms are composed to estimate water/oil relative permeability. The optimization methods such as genetic algorithm, particle swarm optimization and hybrid approach of them are implemented to obtain optimal connection weights involved in the developed smart technique. The constructed intelligent models are evaluated by utilizing extensive experimental data reported in open literature. Results obtained from the proposed intelligent tools were compared with the corresponding experimental relative permeability data. The average absolute deviation between the model predictions and the relevant experimental data was found to be less than 0.1% for hybrid genetic algorithm and particle swarm optimization technique. It is expected that implication of HGAPSO-ANN in relative permeability of water/oil estimation leads to more reliable water/oil relative permeability predictions, resulting in design of more comprehensive simulation and further plans for reservoir production and management.

  19. Permeability of skin and oral mucosa to water and horseradish peroxidase as related to the thickness of the permeability barrier

    Energy Technology Data Exchange (ETDEWEB)

    Squier, C.A.; Hall, B.K.


    The permeability of porcine skin and keratinized and nonkeratinized oral mucosa to tritium-labeled water and horseradish peroxidase (HRPO) was determined using perfusion chambers. Small blocks from each tissue were also incubated with HRPO and the extent of penetration visualized microscopically; this enabled measurements to be made of the thickness of the permeability barrier to this water-soluble tracer. Results obtained after inverting the oral mucosa in the chambers or adding metabolic inhibitors indicated that both compounds diffuse across the tissue. The permeability constants derived directly in the study showed that skin was less permeable than oral mucosa and that the floor of the mouth was significantly more permeable than all other regions. When these constants were normalized in terms of a standard permeability barrier thickness and the different tissues compared, the values obtained for skin were again less than those of the oral regions but, of these, the buccal mucosa was significantly higher. The difference in permeability between epidermis and keratinized oral epithelium may be due to differences in the volume density of membrane-coating granules known to exist between the tissues; differences between the oral mucosal regions may reflect differences in the nature of the intercellular barrier material.

  20. Experimental Measurement of Relative Permeability Functions for Fuel Cell GDL Materials

    KAUST Repository

    Hussaini, Irfan


    Gas diffusion layer in PEM fuel cells plays a pivotal role in water management. Modeling of liquid water transport through the GDL relies on knowledge of relative permeability functions in the in-plane and through-plane directions. In the present work, air and water relative permeabilities are experimentally determined as functions of saturation for typical GDL materials such as Toray-060, -090, -120 carbon paper and E-Tek carbon cloth materials in their plain, untreated forms. Saturation is measured using an ex-situ gravimetric method. Absolute and relative permeability functions in the two directions of interest are presented. Significant departure from the generally assumed cubic function of saturation is observed. ©The Electrochemical Society.

  1. A study of relative permeability parameters on rock cores using a two-phase flow test

    Directory of Open Access Journals (Sweden)

    Chung-Hui Chiao


    Full Text Available To ensure sequestration safety, confirming the injectivity of the reservoir rock formation is of critical importance, requiring studies of the rock permeability to uncover the fluid migration scenarios within the porous reservoir rock. Two-phase (super-critical CO2-brine flow behavior following the post CO2 injection is believed to be a dominating factor; its flooding behavior within the porous rock media needs to be further clarified prior to confirming the feasibility of domestic CO2 geo-sequestration. This study aims to determine the relative permeability of rock cores obtained from field outcropping. A test facility was established to determine the relative permeability during drainage and imbibition processes using a core-flooding test characterized by displacement method. The test facility was assembled locally and is regarded as a pioneering attempt. By relevant data interpretation, the parameters of relative permeability for predicting the movement of super-critical CO2 after injection can be modeled. More reliable parameters can be obtained using history matching processes wherein time-elapsed data calibration is used in conjunction with a computer code, TOUGH2. The test results were iteratively calibrated using numerical simulation by conducting a history matching process. The K-S curves derived from best-fit parameters are believed to be the most relevant relative permeability for the reservoir rock. Through this preliminary study, a better understanding of some of the problems and limitations associated with the determination of the rock relative permeability using two-phase flow test is achieved, but more advanced research is required.

  2. Predicting permeability of regular tissue engineering scaffolds: scaling analysis of pore architecture, scaffold length, and fluid flow rate effects. (United States)

    Rahbari, A; Montazerian, H; Davoodi, E; Homayoonfar, S


    The main aim of this research is to numerically obtain the permeability coefficient in the cylindrical scaffolds. For this purpose, a mathematical analysis was performed to derive an equation for desired porosity in terms of morphological parameters. Then, the considered cylindrical geometries were modeled and the permeability coefficient was calculated according to the velocity and pressure drop values based on the Darcy's law. In order to validate the accuracy of the present numerical solution, the obtained permeability coefficient was compared with the published experimental data. It was observed that this model can predict permeability with the utmost accuracy. Then, the effect of geometrical parameters including porosity, scaffold pore structure, unit cell size, and length of the scaffolds as well as entrance mass flow rate on the permeability of porous structures was studied. Furthermore, a parametric study with scaling laws analysis of sample length and mass flow rate effects on the permeability showed good fit to the obtained data. It can be concluded that the sensitivity of permeability is more noticeable at higher porosities. The present approach can be used to characterize and optimize the scaffold microstructure due to the necessity of cell growth and transferring considerations.

  3. Evaluating the Influence of Pore Architecture and Initial Saturation on Wettability and Relative Permeability in Heterogeneous, Shallow-Shelf Carbonates

    Energy Technology Data Exchange (ETDEWEB)

    Byrnes, Alan P.; Bhattacharya, Saibal; Victorine, John; Stalder, Ken


    Thin (3-40 ft thick), heterogeneous, limestone and dolomite reservoirs, deposited in shallow-shelf environments, represent a significant fraction of the reservoirs in the U.S. midcontinent and worldwide. In Kansas, reservoirs of the Arbuckle, Mississippian, and Lansing-Kansas City formations account for over 73% of the 6.3 BBO cumulative oil produced over the last century. For these reservoirs basic petrophysical properties (e.g., porosity, absolute permeability, capillary pressure, residual oil saturation to waterflood, resistivity, and relative permeability) vary significantly horizontally, vertically, and with scale of measurement. Many of these reservoirs produce from structures of less than 30-60 ft, and being located in the capillary pressure transition zone, exhibit vertically variable initial saturations and relative permeability properties. Rather than being simpler to model because of their small size, these reservoirs challenge characterization and simulation methodology and illustrate issues that are less apparent in larger reservoirs where transition zone effects are minor and most of the reservoir is at saturations near S{sub wirr}. These issues are further augmented by the presence of variable moldic porosity and possible intermediate to mixed wettability and the influence of these on capillary pressure and relative permeability. Understanding how capillary-pressure properties change with rock lithology and, in turn, within transition zones, and how relative permeability and residual oil saturation to waterflood change through the transition zone is critical to successful reservoir management and as advanced waterflood and improved and enhanced recovery methods are planned and implemented. Major aspects of the proposed study involve a series of tasks to measure data to reveal the nature of how wettability and drainage and imbibition oil-water relative permeability change with pore architecture and initial water saturation. Focus is placed on

  4. Permittivity and permeability measurements methods for particle accelerator related materials

    CERN Document Server

    Vollinger, C; Jensen, E


    For the special requirements related to particle accelerators, knowledge of the different material parameters of dielectrics and other materials are needed in order to carry out simulations during the design process of accelerator components. This includes also properties of magnetically biased ferrites of which usually little information is available about material characteristics, especially in magnetic bias fields. Several methods of measurement are discussed and compared of which some require delicate sample preparation whereas others can work with unmodified material shapes that makes those methods also suited for acceptance checks on incoming materials delivered by industry. Applications include characterization of different materials, as absorbers in which dielectric losses play an increasing role, as well as low frequency measurements on ferrites that are used for tunable cavities. We present results obtained from both broadband and resonant measurements on different materials determined in the same s...

  5. Effect of Temperature, Wettability and Relative Permeability on Oil Recovery from Oil-wet Chalk

    Directory of Open Access Journals (Sweden)

    Omid Karoussi


    Full Text Available It is customary, for convenience, to use relative permeability data produced at room temperature. This paper shows that this practice underestimates oil recovery rates and ultimate recovery from chalk rocks for high temperature reservoirs. Above a certain temperature (80°C in this work a reduction of oil recovery was observed. The reduction in oil recovery is reflected by the shift of relative permeability data towards more oil-wet at high temperature (tested here 130°C. However, both IFT and contact angle measurements indicate an increase in water wetness as temperature increases, which contradict the results obtained by relative permeability experiments. This phenomenon may be explained based on the total interaction potential, which basically consists of van der Waals attractive and short-range Born repulsive and double layer electrostatic forces. The fluid/rock interactions is shown to be dominated by the repulsive forces above 80°C, hence increase fine detachment enhancing oil trapping. In other words the indicated oil wetness by relative permeability is misleading.

  6. Evaluating the Infiltration Performance of Eight Dutch Permeable Pavements Using a New Full-Scale Infiltration Testing Method

    Directory of Open Access Journals (Sweden)

    Floris Boogaard


    Full Text Available Permeable pavements are a type of sustainable urban drainage system (SUDS technique that are used around the world to infiltrate and treat urban stormwater runoff and to minimize runoff volumes. Urban stormwater runoff contains significant concentrations of suspended sediments that can cause clogging and reduce the infiltration capacity and effectiveness of permeable pavements. It is important for stormwater managers to be able to determine when the level of clogging has reached an unacceptable level, so that they can schedule maintenance or replacement activities as required. Newly-installed permeable pavements in the Netherlands must demonstrate a minimum infiltration capacity of 194 mm/h (540 l/s/ha. Other commonly used permeable pavement guidelines in the Netherlands recommend that maintenance is undertaken on permeable pavements when the infiltration falls below 0.50 m/d (20.8 mm/h. This study used a newly-developed, full-scale infiltration test procedure to evaluate the infiltration performance of eight permeable pavements in five municipalities that had been in service for over seven years in the Netherlands. The determined infiltration capacities vary between 29 and 342 mm/h. Two of the eight pavements show an infiltration capacity higher than 194 mm/h, and all infiltration capacities are higher than 20.8 mm/h. According to the guidelines, this suggests that none of the pavements tested in this study would require immediate maintenance.

  7. Identification of small-scale low and high permeability layers using single well forced-gradient tracer tests: fluorescent dye imaging and modelling at the laboratory-scale. (United States)

    Barns, Gareth L; Thornton, Steven F; Wilson, Ryan D


    Heterogeneity in aquifer permeability, which creates paths of varying mass flux and spatially complex contaminant plumes, can complicate the interpretation of contaminant fate and transport in groundwater. Identifying the location of high mass flux paths is critical for the reliable estimation of solute transport parameters and design of groundwater remediation schemes. Dipole flow tracer tests (DFTTs) and push-pull tests (PPTs) are single well forced-gradient tests which have been used at field-scale to estimate aquifer hydraulic and transport properties. In this study, the potential for PPTs and DFTTs to resolve the location of layered high- and low-permeability layers in granular porous media was investigated with a pseudo 2-D bench-scale aquifer model. Finite element fate and transport modelling was also undertaken to identify appropriate set-ups for in situ tests to determine the type, magnitude, location and extent of such layered permeability contrasts at the field-scale. The characteristics of flow patterns created during experiments were evaluated using fluorescent dye imaging and compared with the breakthrough behaviour of an inorganic conservative tracer. The experimental results show that tracer breakthrough during PPTs is not sensitive to minor permeability contrasts for conditions where there is no hydraulic gradient. In contrast, DFTTs are sensitive to the type and location of permeability contrasts in the host media and could potentially be used to establish the presence and location of high or low mass flux paths. Numerical modelling shows that the tracer peak breakthrough time and concentration in a DFTT is sensitive to the magnitude of the permeability contrast (defined as the permeability of the layer over the permeability of the bulk media) between values of 0.01-20. DFTTs are shown to be more sensitive to deducing variations in the contrast, location and size of aquifer layered permeability contrasts when a shorter central packer is used

  8. Numerical Modelling of Thermal Convection Related to Fracture Permeability - Implications for Geothermal Exploration and Basin Modelling (United States)

    Lipsey, Lindsay; van Wees, Jan-Diederik; Pluymaekers, Maarten; Cloetingh, Sierd


    Thermal anomalies in deep sedimentary settings are largely controlled by fluid circulation within permeable zones. Convection is of particular interest in geothermal exploration, as it creates areas with anomalously high temperatures at shallow depths. Recent work on the temperature distribution in the Dutch subsurface revealed a thermal anomaly at the Luttelgeest-01 (LTG-01) at 4-5 km depth, which could be explained by thermal convection. Temperature measurements show a shift to higher temperatures at depths greater than 4000 m, corresponding the Dinantian carbonates. In order for convective heat transport to explain the anomaly, there must also be sufficient permeability. Rayleigh number calculations show that convection may be possible within the Dinantian carbonate layer, depending on its thickness, permeability and geothermal gradient. For example, an average permeability of 60 mD permits convection in a 600 m aquifer, given a geothermal gradient of 31°C/km. If the permeability is reduced to 20 mD, convection can only occur where the thickness of the aquifer is greater than 900 m. Interestingly, numerical simulations were able to come within 5-10 mD of the theoretical minimum permeability values calculated for each scenario. 3D numerical simulations provide insight on possible flow and thermal structures within the fractured carbonate interval, as well as illustrate the role of permeability on the timing of convection onset, convection cell structure development and the resulting temperature patterns. The development and number of convection cells is very much a time dependent process. Many cells may develop in the beginning of simulations, but they seem to gradually converge until steady state is reached. The shape of convective upwellings varies from roughly circular or hexagonal to more elongated upwellings and downwellings. Furthermore, the geometric aspects of the carbonate platform itself likely control the shape and location of upwellings, as well as

  9. Evaluation of methods for measuring relative permeability of anhydride from the Salado Formation: Sensitivity analysis and data reduction

    Energy Technology Data Exchange (ETDEWEB)

    Christiansen, R.L.; Kalbus, J.S. [Colorado School of Mines, Golden, CO (United States). Petroleum Engineering Dept.; Howarth, S.M. [Sandia National Labs., Albuquerque, NM (United States)


    This report documents, demonstrates, evaluates, and provides theoretical justification for methods used to convert experimental data into relative permeability relationships. The report facilities accurate determination of relative permeabilities of anhydride rock samples from the Salado Formation at the Waste Isolation Pilot Plant (WIPP). Relative permeability characteristic curves are necessary for WIPP Performance Assessment (PA) predictions of the potential for flow of waste-generated gas from the repository and brine flow into repository. This report follows Christiansen and Howarth (1995), a comprehensive literature review of methods for measuring relative permeability. It focuses on unsteady-state experiments and describes five methods for obtaining relative permeability relationships from unsteady-state experiments. Unsteady-state experimental methods were recommended for relative permeability measurements of low-permeability anhydrite rock samples form the Salado Formation because these tests produce accurate relative permeability information and take significantly less time to complete than steady-state tests. Five methods for obtaining relative permeability relationships from unsteady-state experiments are described: the Welge method, the Johnson-Bossler-Naumann method, the Jones-Roszelle method, the Ramakrishnan-Cappiello method, and the Hagoort method. A summary, an example of the calculations, and a theoretical justification are provided for each of the five methods. Displacements in porous media are numerically simulated for the calculation examples. The simulated product data were processed using the methods, and the relative permeabilities obtained were compared with those input to the numerical model. A variety of operating conditions were simulated to show sensitivity of production behavior to rock-fluid properties.

  10. Compositional and Relative Permeability Hysteresis Effects on Near-Miscible WAG

    DEFF Research Database (Denmark)

    Christensen, Jes Reimer; Stenby, Erling Halfdan; Skauge, Arne


    Evaluation of compositional effects and fluid flow description on near-miscible (water-alternating-gas) WAG modeling have been studied for a North Sea oil field starting production in 1998. A sector model with four wells was applied to simulate a heterogeneous sandstone reservoir...... injection gases. Result obtained shows the WAG injection gives improved recovery compared to water injection, due to better sweep and lower residual oil saturation. Simulations with and without relative permeability hysteresis (two-phase model) were compared. The effect of trapped gas on oil recovery does...... not seem significant with the compositional model. The WAG process has been optimized with respect to slug size and the water-gas ratio. A black-oil-model was generated tuned to fit the results from the compositional simulations. A WAG three-phase relative permeability hysteresis model using cycle...

  11. Laboratory-Scale Experiments of the Methane Hydrate Dissociation Process in a Porous Media and Numerical Study for the Estimation of Permeability in Methane Hydrate Reservoir

    Directory of Open Access Journals (Sweden)

    Yasuhide Sakamoto


    Full Text Available An experimental study of the dissociation of methane hydrate (MH by hot-water injection and depressurization was carried out at the National Institute of Advanced Industrial Science and Technology (AIST. These experiments helped us understand some important aspects of MH behavior such as how temperature, pressure, and permeability change during dissociation and gas production. In order to understand the experimental results, a model of MH dissociation in a porous media was designed and implemented in a numerical simulator. In the model, we treated the MH phase as a two-component system by representing the pore space occupied by MH as a separate component. Absolute permeability and relative permeability were formulated as a function of MH saturation, porosity, and sand grain diameter and introduced into the numerical model. Using the developed numerical simulator, we attempted history matching of laboratory-scale experiments of the MH dissociation process. It was found that numerical simulator was able to reproduce temperature change, permeability characteristics, and gas production behavior associated with both MH formation and dissociation.

  12. Relation of transverse air permeability with physical properties in different compositions of sugarcane bagasse particleboards

    Directory of Open Access Journals (Sweden)

    Lina Bufalino


    Full Text Available Studies concerning the production of particleboards with sugarcane bagasse as an alternative fibrous material have been carried out as an attempt to provide a sustainable and viable destination for this residue. This work aimed to evaluate the influence of several processing variables related to the microstructure of sugarcane bagasse particleboards (mat type, adhesive type and adhesive content on their permeability and water sorption properties. Air permeability data was collected by the rotameter method. Superficial air permeability (kg, Darcian constant (k1 and non-Darcian constant (k2 were measured. kg was related to sorption behavior of the particleboards. 1-layer particleboards presented significantly higher kg values than the 3-layer particleboards. In general, adhesive type, position and content did not influence kg of particleboards. However, these processing variables influenced interactions between fluid and material and tortuosity of the porous media. Particleboards produced with urea-formaldehyde with high kg presented higher water absorption and thickness swelling after 24 hours. Such relations were not observed in particleboards produced with melamine-urea-formaldehyde.

  13. Relation of transverse air permeability with physical properties in different compositions of sugarcane bagasse particleboards

    Directory of Open Access Journals (Sweden)

    Lina Bufalino


    Full Text Available Studies concerning the production of particleboards with sugarcane bagasse as an alternative fibrous material have been carried out as an attempt to provide a sustainable and viable destination for this residue. This work aimed to evaluate the influence of several processing variables related to the microstructure of sugarcane bagasse particleboards (mat type, adhesive type and adhesive content on their permeability and water sorption properties. Air permeability data was collected by the rotameter method. Superficial air permeability (kg, Darcian constant (k1 and non-Darcian constant (k2 were measured. kg was related to sorption behavior of the particleboards. 1-layer particleboards presented significantly higher kg values than the 3-layer particleboards. In general, adhesive type, position and content did not influence kg of particleboards. However, these processing variables influenced interactions between fluid and material and tortuosity of the porous media. Particleboards produced with urea-formaldehyde with high kg presented higher water absorption and thickness swelling after 24 hours. Such relations were not observed in particleboards produced with melamine-urea-formaldehyde.

  14. The relevance of capillary pressure for the concept of relative permeability. A model for multiphase flow in porous media

    Energy Technology Data Exchange (ETDEWEB)

    Littmann, Wolfgang


    The article describes the correlation between capillary pressure and relative permeability in porous rocks. The Darcy equation for single phase flow and the physics of capillary pressure are shortly described using the concept of the hydraulic radius. Separating two phase flow in a porous medium into a Darcy component and into a capillary pressure component leads to an equation for the relative permabilities. Examples are given for relative permeabilities in surfactant flooding, the change in wettability and dependence of relative permeabilities on pressure or flow velocity. (orig.)

  15. A New Method to Identify Reservoirs in Tight Sandstones Based on the New Model of Transverse Relaxation Time and Relative Permeability

    Directory of Open Access Journals (Sweden)

    Yuhang Guo


    Full Text Available Relative permeability and transverse relaxation time are both important physical parameters of rock physics. In this paper, a new transformation model between the transverse relaxation time and the wetting phase’s relative permeability is established. The data shows that the cores in the northwest of China have continuous fractal dimension characteristics, and great differences existed in the different pore size scales. Therefore, a piece-wise method is used to calculate the fractal dimension in our transformation model. The transformation results are found to be quite consistent with the relative permeability curve of the laboratory measurements. Based on this new model, we put forward a new method to identify reservoir in tight sandstone reservoir. We focus on the Well M in the northwestern China. Nuclear magnetic resonance (NMR logging is used to obtain the point-by-point relative permeability curve. In addition, we identify the gas and water layers based on new T2-Kr model and the results showed our new method is feasible. In the case of the price of crude oil being low, this method can save time and reduce the cost.

  16. Effects of in-situ conditions on relative permeability characteristics of CO2-brine systems (United States)

    Bachu, Stefan; Bennion, Brant


    Carbon dioxide capture and geological storage (CCGS) is an emerging technology that is increasingly being considered for reducing greenhouse gas emissions to the atmosphere. Deep saline aquifers provide a very large capacity for CO2 storage and, unlike hydrocarbon reservoirs and coal beds, are immediately accessible and are found in all sedimentary basins. Proper understanding of the displacement character of CO2-brine systems at in-situ conditions is essential in ascertaining CO2 injectivity, migration and trapping in the pore space as a residual gas or supercritical fluid, and in assessing the suitability and safety of prospective CO2 storage sites. Because of lack of published data, the authors conducted a program of measuring the relative permeability and other displacement characteristics of CO2-brine systems for sandstone, carbonate and shale formations in central Alberta in western Canada. The tested formations are representative of the in-situ characteristics of deep saline aquifers in compacted on-shore North American sedimentary basins. The results show that the capillary pressure, interfacial tension, relative permeability and other displacements characteristics of CO2-brine systems depend on the in-situ conditions of pressure, temperature and water salinity, and on the pore size distribution of the sedimentary rock. This paper presents a synthesis and interpretation of the results.

  17. Process, mechanism and impacts of scale formation in alkaline flooding by a variable porosity and permeability model (United States)

    Zhang, Zhen; Li, Jiachun


    In spite of the role of alkali in enhancing oil recovery (EOR), the formation of precipitation during alkaline-surfactant-polymer (ASP) flooding can severely do harm to the stratum of oil reservoirs, which has been observed in situ tests of oil fields such as scale deposits found in oil stratum and at the bottom of oil wells. On the other hand, remarkable variation of stratum parameters, e.g., pore radius, porosity, and permeability due to scale formation considerably affects seepage flow and alkaline flooding process in return. The objective of this study is to firstly examine these mutual influential phenomena and corresponding mechanisms along with EOR during alkaline flooding when the effects of precipitation are no longer negligible. The chemical kinetic theory is applied for the specific fundamental reactions to describe the process of rock dissolution in silica-based reservoirs. The solubility product principle is used to analyze the mechanism of alkali scale formation in flooding. Then a 3D alkaline flooding coupling model accounting for the variation of porosity and permeability is established to quantitatively estimate the impact of alkali scales on reservoir stratum. The reliability of the present model is verified in comparison with indoor experiments and field tests of the Daqing oil field. Then, the numerical simulations on a 1/4 well group in a 5-spot pattern show that the precipitation grows with alkali concentration, temperature, and injection pressure and, thus, reduces reservoir permeability and oil recovery correspondingly. As a result, the selection of alkali with a weak base is preferable in ASP flooding by tradeoff strategy.

  18. Dynamic permeability and quantitative susceptibility: related imaging biomarkers in cerebral cavernous malformations. (United States)

    Mikati, Abdul Ghani; Tan, Huan; Shenkar, Robert; Li, Luying; Zhang, Lingjiao; Guo, Xiaodong; Larsson, Henrik B W; Shi, Changbin; Liu, Tian; Wang, Yi; Shah, Akash; Edelman, Robert R; Christoforidis, Gregory; Awad, Issam


    Hyperpermeability and iron deposition are 2 central pathophysiological phenomena in human cerebral cavernous malformation (CCM) disease. Here, we used 2 novel MRI techniques to establish a relationship between these phenomena. Subjects with CCM disease (4 sporadic and 17 familial) underwent MRI imaging using the dynamic contrast-enhanced quantitative perfusion and quantitative susceptibility mapping techniques that measure hemodynamic factors of vessel leak and iron deposition, respectively, previously demonstrated in CCM disease. Regions of interest encompassing the CCM lesions were analyzed using these techniques. Susceptibility measured by quantitative susceptibility mapping was positively correlated with permeability of lesions measured using dynamic contrast-enhanced quantitative perfusion (r=0.49; P≤0.0001). The correlation was not affected by factors, including lesion volume, contrast agent, and the use of statin medication. Susceptibility was correlated with lesional blood volume (r=0.4; P=0.0001) but not with lesional blood flow. The correlation between quantitative susceptibility mapping and dynamic contrast-enhanced quantitative perfusion suggests that the phenomena of permeability and iron deposition are related in CCM; hence, more leaky lesions also manifest a more cumulative iron burden. These techniques might be used as biomarkers to monitor the course of this disease and the effect of therapy.

  19. Breaking down the barriers: the gut microbiome, intestinal permeability and stress-related psychiatric disorders (United States)

    Kelly, John R.; Kennedy, Paul J.; Cryan, John F.; Dinan, Timothy G.; Clarke, Gerard; Hyland, Niall P.


    The emerging links between our gut microbiome and the central nervous system (CNS) are regarded as a paradigm shift in neuroscience with possible implications for not only understanding the pathophysiology of stress-related psychiatric disorders, but also their treatment. Thus the gut microbiome and its influence on host barrier function is positioned to be a critical node within the brain-gut axis. Mounting preclinical evidence broadly suggests that the gut microbiota can modulate brain development, function and behavior by immune, endocrine and neural pathways of the brain-gut-microbiota axis. Detailed mechanistic insights explaining these specific interactions are currently underdeveloped. However, the concept that a “leaky gut” may facilitate communication between the microbiota and these key signaling pathways has gained traction. Deficits in intestinal permeability may underpin the chronic low-grade inflammation observed in disorders such as depression and the gut microbiome plays a critical role in regulating intestinal permeability. In this review we will discuss the possible role played by the gut microbiota in maintaining intestinal barrier function and the CNS consequences when it becomes disrupted. We will draw on both clinical and preclinical evidence to support this concept as well as the key features of the gut microbiota which are necessary for normal intestinal barrier function. PMID:26528128

  20. Pore Structure and Diagenetic Controls on Relative Permeability: Implications for Enhanced Oil Recovery and CO2 Storage (United States)

    Feldman, J.; Dewers, T. A.; Heath, J. E.; Cather, M.; Mozley, P.


    Multiphase flow in clay-bearing sandstones of the Morrow Sandstone governs the efficiency of CO2 storage and enhanced oil recovery at the Farnsworth Unit, Texas. This formation is the target for enhanced oil recovery and injection of one million metric ton of anthropogenically-sourced CO2. The sandstone hosts eight major flow units that exhibit distinct microstructural characteristics due to diagenesis, including: "clean" macro-porosity; quartz overgrowths constricting some pores; ghost grains; intergranular porosity filled by microporous authigenic clay; and feldspar dissolution. We examine the microstructural controls on macroscale (core scale) relative permeability and capillary pressure behavior through: X-ray computed tomography, Robomet.3d, and focused ion beam-scanning electron microscopy imaging of the pore structure of the major flow units of the Morrow Sandstone; relative permeability and capillary pressure in the laboratory using CO2, brine, and oil at reservoir pressure and effective stress conditions. The combined data sets inform links between patterns of diagenesis and multiphase flow. These data support multiphase reservoir simulation and performance assessment by the Southwest Regional Partnership on Carbon Sequestration (SWP). Funding for this project is provided by the U.S. Department of Energy's National Energy Technology Laboratory through the SWP under Award No. DE-FC26-05NT42591. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  1. Pore-Scale Simulations Of Flow And Heat Transport In Saturated Permeable Media (United States)

    Zegers, G. R., Sr.; Herrera, P. A.


    The study of heat transport in porous media is important for applications such as the use of temperature as environmental tracer, geothermal energy, fuel cells, etc. In recent years, there have been several advances in computational techniques that have allowed to investigate different processes in porous media at the pore-scale through detailed numerical simulations that considered synthetic porous media formed by regular grains and pore bodies arranged in different geometrical configurations. The main objective of this research is to investigate the influence of pore configurations on flow velocity and heat transport in 2D saturated porous media. We use OpenFOAM to solve flow and heat transport equations at the pore-scale. We performed detailed pore-scale numerical simulations in synthetic 2D porous media generated from regularly placed and randomly distributed circular solid grains. For each geometrical configuration we performed numerical simulations to compute the flow field in order to calculate properties such as as tortuosity, mean velocity and hydraulic conductivity, and to identify Lagrangian coherent structures to charaterize the velocity fields. We then perform heat transport simulations to relate the properties of the velocity fields and the main heat transport mechanisms. The analysis of the simulations results showed that in all the simulated configurations effective flow properties become valid at scales of 10 to 15 pore bodies. For the same porosity and boundary conditions we obtained that as expected tortuosity in the random structure is higher than in the regular configurations, while hydraulic conductivity is smaller for the random case. The results of heat transport simulations show significant differences in temperature distribution for the regular and random pore structures. For the simulated boundary and initial conditions, heat transport is more efficient in the random structure than in the regular geometry. This result indicates that the

  2. Sensitivity Analysis of Interfacial Tension on Saturation and Relative Permeability Model Predictions

    KAUST Repository

    Abdallah, Wael


    Interfacial tension (IFT) measurements of Dodecane/brine systems at different concentrations and Dodecane/deionized water subject to different Dodecane purification cycles were taken over extended durations at room temperature and pressure to investigate the impact of aging. When a fresh droplet was formed, a sharp drop in IFT was observed assumed to be a result of intrinsic impurity adsorption at the interface. The subsequent measurements exhibited a prolonged equilibration period consistent with diffusion from the bulk phase to the interface. Our results indicate that minute amounts of impurities present in experimental chemical fluids "used as received" have a drastic impact on the properties of the interface. Initial and equilibrium IFT are shown to be dramatically different, therefore it is important to be cautious of utilizing IFT values in numerical models. The study demonstrates the impact these variations in IFT have on relative permeability relationships by adopting a simple pore network model simulation.

  3. 2D dual permeability modeling of flow and transport in a two-scale structured lignitic mine soil (United States)

    Dusek, J.; Gerke, H. H.; Vogel, T.; Maurer, T.; Buczko, U.


    Two-dimensional single- and dual-permeability simulations are used to analyze water and solute fluxes in heterogeneous lignitic mine soil at a forest-reclaimed mine spoil heap. The soil heterogeneity on this experimental site "Bärenbrücker Höhe" resulted from inclined dumping structures and sediment mixtures that consist of sand with lignitic dust and embedded lignitic fragments. Observations on undisturbed field suction-cell lysimeters including tracer experiments revealed funneling-type preferential flow with lateral water and bromide movement along inclined sediment structures. The spatial distribution of soil structures and fragment distributions was acquired by a digital camera and identified by a supervised classification of the digital profile image. First, a classical single-domain modeling approach was used, with spatially variable scaling factors inferred from image analyses. In the next step, a two-continuum scenario was constructed to examine additional effects of nonequilibrium on the flow regime. The scaling factors used for the preferential flow domain are here obtained from the gradient of the grayscale images. So far, the single domain scenarios failed to predict the bromide leaching patterns although water effluent could be described. Dual-permeability model allows the incorporation of structural effects and can be used as a tool to further testing other approaches that account for structure effects. The numerical study suggests that additional experiments are required to obtain better understanding of the highly complex transport processes on this experimental site.

  4. Exogenous collagen cross-linking reduces scleral permeability: modeling the effects of age-related cross-link accumulation. (United States)

    Stewart, Jay M; Schultz, David S; Lee, On-Tat; Trinidad, Monique L


    To investigate the relationship between scleral permeability and nonenzymatic cross-link density. Scleral discs 18 mm in diameter were dissected from the medial and lateral equatorial regions of 60 cadaveric porcine eyes. Samples were incubated for 24 hours with control solution or methylglyoxal at concentrations of 0.001%, 0.01%, 0.10%, and 1.00%. Nonenzymatic cross-link density in treated and control groups was quantified with the use of papain digest and fluorescence spectrophotometry. Treated scleral discs were mounted in a customized Ussing-type chamber connected to vertical tubing, and specific hydraulic conductivity was determined according to the descent of a column of degassed saline at room temperature. Permeability to diffusion of fluorescein in a static chamber was determined for another set of treated scleral samples. Methylglyoxal treatment effectively increased nonenzymatic cross-link content, as indicated by the average fluorescence for each group. Specific hydraulic conductivity (m(2)) was reduced with increasing cross-link density. Similarly, the permeability coefficient for the fluorescein solute consistently decreased with increasing methylglyoxal concentration, indicating diffusion impedance from the treatment. Nonenzymatic cross-link density can be significantly increased by treatment with methylglyoxal. Porcine sclera showed a nonlinear reduction in solute permeability and specific hydraulic conductivity with increasing cross-link density. This model indicates that age-related nonenzymatic cross-link accumulation can have a substantial impact on scleral permeability.

  5. Permeable reactive barriers for the remediation of groundwater in a mining area: results for a pilot-scale project (United States)

    Martinez-Sanchez, Maria Jose; Perez-Sirvent, Carmen; Garcia-Lorenzo, Maria Luz; Martinez-Lopez, Salvadora; Perez-Espinosa, Victor; Gonzalez-Ciudad, Eva; Belen Martinez-Martinez, Lucia; Hernandez, Carmen; Molina-Ruiz, Jose


    The Sierra Minera of Cartagena-La Union is located in the Region of Murcia, Southeast of Spain. This zone presents high levels of heavy metals due to natural, geogenic reasons. In addition, the prolonged mining activity, and subsequent abandonment of farms, has had consequences on the environment, including severe affectation of the groundwater in the area. To remediate this situation, the Permeable Reactive Barrier (PRB) technology was assayed, which required in addition to the hydro-geological study of the zone, a careful optimization study for the design and construction of PRBs. For such a purpose a pilot-scale project was developed, and this communication reports some of the most relevant findings obtained after a four-years monitorization period. The selected reactive material for the PRBs was limestone filler. The filler is a waste material produced in many factories in the zone. These residues have good adsorption properties, high alkalinity, low cost and high availability, which make them suitable for use in remediation. The PRB was constituted by a 50% limestone filler and 50% sand, a proportion optimized by means of independent batch experiments. A layer of gravel was placed at the top, and on it a layer of natural soil. The barrier was designed in the form of a continuous trench, because the level of the contaminated groundwater was not very deep. In this way, the barrier could be prepared with standard excavation equipment. Parallel to the barrier, 6 wells where arranged downstream for sample collection. The pH and conductivity of the samples was measured directly in situ, and the content of Zn, Cd, Cu, Fe, and Pb were analyzed in the laboratory. All the samples collected after the PRB was constructed had basic pH values between 7.5 and 8. The conductivity was between 5 and 11 mS / cm except for the well 4, which had a value of 3.70 mS / cm. The concentration values of trace elements were below the detection limit (atomic absorption measurement) in

  6. The hydrogen permeability of Pd-Cu based thin film membranes in relation to their structure : A combinatorial approach

    NARCIS (Netherlands)

    Westerwaal, R. J.; Bouman, E. A.; Haije, W. G.; Schreuders, H.; Dutta, S.; Wu, M. Y.; Boelsma, C.; Ngene, P.; Basak, S.; Dam, B.


    Pd-Cu is a well-known alloy for H-2 separation membranes. Using a new optical combinatorial method we determined the H-2 permeability of Pd-Cu alloys at room temperature in relation to their crystal structure and microstructure. Compositional gradient samples allow us to determine the intrinsic

  7. Evaluation of different toxicity assays applied to proliferating cells and to stratified epithelium in relation to permeability enhancement with glycocholate

    DEFF Research Database (Denmark)

    Eirheim, Heidi Ugelstad; Bundgaard, Christoffer; Nielsen, Hanne Mørck


    exposed to different GC concentrations for 4 h. The MTS/PMS assay and neutral red (NR) retention were performed along with quantitation of ATP, lactate dehydrogenase (LDH) and extracellular protein. The toxicity was calculated as the IC50 value relative to the control. Increase in 3H-mannitol permeability...

  8. Experimental Investigation of Relative Permeability Upscaling from the Micro-Scale to the Macro-Scale

    Energy Technology Data Exchange (ETDEWEB)

    Pyrak-Nolte, Laura J.; Cheng, JiangTao; Yu, Ping; Giordano, Nicholas; Mustata, Mirela; Chen, Diaquam; Coy, John; Cooper, Nathan; Nolte, David D.


    During this reporting period, shown experimentally that the optical coherence imaging system can acquire information on grain interfaces and void shape for a maximum depth of half a millimeter into sandstone. The measurement of interfacial area per volume (IAV), capillary pressure and saturation in two dimensional micro-models structures has shown the existence of a unique relationship among these hydraulic parameters for different pore geometry. The measurement of interfacial area per volume on a three-dimensional natural sample, i.e., sandstone, has shown the homogeneity of IAV with depth in a sample when the fluids are in equilibrium.

  9. Anisotropy and spatial variation of relative permeability and lithologic character of Tensleep Sandstone reservoirs in the Bighorn and Wind River Basins, Wyoming. Annual report, October 1, 1994-- September 30, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, T.L.


    This research is to provide improved strategies for enhanced oil recovery from the Tensleep Sandstone oil reservoirs in the Bighorn and Wind River basins, Wyoming. Because of the great range of API gravities of the oils produced from these reservoirs, the proposed study concentrates on understanding the spatial variation and anisotropy of relative permeability within the Tensleep Sandstone. This research will associate those spatial distributions and anisotropies with the depositional subfacies and zones of diagenetic alteration found within the sandstone. The associations of the above with pore geometry will link relative permeability with the dimensions of lithofacies and authigenic mineral facies. Hence, the study is to provide criteria for scaling this parameter on a range of scales, from the laboratory to the basin-wide scale of subfacies distribution. Effects of depositional processes and burial diagenesis will be investigated. Image analysis of pore systems will be done to produce algorithms for estimating relative permeability from petrographic analyses of core and well cuttings. In addition, these studies are being coupled with geochemical modeling and coreflood experiments to investigate the potential for wellbore scaling and formation damage anticipated during EOR, eg., CO{sub 2} flooding. This will provide a regional basis for EOR strategies for the largest potential target reservoir in Wyoming; results will have application to all eolian reservoirs through correlations of relative permeability variation and anisotropy with eolian depositional lithofacies.

  10. Relative permeability of coal to gas (Helium, Methane and Carbon dioxide) and water - Results and experimental limitations

    Energy Technology Data Exchange (ETDEWEB)

    Ham, Y.S.; Kantzas, A. [University of Calgary (Canada)


    Coalbed methane reservoir exploitation is gaining more and more importance as an economically viable, yet unconventional, gas source. An important aspect of such exploitation is the possibility of assessing the production of a given reservoir; knowledge of coal's petrochemical properties is thus a crucial point in the development of the coalbed gas industry. This paper focuses on experimental procedures for determining the two-phase, gas-water relative permeability of coal, using 2 coal samples extracted from Canadian mines. The experiments were done using an unsteady-state relative permeability procedure, involving drainage and imbibition of coal samples by mixture of water and helium, methane and carbon dioxide. Derivations are also given to ascertain relative permeability from experimental data. Despite experimental difficulties regarding reproducibility, due to degradation of the coal samples, results showed that coal permeability depends strongly on the adsorption properties of gases, coal becoming more water-wet for adsorbable gases, methane and carbon dioxide, whereas influx of water in larger pores induced a lesser water saturation with helium.

  11. Hydrothermal alteration and permeability changes in granitic intrusions related to Sn-W deposits : case study of Panasqueira (Portugal) (United States)

    Launay, Gaetan; Sizaret, Stanislas; Guillou-Frottier, Laurent; Gloaguen, Eric; Melleton, Jérémie; Pichavant, Michel; Champallier, Rémi; Pinto, Filipe


    The Panasqueira Sn-W deposit occurs as a dense network of flat wolframite and cassiterite-bearing quartz veins concentrated in the vicinity of a hidden greisen cupola, and to a lesser extent as disseminated cassiterites in the greisen. Previous studies (Thadeu 1951; 1979) have suggested that the Panasqueira deposit is genetically related to magmatic activity for which the most part is unexposed, and being only represented by the greisen cupola. Hydrothermal fluid circulation during the final stages of granite crystallisation has probably led to the greisenisation of the cupola followed by the deposition of the mineralization in the veins system. Mineral replacement reactions that occurred during the greisenisation could affect rock properties (porosity, density and permeability) which control fluid circulation in the granite. This study aims to investigate effects of greisenisation reactions on the dynamic (time varying) permeability that ultimately leads to fluid circulation in the greisen cupola. To do so, petrological study and experimental determinations of hydrodynamic features (porosity and permeability) for different granite alteration levels and petrographic types (unaltered granite to greisen) are combined and then integrated in coupled numerical models of fluid circulation around the granitic intrusion. Greisen occurs in the apical part of the granitic body and results in the pervasive alteration of the granite along the granite-schist contact. This greisen consists mainly of quartz and muscovite formed by the replacement of feldspars and bleaching of biotites of the initial granite. Otherwise, greisen is generally vuggy which suggests a porosity increase of the granite during hydrothermal alteration processes. This porosity increase has a positive effect on the permeability of the granitic system. Indeed, experimental measurements of permeability with the Paterson press indicate that the initial granite is impermeable (10-20 m2) whereas the greisen is

  12. Transfusion-related acute lung injury: critical neutrophil activation by anti-HLA-A2 antibodies for endothelial permeability. (United States)

    Khoy, Kathy; Nguyen, Minh Vu Chuong; Masson, Dominique; Bardy, Béatrice; Drouet, Christian; Paclet, Marie-Hélène


    Transfusion-related acute lung injury (TRALI) is a major complication of hemotherapy that may occur after the transfusion of any blood type component. Several clinical reports have suggested the presence of anti-HLA antibodies in the blood product. This study sought to examine the role of anti-HLA-A2 antibodies in polymorphonuclear neutrophil (PMN) activation and thus in endothelial permeability. PMN activation was assessed by both nicotinamide adenine dinucleotide phosphate oxidase (NADPH oxidase) activity and reactive oxygen species (ROS) production. A coculture assay of EA.hy926 endothelial cells with PMNs or differentiated-PLB-985 cells, a model of neutrophil-like cells, was performed to estimate the impact of ROS on endothelial permeability. Anti-HLA-A2 antibodies significantly increased PMN activation, with subsequent endothelial dysfunction. Phagocyte NADPH oxidase (NOX2) activity was shown to be involved in this process and ROS themselves were demonstrated to induce VE-cadherin cleavage and endothelial permeability. Our data may support the existence of a critical anti-HLA-A2 antibody threshold for PMN activation, with NOX2 activity and subsequent endothelial permeability in the two-hit model of TRALI. © 2017 AABB.

  13. Testing Asteroseismic Scaling Relations with Interferometry

    Directory of Open Access Journals (Sweden)

    White T. R.


    Full Text Available The asteroseismic scaling relations for the frequency of maximum oscillation power, vmax, and the large frequency separation, Δν, provide an easy way to directly determine the masses and radii of stars with detected solar-like oscillations. With the vast amount of data available from the CoRoT and Kepler missions, the convenience of the scaling relations has resulted in their wide-spread use. But how valid are the scaling relations when applied to red giants, which have a substantially different structure than the Sun? Verifying the scaling relations empirically requires independent measurements. We report on the current state and future prospects of interferometric tests of the scaling relations.

  14. Effect of curcumin on permeability of coronary artery and expression of related proteins in rat coronary atherosclerosis heart disease model. (United States)

    Li, Xiaolong; Lu, Yan; Sun, Yi; Zhang, Qi


    Our objective is to explore the effect of curcumin on permeability of coronary artery and expression of related proteins in rat coronary atherosclerosis heart disease model. 45 healthy male Wistar rats of clean grade were selected and divided into treatment group, model control group and blank control group. The rats in the treatment group and model control group received high-fat diet for 12 weeks and intraperitoneal injection of VD3 to establish rat coronary atherosclerosis heart disease model. After modeling, the rats in the treatment group received gavage of 100 mg/(kg·d) curcimin, and the rats in the model control group and blank control group received gavage of 5 ml/(kg·d) distilled water, the intervention time was 4 weeks. After intervention, the rats were killed, and the hearts were dissected to obtain the samples of coronary artery. After embedding and frozen section, immunofluorescence method was used to detect the change of endarterium permeability in 3 groups, Western blot was used to detect matrix metalloproteinase-9 (MMP-9) and CD40L in coronary artery tissue, and enzyme linked immunosorbent assay (ELISA) was used to detect serum tumor necrosis factor-α (TNF-α) and C reaction protein (CRP). After modeling, compared with the blank control group, total cholesterol (TC), triglyceride (TG) and low density lipoprotein cholesterin (LDL-c) in the treatment group and model control group were significantly higher (Pcoronary artery in treatment group and model control group, indicating that the modeling was successful. Immunofluorescence showed that there was only a little fluorochrome permeability in artery in blank control group, there was some fluorochrome permeability in artery in the treatment group and there was a lot of fluorochrome permeability in artery in the model control group. MMP-9 and CD40L in coronary artery tissue in the model control group were significantly higher than the treatment group (Pcoronary artery tissue in the treatment group


    NARCIS (Netherlands)

    van Elburg, R. M.; Uil, J. J.; Mulder, C. J.; Heymans, H. S.


    The functional integrity of the small bowel is impaired in coeliac disease. Intestinal permeability, as measured by the sugar absorption test probably reflects this phenomenon. In the sugar absorption test a solution of lactulose and mannitol was given to the fasting patient and the


    NARCIS (Netherlands)


    The functional integrity of the small bowel is impaired in coeliac disease. Intestinal permeability, as measured by the sugar absorption test probably reflects this phenomenon. In the sugar absorption test a solution of lactulose and mannitol was given to the fasting patient and the

  17. Scaling of permeabilities and friction factors of homogeneously expanding gas-solids fluidized beds: Geldart’s A powders and magnetically stabilized beds

    Directory of Open Access Journals (Sweden)

    Hristov Jordan Y.


    Full Text Available The concept of a variable friction factor of fluid-driven de form able powder beds undergoing fluidization is discussed. The special problem discussed addresses the friction factor and bed permeability relationships of Geldart’s A powders and magnetically stabilized beds in axial fields. Governing equations and scaling relation ships are developed through three approaches (1 Minimization of the pressure drop with respect to the fluid velocity employing the Darcy-Forchheimer equation together with the Richardson-Zaki scaling law, (2 Minimization of the pres sure drop across an equivalent-channel replacing the actual packed beds by a straight pipe with bed-equivalent obstacle of a simple geometry, and (3 Entropy minimization method applied in cases of the Darcy-Forchheimer equation and the equivalent-channel model. Bed-to-surface heat transfer coefficients are commented in the context of the porosity/length scale relationships developed. Both the pressure drop curves developments and phase diagram de signs are illustrated by applications of the intersection of asymptotes technique to beds exhibiting certain degree of cohesion.

  18. Literature review and recommendation of methods for measuring relative permeability of anhydrite from the Salado Formation at the Waste Isolation Pilot Plant

    Energy Technology Data Exchange (ETDEWEB)

    Christiansen, R.L. [Colorado School of Mines, Golden, CO (United States). Dept. of Petroleum Engineering; Howarth, S.M. [Sandia National Labs., Albuquerque, NM (United States)


    This report documents a literature review of methods for measuring relative permeability as applied to low permeability anhydrite rock samples from the Salado Formation. About one hundred papers were reviewed, and four methods were identified as promising techniques for measuring the relative permeability of the Salado anhydrite: (1) the unsteady-state high-rate method, (2) the unsteady-state stationary-liquid method, (3) the unsteady-state centrifuge method, and (4) the unsteady-state low-rate method. Except for the centrifuge method, all have been used for low permeability rocks. The unsteady-state high-rate method is preferred for measuring relative permeability of Salado anhydrite, and the unsteady-state stationary-liquid method could be well suited for measuring gas relative permeability of Salado anhydrite. The unsteady-state low-rate method, which combines capillary pressure effects with relative permeability concepts may also prove effective. Likewise, the unsteady-state centrifuge method may be an efficient means for measuring brine relative permeability for Salado anhydrite, especially at high gas saturations.

  19. Evaluation of gas condensate reservoir behavior using velocity dependent relative permeability during the numerical well test analysis

    Directory of Open Access Journals (Sweden)

    Arash Azamifard


    Full Text Available Gas condensate is one of the most different fluids in reservoir simulation due to retrograde condensation in case of pressure reduction. In this kind of fluids, two phenomena named negative inertia and positive coupling, become significant in the high velocity zone around the wellbore. In this study, a modified black oil simulator is developed that take into account the velocity dependent relative permeability. Against the industrial simulator that assumes linear variation of transmissibilities by pressure, modified black oil nonlinear equations are solved directly without linearization. The developed code is validated by ECLIPSE simulator. The behavior of two real gas condensate fluids, a lean and a rich one, are compared with each other. For each fluid, simulations of PVT experiments are carried out to calculate black oil property applying Coats approach for gas condensate fluids. For both fluids, the proposed models for gas condensate velocity dependent relative permeability show different influence of velocity on relative permeability in the same conditions. Moreover, it is observed that higher flow rate of gas production leads to more condensate production during constant rate well testing.

  20. Further Validation of the Relational Ethics Scale. (United States)

    Hargrave, Terry D.; Bomba, Anne K.


    Conducted two studies to examine effects of marital status and age on Relational Ethics Scale. Study One indicated that scale was reliable and valid among single, never married young adults (n=162). Study Two examined differences between scores for this population and original normative sample. Findings suggest that ethical issues with…

  1. A study of relative permeability parameters on rock cores using a two-phase flow test


    Chung-Hui Chiao; Chi-Wen Yu; Shih-Chang Lei; Jyun-Yu Lin; Chia-Yu Lu


    To ensure sequestration safety, confirming the injectivity of the reservoir rock formation is of critical importance, requiring studies of the rock permeability to uncover the fluid migration scenarios within the porous reservoir rock. Two-phase (super-critical CO2-brine) flow behavior following the post CO2 injection is believed to be a dominating factor; its flooding behavior within the porous rock media needs to be further clarified prior to confirming the feasibility of domestic CO2 geo-s...

  2. A Study of the Effect of Relative Permeability and Residual Oil Saturation on Oil Recovery


    Ediriweera, Mahesh Priyankara; Halvorsen, Britt


    The depletion of oil production and the low recovery rate are the major challenges faced in oil production. Several studies have shown that considerable amount of oil still remains in the reservoir after the well shutdown. Heavy oil reservoirs occupy more than two third of globally oil reserves. The recovery factor and the lifetime of a well in heavy oil reservoirs is strongly affected by reservoir properties as permeability and porosity, residual oil saturation and the time of water breakthr...

  3. Permeable Reactive Biobarriers for In Situ Cr(VI) Reduction: Bench Scale Tests Using Cellulomonas sp. Strain ES6

    Energy Technology Data Exchange (ETDEWEB)

    Sridhar Viamajala; Brent M. Peyton; Robin Gerlach; Vaideeswaran; William A. Apel; James N. Petersen


    Chromate (Cr(VI)) reduction studies were performed in bench scale flow columns using the fermentative subsurface isolate Cellulomonas sp. strain ES6. In these tests, columns packed with either quartz sand or hydrous ferric oxide (HFO)-coated quartz sand, were inoculated with strain ES6 and fed nutrients to stimulate growth before nutrient-free Cr(VI) solutions were injected. Results show that in columns containing quartz sand, a continuous inflow of 2 mg/L Cr(VI) was reduced to below detection limits in the effluent for durations of up to 5.7 residence times after nutrient injection was discontinued proving the ability of strain ES6 to reduce chromate in the absence of an external electron donor. In the HFO-containing columns, Cr(VI) reduction was significantly prolonged and effluent Cr(VI) concentrations remained below detectable levels for periods of up to 66 residence times after nutrient injection was discontinued. Fe was detected in the effluent of the HFO-containing columns throughout the period of Cr(VI) removal indicating that the insoluble Fe(III) bearing solids were being continuously reduced to form soluble Fe(II) resulting in prolonged abiotic Cr(VI) reduction. Thus, growth of Cellulomonas within the soil columns resulted in formation of permeable reactive barriers that could reduce Cr(VI) and Fe(III) for extended periods even in the absence of external electron donors. Other bioremediation systems employing Fe(II)-mediated reactions require a continuous presence of external nutrients to regenerate Fe(II). After depletion of nutrients, contaminant removal within these systems occurs by reaction with surface-associated Fe(II) that can rapidly become inaccessible due to formation of crystalline Fe-minerals or other precipitates. The ability of fermentative organisms like Cellulomonas to reduce metals without continuous nutrient supply in the subsurface offers a viable and economical alternative technology for in situ remediation of Cr

  4. Permeable reactive biobarriers for in situ Cr(VI) reduction: bench scale tests using Cellulomonas sp. strain ES6. (United States)

    Viamajala, Sridhar; Peyton, Brent M; Gerlach, Robin; Sivaswamy, Vaideeswaran; Apel, William A; Petersen, James N


    Chromate (Cr(VI)) reduction studies were performed in bench scale flow columns using the fermentative subsurface isolate Cellulomonas sp. strain ES6. In these tests, columns packed with either quartz sand or hydrous ferric oxide (HFO)-coated quartz sand, were inoculated with strain ES6 and fed nutrients to stimulate growth before nutrient-free Cr(VI) solutions were injected. Results show that in columns containing quartz sand, a continuous inflow of 2 mg/L Cr(VI) was reduced to below detection limits in the effluent for durations of up to 5.7 residence times after nutrient injection was discontinued proving the ability of strain ES6 to reduce chromate in the absence of an external electron donor. In the HFO-containing columns, Cr(VI) reduction was significantly prolonged and effluent Cr(VI) concentrations remained below detectable levels for periods of up to 66 residence times after nutrient injection was discontinued. Fe was detected in the effluent of the HFO-containing columns throughout the period of Cr(VI) removal indicating that the insoluble Fe(III) bearing solids were being continuously reduced to form soluble Fe(II) resulting in prolonged abiotic Cr(VI) reduction. Thus, growth of Cellulomonas within the soil columns resulted in formation of permeable reactive barriers that could reduce Cr(VI) and Fe(III) for extended periods even in the absence of external electron donors. Other bioremediation systems employing Fe(II)-mediated reactions require a continuous presence of external nutrients to regenerate Fe(II). After depletion of nutrients, contaminant removal within these systems occurs by reaction with surface-associated Fe(II) that can rapidly become inaccessible due to formation of crystalline Fe-minerals or other precipitates. The ability of fermentative organisms like Cellulomonas to reduce metals without continuous nutrient supply in the subsurface offers a viable and economical alternative technology for in situ remediation of Cr

  5. Modified dispersion relations, inflation, and scale invariance (United States)

    Bianco, Stefano; Friedhoff, Victor Nicolai; Wilson-Ewing, Edward


    For a certain type of modified dispersion relations, the vacuum quantum state for very short wavelength cosmological perturbations is scale-invariant and it has been suggested that this may be the source of the scale-invariance observed in the temperature anisotropies in the cosmic microwave background. We point out that for this scenario to be possible, it is necessary to redshift these short wavelength modes to cosmological scales in such a way that the scale-invariance is not lost. This requires nontrivial background dynamics before the onset of standard radiation-dominated cosmology; we demonstrate that one possible solution is inflation with a sufficiently large Hubble rate, for this slow roll is not necessary. In addition, we also show that if the slow-roll condition is added to inflation with a large Hubble rate, then for any power law modified dispersion relation quantum vacuum fluctuations become nearly scale-invariant when they exit the Hubble radius.

  6. The permeability of heterogeneous rocks (United States)

    Selvadurai, Patrick


    Darcy's original concept of permeability is largely associated with estimation of the hydraulic conductivity characteristics of isotropic and homogeneous porous media where the fluid flow characteristics can be estimated by appeal to a single scalar measure. Naturally occurring geomaterials are heterogeneous and the estimation of the effective permeability characteristics of such geomaterials presents a challenge not only in terms of the experimental procedures that should be used to ensure flow through the porous medium but also in the correct use of the theoretical concepts needed to accurately interpret the data. Relatively widely referred to rocks such as Indiana Limestone can exhibit spatial heterogeneity in the permeability characteristics even though the visual appearance can suggest the absence of such spatial and directional attributes (Selvadurai and Selvadurai, 2010). Argillaceous rocks such as the Cobourg Limestone found in southern Ontario, Canada can display hydraulic heterogeneity that is attributed to the presence of dolomitic and calcite nodular regions separated by calcite rock partings that contain an argillaceous component (Figure 1). Also, these rocks have extremely low permeability that requires the use of transient hydraulic pulse tests for the estimation of permeability. The performance of such pulse tests will be influenced by the bulk compressibility and bulk porosity of the porous skeleton consisting of the identifiable phases and their spatial distributions. The concepts of effective compressibilities and porosities therefore needs to be introduced if convenient procedures are to be developed for the accurate interpretation of even bench scale experiments (Selvadurai and Gɫowacki, 2017). The paper will describe both experimental and theoretical approaches for interpreting the effective Darcy permeability of the heterogeneous rocks using both experimental and computational approaches. In particular, the applicability of the "Geometric

  7. Measurement of choroid plexus perfusion using dynamic susceptibility MR imaging: capillary permeability and age-related changes

    Energy Technology Data Exchange (ETDEWEB)

    Bouzerar, Roger; Chaarani, Bader; Baledent, Olivier [University Hospital, Image Processing Department, Amiens (France); Gondry-Jouet, Catherine [University Hospital, Radiology Department, Amiens (France); Zmudka, Jadwiga [University Hospital, Geriatric Unit, Amiens (France)


    The cerebrospinal fluid (CSF) plays a major role in the physiology of the central nervous system. The continuous turnover of CSF is mainly attributed to the highly vascularized choroid plexus (CP) located in the cerebral ventricles which represent a complex interface between blood and CSF. We propose a method for evaluating CP functionality in vivo using perfusion MR imaging and establish the age-related changes of associated parameters. Fifteen patients with small intracranial tumors were retrospectively studied. MR Imaging was performed on a 3T MR Scanner. Gradient-echo echo planar images were acquired after bolus injection of gadolinium-based contrast agent (CA). The software developed used the combined T1- and T2-effects. The decomposition of the relaxivity signals enables the calculation of the CP capillary permeability (K{sub 2}). The relative cerebral blood volume (rCBV), mean transit time (MTT), and signal slope decrease (SSD) were also calculated. The mean permeability K{sub 2} of the extracted CP was 0.033+/-0.18 s{sup -1}. K{sub 2} and SSD significantly decreased with subject's age whereas MTT significantly increased with subject's age. No significant correlation was found for age-related changes in rCBV and rCBF. The decrease in CP permeability is in line with the age-related changes in CSF secretion observed in animals. The MTT increase indicates significant structural changes corroborated by microscopy studies in animals or humans. Overall, DSC MR-perfusion enables an in vivo evaluation of the hemodynamic state of CP. Clinical applications such as neurodegenerative diseases could be considered thanks to specific functional studies of CP. (orig.)

  8. Crustal permeability (United States)

    Gleeson, Tom; Ingebritsen, Steven E.


    Permeability is the primary control on fluid flow in the Earth’s crust and is key to a surprisingly wide range of geological processes, because it controls the advection of heat and solutes and the generation of anomalous pore pressures.  The practical importance of permeability – and the potential for large, dynamic changes in permeability – is highlighted by ongoing issues associated with hydraulic fracturing for hydrocarbon production (“fracking”), enhanced geothermal systems, and geologic carbon sequestration.  Although there are thousands of research papers on crustal permeability, this is the first book-length treatment.  This book bridges the historical dichotomy between the hydrogeologic perspective of permeability as a static material property and the perspective of other Earth scientists who have long recognized permeability as a dynamic parameter that changes in response to tectonism, fluid production, and geochemical reactions. 

  9. Study of the permeability up-scaling by direct filtering of geostatistical model; Etude du changement d'echelle des permeabilites par filtrage direct du modele geostatistique

    Energy Technology Data Exchange (ETDEWEB)

    Zargar, G.


    In this thesis, we present a new approach, which consists in directly up-scaling the geostatistical permeability distribution rather than the individual realizations. Practically, filtering techniques based on. the FFT (Fast Fourier Transform), allows us to generate geostatistical images, which sample the up-scaled distributions. In the log normal case, an equivalence hydraulic criterion is proposed, allowing to re-estimate the geometric mean of the permeabilities. In the anisotropic case, the effective geometric mean becomes a tensor which depends on the level of filtering used and it can be calculated by a method of renormalisation. Then, the method was generalized for the categorial model. Numerical tests of the method were set up for isotropic, anisotropic and categorial models, which shows good agreement with theory. (author)

  10. Notional Permeability

    NARCIS (Netherlands)

    Kik, R.; Van den Bos, J.P.; Maertens, J.; Verhagen, H.J.; Van der Meer, J.W.


    Different layer design of a rock slope and under layers has a large effect on the strengths on the rock slope itself. In the stability formula developed of VAN DER MEER [1988] this effect is represented by the term Notional Permeability with symbol P. A more open, or permeable, structure underneath

  11. Basin-scale relations via conditioning (United States)

    Troutman, B.M.; Karlinger, M.R.; Guertin, D.P.


    A rainfall-runoff model is used in conjunction with a probabilistic description of the input to this model to obtain simple regression-like relations for basin runoff in terms of basin and storm characteristics. These relations, similar to those sought in regionalization studies, are computed by evaluating the conditional distribution of model output given basin and storm characteristics. This method of conditioning provides a general way of examining model sensitivity to various components of model input. The resulting relations may be expected to resemble corresponding relations obtained by regionalization using actual runoff to the extent that the rainfall-runoff model and the model input specification are physically realistic. The probabilistic description of model input is an extension of so-called "random-model" of channel networks and involves postulating an ensemble of basins and associated probability distributions that mimic the variability of basin characteristics seen in nature. Application is made to small basins in the State of Wyoming. Parameters of the input variable distribution are estimated using data from Wyoming, and basin-scale relations are estimated both, parametrically and nonparametrically using model-generated runoff from simulated basins. Resulting basin-scale relations involving annual flood quantiles are in reasonable agreement with those presented in a previous regionalization study, but error estimates are smaller than those in the previous study, an artifact of the simplicity of the rainfall-runoff model used in this paper. We also obtain relations for peak of the instantaneous unit hydrograph which agree fairly well with theoretical relations given in the literature. Finally, we explore the issues of sensitivity of basin-scale, relations and error estimates to parameterization of the model input probability distribution and of how this sensitivity is related to making inferences about a particular ungaged basin. ?? 1989 Springer-Verlag.

  12. Heritage and scale: settings, boundaries and relations

    DEFF Research Database (Denmark)

    Harvey, David


    of individuals and communities, towns and cities, regions, nations, continents or globally – becomes ever more important. Partly reflecting this crisis of the national container, researchers have sought opportunities both through processes of ‘downscaling’, towards community, family and even personal forms...... relations. This paper examines how heritage is produced and practised, consumed and experienced, managed and deployed at a variety of scales, exploring how notions of scale, territory and boundedness have a profound effect on the heritage process. Drawing on the work of Doreen Massey and others, the paper...

  13. Evaluating the Infiltration Performance of Eight Dutch Permeable Pavements Using a New Full-Scale Infiltration Testing Method

    NARCIS (Netherlands)

    Boogaard, F.C.; Lucke, T.; Van de Giesen, N.C.; Van de Ven, F.H.M.


    Permeable pavements are a type of sustainable urban drainage system (SUDS) technique that are used around the world to infiltrate and treat urban stormwater runoff and to minimize runoff volumes. Urban stormwater runoff contains significant concentrations of suspended sediments that can cause

  14. Investigating the H2O/O2 selective permeability from a view of multi-scale structure of starch/SiO2 nanocomposites. (United States)

    Liu, Siyuan; Li, Xiaoxi; Chen, Ling; Li, Lin; Li, Bing; Zhu, Jie; Liang, Xiaoyun


    In order to control H2O/O2 selective permeability of starch based nanocompsites for food packaging, the addition of SiO2 nanoparticles was proven to be an effective method. The results suggested that the SiO2/hydroxypropyl starch (HPS) ratio was a feasible approach to regulate the film multi-scale structure. The H2O/O2 selective permeability was influenced by comprehensive factors including film short-range molecular conformation, crystalline structure and aggregated structure. The increase of micro-ordered region size was likely to favor the improvement of water vapor barrier property and the rise of compactness in this region seems to contribute to the oxygen prevention. Notably, the effect of film multi-scale structure on H2O/O2 selective permeability could be a supplement to conventional "tortuous path" theory for the explanation of barrier property improvement. This study could significantly guide to the rational design of H2O/O2 selective biodegradable food packaging in order to meet the requirement for different food systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Fault Zone Architecture and Mineralogy: Implications in Fluid Flow and Permeability in Crustal Scale Fault Zones in the Southern Andes. (United States)

    Roquer, T.; Terrón, E.; Perez-Flores, P.; Arancibia, G.; Cembrano, J. M.


    Fluid flow in the upper crust is controlled by the permeability and interconnection of fractures in the fault zones. The permeability within the fault zone is determined by its activity, architecture and, in particular, by the mineralogy of the core and the damage zone. Whereas the permeability structure of a fault zone can be defined by the volume proportion of the core with respect to the damage zone, the relationship between the mineralogy and permeability along fault zones still remains obscure. This work examines structural and mineralogical data to show the relationship between the mineral composition of the fault zone with its permeability in the Liquiñe-Ofqui Fault System (LOFS) and the Arc-oblique Long-lived Fault Systems (ALFS), Southern Chile. The LOFS is an active ca. 1200 km long strike-slip Cenozoic intra-arc structure that strikes NNE in its master traces and NE in its subsidiary traces, with dextral and dextral-normal movement mostly developed in the last 6 My. Although the LOFS and the ALFS cross-cut each other, the ALFS is an apparently older basement fault system where seismic and field evidences record sinistral, sinistral-normal and sinistral-reverse movements. One 22-m-long NE transect was mapped orthogonal to a segment of the ALFS, where host rocks are Miocene andesitic rocks. Structural and XRD sampling were conducted in the core and damage zone. Structural mapping shows a multiple core, NW-striking fault zone with foliated gouge and an asymmetric damage zone, where the hanging wall has significantly higher mesoscopic fracture density than the footwall. The hanging wall is characterized by NW-striking, steeply dipping veins. Preliminary XRD results indicate the presence of homogenously distributed Ca-rich zeolite (mainly laumontite) in the core and the veins of the damage zone, which could indicate that the core acted as a conduit for low-temperature (ca. 220°C) fluids.

  16. Sensitivity Analysis and Parameter Identifiability of the Land Surface Model JULES at the point scale in permeable catchments (United States)

    Bakopoulou, C.; Bulygina, N.; Butler, A. P.; McIntyre, N. R.


    used here takes into account a multiobjective approach, which means that more than one objective functions are evaluated. These are the Nash-Sutcliffe efficiency (NSE) and the Absolute value of the relative bias (Absr-bias). The sensitivity analysis also provided an approximation of the optimal parameter sets so that the residual model error would originate mainly from the datasets and the model structure. JULES performance at the point scale using the default recommended parameter values was variable. The case study area is focused on the Thames catchment and more specifically on the Pang and Lambourn catchments. The examined areas are located in the WarrenFarm site, a grassland livestock site that is high on Lambourn Downs, and the Frilsham Meadow site, a grassland recharge site next to the River Pang. With the incorporation of the optimised parameters the soil moisture performance was considered reasonable so that there is no evidence that the model structure is insufficient in these catchments, and that the challenge is parameter estimation. The greater problem of parameter estimation at larger operational scales is discussed.

  17. Anisotropy and spatial variation of relative permeability and lithologic character of Tensleep Sandstone reservoirs in the Bighorn and Wind River basins, Wyoming. Final technical report, September 15, 1993--October 31, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, T.L.


    This multidisciplinary study was designed to provide improvements in advanced reservoir characterization techniques. This goal was accomplished through: (1) an examination of the spatial variation and anisotropy of relative permeability in the Tensleep Sandstone reservoirs of Wyoming; (2) the placement of that variation and anisotropy into paleogeographic, and depositional regional frameworks; (3) the development of pore-system imagery techniques for the calculation of relative permeability; and (4) reservoir simulations testing the impact of relative permeability anisotropy and spatial variation on Tensleep Sandstone reservoir enhanced oil recovery. Concurrent efforts were aimed at understanding the spatial and dynamic alteration in sandstone reservoirs that is caused by rock-fluid interaction during CO{sub 2} enhanced oil recovery processes. The work focused on quantifying the interrelationship of fluid-rock interaction with lithologic characterization and with fluid characterization in terms of changes in chemical composition and fluid properties. This work establishes new criteria for the susceptibility of Tensleep Sandstone reservoirs to formation alteration that results in wellbore scale damage. This task was accomplished by flow experiments using core material; examination of regional trends in water chemistry; examination of local water chemistry trends the at field scale; and chemical modeling of both the experimental and reservoir systems.

  18. On the connection between morphological and stochastic permeability models of porous media (United States)

    Hristopulos, D. T.


    We present a theoretical framework that connects morphological and stochastic models of the fluid permeability in porous media. Morphological models relate fluid permeability to properties of the pore space geometry, such as the porosity and specific interfacial area. On the other hand, stochastic theories of flow and transport are based on statistical representations of the fluid permeability obtained from the analysis of permeability data, which do not make a direct connection with the pore morphology. Using the local porosity theory, we develop a link between the morphological and stochastic permeability models, and we show how statistical properties follow from the small-scale variability of the morphology.

  19. Unexpected effects of peripherally administered kynurenic acid on cortical spreading depression and related blood–brain barrier permeability

    Directory of Open Access Journals (Sweden)

    Oláh G


    Full Text Available Gáspár Oláh,1 Judit Herédi,1 Ákos Menyhárt,1 Zsolt Czinege,2 Dávid Nagy,1 János Fuzik,1 Kitti Kocsis,1 Levente Knapp,1 Erika Krucsó,1 Levente Gellért,1 Zsolt Kis,1 Tamás Farkas,1 Ferenc Fülöp,3 Árpád Párdutz,4 János Tajti,4 László Vécsei,4 József Toldi1 1Department of Physiology, Anatomy and Neuroscience, 2Department of Software Engineering, 3Institute of Pharmaceutical Chemistry and MTA-SZTE Research Group for Stereochemistry, 4Department of Neurology and MTA-SZTE Neuroscience Research Group, University of Szeged, Szeged, Hungary Abstract: Cortical spreading depression (CSD involves a slowly-propagating depolarization wave in the cortex, which can appear in numerous pathophysiological conditions, such as migraine with aura, stroke, and traumatic brain injury. Neurons and glial cells are also depolarized transiently during the phenomena. CSD is followed by a massive increase in glutamate release and by changes in the brain microcirculation. The aim of this study was to investigate the effects of two N-methyl-D-aspartate receptor antagonists, endogenous kynurenic acid (KYNA and dizocilpine, on CSD and the related blood–brain barrier (BBB permeability in rats. In intact animals, KYNA hardly crosses the BBB but has some positive features as compared with its precursor L-Kynurenine, which is frequently used in animal studies (KYNA cannot be metabolized to excitotoxic agents such as 3-hydroxy-L-kynurenine and quinolinic acid. We therefore investigated the possible effects of peripherally administered KYNA. Repetitive CSD waves were elicited by the application of 1 M KCl solution to the cortex. Direct current-electrocorticograms were measured for 1 hour. Four parameters of the waves were compared. Evans blue dye and fluorescent microscopy were used to study the possible changes in the permeability of the BBB. The results demonstrated that N-methyl-D-aspartate receptor antagonists can reduce the number of CSD waves and decrease

  20. Gut permeability is related to body weight, fatty liver disease, and insulin resistance in obese individuals undergoing weight reduction. (United States)

    Damms-Machado, Antje; Louis, Sandrine; Schnitzer, Anna; Volynets, Valentina; Rings, Andreas; Basrai, Maryam; Bischoff, Stephan C


    Obesity and associated metabolic disorders are related to impairments of the intestinal barrier. We examined lactulose:mannitol (Lac:Man) permeability in obese individuals with and without liver steatosis undergoing a weight-reduction program to test whether an effective weight-loss program improves gut barrier function and whether obese patients with or without liver steatosis differ in this function. Twenty-seven adult, nondiabetic individuals [mean ± SD body mass index (BMI; in kg/m 2 ): 43.7 ± 5.2; 78% with moderate or severe liver steatosis] were included in the follow-up intervention study (n = 13 by month 12). All patients reduced their weight to a mean ± SD BMI of 36.4 ± 5.1 within 12 mo. We assessed barrier functions by the oral Lac:Man and the fecal zonulin tests. Insulin resistance was assessed by the homeostatic model assessment index (HOMA), and liver steatosis by sonography and the fatty liver index (FLI). The Lac:Man ratio and circulating interleukin (IL) 6 concentration decreased during intervention from 0.080 (95% CI: 0.073, 0.093) to 0.027 (95% CI: 0.024, 0.034; P obese patients with steatosis compared with obese patients without. The increased permeability fell to within the previously reported normal range after weight reduction. The data suggest that a leaky gut barrier is linked with liver steatosis and could be a new target for future steatosis therapies. This trial was registered at as NCT01344525. © 2017 American Society for Nutrition.

  1. Quantifying Evaporation in a Permeable Pavement System (United States)

    Studies quantifying evaporation from permeable pavement systems are limited to a few laboratory studies and one field application. This research quantifies evaporation for a larger-scale field application by measuring the water balance from lined permeable pavement sections. Th...

  2. A completely noninvasive method of dissolved oxygen monitoring in disposable small-scale cell culture vessels based on diffusion through permeable vessel walls. (United States)

    Gupta, Priyanka A; Ge, Xudong; Kostov, Yordan; Rao, Govind


    Disposable cell culture vessels are extensively used at small scales for process optimization and validation, but they lack monitoring capabilities. Optical sensors that can be easily adapted for use in small-scale vessels are commercially available for pH, dissolved oxygen (DO), and dissolved carbon dioxide (DCO2 ). However, their use has been limited due to the contamination and compatibility issues. We have developed a novel solution to these problems for DO monitoring. Oxygen diffusion through permeable vessel wall can be exploited for noninvasive monitoring. An optical oxygen sensor can be placed outside the oxygen permeable vessel wall thereby allowing oxygen diffusing through the vessel wall to be detected by the sensor. This way the sensor stays separate from the cell culture and there are no concerns about contaminants or leachants. Here we implement this method for two cell culture devices: polystyrene-made T-75 tissue culture flask and fluorinated ethylene propylene (FEP)-made Vuelife(®) cell culture bag. Additionally, mammalian and microbial cell cultures were performed in Vuelife(®) cell culture bags, proving that a sensor placed outside can be used to track changes in cell cultures. This approach toward noninvasive monitoring will help in integrating cell culture vessels with sensors in a seamless manner. © 2013 American Institute of Chemical Engineers.

  3. Anisotropy and spatial variation of relative permeability and lithologic character of Tensleep Sandstone reservoirs in the Bighorn and Wind River basins, Wyoming. Annual report, September 15, 1993--September 30, 1994

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, T.L.


    The principal focus of this project is to evaluate the importance of relative permeability anisotropy with respect to other known geologic and engineering production concepts. This research is to provide improved strategies for enhanced oil recovery from the Tensleep Sandstone oil reservoirs in the Bighorn and Wind River basins, Wyoming. The Tensleep Sandstone contains the largest potential reserves within reservoirs which are candidates for EOR processes in the State of Wyoming. Although this formation has produced billions of barrels of oil, in some fields, as little as one in seven barrels of discovered oil is recoverable by current primary and secondary techniques. Because of the great range of {degree}API gravities of the oils produced from the Tensleep Sandstone reservoirs, the proposed study concentrates on establishing an understanding of the spatial variation and anisotropy of relative permeability within the Tensleep Sandstone. This research is to associate those spatial distributions and anisotropies with the depositional subfacies and zones of diagenetic alteration found within the Tensleep Sandstone. In addition, these studies are being coupled with geochemical modeling and coreflood experiments to investigate the potential for wellbore scaling and formation damage anticipated during EOR processes (e.g., C0{sub 2} flooding). This multidisciplinary project will provide a regional basis for EOR strategies which can be clearly mapped and efficiently applied to the largest potential target reservoir in the State of Wyoming. Additionally, the results of this study have application to all eolian reservoirs through the correlations of relative permeability variation and anisotropy with eolian depositional lithofacies.

  4. A free software for pore-scale modelling: solving Stokes equation for velocity fields and permeability values in 3D pore geometries

    KAUST Repository

    Gerke, Kirill


    In this contribution we introduce a novel free software which solves the Stokes equation to obtain velocity fields for low Reynolds-number flows within externally generated 3D pore geometries. Provided with velocity fields, one can calculate permeability for known pressure gradient boundary conditions via Darcy\\'s equation. Finite-difference schemes of 2nd and 4th order of accuracy are used together with an artificial compressibility method to iteratively converge to a steady-state solution of Stokes\\' equation. This numerical approach is much faster and less computationally demanding than the majority of open-source or commercial softwares employing other algorithms (finite elements/volumes, lattice Boltzmann, etc.) The software consists of two parts: 1) a pre and post-processing graphical interface, and 2) a solver. The latter is efficiently parallelized to use any number of available cores (the speedup on 16 threads was up to 10-12 depending on hardware). Due to parallelization and memory optimization our software can be used to obtain solutions for 300x300x300 voxels geometries on modern desktop PCs. The software was successfully verified by testing it against lattice Boltzmann simulations and analytical solutions. To illustrate the software\\'s applicability for numerous problems in Earth Sciences, a number of case studies have been developed: 1) identifying the representative elementary volume for permeability determination within a sandstone sample, 2) derivation of permeability/hydraulic conductivity values for rock and soil samples and comparing those with experimentally obtained values, 3) revealing the influence of the amount of fine-textured material such as clay on filtration properties of sandy soil. This work was partially supported by RSF grant 14-17-00658 (pore-scale modelling) and RFBR grants 13-04-00409-a and 13-05-01176-a.

  5. The obesity-related peptide leptin sensitizes cardiac mitochondria to calcium-induced permeability transition pore opening and apoptosis.

    Directory of Open Access Journals (Sweden)

    Eduardo Martinez-Abundis

    Full Text Available The obesity-related 16 kDa peptide leptin is synthesized primarily in white adipocytes although its production has been reported in other tissues including the heart. There is emerging evidence that leptin may contribute to cardiac pathology especially that related to myocardial remodelling and heart failure. In view of the importance of mitochondria to these processes, the goal of the present study is to determine the effect of leptin on mitochondria permeability transition pore opening and the potential consequence in terms of development of apoptosis. Experiments were performed using neonatal rat ventricular myocytes exposed to 3.1 nM (50 ng/ml leptin for 24 hours. Mitochondrial transition pore opening was analyzed as the capacity of mitochondria to retain the dye calcein-AM in presence of 200 µM CaCl2. Leptin significantly increased pore opening although the effect was markedly more pronounced in digitonin-permeabilized myocytes in the presence of calcium with both effects prevented by the transition pore inhibitor sanglifehrin A. These effects were associated with increased apoptosis as evidenced by increased TUNEL staining and caspase 3 activity, both of which were prevented by the transition pore inhibitor sanglifehrin A. Leptin enhanced Stat3 activation whereas a Stat 3 inhibitor peptide prevented leptin-induced mitochondrial transition pore opening as well as the hypertrophic and pro-apoptotic effects of the peptide. Inhibition of the RhoA/ROCK pathway prevented the hypertrophic response to leptin but had no effect on increased pore opening following leptin administration. We conclude that leptin can enhance calcium-mediated, Stat3-dependent pro-apoptotic effects as a result of increased mitochondrial transition pore opening and independently of its hypertrophic actions. Leptin may therefore contribute to mitochondrial dysfunction and the development of apoptosis in the diseased myocardium particularly under conditions of excessive

  6. Gut Microbiota Richness and Composition and Dietary Intake of Overweight Pregnant Women Are Related to Serum Zonulin Concentration, a Marker for Intestinal Permeability. (United States)

    Mokkala, Kati; Röytiö, Henna; Munukka, Eveliina; Pietilä, Sami; Ekblad, Ulla; Rönnemaa, Tapani; Eerola, Erkki; Laiho, Asta; Laitinen, Kirsi


    Increased intestinal permeability may precede adverse metabolic conditions. The extent to which the composition of the gut microbiota and diet contribute to intestinal permeability during pregnancy is unknown. The aim was to investigate whether the gut microbiota and diet differ according to serum zonulin concentration, a marker of intestinal permeability, in overweight pregnant women. This cross-sectional study included 100 overweight women [mean age: 29 y; median body mass index (in kg/m(2)): 30] in early pregnancy (microbiota by 16S ribosomal RNA sequencing, and dietary intake of macro- and micronutrients from 3-d food diaries. The Mann-Whitney U test was used for pairwise comparisons and linear regression and Spearman's nonparametric correlations for relations between serum zonulin and other outcome variables. Women were divided into "low" (microbiota (Chao 1, observed species and phylogenetic diversity) was higher in the low zonulin group than in the high zonulin group (P = 0.01). The abundances of Bacteroidaceae and Veillonellaceae, Bacteroides and Blautia, and Blautia sp. were lower and of Faecalibacterium and Faecalibacterium prausnitzii higher (P composition of the gut microbiota and the intake of n-3 PUFAs, fiber, and a range of vitamins and minerals in overweight pregnant women are associated with serum zonulin concentration. Modification of the gut microbiota and diet may beneficially affect intestinal permeability, leading to improved metabolic health of both the mother and fetus. This trial was registered at as NCT01922791. © 2016 American Society for Nutrition.

  7. The relation among porosity, permeability, and specific surface of chalk from the Gorm field, Danish North Sea

    DEFF Research Database (Denmark)

    Jeanette, Mortensen; Engstrøm, Finn; Lind, Ida


    X. On 24 of the core plugs the specific surface was determined by BET and on 14 of these samples image analysis was made. The data was rationalized by the use of the Kozeny equation and it was found that each geologic unit had a characteristic relationship between porosity, permeability and specific...

  8. An Integrated Capillary, Buoyancy, and Viscous-Driven Model for Brine/CO2Relative Permeability in a Compositional and Parallel Reservoir Simulator

    KAUST Repository

    Kong, X.


    The effectiveness of CO2 storage in the saline aquifers is governed by the interplay of capillary, viscous, and buoyancy forces. Recent experimental study reveals the impact of pressure, temperature, and salinity on interfacial tension (IFT) between CO2 and brine. The dependence of CO2-brine relative permeability and capillary pressure on pressure (IFT) is also clearly evident in published experimental results. Improved understanding of the mechanisms that control the migration and trapping of CO2 in subsurface is crucial to design future storage projects that warrant long-term and safe containment. Simulation studies ignoring the buoyancy and also variation in interfacial tension and the effect on the petrophysical properties such as trapped CO2 saturations, relative permeability, and capillary pressure have a poor chance of making accurate predictions of CO2 injectivity and plume migration. We have developed and implemented a general relative permeability model that combines effects of pressure gradient, buoyancy, and IFT in an equation of state (EOS) compositional and parallel simulator. The significance of IFT variations on CO2 migration and trapping is assessed.

  9. User's Guide for Hysteretic Capillary Pressure and Relative Permeability Functions in iTOUGH2

    Energy Technology Data Exchange (ETDEWEB)

    Doughty, C.A.


    The precursor of TOUGH2, TOUGH, was originally developed with non-hysteretic characteristic curves. Hysteretic capillary pressure functions were implemented in TOUGH in the late 1980s by Niemi and Bodvarsson (1988), and hysteretic capillary pressure and relative permeability functions were added to iTOUGH2 about ten years later by Finsterle et al. (1998). Recently, modifications were made to the iTOUGH2 hysteretic formulation to make it more robust and efficient (Doughty, 2007). Code development is still underway, with the ultimate goal being a hysteretic module that fits into the standard TOUGH2 (Pruess et al., 1991) framework. This document provides a user's guide for the most recent version of the hysteretic code, which runs within iTOUGH2 (Finsterle, 1999a,b,c). The current code differs only slightly from what was presented in Doughty (2007), hence that document provides the basic information on the processes being modeled and how they are conceptualized. This document focuses on a description of the user-specified parameters required to run hysteretic iTOUGH2. In the few instances where the conceptualization differs from that of Doughty (2007), the features described here are the current ones. Sample problems presented in this user's guide use the equation-of-state module ECO2N (Pruess, 2005). The components present in ECO2N are H{sub 2}O, NaCl, and CO{sub 2}. Two fluid phases and one solid phase are considered: an aqueous phase, which primarily consists of liquid H2O and may contain dissolved NaCl and CO{sub 2}; a supercritical phase which primarily consists of CO{sub 2}, but also includes a small amount of gaseous H{sub 2}O; and a solid phase consisting of precipitated NaCl. Details of the ECO2N formulation may be found in Pruess (2005). The aqueous phase is the wetting phase and is denoted ''liquid'', whereas the supercritical phase is the non-wetting phase and is denoted ''gas''. The hysteretic formalism

  10. A relative permeability model to derive fractional-flow functions of water-alternating-gas and surfactant-alternating-gas foam core-floods (United States)

    Idrees Al-Mossawy, Mohammed; Demiral, Birol; Raja, D. M. Anwar


    Foam is used in enhanced oil recovery to improve the sweep efficiency by controlling the gas mobility. The surfactant-alternating-gas (SAG) foam process is used as an alternative to the water-alternating-gas (WAG) injection. In the WAG technique, the high mobility and the low density of the gas lead the gas to flow in channels through the high permeability zones of the reservoir and to rise to the top of the reservoir by gravity segregation. As a result, the sweep efficiency decreases and there will be more residual oil in the reservoir. The foam can trap the gas in liquid films and reduces the gas mobility. The fractional-flow method describes the physics of immiscible displacements in porous media. Finding the water fractional flow theoretically or experimentally as a function of the water saturation represents the heart of this method. The relative permeability function is the conventional way to derive the fractional-flow function. This study presents an improved relative permeability model to derive the fractional-flow functions for WAG and SAG foam core-floods. The SAG flow regimes are characterized into weak foam, strong foam without a shock front and strong foam with a shock front.

  11. Special relativity at the quantum scale. (United States)

    Lam, Pui K


    It has been suggested that the space-time structure as described by the theory of special relativity is a macroscopic manifestation of a more fundamental quantum structure (pre-geometry). Efforts to quantify this idea have come mainly from the area of abstract quantum logic theory. Here we present a preliminary attempt to develop a quantum formulation of special relativity based on a model that retains some geometric attributes. Our model is Feynman's "checker-board" trajectory for a 1-D relativistic free particle. We use this model to guide us in identifying (1) the quantum version of the postulates of special relativity and (2) the appropriate quantum "coordinates". This model possesses a useful feature that it admits an interpretation both in terms of paths in space-time and in terms of quantum states. Based on the quantum version of the postulates, we derive a transformation rule for velocity. This rule reduces to the Einstein's velocity-addition formula in the macroscopic limit and reveals an interesting aspect of time. The 3-D case, time-dilation effect, and invariant interval are also discussed in term of this new formulation. This is a preliminary investigation; some results are derived, while others are interesting observations at this point.

  12. Randomised controlled study comparing comfort-related outcomes between two rigid gas permeable (RGP) lenses with different sessile drop contact angles. (United States)

    Fortuin, Marten F; Schilperoort, John; Evans, Bruce Jw; Edgar, David F; Manon, Hector M Tello; Kiers, Henri


    To compare comfort-related outcomes when wearing rigid gas permeable (RGP) contact lenses made of two different materials and using two cleaning regimes. In a double-masked lens material cross-over study, subjects (n = 28 who completed the study) were refitted with new lenses made from (A) Boston XO material in one eye and made from (B) ONSI-56 material in the other eye. The lenses made from materials A and B were worn on the right eye and the left eye following the pattern AB-BA-AB (or vice versa) during the first, second, and third 5 week trial periods respectively. Miraflow cleaner (1st and 2nd period) was replaced by Boston Advance cleaner in the 3rd period. Comfort-related outcomes were assessed by a numerical rating scale (NRS) after each period. Subjects rated six comfort-related factors: satisfaction, sharpness of vision, end of day comfort, maximum comfortable wearing time, maximum wearing time and foreign body feeling. Additionally we obtained subjects' preferences for type of lens and lens cleaner during an exit interview. The sessile drop method was used to measure static contact angles. The mean of the contact angle measured for the Boston XO material was 93.3° and for the ONSI-56 material was 75.8 °. Mean 'end of the day comfort', 'satisfaction' and 'lens feeling' scores reached statistical significance (anova periods 1, 2 and 3, p's: 0.005, 0.028, 0.046, n = 23) with marginal differences in favour of those eyes that had worn lenses made of the ONSI-56 material (differences in mean scores on a 1-10 NRS never exceeded 0.7, 0.5 and 0.2 points in periods 1, 2, 3 respectively). At the exit interview 60% of the subjects (n = 17) were not able to express a preference for wearing either of the lenses, while 29% reported some preference for lenses made of the ONSI-56 material (n = 8) and 11% for wearing lenses made of the Boston XO material (n = 3) within one or more periods. The differences in comfort-related outcomes between contact lenses made from two

  13. Performance of a field-scale permeable reactive barrier based on organic substrate and zero-valent iron for in situ remediation of acid mine drainage. (United States)

    Gibert, Oriol; Cortina, José Luis; de Pablo, Joan; Ayora, Carlos


    A permeable reactive barrier (PRB) was installed in Aznalcóllar (Spain) in order to rehabilitate the Agrio aquifer groundwater severely contaminated with acid mine drainage after a serious mining accident. The filling material of the PRB consisted of a mixture of calcite, vegetal compost and, locally, Fe(0) and sewage sludge. Among the successes of the PRB are the continuous neutralisation of pH and the removal of metals from groundwater within the PRB (removals of >95%). Among the shortcomings are the improper PRB design due to the complexity of the internal structure of the Agrio alluvial deposits (which resulted in an inefficient capture of the contaminated plume), the poor degradability of the compost used and the short residence time within the PRB (which hindered a complete sulphate reduction), the clogging of a section of the PRB and the heterogeneities of the filling material (which resulted in preferential flows within the PRB). Undoubtedly, it is only through accumulated experience at field-scale systems that the potentials and limits of the PRB technology can be determined.

  14. Polymeric membrane materials: new aspects of empirical approaches to prediction of gas permeability parameters in relation to permanent gases, linear lower hydrocarbons and some toxic gases. (United States)

    Malykh, O V; Golub, A Yu; Teplyakov, V V


    Membrane gas separation technologies (air separation, hydrogen recovery from dehydrogenation processes, etc.) use traditionally the glassy polymer membranes with dominating permeability of "small" gas molecules. For this purposes the membranes based on the low free volume glassy polymers (e.g., polysulfone, tetrabromopolycarbonate and polyimides) are used. On the other hand, an application of membrane methods for VOCs and some toxic gas recovery from air, separation of the lower hydrocarbons containing mixtures (in petrochemistry and oil refining) needs the membranes with preferable penetration of components with relatively larger molecular sizes. In general, this kind of permeability is characterized for rubbers and for the high free volume glassy polymers. Data files accumulated (more than 1500 polymeric materials) represent the region of parameters "inside" of these "boundaries." Two main approaches to the prediction of gas permeability of polymers are considered in this paper: (1) the statistical treatment of published transport parameters of polymers and (2) the prediction using model of ≪diffusion jump≫ with consideration of the key properties of the diffusing molecule and polymeric matrix. In the frames of (1) the paper presents N-dimensional methods of the gas permeability estimation of polymers using the correlations "selectivity/permeability." It is found that the optimal accuracy of prediction is provided at n=4. In the frames of the solution-diffusion mechanism (2) the key properties include the effective molecular cross-section of penetrating species to be responsible for molecular transportation in polymeric matrix and the well known force constant (ε/k)(eff i) of {6-12} potential for gas-gas interaction. Set of corrected effective molecular cross-section of penetrant including noble gases (He, Ne, Ar, Kr, Xe), permanent gases (H(2), O(2), N(2), CO), ballast and toxic gases (CO(2), NO(,) NO(2), SO(2), H(2)S) and linear lower hydrocarbons (CH(4

  15. Numerical Aspects Related to the Dynamic Update of Anisotropic Permeability Field During the Transport of Nanoparticles in the Subsurface

    KAUST Repository

    Chen, Meng-Huo


    Nanoparticles are particles that are between 1 and 100 nanometers in size. They present possible dangers to the environment due to the high surface to volume ratio, which can make the particles very reactive or catalytic. Furthermore, rapid increase in the implementation of nanotechnologies has released large amount of the nanowaste into the environment. In the last two decades, transport of nanoparticles in the subsurface and the potential hazard they impose to the environment have attracted the attention of researchers. In this work, we use numerical simulation to investigate the problem regarding the transport phenomena of nanoparticles in anisotropic porous media. We consider the case in which the permeability in the principal direction components will vary with respect to time. The interesting thing in this case is the fact that the anisotropy could disappear with time. We investigate the effect of the degenerating anisotropy on various fields such as pressure, porosity, concentration and velocities.

  16. Utility-scale system preventive and failure-related maintenance

    Energy Technology Data Exchange (ETDEWEB)

    Jennings, C.; Hutchinson, P.


    This paper describes the design and performance background on PVUSA utility-scale systems at Davis and Kerman, California, and reports on a preventative and failure-related maintenance approach and costs.

  17. Scale relativity theory and integrative systems biology: 1. Founding principles and scale laws. (United States)

    Auffray, Charles; Nottale, Laurent


    In these two companion papers, we provide an overview and a brief history of the multiple roots, current developments and recent advances of integrative systems biology and identify multiscale integration as its grand challenge. Then we introduce the fundamental principles and the successive steps that have been followed in the construction of the scale relativity theory, and discuss how scale laws of increasing complexity can be used to model and understand the behaviour of complex biological systems. In scale relativity theory, the geometry of space is considered to be continuous but non-differentiable, therefore fractal (i.e., explicitly scale-dependent). One writes the equations of motion in such a space as geodesics equations, under the constraint of the principle of relativity of all scales in nature. To this purpose, covariant derivatives are constructed that implement the various effects of the non-differentiable and fractal geometry. In this first review paper, the scale laws that describe the new dependence on resolutions of physical quantities are obtained as solutions of differential equations acting in the scale space. This leads to several possible levels of description for these laws, from the simplest scale invariant laws to generalized laws with variable fractal dimensions. Initial applications of these laws to the study of species evolution, embryogenesis and cell confinement are discussed.

  18. An allometric scaling relation based on logistic growth of cities

    CERN Document Server

    Chen, Yanguang


    The relationships between urban area and population size have been empirically demonstrated to follow the scaling law of allometric growth. This allometric scaling is based on exponential growth of city size and can be termed "exponential allometry", which is associated with the concepts of fractals. However, both city population and urban area comply with the course of logistic growth rather than exponential growth. In this paper, I will present a new allometric scaling based on logistic growth to solve the abovementioned problem. The logistic growth is a process of replacement dynamics. Defining a pair of replacement quotients as new measurements, which are functions of urban area and population, we can derive an allometric scaling relation from the logistic processes of urban growth, which can be termed "logistic allometry". The exponential allometric relation between urban area and population is the approximate expression of the logistic allometric equation when the city size is not large enough. The prop...

  19. Constraining cosmological ultralarge scale structure using numerical relativity (United States)

    Braden, Jonathan; Johnson, Matthew C.; Peiris, Hiranya V.; Aguirre, Anthony


    Cosmic inflation, a period of accelerated expansion in the early universe, can give rise to large amplitude ultralarge scale inhomogeneities on distance scales comparable to or larger than the observable universe. The cosmic microwave background (CMB) anisotropy on the largest angular scales is sensitive to such inhomogeneities and can be used to constrain the presence of ultralarge scale structure (ULSS). We numerically evolve nonlinear inhomogeneities present at the beginning of inflation in full general relativity to assess the CMB quadrupole constraint on the amplitude of the initial fluctuations and the size of the observable universe relative to a length scale characterizing the ULSS. To obtain a statistically meaningful ensemble of simulations, we adopt a toy model in which inhomogeneities are injected along a preferred direction. We compute the likelihood function for the CMB quadrupole including both ULSS and the standard quantum fluctuations produced during inflation. We compute the posterior given the observed CMB quadrupole, finding that when including gravitational nonlinearities, ULSS curvature perturbations of order unity are allowed by the data, even on length scales not too much larger than the size of the observable universe. To demonstrate the robustness of our conclusions, we also explore a semianalytic model for the ULSS which reproduces our numerical results for the case of planar symmetry, and which can be extended to ULSS with a three-dimensional inhomogeneity structure. Our results illustrate the utility and importance of numerical relativity for constraining early universe cosmology.

  20. Functional Independent Scaling Relation for ORR/OER Catalysts

    DEFF Research Database (Denmark)

    Christensen, Rune; Hansen, Heine Anton; Dickens, Colin F.


    A widely used adsorption energy scaling relation between OH* and OOH* intermediates in the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), has previously been determined using density functional theory and shown to dictate a minimum thermodynamic overpotential for both...... reactions. Here, we show that the oxygen-oxygen bond in the OOH* intermediate is, however, not well described with the previously used class of exchange-correlation functionals. By quantifying and correcting the systematic error, an improved description of gaseous peroxide species versus experimental data...... and a reduction in calculational uncertainty is obtained. For adsorbates, we find that the systematic error largely cancels the vdW interaction missing in the original determination of the scaling relation. An improved scaling relation, which is fully independent of the applied exchange-correlation functional...

  1. Matrix injection of relative permeability modifier for water control applied in Brazil basins; Injecao matricial de modificadores de permeabilidade relativa para controle de producao de agua aplicado nas bacias petroliferas brasileiras

    Energy Technology Data Exchange (ETDEWEB)

    Marchi, Flavio; Stefan, Rodolfo; Mendonca, Paulo; Ferreira, Antonio; Silva, Charles; Fonseca, Ana Isoila [BJ Services do Brasil Ltda., Macae, Rio de Janeiro, RJ (Brazil); Melo, Ricardo C.B. [BJ Services Company Africa Ltd., Angola (Angola)


    One of the biggest challenges for the oil industry, even at the beginning of well's production, and principally when the well is producing, is how to reduce and handling the produced water on this process. A conservative estimation says for each barrel of produced oil you have 5 or 6 barrels of formation's water. Some factors must be considerable to establish and maintain a carefully management of this effluent, for example the volume of produced water, which is always growing due to the reservoir maturation and for the secondary recovery process; salt content; residual oil and chemical products presence. Water production is the cause of several problems on wells, like scales, organic deposits or starting the process of formation's sand production induced by fines migration. As a consequence, a cost increment of production is observed due to hydrocarbon/water separation and destination of produced water. The same way, is extremely expensive to manage the even bigger volume, which demands efforts to re-inject the water, treatment which avoid or minimize possible environment impacts, development of new equipment and materials which helps and resists to the effects of produced water. Not inherent reservoir's cause can be several, like bad isolated water zones by cement fail, wrong determination of perforated interval, which is easier to use aid methods. When the water production is directly associated to reservoir, by conning, channeling and/or fingering, generally associated to mobility difference between water and oil, the nowadays most efficient treatment is the injection of relative permeability modifier. This paper will present techniques and results obtained with matrix injection in some fields by the use of the last generation of RPM (relative permeability modifier). (author)

  2. General scaling relations for locomotion in granular media (United States)

    Slonaker, James; Motley, D. Carrington; Zhang, Qiong; Townsend, Stephen; Senatore, Carmine; Iagnemma, Karl; Kamrin, Ken


    Inspired by dynamic similarity in fluid systems, we have derived a general dimensionless form for locomotion in granular materials, which is validated in experiments and discrete element method (DEM) simulations. The form instructs how to scale size, mass, and driving parameters in order to relate dynamic behaviors of different locomotors in the same granular media. The scaling can be derived by assuming intrusion forces arise from resistive force theory or equivalently by assuming the granular material behaves as a continuum obeying a frictional yield criterion. The scalings are experimentally confirmed using pairs of wheels of various shapes and sizes under many driving conditions in a common sand bed. We discuss why the two models provide such a robust set of scaling laws even though they neglect a number of the complexities of granular rheology. Motivated by potential extraplanetary applications, the dimensionless form also implies a way to predict wheel performance in one ambient gravity based on tests in a different ambient gravity. We confirm this using DEM simulations, which show that scaling relations are satisfied over an array of driving modes even when gravity differs between scaled tests.

  3. An allometric scaling relation based on logistic growth of cities (United States)

    Chen, Yanguang


    The relationships between urban area and population size have been empirically demonstrated to follow the scaling law of allometric growth. This allometric scaling is based on exponential growth of city size and can be termed "exponential allometry", which is associated with the concepts of fractals. However, both city population and urban area comply with the course of logistic growth rather than exponential growth. In this paper, I will present a new allometric scaling based on logistic growth to solve the abovementioned problem. The logistic growth is a process of replacement dynamics. Defining a pair of replacement quotients as new measurements, which are functions of urban area and population, we can derive an allometric scaling relation from the logistic processes of urban growth, which can be termed "logistic allometry". The exponential allometric relation between urban area and population is the approximate expression of the logistic allometric equation when the city size is not large enough. The proper range of the allometric scaling exponent value is reconsidered through the logistic process. Then, a medium-sized city of Henan Province, China, is employed as an example to validate the new allometric relation. The logistic allometry is helpful for further understanding the fractal property and self-organized process of urban evolution in the right perspective.

  4. Permeability prediction in chalks

    DEFF Research Database (Denmark)

    Alam, Mohammad Monzurul; Fabricius, Ida Lykke; Prasad, Manika


    prediction, so we have investigated the use of velocity data to predict permeability. The compressional velocity fromwireline logs and core plugs of the chalk reservoir in the South Arne field, North Sea, has been used for this study. We compared various methods of permeability prediction from velocities......-permeability relationships were replaced by relationships between velocity of elastic waves and permeability using laboratory data, and the relationships were then applied to well-log data. We found that the permeability prediction in chalk and possibly other sediments with large surface areas could be improved...

  5. Regional-scale risk assessment methodology using the Relative ...

    African Journals Online (AJOL)


    Apr 18, 2012 ... paper presents an integrated approach to carry out regional-scale ecological risk assessments using a Relative Risk Model. (RRM) adapted ..... Recreational activities. Dams&wiers. Plantations. Gold mine. Habitat alteration. Sugar mill. Sugar. Mixed. Flow alterations. Forestry. 1. Irrigation - dam. Exotic fish.

  6. Violence-Related Attitudes and Beliefs: Scale Construction and Psychometrics (United States)

    Brand, Pamela A.; Anastasio, Phyllis A.


    The 50-item Violence-Related Attitudes and Beliefs Scale (V-RABS) includes three subscales measuring possible causes of violent behavior (environmental influences, biological influences, and mental illness) and four subscales assessing possible controls of violent behavior (death penalty, punishment, prevention, and catharsis). Each subscale…

  7. Film Permeability Determination Using Static Permeability Cells (United States)

    The permeability of tarps to soil fumigant pesticides varies depending on the active ingredient chemical: dimethyl disulfide (DMDS), methyl bromide, chloropicrin, or other. The diffusion rate can be represented by the mass transfer coefficient (MTC).

  8. Estimation of soil permeability

    Directory of Open Access Journals (Sweden)

    Amr F. Elhakim


    Full Text Available Soils are permeable materials because of the existence of interconnected voids that allow the flow of fluids when a difference in energy head exists. A good knowledge of soil permeability is needed for estimating the quantity of seepage under dams and dewatering to facilitate underground construction. Soil permeability, also termed hydraulic conductivity, is measured using several methods that include constant and falling head laboratory tests on intact or reconstituted specimens. Alternatively, permeability may be measured in the field using insitu borehole permeability testing (e.g. [2], and field pumping tests. A less attractive method is to empirically deduce the coefficient of permeability from the results of simple laboratory tests such as the grain size distribution. Otherwise, soil permeability has been assessed from the cone/piezocone penetration tests (e.g. [13,14]. In this paper, the coefficient of permeability was measured using field falling head at different depths. Furthermore, the field coefficient of permeability was measured using pumping tests at the same site. The measured permeability values are compared to the values empirically deduced from the cone penetration test for the same location. Likewise, the coefficients of permeability are empirically obtained using correlations based on the index soil properties of the tested sand for comparison with the measured values.

  9. Cloning of ovocalyxin-36, a novel chicken eggshell protein related to lipopolysaccharide-binding proteins, bactericidal permeability-increasing proteins, and plunc family proteins. (United States)

    Gautron, Joël; Murayama, Emi; Vignal, Alain; Morisson, Mireille; McKee, Marc D; Réhault, Sophie; Labas, Valérie; Belghazi, Maya; Vidal, Mary-Laure; Nys, Yves; Hincke, Maxwell T


    The avian eggshell is a composite biomaterial composed of noncalcifying eggshell membranes and the overlying calcified shell matrix. The shell is deposited in a uterine fluid where the concentration of different protein species varies at different stages of its formation. The role of avian eggshell proteins during shell formation remains poorly understood, and we have sought to identify and characterize the individual components in order to gain insight into their function during elaboration of the eggshell. In this study, we have used direct sequencing, immunochemistry, expression screening, and EST data base mining to clone and characterize a 1995-bp full-length cDNA sequence corresponding to a novel chicken eggshell protein that we have named Ovocalyxin-36 (OCX-36). Ovocalyxin-36 protein was only detected in the regions of the oviduct where egg-shell formation takes place; uterine OCX-36 message was strongly up-regulated during eggshell calcification. OCX-36 localized to the calcified eggshell predominantly in the inner part of the shell, and to the shell membranes. BlastN data base searching indicates that there is no mammalian version of OCX-36; however, the protein sequence is 20-25% homologous to proteins associated with the innate immune response as follows: lipopolysaccharide-binding proteins, bactericidal permeability-increasing proteins, and Plunc family proteins. Moreover, the genomic organization of these proteins and OCX-36 appears to be highly conserved. These observations suggest that OCX-36 is a novel and specific chicken eggshell protein related to the superfamily of lipopolysaccharide-binding proteins/bactericidal permeability-increasing proteins and Plunc proteins. OCX-36 may therefore participate in natural defense mechanisms that keep the egg free of pathogens.

  10. Development and initial validity of the Object Relations Rating Scale. (United States)

    Diguer, Louis; Gamache, Dominick; Laverdière, Olivier


    The aim of this study was to report on the development and the initial validation of the Object Relations Rating Scale (ORRS), which is a measure of in-session enactments of object relations that draws on a psychodynamic conceptualization of personality organization. Forty participants were included in the study, distributed among neurotic, borderline and psychotic personality organizations (PO). Results showed that the interrater reliability of this new measure is good. Two tests of criterion validity support the validity of the measure: the ORRS discriminates well between the three PO groups and it correlates in expected ways with five PO dimensions. Finally, ORRS scales that pertain to the degree of in-session object relation enactments correlated with a measure of transference intensity (convergent validity), and correlations with therapists experience were low as expected (discriminant validity).

  11. Clogging in permeable concrete: A review. (United States)

    Kia, Alalea; Wong, Hong S; Cheeseman, Christopher R


    Permeable concrete (or "pervious concrete" in North America) is used to reduce local flooding in urban areas and is an important sustainable urban drainage system. However, permeable concrete exhibits reduction in permeability due to clogging by particulates, which severely limits service life. This paper reviews the clogging mechanism and current mitigating strategies in order to inform future research needs. The pore structure of permeable concrete and characteristics of flowing particulates influence clogging, which occurs when particles build-up and block connected porosity. Permeable concrete requires regular maintenance by vacuum sweeping and pressure washing, but the effectiveness and viability of these methods is questionable. The potential for clogging is related to the tortuosity of the connected porosity, with greater tortuosity resulting in increased potential for clogging. Research is required to develop permeable concrete that can be poured on-site, which produces a pore structure with significantly reduced tortuosity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Gas-Oil Relative Permeability and Residual Oil Saturation as Related to Displacement Instability and Dimensionless Numbers Étude de la perméabilité relative gaz-huile et de la saturation en huile résiduelle dans le cas d’une instabilité de déplacement et des nombres sans dimension s’y rapportant

    Directory of Open Access Journals (Sweden)

    Rostami B.


    Full Text Available Displacement experiments of the gas-oil system are performed on long core scale models by varying the petrophysical properties and flowing conditions. Experiments are conducted in situations where capillary, gravity and viscous forces are comparable. From oil production history and picture analysis, the threshold for the stability is determined. The experimental findings are comparable to the results of a gradient percolation theory. The effect of destabilized front velocity on relative permeability and residual saturation is investigated. The relative permeabilities determined by using analytical and numerical approaches indicate that higher displacement velocity leads to a higher gas relative permeability and lower oil relative permeability. The remaining oil saturation is found to be much higher for displacement velocity above the stabilized criterion. Displacement morphology including the average remaining oil saturation is then described using dimensionless groups expressed as Bond and capillary number. Experimentally determined remaining oil saturation shows a direct and inverse relation to the capillary and Bond number respectively. Hence, a combined dimensionless group has been proposed to generalize the estimation of remaining and residual oil saturations under the range of dimensionless numbers studied here. Des expériences de déplacement gaz-huile ont été réalisées sur des modèles mis à l’échelle de carottes de grande longueur en faisant varier les propriétés pétrophysiques et les conditions d’écoulement. Pour ces expériences, les forces en présence, capillaires, gravitaires et visqueuses, sont comparables. Le seuil de stabilité est déterminé à partir de l’historique de production et de l’analyse d’images. Les résultats des expériences sont comparables aux conclusions de la théorie de la percolation en gradient. On étudie ensuite l’effet de l’instabilité du front de déplacement sur la perm

  13. Permeability estimated from subsurface data: Grayburg Formation, Dune field, Crane County, west Texas

    Energy Technology Data Exchange (ETDEWEB)

    Lucia, F.J. (Bureau of Economic Geology, Austin, TX (USA))


    Dune field contains little vuggy porosity so total porosity and particle size become the determining factors. Three pore-geometry families are distiguished: intergranular porosity between 300-{mu}m grains in grainstones, intercrystalline porosity between 50-{mu}m dolomite crystals in dolomitized wackestones/packestones, and rocks with an intimate mixture of these two end members. Unique porosity-permeability transform functions for these three pore-type families are determined. The presence of up to 55% gypsum in Dune field complicates calculations of total porosity. Particle size was determined by relating particle size to irreducible water saturation. In the oil column, irreducible water saturation is a function of interparticle porosity and particle size. Assuming similar porosity values, rocks with finer pores will have higher water saturations than those with larger pores. In Dune field, intergranular pores are larger than the intercrystalline pores, and saturation values calculated from wireline logs show lower water saturations for the intergranular pore-type families than for the intercrystalline pore-type families. The mixed family is intermediate. Permeabilities are calculated from sonic and resistivity logs by determining the pore-type family from the saturation values and the permeability from the porosity-permeability relationship for that family. The resulting permeability profiles compare favorably with core analysis profiles. Permeability logs are correlated assuming parallel beds, and permeability cross sections and permeability-thickness maps are prepared. The results show that the reservoir can be divided into upper and lower members separated by a 25-ft permeability barrier. The permeability in either member varies on scales from 600 ft to 1 mi and can be related to depositional and diagenetic facies.

  14. Scale relativity and fractal space-time a new approach to unifying relativity and quantum mechanics

    CERN Document Server

    Nottale, Laurent


    This book provides a comprehensive survey of the development of the theory of scale relativity and fractal space-time. It suggests an original solution to the disunified nature of the classical-quantum transition in physical systems, enabling the basis of quantum mechanics on the principle of relativity, provided this principle is extended to scale transformations of the reference system. In the framework of such a newly generalized relativity theory (including position, orientation, motion and now scale transformations), the fundamental laws of physics may be given a general form that unifies

  15. Implicit Priors in Galaxy Cluster Mass and Scaling Relation Determinations (United States)

    Mantz, A.; Allen, S. W.


    Deriving the total masses of galaxy clusters from observations of the intracluster medium (ICM) generally requires some prior information, in addition to the assumptions of hydrostatic equilibrium and spherical symmetry. Often, this information takes the form of particular parametrized functions used to describe the cluster gas density and temperature profiles. In this paper, we investigate the implicit priors on hydrostatic masses that result from this fully parametric approach, and the implications of such priors for scaling relations formed from those masses. We show that the application of such fully parametric models of the ICM naturally imposes a prior on the slopes of the derived scaling relations, favoring the self-similar model, and argue that this prior may be influential in practice. In contrast, this bias does not exist for techniques which adopt an explicit prior on the form of the mass profile but describe the ICM non-parametrically. Constraints on the slope of the cluster mass-temperature relation in the literature show a separation based the approach employed, with the results from fully parametric ICM modeling clustering nearer the self-similar value. Given that a primary goal of scaling relation analyses is to test the self-similar model, the application of methods subject to strong, implicit priors should be avoided. Alternative methods and best practices are discussed.

  16. Surface Rupture Effects on Earthquake Moment-Area Scaling Relations (United States)

    Luo, Yingdi; Ampuero, Jean-Paul; Miyakoshi, Ken; Irikura, Kojiro


    Empirical earthquake scaling relations play a central role in fundamental studies of earthquake physics and in current practice of earthquake hazard assessment, and are being refined by advances in earthquake source analysis. A scaling relation between seismic moment ( M 0) and rupture area ( A) currently in use for ground motion prediction in Japan features a transition regime of the form M 0- A 2, between the well-recognized small (self-similar) and very large (W-model) earthquake regimes, which has counter-intuitive attributes and uncertain theoretical underpinnings. Here, we investigate the mechanical origin of this transition regime via earthquake cycle simulations, analytical dislocation models and numerical crack models on strike-slip faults. We find that, even if stress drop is assumed constant, the properties of the transition regime are controlled by surface rupture effects, comprising an effective rupture elongation along-dip due to a mirror effect and systematic changes of the shape factor relating slip to stress drop. Based on this physical insight, we propose a simplified formula to account for these effects in M 0- A scaling relations for strike-slip earthquakes.


    Black, S. H.; Gerhardt, Philipp


    Black, S. H. (The University of Michigan, Ann Arbor) and Philipp Gerhardt. Permeability of bacterial spores. I. Characterization of glucose uptake. J. Bacteriol. 82:743–749. 1961.—The total uptake of glucose by masses of clean, dormant spores was measured to assess their permeability. After correction for intercellular space, packed spores of Bacillus cereus strain terminalis were found in 87 determinations to be permeated by glucose to 40% of their weight. The glucose uptake was relatively independent of environmental variables, and thus was concluded to occur principally through a process of passive diffusion. PMID:13869665

  18. Scaling Relations of Starburst-driven Galactic Winds (United States)

    Tanner, Ryan; Cecil, Gerald; Heitsch, Fabian


    Using synthetic absorption lines generated from 3D hydrodynamical simulations, we explore how the velocity of a starburst-driven galactic wind correlates with the star formation rate (SFR) and SFR density. We find strong correlations for neutral and low ionized gas, but no correlation for highly ionized gas. The correlations for neutral and low ionized gas only hold for SFRs below a critical limit set by the mass loading of the starburst, above which point the scaling relations flatten abruptly. Below this point the scaling relations depend on the temperature regime being probed by the absorption line, not on the mass loading. The exact scaling relation depends on whether the maximum or mean velocity of the absorption line is used. We find that the outflow velocity of neutral gas can be up to five times lower than the average velocity of ionized gas, with the velocity difference increasing for higher ionization states. Furthermore, the velocity difference depends on both the SFR and mass loading of the starburst. Thus, absorption lines of neutral or low ionized gas cannot easily be used as a proxy for the outflow velocity of the hot gas.

  19. Large scale obscuration and related climate effects open literature bibliography

    Energy Technology Data Exchange (ETDEWEB)

    Russell, N.A.; Geitgey, J.; Behl, Y.K.; Zak, B.D.


    Large scale obscuration and related climate effects of nuclear detonations first became a matter of concern in connection with the so-called ``Nuclear Winter Controversy`` in the early 1980`s. Since then, the world has changed. Nevertheless, concern remains about the atmospheric effects of nuclear detonations, but the source of concern has shifted. Now it focuses less on global, and more on regional effects and their resulting impacts on the performance of electro-optical and other defense-related systems. This bibliography reflects the modified interest.

  20. Effect of wettability on scale-up of multiphase flow from core-scale to reservoir fine-grid-scale

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Y.C.; Mani, V.; Mohanty, K.K. [Univ. of Houston, TX (United States)


    Typical field simulation grid-blocks are internally heterogeneous. The objective of this work is to study how the wettability of the rock affects its scale-up of multiphase flow properties from core-scale to fine-grid reservoir simulation scale ({approximately} 10{prime} x 10{prime} x 5{prime}). Reservoir models need another level of upscaling to coarse-grid simulation scale, which is not addressed here. Heterogeneity is modeled here as a correlated random field parameterized in terms of its variance and two-point variogram. Variogram models of both finite (spherical) and infinite (fractal) correlation length are included as special cases. Local core-scale porosity, permeability, capillary pressure function, relative permeability functions, and initial water saturation are assumed to be correlated. Water injection is simulated and effective flow properties and flow equations are calculated. For strongly water-wet media, capillarity has a stabilizing/homogenizing effect on multiphase flow. For small variance in permeability, and for small correlation length, effective relative permeability can be described by capillary equilibrium models. At higher variance and moderate correlation length, the average flow can be described by a dynamic relative permeability. As the oil wettability increases, the capillary stabilizing effect decreases and the deviation from this average flow increases. For fractal fields with large variance in permeability, effective relative permeability is not adequate in describing the flow.

  1. Changes in Permeability Produced By Distant Earthquakes (United States)

    Manga, M.; Wang, C. Y.; Shi, Z.


    Oscillations in stress, such as those created by earthquakes, can increase permeability and fluid mobility in geologic media. In natural systems, strain amplitudes as small as 10-6 can increase discharge in streams and springs, change the water level of wells, and enhance production from petroleum reservoirs. Enhanced permeability typically recovers to pre-stimulated values over a period of months to years. This presentation will review some of the observations that indicate that dynamic stresses produced by seismic waves change permeability. We use the response of a set of wells distributed throughout China to multiple large earthquakes to probe the relationship between earthquake-generated stresses and water-level changes in wells. We find that dynamic stresses dominate the responses at distances more than 1 fault length from the earthquake and that permeability changes may explain the water level changes. Regions with high deformation rates are most sensitive to seismic waves. We also consider the response of a large alluvial fan in Taiwan to the 1999 M7.5 Chi-Chi earthquake where there were sustained changes in groundwater temperature after the earthquake. Using groundwater flow models, we infer that permeability increased by an order of magnitude over horizontal scales of tens of km, and vertical scales of several km. Permeability returned to the pre-earthquake value over many months. As much as half the total transport in the fan occurs during the short time periods with enhanced permeability.

  2. Permeability evolution due to dissolution and precipitation of carbonates using reactive transport modeling in pore networks (United States)

    Nogues, Juan P.; Fitts, Jeffrey P.; Celia, Michael A.; Peters, Catherine A.


    A reactive transport model was developed to simulate reaction of carbonates within a pore network for the high-pressure CO2-acidified conditions relevant to geological carbon sequestration. The pore network was based on a synthetic oolithic dolostone. Simulation results produced insights that can inform continuum-scale models regarding reaction-induced changes in permeability and porosity. As expected, permeability increased extensively with dissolution caused by high concentrations of carbonic acid, but neither pH nor calcite saturation state alone was a good predictor of the effects, as may sometimes be the case. Complex temporal evolutions of interstitial brine chemistry and network structure led to the counterintuitive finding that a far-from-equilibrium solution produced less permeability change than a nearer-to-equilibrium solution at the same pH. This was explained by the pH buffering that increased carbonate ion concentration and inhibited further reaction. Simulations of different flow conditions produced a nonunique set of permeability-porosity relationships. Diffusive-dominated systems caused dissolution to be localized near the inlet, leading to substantial porosity change but relatively small permeability change. For the same extent of porosity change caused from advective transport, the domain changed uniformly, leading to a large permeability change. Regarding precipitation, permeability changes happen much slower compared to dissolution-induced changes and small amounts of precipitation, even if located only near the inlet, can lead to large changes in permeability. Exponent values for a power law that relates changes in permeability and porosity ranged from 2 to 10, but a value of 6 held constant when conditions led to uniform changes throughout the domain.

  3. New scaling relation for information transfer in biological networks (United States)

    Kim, Hyunju; Davies, Paul; Walker, Sara Imari


    We quantify characteristics of the informational architecture of two representative biological networks: the Boolean network model for the cell-cycle regulatory network of the fission yeast Schizosaccharomyces pombe (Davidich et al. 2008 PLoS ONE 3, e1672 (doi:10.1371/journal.pone.0001672)) and that of the budding yeast Saccharomyces cerevisiae (Li et al. 2004 Proc. Natl Acad. Sci. USA 101, 4781–4786 (doi:10.1073/pnas.0305937101)). We compare our results for these biological networks with the same analysis performed on ensembles of two different types of random networks: Erdös–Rényi and scale-free. We show that both biological networks share features in common that are not shared by either random network ensemble. In particular, the biological networks in our study process more information than the random networks on average. Both biological networks also exhibit a scaling relation in information transferred between nodes that distinguishes them from random, where the biological networks stand out as distinct even when compared with random networks that share important topological properties, such as degree distribution, with the biological network. We show that the most biologically distinct regime of this scaling relation is associated with a subset of control nodes that regulate the dynamics and function of each respective biological network. Information processing in biological networks is therefore interpreted as an emergent property of topology (causal structure) and dynamics (function). Our results demonstrate quantitatively how the informational architecture of biologically evolved networks can distinguish them from other classes of network architecture that do not share the same informational properties. PMID:26701883

  4. Pressure sensitivity of low permeability sandstones (United States)

    Kilmer, N.H.; Morrow, N.R.; Pitman, J.K.


    Detailed core analysis has been carried out on 32 tight sandstones with permeabilities ranging over four orders of magnitude (0.0002 to 4.8 mD at 5000 psi confining pressure). Relationships between gas permeability and net confining pressure were measured for cycles of loading and unloading. For some samples, permeabilities were measured both along and across bedding planes. Large variations in stress sensitivity of permeability were observed from one sample to another. The ratio of permeability at a nominal confining pressure of 500 psi to that at 5000 psi was used to define a stress sensitivity ratio. For a given sample, confining pressure vs permeability followed a linear log-log relationship, the slope of which provided an index of pressure sensitivity. This index, as obtained for first unloading data, was used in testing relationships between stress sensitivity and other measured rock properties. Pressure sensitivity tended to increase with increase in carbonate content and depth, and with decrease in porosity, permeability and sodium feldspar. However, scatter in these relationships increased as permeability decreased. Tests for correlations between pressure sensitivity and various linear combinations of variables are reported. Details of pore structure related to diagenetic changes appears to be of much greater significance to pressure sensitivity than mineral composition. ?? 1987.

  5. Gas and Water Permeability of Concrete

    Energy Technology Data Exchange (ETDEWEB)

    Villar, M. V.; Martin, P. L.; Romero, F. J.; Gutierrez-Rodirgo, V.; Barcala, J. M.


    The gas pressure of concrete samples was measured in an unsteady-state equipment working under low injection pressures and in a newly fine tuned steady-state setup working under different pressures. These measurements allowed the estimation of the intrinsic and relative gas permeability of the concrete and of the effect of boundary conditions on them. Permeability decreased with water content, but it was also greatly affected by the hydraulic history of concrete, i.e. if it had been previously dried or wetted. In particular, and for a given degree of saturation, the gas permeability of concrete previously saturated was lower than if the concrete had been just air dried or saturated after air drying. In any case, the gas permeability was about two orders of magnitude higher than the liquid water permeability (10-16 vs. 10-18 m2), probably due to the chemical reactions taking place during saturation (carbonation). The relative gas permeability of concrete increased sharply for water degrees of saturation smaller than 50%. The boundary conditions also affected the gas permeability, which seemed to be mostly conditioned by the back pressure and the confining pressure, increasing as the former increased and decreasing as the latter increased, i.e. decreasing as the effective pressure increased. Overall the increase of pressure head or injection pressure implied a decrease in gas permeability. External,microcracking during air-drying could not be ruled out as responsible for the decrease of permeability with confining pressure. The apparent permeability obtained applying the Klinkenberg method for a given effective pressure was only slightly smaller than the average of all the values measured for the same confining pressure range. For this reason it is considered that the Klinkenberg effect was not relevant in the range of pressures applied. (Author) 37 refs.

  6. Evaluating Permeability Enchancement Using Electrical Techniques

    Energy Technology Data Exchange (ETDEWEB)

    John W. Pritchett


    Enhanced Geothermal Systems (EGS) development projects involve the artificial stimulation of relatively impermeable high-temperature underground regions (at depths of 2-4 kilometers or more) to create sufficient permeability to permit underground fluid circulation, so that hot water can be withdrawn from production wells and used to generate electric power. Several major research projects of this general type have been undertaken in the past in New Mexico (Fenton Hill), Europe, Japan and Australia. Recent U.S. activities along these lines focus mainly on stimulating peripheral areas of existing operating hydrothermal fields rather than on fresh 'greenfield' sites, but the long-term objective of the Department of Energy's EGS program is the development of large-scale power projects based on EGS technology (MIT, 2006; NREL, 2008). Usually, stimulation is accomplished by injecting water into a well at high pressure, enhancing permeability by the creation and propagation of fractures in the surrounding rock (a process known as 'hydrofracturing'). Beyond just a motivation, low initial system permeability is also an essential prerequisite to hydrofracturing. If the formation permeability is too high, excessive fluid losses will preclude the buildup of sufficient pressure to fracture rock. In practical situations, the actual result of injection is frequently to re-open pre-existing hydrothermally-mineralized fractures, rather than to create completely new fractures by rupturing intact rock. Pre-existing fractures can often be opened using injection pressures in the range 5-20 MPa. Creation of completely new fractures will usually require pressures that are several times higher. It is preferable to undertake development projects of this type in regions where tectonic conditions are conducive to shear failure, so that when pre-existing fractures are pressurized they will fail by shearing laterally. If this happens, the fracture will often stay open

  7. The Relation between Cosmological Redshift and Scale Factor for Photons (United States)

    Tian, Shuxun


    The cosmological constant problem has become one of the most important ones in modern cosmology. In this paper, we try to construct a model that can avoid the cosmological constant problem and have the potential to explain the apparent late-time accelerating expansion of the universe in both luminosity distance and angular diameter distance measurement channels. In our model, the core is to modify the relation between cosmological redshift and scale factor for photons. We point out three ways to test our hypothesis: the supernova time dilation; the gravitational waves and its electromagnetic counterparts emitted by the binary neutron star systems; and the Sandage-Loeb effect. All of this method is feasible now or in the near future.

  8. Relating the CMSSM and SUGRA models with GUT scale and Super-GUT scale Supersymmetry Breaking

    CERN Document Server

    Dudas, Emilian; Mustafayev, Azar; Olive, Keith A.


    While the constrained minimal supersymmetric standard model (CMSSM) with universal gaugino masses, $m_{1/2}$, scalar masses, $m_0$, and A-terms, $A_0$, defined at some high energy scale (usually taken to be the GUT scale) is motivated by general features of supergravity models, it does not carry all of the constraints imposed by minimal supergravity (mSUGRA). In particular, the CMSSM does not impose a relation between the trilinear and bilinear soft supersymmetry breaking terms, $B_0 = A_0 - m_0$, nor does it impose the relation between the soft scalar masses and the gravitino mass, $m_0 = m_{3/2}$. As a consequence, $\\tan \\beta$ is computed given values of the other CMSSM input parameters. By considering a Giudice-Masiero (GM) extension to mSUGRA, one can introduce new parameters to the K\\"ahler potential which are associated with the Higgs sector and recover many of the standard CMSSM predictions. However, depending on the value of $A_0$, one may have a gravitino or a neutralino dark matter candidate. We al...

  9. Permeable pavement study (Edison) (United States)

    U.S. Environmental Protection Agency — While permeable pavement is increasingly being used to control stormwater runoff, field-based, side-by-side investigations on the effects different pavement types...

  10. Permeability of displaced fractures (United States)

    Kluge, Christian; Milsch, Harald; Blöcher, Guido


    Flow along fractures or in fissured systems becomes increasingly important in the context of Enhanced Geothermal Systems (EGS), shale gas recovery or nuclear waste deposit. Commonly, the permeability of fractures is approximated using the Hagen-Poiseuille solution of Navier Stokes equation. Furthermore, the flow in fractures is assumed to be laminar flow between two parallel plates and the cubic law for calculating the velocity field is applied. It is a well-known fact, that fracture flow is strongly influenced by the fracture surface roughness and the shear displacement along the fracture plane. Therefore, a numerical approach was developed which calculates the flow pattern within a fracture-matrix system. The flow in the fracture is described by a free fluid flow and the flow in the matrix is assumed to be laminar and therefore validates Darcy's law. The presented approach can be applied for artificially generated fractures or real fractures measured by surface scanning. Artificial fracture surfaces are generated using the power spectral density of the surface height random process with a spectral exponent to define roughness. For calculating the permeability of such fracture-matrix systems the mean fracture aperture, the shear displacement and the surface roughness are considered by use of a 3D numerical simulator. By use of this approach correlation between shear displacement and mean aperture, shear displacement and permeability, as well as surface roughness and permeability can be obtained. Furthermore, the intrinsic measured permeability presents a combination of matrix and fracture permeability. The presented approach allows the separation and quantification of the absolute magnitudes of the matrix and the fracture permeability and the permeability of displaced fractures can be calculated. The numerical approach which is a 3D numerical simulation of the fracture-matrix system can be applied for artificial as well as real systems.

  11. Connectivity, formation factor and permeability of 2D fracture network (United States)

    Tang, Y. B.; Li, M.; Li, X. F.


    The purpose of this paper is to investigate the effects of fracture connectivity and length distributions on the electrical formation factor, F, of random fracture network using percolation theory. We assumed that the matrix was homogeneous and low-permeable, but the connectivity and length distributions of fracture system were randomly variable. F of fracture network is analyzed via finite element method. The main result is that: different from the classical percolation ;universal; power law for porous-type rocks, F of fracture network obeys a normalized ;universal; scaling relation using the length-scale / L ( is fracture mean length, and L is the domain size). Our proposed formation factor model, derived from the normalized ;universal; scaling relationship, is valid in fracture network with constant fracture length and length distributions, showing that the normalized ;universal; scaling law is independent of fracture patterns. The normalized scaling relation is also successfully used to derive the permeability model of 2D random fracture network using the previously published dataset, which obtained better fitting results than before.

  12. Effect of temperature on sandstone permeability

    DEFF Research Database (Denmark)

    Rosenbrand, Esther; Kjøller, Claus

    with the Kozeny equation and the Klinkenberg procedure. Both methods overestimated the measured brine permeability; this suggests that additional factors, possibly related to clay morphology, contributed to a lower brine permeability. Thermal expansion would have a negligible effect on permeability as estimated...... interaction forces. Quantitative analysis of images, in which mineralogy was mapped based on backscatter electron intensity in combination with energy dispersive X-ray analysis by using the QEMSCAN® system, was used to compare a tested sample to an untested Berea sandstone sample. During the experiment...

  13. Large Scale Obscuration and Related Climate Effects Workshop: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Zak, B.D.; Russell, N.A.; Church, H.W.; Einfeld, W.; Yoon, D.; Behl, Y.K. [eds.


    A Workshop on Large Scale Obsurcation and Related Climate Effects was held 29--31 January, 1992, in Albuquerque, New Mexico. The objectives of the workshop were: to determine through the use of expert judgement the current state of understanding of regional and global obscuration and related climate effects associated with nuclear weapons detonations; to estimate how large the uncertainties are in the parameters associated with these phenomena (given specific scenarios); to evaluate the impact of these uncertainties on obscuration predictions; and to develop an approach for the prioritization of further work on newly-available data sets to reduce the uncertainties. The workshop consisted of formal presentations by the 35 participants, and subsequent topical working sessions on: the source term; aerosol optical properties; atmospheric processes; and electro-optical systems performance and climatic impacts. Summaries of the conclusions reached in the working sessions are presented in the body of the report. Copies of the transparencies shown as part of each formal presentation are contained in the appendices (microfiche).

  14. Scaling Relations for Acidity and Reactivity of Zeolites (United States)


    Zeolites are widely applied as solid acid catalysts in various technological processes. In this work we have computationally investigated how catalytic reactivity scales with acidity for a range of zeolites with different topologies and chemical compositions. We found that straightforward correlations are limited to zeolites with the same topology. The adsorption energies of bases such as carbon monoxide (CO), acetonitrile (CH3CN), ammonia (NH3), trimethylamine (N(CH3)3), and pyridine (C5H5N) give the same trend of acid strength for FAU zeolites with varying composition. Crystal orbital Hamilton populations (COHP) analysis provides a detailed molecular orbital picture of adsorbed base molecules on the Brønsted acid sites (BAS). Bonding is dominated by strong σ donation from guest molecules to the BAS for the adsorbed CO and CH3CN complexes. An electronic descriptor of acid strength is constructed based on the bond order calculations, which is an intrinsic parameter rather than adsorption energy that contains additional contributions due to secondary effects such as van der Waals interactions with the zeolite walls. The bond order parameter derived for the CH3CN adsorption complex represents a useful descriptor for the intrinsic acid strength of FAU zeolites. For FAU zeolites the activation energy for the conversion of π-adsorbed isobutene into alkoxy species correlates well with the acid strength determined by the NH3 adsorption energies. Other zeolites such as MFI and CHA do not follow the scaling relations obtained for FAU; we ascribe this to the different van der Waals interactions and steric effects induced by zeolite framework topology. PMID:29142616

  15. Fundametal Study On Permeability Pavement


    川口, 基広; 建部, 英博


    This study aimed at the thing which develops a water permeability pavement which improved a drainage pavement. Then it examined possibility of the permeability pavement which can secure water permeability and strength, which it uses water granulated iron-blast-furnace slag in subgrade roadbed and it makes an asphalt mixture mix a stainless steel fiber, to solve a problem of permeability pavement

  16. Relationship between statistical properties of permeability field and behavior of concentration in stationary fluid flow. (United States)

    Akhmetsafina, A.; Willmann, M.; Kinzelbach, W.


    In contemporary groundwater engineering heterogeneous aquifers with complex-structured permeability fields are of high interest. Heterogeneous fields create difficulties in up-scaling, increase the computation time, and may influence on selection of hydrodynamic model. A major problem us to relate permeability fields, flow and concentration behavior. Our overall goal is to investigate the correlation between permeability field and modifications of concentration. We consider binary fields, comprised of high-permeable and low permeable zones with a varying high permeability ratio. Low-permeable zones represent a matrix and high-permeable zones represent randomly distributed inclusions in the shape of discs. In this case percolation theory is applicable and connectivity can be defined accordingly. If the intensity of inclusions is high enough, permeable areas construct cluster, that provide main fluid flow and percolation exists. Such a critical intensity is unique and percolation occurs suddenly with intensity increasing through this threshold. We are interested in cases nearby the percolation threshold. Darcy velocity field becomes heterogeneous. Fast "channels" and almost immobile zones appear that allows us talking about dual media: dual-porosity, dual-permeability models for Darcy equation and multi-rate model for advection-dispersion equation. We assume a stationary flow in a rectangular 2D domain with first type boundary condition. Using the resulting velocity fields we solve the advection-diffusion equation with a unit pulse of concentration at the left border. Two singularities can be observed: fast channels lead to early first-arrival times of the concentration. Secondly, almost immobile zones collect concentration at first and then give it back into clear water flow causing anormal tailing of the BTC. This is the reason why separate transport up-scaling is needed. We calibrate multi-rate model's parameters responsible for early arrivals (ratio between

  17. Upscaling of permeability in Shale with Heterogeneous Kerogen Distribution (United States)

    Cao, G.; Lin, M.


    Apparent permeability is a vital parameter for accurate estimation of exploitable gas reserve in shale. In this paper, we introduce a new model to investigate multi-scale gas-transport phenomena in organic-rich-shale with heterogeneous kerogen distribution. The formulation is decomposed into two subdomains: kerogen and inorganic matrix. On the one hand, considering the molecular phenomena (slip and diffusive transport) is significant in kerogen for its enrichment of nanopores, we use pore-scale network model (PNM) to represent it and apply Javadpour's apparent permeability formula(2009) to calculate flow in the nanoscale throats. On the other hand, inorganic matrix, with relatively large pores, micro natural fractures and manual hydraulic fracturing cracks, its flow is approximate to Darcy, so we model it as continuum-scale models FVM. The two subdomains are coupled using mortars. Mortars are finite-element spaces employed to couple independent subdomains by ensuring interfacial pressures and fluxes are matched. Considering the local heterogeneities, kerogen is treated as several nanoporous organic material blocks randomly dispersed within the inorganic matrix. We study on four factors: the distribution of kerogen, the permeability of inorganic matrix (Ki), the magnitude of pressure, and the TOC of coupling model. The results are shown intuitively by APF (apparent permeability function) graph. We conclude that: (1) when Ki is greater than the Darcy permeability of kerogen, the APF graphs with different TOC and distribution have an intersection point, and this point is only decided by permeability of Ki and the pore size distribution of kerogen; (2) when pressure is close to or higher than the pressure of intersection point, the influence of heterogeneous distribution can be ignored, and the complex coupling model can instead by a simple equivalent model. This work is supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB

  18. Permeable pavement study (Edison) (United States)

    While permeable pavement is increasingly being used to control stormwater runoff, field-based, side-by-side investigations on the effects different pavement types have on nutrient concentrations present in stormwater runoff are limited. In 2009, the U.S. EPA constructed a 0.4-ha parking lot in Edison, New Jersey, that incorporated permeable interlocking concrete pavement (PICP), pervious concrete (PC), and porous asphalt (PA). Each permeable pavement type has four, 54.9-m2, lined sections that direct all infiltrate into 5.7-m3 tanks enabling complete volume collection and sampling. This paper highlights the results from a 12-month period when samples were collected from 13 rainfall/runoff events and analyzed for nitrogen species, orthophosphate, and organic carbon. Differences in infiltrate concentrations among the three permeable pavement types were assessed and compared with concentrations in rainwater samples and impervious asphalt runoff samples, which were collected as controls. Contrary to expectations based on the literature, the PA infiltrate had significantly larger total nitrogen (TN) concentrations than runoff and infiltrate from the other two permeable pavement types, indicating that nitrogen leached from materials in the PA strata. There was no significant difference in TN concentration between runoff and infiltrate from either PICP or PC, but TN in runoff was significantly larger than in the rainwater, suggesting meaningful inter-event dry de

  19. EFSA NDA Panel (EFSA Panel on Dietetic Products, Nutrition and Allergies), 2014. Scientific Opinion on the substantiation of a health claim related to a combination of diosmin, troxerutin and hesperidin and maintenance of normal venous-capillary permeability pursuant to Article 13(5) of Regulation

    DEFF Research Database (Denmark)

    Tetens, Inge


    claim related to a combination of diosmin, troxerutin and hesperidin and maintenance of normal venous-capillary permeability. The food that is a subject of the health claim, a combination of diosmin, troxerutin and hesperidin, is sufficiently characterised. The claimed effect, maintenance of normal...... the consumption of a combination of diosmin, troxerutin and hesperidin and the maintenance of normal venous-capillary permeability....

  20. Determination of glucose exchange rates and permeability of erythrocyte membrane in preeclampsia and subsequent oxidative stress-related protein damage using dynamic-19F-NMR. (United States)

    Dickinson, Elizabeth; Arnold, John R P; Fisher, Julie


    The cause of the pregnancy condition preeclampsia (PE) is thought to be endothelial dysfunction caused by oxidative stress. As abnormal glucose tolerance has also been associated with PE, we use a fluorinated-mimic of this metabolite to establish whether any oxidative damage to lipids and proteins in the erythrocyte membrane has increased cell membrane permeability. Data were acquired using 19 F Dynamic-NMR (DNMR) to measure exchange of 3-fluoro-3-deoxyglucose (3-FDG) across the membrane of erythrocytes from 10 pregnant women (5 healthy control women, and 5 from women suffering from PE). Magnetisation transfer was measured using the 1D selective inversion and 2D EXSY pulse sequences, over a range of time delays. Integrated intensities from these experiments were used in matrix diagonalisation to estimate the values of the rate constants of exchange and membrane permeability. No significant differences were observed for the rate of exchange of 3-FDG and membrane permeability between healthy pregnant women and those suffering from PE, leading us to conclude that no oxidative damage had occurred at this carrier-protein site in the membrane.

  1. Determination of glucose exchange rates and permeability of erythrocyte membrane in preeclampsia and subsequent oxidative stress-related protein damage using dynamic-{sup 19}F-NMR

    Energy Technology Data Exchange (ETDEWEB)

    Dickinson, Elizabeth, E-mail: [University of York, Department of Chemistry (United Kingdom); Arnold, John R. P. [Selby College (United Kingdom); Fisher, Julie [University of Leeds, School of Chemistry (United Kingdom)


    The cause of the pregnancy condition preeclampsia (PE) is thought to be endothelial dysfunction caused by oxidative stress. As abnormal glucose tolerance has also been associated with PE, we use a fluorinated-mimic of this metabolite to establish whether any oxidative damage to lipids and proteins in the erythrocyte membrane has increased cell membrane permeability. Data were acquired using {sup 19}F Dynamic-NMR (DNMR) to measure exchange of 3-fluoro-3-deoxyglucose (3-FDG) across the membrane of erythrocytes from 10 pregnant women (5 healthy control women, and 5 from women suffering from PE). Magnetisation transfer was measured using the 1D selective inversion and 2D EXSY pulse sequences, over a range of time delays. Integrated intensities from these experiments were used in matrix diagonalisation to estimate the values of the rate constants of exchange and membrane permeability. No significant differences were observed for the rate of exchange of 3-FDG and membrane permeability between healthy pregnant women and those suffering from PE, leading us to conclude that no oxidative damage had occurred at this carrier-protein site in the membrane.

  2. Biostable glucose permeable polymer

    DEFF Research Database (Denmark)


    A new biostable glucose permeable polymer has been developed which is useful, for example, in implantable glucose sensors. This biostable glucose permeable polymer has a number of advantageous characteristics and, for example, does not undergo hydrolytic cleavage and degradation, thereby providing...... a composition that facilitates long term sensor stability in vivo. The versatile characteristics of this polymer allow it to be used in a variety of contexts, for example to form the body of an implantable glucose sensor. The invention includes the polymer composition, sensor systems formed from this polymer...

  3. Development and Comparison of Techniques for Generating Permeability Maps using Independent Experimental Approaches (United States)

    Hingerl, Ferdinand; Romanenko, Konstantin; Pini, Ronny; Balcom, Bruce; Benson, Sally


    We have developed and evaluated methods for creating voxel-based 3D permeability maps of a heterogeneous sandstone sample using independent experimental data from single phase flow (Magnetic Resonance Imaging, MRI) and two-phase flow (X-ray Computed Tomography, CT) measurements. Fluid velocities computed from the generated permeability maps using computational fluid dynamics simulations fit measured velocities very well and significantly outperform empirical porosity-permeability relations, such as the Kozeny-Carman equation. Acquiring images on the meso-scale from porous rocks using MRI has till recently been a great challenge, due to short spin relaxation times and large field gradients within the sample. The combination of the 13-interval Alternating-Pulsed-Gradient Stimulated-Echo (APGSTE) scheme with three-dimensional Single Point Ramped Imaging with T1 Enhancement (SPRITE) - a technique recently developed at the UNB MRI Center - can overcome these challenges and enables obtaining quantitative 3 dimensional maps of porosities and fluid velocities. Using porosity and (single-phase) velocity maps from MRI and (multi-phase) saturation maps from CT measurements, we employed three different techniques to obtain permeability maps. In the first approach, we applied the Kozeny-Carman relationship to porosities measured using MRI. In the second approach, we computed permeabilities using a J-Leverett scaling method, which is based on saturation maps obtained from N2-H2O multi-phase experiments. The third set of permeabilities was generated using a new inverse iterative-updating technique, which is based on porosities and measured velocities obtained in single-phase flow experiments. The resulting three permeability maps provided then input for computational fluid dynamics simulations - employing the Stanford CFD code AD-GPRS - to generate velocity maps, which were compared to velocity maps measured by MRI. The J-Leveret scaling method and the iterative-updating method

  4. Regional scale ecological risk assessment: using the relative risk model

    National Research Council Canada - National Science Library

    Landis, Wayne G


    ...) in the performance of regional-scale ecological risk assessments. The initial chapters present the methodology and the critical nature of the interaction between risk assessors and decision makers...

  5. Permeability of Two Parachute Fabrics: Measurements, Modeling, and Application (United States)

    Cruz, Juan R.; O'Farrell, Clara; Hennings, Elsa; Runnells, Paul


    Two parachute fabrics, described by Parachute Industry Specifications PIA-C-7020D Type I and PIA-C-44378D Type I, were tested to obtain their permeabilities in air (i.e., flow-through volume of air per area per time) over the range of differential pressures from 0.146 psf (7 Pa) to 25 psf (1197 Pa). Both fabrics met their specification permeabilities at the standard differential pressure of 0.5 inch of water (2.60 psf, 124 Pa). The permeability results were transformed into an effective porosity for use in calculations related to parachutes. Models were created that related the effective porosity to the unit Reynolds number for each of the fabrics. As an application example, these models were used to calculate the total porosities for two geometrically-equivalent subscale Disk-Gap-Band (DGB) parachutes fabricated from each of the two fabrics, and tested at the same operating conditions in a wind tunnel. Using the calculated total porosities and the results of the wind tunnel tests, the drag coefficient of a geometrically-equivalent full-scale DGB operating on Mars was estimated.

  6. Permeability of Two Parachute Fabrics - Measurements, Modeling, and Application (United States)

    Cruz, Juan R.; O'Farrell, Clara; Hennings, Elsa; Runnells, Paul


    Two parachute fabrics, described by Parachute Industry Specifications PIA-C-7020D Type I and PIA-C-44378D Type I, were tested to obtain their permeabilities in air (i.e., flow-through volume of air per area per time) over the range of differential pressures from 0.146 psf (7 Pa) to 25 psf (1197 Pa). Both fabrics met their specification permeabilities at the standard differential pressure of 0.5 inch of water (2.60 psf, 124 Pa). The permeability results were transformed into an effective porosity for use in calculations related to parachutes. Models were created that related the effective porosity to the unit Reynolds number for each of the fabrics. As an application example, these models were used to calculate the total porosities for two geometrically-equivalent subscale Disk-Gap-Band (DGB) parachutes fabricated from each of the two fabrics, and tested at the same operating conditions in a wind tunnel. Using the calculated total porosities and the results of the wind tunnel tests, the drag coefficient of a geometrically-equivalent full-scale DGB operating on Mars was estimated.

  7. Variational calculation of the effective fluid permeability of heterogeneous media (United States)

    Hristopulos, Dionissios T.; Christakos, George


    We evaluate the effective permeability of heterogeneous media with Gaussian local permeability disorder using the replica-variational approach. We obtain integral equations that determine the effective permeability kernel, and we study specific cases that admit analytical solutions. Specifically, in the case of homogeneous disorder we obtain a variational estimate for the uniform effective permeability. We compare the results of our analytical calculations with experimental and numerical data. Finally, we model the behavior of the effective permeability in the preasymptotic regime by means of momentum filters. Explicit finite-size expressions are obtained in terms of a support function that increases monotonically with the ratio of the support scale over the correlation length of the disorder. It is found that the asymptotic effective permeability is approached at a slower rate than expected.

  8. Scaling relation for determining the critical threshold for continuum ...

    Indian Academy of Sciences (India)

    We study continuum percolation of overlapping circular discs of two sizes. We propose a phenomenological scaling equation for the increase in the effective size of the larger discs due to the presence of the smaller discs. The critical percolation threshold as a function of the ratio of sizes of discs, for different values of the ...

  9. Scaling relation for determining the critical threshold for continuum ...

    Indian Academy of Sciences (India)

    Abstract. We study continuum percolation of overlapping circular discs of two sizes. We propose a phenomenological scaling equation for the increase in the effective size of the larger discs due to the presence of the smaller discs. The critical percolation threshold as a function of the ratio of sizes of discs, for different values ...

  10. Quantifying Evaporation in a Permeable Pavement System ... (United States)

    Studies quantifying evaporation from permeable pavement systems are limited to a few laboratory studies and one field application. This research quantifies evaporation for a larger-scale field application by measuring the water balance from lined permeable pavement sections. The U.S. Environmental Protection Agency (USEPA) constructed a 0.4-ha parking lot in Edison, NJ, that incorporated three different permeable pavement types in the parking lanes – permeable interlocking concrete pavers (PICP), pervious concrete (PC), and porous asphalt (PA). An impermeable liner installed 0.4 m below the driving surface in four 11.6-m by 4.74-m sections per each pavement type captures all infiltrating water and routes it to collection tanks that can contain events up to 38 mm. Each section has a design impervious area to permeable pavement area ratio of 0.66:1. Pressure transducers installed in the underdrain collection tanks measured water level for 24 months. Level was converted to volume using depth-to-volume ratios for individual collection tanks. Using a water balance approach, the measured infiltrate volume was compared to rainfall volume on an event-basis to determine the rainfall retained in the pavement strata and underlying aggregate. Evaporation since the previous event created additional storage in the pavement and aggregate layers. Events were divided into three groups based on antecedent dry period (ADP) and three, four-month categories of potential e

  11. Development & Validation of a PTSD-Related Impairment Scale (United States)


    grooming (for example, showering, brushing teeth , etc). 0 1 2 3 4 5 6 75. I had trouble managing my medical care (for example, medications, doctors...controversies that should be incorporated into the content of scale items. Another important source of information was from veterans of various within the veteran population. This prevalence suggests the importance of analyzing other components that may also be associated with functional

  12. A Permeability-Porosity Relationship for Surface Deposition

    Energy Technology Data Exchange (ETDEWEB)

    Weir, G.J.; White, S.P.


    The changes to porosity and permeability resulting from surface deposition and early dissolution in an initial rhombohedral array of uniform spheres are calculated. Very rapid decreases of permeability result from early deposition, with 48% reduction predicted in permeability from 8% reduction in porosity. After deposition has caused about a 1% increase in the radii of the spherical array, relative permeability reductions vary approximately as the square of relative changes in porosity. These theoretical results are matched with experimental data of Ioti et al. and shown to be satisfactory in some cases, but for others, a more complex model of the porous medium is needed.

  13. Event-related alpha perturbations related to the scaling of steering wheel corrections. (United States)

    Brooks, Justin; Kerick, Scott


    Previously we derived a new measure relating the driver's steering wheel responses to the vehicle's heading error velocity. This measure, the relative steering wheel compensation (RSWC), changes at times coincident with an alerting stimulus, possibly representing shifts in control strategy as measured by a change in the gain between visual input and motor output. In the present study, we sought to further validate this novel measure by determining the relationship between the RSWC and electroencephalogram (EEG) activity in brain regions associated with sensorimotor transformation processes. These areas have been shown to exhibit event-related spectral perturbation (ERSP) in the alpha frequency band that occurs with the onset of corrective steering wheel maneuvers in response to vehicle perturbations. We hypothesized that these regions would show differential alpha activity depending on whether the RSWC was high or low, reflecting changes in gain between visual input and motor output. Interestingly, we find that low RSWC is associated with significantly less peak desynchronization than larger RSWC. In addition we demonstrate that these differences are not attributable to the amount the steering wheel is turned nor the heading error velocity independently. Collectively these results suggest that neural activity in these sensorimotor regions scales with alertness and may represent differential utilization of multisensory information to control the steering wheel. Published by Elsevier Inc.

  14. Two mutations in mitochondrial ATP6 gene of ATP synthase, related to human cancer, affect ROS, calcium homeostasis and mitochondrial permeability transition in yeast. (United States)

    Niedzwiecka, Katarzyna; Tisi, Renata; Penna, Sara; Lichocka, Malgorzata; Plochocka, Danuta; Kucharczyk, Roza


    The relevance of mitochondrial DNA (mtDNA) mutations in cancer process is still unknown. Since the mutagenesis of mitochondrial genome in mammals is not possible yet, we have exploited budding yeast S. cerevisiae as a model to study the effects of tumor-associated mutations in the mitochondrial MTATP6 gene, encoding subunit 6 of ATP synthase, on the energy metabolism. We previously reported that four mutations in this gene have a limited impact on the production of cellular energy. Here we show that two mutations, Atp6-P163S and Atp6-K90E (human MTATP6-P136S and MTATP6-K64E, found in prostate and thyroid cancer samples, respectively), increase sensitivity of yeast cells both to compounds inducing oxidative stress and to high concentrations of calcium ions in the medium, when Om45p, the component of porin complex in outer mitochondrial membrane (OM), was fused to GFP. In OM45-GFP background, these mutations affect the activation of yeast permeability transition pore (yPTP, also called YMUC, yeast mitochondrial unspecific channel) upon calcium induction. Moreover, we show that calcium addition to isolated mitochondria heavily induced the formation of ATP synthase dimers and oligomers, recently proposed to form the core of PTP, which was slower in the mutants. We show the genetic evidence for involvement of mitochondrial ATP synthase in calcium homeostasis and permeability transition in yeast. This paper is a first to show, although in yeast model organism, that mitochondrial ATP synthase mutations, which accumulate during carcinogenesis process, may be significant for cancer cell escape from apoptosis. Copyright © 2017 Elsevier B.V. All rights reserved.


    Directory of Open Access Journals (Sweden)

    Alexander V. Boichenko


    Full Text Available This article analyzes the main methods of scalingdatabases (replication, sharding and their supportat the popular relational databases and NoSQLsolutions with different data models: document-oriented, key-value, column-oriented and graph.The article presents an algorithm for the dynamicscaling of a relational database (DB, that takesinto account the specifics of the different types of logic database model. This article was prepared with the support of RFBR (grant № 13-07-00749.

  16. Revisiting Scaling Relations for Giant Radio Halos in Galaxy Clusters (United States)

    Cassano, R.; Ettori, S.; Brunetti, G.; Giacintucci, S.; Pratt, G. W.; Venturi, T.; Kale, R.; Dolag, K.; Markevitch, Maxim L.


    Many galaxy clusters host megaparsec-scale radio halos, generated by ultrarelativistic electrons in the magnetized intracluster medium. Correlations between the synchrotron power of radio halos and the thermal properties of the hosting clusters were established in the last decade, including the connection between the presence of a halo and cluster mergers. The X-ray luminosity and redshift-limited Extended GMRT Radio Halo Survey provides a rich and unique dataset for statistical studies of the halos. We uniformly analyze the radio and X-ray data for the GMRT cluster sample, and use the new Planck Sunyaev-Zel'dovich (SZ) catalog to revisit the correlations between the power of radio halos and the thermal properties of galaxy clusters. We find that the radio power at 1.4 GHz scales with the cluster X-ray (0.1-2.4 keV) luminosity computed within R(sub 500) as P(sub 1.4) approx. L(2.1+/-0.2) - 500). Our bigger and more homogenous sample confirms that the X-ray luminous (L(sub 500) > 5 × 10(exp 44) erg/s)) clusters branch into two populations-radio halos lie on the correlation, while clusters without radio halos have their radio upper limits well below that correlation. This bimodality remains if we excise cool cores from the X-ray luminosities. We also find that P(sub 1.4) scales with the cluster integrated SZ signal within R(sub 500), measured by Planck, as P(sub 1.4) approx. Y(2.05+/-0.28) - 500), in line with previous findings. However, contrary to previous studies that were limited by incompleteness and small sample size, we find that "SZ-luminous" Y(sub 500) > 6×10(exp -5) Mpc(exp 2) clusters show a bimodal behavior for the presence of radio halos, similar to that in the radio-X-ray diagram. Bimodality of both correlations can be traced to clusters dynamics, with radio halos found exclusively in merging clusters. These results confirm the key role of mergers for the origin of giant radio halos, suggesting that they trigger the relativistic particle acceleration.

  17. Galaxy metallicity scaling relations in the EAGLE simulations (United States)

    De Rossi, María Emilia; Bower, Richard G.; Font, Andreea S.; Schaye, Joop; Theuns, Tom


    We quantify the correlations between gas-phase and stellar metallicities and global properties of galaxies, such as stellar mass, halo mass, age and gas fraction, in the Evolution and Assembly of GaLaxies and their Environments suite of cosmological hydrodynamical simulations. The slope of the correlation between stellar mass and metallicity of star-forming (SF) gas (M*-ZSF,gas relation) depends somewhat on resolution, with the higher resolution run reproducing a steeper slope. This simulation predicts a non-zero metallicity evolution, increasing by ≈0.5 dex at ∼109 M⊙ since z = 3. The simulated relation between stellar mass, metallicity and star formation rate at z ≲ 5 agrees remarkably well with the observed fundamental metallicity relation. At M* ≲ 1010.3 M⊙ and fixed stellar mass, higher metallicities are associated with lower specific star formation rates, lower gas fractions and older stellar populations. On the other hand, at higher M*, there is a hint of an inversion of the dependence of metallicity on these parameters. The fundamental parameter that best correlates with the metal content, in the simulations, is the gas fraction. The simulated gas fraction-metallicity relation exhibits small scatter and does not evolve significantly since z = 3. In order to better understand the origin of these correlations, we analyse a set of lower resolution simulations in which feedback parameters are varied. We find that the slope of the simulated M*-ZSF,gas relation is mostly determined by stellar feedback at low stellar masses (M* ≲ 1010 M⊙), and at high masses (M* ≳ 1010 M⊙) by the feedback from active galactic nuclei.

  18. Application of relative permeability modifier additives to reduce water production in different formations; Aplicacao de aditivos modificadores de permeabilidade relativa para reducao da producao de agua em diferentes formacoes

    Energy Technology Data Exchange (ETDEWEB)

    Melo, Ricardo C.B.; Torres, Ricardo S.; Pedrosa Junior, Helio; Dean, Gregory [BJ Services do Brasil Ltda., RJ (Brazil)


    Today most oil companies would be better described as water companies. Total worldwide oil production averages some 75 million barrels per day and, while estimates vary, this is associated with the production of 300 - 400 million barrels of water per day. These values of approximately 5 - 6 barrels of water for every barrel of oil are quite conservative. In the United States, where many fields are depleted, the ratio of water-to-oil production is closer to 9 to 1. In some areas around the world, fields remain on production when the ratio is as high as 48 to 1. Numerous strategies, both mechanical and chemical, have been employed over the years in attempts to achieve reduction in water production. Simple shut-off techniques, using cement, mechanical plugs and cross-linked gels have been widely used. Exotic materials such as DPR (disproportionate permeability reducers) and or new generation of relative permeability modifiers (RPM) have been applied in radial treatments with varying degrees of success. Most recently 'Conformance Fracturing' operations have increased substantially in mature fields as the synergistic effect obtained by adding a RPM to a fracturing fluid have produced increased oil production with reduced water cut in one step, consequently eliminating the cost of additional water shut off treatment later on. This paper presents laboratory testing and worldwide case histories of applications of various RPM materials, at different permeability and temperatures. The paper also describes technical design and operational methodology that we believe to have a significant impact in the development strategies of many fields worldwide. (author)

  19. Permeability measuremens of brazilian Eucalyptus

    Directory of Open Access Journals (Sweden)

    Marcio Rogério da Silva


    Full Text Available The permeability of Brazilian Eucalyptus grandis and Eucalyptus citriodora wood was measured in a custom build gas analysis chamber in order to determine which species could be successfully treated with preservatives. Liquid permeability was tested using an emulsion of Neen oil and a control of distillated water. Air was used to test the gas phase permeability. For both Eucalyptus grandis and Eucalyptus citriodora, the longitudinal permeability of gas was shown to be about twice as great as the liquid phase permeability. No radial permeability was observed for either wood. The permeability of air and water through the sapwood of Eucalyptus grandis was greater than that through the sapwood of Eucalyptus citriodora. The permeability of neen oil preservative through the sapwood of Eucalyptus grandis was also greater than through the sapwood of E. Citradora, but the difference was not statistically significant. Scanning Electron Microscopy images showed that the distribution and obstruction in the vessels could be correlated with observed permeability properties. Irrespective of the causes of differences in permeability between the species, the fluid phase flux through the sapwood of both species was significant, indicating that both Eucalyptus grandis and Eucalyptus citriodora could be successfully treated with wood preservative.

  20. Super Clausius-Clapeyron scaling of extreme hourly precipitation and its relation to large-scale atmospheric conditions (United States)

    Lenderink, Geert; Barbero, Renaud; Loriaux, Jessica; Fowler, Hayley


    Present-day precipitation-temperature scaling relations indicate that hourly precipitation extremes may have a response to warming exceeding the Clausius-Clapeyron (CC) relation; for The Netherlands the dependency on surface dew point temperature follows two times the CC relation corresponding to 14 % per degree. Our hypothesis - as supported by a simple physical argument presented here - is that this 2CC behaviour arises from the physics of convective clouds. So, we think that this response is due to local feedbacks related to the convective activity, while other large scale atmospheric forcing conditions remain similar except for the higher temperature (approximately uniform warming with height) and absolute humidity (corresponding to the assumption of unchanged relative humidity). To test this hypothesis, we analysed the large-scale atmospheric conditions accompanying summertime afternoon precipitation events using surface observations combined with a regional re-analysis for the data in The Netherlands. Events are precipitation measurements clustered in time and space derived from approximately 30 automatic weather stations. The hourly peak intensities of these events again reveal a 2CC scaling with the surface dew point temperature. The temperature excess of moist updrafts initialized at the surface and the maximum cloud depth are clear functions of surface dew point temperature, confirming the key role of surface humidity on convective activity. Almost no differences in relative humidity and the dry temperature lapse rate were found across the dew point temperature range, supporting our theory that 2CC scaling is mainly due to the response of convection to increases in near surface humidity, while other atmospheric conditions remain similar. Additionally, hourly precipitation extremes are on average accompanied by substantial large-scale upward motions and therefore large-scale moisture convergence, which appears to accelerate with surface dew point. This

  1. Rough and partially-cemented fracture permeability (United States)

    Landry, C. J.; Eichhubl, P.; Prodanovic, M.


    Numerical studies of mass transport in fractured rock, such as discrete fracture network models, use models to assign estimates of permeability to individual fractures. These fracture permeability models typically employ statistical moments of the fracture aperture distribution to estimate permeability. Although it is known that these fracture permeability models are in error, the quantification of this error is limited. We use a digital rock physics workflow to quantify this error in four fracture samples, a barren artificially-induced fracture in sandstone, a calcite-lined fracture sampled from outcrop, and two quartz-bridged fractures sampled from reservoir core. Each of the fracture samples is imaged using three-dimensional x-ray computed microtomography. The images are then processed, segmented and used in a lattice-Boltzmann-method-based flow simulation. We also vary the kinematic apertures of the barren and calcite-lined fractures through digital dilatation and closure in order to investigate sensitivity to the relative fracture roughness. We define the scalar error, F, between the actual permeability determined from simulation, kLB, and that predicted using the fracture permeability model of Zimmerman and Bodvarsson (1996), kZB, as, F±1=kZB/kLB. Although the pore space shape of the fractures appears quite different, the scalar error as a function of relative roughness is found to be similar for all fracture samples investigated, with a maximum of approximately 2. Considering two-dimensional cross-sections of fractures are more readily available than three-dimensional images we then plot the scalar error as a function of relative roughness and the number of observations measured from two-dimensional images (width of fracture analyzed). In general, the rougher the fracture, the greater the number of observations that are required to define the statistical moment inputs for the fracture permeability model. We use these results to approximate the width of the

  2. A criterion-related validity study of the nursing-care dependency (NCD) scale

    NARCIS (Netherlands)

    Dijkstra, A.; Buist, G.; Dassen, Th.W.N.

    The purpose of this study was to examine some aspects of the criterion-related validity of the Nursing-Care Dependency (NCD) scale. This 15-item counting scale has recently been developed for assessing the care dependency of demented or mentally handicapped in-patients. Its criterion-related

  3. Psychometric properties of the satisfaction with food-related Life Scale

    DEFF Research Database (Denmark)

    Schnettler, Berta; Miranda, Horacio; Sepúlveda, José


    Objective: To evaluate the psychometric properties of the Satisfaction with Food-related Life (SWFL) scale and its relation to the Satisfaction with Life Scale (SWLS) in southern Chile. Methods: A survey was applied to a sample of 316 persons in the principal cities of southern Chile distributed ...

  4. Low Permeability Polyimide Insulation Project (United States)

    National Aeronautics and Space Administration — Resodyn Technologies proposes a new technology that enables the application of polyimide based cryogenic insulation with low hydrogen permeability. This effort...

  5. Discriminant and criterion-related validity of a relative deprivation scale in a merger and acquisition context. (United States)

    Lee, Dongseop; Cho, Bongsoon; Seo, Jeongil; Lee, Khan-Pyo; Choi, Jang-Ho


    This study examined the discriminant and criterion-related validity of the Relative Deprivation Scale. The data were collected from 151 Korean employees who had recently experienced a merger and acquisition. The results of confirmatory factor analysis revealed that the two dimensions of relative deprivation (egoistic and fraternal relative deprivation) are clearly distinguishable from other conceptually related variables, such as negative affectivity, resistance to change, overall job dissatisfaction, and distributive justice. In addition, egoistic relative deprivation made a unique incremental contribution to explaining employee turnover intention beyond the contribution of conceptually related variables, while fraternal relative deprivation did not.

  6. Nano scale devices: Fabrication, actuation, and related fluidic dynamics (United States)

    Jing, Hao

    cilia beating through the use of magnetic nanowires. We apply our custom magnetic system, 3DFM, to drive these magnetic nanowires rotating with desired patterns and frequencies in a liquid chamber. High speed movies of passive tracers in the oscillating 3-D flow fields reveal the spatio-temporal structure of the induced fluid motion. Complementing these experimental studies, we have developed a family of exact solutions of the Stoke's equations for a spheroid sweeping a double cone in free space, and an asymptotic solution for a spinning slender rod sweeping an upright cone above a flat, infinite no-slip plane. We are using these solutions to develop a mathematical package to quantitatively model, and predict the tracer motion induced by the spinning nano-rods with and without Brownian noise. To understand the effect of these epicyclical flows on molecular conformations, we have studied the conformation of fluorescently labeled, single DNA molecules (lambda-DNA) in the flow produced by a precessing nanowire. The flow patterns in a viscoelastic medium about a precessing nanowire are also presented to reveal the epicyclical flows in a more bio-related environment.

  7. The Brief Obsessive-Compulsive Scale (BOCS): a self-report scale for OCD and obsessive-compulsive related disorders. (United States)

    Bejerot, Susanne; Edman, Gunnar; Anckarsäter, Henrik; Berglund, Gunilla; Gillberg, Christopher; Hofvander, Björn; Humble, Mats B; Mörtberg, Ewa; Råstam, Maria; Ståhlberg, Ola; Frisén, Louise


    The Brief Obsessive Compulsive Scale (BOCS), derived from the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) and the children's version (CY-BOCS), is a short self-report tool used to aid in the assessment of obsessive-compulsive symptoms and diagnosis of obsessive-compulsive disorder (OCD). It is widely used throughout child, adolescent and adult psychiatry settings in Sweden but has not been validated up to date. The aim of the current study was to examine the psychometric properties of the BOCS amongst a psychiatric outpatient population. The BOCS consists of a 15-item Symptom Checklist including three items (hoarding, dysmorphophobia and self-harm) related to the DSM-5 category "Obsessive-compulsive related disorders", accompanied by a single six-item Severity Scale for obsessions and compulsions combined. It encompasses the revisions made in the Y-BOCS-II severity scale by including obsessive-compulsive free intervals, extent of avoidance and excluding the resistance item. 402 adult psychiatric outpatients with OCD, attention-deficit/hyperactivity disorder, autism spectrum disorder and other psychiatric disorders completed the BOCS. Principal component factor analysis produced five subscales titled "Symmetry", "Forbidden thoughts", "Contamination", "Magical thoughts" and "Dysmorphic thoughts". The OCD group scored higher than the other diagnostic groups in all subscales (P OCD from other non-OCD related psychiatric disorders. The current study provides strong support for the utility of the BOCS in the assessment of obsessive-compulsive symptoms in clinical psychiatry.

  8. Scaling the relative dominance of exogenous drivers in structuring desert small mammal assemblages (United States)

    Rodríguez, Daniela; Ojeda, Ricardo A.


    Assemblage patterns could be primarily generated by two types of drivers: exogenous (such as environmental and climatic factors) and endogenous (interactions such as competition, predation, mutualism or herbivory). The most widely accepted hypothesis states that at smaller scales (such as patch scale), interspecific interactions are the major drivers structuring communities, whereas at larger regional scales, factors such as climate, topography and soil act as ecological filters that determine assemblage composition. The general aim of this paper is to compare different exogenous drivers in terms of their relative dominance in structuring desert small mammal communities across a range of spatial scales, from patch to regional, and compare them with previous results on endogenous drivers. Our results show that as spatial scale increases, the explanatory power of exogenous factors also increases, e.g. from 17% at the patch scale (i.e. abundance) to 99% at the regional scale (i.e. diversity). Moreover, environmental drivers vary in type and strength depending on the community estimator across several spatial scales. On the other hand, endogenous drivers such as interspecific interactions are more important at the patch scale, diminishing in importance towards the regional scale. Therefore, the relative importance of exogenous versus endogenous drivers affects small mammal assemblage structure at different spatial scales. Our results fill up a knowledge gap concerning ecological drivers of assemblage structure at intermediate spatial scales for Monte desert small mammals, and highlight the importance of dealing with multi-causal factors in explaining ecological patterns of assemblages.

  9. Stress and depression scales in aphasia: relation between the aphasia depression rating scale, stroke aphasia depression questionnaire-10, and the perceived stress scale. (United States)

    Laures-Gore, Jacqueline S; Farina, Matthew; Moore, Elliot; Russell, Scott


    Assessment and diagnosis of post-stroke depression (PSD) among patients with aphasia presents unique challenges. A gold standard assessment of PSD among this population has yet to be identified. The first aim was to investigate the association between two depression scales developed for assessing depressive symptoms among patients with aphasia. The second aim was to evaluate the relation between these scales and a measure of perceived stress. Twenty-five (16 male; 9 female) individuals with history of left hemisphere cerebrovascular accident (CVA) were assessed for depression and perceived stress using the Stroke Aphasic Depression Questionnaire-10 (SADQ-10), the Aphasia Depression Rating Scale (ADRS), and the Perceived Stress Scale (PSS). SADQ-10 and ADRS ratings were strongly correlated with each other (r = 0.708, p perceived stress may also be an important factor in assessment of depressive symptoms.

  10. EI Scale: an environmental impact assessment scale related to the construction materials used in the reinforced concrete

    Directory of Open Access Journals (Sweden)

    Gilson Morales


    Full Text Available This study aimed to create EI Scal, an environmental impact assessment scal, related to construction materials used in the reinforced concrete structure production. The main reason for that was based on the need to classify the environmental impact levels through indicators to assess the damage level process. The scale allowed converting information to estimate the environmental impact caused. Indicators were defined trough the requirements and classification criteria of impact aspects considering the eco-design theory. Moreover, the scale allowed classifying the materials and processes environmental impact through four score categories which resulted in a single final impact score. It was concluded that the EI scale could be cheap, accessible, and relevant tool for environmental impact controlling and reduction, allowing the planning and material specification to minimize the construction negative effects caused in the environment.

  11. Transverse permeability of woven fabrics

    NARCIS (Netherlands)

    Grouve, Wouter Johannes Bernardus; Akkerman, Remko; Loendersloot, Richard; van den Berg, S.


    The transverse permeability is an essential input in describing the consolidation process of CETEX® laminates. A two-dimensional, finite difference based, Stokes flow solver has been developed to determine the mesoscopic permeability of arbitrary fabric structures. The use of a multigrid solver

  12. Permeability, storage and hydraulic diffusivity controlled by earthquakes (United States)

    Brodsky, E. E.; Fulton, P. M.; Xue, L.


    Earthquakes can increase permeability in fractured rocks. In the farfield, such permeability increases are attributed to seismic waves and can last for months after the initial earthquake. Laboratory studies suggest that unclogging of fractures by the transient flow driven by seismic waves is a viable mechanism. These dynamic permeability increases may contribute to permeability enhancement in the seismic clouds accompanying hydraulic fracking. Permeability enhancement by seismic waves could potentially be engineered and the experiments suggest the process will be most effective at a preferred frequency. We have recently observed similar processes inside active fault zones after major earthquakes. A borehole observatory in the fault that generated the M9.0 2011 Tohoku earthquake reveals a sequence of temperature pulses during the secondary aftershock sequence of an M7.3 aftershock. The pulses are attributed to fluid advection by a flow through a zone of transiently increased permeability. Directly after the M7.3 earthquake, the newly damaged fault zone is highly susceptible to further permeability enhancement, but ultimately heals within a month and becomes no longer as sensitive. The observation suggests that the newly damaged fault zone is more prone to fluid pulsing than would be expected based on the long-term permeability structure. Even longer term healing is seen inside the fault zone of the 2008 M7.9 Wenchuan earthquake. The competition between damage and healing (or clogging and unclogging) results in dynamically controlled permeability, storage and hydraulic diffusivity. Recent measurements of in situ fault zone architecture at the 1-10 meter scale suggest that active fault zones often have hydraulic diffusivities near 10-2 m2/s. This uniformity is true even within the damage zone of the San Andreas fault where permeability and storage increases balance each other to achieve this value of diffusivity over a 400 m wide region. We speculate that fault zones

  13. A Scale for Measuring Teachers’ Mathematics-Related Beliefs: A Validity and Reliability Study

    Directory of Open Access Journals (Sweden)

    Yoppy Wahyu Purnomo


    Full Text Available The purpose of this study was to develop and validate a scale of teacher beliefs related to mathematics, namely, beliefs about the nature of mathematics, mathematics teaching, and assessment in mathematics learning. A scale development study was used to achieve it. The draft scale consisted of 54 items in which 16 items related to beliefs about the nature of mathematics, 23 items related to beliefs about the teaching of mathematics, and 15 items related to beliefs about assessment in mathematics learning. At the first phase, 252 primary school teachers participated and exploratory factor analysis (EFA was performed to evaluate the structure of the scale factor. There were two factors at each scale resulted from the analysis. At the second phase, 350 primary school teachers participated and confirmatory factor analysis (CFA was performed to confirm the factors resulted from the EFA. The result of CFA indicated that the established model had sufficient fit indices. In addition, each factor had an adequate internal consistency coefficient, which was in the range of 0.715–0.787. Thus, this scale could be a satisfactory tool to assess teachers' mathematics-related beliefs. Subsequent studies could combine these three scales into an integrated scale, to simplify statistical analysis.

  14. Upscaling verticle permeability within a fluvio-aeolian reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, S.D.; Corbett, P.W.M.; Jensen, J.L. [Heriot-Watt Univ., Edinburgh (United Kingdom)


    Vertical permeability (k{sub v}) is a crucial factor in many reservoir engineering issues. To date there has been little work undertaken to understand the wide variation of k{sub v} values measured at different scales in the reservoir. This paper presents the results of a study in which we have modelled the results of a downhole well tester using a statistical model and high resolution permeability data. The work has demonstrates and quantifies a wide variation in k{sub v} at smaller, near wellbore scales and has implications for k{sub v} modelling at larger scales.

  15. A Reconciliation of Packed Column Permeability Data: Column Permeability as a Function of Particle Porosity

    Directory of Open Access Journals (Sweden)

    Hubert M. Quinn


    Full Text Available In his textbook teaching of packed bed permeability, Georges Guiochon uses mobile phase velocity as the fluid velocity term in his elaboration of the Darcy permeability equation. Although this velocity frame makes a lot of sense from a thermodynamic point of view, it is valid only with respect to permeability at a single theoretical boundary condition. In his more recent writings, however, Guiochon has departed from his long-standing mode of discussing permeability in terms of the Darcy equation and has embraced the well-known Kozeny-Blake equation. In this paper, his teaching pertaining to the constant in the Kozeny-Blake equation is examined and, as a result, a new correlation coefficient is identified and defined herein based on the velocity frame used in his teaching. This coefficient correlates pressure drop and fluid velocity as a function of particle porosity. We show that in their experimental protocols, Guiochon et al. have not adhered to a strict material balance of permeability which creates a mismatch of particle porosity and leads to erroneous conclusions regarding the value of the permeability coefficient in the Kozeny-Blake equation. By correcting the experimental data to properly reflect particle porosity we reconcile the experimental results of Guiochon and Giddings, resulting in a permeability reference chart which is presented here for the first time. This reference chart demonstrates that Guiochon’s experimental data, when properly normalized for particle porosity and other related discrepancies, corroborates the value of 267 for the constant in the Kozeny-Blake equation which was derived by Giddings in 1965.

  16. Validation of the Career-Related Parent Support Scale among Chinese High School Students (United States)

    Cheng, Sandra; Yuen, Mantak


    The Career-Related Parent Support Scale (CRPSS; Turner, Alliman-Brissett, Lapan, Udipi, & Ergun, 2003) was translated and modified to form the 24-item Chinese version of the scale. As in the case of the original CRPSS, the Chinese version includes 4 subscales (Instrumental Assistance, Emotional Support, Verbal Encouragement, and Career-Related…

  17. The impact of different aperture distribution models and critical stress criteria on equivalent permeability in fractured rocks

    DEFF Research Database (Denmark)

    Bisdom, Kevin; Bertotti, Giovanni; Nick, Hamid


    Predicting equivalent permeability in fractured reservoirs requires an understanding of the fracture network geometry and apertures. There are different methods for defining aperture, based on outcrop observations (power law scaling), fundamental mechanics (sublinear length-aperture scaling......-world large-scale fracture networks. (Sub)linear length scaling predicts the largest average aperture and equivalent permeability. Barton-Bandis aperture is smaller, predicting on average a sixfold increase compared to matrix permeability. Application of critical stress criteria results in a decrease...

  18. 2002 Status of the Armed Forces Survey - Workplace and Gender Relations: Report on Scales and Measures

    National Research Council Canada - National Science Library

    Ormerod, Alayne


    ...: Workplace and Gender Relations Survey (2002 WGR). This report describes advances from previous surveys and presents results on scale development as obtained from 19,960 respondents to this survey...

  19. Planck early results. XII. Cluster Sunyaev-Zeldovich optical scaling relations

    DEFF Research Database (Denmark)

    Poutanen, T.; Natoli, P.; Polenta, G.


    We present the Sunyaev-Zeldovich (SZ) signal-to-richness scaling relation (Y500 - N200) for the MaxBCG cluster catalogue. Employing a multi-frequency matched filter on the Planck sky maps, we measure the SZ signal for each cluster by adapting the filter according to weak-lensing calibrated mass...... law over the full richness range. It has a lower normalisation at given N200 than predicted based on X-ray models and published mass-richness relations. An X-ray subsample, however, does conform to the predicted scaling, and model predictions do reproduce the relation between our measured bin...... SZ/optical data set, extending the list of known cluster scaling laws to include SZ-optical properties. The data set offers essential clues for models of galaxy formation. Moreover, the lower normalisation of the SZ-mass relation implied by the observed SZ-richness scaling has important consequences...

  20. Evolution of the K-band Galaxy Cluster Luminosity Function and Scaling Relations


    Lin, Yen-Ting; Mohr, Joseph J.; Gonzalez, Anthony H.; Stanford, S Adam


    We study the evolution of two fundamental properties of galaxy clusters: the luminosity function (LF) and the scaling relations between the total galaxy number N (or luminosity) and cluster mass M. Using a sample of 27 clusters (0

  1. Permeability testing of biomaterial membranes

    Energy Technology Data Exchange (ETDEWEB)

    Dreesmann, L; Hajosch, R; Nuernberger, J Vaz; Schlosshauer, B [NMI Natural and Medical Sciences Institute at University Tuebingen, Markwiesenstr. 55, D-72770 Reutlingen (Germany); Ahlers, M [GELITA AG, Gammelsbacher Str. 2, D-69412 Eberbach (Germany)], E-mail:


    The permeability characteristics of biomaterials are critical parameters for a variety of implants. To analyse the permeability of membranes made from crosslinked ultrathin gelatin membranes and the transmigration of cells across the membranes, we combined three technical approaches: (1) a two-chamber-based permeability assay, (2) cell culturing with cytochemical analysis and (3) biochemical enzyme electrophoresis (zymography). Based on the diffusion of a coloured marker molecule in conjunction with photometric quantification, permeability data for a gelatin membrane were determined in the presence or absence of gelatin degrading fibroblasts. Cytochemical evaluation after cryosectioning of the membranes was used to ascertain whether fibroblasts had infiltrated the membrane inside. Zymography was used to investigate the potential release of proteases from fibroblasts, which are known to degrade collagen derivatives such as gelatin. Our data show that the diffusion equilibrium of a low molecular weight dye across the selected gelatin membrane is approached after about 6-8 h. Fibroblasts increase the permeability due to cavity formation in the membrane inside without penetrating the membrane for an extended time period (>21 days in vitro). Zymography indicates that cavity formation is most likely due to the secretion of matrix metalloproteinases. In summary, the combination of the depicted methods promises to facilitate a more rational development of biomaterials, because it provides a rapid means of determining permeability characteristics and bridges the gap between descriptive methodology and the mechanistic understanding of permeability alterations due to biological degradation.

  2. Criterion-related validity of challenging behaviour scales: a review of evidence in the literature. (United States)

    Turton, Raistrick W


    Behaviour that challenges has negative impacts on physical and emotional well-being and quality of life. Challenging behaviour scales are used to identify needs and evaluate interventions and must be valid measures. Criterion-related validity is important, and the best quality assessment uses direct measures of behaviour as criteria. Previous reviews of scales affirm their validity but present little supporting evidence. The current review examines the evidence presented in studies of validity. Searches of MEDLINE and PsycINFO to identify scales that focus on challenging behaviour and find publications that assess their criterion-related validity. Searches identified twelve scales and 21 publications that assess validity. One assessment used direct measures of behaviour, and the remainder used indirect measures that themselves have limited evidence of validity, including membership of diagnostic or service groups and other scales. Little firm evidence of validity was found, but what was found is encouraging. © 2014 John Wiley & Sons Ltd.

  3. Using artificial intelligence to predict permeability from petrographic data (United States)

    Ali, Maqsood; Chawathé, Adwait


    Petrographic data collected during thin section analysis can be invaluable for understanding the factors that control permeability distribution. Reliable prediction of permeability is important for reservoir characterization. The petrographic elements (mineralogy, porosity types, cements and clays, and pore morphology) interact with each other uniquely to generate a specific permeability distribution. It is difficult to quantify accurately this interaction and its consequent effect on permeability, emphasizing the non-linear nature of the process. To capture these non-linear interactions, neural networks were used to predict permeability from petrographic data. The neural net was used as a multivariate correlative tool because of its ability to learn the non-linear relationships between multiple input and output variables. The study was conducted on the upper Queen formation called the Shattuck Member (Permian age). The Shattuck Member is composed of very fine-grained arkosic sandstone. The core samples were available from the Sulimar Queen and South Lucky Lake fields located in Chaves County, New Mexico. Nineteen petrographic elements were collected for each permeability value using a combined minipermeameter-petrographic technique. In order to reduce noise and overfitting the permeability model, these petrographic elements were screened, and their control (ranking) with respect to permeability was determined using fuzzy logic. Since the fuzzy logic algorithm provides unbiased ranking, it was used to reduce the dimensionality of the input variables. Based on the fuzzy logic ranking, only the most influential petrographic elements were selected as inputs for permeability prediction. The neural net was trained and tested using data from Well 1-16 in the Sulimar Queen field. Relying on the ranking obtained from the fuzzy logic analysis, the net was trained using the most influential three, five, and ten petrographic elements. A fast algorithm (the scaled conjugate

  4. An Experimental Study of Micron-Size Zero-Valent Iron Emplacement in Permeable Porous Media Using Polymer-Enhanced Fluids

    Energy Technology Data Exchange (ETDEWEB)

    Oostrom, Mart; Wietsma, Thomas W.; Covert, Matthew A.; Vermeul, Vince R.


    At the Hanford Site, an extensive In Situ Redox Manipulation (ISRM) permeable reactive barrier was installed to prevent chromate from reaching the Columbia River. However, chromium has been detected in several wells, indicating a premature loss of the reductive capacity in the aquifer. One possible cause for premature chromate breakthrough is associated with the presence of high-permeability zones in the aquifer. In these zones, groundwater moves relatively fast and is able to oxidize iron more rapidly. There is also a possibility that the high-permeability flow paths are deficient in reducing equivalents (e.g. reactive iron), required for barrier performance. One way enhancement of the current barrier reductive capacity can be achieved is by the addition of micron-scale zero-valent iron to the high-permeability zones within the aquifer. The potential emplacement of zero-valent iron (Fe0) into high-permeability Hanford sediments (Ringold Unit E gravels) using shear-thinning fluids containing polymers was investigated in three-dimensional wedge-shaped aquifer models. Polymers were used to create a suspension viscous enough to keep the Fe0 in solution for extended time periods to improve colloid movement into the porous media without causing a permanent detrimental decrease in hydraulic conductivity. Porous media were packed in the wedge-shaped flow cell to create either a heterogeneous layered system with a high-permeability zone in between two low-permeability zones or a high-permeability channel surrounded by low-permeability materials. The injection flow rate, polymer type, polymer concentration, and injected pore volumes were determined based on preliminary short- and long-column experiments.

  5. Hierarchical multi-taxa models inform riparian vs. hydrologic restoration of urban streams in a permeable landscape. (United States)

    Gwinn, Daniel C; Middleton, Jen A; Beesley, Leah; Close, Paul; Quinton, Belinda; Storer, Tim; Davies, Peter M


    The degradation of streams caused by urbanization tends to follow predictable patterns; however, there is a growing appreciation for heterogeneity in stream response to urbanization due to the local geoclimatic context. Furthermore, there is building evidence that streams in mildly sloped, permeable landscapes respond uncharacteristically to urban stress calling for a more nuanced approach to restoration. We evaluated the relative influence of local-scale riparian characteristics and catchment-scale imperviousness on the macroinvertebrate assemblages of streams in the flat, permeable urban landscape of Perth, Western Australia. Using a hierarchical multi-taxa model, we predicted the outcomes of stylized stream restoration strategies to increase the riparian integrity at the local scale or decrease the influences of imperviousness at the catchment scale. In the urban streams of Perth, we show that local-scale riparian restoration can influence the structure of macroinvertebrate assemblages to a greater degree than managing the influences of catchment-scale imperviousness. We also observed an interaction between the effect of riparian integrity and imperviousness such that the effect of increased riparian integrity was enhanced at lower levels of catchment imperviousness. This study represents one of few conducted in flat, permeable landscapes and the first aimed at informing urban stream restoration in Perth, adding to the growing appreciation for heterogeneity of the Urban Stream Syndrome and its importance for urban stream restoration. © 2017 by the Ecological Society of America.

  6. Numerical measurements of scaling relations in two-dimensional conformal fluid turbulence (United States)

    Westernacher-Schneider, John Ryan; Lehner, Luis


    We present measurements of relativistic scaling relations in (2+1)-dimensional conformal fluid turbulence from direct numerical simulations, in the weakly compressible regime. These relations were analytically derived previously in [1] for a relativistic fluid; this work is a continuation of that study, providing further analytical insights together with numerical experiments to test the scaling relations and extract other important features characterizing the turbulent behavior. We first explicitly demonstrate that the non-relativistic limit of these scaling relations reduce to known results from the statistical theory of incompressible Navier-Stokes turbulence. In simulations of the inverse-cascade range, we find the relevant relativistic scaling relation is satisfied to a high degree of ac-curacy. We observe that the non-relativistic versions of this scaling relation underperform the relativistic one in both an absolute and relative sense, with a progressive degradation as the rms Mach number increases from 0.14 to 0.19. In the direct-cascade range, the two relevant relativistic scaling relations are satisfied with a lower degree of accuracy in a simulation with rms Mach number 0.11. We elucidate the poorer agreement with further simulations of an incompressible Navier-Stokes fluid. Finally, as has been observed in the incompressible Navier-Stokes case, we show that the energy spectrum in the inverse-cascade of the conformal fluid exhibits k -2 scaling rather than the Kolmogorov/Kraichnan expectation of k -5/3, and that it is not necessarily associated with compressive effects. We comment on the implications for a recent calculation of the fractal dimension of a turbulent (3 + 1)-dimensional AdS black brane.

  7. Geothermal Permeability Enhancement - Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Joe Beall; Mark Walters


    The overall objective is to apply known permeability enhancement techniques to reduce the number of wells needed and demonstrate the applicability of the techniques to other undeveloped or under-developed fields. The Enhanced Geothermal System (EGS) concept presented in this project enhances energy extraction from reduced permeability zones in the super-heated, vapor-dominated Aidlin Field of the The Geysers geothermal reservoir. Numerous geothermal reservoirs worldwide, over a wide temperature range, contain zones of low permeability which limit the development potential and the efficient recovery of heat from these reservoirs. Low permeability results from poorly connected fractures or the lack of fractures. The Enhanced Geothermal System concept presented here expands these technologies by applying and evaluating them in a systematic, integrated program.

  8. Permeability of soils in Mississippi (United States)

    O'Hara, Charles G.


    The permeability of soils in Mississippi was determined and mapped using a geographic information system (GIS). Soil permeabilities in Mississippi were determined to range in value from nearly 0.0 to values exceeding 5.0 inches per hour. The U.S. Soil Conservation Service's State Soil Geographic Data Base (STATSGO) was used as the primary source of data for the determination of area-weighted soil permeability. STATSGO provides soil layer properties that are spatially referenced to mapped areas. These mapped areas are referred to as polygons in the GIS. The polygons arc boundaries of soils mapped as a group and are given unique Map Unit Identifiers (MUIDs). The data describing the physical characteristics of the soils within each polygon are stored in a tabular data base format and are referred to as attributes. The U.S. Soil Conservation Service developed STATSGO to be primarily used as a guide for regional resource planning, management, and monitoring. STATSGO was designed so that soil information could be extracted from properties tables at the layer level, combined by component, and statistically expanded to cover the entire map unit. The results of this study provide a mapped value for permeability which is representative of the vertical permeability of soils in that area. The resultant permeability map provides a representative vertical soil permeability for a given area sufficient for county, multi- county, and area planning, and will be used as the soil permeability data component in the evaluation of the susceptibility of major aquifers to contami- nation in Mississippi.

  9. Permeability theory and Palace Athena. (United States)

    Stamps, Arthur E


    Permeability theory suggests that safety in environments depends on how far and how easily one can perceive or move through environments. Parts of environments that limit perception or retard locomotion elicit impressions of being enclosed, so properties of environments that influence perceived enclosure are important in permeability theory. One prediction of permeability theory is that the more permeable the boundary, the less enclosed the region within that boundary will seem to be. Another prediction is that boundary depth will have little influence on perceived enclosure. These predictions were tested in the venue of Greek temples. 30 participants were tested (14 men, 16 women; M age = 40 yr.), who rated perceived enclosure for 18 stimuli. The stimuli were constructed using a virtual scene from the Tholos in Delphi with the positions of the columns forming the boundaries. The boundaries were designed to have different levels of permeability and depth. Data were analyzed in terms of effect sizes and focused comparisons. Results indicated that perceived enclosure was most strongly influenced by the visual permeability of the boundary, while depth of boundary had a much smaller effect on perceived enclosure.

  10. Psychometric Evaluation of Data from the Race-Related Events Scale (United States)

    Crusto, Cindy A.; Dantzler, John; Roberts, Yvonne Humenay; Hooper, Lisa M.


    Using exploratory factor analysis, we examined the factor structure of data collected from the Race-Related Events Scale, which assesses perceived exposure to race-related stress. Our sample (N = 201) consisted of diverse caregivers of Head Start preschoolers. Three factors explained 81% of the variance in the data and showed sound reliability.

  11. Peak precipitation intensity in relation to atmospheric conditions and large-scale forcing at midlatitudes

    NARCIS (Netherlands)

    Loriaux, J.M.; Lenderink, Geert; Siebesma, A.P.


    Research on relations between atmospheric conditions and extreme precipitation is important to understand and model present-day climate extremes and assess how precipitation extremes might evolve in a future climate. Here we present a statistical analysis of the relation between large-scale

  12. Eysenck Personality Questionnaire scales and paper-and-pencil tests related to creativity. (United States)

    Schuldberg, David


    Pearson correlations for scores on scales of the 1975 version of the Eysenck Personality Questionnaire with measures of schizotypy, hypomania, and creative traits are reported for 625 undergraduates. The Psychoticism scores are correlated .30 with Hypomanic traits, .25 with Perceptual Aberration, and .20 with the How Do You Think, a test of attitudes and activities related to creativity. Extraversion is also related to creativity-relevant scores. Results support a broad and nonspecific role for the Psychoticism scale in relation to both creativity and subclinical symptomatology.

  13. A low Fermi scale from a simple gaugino-scalar mass relation

    Energy Technology Data Exchange (ETDEWEB)

    Bruemmer, F. [International School for Advanced Studies, Trieste (Italy); Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Buchmueller, W. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)


    In supersymmetric extensions of the Standard Model, the Fermi scale of electroweak symmetry breaking is determined by the pattern of supersymmetry breaking. We present an example, motivated by a higher-dimensional GUT model, where a particular mass relation between the gauginos, third-generation squarks and Higgs fields of the MSSM leads to a Fermi scale smaller than the soft mass scale. This is in agreement with the measured Higgs boson mass. The {mu} parameter is generated independently of supersymmetry breaking, however the {mu} problem becomes less acute due to the little hierarchy between the soft mass scale and the Fermi scale as we argue. The resulting superparticle mass spectra depend on the localization of quark and lepton fields in higher dimensions. In one case, the squarks of the first two generations as well as the gauginos and higgsinos can be in the range of the LHC. Alternatively, only the higgsinos may be accessible at colliders. The lightest superparticle is the gravitino.

  14. Working memory performance inversely predicts spontaneous delta and theta-band scaling relations. (United States)

    Euler, Matthew J; Wiltshire, Travis J; Niermeyer, Madison A; Butner, Jonathan E


    Electrophysiological studies have strongly implicated theta-band activity in human working memory processes. Concurrently, work on spontaneous, non-task-related oscillations has revealed the presence of long-range temporal correlations (LRTCs) within sub-bands of the ongoing EEG, and has begun to demonstrate their functional significance. However, few studies have yet assessed the relation of LRTCs (also called scaling relations) to individual differences in cognitive abilities. The present study addressed the intersection of these two literatures by investigating the relation of narrow-band EEG scaling relations to individual differences in working memory ability, with a particular focus on the theta band. Fifty-four healthy adults completed standardized assessments of working memory and separate recordings of their spontaneous, non-task-related EEG. Scaling relations were quantified in each of the five classical EEG frequency bands via the estimation of the Hurst exponent obtained from detrended fluctuation analysis. A multilevel modeling framework was used to characterize the relation of working memory performance to scaling relations as a function of general scalp location in Cartesian space. Overall, results indicated an inverse relationship between both delta and theta scaling relations and working memory ability, which was most prominent at posterior sensors, and was independent of either spatial or individual variability in band-specific power. These findings add to the growing literature demonstrating the relevance of neural LRTCs for understanding brain functioning, and support a construct- and state-dependent view of their functional implications. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Interspecific scaling patterns of talar articular surfaces within primates and their closest living relatives. (United States)

    Yapuncich, Gabriel S; Boyer, Doug M


    The articular facets of interosseous joints must transmit forces while maintaining relatively low stresses. To prevent overloading, joints that transmit higher forces should therefore have larger facet areas. The relative contributions of body mass and muscle-induced forces to joint stress are unclear, but generate opposing hypotheses. If mass-induced forces dominate, facet area should scale with positive allometry to body mass. Alternatively, muscle-induced forces should cause facets to scale isometrically with body mass. Within primates, both scaling patterns have been reported for articular surfaces of the femoral and humeral heads, but more distal elements are less well studied. Additionally, examination of complex articular surfaces has largely been limited to linear measurements, so that 'true area' remains poorly assessed. To re-assess these scaling relationships, we examine the relationship between body size and articular surface areas of the talus. Area measurements were taken from microCT scan-generated surfaces of all talar facets from a comprehensive sample of extant euarchontan taxa (primates, treeshrews, and colugos). Log-transformed data were regressed on literature-derived log-body mass using reduced major axis and phylogenetic least squares regressions. We examine the scaling patterns of muscle mass and physiological cross-sectional area (PCSA) to body mass, as these relationships may complicate each model. Finally, we examine the scaling pattern of hindlimb muscle PCSA to talar articular surface area, a direct test of the effect of mass-induced forces on joint surfaces. Among most groups, there is an overall trend toward positive allometry for articular surfaces. The ectal (= posterior calcaneal) facet scales with positive allometry among all groups except 'sundatherians', strepsirrhines, galagids, and lorisids. The medial tibial facet scales isometrically among all groups except lemuroids. Scaling coefficients are not correlated with sample size

  16. Interspecific scaling patterns of talar articular surfaces within primates and their closest living relatives (United States)

    Yapuncich, Gabriel S; Boyer, Doug M


    The articular facets of interosseous joints must transmit forces while maintaining relatively low stresses. To prevent overloading, joints that transmit higher forces should therefore have larger facet areas. The relative contributions of body mass and muscle-induced forces to joint stress are unclear, but generate opposing hypotheses. If mass-induced forces dominate, facet area should scale with positive allometry to body mass. Alternatively, muscle-induced forces should cause facets to scale isometrically with body mass. Within primates, both scaling patterns have been reported for articular surfaces of the femoral and humeral heads, but more distal elements are less well studied. Additionally, examination of complex articular surfaces has largely been limited to linear measurements, so that ‘true area' remains poorly assessed. To re-assess these scaling relationships, we examine the relationship between body size and articular surface areas of the talus. Area measurements were taken from microCT scan-generated surfaces of all talar facets from a comprehensive sample of extant euarchontan taxa (primates, treeshrews, and colugos). Log-transformed data were regressed on literature-derived log-body mass using reduced major axis and phylogenetic least squares regressions. We examine the scaling patterns of muscle mass and physiological cross-sectional area (PCSA) to body mass, as these relationships may complicate each model. Finally, we examine the scaling pattern of hindlimb muscle PCSA to talar articular surface area, a direct test of the effect of mass-induced forces on joint surfaces. Among most groups, there is an overall trend toward positive allometry for articular surfaces. The ectal (= posterior calcaneal) facet scales with positive allometry among all groups except ‘sundatherians', strepsirrhines, galagids, and lorisids. The medial tibial facet scales isometrically among all groups except lemuroids. Scaling coefficients are not correlated with sample

  17. Validity and reliability of the tuberculosis-related stigma scale version for Brazilian Portuguese. (United States)

    de Almeida Crispim, Juliane; da Silva, Laís Mara Caetano; Yamamura, Mellina; Popolin, Marcela Paschoal; Ramos, Antônio Carlos Vieira; Arroyo, Luiz Henrique; de Queiroz, Ana Angélica Rêgo; de Souza Belchior, Aylana; Dos Santos, Danielle Talita; Pieri, Flávia Meneguetti; Rodrigues, Ludmila Barbosa Bandeira; Protti, Simone Terezinha; Pinto, Ione Carvalho; Palha, Pedro Fredemir; Arcêncio, Ricardo Alexandre


    Stigma associated with tuberculosis (TB) has been an object of interest in several regions of the world. The behaviour presented by patients as a result of social discrimination has contributed to delays in diagnosis and the abandonment of treatment, leading to an increase in the cases of TB and drug resistance. The identification of populations affected by stigma and its measurement can be assessed with the use of valid and reliable instruments developed or adapted to the target culture. This aim of this study was to analyse the initial psychometric properties of the Tuberculosis-Related Stigma scale in Brazil, for TB patients. The Tuberculosis-Related Stigma scale is a specific scale for measuring stigma associated with TB, originally validated in Thailand. It presents two dimensions to be assessed, namely Community perspectives toward tuberculosis and Patient perspectives toward tuberculosis. The first has 11 items regarding the behaviour of the community in relation to TB, and the second is made up of 12 items related to feelings such as fear, guilt and sorrow in coping with the disease. A pilot test was conducted with 83 TB patients, in order to obtain the initial psychometric properties of the scale in the Brazilian Portuguese version, enabling simulation of the field study. As regards its psychometric properties, the scale presented acceptable internal consistency for its dimensions, with values ≥0.70, the absence of floor and ceiling effects, which is favourable for the property of scale responsiveness, satisfactory converging validity for both dimensions, with values over 0.30 for initial studies, and diverging validity, with adjustment values different from 100%. The results found show that the Tuberculosis-Related Stigma scale can be a valid and reliable instrument for the Brazilian context.

  18. Modeling the Relationship Between Porosity and Permeability During Oxidation of Ablative Materials (United States)

    Thornton, John M.; Panerai, Francesco; Ferguson, Joseph C.; Borner, Arnaud; Mansour, Nagi N.


    The ablative materials used in thermal protection systems (TPS) undergo oxidation during atmospheric entry which leads to an in-depth change in both permeability and porosity. These properties have a significant affect on heat transfer in a TPS during entry. X-ray micro-tomography has provided 3D images capturing the micro-structure of TPS materials. In this study, we use micro-tomography based simulations to create high-fidelity models relating permeability to porosity during oxidation of FiberForm, the carbon fiber preform of the Phenolic Impregnated Carbon Ablator (PICA) often used as a TPS material. The goal of this study is to inform full-scale models and reduce uncertainty in TPS modeling.

  19. Psychometric evaluation of revised Task-Related Worry Scale (TRWS-R: A Mokken model analysis

    Directory of Open Access Journals (Sweden)

    Martin Marko


    Full Text Available Task-related worries can be understood as an inherent component of an anxious state and stress response. Under evaluating conditions (e.g. cognitive testing, these worries, due to cognitive interference they create, may have undesirable effects on a cognitive performance at hand. Since cognitive interference has been documented to affect a broad spectrum of cognitive performance (Hembree, 1988, development of a method for its assessment is required. For this purpose we modified a part of the original Cognitive Interference Questionnaire (Sarason et al., 1986 in order to create the revised Task- Related Worry Scale (TRWS-R and investigated its psychometric properties. Data from two hundreds of participants (72 male, 139 female; age ranging from 18 to 24 were obtained to inspect the modified scale’s properties on Slovak sample. After the scale was reformulated and shortened, the resulting set of eight items was subjected for examination of internal consistency (Cronbach'salpha, Revelle’sbeta, Armor'stheta, and McDonald'somega coefficients, expected unidimensionality (confirmatory factor analysis, and scalability (nonparametric item response model - Mokken scale analysis. The results indicate that the scale has rather reasonable consistency. Both mean inter-item correlation and corrected mean item-score correlation were relatively high (r= .469 and r = .636 respectively. Additionally, all estimated consistency coefficients reached required thresholds (namely: ? = .88,ß = .79,? = .86,? =.88. Robust confirmatory factor analysis and Cronbach-Mesbah curve convergently supported the hypothesized unidimensional factor solution (CFA fit indexes: ?2 (28= 26.73, p = .143, CFI = .994, TLI = .992, RMSEA = .041, SRMR = .055.. Moreover, Mokken scale analysis indicated that the scale is scalable (scale’s H = .496 and satisfies the criteria of both monotone homogenity model and double monotonicity model (no significant violations were present. Consistency

  20. Differential water permeability and regulation of three aquaporin 4 isoforms

    DEFF Research Database (Denmark)

    Fenton, Robert A; Moeller, Hanne B; Zelenina, Marina


    Aquaporin 4 (AQP4) is expressed in the perivascular glial endfeet and is an important pathway for water during formation and resolution of brain edema. In this study, we examined the functional properties and relative unit water permeability of three functional isoforms of AQP4 expressed...... in the brain (M1, M23, Mz). The M23 isoform gave rise to square arrays when expressed in Xenopus laevis oocytes. The relative unit water permeability differed significantly between the isoforms in the order of M1 > Mz > M23. None of the three isoforms were permeable to small osmolytes nor were they affected...... by changes in external K(+) concentration. Upon protein kinase C (PKC) activation, oocytes expressing the three isoforms demonstrated rapid reduction of water permeability, which correlated with AQP4 internalization. The M23 isoform was more sensitive to PKC regulation than the longer isoforms...

  1. Characterization and estimation of permeability correlation structure from performance data

    Energy Technology Data Exchange (ETDEWEB)

    Ershaghi, I.; Al-Qahtani, M. [Univ. of Southern California, Los Angeles, CA (United States)


    In this study, the influence of permeability structure and correlation length on the system effective permeability and recovery factors of 2-D cross-sectional reservoir models, under waterflood, is investigated. Reservoirs with identical statistical representation of permeability attributes are shown to exhibit different system effective permeability and production characteristics which can be expressed by a mean and variance. The mean and variance are shown to be significantly influenced by the correlation length. Detailed quantification of the influence of horizontal and vertical correlation lengths for different permeability distributions is presented. The effect of capillary pressure, P{sub c1} on the production characteristics and saturation profiles at different correlation lengths is also investigated. It is observed that neglecting P{sub c} causes considerable error at large horizontal and short vertical correlation lengths. The effect of using constant as opposed to variable relative permeability attributes is also investigated at different correlation lengths. Next we studied the influence of correlation anisotropy in 2-D reservoir models. For a reservoir under five-spot waterflood pattern, it is shown that the ratios of breakthrough times and recovery factors of the wells in each direction of correlation are greatly influenced by the degree of anisotropy. In fully developed fields, performance data can aid in the recognition of reservoir anisotropy. Finally, a procedure for estimating the spatial correlation length from performance data is presented. Both the production performance data and the system`s effective permeability are required in estimating the correlation length.

  2. Permeability of WIPP Salt During Damage Evolution and Healing

    Energy Technology Data Exchange (ETDEWEB)



    The presence of damage in the form of microcracks can increase the permeability of salt. In this paper, an analytical formulation of the permeability of damaged rock salt is presented for both initially intact and porous conditions. The analysis shows that permeability is related to the connected (i.e., gas accessible) volumetric strain and porosity according to two different power-laws, which may be summed to give the overall behavior of a porous salt with damage. This relationship was incorporated into a constitutive model, known as the Multimechanism Deformation Coupled Fracture (MDCF) model, which has been formulated to describe the inelastic flow behavior of rock salt due to coupled creep, damage, and healing. The extended model was used to calculate the permeability of rock salt from the Waste Isolation Pilot Plant (WIPP) site under conditions where damage evolved with stress over a time period. Permeability changes resulting from both damage development under deviatoric stresses and damage healing under hydrostatic pressures were considered. The calculated results were compared against experimental data from the literature, which indicated that permeability in damaged intact WIPP salt depends on the magnitude of the gas accessible volumetric strain and not on the total volumetric strain. Consequently, the permeability of WIPP salt is significantly affected by the kinetics of crack closure, but shows little dependence on the kinetics of crack removal by sintering.

  3. Psychological effects of relational job characteristics: validation of the scale for hospital nurses. (United States)

    Santos, Alda; Castanheira, Filipa; Chambel, Maria José; Amarante, Michael Vieira; Costa, Carlos


    This study validates the Portuguese version of the psychological effects of the relational job characteristics scale among hospital nurses in Portugal and Brazil. Increasing attention has been given to the social dimension of work, following the transition to a service economy. Nevertheless, and despite the unquestionable relational characteristics of nursing work, scarce research has been developed among nurses under a relational job design framework. Moreover, it is important to develop instruments that study the effects of relational job characteristics among nurses. We followed Messick's framework for scale validation, comprising the steps regarding the response process and internal structure, as well as relationships with other variables (work engagement and burnout). Statistical analysis included exploratory factor analysis and confirmatory factor analysis. The psychological effects of the relational job characteristics scale provided evidence of good psychometric properties with Portuguese and Brazilian hospital nurses. Also, the psychological effects of the relational job characteristics are associated with nurses' work-related well-being: positively with work engagement and negatively concerning burnout. Hospitals that foster the relational characteristics of nursing work are contributing to their nurses' work-related well-being, which may be reflected in the quality of care and patient safety. © 2017 John Wiley & Sons Ltd.

  4. Determining relative bulk viscosity of kilometre-scale crustal units using field observations and numerical modelling (United States)

    Gardner, Robyn L.; Piazolo, Sandra; Daczko, Nathan R.


    Though the rheology of kilometre-scale polymineralic rock units is crucial for reliable large-scale, geotectonic models, this information is difficult to obtain. In geotectonic models, a layer is defined as an entity at the kilometre scale, even though it is heterogeneous at the millimetre to metre scale. Here, we use the shape characteristics of the boundaries between rock units to derive the relative bulk viscosity of those units at the kilometre scale. We examine the shape of a vertically oriented ultramafic, harzburgitic-lherzolitic unit, which developed a kilometre-scale pinch and swell structure at mid-crustal conditions ( 600 °C, 8.5 kbar), in the Anita Shear Zone, New Zealand. The ultramafic layer is embedded between a typical polymineralic paragneiss to the west, and a feldspar-quartz-hornblende orthogneiss, to the east. Notably, the boundaries on either side of the ultramafic layer give the ultramafics an asymmetric shape. Microstructural analysis shows that deformation was dominated by dislocation creep (n = 3). Based on the inferred rheological behaviour from the field, a series of numerical simulations are performed. Relative and absolute values are derived for bulk viscosity of the rock units by comparing boundary tortuosity difference measured on the field example and the numerical series. Our analysis shows that during deformation at mid-crustal conditions, paragneisses can be 30 times less viscous than an ultramafic unit, whereas orthogneisses have intermediate viscosity, 3 times greater than the paragneisses. If we assume a strain rate of 10- 14 s- 1 the ultramafic, orthogneiss and paragneiss have syn-deformational viscosities of 3 × 1022, 2.3 × 1021 and 9.4 × 1020 Pa s, respectively. Our study shows pinch and swell structures are useful as a gauge to assess relative bulk viscosity of rock units based on shape characteristics at the kilometre scale and in non-Newtonian flow regimes, even where heterogeneity occurs within the units at the

  5. Bentonite Permeability at Elevated Temperature

    Directory of Open Access Journals (Sweden)

    Katherine A. Daniels


    Full Text Available Repository designs frequently favour geological disposal of radioactive waste with a backfill material occupying void space around the waste. The backfill material must tolerate the high temperatures produced by decaying radioactive waste to prevent its failure or degradation, leading to increased hydraulic conductivity and reduced sealing performance. The results of four experiments investigating the effect of temperature on the permeability of a bentonite backfill are presented. Bentonite is a clay commonly proposed as the backfill in repository designs because of its high swelling capacity and very low permeability. The experiments were conducted in two sets of purpose-built, temperature controlled apparatus, designed to simulate isotropic pressure and constant volume conditions within the testing range of 4–6 MPa average effective stress. The response of bentonite during thermal loading at temperatures up to 200 °C was investigated, extending the previously considered temperature range. The results provide details of bentonite’s intrinsic permeability, total stress, swelling pressure and porewater pressure during thermal cycles. We find that bentonite’s hydraulic properties are sensitive to thermal loading and the type of imposed boundary condition. However, the permeability change is not large and can mostly be accounted for by water viscosity changes. Thus, under 150 °C, temperature has a minimal impact on bentonite’s hydraulic permeability.

  6. Influence of high-permeability discs in an axisymmetric model of the Cadarache dynamo experiment (United States)

    Giesecke, A.; Nore, C.; Stefani, F.; Gerbeth, G.; Léorat, J.; Herreman, W.; Luddens, F.; Guermond, J.-L.


    Numerical simulations of the kinematic induction equation are performed on a model configuration of the Cadarache von-Kármán-sodium dynamo experiment. The effect of a localized axisymmetric distribution of relative permeability μr that represents soft iron material within the conducting fluid flow is investigated. The critical magnetic Reynolds number Rmc for dynamo action of the first non-axisymmetric mode roughly scales like Rmcμr - Rmc∞∝μ-1/2r, i.e. the threshold decreases as μr increases. This scaling law suggests a skin effect mechanism in the soft iron discs. More important with regard to the Cadarache dynamo experiment, we observe a purely toroidal axisymmetric mode localized in the high-permeability discs which becomes dominant for large μr. In this limit, the toroidal mode is close to the onset of dynamo action with a (negative) growth rate that is rather independent of the magnetic Reynolds number. We qualitatively explain this effect by paramagnetic pumping at the fluid/disc interface and propose a simplified model that quantitatively reproduces numerical results. The crucial role of the high-permeability discs in the mode selection in the Cadarache dynamo experiment cannot be inferred from computations using idealized pseudo-vacuum boundary conditions (H × n = 0).

  7. Identifying food-related life style segments by a cross-culturally valid scaling device

    DEFF Research Database (Denmark)

    Brunsø, Karen; Grunert, Klaus G.


    We present a new view of life style, based on a cognitive perspective, which makes life style specific to certain areas of consumption. The specific area of consumption studied here is food, resulting in a concept of food-related life style. An instrument is developed that can measure food......-related life style in a cross-culturally valid way. To this end, we have col-lected a pool of 202 items, collected data in three countries, and have con-structed scales based on cross-culturally stable patterns. These scales have then been subjected to a number of tests of reliability and vali-dity. We have...

  8. Relationship Between Composition, Structure and Permeability of Drilling Filter Cakes Relations entre la composition, la structure et la perméabilité des cakes de forage

    Directory of Open Access Journals (Sweden)

    Durand C.


    Full Text Available During drilling operations there is a need to build mud cakes as impervious as possible on the wall of the borehole to prevent damage by fluid loss. To establish the relationship between the filtration properties of mud filter cakes and their structure, drilling fluids containing montmorillonite clay, flexible (Drispac or rigid (xanthan anionic polymers, electrolytes and barite were investigated. Standard API filtration and polymer adsorption measurements were performed. The cake structure was vizualized by cryoscanning electron microscopy. Our study establishes the mechanism of filtration reduction properties of drilling filter cakes. Filtration measurements and cryomicroscopy show that a well dispersed suspension forms a well connected, homogeneous network that prevents fluid loss. Addition of salts to the drilling fluid promotes the aggregation of the clay particles and introduces heterogeneities so that the fluid loss is increased. Addition of anionic polymers causes a better dispersion of the clay particles in the suspension which lowers the filtration rate. In the presence of both salts and polymers, there is a competition effect between the salt-induced aggregation of the clay particles and the dispersion due to polymers, largely governed by the concentration and valence of the electrolytes and the flexibility of the polymers. During the filtration process more filtration reduction properties are obtained by non adsorbed polymers which clog the pores of the cake network and further reduce the filtration rate. The different behavior of the flexible (Drispac and the rigid polymer (xanthan, can be used to optimize their applications in drilling fluids depending on field conditions (temperature, salt conditions. Afin d'éviter l'endommagement des puits par une perte de fluides, il est nécessaire de former, au cours du forage, un cakeaussi imperméable que possible sur la paroi des puits. L'objectif de l'étude est d'établir des relations

  9. Vortical Motions of Baryonic Gas in the Cosmic Web: Growth History and Scaling Relation (United States)

    Zhu, Weishan; Feng, Long-long


    The vortical motions of the baryonic gas residing in large-scale structures are investigated by cosmological hydrodynamic simulations. Proceeding in the formation of the cosmic web, the vortical motions of baryonic matter are pumped up by baroclinity in two stages, i.e., the formation of sheets and filaments. The mean curl velocities are about filaments, and knots at z = 0, respectively. The scaling of the vortical velocity of gas can be well described by the She-Leveque hierarchical turbulence model in the range of l filaments, Df ˜ 1.9-2.2, and smaller than the fractal dimension of sheets, Ds ˜ 2.4-2.7. The vortical kinetic energy of baryonic gas is mainly transported by filaments. Both scalings of mass distribution and vortical velocity increments show distinctive transitions at the turning scale of ˜0.65(1.50) h-1 Mpc, which may be closely related to the characteristic radius of density filaments.

  10. Cross-cultural adaptation and validation to Brazil of the Obesity-related Problems Scale. (United States)

    Brasil, Andreia Mara Brolezzi; Brasil, Fábio; Maurício, Angélica Aparecida; Vilela, Regina Maria


    To validate a reliable version of the Obesity-related Problems Scale in Portuguese to use it in Brazil. The Obesity-related Problems Scale was translated and transculturally adapted. Later it was simultaneously self-applied with a 12-item version of the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0), to 50 obese patients and 50 non-obese individuals, and applied again to half of them after 14 days. The Obesity-related Problems scale was able to differentiate obese from non-obese individuals with higher accuracy than WHODAS 2.0, correlating with this scale and with body mass index. The factor analysis determined a two-dimensional structure, which was confirmed with χ2/df=1.81, SRMR=0.05, and CFI=0.97. The general a coefficient was 0.90 and the inter-item intra-class correlation, in the reapplication, ranged from 0.75 to 0.87. The scale proved to be valid and reliable for use in the Brazilian population, without the need to exclude items.

  11. How fault zones impact regional permeability and groundwater systems: insights from global database of fault zone studies. (United States)

    Scibek, J.; McKenzie, J. M.; Gleeson, T.


    Regional and continental scale groundwater flow models derive aquifer permeability distributions from datasets based on hydraulic tests and calibrated local and regional flow models, however, much of this data does not account for barrier/conduit effects of fault zones, local and regional geothermal flow cells, and other fault-controlled flow systems. In this study we researched and compiled fault zone permeability and conceptual permeability models in different geologic settings from published multidisciplinary literature (structural- and hydro-geology, engineering geology of tunnels and mines, and geothermal projects among others). The geospatial database focuses on data-rich regions such as North America, Europe, and Japan. Regionalization of the dominant conceptual models of fault zones was regionalized based on geological attributes and tested conceptually with simple numerical models, to help incorporate the effect of fault zones on regional to continental flow models. Results show that for large regional and continental scale flow modeling, the fault zone data can be generalized by geology to determine the relative importance of fault conduits vs fault barriers, which can be converted to effective anisotropy ratios for large scale flow, although local fault-controlled flow cells in rift zones require appropriate upscaling. The barrier/conduit properties of fault zones are present in all regions and rock types, and the barrier effect must be properly conceptualized in large scale flow models. The fault zone data from different geologic disciplines have different biases (e.g. outcrop studies, deep drillhole tests, tunnels, etc.) depending on scale of hydraulic tests. Finally, the calibrated recharge estimates for fault controlled flow systems may be lower than for unfaulted flow systems due to predominant barrier (regional anisotropy or permeability reduction), suggesting a "scaling effect" on recharge estimates.

  12. Development and validation of the alcohol-related God locus of control scale. (United States)

    Murray, Thomas S; Goggin, Kathy; Malcarne, Vanessa L


    Control beliefs and spirituality appear to be important factors in recovery from alcoholism. However, the integration of these two constructs has received little attention, and the relationship of spiritually related control beliefs to recovery remains unclear. Currently no measures exist to specifically assess these beliefs. To address this need, the Alcohol-Related God Locus of Control scale (AGLOC) was developed. This 12-item self-report measure assesses perceptions of God/Higher Power's role in recovery from alcoholism. The AGLOC was administered to 144 recovering alcoholics attending Alcoholics Anonymous meetings. Exploratory factor analysis yielded a two-factor solution with one factor related to attributions of God control over initial cessation of drinking (Cessation) and the other factor related to attributions of God control over one's continued maintenance of sobriety (Maintenance). Both subscales and the overall scale demonstrated adequate to high internal consistency. Demonstrating convergent and discriminant validity, the total AGLOC scale and the Cessation subscale were significantly but moderately correlated with spirituality (both frequency and importance), and independent of perceptions of internal control over drinking. Maintenance subscale scores were inversely associated with internal drinking-related scores and were not associated with spiritual importance or frequency of spiritual practice. Findings support the utility of this instrument for the assessment of alcohol-related God/Higher Power locus of control beliefs in an alcoholic population and suggest the importance of further research on changes in alcohol-related God control beliefs throughout the course of recovery.

  13. Large scale inference in the Infinite Relational Model: Gibbs sampling is not enough

    DEFF Research Database (Denmark)

    Albers, Kristoffer Jon; Moth, Andreas Leon Aagard; Mørup, Morten


    The stochastic block-model and its non-parametric extension, the Infinite Relational Model (IRM), have become key tools for discovering group-structure in complex networks. Identifying these groups is a combinatorial inference problem which is usually solved by Gibbs sampling. However, whether...... Gibbs sampling suffices and can be scaled to the modeling of large scale real world complex networks has not been examined sufficiently. In this paper we evaluate the performance and mixing ability of Gibbs sampling in the Infinite Relational Model (IRM) by implementing a high performance Gibbs sampler....... We find that Gibbs sampling can be computationally scaled to handle millions of nodes and billions of links. Investigating the behavior of the Gibbs sampler for different sizes of networks we find that the mixing ability decreases drastically with the network size, clearly indicating a need...

  14. Cosmological dark turbulence and scaling relations in self-gravitating systems (United States)

    Nakamichi, A.; Morikawa, M.

    Many scaling relations have been observed for self-gravitating systems (SGS) in the universe. We explore a consistent understanding of them from a simple principle based on the proposal that the collision-less dark matter (DM) fluid terns into a turbulent state, i.e. dark turbulence, after crossing the caustic surface in the non-linear stage. After deriving Kolmogorov scaling laws from Navier-Stokes and Jeans equations by the method used in solving the Smoluchowski coagulation equation, we apply this to several observations such as the scale-dependent velocity dispersion, mass-luminosity ratio, and mass-angular momentum relation. They all point the concordant value for the constant energy flow per mass: 0.3 cm2/s3, which may be understood as the speed of the hierarchical coalescence process in the cosmic structure formation.

  15. Enhancement of scale-related sensitivity through field-work prototyping and materializations

    Directory of Open Access Journals (Sweden)

    Tadeja Zupančič


    Full Text Available This article addresses the problems related to the student lacking of the comprehension of the space and proportions scale in architectural and urban design education. The research is based on carefully selected case studies taken from our recent architectural-urban design workshops, which have presented a methodological framework process within the design ideas have been tested by the complex process of physical materialization. Our goal have been to develop the adequate methodological model which would enhance the scale-related sensitivity of students through field-work prototyping and materialization »in one to one scale«. The discussion covers some potentials and limitations of the model proposed and focuses to the potentials of the scientific research level in the implementation of the practice-based research in architecture and urban design.

  16. Rigid gas permeable lenses and patient management. (United States)

    Terry, R; Schnider, C; Holden, B A


    The introduction of new rigid gas permeable (RGP) contact lens materials provides the practitioner with a number of alternatives for patient management. But whatever the lens materials used, problems related to the lenses, care and maintenance solutions, and patients may arise. This paper examines concerns such as parameter instability, durability of lenses, compatibility of materials and solutions, patient education and compliance, 3 and 9 o'clock staining, corneal distortion, and lid changes. Suggestions are made on ways to avoid or minimize problems related to RGP lens wear.

  17. Scaling of geometric phase and fidelity susceptibility across the critical points and their relations (United States)

    Cheng, Jia-Ming; Gong, Ming; Guo, Guang-Can; Zhou, Zheng-Wei


    It has been found via numerical simulations that the geometric phase (GP) and fidelity susceptibility (FS) across the quantum critical points exhibit some universal scaling laws. Here we propose a singular function expansion method to find their exact singular forms and the related coefficients across the critical points. For models where the gaps are closed and reopened at special points (k0=0 ,π ), scaling laws can be found as a function of the system length N and parameter deviation λ -λc , where λc refers to one of the critical parameters. Although the GP and FS are defined in totally different ways, we find that these two measurements are essentially determined by the same physics, and as a consequence, their coefficients are closely related. Some of these exact relations are found in the anisotropic XY model and extended Ising models. We also show that the constant term in FS may be accompanied by a discontinuous jump across the critical points and, thus, does not have a universal scaling form. These findings should be in contrast to the cases where the gaps are not closed and reopened at the special points, in which some of the above scaling laws may break down as a function of the system length. Finally, we investigate the second-order derivative of GP, which may also exhibit some scaling laws across the critical point. These exact results can greatly enrich our understanding of GP and FS in the characterization of quantum phase transitions and may even find important applications in related physical quantities, such as entanglement, discord, correlation, and quantum Euler numbers, which may also exhibit scaling laws across the critical points.

  18. Amorphous azithromycin with improved aqueous solubility and intestinal membrane permeability. (United States)

    Aucamp, Marique; Odendaal, Roelf; Liebenberg, Wilna; Hamman, Josias


    Azithromycin (AZM) is a poorly soluble macrolide antibacterial agent. Its low solubility is considered as the major contributing factor to its relatively low oral bioavailability. The aim of this study was to improve the solubility of this active pharmaceutical ingredient (API) by preparing an amorphous form by quench cooling of the melt and to study the influence of the improved solubility on membrane permeability. The amorphous azithromycin (AZM-A) exhibited a significant increase in water solubility when compared to the crystalline azithromycin dihydrate (AZM-DH). The influence that the improved solubility could have on membrane permeability was also studied. The apparent permeability coefficient (Papp) values of AZM-A were statistically significantly higher (p solubility of AZM in the amorphous form also produced improved permeability across excised intestinal tissue at physiological pH values found in the small intestine.

  19. German National Proficiency Scales in Biology: Internal Structure, Relations to General Cognitive Abilities and Verbal Skills (United States)

    Kampa, Nele; Köller, Olaf


    National and international large-scale assessments (LSA) have a major impact on educational systems, which raises fundamental questions about the validity of the measures regarding their internal structure and their relations to relevant covariates. Given its importance, research on the validity of instruments specifically developed for LSA is…

  20. Longitudinal multigroup invariance analysis of the satisfaction with food-related life scale in university students

    DEFF Research Database (Denmark)

    Schnettler, Berta; Miranda, Horacio; Miranda-Zapata, Edgardo


    This study examined longitudinal measurement invariance in the Satisfaction with Food-related Life (SWFL) scale using follow-up data from university students. We examined this measure of the SWFL in different groups of students, separated by various characteristics. Through non-probabilistic long...

  1. Planck early results. XI. Calibration of the local galaxy cluster Sunyaev-Zeldovich scaling relations

    DEFF Research Database (Denmark)

    Poutanen, T.; Natoli, P.; Polenta, G.


    signal analogue YX,500 = Mg,500 × TX, and total mass M500. After correction for the effect of selection bias on the scaling relations, we find results that are in excellent agreement with both X-ray predictions and recently-published ground-based data derived from smaller samples. The present data yield...

  2. Psychometric properties of the Gambling Related Cognitions Scale (GRCS) in young Italian gamblers. (United States)

    Donati, Maria Anna; Ancona, Francesco; Chiesi, Francesca; Primi, Caterina


    The involvement in gambling activities is increasing among adolescents, together with the risk of developing gambling problems. Given the important role of erroneous beliefs on adolescent problematic gambling behavior, the aim of this study was to investigate the adequacy of the Gambling Related Cognitions Scale (GRCS; Raylu & Oei, 2004) to assess gambling-related distortions among youth in Italy. The scale was administered to 1656 Italian high school students (65% males, mean age=16.15 years, SD=1.44), and analyses were carried out with respondents who have gambled during the previous year (N=1224). The adequacy of the five-factor model was confirmed (both among male and female adolescent gamblers), as well as the reliability of the total scale and subscales. Evidence for the validity of the GRCS among adolescents was provided confirming the relationship between gambling-related cognitions and problem gambling found in previous studies. Research on the validity of the scale was also extended by investigating the relationship between cognitive distortions about gambling and the frequency of engaging in different gambling activities. Our results confirm that the GRCS is an effective multidimensional instrument which accurately measures young gamblers' cognitive distortions relating to gambling. As such, it can be used as a useful tool in the assessment and treatment of juvenile gambling. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. How covalence breaks adsorption-energy scaling relations and solvation restores them

    DEFF Research Database (Denmark)

    Vallejo, Federico Calle; Krabbe, Alexander; García Lastra, Juan Maria


    It is known that breaking the scaling relations between the adsorption energies of *O, *OH, and *OOH is paramount in catalyzing more efficiently the reduction of O2 in fuel cells and its evolution in electrolyzers. Taking metalloporphyrins as a case study, we evaluate here the adsorption energies...

  4. Physical and chemical nature of the scaling relations between adsorption energies of atoms on metal surfaces

    DEFF Research Database (Denmark)

    Calle-Vallejo, F.; Martínez, J. I.; García Lastra, Juan Maria


    Despite their importance in physics and chemistry, the origin and extent of the scaling relations between the energetics of adsorbed species on surfaces remain elusive. We demonstrate here that scalability is not exclusive to adsorbed atoms and their hydrogenated species but rather a general phen...

  5. Global-Scale Location and Distance Estimates: Common Representations and Strategies in Absolute and Relative Judgments (United States)

    Friedman, Alinda; Montello, Daniel R.


    The authors examined whether absolute and relative judgments about global-scale locations and distances were generated from common representations. At the end of a 10-week class on the regional geography of the United States, participants estimated the latitudes of 16 North American cities and all possible pairwise distances between them. Although…

  6. Scaling relations in early-type galaxies from integral-field stellar kinematics

    NARCIS (Netherlands)

    Cappellari, M.; Scott, N.; Alatalo, K.; Blitz, L.; Bois, M.; Bournaud, F.; Bureau, M.; Davies, R. L.; Davis, T. A.; de Zeeuw, P. T.; Emsellem, E.; Falcon-Barroso, J.; Khochfar, S.; Krajnovic, D.; Kuntschner, H.; Lablanche, P. -Y; McDermid, R. M.; Morganti, R.; Naab, T.; Sarzi, M.; Serra, P.; van den Bosch, R.C.E.; van de Ven, G.; Weijmans, A.; Young, L. M.


    Early-type galaxies (ETGs) satisfy a now classic scaling relation Re ∝ σ1.2eI‑0.8e, the Fundamental Plane (FP; Djorgovski & Davis 1987; Dressler et al. 1987), between their size, stellar velocity dispersion and mean surface brightness. A significant effort has been devoted in the past twenty years

  7. The spatial extent of rainfall events and its relation to precipitation scaling

    NARCIS (Netherlands)

    Lochbihler, K.U.; Lenderink, Geert; Siebesma, A.P.


    Observations show that subdaily precipitation extremes increase with dew point temperature at a rate exceeding the Clausius-Clapeyron (CC) relation. The understanding of this so-called super CC scaling is still incomplete, and observations of convective cell properties could provide important

  8. Galactic bulges from Hubble Space Telescope NICMOS observations : Global scaling relations

    NARCIS (Netherlands)

    Balcells, Marc; Graham, Alister W.; Peletier, Reynier F.


    We investigate bulge and disk scaling relations using a volume-corrected sample of early-to intermediate-type disk galaxies in which, importantly, the biasing flux from additional nuclear components has been modeled and removed. Structural parameters are obtained from a seeing-convolved, bulge +

  9. Permeability estimation for heavy oil reservoir: an alternative approach to avoid misleading tendencies

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, L. [PDVSA (Venezuela)


    In oil production, characterization of the reservoir has to be undertaken in order to optimize the hydrocarbon production rate. Permeability is one of the most important parameters of a reservoir but estimation is difficult in heavy oil reservoirs and requires the use of multiple techniques. The objective of this paper was to evaluate the results of implementing a multi-scale permeability estimation method. Scale support effect and the physics of the measurements were looked into through a study which was conducted in Venezuela on two of PDVSA's fields, the Cerro Negro Field and the Morichal Field. Results showed that the proposed methodology captured efficiently the influence of parameters on permeability production and was successful in removing the local bias from the permeability data. The multi scale permeability estimation methodology was shown to address the issues encountered with a unique approach and to provide excellent results.

  10. Use of DMPC and DSPC lipids for verapamil and naproxen permeability studies by PAMPA. (United States)

    Alvarez-Figueroa, M J; Contreras-Garrido, B C; Soto-Arriaza, M A


    Verapamil and naproxen Parallel Artificial Membrane Permeability Assay (PAMPA) permeability was studied using lipids not yet reported for this model in order to facilitate the quantification of drug permeability. These lipids are 1,2-distearoyl-sn-glycero-3-phosphatidylcholine (DSPC), 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and an equimolar mixture of DMPC/DSPC, both in the absence and in the presence of 33.3 mol% of cholesterol. PAMPA drug permeability using the lipids mentioned above was compared with lecithin-PC. The results show that verapamil permeability depends on the kind of lipid used, in the order DMPC > DMPC/DSPC > DSPC. The permeability of the drugs was between 1.3 and 3.5-times larger than those obtained in lecithin-PC for all the concentrations of the drug used. Naproxen shows similar permeability than verapamil; however, the permeability increased with respect to lecithin-PC only when DMPC and DMPC/DSPC were used. This behavior could be explained by a difference between the drug net charge at pH 7.4. On the other hand, in the presence of cholesterol, verapamil permeability increases in all lipid systems; however, the relative verapamil permeability respect to lecithin-PC did not show any significant increase. This result is likely due to the promoting effect of cholesterol, which is not able to compensate for the large increase in verapamil permeability observed in lecithin-PC. With respect to naproxen, its permeability value and relative permeability respect lecithin-PC not always increased in the presence of cholesterol. This result is probably attributed to the negative charge of naproxen rather than its molecular weight. The lipid systems studied have an advantage in drug permeability quantification, which is mainly related to the charge of the molecule and not to its molecular weight or to cholesterol used as an absorption promoter.

  11. Peer relations scale for adolescents treated for substance use disorder: a factor analytic presentation. (United States)

    Yao, Ping; Ciesla, James R; Mazurek, Kathryn D; Spear, Sherilynn F


    The literature indicates that peer relations are an important aspect of the treatment and recovery of adolescents with substance use disorder (SUD). Unfortunately, no standard measure of peer relations exists. The objective of this research is to use exploratory factor analysis to examine the underlying factor structure of a 14-item peer relations scale for use in this treatment population. Participants are 509 adolescents discharged from primary substance abuse treatment from 2003-2010. The data are from research conducted between six and twelve months post discharge via a 230-item questionnaire that included the 14-item peer relations scale. The scale has questions that assess the degree to which the adolescent's social contacts conform to norms of positive behavior and therefore foster non-use and recovery. The response rate was 62%. The scale was decomposed by principal component factor analysis. When the matrix was rotated by varimax a three factor solution explaining 99.99% of the common variance emerged. The first factor yielded ten items that measure association with peers who engage in positive versus delinquent social behavior (positive versus negative social behavior). The three items in the second factor specify association with peers who use versus those who don't use drugs, and thereby encourage recovery and discourage drug use (drug use). The third and factor contained two items measuring the degree to which the recovering adolescent associates with new or previous friends (post treatment peer association). This scale is useful as a standard measure in that it begins to identify the measurable dimensions of peer relations that influence sustaining post treatment recovery.

  12. Peer relations scale for adolescents treated for substance use disorder: a factor analytic presentation

    Directory of Open Access Journals (Sweden)

    Yao Ping


    Full Text Available Abstract Background The literature indicates that peer relations are an important aspect of the treatment and recovery of adolescents with substance use disorder (SUD. Unfortunately, no standard measure of peer relations exists. The objective of this research is to use exploratory factor analysis to examine the underlying factor structure of a 14-item peer relations scale for use in this treatment population. Methods Participants are 509 adolescents discharged from primary substance abuse treatment from 2003–2010. The data are from research conducted between six and twelve months post discharge via a 230-item questionnaire that included the 14-item peer relations scale. The scale has questions that assess the degree to which the adolescent's social contacts conform to norms of positive behavior and therefore foster non-use and recovery. The response rate was 62%. Results The scale was decomposed by principal component factor analysis. When the matrix was rotated by varimax a three factor solution explaining 99.99% of the common variance emerged. The first factor yielded ten items that measure association with peers who engage in positive versus delinquent social behavior (positive versus negative social behavior. The three items in the second factor specify association with peers who use versus those who don’t use drugs, and thereby encourage recovery and discourage drug use (drug use. The third and factor contained two items measuring the degree to which the recovering adolescent associates with new or previous friends (post treatment peer association. Conclusions This scale is useful as a standard measure in that it begins to identify the measurable dimensions of peer relations that influence sustaining post treatment recovery.

  13. Mitigating the mass dependence in the Δν scaling relation of red giant stars (United States)

    Guggenberger, Elisabeth; Hekker, Saskia; Angelou, George C.; Basu, Sarbani; Bellinger, Earl P.


    The masses and radii of solar-like oscillators can be estimated through the asteroseismic scaling relations. These relations provide a direct link between observables, I.e. effective temperature and characteristics of the oscillation spectra, and stellar properties, I.e. mean density and surface gravity (thus mass and radius). These scaling relations are commonly used to characterize large samples of stars. Usually, the Sun is used as a reference from which the structure is scaled. However, for stars that do not have a similar structure as the Sun, using the Sun as a reference introduces systematic errors as large as 10 per cent in mass and 5 per cent in radius. Several alternatives for the reference of the scaling relation involving the large frequency separation (typical frequency difference between modes of the same degree and consecutive radial order) have been suggested in the literature. In a previous paper, we presented a reference function with a dependence on both effective temperature and metallicity. The accuracy of predicted masses and radii improved considerably when using reference values calculated from our reference function. However, the residuals indicated that stars on the red giant branch possess a mass dependence that was not accounted for. Here, we present a reference function for the scaling relation involving the large frequency separation that includes the mass dependence. This new reference function improves the derived masses and radii significantly by removing the systematic differences and mitigates the trend with νmax (frequency of maximum oscillation power) that exists when using the solar value as a reference.

  14. Scale-Dependent Assessment of Relative Disease Resistance to Plant Pathogens

    Directory of Open Access Journals (Sweden)

    Peter Skelsey


    Full Text Available Phenotyping trials may not take into account sufficient spatial context to infer quantitative disease resistance of recommended varieties in commercial production settings. Recent ecological theory—the dispersal scaling hypothesis—provides evidence that host heterogeneity and scale of host heterogeneity interact in a predictable and straightforward manner to produce a unimodal (“humpbacked” distribution of epidemic outcomes. This suggests that the intrinsic artificiality (scale and design of experimental set-ups may lead to spurious conclusions regarding the resistance of selected elite cultivars, due to the failure of experimental efforts to accurately represent disease pressure in real agricultural situations. In this model-based study we investigate the interaction of host heterogeneity and scale as a confounding factor in the inference from ex-situ assessment of quantitative disease resistance to commercial production settings. We use standard modelling approaches in plant disease epidemiology and a number of different agronomic scenarios. Model results revealed that the interaction of heterogeneity and scale is a determinant of relative varietal performance under epidemic conditions. This is a previously unreported phenomenon that could provide a new basis for informing the design of future phenotyping platforms, and optimising the scale at which quantitative disease resistance is assessed.

  15. Use of Interface Treatment to Reduce Emissions from Residuals in Lower Permeability Zones to Groundwater flowing Through More Permeable Zones (Invited) (United States)

    Johnson, P.; Cavanagh, B.; Clifton, L.; Daniels, E.; Dahlen, P.


    Many soil and groundwater remediation technologies rely on fluid flow for contaminant extraction or reactant delivery (e.g., soil vapor extraction, pump and treat, in situ chemical oxidation, air sparging, enhanced bioremediation). Given that most unconsolidated and consolidated settings have permeability contrasts, the outcome is often preferential treatment of more permeable zones and ineffective treatment of the lower permeability zones. When this happens, post-treatment contaminant emissions from low permeability zone residuals can cause unacceptable long-term impacts to groundwater in the transmissive zones. As complete remediation of the impacted lower permeability zones may not be practicable with conventional technologies, one might explore options that lead to reduction of the contaminant emissions to acceptable levels, rather than full remediation of the lower permeability layers. This could be accomplished either by creating a sustained emission reaction/attenuation zone at the high-low permeability interface, or by creating a clean soil zone extending sufficiently far into the lower permeability layer to cause the necessary reduction in contaminant concentration gradient and diffusive emission. These options are explored in proof-of-concept laboratory-scale physical model experiments. The physical models are prepared with two layers of contrasting permeability and either dissolved matrix storage or nonaqueous phase liquid (NAPL) in the lower permeability layer. A dissolved oxidant is then delivered to the interface via flow across the higher permeability layer and changes in contaminant emissions from the low permeability zone are monitored before, during, and after oxidant delivery. The use of three oxidants (dissolved oxygen, hydrogen peroxide and sodium persulfate) for treatment of emissions from petroleum hydrocarbon residuals is examined.

  16. Scaling Relations of Local Magnitude versus Moment Magnitude for Sequences of Similar Earthquakes in Switzerland

    KAUST Repository

    Bethmann, F.


    Theoretical considerations and empirical regressions show that, in the magnitude range between 3 and 5, local magnitude, ML, and moment magnitude, Mw, scale 1:1. Previous studies suggest that for smaller magnitudes this 1:1 scaling breaks down. However, the scatter between ML and Mw at small magnitudes is usually large and the resulting scaling relations are therefore uncertain. In an attempt to reduce these uncertainties, we first analyze the ML versus Mw relation based on 195 events, induced by the stimulation of a geothermal reservoir below the city of Basel, Switzerland. Values of ML range from 0.7 to 3.4. From these data we derive a scaling of ML ~ 1:5Mw over the given magnitude range. We then compare peak Wood-Anderson amplitudes to the low-frequency plateau of the displacement spectra for six sequences of similar earthquakes in Switzerland in the range of 0:5 ≤ ML ≤ 4:1. Because effects due to the radiation pattern and to the propagation path between source and receiver are nearly identical at a particular station for all events in a given sequence, the scatter in the data is substantially reduced. Again we obtain a scaling equivalent to ML ~ 1:5Mw. Based on simulations using synthetic source time functions for different magnitudes and Q values estimated from spectral ratios between downhole and surface recordings, we conclude that the observed scaling can be explained by attenuation and scattering along the path. Other effects that could explain the observed magnitude scaling, such as a possible systematic increase of stress drop or rupture velocity with moment magnitude, are masked by attenuation along the path.

  17. Porosity and permeability determination of organic-rich Posidonia shales based on 3-D analyses by FIB-SEM microscopy (United States)

    Grathoff, Georg H.; Peltz, Markus; Enzmann, Frieder; Kaufhold, Stephan


    The goal of this study is to better understand the porosity and permeability in shales to improve modelling fluid and gas flow related to shale diagenesis. Two samples (WIC and HAD) were investigated, both mid-Jurassic organic-rich Posidonia shales from Hils area, central Germany of different maturity (WIC R0 0.53 % and HAD R0 1.45 %). The method for image collection was focused ion beam (FIB) microscopy coupled with scanning electron microscopy (SEM). For image and data analysis Avizo and GeoDict was used. Porosity was calculated from segmented 3-D FIB based images and permeability was simulated by a Navier Stokes-Brinkman solver in the segmented images. Results show that the quantity and distribution of pore clusters and pores (≥ 40 nm) are similar. The largest pores are located within carbonates and clay minerals, whereas the smallest pores are within the matured organic matter. Orientation of the pores calculated as pore paths showed minor directional differences between the samples. Both samples have no continuous connectivity of pore clusters along the axes in the x, y, and z direction on the scale of 10 to 20 of micrometer, but do show connectivity on the micrometer scale. The volume of organic matter in the studied volume is representative of the total organic carbon (TOC) in the samples. Organic matter does show axis connectivity in the x, y, and z directions. With increasing maturity the porosity in organic matter increases from close to 0 to more than 5 %. These pores are small and in the large organic particles have little connection to the mineral matrix. Continuous pore size distributions are compared with mercury intrusion porosimetry (MIP) data. Differences between both methods are caused by resolution limits of the FIB-SEM and by the development of small pores during the maturation of the organic matter. Calculations show no permeability when only considering visible pores due to the lack of axis connectivity. Adding the organic matter with a

  18. The permeability of oral leukoplakia. (United States)

    Bánóczy, Jolán; Squier, Christopher A; Kremer, Mary; Wertz, Philip W; Kövesi, György; Szende, Béla; Dombi, Csaba


    The significant increase in oral cancer mortality necessitates further research on the mechanisms of tumorigenesis. It was the aim of this study to compare the permeability, lipid composition and histopathological characteristics of oral leukoplakia with non-lesional specimens of the same region in 30 cases as well as 11 specimens originating from healthy control buccal mucosa. The permeability (Kp) of tissue biopsies to tritiated nitrosonornicotine was determined in a continuous through-flow perfusion system, lipids were extracted and identified by thin-layer chromatography, and thickness of epithelium and keratin layer assessed by histopathological methods. Results of the measurements showed that the permeability to the tobacco carcinogen, nitrosonornicotine for leukoplakic tissue was higher than for normal control buccal specimens. Non-lesional areas of buccal mucosa, adjacent to leukoplakias, showed hyperplasia and significantly higher permeability values than both leukoplakic and normal buccal control mucosa. The lipid content of the non-lesional sites was intermediate between the increased values of the leukoplakic lesion and of normal control mucosa. The data strongly suggest that the presence of tobacco in the oral cavity may bring about generalized changes even in regions that do not show leukoplakia.

  19. Identifying time scales for violation/preservation of Stokes-Einstein relation in supercooled water. (United States)

    Kawasaki, Takeshi; Kim, Kang


    The violation of the Stokes-Einstein (SE) relation D ~ (η/T)-1 between the shear viscosity η and the translational diffusion constant D at temperature T is of great importance for characterizing anomalous dynamics of supercooled water. Determining which time scales play key roles in the SE violation remains elusive without the measurement of η. We provide comprehensive simulation results of the dynamic properties involving η and D in the TIP4P/2005 supercooled water. This enabled the thorough identification of the appropriate time scales for the SE relation Dη/T. In particular, it is demonstrated that the temperature dependence of various time scales associated with structural relaxation, hydrogen bond breakage, stress relaxation, and dynamic heterogeneities can be definitely classified into only two classes. That is, we propose the generalized SE relations that exhibit "violation" or "preservation." The classification depends on the examined time scales that are coupled or decoupled with the diffusion. On the basis of the classification, we explain the physical origins of the violation in terms of the increase in the plateau modulus and the nonexponentiality of stress relaxation. This implies that the mechanism of SE violation is attributed to the attained solidity upon supercooling, which is in accord with the growth of non-Gaussianity and spatially heterogeneous dynamics.

  20. Constraints on Dark Energy, Observable-mass Scaling Relations, Neutrino Properties and Gravity from Galaxy Clusters

    DEFF Research Database (Denmark)

    Rapetti Serra, David Angelo

    Using a data set of 238 cluster detections drawn from the ROSAT All-Sky Survey and X-ray follow-up observations from the Chandra X-ray Observatory and/or ROSAT for 94 of those clusters we obtain tight constraints on dark energy, both luminosity-mass and temperature-mass scaling relations, neutrino...... properties and gravity. I will present the novel statistical framework we employed to self-consistently and simultaneously constrain cosmology and observable-mass scaling relations accounting for survey biases, parameter covariances and systematic uncertainties. Allowing the dark energy equation of state...... and the linear growth index to take any constant values, we find no evidence for departures from the standard cosmological paradigm – General Relativity plus a cosmological constant and cold dark matter. I will review in detail our results and demonstrate the power of X-ray cluster studies to constrain both...

  1. Measuring emotions during epistemic activities: the Epistemically-Related Emotion Scales. (United States)

    Pekrun, Reinhard; Vogl, Elisabeth; Muis, Krista R; Sinatra, Gale M


    Measurement instruments assessing multiple emotions during epistemic activities are largely lacking. We describe the construction and validation of the Epistemically-Related Emotion Scales, which measure surprise, curiosity, enjoyment, confusion, anxiety, frustration, and boredom occurring during epistemic cognitive activities. The instrument was tested in a multinational study of emotions during learning from conflicting texts (N = 438 university students from the United States, Canada, and Germany). The findings document the reliability, internal validity, and external validity of the instrument. A seven-factor model best fit the data, suggesting that epistemically-related emotions should be conceptualised in terms of discrete emotion categories, and the scales showed metric invariance across the North American and German samples. Furthermore, emotion scores changed over time as a function of conflicting task information and related significantly to perceived task value and use of cognitive and metacognitive learning strategies.

  2. Clamshell excavation of a permeable reactive barrier (United States)

    Molfetta, Antonio Di; Sethi, Rajandrea


    Nowadays, permeable reactive barriers (PRB) are one of the most widespread techniques for the remediation of contaminated aquifers. Over the past 10 years, the use of iron-based PRBs has evolved from innovative to accepted standard practice for the treatment of a variety of groundwater contaminants (ITRC in: Permeable reactive barriers: lessons learned/new directions. The Interstate Technology and Regulatory Council, Permeable Reactive Barriers Team 2005). Although, a variety of excavation methods have been developed, backhoe excavators are often used for the construction of PRBs. The aim of this study is to describe the emplacement of a full-scale PRB and the benefits deriving from the use of a crawler crane equipped with a hydraulic grab (also known as clamshell excavator) in the excavation phases. The studied PRB was designed to remediate a chlorinated hydrocarbons plume at an old industrial landfill site, in Avigliana, near the city of Torino, in Italy. The continuous reactive barrier was designed to be 120 m long, 13 m deep, and 0.6 m thick. The installation of the barrier was accomplished using a clamshell for the excavation of the trench and a guar-gum slurry to support the walls. The performance of this technique was outstanding and allowed the installation of the PRB in 7 days. The degree of precision of the excavation was very high because of the intrinsic characteristics of this excavation tool and of the use of a concrete curb to guide the hydraulic grab. Moreover, the adopted technique permitted a saving of bioslurry thus minimizing the amount of biocide required.

  3. Hillslopes to Hollows to Channels: Identifying Process Transitions and Domains using Characteristic Scaling Relations (United States)

    Williams, K.; Locke, W. W.


    Headwater catchments are partitioned into hillslopes, unchanneled valleys (hollows), and channels. Low order (less than or equal to two) channels comprise most of the stream length in the drainage network so defining where hillslopes end and hollows begin, and where hollows end and channels begin, is important for calibration and verification of hydrologic runoff and sediment production modeling. We test the use of landscape scaling relations to detect flow regimes characteristic of diffusive, concentrated, and incisive runoff, and use these flow regimes as proxies for hillslope, hollow, and channeled landforms. We use LiDAR-derived digital elevation models (DEMs) of two pairs of headwater catchments in southwest and north-central Montana to develop scaling relations of flowpath length, total stream power, and contributing area. The catchment pairs contrast low versus high drainage density and north versus south aspect. Inflections in scaling relations of contributing area and flowpath length in a single basin (modified Hack's law) and contributing area and total stream power were used to identify hillslope and fluvial process domain transitions. In the modified Hack's law, inflections in the slope of the log-log power law are hypothesized to correspond to changes in flow regime used as proxies for hillslope, hollow, and channeled landforms. Similarly, rate of change of total stream power with contributing area is hypothesized to become constant and then decrease at the hillslope to fluvial domain transition. Power law scaling of frequency-magnitude plots of curvature and an aspect-related parameter were also tested as an indicator of the transition from scale-dependent hillslope length to the scale invariant fluvial domain. Curvature and aspect were calculated at each cell in spectrally filtered DEMs. Spectral filtering by fast Fourier and wavelet transforms enhances detection of fine-scale fluvial features by removing long wavelength topography. Using the

  4. Scaling Green-Kubo Relation and Application to Three Aging Systems

    Directory of Open Access Journals (Sweden)

    A. Dechant


    Full Text Available The Green-Kubo formula relates the spatial diffusion coefficient to the stationary velocity autocorrelation function. We derive a generalization of the Green-Kubo formula that is valid for systems with long-range or nonstationary correlations for which the standard approach is no longer valid. For the systems under consideration, the velocity autocorrelation function ⟨v(t+τv(t⟩ asymptotically exhibits a certain scaling behavior and the diffusion is anomalous, ⟨x^{2}(t⟩≃2D_{ν}t^{ν}. We show how both the anomalous diffusion coefficient D_{ν} and the exponent ν can be extracted from this scaling form. Our scaling Green-Kubo relation thus extends an important relation between transport properties and correlation functions to generic systems with scale-invariant dynamics. This includes stationary systems with slowly decaying power-law correlations, as well as aging systems, systems whose properties depend on the age of the system. Even for systems that are stationary in the long-time limit, we find that the long-time diffusive behavior can strongly depend on the initial preparation of the system. In these cases, the diffusivity D_{ν} is not unique, and we determine its values, respectively, for a stationary or nonstationary initial state. We discuss three applications of the scaling Green-Kubo relation: free diffusion with nonlinear friction corresponding to cold atoms diffusing in optical lattices, the fractional Langevin equation with external noise recently suggested to model active transport in cells, and the Lévy walk with numerous applications, in particular, blinking quantum dots. These examples underline the wide applicability of our approach, which is able to treat very different mechanisms of anomalous diffusion.

  5. Cosmological special relativity the large scale structure of space, time and velocity

    CERN Document Server

    Carmeli, Moshe


    This book deals with special relativity theory and its application to cosmology. It presents Einstein's theory of space and time in detail, and describes the large scale structure of space, time and velocity as a new cosmological special relativity. A cosmological Lorentz-like transformation, which relates events at different cosmic times, is derived and applied. A new law of addition of cosmic times is obtained, and the inflation of the space at the early universe is derived, both from the cosmological transformation. The book will be of interest to cosmologists, astrophysicists, theoretical

  6. Gauge-Independent Scales Related to the Standard Model Vacuum Instability

    CERN Document Server

    Espinosa, Jose R.; Konstandin, Thomas; Riotto, Antonio


    The measured (central) values of the Higgs and top quark masses indicate that the Standard Model (SM) effective potential develops an instability at high field values. The scale of this instability, determined as the Higgs field value at which the potential drops below the electroweak minimum, is about $10^{11}$ GeV. However, such a scale is unphysical as it is not gauge-invariant and suffers from a gauge-fixing uncertainty of up to two orders of magnitude. Subjecting our system, the SM, to several probes of the instability (adding higher order operators to the potential; letting the vacuum decay through critical bubbles; heating up the system to very high temperature; inflating it) and asking in each case physical questions, we are able to provide several gauge-invariant scales related with the Higgs potential instability.

  7. The spatial extent of rainfall events and its relation to precipitation scaling (United States)

    Lochbihler, Kai; Lenderink, Geert; Siebesma, A. Pier


    Observations show that subdaily precipitation extremes increase with dew point temperature at a rate exceeding the Clausius-Clapeyron (CC) relation. The understanding of this so-called super CC scaling is still incomplete, and observations of convective cell properties could provide important information. Here the size and intensity of rain cells are investigated by using a tracking of rainfall events in high-resolution radar data. Higher intensities are accompanied by larger rainfall areas. However, whereas small rain cells mainly follow CC scaling, larger cells display super CC behavior. Even more, for dew point exceeding 15°C, the rain cell size has to increase in order to sustain super CC scaling and a remarked increase in rain cell area is found. Our results imply that the source area of moisture, the cloud size, and the degree of mesoscale organization play key roles in the context of a warming climate.

  8. Internal consistency of the object relations and social cognition scales for the Thematic Apperception Test. (United States)

    Hibbard, S; Mitchell, D; Porcerelli, J


    We examined 8 data sets to determine whether it is possible to attain acceptable levels of internal consistency (coefficient alpha) reliability for the 4 Object Relations and Social Cognition scales (ORSC; Westen, Lohr, Silk, Kerber, & Goodrich, 1989) for the Thematic Apperception Test (TAT; Murray, 1943) when cards are considered as items in a scale. Number of cards used in the data sets ranged from 4 to 10, and the Spearman-Brown prophecy formula was applied to estimate the number of cards that would be required to attain alpha levels of different magnitudes. The two more structural subscales (Complexity of Representations and Understanding of Social Causality) have somewhat higher consistencies than the two more affective ones (Affect Tone and Capacity for Emotional Investment and Moral Standards). The results suggest that the use of 10 to 12 cards provides internal consistencies of alpha > or = .70 across each of the 4 ORSC scales.

  9. Exploring the relation between bullying and homophobic verbal content: the homophobic content agent target (HCAT) scale. (United States)

    Poteat, V Paul; Espelage, Dorothy L


    This investigation quantitatively examines the association among homophobic content, bullying, victimization, empathy, and several psychosocial outcomes of these constructs. The 2-factor Homophobic Content Agent Target (HCAT) scale was developed and validated among 191 middle school students to assess the extent to which students both use and are called various epithets in reference to sexual orientation. Cronbach reliability coefficients of alpha = .85 were obtained for both factors. Convergent validity was demonstrated with scales measuring bullying, fighting, victimization, relational aggression and victimization, anxiety and depression, and delinquency. Discriminant validity was demonstrated in comparison with school sense of belonging, empathy, and perspective-taking. Discriminative validity was demonstrated through sex differences on several scales. Results strongly suggest that homophobic content is prevalent in various forms of aggression and victimization, and that future research should examine the role of homophobia in bullying and victimization in schools.

  10. Permeability model of sintered porous media: analysis and experiments (United States)

    Flórez Mera, Juan Pablo; Chiamulera, Maria E.; Mantelli, Marcia B. H.


    In this paper, the permeability of porous media fabricated from copper powder sintering process was modeled and measured, aiming the use of the porosity as input parameter for the prediction of the permeability of sintering porous media. An expression relating the powder particle mean diameter with the permeability was obtained, based on an elementary porous media cell, which is physically represented by a duct formed by the arrangement of spherical particles forming a simple or orthorhombic packing. A circular duct with variable section was used to model the fluid flow within the porous media, where the concept of the hydraulic diameter was applied. Thus, the porous is modeled as a converging-diverging duct. The electrical circuit analogy was employed to determine two hydraulic resistances of the cell: based on the Navier-Stokes equation and on the Darcýs law. The hydraulic resistances are compared between themselves and an expression to determine the permeability as function of average particle diameter is obtained. The atomized copper powder was sifted to reduce the size dispersion of the particles. The porosities and permeabilities of sintered media fabricated from powders with particle mean diameters ranging from 20 to 200 microns were measured, by means of the image analysis method and using an experimental apparatus. The permeability data of a porous media, made of copper powder and saturated with distilled water, was used to compare with the permeability model. Permeability literature models, which considers that powder particles have the same diameter and include porosity data as input parameter, were compared with the present model and experimental data. This comparison showed to be quite good.

  11. Permeability model of sintered porous media: analysis and experiments (United States)

    Flórez Mera, Juan Pablo; Chiamulera, Maria E.; Mantelli, Marcia B. H.


    In this paper, the permeability of porous media fabricated from copper powder sintering process was modeled and measured, aiming the use of the porosity as input parameter for the prediction of the permeability of sintering porous media. An expression relating the powder particle mean diameter with the permeability was obtained, based on an elementary porous media cell, which is physically represented by a duct formed by the arrangement of spherical particles forming a simple or orthorhombic packing. A circular duct with variable section was used to model the fluid flow within the porous media, where the concept of the hydraulic diameter was applied. Thus, the porous is modeled as a converging-diverging duct. The electrical circuit analogy was employed to determine two hydraulic resistances of the cell: based on the Navier-Stokes equation and on the Darcýs law. The hydraulic resistances are compared between themselves and an expression to determine the permeability as function of average particle diameter is obtained. The atomized copper powder was sifted to reduce the size dispersion of the particles. The porosities and permeabilities of sintered media fabricated from powders with particle mean diameters ranging from 20 to 200 microns were measured, by means of the image analysis method and using an experimental apparatus. The permeability data of a porous media, made of copper powder and saturated with distilled water, was used to compare with the permeability model. Permeability literature models, which considers that powder particles have the same diameter and include porosity data as input parameter, were compared with the present model and experimental data. This comparison showed to be quite good.

  12. The Y SZ-YX Scaling Relation as Determined from Planck and Chandra (United States)

    Rozo, Eduardo; Vikhlinin, Alexey; More, Surhud


    Sunyaev-Zeldovich (SZ) clusters surveys, such as Planck, the South Pole Telescope, and the Atacama Cosmology Telescope, will soon be publishing several hundred SZ-selected systems. The key ingredient required to transport the mass calibration from current X-ray-selected cluster samples to these SZ systems is the Y SZ-YX scaling relation. We constrain the amplitude, slope, and scatter of the Y SZ-YX scaling relation using SZ data from Planck and X-ray data from Chandra. We find a best-fit amplitude of ln (D 2 A Y SZ/CYX ) = -0.202 ± 0.024 at the pivot point CYX = 8 × 10-5 Mpc2. This corresponds to a Y SZ/YX ratio of 0.82 ± 0.024, in good agreement with X-ray expectations after including the effects of gas clumping. The slope of the relation is α = 0.916 ± 0.032, consistent with unity at ≈2.3σ. We are unable to detect intrinsic scatter, and find no evidence that the scaling relation depends on cluster dynamical state.

  13. The development and validation of the Relational Self-Esteem Scale. (United States)

    Du, Hongfei; King, Ronnel B; Chi, Peilian


    According to the tripartite model of the self (Brewer & Gardner, 1996), the self consists of three aspects: personal, relational, and collective. Correspondingly, individuals can achieve a sense of self-worth through their personal attributes (personal self-esteem), relationship with significant others (relational self-esteem), or social group membership (collective self-esteem). Existing measures on personal and collective self-esteem are available in the literature; however, no scale exists that assesses relational self-esteem. The authors developed a scale to measure individual differences in relational self-esteem and tested it with two samples of Chinese university students. Between and within-network approaches to construct validation were used. The scale showed adequate internal consistency reliability and results of the confirmatory factor analysis showed good fit. It also exhibited meaningful correlations with theoretically relevant constructs in the nomological network. Implications and directions for future research are discussed. © 2012 The Authors. Scandinavian Journal of Psychology © 2012 The Scandinavian Psychological Associations.

  14. Evaluating broad scale patterns among related species using resource experiments in tropical hummingbirds. (United States)

    Weinstein, Ben G; Graham, Catherine H


    A challenge in community ecology is connecting biogeographic patterns with local scale observations. In Neotropical hummingbirds, closely related species often co-occur less frequently than expected (overdispersion) when compared to a regional species pool. While this pattern has been attributed to interspecific competition, it is important to connect these findings with local scale mechanisms of coexistence. We measured the importance of the presence of competitors and the availability of resources on selectivity at experimental feeders for Andean hummingbirds along a wide elevation gradient. Selectivity was measured as the time a bird fed at a feeder with a high sucrose concentration when presented with feeders of both low and high sucrose concentrations. Resource selection was measured using time-lapse cameras to identity which floral resources were used by each hummingbird species. We found that the increased abundance of preferred resources surrounding the feeder best explained increased species selectivity, and that related hummingbirds with similar morphology chose similar floral resources. We did not find strong support for direct agonism based on differences in body size or phylogenetic relatedness in predicting selectivity. These results suggest closely related hummingbird species have overlapping resource niches, and that the intensity of interspecific competition is related to the abundance of those preferred resources. If these competitive interactions have negative demographic effects, our results could help explain the pattern of phylogenetic overdispersion observed at regional scales. © 2016 by the Ecological Society of America.

  15. A Kennicutt-Schmidt relation at molecular cloud scales and beyond (United States)

    Khoperskov, Sergey A.; Vasiliev, Evgenii O.


    Using N-body/gasdynamic simulations of a Milky Way-like galaxy, we analyse a Kennicutt-Schmidt (KS) relation, Σ _SFR ∝ Σ _gas^N, at different spatial scales. We simulate synthetic observations in CO lines and ultraviolet (UV) band. We adopt the star formation rate (SFR) defined in two ways: based on free fall collapse of a molecular cloud - ΣSFR, cl, and calculated by using a UV flux calibration - ΣSFR,UV. We study a KS relation for spatially smoothed maps with effective spatial resolution from molecular cloud scales to several hundred parsecs. We find that for spatially and kinematically resolved molecular clouds the Σ _{SFR, cl} ∝ σ _{gas}^N relation follows the power law with index N ≈ 1.4. Using UV flux as SFR calibrator, we confirm a systematic offset between the ΣSFR,UV and Σgas distributions on scales compared to molecular cloud sizes. Degrading resolution of our simulated maps for surface densities of gas and SFRs, we establish that there is no relation ΣSFR,UV -Σgas below the resolution ˜50 pc. We find a transition range around scales ˜50-120 pc, where the power-law index N increases from 0 to 1-1.8 and saturates for scales larger ˜120 pc. A value of the index saturated depends on a surface gas density threshold and it becomes steeper for higher Σgas threshold. Averaging over scales with size of ≳ 150 pc the power-law index N equals 1.3-1.4 for surface gas density threshold ˜5 M⊙ pc-2. At scales ≳ 120 pc surface SFR densities determined by using CO data and UV flux, ΣSFR,UV/SFR, cl, demonstrate a discrepancy about a factor of 3. We argue that this may be originated from overestimating (constant) values of conversion factor, star formation efficiency or UV calibration used in our analysis.

  16. Large Scale Water Vapor Sources Relative to the October 2000 Piedmont Flood (United States)

    Turato, Barbara; Reale, Oreste; Siccardi, Franco


    Very intense mesoscale or synoptic-scale rainfall events can occasionally be observed in the Mediterranean region without any deep cyclone developing over the areas affected by precipitation. In these perplexing cases the synoptic situation can superficially look similar to cases in which very little precipitation occurs. These situations could possibly baffle the operational weather forecasters. In this article, the major precipitation event that affected Piedmont (Italy) between 13 and 16 October 2000 is investigated. This is one of the cases in which no intense cyclone was observed within the Mediterranean region at any time, only a moderate system was present, and yet exceptional rainfall and flooding occurred. The emphasis of this study is on the moisture origin and transport. Moisture and energy balances are computed on different space- and time-scales, revealing that precipitation exceeds evaporation over an area inclusive of Piedmont and the northwestern Mediterranean region, on a time-scale encompassing the event and about two weeks preceding it. This is suggestive of an important moisture contribution originating from outside the region. A synoptic and dynamic analysis is then performed to outline the potential mechanisms that could have contributed to the large-scale moisture transport. The central part of the work uses a quasi-isentropic water-vapor back trajectory technique. The moisture sources obtained by this technique are compared with the results of the balances and with the synoptic situation, to unveil possible dynamic mechanisms and physical processes involved. It is found that moisture sources on a variety of atmospheric scales contribute to this event. First, an important contribution is caused by the extratropical remnants of former tropical storm Leslie. The large-scale environment related to this system allows a significant amount of moisture to be carried towards Europe. This happens on a time- scale of about 5-15 days preceding the

  17. Nitric oxide turnover in permeable river sediment

    DEFF Research Database (Denmark)

    Schreiber, Frank; Stief, Peter; Kuypers, Marcel M M


    We measured nitric oxide (NO) microprofiles in relation to oxygen (O2) and all major dissolved N-species (ammonium, nitrate, nitrite, and nitrous oxide [N2O]) in a permeable, freshwater sediment (River Weser, Germany). NO reaches peak concentrations of 0.13 μmol L-1 in the oxic zone and is consumed...... in the oxic-anoxic transition zone. Apparently, NO is produced by ammonia oxidizers under oxic conditions and consumed by denitrification under microoxic conditions. Experimental percolation of sediment cores with aerated surface water resulted in an initial rate of NO production that was 12 times higher than...

  18. Permeability of MDT chambers to water vapor

    CERN Document Server

    Palestini, S


    Tests of MDT chambers performed at the GIF facility and in the H8 test-beam area have shown relative high levels of water vapor contamination in the gas-mixture at the detector output. This effects significantly the drift properties of the MDTs. This note shows that amount of water observed is compatible with approximate estimates based on the permeability of Noryl, used in the tube end-plugs, and of EPDM, used in the O-rings of the on-chamber gas distribution.

  19. Validity of scales measuring the psychosocial determinants of HIV/STD-related risk behavior in adolescents. (United States)

    Basen-Engquist, K; Mâsse, L C; Coyle, K; Kirby, D; Parcel, G S; Banspach, S; Nodora, J


    We examined the content, construct and concurrent validity of scales to assess beliefs and self-efficacy related to adolescents' sexual risk behavior. We addressed content validity in the scale development process by drawing on literature and theory, and by pre-testing items with focus groups. We used confirmatory factor analysis of two models, an intercourse involvement model and a condom use model, to assess construct validity. The final intercourse involvement model included three scales: norms about sexual intercourse, attitudes about sexual intercourse and self-efficacy in refusing sex. The final condom use model included five scales: norms about condoms, attitudes about condom use, self-efficacy in communicating about condoms, self-efficacy in buying/using condoms and barriers to condom use. After two alterations to the models, the chi 2 and other indices indicated that the data fit the models well. Supporting the concurrent validity of the scales, high school students who had never had sexual intercourse had more negative attitudes toward sexual intercourse among teenagers, perceived norms toward sexual intercourse among teenagers to be more negative and expressed greater self-efficacy in refusing sex than did those who had experienced sexual intercourse. Consistent condom users had more positive attitudes and norms about condoms, had higher self-efficacy in communicating about and buying/using condoms, and perceived fewer barriers to condom purchase and use than did inconsistent condom users.

  20. Stability and accuracy of relative scale factor estimates for Superconducting Gravimeters (United States)

    Wziontek, H.; Cordoba, B.; Crossley, D.; Wilmes, H.; Wolf, P.; Serna, J. M.; Warburton, R.


    Superconducting gravimeters (SG) are known to be the most sensitive and most stable gravimeters. However, reliably determining the scale factor calibration and its stability with the required precision of better than 0.1% is still an open issue. The relative comparison of temporal gravity variations due to the Earths tides recorded with other calibrated gravimeters is one method to obtain the SG scale factor. Usually absolute gravimeters (AG) are used for such a comparison and the stability of the scale factor can be deduced by repeated observations over a limited period, or by comparison with precise tidal models. In recent work it was shown that spring gravimeters may not be stable enough to transfer the calibration between SG. A promising alternative is to transfer the scale factor with a well calibrated, moveable SG. To assess the perspectives of such an approach, the coherence of records from dual sphere SGs and two SGs which are being operated side by side at the stations Bad Homburg and Wettzell (Germany) and other GGP sites is analysed. To determine and remove the instrumental drift, a reference time series from the combination with AG measurements is used. The reproducibility of the scale factor and the achievable precision are investigated for comparison periods of different lenght and conclusions are drawn to the use of AG and the future application of the moveable iGrav™ SG.

  1. Short scales to assess cannabis-related problems: a review of psychometric properties

    Directory of Open Access Journals (Sweden)

    Klempova Danica


    Full Text Available Abstract Aims The purpose of this paper is to summarize the psychometric properties of four short screening scales to assess problematic forms of cannabis use: Severity of Dependence Scale (SDS, Cannabis Use Disorders Identification Test (CUDIT, Cannabis Abuse Screening Test (CAST and Problematic Use of Marijuana (PUM. Methods A systematic computer-based literature search was conducted within the databases of PubMed, PsychINFO and Addiction Abstracts. A total of 12 publications reporting measures of reliability or validity were identified: 8 concerning SDS, 2 concerning CUDIT and one concerning CAST and PUM. Studies spanned adult and adolescent samples from general and specific user populations in a number of countries worldwide. Results All screening scales tended to have moderate to high internal consistency (Cronbach's α ranging from .72 to .92. Test-retest reliability and item total correlation have been reported for SDS with acceptable results. Results of validation studies varied depending on study population and standards used for validity assessment, but generally sensitivity, specificity and predictive power are satisfactory. Standard diagnostic cut-off points that can be generalized to different populations do not exist for any scale. Conclusion Short screening scales to assess dependence and other problems related to the use of cannabis seem to be a time and cost saving opportunity to estimate overall prevalences of cannabis-related negative consequences and to identify at-risk persons prior to using more extensive diagnostic instruments. Nevertheless, further research is needed to assess the performance of the tests in different populations and in comparison to broader criteria of cannabis-related problems other than dependence.

  2. Mental Illness Related Internalized Stigma: Psychometric Properties of the Brief ISMI Scale in Greece. (United States)

    Paraskevoulakou, Alexia; Vrettou, Kassiani; Pikouli, Katerina; Triantafillou, Evgenia; Lykou, Anastasia; Economou, Marina


    Since evaluation regarding the impact of mental illness related internalized stigma is scarce, there is a great need for psychometric instruments which could contribute to understanding its adverse effects among Greek patients with severe mental illness. The Brief Internalized Stigma of Mental Illness (ISMI) scale is one of the most widely used measures designed to assess the subjective experience of stigma related to mental illness. The present study aimed to investigate the psychometric properties of the Greek version of the Brief ISMI scale. In addition to presenting psychometric findings, we explored the relationship of the Greek version of the Brief ISMI subscales with indicators of self-esteem and quality of life. 272 outpatients (108 males, 164 females) meeting the DSM-IV TR criteria for severe mental disorder (schizophrenia, bipolar disorder, major depression) completed the Brief ISMI, the RSES and the WHOQOL-BREF scales. Patients reported age and educational level. A retest was conducted with 124 patients. The Chronbach's alpha coefficient was 0 0.83. The test-retest reliability coefficients varied from 0.81 to 0.91, indicating substantial agreement. The ICC was for the total score 0.83 and for the two factors, 0.69 and 0.77 respectively. Factor analysis provided strong evidence for a two factor model. Factors 1 and 2 were named respectively "how others view me" and "how I view myself". They were negatively correlated with both RSES and WHOQOL-BREF scales, as well as with educational level. Factor 2 was significantly associated with the type of diagnosis. The Greek version of the Brief ISMI scale can be used as a reliable and valid tool for assessing mental illness related internalized stigma among Greek patients with severe mental illness.

  3. Exploring nonlinear relations: models of clinical decision making by regression with optimal scaling. (United States)

    Hartmann, Armin; Van Der Kooij, Anita J; Zeeck, Almut


    In explorative regression studies, linear models are often applied without questioning the linearity of the relations between the predictor variables and the dependent variable, or linear relations are taken as an approximation. In this study, the method of regression with optimal scaling transformations is demonstrated. This method does not require predefined nonlinear functions and results in easy-to-interpret transformations that will show the form of the relations. The method is illustrated using data from a German multicenter project on the indication criteria for inpatient or day clinic psychotherapy treatment. The indication criteria to include in the regression model were selected with the Lasso, which is a tool for predictor selection that overcomes the disadvantages of stepwise regression methods. The resulting prediction model indicates that treatment status is (approximately) linearly related to some criteria and nonlinearly related to others.

  4. Development of a scale to measure quality of visits with relatives with dementia. (United States)

    Volicer, Ladislav; DeRuvo, Laura; Hyer, Kathryn; Piechniczek-Buczek, Joanna; Riordan, Mary Ellen


    The purpose of this study was to develop a Family Visit Scale for Dementia (FAVS-D) measuring the quality of visits between nursing home residents with dementia and their family members. Scale development using a two step process based on survey data. One Veterans Administration and eleven community nursing homes. One hundred and fifteen family members visiting residents with dementia. Responses to a preliminary scale of 41 items, developed from a qualitative study, and responses to a 15 item scale, generated from the preliminary scale by eliminating items that were answered "does not apply" by a significant number of family members and by sequential iterations that removed items with low or high item total correlations or with high item-item correlations. Questionnaires were anonymously completed by family members after visit with a relative with dementia. Final FAVS-D has 14 item after eliminating 1 question that family members considered confusing. The mean score of FAVS-D was 18.7 + 6.6 (mean + SD) with a range of -10 to 28. After leaving out one outlier value, the distribution of FAVS-D score was not different from normal distribution. Reliability coefficient alpha for FAVS-D was 0.77. The factor analysis produced 4 factors: factor 1 (7 items, ? = .82) related to nursing staff interaction with residents and visitors, factor 2 (4 items, ? = .73) related to meaningfulness of the visit, factor 3 (2 items, ? = .85) related to cleanliness and factor 4 (1 item) related to the connection established between the visitor and the resident. There was a significant difference between total FAVS-D scores of two facilities that provided most of the questionnaires. Subscores for nursing staff and meaningfulness factors in these two facilities were also significantly different, while subscores for cleanliness and connection were similar. This study indicates that it is possible to measure family visit satisfaction. The most important factors of FAVS-D, are factor 1 related to

  5. The kinetics of denitrification in permeable sediments

    DEFF Research Database (Denmark)

    Evrard, Victor; Glud, Ronnie N.; Cook, Perran L. M.


    Permeable sediments comprise the majority of shelf sediments, yet the rates of denitrification remain highly uncertain in these environments. Computational models are increasingly being used to understand the dynamics of denitrification in permeable sediments, which are complex environments to st...

  6. Permeable Pavement Research - Edison, New Jersey (United States)

    This presentation provides the background and summary of results collected at the permeable pavement parking lot monitored at the EPA facility in Edison, NJ. This parking lot is surfaced with permeable interlocking concrete pavers (PICP), pervious concrete, and porous asphalt. ...

  7. Relative importance of habitat and landscape scales on butterfly communities of urbanizing areas. (United States)

    Lizée, Marie-Hélène; Bonardo, Rémi; Mauffrey, Jean-François; Bertaudière-Montes, Valérie; Tatoni, Thierry; Deschamps-Cottin, Magali


    Agricultural decline and urbanization entail rapid alterations of the patterns of organization of rural landscapes in Europe. The spread of the urban footprint to the adjacent countryside contributes to the development of new anthropogenic ecosystems in formerly rural hinterlands. In this study, butterflies are considered as biological indicators of these rapid environmental changes. Our purpose is to better understand changes in biodiversity related to the evolution of available habitats in a mutating landscape. In this study, we investigate butterfly communities of four land-use types (fallow lands, gardens, vineyards, woodlands) within different landscape contexts. Our results reveal that variations in structure and functional composition of these communities are related to different levels of human disturbance at both landscape scale and habitat scale. Copyright © 2010 Académie des sciences. Published by Elsevier SAS. All rights reserved.

  8. Single-field consistency relations of large scale structure part III: test of the equivalence principle

    Energy Technology Data Exchange (ETDEWEB)

    Creminelli, Paolo [Abdus Salam International Centre for Theoretical Physics, Strada Costiera 11, Trieste, 34151 (Italy); Gleyzes, Jérôme; Vernizzi, Filippo [CEA, Institut de Physique Théorique, Gif-sur-Yvette cédex, F-91191 France (France); Hui, Lam [Physics Department and Institute for Strings, Cosmology and Astroparticle Physics, Columbia University, New York, NY, 10027 (United States); Simonović, Marko, E-mail:, E-mail:, E-mail:, E-mail:, E-mail: [SISSA, via Bonomea 265, Trieste, 34136 (Italy)


    The recently derived consistency relations for Large Scale Structure do not hold if the Equivalence Principle (EP) is violated. We show it explicitly in a toy model with two fluids, one of which is coupled to a fifth force. We explore the constraints that galaxy surveys can set on EP violation looking at the squeezed limit of the 3-point function involving two populations of objects. We find that one can explore EP violations of order 10{sup −3}÷10{sup −4} on cosmological scales. Chameleon models are already very constrained by the requirement of screening within the Solar System and only a very tiny region of the parameter space can be explored with this method. We show that no violation of the consistency relations is expected in Galileon models.

  9. [Scale Relativity Theory in living beings morphogenesis: fratal, determinism and chance]. (United States)

    Chaline, J


    The Scale Relativity Theory has many biological applications from linear to non-linear and, from classical mechanics to quantum mechanics. Self-similar laws have been used as model for the description of a huge number of biological systems. Theses laws may explain the origin of basal life structures. Log-periodic behaviors of acceleration or deceleration can be applied to branching macroevolution, to the time sequences of major evolutionary leaps. The existence of such a law does not mean that the role of chance in evolution is reduced, but instead that randomness and contingency may occur within a framework which may itself be structured in a partly statistical way. The scale relativity theory can open new perspectives in evolution. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  10. Scaling relations for forced oscillators in the transition from a dissipative to a Hamiltonian system

    DEFF Research Database (Denmark)

    Flensberg, Karsten; Svensmark, Henrik


    The dynamics and the stability of a forced damped nonlinear oscillator driven at twice its resonance frequency is studied. At the transition from a dissipative system to a Hamiltonian system, simple scalings relations are found by the use of the Floquet theory of the linearized problem. The Floqu...... exponents and the period-doubling bifurcation point are determined analytically in the limit of small damping. The theory is compared to numerical calculations on a Duffing oscillator and excellent agreement is found....

  11. The Debye light scattering equation’s scaling relation reveals the purity of synthetic dendrimers

    Energy Technology Data Exchange (ETDEWEB)

    Tseng, Hui-Yu; Chen, Hsiao-Ping [National Chung Cheng University, Department of Chemistry and Biochemistry (China); Tang, Yi-Hsuan [Kaohsiung Medical University, Department of Medicinal and Applied Chemistry (China); Chen, Hui-Ting [Kaohsiung Medical University, Department of Fragrance and Cosmetic Science (China); Kao, Chai-Lin, E-mail: [Kaohsiung Medical University, Department of Medicinal and Applied Chemistry (China); Wang, Shau-Chun, E-mail: [National Chung Cheng University, Department of Chemistry and Biochemistry (China)


    Spherical dendrimer structures cannot be structurally modeled using conventional polymer models of random coil or rod-like configurations during the calibration of the static light scattering (LS) detectors used to determine the molecular weight (M.W.) of a dendrimer or directly assess the purity of a synthetic compound. In this paper, we used the Debye equation-based scaling relation, which predicts that the static LS intensity per unit concentration is linearly proportional to the M.W. of a synthetic dendrimer in a dilute solution, as a tool to examine the purity of high-generational compounds and to monitor the progress of dendrimer preparations. Without using expensive equipment, such as nuclear magnetic resonance or mass spectrometry, this method only required an affordable flow injection set-up with an LS detector. Solutions of the purified dendrimers, including the poly(amidoamine) (PAMAM) dendrimer and its fourth to seventh generation pyridine derivatives with size range of 5–9 nm, were used to establish the scaling relation with high linearity. The use of artificially impure mixtures of six or seven generations revealed significant deviations from linearity. The raw synthesized products of the pyridine-modified PAMAM dendrimer, which included incompletely reacted dendrimers, were also examined to gauge the reaction progress. As a reaction toward a particular generational derivative of the PAMAM dendrimers proceeded over time, deviations from the linear scaling relation decreased. The difference between the polydispersity index of the incompletely converted products and that of the pure compounds was only about 0.01. The use of the Debye equation-based scaling relation, therefore, is much more useful than the polydispersity index for monitoring conversion processes toward an indicated functionality number in a given preparation.Graphical abstract.

  12. A weak lensing detection of a deviation from General Relativity on cosmic scales


    Bean, Rachel


    We consider evidence for deviations from General Relativity (GR) in the growth of large scale structure, using two parameters, $\\gamma$ and $\\eta$, to quantify the modification. We consider the Integrated Sachs-Wolfe effect (ISW) in the WMAP Cosmic Microwave Background data, the cross-correlation between the ISW and galaxy distributions from 2MASS and SDSS surveys, and the weak lensing shear field from the Hubble Space Telescope's COSMOS survey along with measurements of the cosmic expansion ...

  13. The Debye light scattering equation's scaling relation reveals the purity of synthetic dendrimers (United States)

    Tseng, Hui-Yu; Chen, Hsiao-Ping; Tang, Yi-Hsuan; Chen, Hui-Ting; Kao, Chai-Lin; Wang, Shau-Chun


    Spherical dendrimer structures cannot be structurally modeled using conventional polymer models of random coil or rod-like configurations during the calibration of the static light scattering (LS) detectors used to determine the molecular weight (M.W.) of a dendrimer or directly assess the purity of a synthetic compound. In this paper, we used the Debye equation-based scaling relation, which predicts that the static LS intensity per unit concentration is linearly proportional to the M.W. of a synthetic dendrimer in a dilute solution, as a tool to examine the purity of high-generational compounds and to monitor the progress of dendrimer preparations. Without using expensive equipment, such as nuclear magnetic resonance or mass spectrometry, this method only required an affordable flow injection set-up with an LS detector. Solutions of the purified dendrimers, including the poly(amidoamine) (PAMAM) dendrimer and its fourth to seventh generation pyridine derivatives with size range of 5-9 nm, were used to establish the scaling relation with high linearity. The use of artificially impure mixtures of six or seven generations revealed significant deviations from linearity. The raw synthesized products of the pyridine-modified PAMAM dendrimer, which included incompletely reacted dendrimers, were also examined to gauge the reaction progress. As a reaction toward a particular generational derivative of the PAMAM dendrimers proceeded over time, deviations from the linear scaling relation decreased. The difference between the polydispersity index of the incompletely converted products and that of the pure compounds was only about 0.01. The use of the Debye equation-based scaling relation, therefore, is much more useful than the polydispersity index for monitoring conversion processes toward an indicated functionality number in a given preparation.

  14. Free energy of cluster formation and a new scaling relation for the nucleation rate. (United States)

    Tanaka, Kyoko K; Diemand, Jürg; Angélil, Raymond; Tanaka, Hidekazu


    Recent very large molecular dynamics simulations of homogeneous nucleation with (1 - 8) × 10(9) Lennard-Jones atoms [J. Diemand, R. Angélil, K. K. Tanaka, and H. Tanaka, J. Chem. Phys. 139, 074309 (2013)] allow us to accurately determine the formation free energy of clusters over a wide range of cluster sizes. This is now possible because such large simulations allow for very precise measurements of the cluster size distribution in the steady state nucleation regime. The peaks of the free energy curves give critical cluster sizes, which agree well with independent estimates based on the nucleation theorem. Using these results, we derive an analytical formula and a new scaling relation for nucleation rates: ln J'/η is scaled by ln S/η, where the supersaturation ratio is S, η is the dimensionless surface energy, and J(') is a dimensionless nucleation rate. This relation can be derived using the free energy of cluster formation at equilibrium which corresponds to the surface energy required to form the vapor-liquid interface. At low temperatures (below the triple point), we find that the surface energy divided by that of the classical nucleation theory does not depend on temperature, which leads to the scaling relation and implies a constant, positive Tolman length equal to half of the mean inter-particle separation in the liquid phase.

  15. Confirmation of general relativity on large scales from weak lensing and galaxy velocities. (United States)

    Reyes, Reinabelle; Mandelbaum, Rachel; Seljak, Uros; Baldauf, Tobias; Gunn, James E; Lombriser, Lucas; Smith, Robert E


    Although general relativity underlies modern cosmology, its applicability on cosmological length scales has yet to be stringently tested. Such a test has recently been proposed, using a quantity, E(G), that combines measures of large-scale gravitational lensing, galaxy clustering and structure growth rate. The combination is insensitive to 'galaxy bias' (the difference between the clustering of visible galaxies and invisible dark matter) and is thus robust to the uncertainty in this parameter. Modified theories of gravity generally predict values of E(G) different from the general relativistic prediction because, in these theories, the 'gravitational slip' (the difference between the two potentials that describe perturbations in the gravitational metric) is non-zero, which leads to changes in the growth of structure and the strength of the gravitational lensing effect. Here we report that E(G) = 0.39 +/- 0.06 on length scales of tens of megaparsecs, in agreement with the general relativistic prediction of E(G) approximately 0.4. The measured value excludes a model within the tensor-vector-scalar gravity theory, which modifies both Newtonian and Einstein gravity. However, the relatively large uncertainty still permits models within f(R) theory, which is an extension of general relativity. A fivefold decrease in uncertainty is needed to rule out these models.

  16. Evolution of Cluster Scaling Relations with Near-infrared and Spitzer Imaging (United States)

    Svoboda, Brian E.; Arnold, R. L.; Welch, T. J.; Rines, K.; Finn, R. A.; Vikhlinin, A.


    We present scaling relations for a unique sample of 41 X-ray-selected clusters at moderate redshift (z = 0.35 -- 0.90). Chandra data of the clusters have been used to constrain dark energy (the Chandra Cluster Cosmology Project). We have deep Flamingos/ISPI Ks-band imaging from the NOAO 4m telescopes and mid-infrared IRAC imaging from Spitzer for all 41 clusters. We use these data to estimate the cluster richnesses and stellar masses. We compare these infrared properities to X-ray properties (TX, YX, M500) from Chandra data to measure the evolution of cluster scaling relations and the halo occupation function. Both semi-analytic models and simulations incorporating radiative cooling and galaxy formation overpredict the stellar masses of clusters by a factor of 2-3. Our data will help constrain models of galaxy formation and evolution in clusters. The evolution of cluster scaling relations is an important input for understanding cosmological constraints from future cluster surveys. Companion posters study the evolution of luminosity functions and star formation in these clusters.

  17. Relations Between Coastal Catchment Attributes and Submarine Groundwater Discharge at Different Scales (United States)

    Moosdorf, N.; Langlotz, S. T.


    Submarine groundwater discharge (SGD) has been recognized as a relevant field of coastal research in the last years. Its implications on local scale have been documented by an increasing number of studies researching individual locations with SGD. The local studies also often emphasize its large variability. On the other end, global scale studies try to estimate SGD related fluxes of e.g. carbon (Cole et al., 2007) and nitrogen (Beusen et al., 2013). These studies naturally use a coarse resolution, too coarse to represent the aforementioned local variability of SGD (Moosdorf et al., 2015). A way to transfer information of the local variability of SGD to large scale flux estimates is needed. Here we discuss the upscaling of local studies based on the definition and typology of coastal catchments. Coastal catchments are those stretches of coast that do not drain into major rivers but directly into the sea. Their attributes, e.g. climate, topography, land cover, or lithology can be used to extrapolate from the local scale to larger scales. We present first results of a typology, compare coastal catchment attributes to SGD estimates from field studies and discuss upscaling as well as the associated uncertainties. This study aims at bridging the gap between the scales and enabling an improved representation of local scale variability on continental to global scale. With this, it can contribute to a recent initiative to model large scale SGD fluxes (NExT SGD). References: Beusen, A.H.W., Slomp, C.P., Bouwman, A.F., 2013. Global land-ocean linkage: direct inputs of nitrogen to coastal waters via submarine groundwater discharge. Environmental Research Letters, 8(3): 6. Cole, J.J., Prairie, Y.T., Caraco, N.F., McDowell, W.H., Tranvik, L.J., Striegl, R.G., Duarte, C.M., Kortelainen, P., Downing, J.A., Middelburg, J.J., Melack, J., 2007. Plumbing the global carbon cycle: Integrating inland waters into the terrestrial carbon budget. Ecosystems, 10(1): 171-184. Moosdorf, N

  18. Cosmological special relativity the large scale structure of space, time and velocity

    CERN Document Server

    Carmeli, Moshe


    This book presents Einstein's theory of space and time in detail, and describes the large-scale structure of space, time and velocity as a new cosmological special relativity. A cosmological Lorentz-like transformation, which relates events at different cosmic times, is derived and applied. A new law of addition of cosmic times is obtained, and the inflation of the space at the early universe is derived, both from the cosmological transformation. The relationship between cosmic velocity, acceleration and distances is given. In the appendices gravitation is added in the form of a cosmological g

  19. Gravitation and Special Relativity from Compton Wave Interactions at the Planck Scale: An Algorithmic Approach (United States)

    Blackwell, William C., Jr.


    In this paper space is modeled as a lattice of Compton wave oscillators (CWOs) of near- Planck size. It is shown that gravitation and special relativity emerge from the interaction between particles Compton waves. To develop this CWO model an algorithmic approach was taken, incorporating simple rules of interaction at the Planck-scale developed using well known physical laws. This technique naturally leads to Newton s law of gravitation and a new form of doubly special relativity. The model is in apparent agreement with the holographic principle, and it predicts a cutoff energy for ultrahigh-energy cosmic rays that is consistent with observational data.

  20. Variability of permeability with diameter of conduit

    Indian Academy of Sciences (India)

    ... creating a permeability profile similar to the velocity profile. An equation was obtained to establish this. We also found that peak values of permeability increase with increasing porosity, and therefore entry length increases with increasing porosity with all other parameters kept constant. A plot of peak permeability versus ...

  1. Latent structure of the social anxiety scale and relations between social anxiety and irrational beliefs

    Directory of Open Access Journals (Sweden)

    Tovilović Snežana


    Full Text Available The research which was realized belongs to one of three research fields within framework of rational-emotional-behavioral therapy (REBT - to the theory of emotional disorders. It was undertaken with the aim to establish presence and nature of relations between social anxiety, treated as dimension and the construct of irrational beliefs from REBT theory. The research was carried out on the sample of 261 students of Novi Sad University, both genders, age 18 to 26. First of all, the latent structure of newly constructed Scale of Social Anxiety (SA of the author Tovilović S. was tested. SA scale was proved to be of satisfying reliability (α =0.92. Principal-component factor analysis was conducted under gathered data. Four factors of social anxiety, which explain 44,09% of total variance of the items of SA scale, were named: social-evaluation anxiety, inhibition in social-uncertain situations, low self-respect and hypersensitivity on rejection. The other test that was used is Scale of General Attitudes and Beliefs of the author Marić Z. Reliability of the sub-scale of irrational beliefs that was got on our sample is α =0.91 yet the subscale of rational beliefs is α =0.70. Canonical correlational analysis was conducted under manifest variables of both scales. Three pairs of statistically significant canonical factors were got, with correlations within the span between Rc=0.78 and Rc=0.64. We discussed nature of correlation between social anxiety and irrational beliefs in the light of REBT model of social phobia, REBT theory of emotional disorder, researches and model of social anxiety in wider, cognitive-behavioral framework.

  2. Allometric Relations and Scaling Laws for the Cardiovascular System of Mammals

    Directory of Open Access Journals (Sweden)

    Thomas H. Dawson


    Full Text Available The modeling of the cardiovascular system of mammals is discussed within the framework of governing allometric relations and related scaling laws for mammals. An earlier theory of the writer for resting-state cardiovascular function is reviewed and standard solutions discussed for reciprocal quarter-power relations for heart rate and cardiac output per unit body mass. Variation in the basic cardiac process controlling heart beat is considered and shown to allow alternate governing relations. Results have potential application in explaining deviations from the noted quarter-power relations. The work thus indicates that the cardiovascular systems of all mammals are designed according to the same general theory and, accordingly, that it provides a quantitative means to extrapolate measurements of cardiovascular form and function from small mammals to the human. Various illustrations are included. Work described here also indicates that the basic scaling laws from the theory apply to children and adults, with important applications such as the extrapolation of therapeutic drug dosage requirements from adults to children.

  3. Modeling flow in porous media with double porosity/permeability: Mathematical model, properties, and analytical solutions

    CERN Document Server

    Nakshatrala, K B; Ballarini, R


    Geo-materials such as vuggy carbonates are known to exhibit multiple spatial scales. A common manifestation of spatial scales is the presence of (at least) two different scales of pores, which is commonly referred to as double porosity. To complicate things, the pore-network at each scale exhibits different permeability, and these networks are connected through fissure and conduits. Although some models are available in the literature, they lack a strong theoretical basis. This paper aims to fill this lacuna by providing the much needed theoretical foundations of the flow in porous media which exhibit double porosity/permeability. We first obtain a mathematical model for double porosity/permeability using the maximization of rate of dissipation hypothesis, and thereby providing a firm thermodynamic underpinning. We then present, along with mathematical proofs, several important mathematical properties that the solutions to the double porosity/permeability model satisfy. These properties are important in their...

  4. Disk galaxy scaling relations at intermediate redshifts. I. The Tully-Fisher and velocity-size relations (United States)

    Böhm, Asmus; Ziegler, Bodo L.


    Aims: Galaxy scaling relations such as the Tully-Fisher relation (between the maximum rotation velocity Vmax and luminosity) and the velocity-size relation (between Vmax and the disk scale length) are powerful tools to quantify the evolution of disk galaxies with cosmic time. Methods: We took spatially resolved slit spectra of 261 field disk galaxies at redshifts up to z ≈ 1 using the FORS instruments of the ESO Very Large Telescope. The targets were selected from the FORS Deep Field and William Herschel Deep Field. Our spectroscopy was complemented with HST/ACS imaging in the F814W filter. We analyzed the ionized gas kinematics by extracting rotation curves from the two-dimensional spectra. Taking into account all geometrical, observational, and instrumental effects, these rotation curves were used to derive the intrinsic Vmax. Results: Neglecting galaxies with disturbed kinematics or insufficient spatial rotation curve extent, Vmax was reliably determined for 124 galaxies covering redshifts 0.05 < z < 0.97. This is one of the largest kinematic samples of distant disk galaxies to date. We compared this data set to the local B-band Tully-Fisher relation and the local velocity-size relation. The scatter in both scaling relations is a factor of ~2 larger at z ≈ 0.5 than at z ≈ 0. The deviations of individual distant galaxies from the local Tully-Fisher relation are systematic in the sense that the galaxies are increasingly overluminous toward higher redshifts, corresponding to an overluminosity ΔMB = -(1.2 ± 0.5) mag at z = 1. This luminosity evolution at given Vmax is probably driven by younger stellar populations of distant galaxies with respect to their local counterparts, potentially combined with modest changes in dark matter mass fractions. The analysis of the velocity-size relation reveals that disk galaxies of a given Vmax have grown in size by a factor of ~1.5 over the past ~8 Gyr, most likely through accretion of cold gas and/or small satellites

  5. Hydraulic Permeability of Resorcinol-Formaldehyde Resin

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Paul Allen [ORNL


    An ion exchange process using spherical resorcinol-formaldehyde (RF) resin is the baseline process for removing cesium from the dissolved salt solution in the high-level waste tanks at the Hanford Site, using large scale columns as part of the Waste Treatment Plant (WTP). The RF resin is also being evaluated for use in the proposed small column ion exchange (SCIX) system, which is an alternative treatment option at Hanford and at the Savannah River Site (SRS). A recirculating test loop with a small ion exchange column was used to measure the effect of oxygen uptake and radiation exposure on the permeability of a packed bed of the RF resin. The lab-scale column was designed to be prototypic of the proposed Hanford columns at the WTP. Although the test equipment was designed to model the Hanford ion exchange columns, the data on changes in the hydraulic permeability of the resin will also be valuable for determining potential pressure drops through the proposed SCIX system. The superficial fluid velocity in the lab-scale test (3.4-5.7 cm/s) was much higher than is planned for the full-scale Hanford columns to generate the maximum pressure drop expected in those columns (9.7 psig). The frictional drag from this high velocity produced forces on the resin in the lab-scale tests that matched the design basis of the full-scale Hanford column. Any changes in the resin caused by the radiation exposure and oxygen uptake were monitored by measuring the pressure drop through the lab-scale column and the physical properties of the resin. Three hydraulic test runs were completed, the first using fresh RF resin at 25 C, the second using irradiated resin at 25 C, and the third using irradiated resin at 45 C. A Hanford AP-101 simulant solution was recirculated through a test column containing 500 mL of Na-form RF resin. Known amounts of oxygen were introduced into the primary recirculation loop by saturating measured volumes of the simulant solution with oxygen and reintroducing

  6. Scaling Relations of Lognormal Type Growth Process with an Extremal Principle of Entropy

    Directory of Open Access Journals (Sweden)

    Zi-Niu Wu


    Full Text Available The scale, inflexion point and maximum point are important scaling parameters for studying growth phenomena with a size following the lognormal function. The width of the size function and its entropy depend on the scale parameter (or the standard deviation and measure the relative importance of production and dissipation involved in the growth process. The Shannon entropy increases monotonically with the scale parameter, but the slope has a minimum at p 6/6. This value has been used previously to study spreading of spray and epidemical cases. In this paper, this approach of minimizing this entropy slope is discussed in a broader sense and applied to obtain the relationship between the inflexion point and maximum point. It is shown that this relationship is determined by the base of natural logarithm e ' 2.718 and exhibits some geometrical similarity to the minimal surface energy principle. The known data from a number of problems, including the swirling rate of the bathtub vortex, more data of droplet splashing, population growth, distribution of strokes in Chinese language characters and velocity profile of a turbulent jet, are used to assess to what extent the approach of minimizing the entropy slope can be regarded as useful.

  7. Schooling behaviour and environmental forcing in relation to anchoveta distribution: An analysis across multiple spatial scales (United States)

    Bertrand, Arnaud; Gerlotto, François; Bertrand, Sophie; Gutiérrez, Mariano; Alza, Luis; Chipollini, Andres; Díaz, Erich; Espinoza, Pepe; Ledesma, Jesús; Quesquén, Roberto; Peraltilla, Salvador; Chavez, Francisco


    The Peruvian anchovy or anchoveta ( Engraulis ringens) supports the highest worldwide fishery landings and varies in space and time over many scales. Here we present the first comprehensive sub-mesocale study of anchoveta distribution in relation to the environment. During November 2004, we conducted a behavioural ecology survey off central Peru and used a series of observational and sampling tools including SST and CO 2 sensors, Niskin bottles, CTD probes, zooplankton sampling, stomach content analysis, echo-sounder, multibeam sonar, and bird observations. The sub-mesoscale survey areas were chosen from mesoscale acoustic surveys. A routine coast-wide (∼2000 km) acoustic survey performed just after the sub-mesoscale surveys, provided information at an even larger population scale. The availability of nearly concurrent sub-mesoscale, mesoscale and coast-wide information on anchoveta distribution allowed for a unique multi-scale synthesis. At the sub-mesoscale (100s m to km) physical processes (internal waves and frontogenesis) concentrated plankton into patches and determined anchoveta spatial distribution. At the mesoscale (10s km) location relative to the zone of active upwelling (and age of the upwelled water) and the depth of the oxycline had strong impacts on the anchoveta. Finally, over 100s km the size of the productive area, as defined by the upwelled cold coastal waters, was the determining factor. We propose a conceptual view of the relative importance of social behaviour and environmental (biotic and abiotic) processes on the spatial distribution of anchoveta. Our ecological space has two y-axis; one based on self-organization (social behaviour), and the other based on the environmental processes. At scales from the individual (10s cm), to the nucleus (m), social behaviour (e.g. the need to school) drives spatial organization. At scales larger than the school, environmental forces are the main driver of fish distribution. The conceptual ecosystem

  8. Modeling of Multiphase with Respect to Low Interfacial Tension by Pseudo-Two-Phase Relative Permeability Functions Modélisation d'un écoulement polyphasique à faible tension interfaciale par des fonctions pseudo-biphasiques de perméabilité relative

    Directory of Open Access Journals (Sweden)

    Pusch G.


    Full Text Available A new 2-parameter desaturation function is introduced which offers a broader range of applicability to reservoir rock. Based on this function two-phase relative permeabilities are derived for oil phase and microemulsion flow. These functions are used to match a laboratory experiment by using surfactant flooding for a single surfactant system. Les auteurs présentent une nouvelle fonction de désaturation à deux paramètres qui offre une plus large gamme de possibilités d'application aux roches réservoir. On tire de cette fonction des perméabilités relatives biphasiques pour l'écoulement de la phase pétrole et d'une microémulsion. Ces fonctions sont utilisées pour reproduire une expérience de laboratoire avec injection de surfactant pour un seul système surfactant.

  9. Influence du contraste de viscosités sur les perméabilités relatives lors du drainage. Expérimentation et modélisation Influence of Viscosity Ratio on Relative Permeabilities During Drainage. Experimenting and Modeling.

    Directory of Open Access Journals (Sweden)

    Danis M.


    Full Text Available Des expériences menées à l'Institut Français du Pétrole, sur des échantillons de milieu poreux saturés en eau résiduelle, montrent que la perméabilité relative à l'huile peut dépendre, dans certaines conditions décrites dans cet article, de la viscosité de l'huile. Ces expériences ont été à l'origine d'une modélisation numérique réalisée au laboratoire Énergétique et Phénomènes de Transferts (Bordeaux. Dans cette modélisation, le milieu poreux est représenté comme un faisceau de conduits périodiques parallèles, semblables mais de dimension répartie selon une loi sensiblement gaussienne. Moyennant certaines hypothèses, on peut obtenir les courbes donnant les perméabilités relatives en fonction de la saturation réduite en huile, pour différentes viscosités de l'huile. Les résultats numériques et expérimentaux sont alors confrontés. Les conclusions principales sont les suivantes : - la perméabilité relative à l'huile peut dépendre de la viscosité de l'huile, et être supérieure à l'unité ; - l'influence de la viscosité sur la perméabilité relative à l'huile semble d'autant plus forte que le milieu poreux est plus complexe. At the Institut Français du Pétrole, experiments on porous-media samples saturated with residual water showed that oil relative permeability may depend on oil viscosity under various conditions described in this article. A numerical model representing these experiments was created at the Laboratoire Energétique et Phénomènes de Transferts in Bordeaux. The porous medium used for this modeling is represented by a bundle of parallel periodic stream-lines having sizes distributed according ta a more-or-less Gaussian law. By taking various hypotheses into account, curves may be obtained which give relative permeabilities according to reduced oil saturation for different oil viscosities. Numerical and experimental results are then compared. The main conclusions are: (i relative

  10. Top-spray fluid bed coating: Scale-up in terms of relative droplet size and drying force

    DEFF Research Database (Denmark)

    Hede, Peter Dybdahl; Bach, P.; Jensen, Anker Degn


    Top-spray fluid bed coating scale-up experiments have been performed in three scales in order to test the validity of two parameters as possible scaling parameters: The drying force and the relative droplet size. The aim was to be able to reproduce the degree of agglomeration as well as the mecha......Top-spray fluid bed coating scale-up experiments have been performed in three scales in order to test the validity of two parameters as possible scaling parameters: The drying force and the relative droplet size. The aim was to be able to reproduce the degree of agglomeration as well...... as binder. Coating experiments were repeated for various drying force and relative droplet size values in three top-spray fluid bed scales being a small-scale (Type: GEA Aeromatic-Fielder Strea-1), medium-scale (Type: Niro MP-1) and large-scale (Type: GEA MP-2/3). The tendency of agglomeration was assessed...... in terms of particle size fractions larger than 425 mu m determined by sieve analysis. Results indicated that the particle size distribution may be reproduced across scale with statistical valid precision by keeping the drying force and the relative droplet size constant across scale. It is also shown...

  11. Coulometric-potentiometric determination of autoprotolysis constant and relative acidity scale of water

    Directory of Open Access Journals (Sweden)

    Džudović Radmila M.


    Full Text Available The autoprotolysis constant and relative acidity scale of water were determined by applying the coulometric-potentiometric method and a hydrogen/palladium (H2/Pd generator anode. In the described procedure for the evaluation of autoprotolysis constant, a strong base generated coulometrically at the platinum cathode in situ in the electrolytic cell, in presence of sodium perchlorate as the supporting electrolyte, is titrated with hydrogen ions obtained by the anodic oxidation of hydrogen dissolved in palladium electrode. The titration was carried out with a glass-SCE electrode pair at 25.0±0.1°C. The value obtained pKw = 13.91 ± 0.06 is in agreement with literature data. The range of acidity scale of water is determined from the difference between the halfneutralization potentials of electrogenerated perchloric acid and that of sodium hydroxide in a sodium perchlorate medium. The halfneutralization potentials were measured using both a glass-SCE and a (H2/Pdind-SCE electrode pairs. A wider range of relative acidity scale of water was obtained with the glass-SCE electrode pair.

  12. Scaling relations for galaxies of all types with CALIFA and MaNGA surveys. (United States)

    Aquino-Ortíz, E.; Sánchez-Sánchez, S. F.; Valenzuela, O.; Cano-Díaz, M.; Hernández-Toledo, H.


    We used gas and stellar kinematics for the final Data Release of 667 spatially resolved galaxies publicly available from Calar Alto Legacy Integral Field Area survey (CALIFA) with the aim of study dynamical scaling relations as Tully & Fisher for rotation velocity, Faber & Jackson for velocity dispersion and also a combination of them through the S_{K} parameter defined as S_{K}^2 = KV_{rot}^2 + σ^2. We found a offset between gas and stellar kinematics in Tully & Fisher and Faber & Jackson relations, however when we used the S_{K} parameter all galaxies regardless of the morphological type lie in this M_{*} vs S_{k} scaling relation with a significant improvement compared with the M_{*} vs V_{rot} and M_{*} vs σ relations, in agreement with previous studies with SAMI survey, however the slope ant zero-point are different with them. We also explored different values of the K parameter, as well as different proxys to estimate V_{rot} in order to understand and characterize the physical source of scatter, slope and zero-point.

  13. Multidimensional body-self relations questionnaire-appearance scales: psychometric properties of the Greek version. (United States)

    Argyrides, Marios; Kkeli, Natalie


    The psychometric properties of a Greek version of the Multidimensional Body-Self Relations Questionnaire-Appearance Scales (MBSRQ-AS) were studied. A total of 1,312 high school students (463 boys, 849 girls) were administered the Greek MBSRQ-AS, the Greek Appearance Schemas Inventory-Revised (ASI-R) and the Greek Sociocultural Attitudes Towards Appearance Questionnaire-3 (SATAQ-3). An exploratory factor analysis revealed that the Greek MBSRQ-AS items significantly loaded with the scale's main factors. Internal consistencies of the subscales ranged from .76 to .86. Test-retest reliabilities ranged from .75 to .93. Convergent validity was also confirmed as the Greek MBSRQ-AS subscales correlated positively with the ASI-R and the SATAQ-3.

  14. Effect of aggregate grain size distribution on properties of permeable ...

    African Journals Online (AJOL)

    ) ratio on the mechanical properties of permeable concrete is investigated. The aim of this study is to prepare permeable concrete mixture with optimum properties in terms of strength and permeability. For this purpose, five different permeable ...

  15. Developing Interest in Art Scale and Determining the Relation between Personality Type of Teacher Candidates and Their Interest in Art (United States)

    Taskesen, Orhan


    The goal of this study is to develop a scale that measures individuals' interest in art and to test if there is a relation between this scale and personality types. For this aim, in the first stage of the study, a scale that can measure university students' interest in art is developed. Draft scale, which is made of 25 items, is conducted on 171…

  16. Scale relativity theory and integrative systems biology: 2. Macroscopic quantum-type mechanics. (United States)

    Nottale, Laurent; Auffray, Charles


    In these two companion papers, we provide an overview and a brief history of the multiple roots, current developments and recent advances of integrative systems biology and identify multiscale integration as its grand challenge. Then we introduce the fundamental principles and the successive steps that have been followed in the construction of the scale relativity theory, which aims at describing the effects of a non-differentiable and fractal (i.e., explicitly scale dependent) geometry of space-time. The first paper of this series was devoted, in this new framework, to the construction from first principles of scale laws of increasing complexity, and to the discussion of some tentative applications of these laws to biological systems. In this second review and perspective paper, we describe the effects induced by the internal fractal structures of trajectories on motion in standard space. Their main consequence is the transformation of classical dynamics into a generalized, quantum-like self-organized dynamics. A Schrödinger-type equation is derived as an integral of the geodesic equation in a fractal space. We then indicate how gauge fields can be constructed from a geometric re-interpretation of gauge transformations as scale transformations in fractal space-time. Finally, we introduce a new tentative development of the theory, in which quantum laws would hold also in scale space, introducing complexergy as a measure of organizational complexity. Initial possible applications of this extended framework to the processes of morphogenesis and the emergence of prokaryotic and eukaryotic cellular structures are discussed. Having founded elements of the evolutionary, developmental, biochemical and cellular theories on the first principles of scale relativity theory, we introduce proposals for the construction of an integrative theory of life and for the design and implementation of novel macroscopic quantum-type experiments and devices, and discuss their potential

  17. The Physical Conditions and Scaling Relations of Multi-Phase Galactic Outflows (United States)

    Chisholm, John


    Star formation injects energy and momentum into the interstellar medium, accelerating the gas outward in a galaxy-scale outflow. These outflows eject large amounts of gas out of star-forming regions, helping to control the number of stars formed in a galaxy. In this thesis, I present new observational studies of galactic outflows in the local universe that describe the physical conditions of outflows and how the physical conditions scale with host galaxy properties. I find shallow, yet statistically significant, scaling relations between the outflow velocity and both the star formation rate and the stellar mass of their host galaxies. These scaling relations describe the acceleration of gas out of galaxies, and provide constraints for galaxy evolution models. In particular, I find that low-mass galaxies (stellar mass less than 1010.5 M[special character omitted]) generate low-ionization outflows faster than their escape velocities, while high-mass galaxies generally do not, unless they are merging with another galaxy. I then explore a variety of ionic transitions that probe the different ionization stages of the outflow. The outflow velocity of each transition depends on the strength of the transition, and I model the outflows as a single co-moving phase. Photo-ionization models determine the ionization structure and metallicities of the outflows. For the local merger NGC 6090, I combine these ionization models with detailed fits to the optical depth and covering fraction of the Si IV absorption lines. These fits determine how the velocity, density, covering fraction and mass outflow rate scales with distance from the starburst. Finally, I study the molecular outflow of M 82 using three different CO emission lines. I model the temperature and density of the molecular gas to estimate the total molecular mass outflow rate, without relying on uncertain conversion factors. I compare the mass outflow rate to the star formation rate and an estimate of the inflow rate to

  18. On the permeability of fractal tube bundles

    CERN Document Server

    Zinovik, I


    The permeability of a porous medium is strongly affected by its local geometry and connectivity, the size distribution of the solid inclusions and the pores available for flow. Since direct measurements of the permeability are time consuming and require experiments that are not always possible, the reliable theoretical assessment of the permeability based on the medium structural characteristics alone is of importance. When the porosity approaches unity, the permeability-porosity relationships represented by the Kozeny-Carman equations and Archie's law predict that permeability tends to infinity and thus they yield unrealistic results if specific area of the porous media does not tend to zero. The goal of this paper is an evaluation of the relationships between porosity and permeability for a set of fractal models with porosity approaching unity and a finite permeability. It is shown that the two-dimensional foams generated by finite iterations of the corresponding geometric fractals can be used to model poro...

  19. Free convective controls on sequestration of salts into low-permeability strata: insights from sand tank laboratory experiments and numerical modelling

    NARCIS (Netherlands)

    Post, V.E.A.; Simmons, C.T.


    Using sand tank experiments and numerical models, local-scale solute-transport processes associated with free convection in both the region surrounding as well as within discrete low-permeability strata are explored. Different permeability geometries and contrasts between high- and low-permeability

  20. Scaling of postinjection-induced seismicity: An approach to assess hydraulic fracturing related processes (United States)

    Johann, Lisa; Dinske, Carsten; Shapiro, Serge


    Fluid injections into unconventional reservoirs have become a standard for the enhancement of fluid-mobility parameters. Microseismic activity during and after the injection can be frequently directly associated with subsurface fluid injections. Previous studies demonstrate that postinjection-induced seismicity has two important characteristics: On the one hand, the triggering front, which corresponds to early and distant events and envelops farthest induced events. On the other hand, the back front, which describes the lower boundary of the seismic cloud and envelops the aseismic domain evolving around the source after the injection stop. A lot of research has been conducted in recent years to understand seismicity-related processes. For this work, we follow the assumption that the diffusion of pore-fluid pressure is the dominant triggering mechanism. Based on Terzaghi's concept of an effective normal stress, the injection of fluids leads to increasing pressures which in turn reduce the effective normal stress and lead to sliding along pre-existing critically stressed and favourably oriented fractures and cracks. However, in many situations, spatio-temporal signatures of induced events are captured by a rather non-linear process of pore-fluid pressure diffusion, where the hydraulic diffusivity becomes pressure-dependent. This is for example the case during hydraulic fracturing where hydraulic transport properties are significantly enhanced. For a better understanding of processes related to postinjection-induced seismicity, we analytically describe the temporal behaviour of triggering and back fronts. We introduce a scaling law which shows that postinjection-induced events are sensitive to the degree of non-linearity and to the Euclidean dimension of the seismic cloud (see Johann et al., 2016, JGR). To validate the theory, we implement comprehensive modelling of non-linear pore-fluid pressure diffusion in 3D. We solve numerically for the non-linear equation of

  1. The evolution of galaxy metallicity scaling relations in cosmological hydrodynamical simulations (United States)

    De Rossi, M. E.; Theuns, T.; Font, A. S.; McCarthy, I. G.


    The evolution of the metal content of galaxies and its relations to other global properties [such as total stellar mass (M*), circular velocity, star formation rate (SFR), halo mass, etc.] provides important constraints on models of galaxy formation. Here we examine the evolution of metallicity scaling relations of simulated galaxies in the Galaxies-Intergalactic Medium Interaction Calculation suite of cosmological simulations. We make comparisons to observations of the correlation of gas-phase abundances with M* (the mass-metallicity relation, MZR), as well as with both M* and SFR or gas mass fraction (the so-called 3D fundamental metallicity relations, FMRs). The simulated galaxies follow the observed local MZR and FMRs over an order of magnitude in M*, but overpredict the metallicity of massive galaxies (log M* ≳ 10.5), plausibly due to inefficient feedback in this regime. We discuss the origin of the MZR and FMRs in the context of galactic outflows and gas accretion. We examine the evolution of MZRs defined using different elements that probe the three enrichment channels [SNII, SNIa, and asymptotic giant branch (AGB) stars]. Relations based on elements produced mainly by SNII evolve weakly, whereas those based on elements produced preferentially in SNIa/AGB exhibit stronger evolution, due to the longer time-scales associated with these channels. Finally, we compare the relations of central and satellite galaxies, finding systematically higher metallicities for satellites, as observed. We show that this is due to the removal of the metal-poor gas reservoir that normally surrounds galaxies and acts to dilute their gas-phase metallicity (via cooling/accretion on to the disc), but is lost due to ram-pressure stripping for satellites.


    Energy Technology Data Exchange (ETDEWEB)

    Cortese, L.; Glazebrook, K.; Mould, J. [Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, 3122 Victoria (Australia); Fogarty, L. M. R.; Bland-Hawthorn, J.; Croom, S. M.; Scott, N.; Allen, J. T.; Bloom, J.; Bryant, J. J. [Sydney Institute for Astronomy (SIfA), School of Physics, The University of Sydney, NSW 2006 (Australia); Ho, I.-T. [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Bekki, K. [ICRAR, The University of Western Australia, Crawley WA 6009 (Australia); Colless, M.; Sharp, R. [Research School of Astronomy and Astrophysics, The Australian National University, Cotter Road, Weston Creek, ACT 2611 (Australia); Couch, W.; Goodwin, M. [Australian Astronomical Observatory, P.O. Box 915, North Ryde, NSW 1670 (Australia); Tonini, C. [School of Physics, The University of Melbourne, VIC 3010 (Australia); Cluver, M. [Astronomy Department, University of Cape Town, Private Bag X3, Rondebosch 7701 (South Africa); Davies, R. L. [Astrophysics, Department of Physics, University of Oxford, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Drinkwater, M. J. [School of Mathematics and Physics, University of Queensland, QLD 4072 (Australia); and others


    We take advantage of the first data from the Sydney-AAO Multi-object Integral field Galaxy Survey to investigate the relation between the kinematics of gas and stars, and stellar mass in a comprehensive sample of nearby galaxies. We find that all 235 objects in our sample, regardless of their morphology, lie on a tight relation linking stellar mass (M {sub *}) to internal velocity quantified by the S {sub 0.5} parameter, which combines the contribution of both dispersion (σ) and rotational velocity (V {sub rot}) to the dynamical support of a galaxy (S{sub 0.5}=√(0.5 V{sub rot}{sup 2}+σ{sup 2})). Our results are independent of the baryonic component from which σ and V {sub rot} are estimated, as the S {sub 0.5} of stars and gas agree remarkably well. This represents a significant improvement compared to the canonical M {sub *} versus V {sub rot} and M {sub *} versus σ relations. Not only is no sample pruning necessary, but also stellar and gas kinematics can be used simultaneously, as the effect of asymmetric drift is taken into account once V {sub rot} and σ are combined. Our findings illustrate how the combination of dispersion and rotational velocities for both gas and stars can provide us with a single dynamical scaling relation valid for galaxies of all morphologies across at least the stellar mass range 8.5 relation appears to be more general and at least as tight as any other dynamical scaling relation, representing a unique tool for investigating the link between galaxy kinematics and baryonic content, and a less biased comparison with theoretical models.

  3. Estimation of sub-core permeability statistical properties from coreflooding data (United States)

    Rabinovich, Avinoam


    Knowledge of sub-core permeability is necessary for accurate numerical modeling of coreflooding experiments and for investigation of sub-core flow phenomenon. A new method for estimating sub-core permeability geometric mean (kG) and log-permeability variance (σy2) is presented. The method is based on matching coreflooding experiment measurements of wetting phase relative permeability with semi-analytical calculations of effective relative permeability. The semi-analytical solution is formulated assuming log-normal permeability (k), steady state and capillary-limit conditions. It is based on the geometric mean and log-phase-permeability variance for isotropic k and power law averaging for anisotropic correlations. The solution is validated on synthetic k realizations by comparison with numerical calculations. Then, the estimation method is tested on synthetic data assuming various types of core capillary pressure relationships, relative permeability functions and k anisotropies. Results demonstrate high accuracy in almost all of the cases except for small anisotropy ratios lh/lv between horizontal (lh) and vertical (lv) dimensionless correlation lengths, where flow is in the horizontal direction, and when σy2 is large. The method is also validated using data from CO2-brine coreflooding experiments conducted on two different cores. It is found that the estimation method remains accurate in these realistic settings, however, accuracy of kG is reduced when the core permeability departs from a log-normal distribution.

  4. L-Band SAR Backscatter Related to Forest Cover, Height and Aboveground Biomass at Multiple Spatial Scales across Denmark

    DEFF Research Database (Denmark)

    Joshi, Neha P.; Mitchard, Edward T A; Schumacher, Johannes


    DAR-derived maps of vegetation penetrability, height and AGB over Denmark at different spatial scales (50 m to 500 m). Trends in the relations indicate that, first, AGB retrieval accuracy from SAR improves most in mapping at 100-m scale instead of 50 m, and improvements are negligible beyond 250 m. Relative errors...... a strong linear relation (R2 = 0.79 at 250-m scale). In areas of high fractional forest cover, there is a slight decline in backscatter as AGB increases, indicating signal attenuation. The two results demonstrate that accounting for spatial scale and variations in forest structure, such as cover...

  5. Incremental Validity of the Subscales of the Emotional Regulation Related to Testing Scale for Predicting Test Anxiety (United States)

    Feldt, Ronald; Lindley, Kyla; Louison, Rebecca; Roe, Allison; Timm, Megan; Utinkova, Nikola


    The Emotional Regulation Related to Testing Scale (ERT Scale) assesses strategies students use to regulate emotion related to academic testing. It has four dimensions: Cognitive Appraising Processes (CAP), Emotion-Focusing Processes (EFP), Task-Focusing Processes (TFP), and Regaining Task-Focusing Processes (RTFP). The study examined the factor…

  6. The MUSIC of galaxy clusters - II. X-ray global properties and scaling relations (United States)

    Biffi, V.; Sembolini, F.; De Petris, M.; Valdarnini, R.; Yepes, G.; Gottlöber, S.


    We present the X-ray properties and scaling relations of a large sample of clusters extracted from the Marenostrum MUltidark SImulations of galaxy Clusters (MUSIC) data set. We focus on a sub-sample of 179 clusters at redshift z ˜ 0.11, with 3.2 × 1014 h-1 M⊙ MUSIC clusters reasonably resemble the self-similar prediction, especially for correlations involving TX. The observational approach also allows for a more direct comparison with real clusters, from which we find deviations mainly due to the physical description of the ICM, affecting TX and, particularly, LX.

  7. Modelling maximal oxygen uptake in athletes: allometric scaling versus ratio-scaling in relation to body mass. (United States)

    Chia, Michael; Aziz, Abdul Rashid


    Maximal oxygen uptake, V&O2 peak, among athletes is an important foundation for all training programmes to enhance competition performance. In Singapore, the V& O2 peak of athletes is apparently not widely known. There is also controversy in the modelling or scaling of maximal oxygen uptake for differences in body size - the use of ratio-scaling remains common but allometric scaling is gaining acceptance as the method of choice. One hundred fifty-eight male (age, 21.7 +/- 4.9 years; body mass, 64.8 +/- 8.6 kg) and 28 female (age, 21.9 +/- 7.0 years; body mass, 53.0 +/- 7.0 kg) athletes completed a maximal treadmill run to volitional exhaustion, to determine VO2 peak. V& O2 peak in L/min of female athletes was 67.8% that of male athletes (2.53 +/- 0.29 vs. 3.73 +/- 0.53 L/min), and V& O2 peak in mL/kg BM1.0/min of female athletes was 83.4% of male athletes (48.4 +/- 7.2 vs. 58.0 +/- 6.9 mL/kg BM1.0/min). Ratio-scaling of V& O2 peak did not create a size-free variable and was unsuitable as a scaling method. Instead, V& O2 peak, that was independent of the effect of body mass in male and female athletes, was best described using 2 separate and allometrically-derived sex-specific regression equations; these were V& O2 peak = 2.23 BM0.67 for male athletes and V& O2 peak = 2.23 BM0.24 for female athletes.

  8. Fracture network topology and characterization of structural permeability (United States)

    Hansberry, Rowan; King, Rosalind; Holford, Simon


    There are two fundamental requirements for successful geothermal development: elevated temperatures at accessible depths, and a reservoir from which fluids can be extracted. The Australian geothermal sector has successfully targeted shallow heat, however, due in part to the inherent complexity of targeting permeability, obtaining adequate flow rates for commercial production has been problematic. Deep sedimentary aquifers are unlikely to be viable geothermal resources due to the effects of diagenetic mineral growth on rock permeability. Therefore, it is likely structural permeability targets, exploiting natural or induced fracture networks will provide the primary means for fluid flow in geothermal, as well as unconventional gas, reservoirs. Recent research has focused on the pattern and generation of crustal stresses across Australia, while less is known about the resultant networks of faults, joints, and veins that can constitute interconnected sub-surface permeability pathways. The ability of a fracture to transmit fluid is controlled by the orientation and magnitude of the in-situ stress field that acts on the fracture walls, rock strength, and pore pressure, as well as fracture properties such as aperture, orientation, and roughness. Understanding the distribution, orientation and character of fractures is key to predicting structural permeability. This project focuses on extensive mapping of fractures over various scales in four key Australian basins (Cooper, Otway, Surat and Perth) with the potential to host geothermal resources. Seismic attribute analysis is used in concert with image logs from petroleum wells, and field mapping to identify fracture networks that are usually not resolved in traditional seismic interpretation. We use fracture network topology to provide scale-invariant characterisation of fracture networks from multiple data sources to assess similarity between data sources, and fracture network connectivity. These results are compared with

  9. Air sparging in low permeability soils

    Energy Technology Data Exchange (ETDEWEB)

    Marley, M.C. [Envirogen, Inc., Canton, MA (United States)


    Sparging technology is rapidly growing as a preferred, low cost remediation technique of choice at sites across the United States. The technology is considered to be commercially available and relatively mature. However, the maturity is based on the number of applications of the technology as opposed to the degree of understanding of the mechanisms governing the sparging process. Few well documented case studies exist on the long term operation of the technology. Sparging has generally been applied using modified monitoring well designs in uniform, coarse grained soils. The applicability of sparging for the remediation of DNAPLs in low permeability media has not been significantly explored. Models for projecting the performance of sparging systems in either soils condition are generally simplistic but can be used to provide general insight into the effects of significant changes in soil and fluid properties. The most promising sparging approaches for the remediation of DNAPLs in low permeability media are variations or enhancements to the core technology. Recirculatory sparging systems, sparging/biosparging trenches or curtains and heating or induced fracturing techniques appear to be the most promising technology variants for this type of soil. 21 refs., 9 figs.

  10. Regulation of intestinal permeability: The role of proteases. (United States)

    Van Spaendonk, Hanne; Ceuleers, Hannah; Witters, Leonie; Patteet, Eveline; Joossens, Jurgen; Augustyns, Koen; Lambeir, Anne-Marie; De Meester, Ingrid; De Man, Joris G; De Winter, Benedicte Y


    The gastrointestinal barrier is - with approximately 400 m 2 - the human body's largest surface separating the external environment from the internal milieu. This barrier serves a dual function: permitting the absorption of nutrients, water and electrolytes on the one hand, while limiting host contact with noxious luminal antigens on the other hand. To maintain this selective barrier, junction protein complexes seal the intercellular space between adjacent epithelial cells and regulate the paracellular transport. Increased intestinal permeability is associated with and suggested as a player in the pathophysiology of various gastrointestinal and extra-intestinal diseases such as inflammatory bowel disease, celiac disease and type 1 diabetes. The gastrointestinal tract is exposed to high levels of endogenous and exogenous proteases, both in the lumen and in the mucosa. There is increasing evidence to suggest that a dysregulation of the protease/antiprotease balance in the gut contributes to epithelial damage and increased permeability. Excessive proteolysis leads to direct cleavage of intercellular junction proteins, or to opening of the junction proteins via activation of protease activated receptors. In addition, proteases regulate the activity and availability of cytokines and growth factors, which are also known modulators of intestinal permeability. This review aims at outlining the mechanisms by which proteases alter the intestinal permeability. More knowledge on the role of proteases in mucosal homeostasis and gastrointestinal barrier function will definitely contribute to the identification of new therapeutic targets for permeability-related diseases.

  11. Validation of the mothers object relations scales in 2?4 year old children and comparison with the child?parent relationship scale


    Simkiss, Douglas E; MacCallum, Fiona; Fan, Emma EY; Oates, John M; Kimani, Peter K; Stewart-Brown, Sarah


    Background\\ud \\ud The quality of the parent–child relationship has an important effect on a wide range of child outcomes. The evaluation of interventions to promote healthy parenting and family relationships is dependent on outcome measures which can quantify the quality of parent–child relationships. Between the Mothers’ Object Relations – Short Form (MORS-SF) scale for babies and the Child–parent Relationship Scale (C-PRS) there is an age gap where no validated scales are available. We repo...


    Energy Technology Data Exchange (ETDEWEB)

    Graham, Alister W. [Centre for Astrophysics and Supercomputing, Swinburne University of Technology, Hawthorn, VIC 3122 (Australia); Scott, Nicholas [Sydney Institute for Astronomy, School of Physics, University of Sydney, NSW 2006 (Australia)


    Several recent papers have reported on the occurrence of active galactic nuclei (AGNs) containing undermassive black holes relative to a linear scaling relation between black hole mass (M {sub bh}) and host spheroid stellar mass (M {sub sph,} {sub *}). However, dramatic revisions to the M {sub bh}-M {sub sph,} {sub *} and M {sub bh}-L {sub sph} relations, based on samples containing predominantly inactive galaxies, have recently identified a new steeper relation at M {sub bh} ≲ (2-10) × 10{sup 8} M {sub ☉}, roughly corresponding to M {sub sph,} {sub *} ≲ (0.3-1) × 10{sup 11} M {sub ☉}. We show that this steeper, quadratic-like M {sub bh}-M {sub sph,} {sub *} relation defined by the Sérsic galaxies, i.e., galaxies without partially depleted cores, roughly tracks the apparent offset of the AGN having 10{sup 5} ≲ M {sub bh}/M {sub ☉} ≲ 0.5 × 10{sup 8}. That is, these AGNs are not randomly offset with low black hole masses, but also follow a steeper (nonlinear) relation. As noted by Busch et al., confirmation or rejection of a possible AGN offset from the steeper M {sub bh}-M {sub sph,} {sub *} relation defined by the Sérsic galaxies will benefit from improved stellar mass-to-light ratios for the spheroids hosting these AGNs. Several implications for formation theories are noted. Furthermore, reasons for possible under- and overmassive black holes, the potential existence of intermediate mass black holes (<10{sup 5} M {sub ☉}), and the new steep (black hole)-(nuclear star cluster) relation, M{sub bh}∝M{sub nc}{sup 2.7±0.7}, are also discussed.

  13. Extended general relativity: Large-scale antigravity and short-scale gravity with ω=-1 from five-dimensional vacuum (United States)

    Madriz Aguilar, José Edgar; Bellini, Mauricio


    Considering a five-dimensional (5D) Riemannian spacetime with a particular stationary Ricci-flat metric, we obtain in the framework of the induced matter theory an effective 4D static and spherically symmetric metric which give us ordinary gravitational solutions on small (planetary and astrophysical) scales, but repulsive (anti gravitational) forces on very large (cosmological) scales with ω=-1. Our approach is an unified manner to describe dark energy, dark matter and ordinary matter. We illustrate the theory with two examples, the solar system and the great attractor. From the geometrical point of view, these results follow from the assumption that exists a confining force that make possible that test particles move on a given 4D hypersurface.

  14. Extended general relativity: Large-scale antigravity and short-scale gravity with {omega}=-1 from five-dimensional vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Madriz Aguilar, Jose Edgar [Instituto de Fisica de la Universidad de Guanajuato, C.P. 37150, Leon Guanajuato (Mexico); Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3350, C.P. 7600, Mar del Plata (Argentina)], E-mail:; Bellini, Mauricio [Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Funes 3350, C.P. 7600, Mar del Plata (Argentina); Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET) (Argentina)], E-mail:


    Considering a five-dimensional (5D) Riemannian spacetime with a particular stationary Ricci-flat metric, we obtain in the framework of the induced matter theory an effective 4D static and spherically symmetric metric which give us ordinary gravitational solutions on small (planetary and astrophysical) scales, but repulsive (anti gravitational) forces on very large (cosmological) scales with {omega}=-1. Our approach is an unified manner to describe dark energy, dark matter and ordinary matter. We illustrate the theory with two examples, the solar system and the great attractor. From the geometrical point of view, these results follow from the assumption that exists a confining force that make possible that test particles move on a given 4D hypersurface.

  15. Diabetes-related emotional distress in adults: reliability and validity of the Norwegian versions of the Problem Areas in Diabetes Scale (PAID) and the Diabetes Distress Scale (DDS). (United States)

    Graue, Marit; Haugstvedt, Anne; Wentzel-Larsen, Tore; Iversen, Marjolein M; Karlsen, Bjørg; Rokne, Berit


    Regular assessment of diabetes-related emotional distress is recommended to identify high-risk people with diabetes and to further prevent negative effects on self-management. Nevertheless, psychological problems are greatly under diagnosed. Translating and testing instruments for psychosocial assessment across languages, countries and cultures allow for further research collaboration and enhance the prospect of improving treatment and care. To examine the psychometric properties of the Norwegian versions of the Problem Areas in Diabetes Scale and the Diabetes Distress Scale. Cross-sectional survey design. A sample comprising adults with diabetes (response rate 71%) completed the Problem Areas in Diabetes Scale and the Diabetes Distress Scale, which were translated into Norwegian with standard forward-backwards translation. The study included 292 participants with type 1 (80%) and type 2 diabetes (20%) aged 18-69 years, 58% males, mean diabetes duration 17.3 years (11.6), mean HbA(1c) 8.2% (1.6). We used exploratory factor analysis with principal axis factoring and varimax rotation to investigate the factor structure and performed confirmatory factor analysis to test the best fit of a priori-defined models. Convergent and discriminate validity were examined using the Short Form-36 Health Survey, Hospital Anxiety and Depression Scale and demographic and disease-related clinical variables. We explored reliability by internal consistency and test-retest analysis. Exploratory factor analysis supported a four-factor model for the Diabetes Distress Scale. Confirmatory factor analysis indicated that the data and the hypothesized model for the Diabetes Distress Scale fit acceptably but not for the Problem Areas in Diabetes Scale. Greater distress assessed with both instruments correlated moderately with lower health-related quality of life and greater anxiety and depression. The instruments discriminated between those having additional health conditions or disabilities

  16. Small-scale health-related indicator acquisition using secondary data spatial interpolation

    Directory of Open Access Journals (Sweden)

    Thompson Mary E


    Full Text Available Abstract Background Due to the lack of small-scale neighbourhood-level health related indicators, the analysis of social and spatial determinants of health often encounter difficulties in assessing the interrelations of neighbourhood and health. Although secondary data sources are now becoming increasingly available, they usually cannot be directly utilized for analysis in other than the designed study due to sampling issues. This paper aims to develop data handling and spatial interpolation procedures to obtain small area level variables using the Canadian Community Health Surveys (CCHS data so that meaningful small-scale neighbourhood level health-related indicators can be obtained for community health research and health geographical analysis. Results Through the analysis of spatial autocorrelation, cross validation comparison, and modeled effect comparison with census data, kriging is identified as the most appropriate spatial interpolation method for obtaining predicted values of CCHS variables at unknown locations. Based on the spatial structures of CCHS data, kriging parameters are suggested and potential small-area-level health-related indicators are derived. An empirical study is conducted to demonstrate the effective use of derived neighbourhood variables in spatial statistical modeling. Suggestions are also given on the accuracy, reliability and usage of the obtained small area level indicators, as well as further improvements of the interpolation procedures. Conclusions CCHS variables are moderately spatially autocorrelated, making kriging a valid method for predicting values at unsampled locations. The derived variables are reliable but somewhat smoother, with smaller variations than the real values. As potential neighbourhood exposures in spatial statistical modeling, these variables are more suitable to be used for exploring potential associations than for testing the significance of these associations, especially for associations

  17. Scaling Relations for the Efficiency of Radial Migration in Disk Galaxies (United States)

    Daniel, Kathryne J.


    Radial migration is frequently recognized as an internal, secular process that could play an important role in disk galaxy evolution. The driving mechanism for radial migration is transient spiral patterns, which rearrange the orbital angular momentum distribution of disk stars around corotation without causing kinematic heating. Should radial migration be an efficient process, it could cause a substantial fraction of disk stars to move large radial distances over the lifetime of the disk, thus having a significant impact on the disk’s kinematic, structural and chemical evolution. Observational and simulated data are consistent with radial migration being important for kinematically cold stellar populations and less so for populations with hot kinematics. I will present an analytic criterion that determines which stars are in orbits that could lead to radial migration. I will then show some scaling relations for the efficacy of radial migration that result from applying this analytic criterion to a series of models that have a variety of distribution functions and spiral patterns in systems with an assumed flat rotation curve. Most importantly, I will argue that these scaling relations can be used to place constraints on the efficiency of radial migration, where stronger spiral patterns and kinematically cold populations will lead to a higher fraction of stars in orbits that can lead to radial migration.

  18. Flow and permeability structure of the Beowawe, Nevada hydrothermal system

    Energy Technology Data Exchange (ETDEWEB)

    Faulder, D.D. [Lockheed Idaho Technologies Co., Idaho Falls, ID (United States); Johnson, S.D.; Benoit, W.R. [Oxbow Power Services, Inc., Reno, NV (United States)


    A review of past geologic, geochemical, hydrological, pressure transient, and reservoir engineering studies of Beowawe suggests a different picture of the reservoir than previously presented. The Beowawe hydrothermal contains buoyant thermal fluid dynamically balanced with overlying cold water, as shown by repeated temperature surveys and well test results. Thermal fluid upwells from the west of the currently developed reservoir at the intersection of the Malpais Fault and an older structural feature associated with mid-Miocene rifting. A tongue of thermal fluid rises to the east up the high permeability Malpais Fault, discharges at the Geysers area, and is in intimate contact with overlying cooler water. The permeability structure is closely related to the structural setting, with the permeability of the shallow hydrothermal system ranging from 500 to 1,000 D-ft, while the deeper system ranges from 200 to 400 D-ft.

  19. An intelligent detecting system for permeability prediction of MBR. (United States)

    Han, Honggui; Zhang, Shuo; Qiao, Junfei; Wang, Xiaoshuang


    The membrane bioreactor (MBR) has been widely used to purify wastewater in wastewater treatment plants. However, a critical difficulty of the MBR is membrane fouling. To reduce membrane fouling, in this work, an intelligent detecting system is developed to evaluate the performance of MBR by predicting the membrane permeability. This intelligent detecting system consists of two main parts. First, a soft computing method, based on the partial least squares method and the recurrent fuzzy neural network, is designed to find the nonlinear relations between the membrane permeability and the other variables. Second, a complete new platform connecting the sensors and the software is built, in order to enable the intelligent detecting system to handle complex algorithms. Finally, the simulation and experimental results demonstrate the reliability and effectiveness of the proposed intelligent detecting system, underlying the potential of this system for the online membrane permeability for detecting membrane fouling of MBR.

  20. Estimation of source parameters and scaling relations for moderate size earthquakes in North-West Himalaya (United States)

    Kumar, Vikas; Kumar, Dinesh; Chopra, Sumer


    The scaling relation and self similarity of earthquake process have been investigated by estimating the source parameters of 34 moderate size earthquakes (mb 3.4-5.8) occurred in the NW Himalaya. The spectral analysis of body waves of 217 accelerograms recorded at 48 sites have been carried out using in the present analysis. The Brune's ω-2 model has been adopted for this purpose. The average ratio of the P-wave corner frequency, fc(P), to the S-wave corner frequency, fc(S), has been found to be 1.39 with fc(P) > fc(S) for 90% of the events analyzed here. This implies the shift in the corner frequency in agreement with many other similar studies done for different regions. The static stress drop values for all the events analyzed here lie in the range 10-100 bars average stress drop value of the order of 43 ± 19 bars for the region. This suggests the likely estimate of the dynamic stress drop, which is 2-3 times the static stress drop, is in the range of about 80-120 bars. This suggests the relatively high seismic hazard in the NW Himalaya as high frequency strong ground motions are governed by the stress drop. The estimated values of stress drop do not show significant variation with seismic moment for the range 5 × 1014-2 × 1017 N m. This observation along with the cube root scaling of corner frequencies suggests the self similarity of the moderate size earthquakes in the region. The scaling relation between seismic moment and corner frequency Mo fc3 = 3.47 ×1016Nm /s3 estimated in the present study can be utilized to estimate the source dimension given the seismic moment of the earthquake for the hazard assessment. The present study puts the constrains on the important parameters stress drop and source dimension required for the synthesis of strong ground motion from the future expected earthquakes in the region. Therefore, the present study is useful for the seismic hazard and risk related studies for NW Himalaya.

  1. Age-Related Differences in OMNI-RPE Scale Validity in Youth: A Longitudinal Analysis. (United States)

    Gammon, Catherine; Pfeiffer, Karin A; Pivarnik, James M; Moore, Rebecca W; Rice, Kelly R; Trost, Stewart G


    RPE scales are used in exercise science research to assess perceptions of physical effort. RPE scale validity has been evaluated by assessing correlations between RPE and physiological indicators. Cross-sectional studies indicate that RPE scale validity improves with age; however, this has not been studied longitudinally. This study aimed to examine age-related trends in OMNI-RPE scale validity, using a longitudinal study design, and HR and oxygen uptake (V˙O2) as criterion measures. Participants performed eleven 5-min activity trials at baseline, 12-, 24-, and 36-month follow-up (V˙O2 data: N = 160; HR data: N = 138). HR and V˙O2 between minutes 2.5 and 4.5 of each activity were recorded. At the end of each activity, participants reported RPE. Children were stratified into the following age-groups: 6-8, 9-10, 11-12, and ≥13 yr. Within-subject correlations between OMNI-RPE and HR/V˙O2 were calculated at each time point. Differences between correlations for consecutive time points were evaluated using 95% confidence intervals. Among children age 6-8 yr at baseline, correlations progressed from 0.67 to 0.78 (V˙O2) and from 0.70 to 0.79 (HR) for 36 months. Among children age 9-10 yr at baseline, the mean within-subject correlation was 0.78 at baseline and 0.81 at 36-month follow-up. Among children age 11-12 and ≥13 yr at baseline, OMNI-RPE ratings demonstrated strong validity (r ≥ 0.82) at each time point. For the 36-month follow-up, OMNI-RPE scale validity improved among children age 6-8 yr at baseline and remained strong among children age 9-10, 11-12, and ≥13 yr at baseline. Moderate correlations for the youngest participants suggest that caution should be used when interpreting OMNI-RPE reports from children younger than 8 yr.

  2. Permeability Evolution of Propped Artificial Fractures in Green River Shale (United States)

    Li, Xiang; Feng, Zijun; Han, Gang; Elsworth, Derek; Marone, Chris; Saffer, Demian; Cheon, Dae-Sung


    This paper compares the evolution of permeability with effective stress in propped fractures in shale for native CH4 compared with that for sorbing CO2, slightly sorbing N2 and non-sorbing He. We examine the response for laboratory experiments on artificial propped fractures in Green River Shale to explore mechanisms of proppant embedment and fracture diagenesis. Split cylindrical specimens sandwich a proppant bead-pack at a constant confining stress of 20 MPa and with varied pore pressure. Permeability and sorption characteristics are measured with the pulse transient method. To explore the effect of swelling and embedment on fracture surface geometry, we measure the evolution of conductivity characteristics for different proppant geometries (single layer vs. multilayer), gas saturation and specimen variation in order to simulate both production and enhanced gas recovery. The resulting morphology of embedment is measured by white light interferometry and characterized via surface roughness parameter of mean, maximum and root-mean-square amplitudes. For both strongly (CO2, CH4) and slightly adsorptive gases (N2), the permeability first decreases with an increase in gas pressure due to swelling before effective stress effects dominate above the Langmuir pressure threshold. CO2 with its highest adsorption affinity produces the lowest permeability among these three gas permeants. Monolayer propped specimens show maximum swelling and lowered k/k 0 ratio and increased embedment recorded in the surface roughness relative to the multilayered specimens. Permeabilities measured for both injection and depletion cycles generally overlap and are repeatable with little hysteresis. This suggests the dominant role of reversible swelling over irreversible embedment. Gas permeant composition and related swelling have an important effect on the permeability evolution of shales.

  3. Experimental Study on Permeability of Concrete (United States)

    Yang, Honglu; Liu, Rentai; Zheng, Zhuo; Liu, Haojie; Gao, Yan; Liu, Yankai


    To study the influencing factors on permeability of pervious concrete, by adding inorganic organic composite materials obtained experimental results show that different aggregate size, aggregate cement ratio of different, different water cement ratio on the permeability performance. The permeability of the concrete was tested by using the self - made permeable device. The experimental results showed that the permeation coefficient of the experiment was obtained and the factors influencing the permeability of the concrete were compared and analyzed. At the same time, the porosity of pervious concrete was measured, the influence of various variables on porosity was studied, and the influence of various factors on the permeability of voids was found. Finally, through comprehensive analysis of a variety of factors, the optimal water cement ratio is 0.28. At this time, the pervious performance of concrete is optimal.

  4. Air permeability of polyester nonwoven fabrics

    Directory of Open Access Journals (Sweden)

    Zhu Guocheng


    Full Text Available Air permeability is one of the most important properties of non-woven fabrics in many applications. This paper aims to investigate the effects of thickness, porosity and density on the air permeability of needle-punched non-woven fabrics and compare the experimental values with two models which are based on hydraulic radius theory and drag theory, respectively. The air permeability of the samples was measured by an air permeability tester FX3300. The results showed that the air permeability of non-woven fabrics decreased with the increase in thickness and density of samples, increased with the increase of porosity, and the air permeability was not directly proportional to the pressure gradient. Meanwhile, the prediction model based on hydraulic radius theory had a better agreement with experimental values than the model based on drag theory, but the values were much higher than the experimental results, especially for higher porosity and higher pressure gradient.

  5. Intestinal Permeability before and after Ibuprofen in Families of Children with Crohn’s Disease

    Directory of Open Access Journals (Sweden)

    Samuel A Zamora


    Full Text Available BACKGROUND: Members of a subset of first-degree relatives of adults with Crohn’s disease have been shown to have an increased baseline intestinal permeability and/or an exaggerated increase in intestinal permeability after the administration of acetylsalicylic acid.

  6. Determination of Three-Phase Relative Permeabilities under Reservoir Conditions by Hot Water and Steamflood Experiments Détermination de perméabilités relatives tri-phasiques en conditions de réservoir, à partir d'expériences de balayages à l'eau chaude et à la vapeur

    Directory of Open Access Journals (Sweden)

    Quettier L.


    Full Text Available In order to help the physical and numerical interpretation of Emeraude's steam pilot, two-phase waterfloods at four temperatures (between 30 and 240°C and a steamflood were performed in the laboratory using the same porous medium (compacted silt and under reservoir conditions. Dynamic isothermal displacements were interpreted with a thermal simulator taking into account capillary end effects. The corresponding oil-water relative permeability curves were obtained by matching observed pressure drop and oil production. Results show that temperature influences the end-point saturations but not the shape of the curves. The steamflood experiment was carried out in an adiabatic core holder. Oil stripping and production of a large amount of CO2 caused by dissolution of carbonates were pointed out. The numerical interpretation of this experiment, by making use of the oil-water relative permeabilities, provided the three-phase oil relative permeability which is an essential datum for numerical interpretation of a steam drive pilot. Then a parameter study was used to quantify the influence of the different mechanisms involved in hot water and steam floods. Dans le but de faciliter l'interprétation physique et numérique du pilote vapeur d' Emeraude, des balayages eau-huile à quatre températures (entre 30 et 240°C et un balayage à la vapeur ont été réalisés au laboratoire. Toutes ces expériences ont été effectuées sur le même milieu poreux (silt compacté et en conditions de réservoir. Les déplacements bi-phasiques isothermes, en écoulement transitoire, ont été interprétés avec un modèle numérique thermique qui prend en compte les effets capillaires aux extrémités de l'échantillon. Les courbes de perméabilités relatives dynamiques eau-huile sont déterminées par calage, sur les courbes expérimentales, de la différence de pression et de la production d'huile simulées. Les résultats montrent que la température influe sur les

  7. Analysis of environmental issues related to small-scale hydroelectric development. III. Water level fluctuation

    Energy Technology Data Exchange (ETDEWEB)

    Hildebrand, S.G. (ed.)


    Potential environmental impacts in reservoirs and downstream river reaches below dams that may be caused by the water level fluctuation resulting from development and operation of small scale (under 25MW) hydroelectric projects are identified. The impacts discussed will be of potential concern at only those small-scale hydroelectric projects that are operated in a store and release (peaking) mode. Potential impacts on physical and chemical characteristics in reservoirs resulting from water level fluctuation include resuspension and redistribution of bank and bed sediment; leaching of soluble organic matter from sediment in the littoral zone; and changes in water quality resulting from changes in sediment and nutrient trap efficiency. Potential impacts on reservoir biota as a result of water level fluctuation include habitat destruction and the resulting partial or total loss of aquatic species; changes in habitat quality, which result in reduced standing crop and production of aquatic biota; and possible shifts in species diversity. The potential physical effects of water level fluctuation on downstream systems below dams are streambed and bank erosion and water quality problems related to resuspension and redistribution of these materials. Potential biological impacts of water level fluctuation on downstream systems below dams result from changes in current velocity, habitat reduction, and alteration in food supply. These alterations, either singly or in combination, can adversely affect aquatic populations below dams. The nature and potential significance of adverse impacts resulting from water level fluctuation are discussed. Recommendations for site-specific evaluation of water level fluctuation at small-scale hydroelectric projects are presented.

  8. Integrated petrophysical and reservoir characterization workflow to enhance permeability and water saturation prediction (United States)

    Al-Amri, Meshal; Mahmoud, Mohamed; Elkatatny, Salaheldin; Al-Yousef, Hasan; Al-Ghamdi, Tariq


    Accurate estimation of permeability is essential in reservoir characterization and in determining fluid flow in porous media which greatly assists optimize the production of a field. Some of the permeability prediction techniques such as Porosity-Permeability transforms and recently artificial intelligence and neural networks are encouraging but still show moderate to good match to core data. This could be due to limitation to homogenous media while the knowledge about geology and heterogeneity is indirectly related or absent. The use of geological information from core description as in Lithofacies which includes digenetic information show a link to permeability when categorized into rock types exposed to similar depositional environment. The objective of this paper is to develop a robust combined workflow integrating geology and petrophysics and wireline logs in an extremely heterogeneous carbonate reservoir to accurately predict permeability. Permeability prediction is carried out using pattern recognition algorithm called multi-resolution graph-based clustering (MRGC). We will bench mark the prediction results with hard data from core and well test analysis. As a result, we showed how much better improvements are achieved in the permeability prediction when geology is integrated within the analysis. Finally, we use the predicted permeability as an input parameter in J-function and correct for uncertainties in saturation calculation produced by wireline logs using the classical Archie equation. Eventually, high level of confidence in hydrocarbon volumes estimation is reached when robust permeability and saturation height functions are estimated in presence of important geological details that are petrophysically meaningful.

  9. Vascular permeability in cerebral cavernous malformations. (United States)

    Mikati, Abdul G; Khanna, Omaditya; Zhang, Lingjiao; Girard, Romuald; Shenkar, Robert; Guo, Xiaodong; Shah, Akash; Larsson, Henrik B W; Tan, Huan; Li, Luying; Wishnoff, Matthew S; Shi, Changbin; Christoforidis, Gregory A; Awad, Issam A


    Patients with the familial form of cerebral cavernous malformations (CCMs) are haploinsufficient for the CCM1, CCM2, or CCM3 gene. Loss of corresponding CCM proteins increases RhoA kinase-mediated endothelial permeability in vitro, and in mouse brains in vivo. A prospective case-controlled observational study investigated whether the brains of human subjects with familial CCM show vascular hyperpermeability by dynamic contrast-enhanced quantitative perfusion magnetic resonance imaging, in comparison with CCM cases without familial disease, and whether lesional or brain vascular permeability correlates with CCM disease activity. Permeability in white matter far (WMF) from lesions was significantly greater in familial than in sporadic cases, but was similar in CCM lesions. Permeability in WMF increased with age in sporadic patients, but not in familial cases. Patients with more aggressive familial CCM disease had greater WMF permeability compared to those with milder disease phenotype, but similar lesion permeability. Subjects receiving statin medications for routine cardiovascular indications had a trend of lower WMF, but not lesion, permeability. This is the first demonstration of brain vascular hyperpermeability in humans with an autosomal dominant disease, as predicted mechanistically. Brain permeability, more than lesion permeability, may serve as a biomarker of CCM disease activity, and help calibrate potential drug therapy.

  10. The Permeability of Boolean Sets of Cylinders

    Directory of Open Access Journals (Sweden)

    Willot F.


    Full Text Available Numerical and analytical results on the permeability of Boolean models of randomly-oriented cylinders with circular cross-section are reported. The present work investigates cylinders of prolate (highly-elongated and oblate (nearly flat types. The fluid flows either inside or outside of the cylinders. The Stokes flow is solved using full-fields Fourier-based computations on 3D binarized microstructures. The permeability is given for varying volume fractions of pores. A new upper-bound is derived for the permeability of the Boolean model of oblate cylinders. The behavior of the permeability in the dilute limit is discussed.

  11. Vascular permeability in cerebral cavernous malformations (United States)

    Mikati, Abdul G; Khanna, Omaditya; Zhang, Lingjiao; Girard, Romuald; Shenkar, Robert; Guo, Xiaodong; Shah, Akash; Larsson, Henrik BW; Tan, Huan; Li, Luying; Wishnoff, Matthew S; Shi, Changbin; Christoforidis, Gregory A; Awad, Issam A


    Patients with the familial form of cerebral cavernous malformations (CCMs) are haploinsufficient for the CCM1, CCM2, or CCM3 gene. Loss of corresponding CCM proteins increases RhoA kinase-mediated endothelial permeability in vitro, and in mouse brains in vivo. A prospective case-controlled observational study investigated whether the brains of human subjects with familial CCM show vascular hyperpermeability by dynamic contrast-enhanced quantitative perfusion magnetic resonance imaging, in comparison with CCM cases without familial disease, and whether lesional or brain vascular permeability correlates with CCM disease activity. Permeability in white matter far (WMF) from lesions was significantly greater in familial than in sporadic cases, but was similar in CCM lesions. Permeability in WMF increased with age in sporadic patients, but not in familial cases. Patients with more aggressive familial CCM disease had greater WMF permeability compared to those with milder disease phenotype, but similar lesion permeability. Subjects receiving statin medications for routine cardiovascular indications had a trend of lower WMF, but not lesion, permeability. This is the first demonstration of brain vascular hyperpermeability in humans with an autosomal dominant disease, as predicted mechanistically. Brain permeability, more than lesion permeability, may serve as a biomarker of CCM disease activity, and help calibrate potential drug therapy. PMID:25966944

  12. Snake scales, partial exposure, and the Snake Detection Theory: A human event-related potentials study (United States)

    Van Strien, Jan W.; Isbell, Lynne A.


    Studies of event-related potentials in humans have established larger early posterior negativity (EPN) in response to pictures depicting snakes than to pictures depicting other creatures. Ethological research has recently shown that macaques and wild vervet monkeys respond strongly to partially exposed snake models and scale patterns on the snake skin. Here, we examined whether snake skin patterns and partially exposed snakes elicit a larger EPN in humans. In Task 1, we employed pictures with close-ups of snake skins, lizard skins, and bird plumage. In task 2, we employed pictures of partially exposed snakes, lizards, and birds. Participants watched a random rapid serial visual presentation of these pictures. The EPN was scored as the mean activity (225–300 ms after picture onset) at occipital and parieto-occipital electrodes. Consistent with previous studies, and with the Snake Detection Theory, the EPN was significantly larger for snake skin pictures than for lizard skin and bird plumage pictures, and for lizard skin pictures than for bird plumage pictures. Likewise, the EPN was larger for partially exposed snakes than for partially exposed lizards and birds. The results suggest that the EPN snake effect is partly driven by snake skin scale patterns which are otherwise rare in nature. PMID:28387376

  13. Predictive permeability model of faults in crystalline rocks; verification by joint hydraulic factor (JH) obtained from water pressure tests (United States)

    Barani, Hamidreza Rostami; Lashkaripour, Gholamreza; Ghafoori, Mohammad


    In the present study, a new model is proposed to predict the permeability per fracture in the fault zones by a new parameter named joint hydraulic factor (JH). JH is obtained from Water Pressure Test (WPT) and modified by the degree of fracturing. The results of JH correspond with quantitative fault zone descriptions, qualitative fracture, and fault rock properties. In this respect, a case study was done based on the data collected from Seyahoo dam site located in the east of Iran to provide the permeability prediction model of fault zone structures. Datasets including scan-lines, drill cores, and water pressure tests in the terrain of Andesite and Basalt rocks were used to analyse the variability of in-site relative permeability of a range from fault zones to host rocks. The rock mass joint permeability quality, therefore, is defined by the JH. JH data analysis showed that the background sub-zone had commonly fracture, whereas the fault core had permeability characteristics nearly as low as the outer damage zone, represented by 8 Lu (1.3 ×10-4 m 3/s) per fracture, with occasional peaks towards 12 Lu (2 ×10-4 m 3/s) per fracture. The maximum JH value belongs to the inner damage zone, marginal to the fault core, with 14-22 Lu (2.3 ×10-4-3.6 ×10-4 m 3/s) per fracture, locally exceeding 25 Lu (4.1 ×10-4 m 3/s) per fracture. This gives a proportional relationship for JH approximately 1:4:2 between the fault core, inner damage zone, and outer damage zone of extensional fault zones in crystalline rocks. The results of the verification exercise revealed that the new approach would be efficient and that the JH parameter is a reliable scale for the fracture permeability change. It can be concluded that using short duration hydraulic tests (WPTs) and fracture frequency (FF) to calculate the JH parameter provides a possibility to describe a complex situation and compare, discuss, and weigh the hydraulic quality to make predictions as to the permeability models and

  14. Soil organic matter dynamics and CO2 fluxes in relation to landscape scale processes: linking process understanding to regional scale carbon mass-balances (United States)

    Van Oost, Kristof; Nadeu, Elisabet; Wiaux, François; Wang, Zhengang; Stevens, François; Vanclooster, Marnik; Tran, Anh; Bogaert, Patrick; Doetterl, Sebastian; Lambot, Sébastien; Van wesemael, Bas


    In this paper, we synthesize the main outcomes of a collaborative project (2009-2014) initiated at the UCL (Belgium). The main objective of the project was to increase our understanding of soil organic matter dynamics in complex landscapes and use this to improve predictions of regional scale soil carbon balances. In a first phase, the project characterized the emergent spatial variability in soil organic matter storage and key soil properties at the regional scale. Based on the integration of remote sensing, geomorphological and soil analysis techniques, we quantified the temporal and spatial variability of soil carbon stock and pool distribution at the local and regional scales. This work showed a linkage between lateral fluxes of C in relation with sediment transport and the spatial variation in carbon storage at multiple spatial scales. In a second phase, the project focused on characterizing key controlling factors and process interactions at the catena scale. In-situ experiments of soil CO2 respiration showed that the soil carbon response at the catena scale was spatially heterogeneous and was mainly controlled by the catenary variation of soil physical attributes (soil moisture, temperature, C quality). The hillslope scale characterization relied on advanced hydrogeophysical techniques such as GPR (Ground Penetrating Radar), EMI (Electromagnetic induction), ERT (Electrical Resistivity Tomography), and geophysical inversion and data mining tools. Finally, we report on the integration of these insights into a coupled and spatially explicit model and its application. Simulations showed that C stocks and redistribution of mass and energy fluxes are closely coupled, they induce structured spatial and temporal patterns with non negligible attached uncertainties. We discuss the main outcomes of these activities in relation to sink-source behavior and relevance of erosion processes for larger-scale C budgets.

  15. Universal scaling relations for the energies of many-electron Hooke atoms (United States)

    Odriazola, A.; Solanpää, J.; Kylänpää, I.; González, A.; Räsänen, E.


    A three-dimensional harmonic oscillator consisting of N ≥2 Coulomb-interacting charged particles, often called a (many-electron) Hooke atom, is a popular model in computational physics for, e.g., semiconductor quantum dots and ultracold ions. Starting from Thomas-Fermi theory, we show that the ground-state energy of such a system satisfies a nontrivial relation: Eg s=ω N4 /3fg s(β N1 /2) , where ω is the oscillator strength, β is the ratio between Coulomb and oscillator characteristic energies, and fg s is a universal function. We perform extensive numerical calculations to verify the applicability of the relation. In addition, we show that the chemical potentials and addition energies also satisfy approximate scaling relations. In all cases, analytic expressions for the universal functions are provided. The results have predictive power in estimating the key ground-state properties of the system in the large-N limit, and can be used in the development of approximative methods in electronic structure theory.

  16. A Local Baseline of the Black Hole Mass - Host Galaxy Scaling Relations for Active Galaxies (United States)

    Bennert, Vardha


    The discovery of relations between supermassive black holes (BHs) and their host-galaxy properties has sparked many observational studies pertaining both to the local Universe and cosmic history. Nevertheless, a clear understanding of their origin and fundamental drivers still eludes us. Studying the evolution of these relations depends on our understanding of the slope and scatter of local relations for active galaxies (AGNs). We propose a SNAP program of a unique sample of 84 local type-1 AGNs, spanning a wide range of BH masses (MBH), morphologies, and stellar masses. The high resolution WFC3/F814W images are essential for a detailed decomposition of the host-galaxy in the presence of a bright AGN point source, resulting in precise measurements of the different host-galaxy components and AGN luminosity free of host-galaxy contamination for a robust determination of MBH. When complemented with spatially-resolved Keck spectra to determine stellar-velocity dispersion within bulge effective radius, this yields a most complete baseline of host-galaxy properties over the entire range of MBH scaling relations. A typical SNAP completion rate results in a sample of 30 objects which will be used to calibrate existing Gemini NIRI and SDSS images. We will study slope and scatter of the relations, dependencies and fundamental drivers. The frequency of pseudo-bulges, bars, and (minor) mergers will reveal the dominant growth mechanism of spheroids. The homogeneous sample will identify any selection biases in the reverberation-mapped AGN sample which serves as a MBH calibrator for the entire Universe. Results will be compared with state-of-the-art semi-analytical models.

  17. Cumulative Relative Reactivity: A Concept for Modeling Aquifer-Scale Reactive Transport (United States)

    Loschko, M.; Cirpka, O. A.; Wöhling, T.; Rudolph, D. L.


    Quantitative understanding of pollutant fluxes from diffuse input and turnover of pollutants at catchment scale requires process-based numerical models that can explain observed time series of heads, fluxes, and concentrations. To deal with the high level of uncertainty a probabilistic framework is necessary. Due to the high computational effort, such evaluations cannot be done with a spatially explicit reactive-transport model. Conceptual simplifications are needed. The proposed approach is based on travel times and relative reactivity. The latter quantifies the intensity of the chemical reaction relative to a reference reaction rate and can be interpreted as the strength of electron-donor (or electron-acceptor) released by the matrix. In general, the relative reactivity is a spatially variable property reflecting the geology of the formation. In this approach, the paths of individual water parcels are tracked through the aquifer, the age of the water parcels is evaluated, and the relative reactivity is integrated along their trajectories. By switching from space-time discretization to cumulative relative reactivity, advective-reactive transport can be simulated by solving a single system of ordinary differential equations for each combination of concentrations in the inflow. In comparison to solving the advection-dispersion-reaction equation in a spatially explicit way, solving a limited number of ordinary differential equations is computationally significantly less costly. This permits the application of Monte-Carlo methods within a stochastic framework. The validity of the approach was tested in a two-dimensional test case, where the errors introduced by neglecting dispersive mixing were analyzed. The applicability of the approach is demonstrated in a synthetic case study of aerobic respiration and denitrification in the saturated zone using a three-dimensional steady-state groundwater flow model combined with the simplified reactive transport approach.

  18. Subscales of the Barratt Impulsiveness Scale differentially relate to the Big Five factors of personality. (United States)

    Lange, Florian; Wagner, Adina; Müller, Astrid; Eggert, Frank


    The place of impulsiveness in multidimensional personality frameworks is still unclear. In particular, no consensus has yet been reached with regard to the relation of impulsiveness to Neuroticism and Extraversion. We aim to contribute to a clearer understanding of these relationships by accounting for the multidimensional structure of impulsiveness. In three independent studies, we related the subscales of the Barratt Impulsiveness Scale (BIS) to the Big Five factors of personality. Study 1 investigated the associations between the BIS subscales and the Big Five factors as measured by the NEO Five-Factor Inventory (NEO-FFI) in a student sample (N = 113). Selective positive correlations emerged between motor impulsiveness and Extraversion and between attentional impulsiveness and Neuroticism. This pattern of results was replicated in Study 2 (N = 132) using a 10-item short version of the Big Five Inventory. In Study 3, we analyzed BIS and NEO-FFI data obtained from a sample of patients with pathological buying (N = 68). In these patients, the relationship between motor impulsiveness and Extraversion was significantly weakened when compared to the non-clinical samples. At the same time, the relationship between attentional impulsiveness and Neuroticism was substantially stronger in the clinical sample. Our studies highlight the utility of the BIS subscales for clarifying the relationship between impulsiveness and the Big Five personality factors. We conclude that impulsiveness might occupy multiple places in multidimensional personality frameworks, which need to be specified to improve the interpretability of impulsiveness scales. © 2017 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

  19. Clay, Water, and Salt: Controls on the Permeability of Fine-Grained Sedimentary Rocks. (United States)

    Bourg, Ian C; Ajo-Franklin, Jonathan B


    The ability to predict the permeability of fine-grained soils, sediments, and sedimentary rocks is a fundamental challenge in the geosciences with potentially transformative implications in subsurface hydrology. In particular, fine-grained sedimentary rocks (shale, mudstone) constitute about two-thirds of the sedimentary rock mass and play important roles in three energy technologies: petroleum geology, geologic carbon sequestration, and radioactive waste management. The problem is a challenging one that requires understanding the properties of complex natural porous media on several length scales. One inherent length scale, referred to hereafter as the mesoscale, is associated with the assemblages of large grains of quartz, feldspar, and carbonates over distances of tens of micrometers. Its importance is highlighted by the existence of a threshold in the core scale mechanical properties and regional scale energy uses of shale formations at a clay content X clay ≈ 1/3, as predicted by an ideal packing model where a fine-grained clay matrix fills the gaps between the larger grains. A second important length scale, referred to hereafter as the nanoscale, is associated with the aggregation and swelling of clay particles (in particular, smectite clay minerals) over distances of tens of nanometers. Mesoscale phenomena that influence permeability are primarily mechanical and include, for example, the ability of contacts between large grains to prevent the compaction of the clay matrix. Nanoscale phenomena that influence permeability tend to be chemomechanical in nature, because they involve strong impacts of aqueous chemistry on clay swelling. The second length scale remains much less well characterized than the first, because of the inherent challenges associated with the study of strongly coupled nanoscale phenomena. Advanced models of the nanoscale properties of fine-grained media rely predominantly on the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, a mean field

  20. Effect of Items Direction (Positive or Negative) on the Factorial Construction and Criterion Related Validity in Likert Scale (United States)

    Naji Qasem, Mamun Ali; Ahmad Gul, Showkeen Bilal


    The study was conducted to know the effect of items direction (positive or negative) on the factorial construction and criterion related validity in Likert scale. The descriptive survey research method was used for the study and the sample consisted of 510 undergraduate students selected by used random sampling technique. A scale developed by…


    Directory of Open Access Journals (Sweden)

    Monica Pedrazza


    Full Text Available Research, all over the world, is starting to recognize the potential impact of physicians’ dissatisfaction and burnout on their productivity, that is, on their intent to leave the job, on their work ability, on the amount of sick leave days, on their intent to continue practicing, and last but not least, on the quality of the services provided, which is an essential part of the general medical care system. It was interest of the provincial medical board’s ethical committee to acquire information about physician’s work-related stress and dissatisfaction. The research group was committed to define the indicators of dissatisfaction and work-related stressors. Focus groups were carried out, 21 stressful experience’s indicators were identified; we developed an online questionnaire to assess the amount of perceived stress relating to each indicator at work (3070 physicians were contacted by e-mail; quantitative and qualitative data analysis were carried out. The grounded theory perspective was applied in order to assure the most reliable procedure to investigate the concepts’ structure of work-related stress. We tested the five dimensions' model of the stressful experience with a confirmatory factor analysis: Personal Costs; Decline in Public Image and Role Uncertainty; Physician's Responsibility toward hopelessly ill Patients; Relationship with Staff and Colleagues; Bureaucracy. We split the sample according to attachment style (secure and insecure -anxious and avoidant-. Results show the complex representation of physicians’ dissatisfaction at work also with references to the variable of individual difference of attachment security/insecurity. The discriminant validity of the scale was tested. The original contribution of this paper lies on the one hand in the qualitative in depth inductive analysis of physicians’ dissatisfaction starting from physicians’ perception, on the other hand, it represents the first attempt to analyze the

  2. Exploring Physicians' Dissatisfaction and Work-Related Stress: Development of the PhyDis Scale. (United States)

    Pedrazza, Monica; Berlanda, Sabrina; Trifiletti, Elena; Bressan, Franco


    Research, all over the world, is starting to recognize the potential impact of physicians' dissatisfaction and burnout on their productivity, that is, on their intent to leave the job, on their work ability, on the amount of sick leave days, on their intent to continue practicing, and last but not least, on the quality of the services provided, which is an essential part of the general medical care system. It was interest of the provincial medical board's ethical committee to acquire information about physician's work-related stress and dissatisfaction. The research group was committed to define the indicators of dissatisfaction and work-related stressors. Focus groups were carried out, 21 stressful experience's indicators were identified; we developed an online questionnaire to assess the amount of perceived stress relating to each indicator at work (3070 physicians were contacted by e-mail); quantitative and qualitative data analysis were carried out. The grounded theory perspective was applied in order to assure the most reliable procedure to investigate the concepts' structure of "work-related stress." We tested the five dimensions' model of the stressful experience with a confirmatory factor analysis: Personal Costs; Decline in Public Image and Role Uncertainty; Physician's Responsibility toward hopelessly ill Patients; Relationship with Staff and Colleagues; Bureaucracy. We split the sample according to attachment style (secure and insecure -anxious and avoidant-). Results show the complex representation of physicians' dissatisfaction at work also with references to the variable of individual difference of attachment security/insecurity. The discriminant validity of the scale was tested. The original contribution of this paper lies on the one hand in the qualitative in depth inductive analysis of physicians' dissatisfaction starting from physicians' perception, on the other hand, it represents the first attempt to analyze the physicians' dissatisfaction with

  3. Small-scale experiments with an analysis to evaluate the effect of tailored pulse loading on fracture and permeability. Final report for phase I, June 11, 1979-June 11, 1980

    Energy Technology Data Exchange (ETDEWEB)

    McHugh, S.


    To determine the applicability of the tailored pulse-loading technique to full-scale stimulation, a two-year program was conducted to examine the effects of pulse tailoring on fracture. Results of the field, laboratory, and calculational program demonstrate that: (1) the material and fracture properties derived from laboratory measurements can be used successfully in the NAG-FRAG calculational simulations to reproduce the main features of fracturing in the field; and (2) the fracture patterns produced in these experiments show a strong dependence on the borehole pressure pulse shape. The material and fracture properties will have a significant influence on the fracture patterns. Therefore, shale and tuff will have different optimum pulse shapes.

  4. Landscape permeability for large carnivores in Washington: a geographic information system weighted-distance and least-cost corridor assessment. (United States)

    Peter H. Singleton; William L. Gaines; John F. Lehmkuhl


    We conducted a regional-scale evaluation of landscape permeability for large carnivores in Washington and adjacent portions of British Columbia and Idaho. We developed geographic information system based landscape permeability models for wolves (Canis lupus), wolverine (Gulo gulo), lynx (Lynx canadensis),...

  5. Responsiveness of the Early Childhood Oral Health Impact Scale (ECOHIS) is related to dental treatment complexity. (United States)

    Novaes, Tatiane F; Pontes, Laura Regina A; Freitas, Julia G; Acosta, Carolina P; Andrade, Katia Cristina E; Guedes, Renata S; Ardenghi, Thiago M; Imparato, José Carlos P; Braga, Mariana M; Raggio, Daniela P; Mendes, Fausto M


    The responsiveness of the Early Childhood Oral Health Impact Scale (ECOHIS) has varied greatly across studies; hence, we hypothesized that this discrepancy could be related to the complexity of dental treatment received. Thus, we aimed to evaluate the responsiveness of the ECOHIS to changes in oral health-related quality of life (OHRQoL) following dental treatments of varying complexity in preschool children. Preschool children aged 3 to 6 years were selected; their parents responded to the ECOHIS at baseline. The parents responded to the ECOHIS again and a global transition question 30 days after the children were treated. The type of treatment received by the children was categorized according to complexity, as follows: 1) non-operative treatment only, 2) restorative treatment, and 3) endodontic treatment and/or tooth extraction. Change scores and effect sizes (ES) were calculated for total scores, as well as considering the different treatment types and global transition question responses. Of the 152 children who completed the study, the ECOHIS yielded large ES for total scores (0.89). The children showed increasing ES values associated with better perception of improvement, assessed by the global transition question. The magnitude of ES after treatment was related to treatment complexity (0.53, 0.92 and 1.43, for children who received non-operative treatment only, restorative treatment, and endodontic treatment and/or tooth extraction, respectively). Parents whose children required more complex dental treatment are more likely to perceive treatment-related changes to OHRQoL assessed with the ECOHIS.

  6. A Research on Permeability Concept at an Urban Pedestrian Shopping Street: A Case of Trabzon Kunduracilar Street

    Directory of Open Access Journals (Sweden)

    Aysel Yavuz


    Full Text Available This research in which components of permeability concept is tried to be set forth, presents the results of a field study conducted on a pedestrian-shopping street in Trabzon, a coastal city in the eastern Black Sea Region. The criteria affecting permeability are dealt with in physical, functional and perceptual properties. Accordingly, three hypotheses are proposed in this article. The study was a two-stage survey. The first survey is prepared to determine user preferences. With the second survey prepared in the light of the data obtained from the first one, characteristics defining the permeability concept were sought for. As a result, permeability level of a street is found to be closely related with the physical, functional and perceptual properties providing such permeability and, permeability is determined to be best provided by considering all the three properties together, and new perspective to the concept of permeability is brought with this model.

  7. Gas permeability of cement based materials; Etude de la permeabilite au gaz des materiaux cimentaires

    Energy Technology Data Exchange (ETDEWEB)

    Galle, Ch.; Pin, M. [CEA Saclay, Dept. d' Entreposage et de Stockage des Dechets (DCC/DESD/SESD), 91 - Gif-sur-Yvette (France); Daian, J.F. [Universite Joseph-Fourier, Grenoble I, (INPG/CNRS/IRD), 38 (France)


    The study of the permeability of cement based materials is an important issue for their transport properties, which are good indicators of their durability. Studies were undertaken to acquire experimental data and to model the gas permeability of cement based materials. Among many parameters like cement type, water-cement ratio (w/c), curing, etc, the degree of water saturation and microstructural properties are the two main parameters controlling the ability of such type of materials to transport gas. It is well known that the higher the water saturation, the lower the gas permeability. Under pressure, gas will be also transported through the biggest pore accesses. It must be emphasized that the w/c ratio is the fundamental parameter for cement based materials. This ratio controls the hydration process and hence the material porosity. Gas permeability was calculated with Darcy law as modified by the Hagen-Poiseuille formula (1). Various materials were investigated: pure cement pastes prepared with different types of cement (CEM I-OPC, CEM V-BFS-PFA) and various w/c ratios, and industrial concretes. After curing, the samples were stored under controlled relative humidity conditions using saline solutions to reach a stable hydric state. N{sup 2} gas permeability tests were then performed with a Hassler apparatus. The microstructural properties of CEM I and CEM V materials are given in Figure 2. Examples of experimental results obtained with pure pastes are shown in Figure 3. A comparative example of paste and concrete data is provided in Figure 4. It was experimentally observed that gas permeability is extremely sensitive to material water saturation: up to five orders of magnitude of variation (between 10{sup -16} and 10{sup -21} m{sup 2} on average) for water saturations from a few % to 100%. The higher the w/c ratio, the higher the gas permeability. CEM I pastes are also less permeable than CEM V pastes. The higher total porosity effect of CEM V materials is not

  8. Factors Influencing Stormwater Mitigation in Permeable Pavement

    Directory of Open Access Journals (Sweden)

    Chun Yan Liu


    Full Text Available Permeable pavement (PP is used worldwide to mitigate surface runoff in urban areas. Various studies have examined the factors governing the hydrologic performance of PP. However, relatively little is known about the relative importance of these governing factors and the long-term hydrologic performance of PP. This study applied numerical models—calibrated and validated using existing experimental results—to simulate hundreds of event-based and two long-term rainfall scenarios for two designs of PP. Based on the event-based simulation results, rainfall intensity, rainfall volume, thickness of the storage layer and the hydraulic conductivity of the subgrade were identified as the most influential factors in PP runoff reduction. Over the long term, PP performed significantly better in a relatively drier climate (e.g., New York, reducing nearly 90% of runoff volume compared to 70% in a relatively wetter climate (e.g., Hong Kong. The two designs of PP examined performed differently, and the difference was more apparent in the relatively wetter climate. This study generated insights that will help the design and implementation of PP to mitigate stormwater worldwide.

  9. Probing galaxy growth through metallicity scaling relations over the past 12 Gyr of cosmic history (United States)

    Sanders, Ryan; MOSDEF team


    A primary goal of galaxy evolution studies is to understand the processes governing the growth of the baryonic content of galaxies over cosmic history. Observations of galaxy metallicity scaling relations and their evolution with redshift, in combination with chemical evolution models, provide unique insight into the interplay between star formation, gas accretion, and feedback/outflows. I present measurements of the stellar mass-gas phase metallicity relation and its evolution over the past 12 Gyr from z~0 to z~3.5, utilizing data from the Mosfire Deep Evolution Field survey that uniquely provides rest-frame optical spectra of >1000 uniformly-selected galaxies at z=1.3-3.8. We find evolution towards lower metallicity at fixed stellar mass with increasing redshift that is consistent with current cosmological simulations including chemical evolution, with a large evolution of ~0.3 dex from z~0 to z~2.5 and minor evolution of 2, and discuss the potential of current and next-generation observational facilities to obtain statistical auroral-line samples at high redshifts.

  10. Large-scale investigation of human TF-miRNA relations based on coexpression profiles. (United States)

    Chien, Chia-Hung; Chiang-Hsieh, Yi-Fan; Tsou, Ann-Ping; Weng, Shun-Long; Chang, Wen-Chi; Huang, Hsien-Da


    Noncoding, endogenous microRNAs (miRNAs) are fairly well known for regulating gene expression rather than protein coding. Dysregulation of miRNA gene, either upregulated or downregulated, may lead to severe diseases or oncogenesis, especially when the miRNA disorder involves significant bioreactions or pathways. Thus, how miRNA genes are transcriptionally regulated has been highlighted as well as target recognition in recent years. In this study, a large-scale investigation of novel cis- and trans-elements was undertaken to further determine TF-miRNA regulatory relations, which are necessary to unravel the transcriptional regulation of miRNA genes. Based on miRNA and annotated gene expression profiles, the term "coTFBS" was introduced to detect common transcription factors and the corresponding binding sites within the promoter regions of each miRNA and its coexpressed annotated genes. The computational pipeline was successfully established to filter redundancy due to short sequence motifs for TFBS pattern search. Eventually, we identified more convinced TF-miRNA regulatory relations for 225 human miRNAs. This valuable information is helpful in understanding miRNA functions and provides knowledge to evaluate the therapeutic potential in clinical research. Once most expression profiles of miRNAs in the latest database are completed, TF candidates of more miRNAs can be explored by this filtering approach in the future.

  11. Aging on a different scale – chronological versus pathology-related aging (United States)

    Melis, Joost P.M.; Jonker, Martijs J.; Vijg, Jan; Hoeijmakers, Jan H.J.; Breit, Timo M.; van Steeg, Harry


    In the next decades the elderly population will increase dramatically, demanding appropriate solutions in health care and aging research focusing on healthy aging to prevent high burdens and costs in health care. For this, research targeting tissue-specific and individual aging is paramount to make the necessary progression in aging research. In a recently published study we have attempted to make a step interpreting aging data on chronological as well as pathological scale. For this, we sampled five major tissues at regular time intervals during the entire C57BL/6J murine lifespan from a controlled in vivo aging study, measured the whole transcriptome and incorporated temporal as well as physical health aspects into the analyses. In total, we used 18 different age-related pathological parameters and transcriptomic profiles of liver, kidney, spleen, lung and brain and created a database that can now be used for a broad systems biology approach. In our study, we focused on the dynamics of biological processes during chronological aging and the comparison between chronological and pathology-related aging. PMID:24131799

  12. Aging on a different scale--chronological versus pathology-related aging. (United States)

    Melis, Joost P M; Jonker, Martijs J; Vijg, Jan; Hoeijmakers, Jan H J; Breit, Timo M; van Steeg, Harry


    In the next decades the elderly population will increase dramatically, demanding appropriate solutions in health care and aging research focusing on healthy aging to prevent high burdens and costs in health care. For this, research targeting tissue-specific and individual aging is paramount to make the necessary progression in aging research. In a recently published study we have attempted to make a step interpreting aging data on chronological as well as pathological scale. For this, we sampled five major tissues at regular time intervals during the entire C57BL/6J murine lifespan from a controlled in vivo aging study, measured the whole transcriptome and incorporated temporal as well as physical health aspects into the analyses. In total, we used 18 different age-related pathological parameters and transcriptomic profiles of liver, kidney, spleen, lung and brain and created a database that can now be used for a broad systems biology approach. In our study, we focused on the dynamics of biological processes during chronological aging and the comparison between chronological and pathology-related aging.

  13. Exploring the construct validity of the social cognition and object relations scale in a clinical sample. (United States)

    Stein, Michelle B; Slavin-Mulford, Jenelle; Sinclair, S Justin; Siefert, Caleb J; Blais, Mark A


    The Social Cognition and Object Relations Scale-Global rating method (SCORS-G; Stein, Hilsenroth, Slavin-Mulford, & Pinsker, 2011; Westen, 1995) measures the quality of object relations in narrative material. This study employed a multimethod approach to explore the structure and construct validity of the SCORS-G. The Thematic Apperception Test (TAT; Murray, 1943) was administered to 59 patients referred for psychological assessment at a large Northeastern U.S. hospital. The resulting 301 TAT narratives were rated using the SCORS-G method. The 8 SCORS variables were found to have high interrater reliability and good internal consistency. Principal components analysis revealed a 3-component solution with components tapping emotions/affect regulation in relationships, self-image, and aspects of cognition. Next, the construct validity of the SCORS-G components was explored using measures of intellectual and executive functioning, psychopathology, and normal personality. The 3 SCORS-G components showed unique and theoretically meaningful relationships across these broad and diverse psychological measures. This study demonstrates the value of using a standardized scoring method, like the SCORS-G, to reveal the rich and complex nature of narrative material.

  14. Gyroid Nanoporous Membranes with Tunable Permeability

    DEFF Research Database (Denmark)

    Li, Li; Schulte, Lars; Clausen, Lydia D.


    Understanding the relevant permeability properties of ultrafiltration membranes is facilitated by using materials and procedures that allow a high degree of control on morphology and chemical composition. Here we present the first study on diffusion permeability through gyroid nanoporous cross-linked...

  15. Alterations in Intestinal Permeability After Thermal Injury, (United States)


    Permeability After Burns-LeVoyer et al R wthe Arrihtv.of Su~gy8 4• u’y 1992, Voue 127 Copright 1992. Akn • Med/kaf Awoctahbn Patlenbs Controls 4. (n-=1...may have a role in the tinal tract is enteral nutrition . I was wondering if by any chance development of increased permeability, then we can evaluate

  16. Intercomparison on measurement of water vapour permeability

    DEFF Research Database (Denmark)

    Hansen, Kurt Kielsgaard

    Three different materials are tested - hard woodfibre board - damp proof course - underlay for roofing The water vapour permeability has been measured according to EN ISO 12572 (2001).......Three different materials are tested - hard woodfibre board - damp proof course - underlay for roofing The water vapour permeability has been measured according to EN ISO 12572 (2001)....

  17. A Negative Permeability Material at Red Light

    DEFF Research Database (Denmark)

    Yuan, Hsiao-Kuan; Chettiar, Uday K.; Cai, Wenshan


    A negative permeability in a periodic array of pairs of thin silver strips is demonstrated experimentally for two distinct samples. The effect of the strip surface roughness on negative permeability is evaluated. The first sample, Sample A, is fabricated of thinner strips with a root mean square ...

  18. Crustal permeability: Introduction to the special issue (United States)

    Ingebritsen, Steven E.; Gleeson, Tom


    The topic of crustal permeability is of broad interest in light of the controlling effect of permeability on diverse geologic processes and also timely in light of the practical challenges associated with emerging technologies such as hydraulic fracturing for oil and gas production (‘fracking’), enhanced geothermal systems, and geologic carbon sequestration. This special issue of Geofluids is also motivated by the historical dichotomy between the hydrogeologic concept of permeability as a static material property that exerts control on fluid flow and the perspective of economic geologists, geophysicists, and crustal petrologists who have long recognized permeability as a dynamic parameter that changes in response to tectonism, fluid production, and geochemical reactions. Issues associated with fracking, enhanced geothermal systems, and geologic carbon sequestration have already begun to promote a constructive dialog between the static and dynamic views of permeability, and here we have made a conscious effort to include both viewpoints. This special issue also focuses on the quantification of permeability, encompassing both direct measurement of permeability in the uppermost crust and inferential permeability estimates, mainly for the deeper crust.

  19. Adaptive Methods for Permeability Estimation and Smart Well Management

    Energy Technology Data Exchange (ETDEWEB)

    Lien, Martha Oekland


    The main focus of this thesis is on adaptive regularization methods. We consider two different applications, the inverse problem of absolute permeability estimation and the optimal control problem of estimating smart well management. Reliable estimates of absolute permeability are crucial in order to develop a mathematical description of an oil reservoir. Due to the nature of most oil reservoirs, mainly indirect measurements are available. In this work, dynamic production data from wells are considered. More specifically, we have investigated into the resolution power of pressure data for permeability estimation. The inversion of production data into permeability estimates constitutes a severely ill-posed problem. Hence, regularization techniques are required. In this work, deterministic regularization based on adaptive zonation is considered, i.e. a solution approach with adaptive multiscale estimation in conjunction with level set estimation is developed for coarse scale permeability estimation. A good mathematical reservoir model is a valuable tool for future production planning. Recent developments within well technology have given us smart wells, which yield increased flexibility in the reservoir management. In this work, we investigate into the problem of finding the optimal smart well management by means of hierarchical regularization techniques based on multiscale parameterization and refinement indicators. The thesis is divided into two main parts, where Part I gives a theoretical background for a collection of research papers that has been written by the candidate in collaboration with others. These constitutes the most important part of the thesis, and are presented in Part II. A brief outline of the thesis follows below. Numerical aspects concerning calculations of derivatives will also be discussed. Based on the introduction to regularization given in Chapter 2, methods for multiscale zonation, i.e. adaptive multiscale estimation and refinement

  20. Wave transmission over permeable submerged breakwaters; Transmision del oleaje en rompeolas sumergidos permeables

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-y-Zurvia-Flores, Jaime Roberto; Fragoso-Sandoval, Lucio [Instituto Politecnico Nacional(Mexico)


    The permeable submerged breakwaters represent a coastal protection alternative, where some degree of wave energy transmission is acceptable. Such would be the case of tourist beach protection in Mexico. In previous researches, like those performed by D'Angremond et al. (1996), Seabrook and Hall (1998), and Briganti et al. (2003), the empirical formulas developed, give only some limited information over the spatial distribution of wave energy over the structure. Therefore, a decision was made to conduct a study on a reduced physical model of a permeable submerged breakwater based on the results presented by those researchers and with possible applications. Therefore this paper presents the development of a study of wave transmission over permeable submerged breakwaters performed in a reduced physical model of different sections of a submerged rockfill breakwater of the trapezoidal type. This was done in a narrow wave flume with a hydraulic irregular wave generator controlled by a computer that was used to generate and to reproduce different types of irregular waves to be used in the tests. It also has a wave meter with four sensors, and they are connected to a computer in order to process the wave data. The main objective of the study was to determine in an experimental way the influence of the several parameters of submerged breakwater over the wave transmission coefficient. Our experimental results were comparable to those obtained by D'Angremond et al. (1996) and Seabrook and Hall (1998). The results show that the sumerged breakwater parameters of most influence over the wave transmission coefficient were relative submergence and the relative width crest of the sumerged breakwater, and that the formula by Seabrook and Hall correlates best with our results. [Spanish] Los rompeolas sumergidos permeables representan actualmente una alternativa de proteccion de costas, donde un cierto grado de transmision de energia del oleaje es aceptable, como seria el

  1. Colloid transport in dual-permeability media. (United States)

    Leij, Feike J; Bradford, Scott A


    It has been widely reported that colloids can travel faster and over longer distances in natural structured porous media than in uniform structureless media used in laboratory studies. The presence of preferential pathways for colloids in the subsurface environment is of concern because of the increased risks for disease caused by microorganisms and colloid-associated contaminants. This study presents a model for colloid transport in dual-permeability media that includes reversible and irreversible retention of colloids and first-order exchange between the aqueous phases of the two regions. The model may also be used to describe transport of other reactive solutes in dual-permeability media. Analytical solutions for colloid concentrations in aqueous and solid phases were obtained using Laplace transformation and matrix decomposition. The solutions proved convenient to assess the effect of model parameters on the colloid distribution. The analytical model was used to describe effluent concentrations for a bromide tracer and 3.2- or 1-μm-colloids that were observed after transport through a composite 10-cm long porous medium made up of a cylindrical lens or core of sand and a surrounding matrix with sand of a different grain size. The tracer data were described very well and realistic estimates were obtained for the pore-water velocity in the two flow domains. An accurate description was also achieved for most colloid breakthrough curves. Dispersivity and retention parameters were typically greater for the larger 3.2-μm-colloids while both reversible and irreversible retention rates tended to be higher for the finer sands than the coarser sand. The relatively small sample size and the complex flow pattern in the composite medium made it difficult to reach definitive conclusions regarding transport parameters for colloid transport. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Scaling of Primate Forearm Muscle Architecture as It Relates to Locomotion and Posture. (United States)

    Leischner, Carissa L; Crouch, Michael; Allen, Kari L; Marchi, Damiano; Pastor, Francisco; Hartstone-Rose, Adam


    It has been previously proposed that distal humerus morphology may reflect the locomotor pattern and substrate preferred by different primates. However, relationships between these behaviors and the morphological capabilities of muscles originating on these osteological structures have not been fully explored. Here, we present data about forearm muscle architecture in a sample of 44 primate species (N = 55 specimens): 9 strepsirrhines, 15 platyrrhines, and 20 catarrhines. The sample includes all major locomotor and substrate use groups. We isolated each antebrachial muscle and categorized them into functional groups: wrist and digital extensors and flexors, antebrachial mm. that do not cross the wrist, and functional combinations thereof. Muscle mass, physiological cross-sectional area (PCSA), reduced PCSA (RPCSA), and fiber length (FL) are examined in the context of higher taxonomic group, as well as locomotor/postural and substrate preferences. Results show that muscle masses, PCSA, and RPCSA scale with positive allometry while FL scales with isometry indicating that larger primates have relatively stronger, but neither faster nor more flexible, forearms across the sample. When accounting for variation in body size, we found no statistically significant difference in architecture among higher taxonomic groups or locomotor/postural groups. However, we found that arboreal primates have significantly greater FL than terrestrial ones, suggesting that these species are adapted for greater speed and/or flexibility in the trees. These data may affect our interpretation of the mechanisms for variation in humeral morphology and provide information for refining biomechanical models of joint stress and movement in extant and fossil primates. Anat Rec, 301:484-495, 2018. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

  3. Microorganism Removal in Permeable Pavement Parking Lots ... (United States)

    Three types of permeable pavements (pervious concrete, permeable interlocking concrete pavers, and porous asphalt) were monitored at the Edison Environmental Center in Edison, New Jersey for indicator organisms such as fecal coliform, enterococci, and E. coli. Results showed that porous asphalt had much lower concentration in monitored infiltrate compared to pervious concrete and permeable interlocking concrete pavers. Concentrations of monitored organisms in infiltrate from porous asphalt were consistently below the bathing water quality standard. Fecal coliform and enterococci exceeded bathing water quality standards more than 72% and 34% of the time for permeable interlocking concrete pavers and pervious concrete, respectively. Purpose is to evaluate the performance of permeable pavement in removing indicator organisms from infiltrating stormwater runoff.

  4. Modelling of water permeability in cementitious materials

    DEFF Research Database (Denmark)

    Guang, Ye; Lura, Pietro; van Breugel, K.


    This paper presents a network model to predict the permeability of cement paste from a numerical simulation of its microstructure. Based on a linked list pore network structure, the effective hydraulic conductivity is estimated and the fluid flow is calculated according to the Hagen-Poiseuille law....... The pressure gradient at all nodes is calculated with the Gauss elimination method and the absolute permeability of the pore network is calculated directly from Darcy's law. Finally, the permeability model is validated by comparison with direct water permeability measurements. According to this model...... and by the connectivity of the pore structure, regardless of w/c ratio and curing age. The permeability of cement pastes could be predicted reasonably well when a minimum particle size 1 mu m was chosen for the cement....

  5. Vascular permeability in cerebral cavernous malformations

    DEFF Research Database (Denmark)

    Mikati, Abdul G; Khanna, Omaditya; Zhang, Lingjiao


    -controlled observational study investigated whether the brains of human subjects with familial CCM show vascular hyperpermeability by dynamic contrast-enhanced quantitative perfusion magnetic resonance imaging, in comparison with CCM cases without familial disease, and whether lesional or brain vascular permeability...... vascular hyperpermeability in humans with an autosomal dominant disease, as predicted mechanistically. Brain permeability, more than lesion permeability, may serve as a biomarker of CCM disease activity, and help calibrate potential drug therapy....... correlates with CCM disease activity. Permeability in white matter far (WMF) from lesions was significantly greater in familial than in sporadic cases, but was similar in CCM lesions. Permeability in WMF increased with age in sporadic patients, but not in familial cases. Patients with more aggressive...

  6. Permeability measurement and control for epoxy composites (United States)

    Chang, Tsun-Hsu; Tsai, Cheng-Hung; Wong, Wei-Syuan; Chen, Yen-Ren; Chao, Hsien-Wen


    The coupling of the electric and magnetic fields leads to a strong interplay in materials' permittivity and permeability. Here, we proposed a specially designed cavity, called the mu cavity. The mu cavity, consisting of a mushroom structure inside a cylindrical resonator, is exclusively sensitive to permeability, but not to permittivity. It decouples materials' electromagnetic properties and allows an accurate measurement of the permeability. With the help of an epsilon cavity, these two cavities jointly determine the complex permeability and permittivity of the materials at microwave frequencies. Homemade epoxy-based composite materials were prepared and tested. Measurement and manipulation of the permeability and permittivity of the epoxy composites will be shown. The results will be compared with the effective medium theories.

  7. Redox-active media for permeable reactive barriers

    Energy Technology Data Exchange (ETDEWEB)

    Sivavec, T.M. [General Electric Corp. Research and Development Center, Schenectady, NY (United States); Mackenzie, P.D.; Horney, D.P.; Baghel, S.S.


    In this paper, three classes of redox-active media are described and evaluated in terms of their long-term effectiveness in treating TCE-contaminated groundwater in permeable reactive zones. Zero-valent iron, in the form of recycled cast iron filings, the first class, has received considerable attention as a reactive media and has been used in about a dozen pilot- and full-scale subsurface wall installations. Criteria used in selecting commercial sources of granular iron, will be discussed. Two other classes of redox-active media that have not yet seen wide use in pilot- or full-scale installations will also be described: Fe(II) minerals and bimetallic systems. Fe(II) minerals, including magnetite (Fe{sub 3}O{sub 4}), and ferrous sulfide (troilite, FeS), are redox-active and afford TCE reduction rates and product distributions that suggest that they react via a reductive mechanism similar to that which operates in the FeO system. Fe(II) species within the passive oxide layer coating the iron metal may act as electron transfer mediators, with FeO serving as the bulk reductant. Bimetallic systems, the third class of redox-active media, are commonly prepared by plating a second metal onto zero-valent iron (e.g., Ni/Fe and Pd/Fe) and have been shown to accelerate solvent degradation rates relative to untreated iron metal. The long-term effectiveness of this approach, however, has not yet been determined in groundwater treatability tests. The results of a Ni-plated iron column study using site groundwater indicate that a change in reduction mechanism (to catalytic dehydrohalogenation/hydrogenation) accounts for the observed rate enhancement. A significant loss in media reactivity was observed over time, attributable to Ni catalyst deactivation or poisoning. Zero-valent iron systems have not shown similar losses in reactivity in long-term laboratory, pilot or field investigations.

  8. New well pattern optimization methodology in mature low-permeability anisotropic reservoirs (United States)

    Qin, Jiazheng; Liu, Yuetian; Feng, Yueli; Ding, Yao; Liu, Liu; He, Youwei


    In China, lots of well patterns were designed before people knew the principal permeability direction in low-permeability anisotropic reservoirs. After several years’ production, it turns out that well line direction is unparallel with principal permeability direction. However, traditional well location optimization methods (in terms of the objective function such as net present value and/or ultimate recovery) are inapplicable, since wells are not free to move around in a mature oilfield. Thus, the well pattern optimization (WPO) of mature low-permeability anisotropic reservoirs is a significant but challenging task, since the original well pattern (WP) will be distorted and reconstructed due to permeability anisotropy. In this paper, we investigate the destruction and reconstruction of WP when the principal permeability direction and well line direction are unparallel. A new methodology was developed to quantitatively optimize the well locations of mature large-scale WP through a WPO algorithm on the basis of coordinate transformation (i.e. rotating and stretching). For a mature oilfield, large-scale WP has settled, so it is not economically viable to carry out further infill drilling. This paper circumvents this difficulty by combining the WPO algorithm with the well status (open or shut-in) and schedule adjustment. Finally, this methodology is applied to an example. Cumulative oil production rates of the optimized WP are higher, and water-cut is lower, which highlights the potential of the WPO methodology application in mature large-scale field development projects.

  9. Thermal treatment of low permeability soils using electrical resistance heating

    Energy Technology Data Exchange (ETDEWEB)

    Udell, K.S. [Univ. of California, Berkeley, CA (United States)


    The acceleration of recovery rates of second phase liquid contaminants from the subsurface during gas or water pumping operations is realized by increasing the soil and ground water temperature. Electrical heating with AC current is one method of increasing the soil and groundwater temperature and has particular applicability to low permeability soils. Several mechanisms have been identified that account for the enhanced removal of the contaminants during electrical heating. These are vaporization of liquid contaminants with low boiling points, temperature-enhanced evaporation rates of semi-volatile components, and removal of residual contaminants by the boiling of residual water. Field scale studies of electrical heating and fluid extraction show the effectiveness of this technique and its applicability to contaminants found both above and below the water table and within low permeability soils. 10 refs., 8 figs.

  10. Simultaneous assessment of vessel size index, relative blood volume, and vessel permeability in a mouse brain tumor model using a combined spin echo gradient echo echo-planar imaging sequence and viable tumor analysis. (United States)

    Kording, Fabian; Weidensteiner, Claudia; Zwick, Stefan; Osterberg, Nadja; Weyerbrock, Astrid; Staszewski, Ori; von Elverfeldt, Dominik; Reichardt, Wilfried


    Combining multiple imaging biomarkers in one magnetic resonance imaging (MRI) session would be beneficial to gain more data pertaining to tumor vasculature under therapy. Therefore, simultaneous measurement of perfusion, permeability, and vessel size imaging (VSI) using a gradient echo spin echo (GE-SE) sequence with injection of a clinically approved gadolinium (Gd)-based contrast agent was assessed in an orthotopic glioma model. A combined spin echo gradient echo echo-planar imaging sequence was implemented using a single contrast agent Gd diethylenetriaminepentaacetic acid (Gd-DTPA). This sequence was tested in a mouse brain tumor model (U87_MG), also under treatment with an antiangiogenic agent (bevacizumab). T2 maps and the apparent diffusion coefficient (ADC) were used to differentiate regions of cell death and viable tumor tissue. In viable tumor tissue regional blood volume was 5.7 ± 0.6% in controls and 5.2 ± 0.3% in treated mice. Vessel size was 18.1 ± 2.4 μm in controls and 12.8 ± 2.0 μm in treated mice, which correlated with results from immunohistochemistry. Permeability (K(trans) ) was close to zero in treated viable tumor tissue and 0.062 ± 0.024 min(-1) in controls. Our MRI method allows simultaneous assessment of several physiological and morphological parameters and extraction of MRI biomarkers for vasculature. These could be used for treatment monitoring of novel therapeutic agents such as antiangiogenic drugs. © 2014 Wiley Periodicals, Inc.

  11. Evaluation of treatment related fear using a newly developed fear scale for children: "Fear assessment picture scale" and its association with physiological response

    Directory of Open Access Journals (Sweden)

    Nishidha Tiwari


    Full Text Available Introduction: Dental treatment is usually a poignant phenomenon for children. Projective scales are preferred over psychometric scales to recognize it, and to obtain the self-report from children. Aims: The aims were to evaluate treatment related fear using a newly developed fear scale for children, fear assessment picture scale (FAPS, and anxiety with colored version of modified facial affective scale (MFAS - three faces along with physiologic responses (pulse rate and oxygen saturation obtained by pulse oximeter before and during pulpectomy procedure. Settings and Design: Total, 60 children of age 6-8 years who were visiting the dental hospital for the first time and needed pulpectomy treatment were selected. Children selected were of sound physical, physiological, and mental condition. Two projective scales were used; one to assess fear - FAPS and to assess anxiety - colored version of MFAS - three faces. These were co-related with the physiological responses (oxygen saturation and pulse rate of children obtained by pulse oximeter before and during the pulpectomy procedure. Statistical Analysis Used: Shapiro-Wilk test, McNemar′s test, Wilcoxon signed ranks test, Kruskal-Wallis test, Mann-Whitney test were applied in the study. Results: The physiological responses showed association with FAPS and MFAS though not significant. However, oxygen saturation with MFAS showed a significant change between "no anxiety" and "some anxiety" as quantified by Kruskal-Wallis test value 6.287, P = 0.043 (<0.05 before pulpectomy procedure. Conclusions: The FAPS can prove to be a pragmatic tool in spotting the fear among young children. This test is easy and fast to apply on children and reduces the chair-side time.

  12. Validation of the Mothers Object Relations scales in 2-4 year old children and comparison with the Child-Parent Relationship Scale. (United States)

    Simkiss, Douglas E; MacCallum, Fiona; Fan, Emma E Y; Oates, John M; Kimani, Peter K; Stewart-Brown, Sarah


    The quality of the parent-child relationship has an important effect on a wide range of child outcomes. The evaluation of interventions to promote healthy parenting and family relationships is dependent on outcome measures which can quantify the quality of parent-child relationships. Between the Mothers' Object Relations - Short Form (MORS-SF) scale for babies and the Child-parent Relationship Scale (C-PRS) there is an age gap where no validated scales are available. We report the development and testing of an adaptation of the MORS-SF; the MORS (Child) scale and its use in children from the age of 2 years to 4 years. This scale aims to capture the nature of the parent-child relationship in a form which is short enough to be used in population surveys and intervention evaluations. Construct and criterion validity, item salience and internal consistency were assessed in a sample of 166 parents of children aged 2-4 years old and compared with that of the C-PRS. The performance of the MORS (Child) as part of a composite measure with the HOME inventory was compared with that of the C-PRS using data collected in a randomised controlled trial and the national evaluation of Sure Start. MORS (Child) performed well in children aged 2-4 with high construct and criterion validity, item salience and internal consistency. One item in the C-PRS failed to load on either subscale and parents found this scale slightly more difficult to complete than the MORS (Child). The two measures performed very similarly in a factor analysis with the HOME inventory producing almost identical loadings. Adapting the MORS-SF for children aged 2-4 years old produces a scale to assess parent-child relationships that is easy to use and outperforms the more commonly used C-PRS in several respects.

  13. Gas permeability in polymer- and surfactant-stabilized bubble films. (United States)

    Andreatta, Gaëlle; Lee, Lay-Theng; Lee, Fuk Kay; Benattar, Jean-Jacques


    The gas permeabilities of thin liquid films stabilized by poly(N-isopropylacrylamide) (PNIPAM) and PNIPAM-SDS (sodium dodecyl sulfate) mixtures are studied using the "diminishing bubble" method. The method consists of forming a microbubble on the surface of the polymer solution and measuring the shrinking rates of the bubble and the bubble film as the gas diffuses from the interior to the exterior of the bubble. PNIPAM-stabilized films exhibit variable thicknesses and homogeneities. Interestingly, despite these variable features, the gas permeability of the film is determined principally by the structure of the adsorbed polymer layer that provides an efficient gas barrier with a value of gas permeability coefficient that is comparable to that of an SDS Newton black film. In the presence of SDS, both the film homogeneity and the gas permeability coefficient increase. These changes are related to interactions of PNIPAM with SDS in the solution and at the interface, where coadsorption of the two species forms mixed layers that are stable but that are more porous to gas transfer. The mixed PNIPAM-SDS layers, studied previously for a single water-air interface by neutron reflectivity, are further characterized here in a vertical free-draining film using X-ray reflectivity.

  14. Trench infiltration for managed aquifer recharge to permeable bedrock (United States)

    Heilweil, V.M.; Watt, D.E.


    Managed aquifer recharge to permeable bedrock is increasingly being utilized to enhance resources and maintain sustainable groundwater development practices. One such target is the Navajo Sandstone, an extensive regional aquifer located throughout the Colorado Plateau of the western United States. Spreading-basin and bank-filtration projects along the sandstone outcrop's western edge in southwestern Utah have recently been implemented to meet growth-related water demands. This paper reports on a new cost-effective surface-infiltration technique utilizing trenches for enhancing managed aquifer recharge to permeable bedrock. A 48-day infiltration trench experiment on outcropping Navajo Sandstone was conducted to evaluate this alternative surface-spreading artificial recharge method. Final infiltration rates through the bottom of the trench were about 0.5 m/day. These infiltration rates were an order of magnitude higher than rates from a previous surface-spreading experiment at the same site. The higher rates were likely caused by a combination of factors including the removal of lower permeability soil and surficial caliche deposits, access to open vertical sandstone fractures, a reduction in physical clogging associated with silt and biofilm layers, minimizing viscosity effects by maintaining isothermal conditions, minimizing chemical clogging caused by carbonate mineral precipitation associated with algal photosynthesis, and diminished gas clogging associated with trapped air and biogenic gases. This pilot study illustrates the viability of trench infiltration for enhancing surface spreading of managed aquifer recharge to permeable bedrock. ?? 2010.

  15. Pulmonary epithelial permeability in rats with bleomycin-induced pneumonitis

    Energy Technology Data Exchange (ETDEWEB)

    Anazawa, Yoshiki; Isawa, Toyoharu; Teshima, Takeo; Miki, Makoto; Motomiya, Masakichi (Tohoku Univ., Sendai (Japan). Research Inst. for Tuberculosis and Cancer)


    This study was performed to investigate the mechanism by which [sup 99m]Tc-DTPA molecules pass through the pulmonary epithelium following inhalation of [sup 99m]Tc-DTPA aerosol. Interstitial pneumonitis was induced in 6-week-old male rats by instilling 1 mg/kg of bleomycin into the trachea. Disappearance of radioactivity from the lungs was measured with a gamma camera every 2 weeks to estimate pulmonary epithelial permeability, and light- and electron-microscopic histopathologic examinations were performed at the same intervals. There was a statistically significant increase in the pulmonary epithelial permeability at 2 weeks after the instillation of bleomycin. However, subsecquent changes in pulmonary epithelial permeability were not uniform; some animals showed recovery and some showed further increase and/or partial recovery. Microscopically, increase in the capillary bed, round cell infiltration, and widening of the interstitial space were observed in addition to the presence of macrophages in the alveolar spaces at 2 weeks. Electron microscopic examination revealed vacuolization, thinning and detachment of the alveolar epithelium, and denudation of the basement membrane. Prominent fibrosis, honeycombing, thinning of the pulmonary epithelium, and increase in collagen fibers were observed after 18 weeks. We consider that vacuolization, thinning, and detachment of the pulmonary epithelium and denudation of the basement membrane are related to the increase in pulmonary epithelial permeability in bleomycin-induced interstitial pneumonitis. (author).

  16. LOFAR MSSS: The scaling relation between AGN cavity power and radio luminosity at low radio frequencies (United States)

    Kokotanekov, G.; Wise, M.; Heald, G. H.; McKean, J. P.; Bîrzan, L.; Rafferty, D. A.; Godfrey, L. E. H.; de Vries, M.; Intema, H. T.; Broderick, J. W.; Hardcastle, M. J.; Bonafede, A.; Clarke, A. O.; van Weeren, R. J.; Röttgering, H. J. A.; Pizzo, R.; Iacobelli, M.; Orrú, E.; Shulevski, A.; Riseley, C. J.; Breton, R. P.; Nikiel-Wroczyński, B.; Sridhar, S. S.; Stewart, A. J.; Rowlinson, A.; van der Horst, A. J.; Harwood, J. J.; Gürkan, G.; Carbone, D.; Pandey-Pommier, M.; Tasse, C.; Scaife, A. M. M.; Pratley, L.; Ferrari, C.; Croston, J. H.; Pandey, V. N.; Jurusik, W.; Mulcahy, D. D.


    We present a new analysis of the widely used relation between cavity power and radio luminosity in clusters of galaxies with evidence for strong AGN feedback. We studied the correlation at low radio frequencies using two new surveys - the first alternative data release of the TIFR GMRT Sky Survey (TGSS ADR1) at 148 MHz and LOFAR's firstall-sky survey, the Multifrequency Snapshot Sky Survey (MSSS) at 140 MHz. We find a scaling relation Pcav ∝ Lβ148, with a logarithmic slope of β = 0.51 ± 0.14, which is in good agreement with previous results based on data at 327 MHz. The large scatter present in this correlation confirms the conclusion reached at higher frequencies that the total radio luminosity at a single frequency is a poor predictor of the total jet power. Previous studies have shown that the magnitude of this scatter can be reduced when bolometric radio luminosity corrected for spectral aging is used. We show that including additional measurements at 148 MHz alone is insufficient to improve this correction and further reduce the scatter in the correlation. For a subset of four well-resolved sources, we examined the detected extended structures at low frequencies and compare with the morphology known from higher frequency images and Chandra X-ray maps. In the case of Perseus we discuss details in the structures of the radio mini-halo, while in the 2A 0335+096 cluster we observe new diffuse emission associated with multiple X-ray cavities and likely originating from past activity. For A2199 and MS 0735.6+7421, we confirm that the observed low-frequency radio lobes are confined to the extents known from higher frequencies. This new low-frequency analysis highlights the fact that existing cavity power to radio luminosity relations are based on a relatively narrow range of AGN outburst ages. We discuss how the correlation could be extended using low frequency data from the LOFAR Two-metre Sky Survey (LoTSS) in combination with future, complementary deeper X

  17. Grain-scale characterization of FCC/BCC correspondence relations and variant selection (United States)

    He, Youliang

    The misorientations between FCC and BCC crystals are characterized according to the common lattice correspondence relationships in terms of their parallelism conditions. Individual variants of the six models, namely the Bain, Kurdjumov-Sachs, Nishiyama-Wassermann, Pitsch, Greninger-Troiano and inverse Greninger-Troiano relations, are identified and represented in both pole figure form and in Rodrigues-Frank space with respect to various coordinate frames. In this way, the relations between the variants of these models are clarified. The orientations of the kamacite (BCC) lamellae transformed from a single prior-taenite (FCC) grain in the Gibeon meteorite were measured by analyzing the electron backscatter diffraction patterns. The local misorientations between individual FCC and BCC crystals along their common interfaces were computed and are compared with the common lattice correspondence relationships. The orientation relations between the alpha and gamma phases in the plessite regions are also characterized. The Neumann bands (mechanical twins) and their orientation variations within individual kamacite lamellae were studied and analyzed. A Nb-bearing TRIP steel was control rolled and a certain amount of austenite was retained through appropriate heat treatment. EBSD measurements were conducted on specimens deformed to various reductions and the textures (ODF's) of both the gamma and alpha phases were obtained from the measured data points. The orientations of the bainite formed within individual prior-austenite grains are compared to those expected from the common correspondence relationships and the average orientation of the prior-austenite grain. The crystallography of the bainite laths within a single packet is also characterized. The orientations of the bainite formed from individual prior-austenite grains are analyzed with respect to their parent orientations. The occurrence of variant selection at the grain scale was examined using a dislocation


    Directory of Open Access Journals (Sweden)

    Želimir Veinović


    Full Text Available Permeability tests are one of the most often performed experiments in geotechnics. Conventional methods conducted by oedometer and triaxial apparatus have many disadvantages, the most significant being the test duration. As a consequence, errors in permeability measurements could occur. On the contrary, by applying modern flow-pump method, permeability measurements can be obtained much more rapidly. Moreover, the permeability/void ratio relation can be obtained by using adequate laboratory devices. This is particularly important for soft materials, since their permeability could vary within several orders of magnitude depending on the variation of void ratio. The article presents advantages and disadvantages of the flow-pump method performed in a modified triaxial cell and hydraulic oedometer, in comparison with conventional constant head and falling head methods. The specimens were prepared from the waste stone dust, which is the product of final dimension stone processing (the paper is published in Croatian.

  19. Large-scale retrospective relative spectrophotometric self-calibration in space (United States)

    Markovič, Katarina; Percival, Will J.; Scodeggio, Marco; Ealet, Anne; Wachter, Stefanie; Garilli, Bianca; Guzzo, Luigi; Scaramella, Roberto; Maiorano, Elisabetta; Amiaux, Jérôme


    We consider the application of relative self-calibration using overlap regions to spectroscopic galaxy surveys that use slitless spectroscopy. This method is based on that developed for the Sloan Digital Sky Survey by Padmanabhan et al. in that we consider jointly fitting and marginalizing over calibrator brightness, rather than treating these as free parameters. However, we separate the calibration of the detector to detector from the full-focal-plane exposure-to-exposure calibration. To demonstrate how the calibration procedure will work, we simulate the procedure for a potential implementation of the spectroscopic component of the wide Euclid survey. We study the change of coverage and the determination of relative multiplicative errors in flux measurements for different dithering configurations. We use the new method to study the case where the flat-field across each exposure or detector is measured precisely and only exposure-to-exposure or detector-to-detector variation in the flux error remains. We consider several base dither patterns and find that they strongly influence the ability to calibrate, using this methodology. To enable self-calibration, it is important that the survey strategy connects different observations with at least a minimum amount of overlap, and we propose an 'S'-pattern for dithering that fulfils this requirement. The final survey strategy adopted by Euclid will have to optimize for a number of different science goals and requirements. The large-scale calibration of the spectroscopic galaxy survey is clearly cosmologically crucial, but is not the only one. We make our simulation code public on

  20. Structure-mechanical function relations at nano-scale in heat-affected human dental tissue. (United States)

    Sui, Tan; Sandholzer, Michael A; Le Bourhis, Eric; Baimpas, Nikolaos; Landini, Gabriel; Korsunsky, Alexander M


    The knowledge of the mechanical properties of dental materials related to their hierarchical structure is essential for understanding and predicting the effect of microstructural alterations on the performance of dental tissues in the context of forensic and archaeological investigation as well as laser irradiation treatment of caries. So far, few studies have focused on the nano-scale structure-mechanical function relations of human teeth altered by chemical or thermal treatment. The response of dental tissues to thermal treatment is thought to be strongly affected by the mineral crystallite size, their spatial arrangement and preferred orientation. In this study, synchrotron-based small and wide angle X-ray scattering (SAXS/WAXS) techniques were used to investigate the micro-structural alterations (mean crystalline thickness, crystal perfection and degree of alignment) of heat-affected dentine and enamel in human dental teeth. Additionally, nanoindentation mapping was applied to detect the spatial and temperature-dependent nano-mechanical properties variation. The SAXS/WAXS results revealed that the mean crystalline thickness distribution in dentine was more uniform compared with that in enamel. Although in general the mean crystalline thickness increased both in dentine and enamel as the temperature increased, the local structural variations gradually reduced. Meanwhile, the hardness and reduced modulus in enamel decreased as the temperature increased, while for dentine, the tendency reversed at high temperature. The analysis of the correlation between the ultrastructure and mechanical properties coupled with the effect of temperature demonstrates the effect of mean thickness and orientation on the local variation of mechanical property. This structural-mechanical property alteration is likely to be due to changes of HAp crystallites, thus dentine and enamel exhibit different responses at different temperatures. Our results enable an improved understanding of

  1. Validation of the Self-Beliefs Related to Social Anxiety Scale (United States)

    Moulds, Michelle L.; Rapee, Ronald M.


    The importance of self-beliefs in prominent models of social phobia has led to the development of measures that tap this cognitive construct. The Self-Beliefs Related to Social Anxiety (SBSA) Scale is one such measure and taps the three maladaptive belief types proposed in Clark and Wells’s model of social phobia. This study aimed to replicate and extend previous research on the psychometric properties of the SBSA. Replicating previous research, in an (undiagnosed) undergraduate sample (n = 235), the SBSA was found to have a correlated three-factor structure using confirmatory factor analyses, and the SBSA and its subscales demonstrated good internal consistency and test–retest reliability. The SBSA and its subscales also had unique relationships with social anxiety and depression, the majority of which replicated previous research. Extending previous research, the SBSA and its subscales showed good incremental validity in the undergraduate sample and good discriminative validity using the undergraduate sample and a sample of individuals with social phobia (n = 33). The SBSA’s strong theoretical basis and the findings of this study suggest that the SBSA is an ideal research and clinical tool to assess the cognitions characteristic of social phobia. PMID:23575344

  2. Multiple sclerosis lesion quantification in MR images by using vectorial scale-based relative fuzzy connectedness (United States)

    Zhuge, Ying; Udupa, Jayaram K.; Nyul, Laszlo G.


    This paper presents a methodology for segmenting PD- and T2-weighted brain magnetic resonance (MR) images of multiple sclerosis (MS) patients into white matter (WM), gray matter (GM), cerebrospinal fluid (CSF), and MS lesions. For a given vectorial image (with PD- and T2-weighted components) to be segmented, we perform first intensity inhomogeneity correction and standardization prior to segmentation. Absolute fuzzy connectedness and certain morphological operations are utilized to generate the brain intracranial mask. The optimum thresholding method is applied to the product image (the image in which voxel values represent T2 value x PD value) to automatically recognize potential MS lesion sites. Then, the recently developed technique -- vectorial scale-based relative fuzzy connectedness -- is utilized to segment all voxels within the brain intracranial mask into WM, GM, CSF, and MS lesion regions. The number of segmented lesions and the volume of each lesion are finally output as well as the volume of other tissue regions. The method has been tested on 10 clinical brain MRI data sets of MS patients. An accuracy of better than 96% has been achieved. The preliminary results indicate that its performance is better than that of the k-nearest neighbors (kNN) method.

  3. Ecotoxicity and environmental safety related to nano-scale zerovalent iron remediation applications. (United States)

    Semerád, Jaroslav; Cajthaml, Tomáš


    This mini-review summarizes the current information that has been published on the various effects of nano-scale zerovalent iron (nZVI) on microbial biota, with an emphasis on reports that highlight the positive aspects of its application or its stimulatory effects on microbiota. By nature, nZVI is a highly reactive substance; thus, the possibility of nZVI being toxic is commonly suspected. Accordingly, the cytotoxicity of nZVI and the toxicity of nZVI-related products have been detected by laboratory tests and documented in the literature. However, there are numerous other published studies on its useful nature, which are usually skipped in reviews that deal only with the phenomenon of toxicity. Therefore, the objective of this article is to review both recent publications reporting the toxic effects of nZVI on microbiota and studies documenting the positive effects of nZVI on various environmental remediation processes. Although cytotoxicity is an issue of general importance and relevance, nZVI can reduce the overall toxicity of a contaminated site, which ultimately results in the creation of better living conditions for the autochthonous microflora. Moreover, nZVI changes the properties of the site in a manner such that it can also be used as a tool in a tailor-made approach to support a specific microbial community for the decontamination of a particular polluted site.

  4. Control of the permeability of fractures in geothermal rocks (United States)

    Faoro, Igor

    This thesis comprises three journal articles that will be submitted for publication (Journal of Geophysical Research-Solid Earth). Their respective titles are: "Undrained through Drained Evolution of Permeability in Dual Permeability Media" by Igor Faoro, Derek Elsworth and Chris Marone, "Evolution of Stiffness and Permeability in Fractures Subject to Thermally-and Mechanically-Activated Dissolution" by Igor Faoro, Derek Elsworth Chris Marone; "Linking permeability and mechanical damage for basalt from Mt. Etna volcano (Italy)" by Igor Faoro, Sergio Vinciguerra, Chris Marone and Derek Elsworth. Undrained through Drained Evolution of Permeability in Dual Permeability Media: temporary permeability changes of fractured aquifers subject to earthquakes have been observed and recorded worldwide, but their comprehension still remains a complex issue. In this study we report on flow-through fracture experiments on cracked westerly cores that reproduce, at laboratory scale, those (steps like) permeability changes that have been recorded when earthquakes occur. In particular our experiments show that under specific test boundary conditions, rapid increments of pore pressure induce transient variations of flow rate of the fracture whose peak magnitudes decrease as the variations of the effective stresses increase. We identify that the observed hydraulic behavior of the fracture is due to two principal mechanisms of origin; respectively mechanical (shortening of core) and poro-elastic (radial diffusion of the pore fluid into the matrix of the sample) whose interaction cause respectively an instantaneous opening and then a progressive closure of the fracture. Evolution of Stiffness and Permeability in Fractures Subject to Thermally-and Mechanically-Activated Dissolution: we report the results of radial flow-through experiments conducted on heated samples of Westerly granite. These experiments are performed to examine the influence of thermally and mechanically activated

  5. Comparison of Mass Transfer Models for Determination of the Intestinal Permeability

    Directory of Open Access Journals (Sweden)

    P Zakeri-Milani


    Full Text Available Background and the purpose of the study: In determination of the permeability of the intestinal wall by external perfusion techniques, several models have been proposed. In the present study three models were used for experimental results that differ in their convection and diffusion assumptions. Material and Methods: Permeability coefficients for 13 compounds (metoprolol, propranolol, naproxen, ketoprofen, furosemide, hydrochlorothiazide, cimetidine, ranitidine, atenolol, piroxicam, antipyrine, ibuprofen and carbamazepine with known human intestinal permeability values were determined in anaesthetized rats by different mass transfer models and plotted versus the observed human intestinal permeabilities. Results: The calculated dimensionless wall permeability values were in the range of 0.37 - 4.85, 0.38-6.54 and 0.41-16.59 for complete radial mixing, mixing tank and laminar flow models respectively. The results indicated that all of the models work relatively well for our data despite fundamentally different assumptions. The wall permeabilities were in the order laminar flow > mixing tank > complete radial mixing. Conclusion: Although laminar flow model provides the most direct measure of the intrinsic wall permeability, it has limitations for highly permeable drugs such as ibuprofen. The normal physiological hydrodynamics is more complex and more investigation is required to find out the real hydrodynamics.

  6. Enhancing criterion-related validity through bottom-up contextualization of personality inventories: The construction of an ecological conscientiousness scale

    NARCIS (Netherlands)

    Marise Born; dr René Butter


    In this paper the concept of "ecological personality scales" is introduced. These are contextualized inventories with a high ecological validity. They are developed in a bottom-up or qualitative way and combine a relatively high trait specificity with a relatively high situational specificity. An

  7. Fast simulation of transport and adaptive permeability estimation in porous media

    Energy Technology Data Exchange (ETDEWEB)

    Berre, Inga


    -61. Amer. Math. Soc., Providence, RI, 2002. Paper B: Time-of-Flight + Fast Marching + Transport Collapse: An Alternative to Streamlines for Two-Phase Porous Media Flow with Capillary Forces? I. Berre, H. K. Dahle, K. H. Karlsen, K.-A. Lie and J. R. Natvig. In Computational Methods in Water Resources (Delft, The Netherlands, 2002), 995- 1002, Elsevier, 2002. Paper C: Fast computation of arrival times in heterogeneous media. I. Berre, K. H. Karlsen, K.-A. Lie and J. R. Natvig. Accepted for publication in Computational Geosciences. Paper D: A Level Set Corrector for an Adaptive Multiscale Permeability Prediction. I. Berre, M. Lien, T. Mannseth. Submitted to Computational Geosciences. Paper E: Combined Adaptive Multi scale and Level Set Parameter Estimation. M. Lien, I. Berre and T. Mannseth. Accepted for publication in SIAM Journal of Multiscale Modeling and Simulation. As all the papers are results of cooperation, some remarks about my contributions are necessary. In Papers A and B, methods for computing saturations based on local streamline tracing are presented. My contributions to the papers include method development and implementation for applying the transport-collapse operator in solving the saturation equation. Paper C presents an advancing front method for fast computation of time-of- flight; in addition, problems related to a previously developed marching approach [62, 61] are identified. My contributions to the paper include identification of the deficiencies of the previous marching approach in collaboration with the co-authors, development of the advancing front algorithm, and implementation of the method together with Jostein Natvig. Papers D and E present a strategy for permeability estimation based on a combination of refinement and deformation of zonation structure. My contributions to the papers include development of the approach for level-set estimation of zonation structure, and implementation of this method together with Martha Lien. All the papers were

  8. Permeability and stress-jump effects on magnetic drug targeting in a permeable microvessel using Darcy model (United States)

    Shaw, S.; Sutradhar, A.; Murthy, PVSN


    In the present paper, we investigated the influence of permeability of the carrier particle and stress jump condition on the porous spherical surface in magnetic drug targeting through a permeable microvessel. The nature of blood is defined by non-Newtonian Casson fluid in the core region of the microvessel and Newtonian fluid in the peripheral region which is located near the surface of the wall of the microvessel. The magnetic particles are considered as spherical and in nanosize, embedded in the carrier particle along with drug particles. A magnet is placed near the tumor position to generate a magnetic field. The relative motion of the carrier particle is the resultant of the fluidic force, magnetic force and Saffman drag force which are calculated for the spherical carrier particle. Trajectories of the carrier particle along the radial and axial direction are calculated. Effect of different parameters such as stress-jump constant, permeability of the carrier particle, pressure gradient, yield stress, Saffman force, volume fraction of the embedded magnetic nanoparticles, permeability of the microvessel wall, and the radius of the carrier particle on the trajectory of the carrier particle are discussed and displayed graphically.

  9. Scaling relation and regime map of explosive gas–liquid flow of binary Lennard-Jones particle system

    KAUST Repository

    Inaoka, Hajime


    We study explosive gasliquid flows caused by rapid depressurization using a molecular dynamics model of Lennard-Jones particle systems. A unique feature of our model is that it consists of two types of particles: liquid particles, which tend to form liquid droplets, and gas particles, which remain supercritical gaseous states under the depressurization realized by simulations. The system has a pipe-like structure similar to the model of a shock tube. We observed physical quantities and flow regimes in systems with various combinations of initial particle number densities and initial temperatures. It is observed that a physical quantity Q, such as pressure, at position z measured along a pipe-like system at time t follows a scaling relation Q(z,t)=Q(zt) with a scaling function Q(ζ). A similar scaling relation holds for time evolution of flow regimes in a system. These scaling relations lead to a regime map of explosive flows in parameter spaces of local physical quantities. The validity of the scaling relations of physical quantities means that physics of equilibrium systems, such as an equation of state, is applicable to explosive flows in our simulations, though the explosive flows involve highly nonequilibrium processes. In other words, if the breaking of the scaling relations is observed, it means that the explosive flows cannot be fully described by physics of equilibrium systems. We show the possibility of breaking of the scaling relations and discuss its implications in the last section. © 2011 Elsevier B.V. All rights reserved.

  10. Ammonia and urea permeability of mammalian aquaporins

    DEFF Research Database (Denmark)

    Litman, Thomas; Søgaard, Rikke; Zeuthen, Thomas


    The human aquaporins,AQP3,AQP7, AQP8,AQP9, and possibly AQP10, are permeable to ammonia, and AQP7, AQP9, and possibly AQP3, are permeable to urea. In humans, these aquaporins supplement the ammonia transport of the Rhesus (Rh) proteins and the urea transporters (UTs). The mechanism by which...... and 9 are found together with Rh proteins in cells exposed to portal blood coming from the intestine. In the kidney, AQP3 might participate in the excretion of NH(4) (+) in the collecting duct. The interplay between the ammonia-permeable aquaporins and the other types of ammonia- and urea...

  11. Scale issues in soil hydrology related to measurement and simulation: A case study in Colorado (United States)

    State variables, such as soil water content (SWC), are typically measured or inferred at very small scales while being simulated at larger scales relevant to spatial management or hillslope areas. Thus there is an implicit spatial disparity that is often ignored. Surface runoff, on the other hand, ...

  12. Fine-scale habitat characteristics related to occupancy of the Yosemite Toad, Anaxyrus canorus (United States)

    Christina T. Liang; Robert L. Grasso; Julie J. Nelson-Paul; Kim E. Vincent; Amy J. Lind


    Fine-scale habitat information can provide insight into species occupancy and persistence that is not apparent at the landscape-scale. Such information is particularly important for rare species that are experiencing population declines, such as the threatened Yosemite Toad (Anaxyrus canorus). Our study examined differences in physical...

  13. Using Relational Reasoning to Learn about Scientific Phenomena at Unfamiliar Scales (United States)

    Resnick, Ilyse; Davatzes, Alexandra; Newcombe, Nora S.; Shipley, Thomas F.


    Many scientific theories and discoveries involve reasoning about extreme scales, removed from human experience, such as time in geology and size in nanoscience. Thus, understanding scale is central to science, technology, engineering, and mathematics. Unfortunately, novices have trouble understanding and comparing sizes of unfamiliar large and…

  14. Inferring Firn Permeability from Pneumatic Testing: A Case Study on the Greenland Ice Sheet (United States)

    Sommers, Aleah N.; Rajaram, Harihar; Weber, Eliezer P.; MacFerrin, Michael J.; Colgan, William T.; Stevens, C. Max


    Across the accumulation zone of the Greenland ice sheet, summer temperatures can be sufficiently warm to cause widespread melting, as was the case in July 2012 when the entire ice sheet experienced a brief episode of enhanced surface ablation. The resulting meltwater percolates into the firn and refreezes, to create ice lenses and layers within the firn column. This is an important process to consider when estimating the surface mass balance of the ice sheet. The rate of meltwater percolation depends on the permeability of the firn, a property that is not well constrained in the presence of refrozen ice layers and lenses. We present a novel, inexpensive method for measuring in-situ firn permeability using pneumatic testing, a well-established technique used in environmental engineering and hydrology. To illustrate the capabilities of this method, we estimate both horizontal and vertical permeability from pilot tests at six sites on the Greenland ice sheet: KAN-U, DYE-2, EKT, NASA-SE, Saddle, and EastGRIP. These sites cover a range of conditions from mostly dry firn (EastGRIP), to firn with several ice layers and lenses from refrozen meltwater (Saddle, NASA-SE, EKT), to firn with extensive ice layers (DYE-2 and KAN-U). The estimated permeability in firn without refrozen ice layers at EastGRIP agrees well with the range previously reported using an air permeameter to measure permeability through firn core samples at Summit, Greenland. At sites with ice lenses or layers, we find high degrees of anisotropy, with vertical permeability much lower than horizontal permeability. Pneumatic testing is a promising and low-cost technique for measuring firn permeability, particularly as meltwater production increases in the accumulation zone and ice layers and lenses from refrozen melt layers become more prevalent. In these initial proof-of-concept tests, the estimated permeabilities represent effective permeability at the meter scale. With appropriately higher vacuum pressures

  15. Measurement of Galaxy Cluster Integrated Comptonization and Mass Scaling Relations with the South Pole Telescope

    Energy Technology Data Exchange (ETDEWEB)

    Saliwanchik, B. R.; et al.


    We describe a method for measuring the integrated Comptonization (Y (SZ)) of clusters of galaxies from measurements of the Sunyaev-Zel'dovich (SZ) effect in multiple frequency bands and use this method to characterize a sample of galaxy clusters detected in the South Pole Telescope (SPT) data. We use a Markov Chain Monte Carlo method to fit a β-model source profile and integrate Y (SZ) within an angular aperture on the sky. In simulated observations of an SPT-like survey that include cosmic microwave background anisotropy, point sources, and atmospheric and instrumental noise at typical SPT-SZ survey levels, we show that we can accurately recover β-model parameters for inputted clusters. We measure Y (SZ) for simulated semi-analytic clusters and find that Y (SZ) is most accurately determined in an angular aperture comparable to the SPT beam size. We demonstrate the utility of this method to measure Y (SZ) and to constrain mass scaling relations using X-ray mass estimates for a sample of 18 galaxy clusters from the SPT-SZ survey. Measuring Y (SZ) within a 0.'75 radius aperture, we find an intrinsic log-normal scatter of 21% ± 11% in Y (SZ) at a fixed mass. Measuring Y (SZ) within a 0.3 Mpc projected radius (equivalent to 0.'75 at the survey median redshift z = 0.6), we find a scatter of 26% ± 9%. Prior to this study, the SPT observable found to have the lowest scatter with mass was cluster detection significance. We demonstrate, from both simulations and SPT observed clusters that Y (SZ) measured within an aperture comparable to the SPT beam size is equivalent, in terms of scatter with cluster mass, to SPT cluster detection significance.

  16. SMBH Seeds: Model Discrimination with High-energy Emission Based on Scaling Relation Evolution (United States)

    Ben-Ami, Sagi; Vikhlinin, Alexey; Loeb, Abraham


    We explore the expected X-ray (0.5–2 keV) signatures from supermassive black holes (SMBHs) at high redshifts (z∼ 5{--}12) assuming various models for their seeding mechanism and evolution. Seeding models are approximated through deviations from the {M}{BH}{--}σ relation observed in the local universe, while N-body simulations of the large-scale structure are used to estimate the density of observable SMBHs. We focus on two seeding model families: (i) light seed BHs from remnants of Pop-III stars and (ii) heavy seeds from the direct collapse of gas clouds. We investigate several models for the accretion history, such as sub-Eddington accretion, slim disk models, and torque-limited growth models. We consider observations with two instruments: (i) the Chandra X-ray Observatory and (ii) the proposed Lynx. We find that all of the simulated models are in agreement with the current results from the Chandra Deep Field South, i.e., consistent with zero SMBHs in the field of view. In deep Lynx exposures, the number of observed objects is expected to become statistically significant. We demonstrate the capability to limit the phase space of plausible scenarios of the birth and evolution of SMBHs by performing deep observations at a flux limit of 1× {10}-19 {erg} {{cm}}-2 {{{s}}}-1. Finally, we show that our models are in agreement with current limits on the cosmic X-ray background (CXRB) and the expected contribution from unresolved quasars. We find that an analysis of CXRB contributions down to the Lynx confusion limit yields valuable information that can help identify the correct scenario for the birth and evolution of SMBHs.

  17. [Organizational well-being and work-related stress in health care organizations: validation of the Work-related Stress Assessment Scale]. (United States)

    Coluccia, Anna; Lorini, Francesca; Ferretti, Fabio; Pozza, Andrea; Gaetani, Marco


    The issue of the assessment of work-related stress has stimulated in recent years, the production of several theoretical paradigms and assessment tools. In this paper we present a new scale for the assessment of organizational well-being and work-related stress specific for healthcare organizations (Work-related Stress Assessment Scale - WSAS). The goal of the authors is to examine the psychometric properties of the scale, so that it can be used in the healthcare setting as a work-related stress assessment tool. The answers of 230 healthcare professionals belonging to different roles have been analyzed. The study was realized in 16 Units of the University Hospital "S. Maria alle Scotte "of Siena. The exploratory factor analysis (EFA) revealed the presence of five factors with good internal consistency and reliability, "relationship to the structure of proximity" (α = 0.93) "change" (α = 0.92), "organization of work "(α = 0.81)," relationship with the company / Governance "(α = 0.87)" working environment "(α = 0.83). The analysis of SEM (Structural Equation Models) has confirmed the goodness of the factor solution (NNFI = 0.835, CFI = 0.921, RMSEA = 0.060). The good psychometric qualities, the shortness and simplicity of the scale WSAS makes it a useful aid in the assessment of work-related stress in health care organizations.

  18. Acoustic method for permeability measurement of tissue-engineering scaffold (United States)

    Schiavi, A.; Guglielmone, C.; Pennella, F.; Morbiducci, U.


    An accurate intrinsic permeability measurement system has been designed and realized in order to quantify the inter-pore connectivity structure of tissue-engineering scaffolds by using a single (pressure) transducer. The proposed method uses a slow alternating airflow as a fluid medium and allows at the same time a simple and accurate measurement procedure. The intrinsic permeability is determined in the linear Darcy's region, and deviation from linearity due to inertial losses is also quantified. The structural parameters of a scaffold, such as effective porosity, tortuosity and effective length of cylindrical pores, are estimated using the classical Ergun's equation recently modified by Wu et al. From this relation, it is possible to achieve a well-defined range of data and associated uncertainties for characterizing the structure/architecture of tissue-engineering scaffolds. This quantitative analysis is of paramount importance in tissue engineering, where scaffold topological features are strongly related to their biological performance.

  19. Microwave absorber based on permeability-near-zero metamaterial made of Swiss roll structures (United States)

    Chen, Ke; Jia, Nan; Sima, Boyu; Zhu, Bo; Zhao, Junming; Feng, Yijun; Jiang, Tian


    In this paper, we propose a metamaterial with Swiss roll structure inclusions comprising helically wound metal/dielectric sheets to construct a slab electromagnetic (EM) wave absorber with a thickness of only 1/80 of the working wavelength. The Swiss roll structure, when analyzed under the effective medium theory, exhibits a permeability-near-zero (or mu-near-zero, MNZ) property as the real part of the permeability vanishes to zero, while the imaginary part stays relatively large at a certain frequency band. This property can be utilized to design a microwave metamaterial absorber at deep sub-wavelength thickness. The proposed absorber demonstrates near-perfect absorption at the frequency around 1.3 GHz with incidence angles up to  ±45°. A topology of orthogonal arranged Swiss roll structures are introduced to form the polarization insensitive metamaterial absorber. Prototypes have been fabricated and measured either in a TEM cell or in a microwave anechoic chamber to validate the absorption performance as well as the design principle. The proposed design could be easily scaled to work at other frequencies as a MNZ metamaterial or ultrathin EM absorber.

  20. Dispersion and dissolution of a buoyancy driven gas plume in a layered permeable rock (United States)

    Woods, Andrew W.; Norris, Simon


    Using a series of simplified models, we explore the controls on the migration, dispersion and eventual dissolution of a plume of hydrogen gas which may, in principle, rise under buoyancy through a layered permeable rock if released from a Geological Disposal Facility (GDF). We show that the presence of low permeability shale barriers causes the gas to spread laterally as it rises. Averaging over the length scale of the barriers, we use expressions for the Darcy velocity of the gas to describe the dispersion of a tracer and illustrate the effect with a new experiment using a baffled Hele-Shaw cell. While the plume is flowing, a large volume of gas may build up beneath the barriers. If the gas flux subsequently wanes, much of the gas will drain upward through the formation and spread on the upper impermeable boundary of the formation. However, a significant capillary-trapped wake of gas may develop beneath each barrier. Owing to the low solubility of hydrogen in water and assuming relatively slow groundwater flow rates, this trapped hydrogen may require a period of tens to hundreds of thousands of years to dissolve and form a cloud of hydrogen rich water. Although simplified, these models provide a framework to assess the possible travel times and pathways of such a gas plume.

  1. Importance of proper scaling of aerobic power when relating to cardiometabolic risk factors in children

    DEFF Research Database (Denmark)

    McMurray, Robert; Hosick ‎, Peter; Bugge, Anna


    BACKGROUND: The relationship between cardiometabolic risk factors (CMRF) and aerobic power (VO(2max)) scaled as mL O(2) per kilogram body mass is controversial because mass includes both fat and fat-free mass, and fat mass is independently associated with the CMRF. AIM: To examine common units used....... VO(2max) was estimated in mL/min from cycle ergometry and scaled to body mass (kg), fat free mass (kg(FFM)), body surface area (m(2)), height (cm) and allometric (mL/kg(0.67)/min). RESULTS: Unadjusted correlations between CMRF and many of the scaled VO(2max) units were significant (p

  2. Adaptation of a pattern-scaling approach for assessment of local (village/valley) scale water resources and related vulnerabilities in the Upper Indus Basin (United States)

    Forsythe, Nathan; Kilsby, Chris G.; Fowler, Hayley J.; Archer, David R.


    sites for medium-scale infrastructure projects. These catchments are placed in their context within the hydrological regime classification using the spatial data and (remote sensing) observations as well as river gauging measurements. The study assesses the degree of similarity with the larger basins of the same hydrological regime. This assessment focuses on the measured response to observed climate variable anomalies. The smallest scale considered is comprised of a number of case studies at the ungauged village/valley scale. These examples are based on the delineation of areas to which specific communities (villages) have customary (riparian) water rights. These examples were suggested by non-governmental organisations working on grassroots economic development initiatives and small-scale infrastructure projects in the region. The direct observations available for these subcatchments are limited to spatial data (elevation, snow parameters). The challenge at this level is to accurately extrapolate areal values (precipitation, temperature, runoff) from point observations at the basin scale. The study assesses both the degree of similarity in the distribution of spatial parameters to the larger gauged basins and the interannual variability (spatial heterogeneity) of remotely-sensed snow cover and snow-water-equivalent at this subcatchment scale. Based upon the characterisation of spatial and interannual variability at these three spatial scales, the challenges facing local water resource managers and infrastructure operators are enumerated. Local vulnerabilities include, but are not limited to, varying thresholds in irrigation water requirements based on crop-type, minimum base flows for micro-hydropower generation during winter (high load) months and relatively small but growing demand for domestic water usage. In conclusion the study posits potential strategies for managing interannual variability and potential emerging trends. Suggested strategies are guided by the

  3. Relating rheology to geometry in large-scale natural shear zones (United States)

    Platt, John


    The geometry and width of the ductile roots of plate boundary scale faults are very poorly understood. Some field and geophysical data suggests widths of tens of km in the lower crust, possibly more in the upper mantle. Other observations suggest they are much narrower. Dip slip shear zones may flatten out and merge into zones of subhorizontal lower crustal or asthenospheric flow. The width of a ductile shear zone is simply related to relative velocity and strain rate. Strain rate is related to stress through the constitutive relationship. Can we constrain the stress, and do we understand the rheology of materials in ductile shear zones? A lot depends on how shear zones are initiated. If they are localized by pre-existing structures, width and/or rheology may be inherited, and we have too many variables. If shear zones are localized primarily by shear heating, initial shear stress has to be very high (> 1 GPa) to overcome conductive heat loss, and very large feedbacks (both positive and negative) make the system highly unstable. Microstructural weakening requires a minimum level of stress to cause deformation and damage in surrounding rock, thereby buffering the stress. Microstructural weakening leads to grain-size sensitive creep, for which we have constitutive laws, but these are complicated by phase mixing in polyphase materials, by viscous anisotropy, by hydration, and by changes in mineral assemblage. Here are some questions that need to be addressed. (1) If grain-size reduction by dynamic recrystallization results in a switch to grain-size sensitive creep (GSSC) in a stress-buffered shear zone, does dynamic recrystallization stop? Does grain growth set in? If grain-size is still controlled by dislocation processes, then the effective stress exponent for GSSC is 4-5, even though the dominant mechanism may be diffusion and/or grain-boundary sliding (GBS). (2) Is phase mixing in ultramylonites primarily a result of GBS + neighbour switching, creep cavitation and

  4. Different Methods of Predicting Permeability in Shale

    DEFF Research Database (Denmark)

    Mbia, Ernest Ncha; Fabricius, Ida Lykke; Krogsbøll, Anette

    Permeability is often very difficult to measure or predict in shale lithology. In this work we are determining shale permeability from consolidation tests data using Wissa et al., (1971) approach and comparing the results with predicted permeability from Kozeny’s model. Core and cuttings materials...... in shale useful in assessing their integrity for CO2 storage, gas shale exploitation and other engineering applications....... were obtained from Fjerritslev shale Formation in Juassic interval of Stenlille and Vedsted on-shore wells of Danish basin. The calculated permeability from specific surface and porosity vary from 0.09 to 48.53 μD while that calculated from consolidation tests data vary from 1000 μD at a low vertical...

  5. Permeability Tests on Silkeborg Sand No. 0000

    DEFF Research Database (Denmark)

    Lund, Willy; Jakobsen, Kim Parsberg

    The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends on the charact......The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends...... on the characteristics of the soil matrix, the permeability is determined for different void ratios. All tests are performed on reconstituted specimens of Silkeborg Sand No. 0000. The permeability is determined by use of a falling head apparatus. The apparatus, test procedures and the analysis method are described...

  6. Permeability Tests on Eastern Scheldt Sand

    DEFF Research Database (Denmark)

    Jakobsen, Kim Parsberg

    The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends on the charact......The flow through porous media plays an important role in various engineering disciplines, as for example in ground water hydrology and soil mechanics. In the present study the permeability is determined for a fine, saturated sand. As the flow through a porous media strongly depends...... on the characteristics of the soil matrix, the permeability is determined for different void ratios. All tests are performed on reconstituted specimens of Eastern Scheldt Sand. The permeability is determined by use of a falling head apparatus. Finally the test results are briefly summarised and a relationship between...

  7. Biopartitioning micellar chromatography to predict skin permeability. (United States)

    Martínez-Pla, J J; Martín-Biosca, Y; Sagrado, S; Villanueva-Camañas, R M; Medina-Hernández, M J


    Dermal absorption of chemicals is an area of increasing interest to the pharmaceutical and cosmetic industries, as well as in dermal exposure and risk assessment processes. In this paper the capability of biopartitioning micellar chromatography (BMC) as an in vitro technique to describe compound percutaneous absorption is evaluated. A multivariate study (principal component analysis, partial least squares) is performed in order to evaluate the importance of some physicochemical variables on the skin permeability constant values. From these results, a quantitative retention-activity relationship model for predicting the skin permeability constants that uses the BMC retention data and melting point as descriptor variables was obtained from a heterogeneous set of 43 compounds. The main advantage of the proposed methodology is that it allows the obtention of permeability constants of ionic compound and it can be very useful to predict the effect of pH of vehicle on the skin permeability of xenobiotics. Copyright 2003 John Wiley & Sons, Ltd.

  8. Oil permeability variations on lagoon sand beaches in the Patos-Guaíba system in Rio Grande do Sul, Brazil. (United States)

    Oliveira, Elaine Baroni; Nicolodi, João Luiz


    Permeability is the ability of a sediment deposit to allow fluids to pass through it. It depends on the local types of sediments. When the fluid is oil, high permeability implies greater interaction with the site and more extensive damage, which makes recovery most difficult. Knowledge of permeability oscillations is necessary to understand oil behavior and improve cleanup techniques. The goal is to determine oil permeability variations on lagoon sand beaches. Oil permeability tests were performed at the beach face, using a Modified Phillip Dunne Permeameter and parameters were sampled. Permeability of lagoon beaches is driven by grain diameter and roundness, soil compaction, and depth of the water table. Factors that enhance permeability include: sand sorting, vertical distribution of sediments and gravel percentage. High permeability on lagoon beaches is related to polymodal distribution, to the sediment package, and to the system's low mobility. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Validating survey measurement scales for AIDS-related knowledge and stigma among construction workers in South Africa. (United States)

    Bowen, Paul; Govender, Rajen; Edwards, Peter


    Construction workers in South Africa are regarded as a high-risk group in the context of HIV/AIDS. HIV testing is pivotal to controlling HIV transmission and providing palliative care and AIDS-related knowledge and stigma are key issues in addressing the likelihood of testing behaviour. In exploring these issues, various studies have employed an 11-item AIDS-related knowledge scale (Kalichman and Simbayi, AIDS Care 16:572-580, 2004) and a 9-item stigma scale (Kalichman et al., AIDS Behav 9:135-143, 2005), but little evidence exists confirming the psychometric properties of these scales. Using survey data from 512 construction workers in the Western Cape, South Africa, this research examines the validity and reliability of the two scales through exploratory and confirmatory factor analysis and internal consistency tests. From confirmatory factor analysis, a revised 10-item knowledge scale was developed (χ2 /df ratio = 1.675, CFI = 0.982, RMSEA = 0.038, and Hoelter (95 %) = 393). A revised 8-item stigma scale was also developed (χ2 /df ratio = 1.929, CFI = 0.974, RMSEA = 0.045, and Hoelter (95 %) = 380). Both revised scales demonstrated good model fit and all factor loadings were significant (p Limitations of the original survey from which the data was obtained include the failure to properly account for respondent selection of language for completion of the survey, use of ethnicity as a proxy for identifying the native language of participants, the limited geographical area from which the survey data was collected, and the limitations associated with the convenience sample. A limitation of the validation study was the lack of available data for a more robust examination of reliability beyond internal consistency, such as test-retest reliability. The revised knowledge and stigma scales offered here hold considerable promise as measures of AIDS-related knowledge and stigma among South African construction workers.

  10. Pneumatic fracturing of low permeability media

    Energy Technology Data Exchange (ETDEWEB)

    Schuring, J.R. [New Jersey Institute of Technology, Newark, NJ (United States)


    Pneumatic fracturing of soils to enhance the removal and treatment of dense nonaqueous phase liquids is described. The process involves gas injection at a pressure exceeding the natural stresses and at a flow rate exceeding the permeability of the formation. The paper outlines geologic considerations, advantages and disadvantages, general technology considerations, low permeability media considerations, commercial availability, efficiency, and costs. Five case histories of remediation using pneumatic fracturing are briefly summarized. 11 refs., 2 figs., 1 tab.

  11. Surface sedimentation at permeable pavement systems

    DEFF Research Database (Denmark)

    Støvring, Jan; Dam, Torben; Jensen, Marina Bergen


    Newly installed permeable pavement (PP) systems provide high surface infiltration capacity, but the accumulation of sediments causes a decrease in capacity over time, eventually leading to surface clogging. With the aim of investigating local sedimentation processes and the importance of restorat......Newly installed permeable pavement (PP) systems provide high surface infiltration capacity, but the accumulation of sediments causes a decrease in capacity over time, eventually leading to surface clogging. With the aim of investigating local sedimentation processes and the importance...

  12. Permeability and stress-jump effects on magnetic drug targeting in a permeable microvessel using Darcy model

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, S., E-mail: [Department of Mathematics and Statistical Sciences, Botswana International University of Science and Technology, Private Bag 16, Palapye (Botswana); Sutradhar, A.; Murthy, PVSN [Department of Mathematics, Indian Institute of Technology Kharagpur, Kharagpur 721302, West Bengal (India)


    In the present paper, we investigated the influence of permeability of the carrier particle and stress jump condition on the porous spherical surface in magnetic drug targeting through a permeable microvessel. The nature of blood is defined by non-Newtonian Casson fluid in the core region of the microvessel and Newtonian fluid in the peripheral region which is located near the surface of the wall of the microvessel. The magnetic particles are considered as spherical and in nanosize, embedded in the carrier particle along with drug particles. A magnet is placed near the tumor position to generate a magnetic field. The relative motion of the carrier particle is the resultant of the fluidic force, magnetic force and Saffman drag force which are calculated for the spherical carrier particle. Trajectories of the carrier particle along the radial and axial direction are calculated. Effect of different parameters such as stress-jump constant, permeability of the carrier particle, pressure gradient, yield stress, Saffman force, volume fraction of the embedded magnetic nanoparticles, permeability of the microvessel wall, and the radius of the carrier particle on the trajectory of the carrier particle are discussed and displayed graphically. - Highlights: • In the present manuscript, we considered the porous carrier particle which provide a larger surface area contact with the fluid than the solid spherical carrier particle. It shows that the porous carrier particle are captured easily than the solid carrier particle. • Introduce Suffman force on the carrier particle which commences an additional resistance which acts opposite to the surface wall and helps the particles to go away from the tumor position. • Considered stress jump condition at the surface of the porous carrier particle which enhanced the tendency of the carrier particle to be capture near the tumor. • Used Darcy model to define the permeability of the wall of the microvessel.

  13. Understanding Emerging Impacts and Requirements Related to Utility-Scale Solar Development

    Energy Technology Data Exchange (ETDEWEB)

    Hartmann, Heidi M. [Argonne National Lab. (ANL), Argonne, IL (United States); Grippo, Mark A. [Argonne National Lab. (ANL), Argonne, IL (United States); Heath, Garvin A. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Macknick, Jordan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Smith, Karen P. [Argonne National Lab. (ANL), Argonne, IL (United States); Sullivan, Robert G. [Argonne National Lab. (ANL), Argonne, IL (United States); Walston, Leroy J. [Argonne National Lab. (ANL), Argonne, IL (United States); Wescott, Konstance L. [Argonne National Lab. (ANL), Argonne, IL (United States)


    Utility-scale solar energy plays an important role in the nation’s strategy to address climate change threats through increased deployment of renewable energy technologies, and both the federal government and individual states have established specific goals for increased solar energy development. In order to achieve these goals, much attention is paid to making utility-scale solar energy cost-competitive with other conventional energy sources, while concurrently conducting solar development in an environmentally sound manner.

  14. Manufacturing and design of the offshore structure Froude scale model related to basin restrictions (United States)

    Scurtu, I. C.


    Manufacturing steps for a modern three - column semi-submersible structure are delivered using CFD/CAE software and actual Froude scaled model testing. The three- column offshore is part of the Wind Float Project already realized as prototype for wind energy extraction in water depths more than 40 meters, and the actual model will not consider the wind turbine. The model will have heave plates for a smaller heave motion in order to compare it with the case without heave plates. The heave plates will be part of the Froude scale model.. Using a smaller model will determine a smaller heave motion and this will affect predictions of the vertical movement of the three- column offshore structure in real sea. The Froude criterion is used for the time, speed and acceleration scale. The scale model is manufactured from steel and fiberglass and all parts are subjected to software analysis in order to get the smallest stress in connections inside the model. The model mass was restricted by scale dimensions and also the vertical position of centre gravity will be considered during the manufacturing and design process of the Froude scale offshore structure. All conditions must converge in model manufacturing and design in order to get the best results to compare with real sea states and heave motion data.

  15. Origin of Permeability and Structure of Flows in Fractured Media (United States)

    De Dreuzy, J.; Darcel, C.; Davy, P.; Erhel, J.; Le Goc, R.; Maillot, J.; Meheust, Y.; Pichot, G.; Poirriez, B.


    After more than three decades of research, flows in fractured media have been shown to result from multi-scale geological structures. Flows result non-exclusively from the damage zone of the large faults, from the percolation within denser networks of smaller fractures, from the aperture heterogeneity within the fracture planes and from some remaining permeability within the matrix. While the effect of each of these causes has been studied independently, global assessments of the main determinisms is still needed. We propose a general approach to determine the geological structures responsible for flows, their permeability and their organization based on field data and numerical modeling [de Dreuzy et al., 2012b]. Multi-scale synthetic networks are reconstructed from field data and simplified mechanical modeling [Davy et al., 2010]. High-performance numerical methods are developed to comply with the specificities of the geometry and physical properties of the fractured media [Pichot et al., 2010; Pichot et al., 2012]. And, based on a large Monte-Carlo sampling, we determine the key determinisms of fractured permeability and flows (Figure). We illustrate our approach on the respective influence of fracture apertures and fracture correlation patterns at large scale. We show the potential role of fracture intersections, so far overlooked between the fracture and the network scales. We also demonstrate how fracture correlations reduce the bulk fracture permeability. Using this analysis, we highlight the need for more specific in-situ characterization of fracture flow structures. Fracture modeling and characterization are necessary to meet the new requirements of a growing number of applications where fractures appear both as potential advantages to enhance permeability and drawbacks for safety, e.g. in energy storage, stimulated geothermal energy and non-conventional gas productions. References Davy, P., et al. (2010), A likely universal model of fracture scaling and

  16. Intestinal permeability in patients with atopic eczema. (United States)

    Bjarnason, I; Goolamali, S K; Levi, A J; Peters, T J


    Intestinal permeability was investigated in adult patients with atopic eczema by in vivo and in vitro techniques. Patients with symptoms of 'immediate' food allergy were specifically excluded. A 51Cr-labelled ethylenediaminetetraacetate absorption test was carried out in eighteen patients. Their mean (+/- s.d.) 24-hour urine excretion following oral administration of the test substance (2.1 +/- 0.9%) did not differ significantly from that of thirty-four normal controls (1.9 +/- 0.5%). Small bowel permeability was estimated directly in jejunal mucosal samples in ten patients with three permeability probes of differing molecular weight. Mucosal permeability did not differ significantly from that of fifteen control patients for any of the test substances. Two patients had abnormal results by both tests and in one this was due to coeliac disease. These results suggest that altered intestinal permeability is not important in the pathogenesis of eczema. Patients demonstrating increased intestinal permeability should undergo jejunal biopsy to exclude significant small bowel disease.

  17. Charge Inversion in semi-permeable membranes (United States)

    Das, Siddhartha; Sinha, Shayandev; Jing, Haoyuan

    Role of semi-permeable membranes like lipid bilayer is ubiquitous in a myriad of physiological and pathological phenomena. Typically, lipid membranes are impermeable to ions and solutes; however, protein channels embedded in the membrane allow the passage of selective, small ions across the membrane enabling the membrane to adopt a semi-permeable nature. This semi-permeability, in turn, leads to electrostatic potential jump across the membrane, leading to effects such as regulation of intracellular calcium, extracellular-vesicle-membrane interactions, etc. In this study, we theoretically demonstrate that this semi-permeable nature may trigger the most remarkable charge inversion (CI) phenomenon in the cytosol-side of the negatively-charged lipid bilayer membrane that are selectively permeable to only positive ions of a given salt. This CI is manifested as the changing of the sign of the electrostatic potential from negative to positive from the membrane-cytosol interface to deep within the cytosol. We study the impact of the parameters such as the concentration of this salt with selectively permeable ions as well as the concentration of an external salt in the development of this CI phenomenon. We anticipate such CI will profoundly influence the interaction of membrane and intra-cellular moieties (e.g., exosome or multi-cellular vesicles) having implications for a host of biophysical processes.

  18. The Cognitive Abilities Scale--Second Edition Preschool Form: Studies of Concurrent Criterion-Related, Construct, and Predictive Criterion-Related Validity (United States)

    Swanson, Jennifer R.; Bradley-Johnson, Sharon; Johnson, C. Merle; O'Dell, Anna Rubenaker


    Three studies examine the validity of the Preschool Form of the Cognitive Abilities Scale--Second Edition (CAS-2). Significant high concurrent criterion-related validity correlations, corrected for restricted range, are found between the CAS-2 and the Detroit Test of Learning Ability--Primary: Third Edition for 26 three-year-olds (r[subscript c] =…

  19. Frictional stability-permeability relationships for fractures in shales: Friction-Permeability Relationships

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Yi [Department of Energy and Mineral Engineering, EMS Energy Institute, and G3 Center, Pennsylvania State University, University Park Pennsylvania USA; Elsworth, Derek [Department of Energy and Mineral Engineering, EMS Energy Institute, and G3 Center, Pennsylvania State University, University Park Pennsylvania USA; Department of Geosciences, EMS Energy Institute, and G3 Center, Pennsylvania State University, University Park Pennsylvania USA; Wang, Chaoyi [Department of Energy and Mineral Engineering, EMS Energy Institute, and G3 Center, Pennsylvania State University, University Park Pennsylvania USA; Ishibashi, Takuya [Department of Energy and Mineral Engineering, EMS Energy Institute, and G3 Center, Pennsylvania State University, University Park Pennsylvania USA; Fukushima Renewable Energy Institute, National Institute of Advanced Industrial Science and Technology, Koriyama Japan; Fitts, Jeffrey P. [Department of Civil and Environmental Engineering, Princeton University, Princeton New Jersey USA


    There is wide concern that fluid injection in the subsurface, such as for the stimulation of shale reservoirs or for geological CO2 sequestration (GCS), has the potential to induce seismicity that may change reservoir permeability due to fault slip. However, the impact of induced seismicity on fracture permeability evolution remains unclear due to the spectrum of modes of fault reactivation (e.g., stable versus unstable). As seismicity is controlled by the frictional response of fractures, we explore friction-stability-permeability relationships through the concurrent measurement of frictional and hydraulic properties of artificial fractures in Green River shale (GRS) and Opalinus shale (OPS). We observe that carbonate-rich GRS shows higher frictional strength but weak neutral frictional stability. The GRS fracture permeability declines during shearing while an increased sliding velocity reduces the rate of permeability decline. By comparison, the phyllosilicate-rich OPS has lower friction and strong stability while the fracture permeability is reduced due to the swelling behavior that dominates over the shearing induced permeability reduction. Hence, we conclude that the friction-stability-permeability relationship of a fracture is largely controlled by mineral composition and that shale mineral compositions with strong frictional stability may be particularly subject to permanent permeability reduction during fluid infiltration.

  20. Comparative field permeability measurement of permeable pavements using ASTM C1701 and NCAT permeameter methods. (United States)

    Li, Hui; Kayhanian, Masoud; Harvey, John T


    Fully permeable pavement is gradually gaining support as an alternative best management practice (BMP) for stormwater runoff management. As the use of these pavements increases, a definitive test method is needed to measure hydraulic performance and to evaluate clogging, both for performance studies and for assessment of permeability for construction quality assurance and maintenance needs assessment. Two of the most commonly used permeability measurement tests for porous asphalt and pervious concrete are the National Center for Asphalt Technology (NCAT) permeameter and ASTM C1701, respectively. This study was undertaken to compare measured values for both methods in the field on a variety of permeable pavements used in current practice. The field measurements were performed using six experimental section designs with different permeable pavement surface types including pervious concrete, porous asphalt and permeable interlocking concrete pavers. Multiple measurements were performed at five locations on each pavement test section. The results showed that: (i) silicone gel is a superior sealing material to prevent water leakage compared with conventional plumbing putty; (ii) both methods (NCAT and ASTM) can effectively be used to measure the permeability of all pavement types and the surface material type will not impact the measurement precision; (iii) the permeability values measured with the ASTM method were 50-90% (75% on average) lower than those measured with the NCAT method; (iv) the larger permeameter cylinder diameter used in the ASTM method improved the reliability and reduced the variability of the measured permeability. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. CO2-induced dissolution of low permeability carbonates. Part I: Characterization and experiments (United States)

    Smith, Megan M.; Sholokhova, Yelena; Hao, Yue; Carroll, Susan A.


    in later-time solution pH levels at the core outlet. Given the impact of heterogeneity within low permeability cores, effort should be taken to incorporate smaller-scale heterogeneity into predictive models and such an averaging approach (utilizing the data and observations discussed here) is the topic of our companion manuscript (see Hao et al., 2013). Solution chemistry results indicated that steady-state carbonate mass transfer conditions were attained in the Marly dolostone experiments and during the earlier (pre-pressure breakthrough) portions of the Vuggy limestone experiments. Steady-state calcium and magnesium concentrations coincided with outlet solutions that were calculated to be at or very near to equilibrium with respect to both calcite and dolomite, relative to available thermodynamic data and considering experimental data scatter. Carbonate mass transfer data were evaluated against a variety of proposed carbonate dissolution mechanisms, including both pH- and pCO2-dependent expressions as well as a simplified pH-independent formulation. Based on this analysis, the calcite reaction rate coefficient was estimated to be ∼17 times faster than that for dolomite dissolution under our experimental conditions. This ratio is consistent with the use of rate equations that depend on carbonate mineral saturation without specifying additional dependence on solution pH or CO2 levels, and may be a result of the narrow experimental pH range. In addition, solution chemistry data were combined with time-dependent pressure data to constrain the exponent in a power-law expression describing the relationship between evolving porosity and permeability within the Vuggy limestones. This relationship as well as proposed carbonate kinetic expressions are further evaluated in our companion paper (see Hao et al., 2013).

  2. Measuring the relative resilience of subarctic lakes to global change: redundancies of functions within and across temporal scales (United States)

    Angeler, David G.; Allen, Craig R.; Johnson, Richard K.


    . The relative ‘intactness’ of these scales that are unaffected by global change and the persistence of functions at those scales may safeguard the whole system from the potential loss of functions at the scale at which global change impacts can be substantial. Thus, an understanding of scale-specific processes provides managers with a realistic assessment of vulnerabilities and the relative resilience of ecosystems to environmental change. Explicit consideration of ‘intact’ and ‘affected’ scales in analyses of global change impacts provides opportunities to tailor more specific management plans.

  3. Measurement of the magnetic permeability of amorphous magnetic microwires by using their antenna resonance (United States)

    Lopez-Dominguez, V.; Garcia, M. A.; Marin, P.; Hernando, A.


    We present here a new free space method to measure the magnetic permeability of a single amorphous magnetic microwire (AMM) at microwave frequencies. The technique consists in inducing a high frequency electric current along the AMM axis by illumination with an electromagnetic wave at antenna resonance conditions. Fitting the induced electric current to the Hallen-Pocklington equation allows computing the relative magnetic permeability of the microwire as a function of the wave frequency. The method results particularly useful for the study of the giant magnetoimpedance effect of AMM by measuring the magnetic permeability upon the application of DC magnetic fields.

  4. Hyper-scaling relations in the conformal window from dynamic AdS/QCD (United States)

    Evans, Nick; Scott, Marc


    Dynamic AdS/QCD is a holographic model of strongly coupled gauge theories with the dynamics included through the running anomalous dimension of the quark bilinear, γ. We apply it to describe the physics of massive quarks in the conformal window of SU(Nc) gauge theories with Nf fundamental flavors, assuming the perturbative two-loop running for γ. We show that to find regular, holographic renormalization group flows in the infrared, the decoupling of the quark flavors at the scale of the mass is important, and enact it through suitable boundary conditions when the flavors become on shell. We can then compute the quark condensate and the mesonic spectrum (Mρ,Mπ,Mσ) and decay constants. We compute their scaling dependence on the quark mass for a number of examples. The model matches perturbative expectations for large quark mass and naïve dimensional analysis (including the anomalous dimensions) for small quark mass. The model allows study of the intermediate regime where there is an additional scale from the running of the coupling, and we present results for the deviation of scalings from assuming only the single scale of the mass.

  5. Ca2+-permeable AMPA receptors in homeostatic synaptic plasticity

    Directory of Open Access Journals (Sweden)

    Hey-Kyoung eLee


    Full Text Available Neurons possess diverse mechanisms of homeostatic adaptation to overall changes in neural and synaptic activity, which are critical for proper brain functions. Homeostatic regulation of excitatory synapses has been studied in the context of synaptic scaling, which allows neurons to adjust their excitatory synaptic gain to maintain their activity within a dynamic range. Recent evidence suggests that one of the main mechanisms underlying synaptic scaling is by altering the function of postsynaptic AMPA receptors (AMPARs, including synaptic expression of Ca2+-permeable (CP- AMPARs. CP-AMPARs endow synapses with unique properties, which may benefit adaptation of neurons to periods of inactivity as would occur when a major input is lost. This review will summarize how synaptic expression of CP-AMPARs is regulated during homeostatic synaptic plasticity in the context of synaptic scaling, and will address the potential functional consequences of altering synaptic CP-AMPAR content.

  6. Relative Seismic Source Scaling of North Korean Nuclear Explosions Utilizing Regional Data (United States)

    Park, J.; Che, I.; Hayward, C.; Stump, B. W.


    The relative source scaling of the 2006, 2009, and 2013 North Korean nuclear explosions is assessed using a Mueller and Murphy (1971) source model based interpretation of regional seismic station spectral ratios. Analyzing the regional phases, Pn, Pg, Sn, and Lg, separately provides source model estimates. Data from the KSRS seismic array in South Korea, MDJ seismic station in China, and the seismo-acoustic arrays: BRDAR, CHNAR, and KSGAR, cooperatively operated by KIGAM and SMU were used. Spectral levels of the second test are 3-4 times more energetic than the first test at low frequencies and become more equal in the 6-9 Hz frequency band as a result of source corner frequency effects. The third explosion is approximately 3 times more energetic than the second test at long periods, and 7-10 times more energetic than the first. A grid search method is used to explore the range of acceptable source models for each explosion resulting in estimates of yield and depth. Explosions that occurred in 2009 and 2013 are analyzed first because they are near one another (~450 m). The search space spanned from 10 to 1010 m at 50 m intervals and from 1.0 to 15.0 kt at 0.5 kt intervals. Summary results from the range of acceptable models are presented in terms of depth and yield ratios for the third to second test. The range of acceptable depth ratios for a goodness-of-fit (GOF) value of less than 10 was from 0.6-2.0 for Pn, 0.6-1.5 for Pg and 0.5-1.3 for both Sn and Lg. The best value (BV), with the smallest GOF, for depth ratios were approximately 1.0 for Pn, 0.9 for Pg, and 0.8 for Sn and Lg. The range estimates for the yield ratios were 2.2-4.0 (BV of 2.7) for Pn, 2.0-3.8 (BV of 2.3) for Pg, and 2.0-3.8 (BV of 2.6) for Sn and Lg. In the case of 2009/2006 explosions, the depth ratios are 0.5-2.8 (BV of 1.2) for Pn and 0.8 - 1.8 (BV of 1.1) for Pg, and the yield ratios are 3.0-6.0 (BV of 4.2) for Pn and 3.3-5.0 (BV of 4.0) for Pg, consistent with result by Kim et al. (2009

  7. Transport coefficients and validity of the Stokes-Einstein relation in metallic melts: From excess entropy scaling laws (United States)

    Shrivastava, Ruchi; Mishra, Raj Kumar


    Using the pair correlation function obtained via square well (SW) model [Mishra et al., 2015 Chem. Phys. 457 13], we calculate the pair excess entropy of liquid metals and determined the diffusion coefficients via Dzugutov's excess entropy-diffusivity scaling relation. Further, the applicability of the Stokes-Einstein relation for SW potential is validated by comparing the computed shear viscosity coefficients (ηV) of liquid metals with the available experimental data. Reduced ηV of considered systems has been derived and scaled with the excess entropy. We compute isothermal compressibility, surface tension and surface entropy of the investigated liquids by using diffusion coefficient data obtained from excess entropy scaling law. It is found that the computed values are in good agreement with the corresponding experimental data. Thus, we demonstrate that the Dzugutov scheme can be applied successfully to SW liquid metals to correlate their microscopic structural functions with their surface and thermodynamic properties.

  8. Test-retest reliability of Antonovsky's 13-item sense of coherence scale in patients with hand-related disorders

    DEFF Research Database (Denmark)

    Hansen, Alice Ørts; Kristensen, Hanne Kaae; Cederlund, Ragnhild


    PURPOSE: To report on the distribution and test-retest reliability of Antonovsky's 13-item Sense of Coherence (SOC-13) Scale in patients with hand-related disorders (HRD). Links between the SOC-13 score and factors such as age, number of days between date of injury and start of rehabilitation......, gender and educational level were explored. METHOD: Survey with test-retest, using self-administered questionnaire. SOC-13 was completed before starting rehabilitation at an outpatient clinic after 14 days and three months. Adult patients with HRD were included. RESULTS: A total of 170 participants...... to be a powerful tool to measure the ICF component personal factors, which could have an impact on patients' rehabilitation outcomes. Implications for rehabilitation Antonovsky's SOC-13 scale showed test-retest reliability for patients with hand-related disorders. The SOC-13 scale could be a suitable tool to help...

  9. Theoretical Re-evaluations of Scaling Relations between SMBHs and Their Host Galaxies—1. Effect of Seed BH Mass

    Directory of Open Access Journals (Sweden)

    Hikari Shirakata


    Full Text Available We use a semi-analytic model of galaxy formation and investigate how the mass of a seed black hole affect the scaling relation between black hole mass and bulge mass at z ~ 0. When the mass of the seed is set at 105M⊙, we find that the model results become inconsistent with recent observational results of the scaling relation for dwarf galaxies. On the other hand, when we set seed black hole mass as 103M⊙ or as randomly chosen value within a 103-5M⊙ range, we find the results are consistent with observational results including the dispersion. We also find that black hole mass—bulge mass relations for less massive bulges at z ~ 0 put stronger constraints on the seed BH mass than the relations at higher redshifts.

  10. Attitude toward euthanasia scale: psychometric properties and relations with religious orientation, personality, and life satisfaction. (United States)

    Aghababaei, Naser; Wasserman, Jason Adam


    End-of-life decisions (ELDs) represent a controversial subject, with ethical dilemmas and empirical ambiguities that stand at the intersection of ethics and medicine. In a non-Western population, we examined individual differences in perceiving ELDs that end the life of a patient as acceptable and found that an attitude toward euthanasia (ATE) scale consists of 2 factors representing voluntary and nonvoluntary euthanasia. Also, acceptance of ELDs that end the life of a patient negatively correlated with life satisfaction, honesty-humility, conscientiousness, and intrinsic and extrinsic personal motivation toward religion. These findings provided additional construct validity of the ATE scale.

  11. Nano-scale structure in membranes in relation to enzyme action - computer simulation vs. experiment

    DEFF Research Database (Denmark)

    Høyrup, P.; Jørgensen, Kent; Mouritsen, O.G.


    There is increasing theoretical and experimental evidence indicating that small-scale domain structure and dynamical heterogeneity develop in lipid membranes as a consequence of the the underlying phase transitions and the associated density and composition fluctuations. The relevant coherence le...... mixtures show that the enzyme activity is modulated by nano-scale lipid-domain formation in the lipid bilayer and lead to a characteristic lag-burst behavior. The simulations are found to be in semi-quantitative agreement with experimental data....

  12. L-Band SAR Backscatter Related to Forest Cover, Height and Aboveground Biomass at Multiple Spatial Scales across Denmark

    Directory of Open Access Journals (Sweden)

    Neha P. Joshi


    Full Text Available Mapping forest aboveground biomass (AGB using satellite data is an important task, particularly for reporting of carbon stocks and changes under climate change legislation. It is known that AGB can be mapped using synthetic aperture radar (SAR, but relationships between AGB and radar backscatter may be confounded by variations in biophysical forest structure (density, height or cover fraction and differences in the resolution of satellite and ground data. Here, we attempt to quantify the effect of these factors by relating L-band ALOS PALSAR HV backscatter and unique country-wide LiDAR-derived maps of vegetation penetrability, height and AGB over Denmark at different spatial scales (50 m to 500 m. Trends in the relations indicate that, first, AGB retrieval accuracy from SAR improves most in mapping at 100-m scale instead of 50 m, and improvements are negligible beyond 250 m. Relative errors (bias and root mean squared error decrease particularly for high AGB values (\\(>\\110 Mg ha\\(^{-1}\\ at coarse scales, and hence, coarse-scale mapping (\\(\\ge\\150 m may be most suited for areas with high AGB. Second, SAR backscatter and a LiDAR-derived measure of fractional forest cover were found to have a strong linear relation (R\\(^2\\ = 0.79 at 250-m scale. In areas of high fractional forest cover, there is a slight decline in backscatter as AGB increases, indicating signal attenuation. The two results demonstrate that accounting for spatial scale and variations in forest structure, such as cover fraction, will greatly benefit establishing adequate plot-sizes for SAR calibration and the accuracy of derived AGB maps.

  13. Development and Validation of a Short-Form Adaptation of the Age-Related Vision Loss Scale: The AVL12 (United States)

    Horowitz, Amy; Reinhardt, Joann P.; Raykov, Tenko


    This article describes the development and evaluation of a short form of the 24-item Adaptation to Age-Related Vision Loss (AVL) scale. The evaluation provided evidence of the reliability and validity of the short form (the AVL12), for significant interindividual differences at the baseline and for individual-level change in AVL scores over time.…

  14. Quantitative Assessment of Autism Symptom-Related Traits in Probands and Parents: Broader Phenotype Autism Symptom Scale (United States)

    Dawson, Geraldine; Estes, Annette; Munson, Jeffrey; Schellenberg, Gerard; Bernier, Raphael; Abbott, Robert


    Autism susceptibility genes likely have effects on continuously distributed autism-related traits, yet few measures of such traits exist. The Broader Phenotype Autism Symptom Scale (BPASS), developed for use with affected children and family members, measures social motivation, social expressiveness, conversational skills, and flexibility. Based…

  15. Two micro-models of tourism capitalism and the (re)scaling of state-business relations

    NARCIS (Netherlands)

    Erkuş-Öztürk, H.; Terhorst, P.


    This paper aims to show that (i) there are two micro-models of tourism capitalism in Antalya (Turkey) and (ii) different trajectories of (re)scaling of state-business relations form an integral part of each model of tourism capitalism. The paper bridges two debates in the literature that generally

  16. Performed and perceived walking ability in relation to the Expanded Disability Status Scale in persons with multiple sclerosis

    DEFF Research Database (Denmark)

    Langeskov-Christensen, D; Feys, P; Baert, I


    BACKGROUND: The severity of walking impairment in persons with multiple sclerosis (pwMS) at different levels on the expanded disability status scale (EDSS) is unclear. Furthermore, it is unclear if the EDSS is differently related to performed- and perceived walking capacity tests. AIMS: To quantify...

  17. Scaling approach to related disordered stochastic and free-fermion models (United States)

    Harris, R. J.; Stinchcombe, R. B.


    Motivated by mapping from a stochastic system with spatially random rates, we consider disordered nonconserving free-fermion systems using a scaling procedure for the equations of motion. This approach demonstrates disorder-induced localization acting in competition with the asymmetric driving. We discuss the resulting implications for the original stochastic system.

  18. Relation between B-mode Gray-scale Median and Clinical Features of Carotid Stenosis Vulnerability

    NARCIS (Netherlands)

    Kolkert, Joe L.; Meerwaldt, Robbert; Loonstra, Jan; Schenk, Miranda; van der Palen, Job; van den Dungen, Jan J.; Zeebregts, Clark J.

    Background: Vulnerability of the carotid plaque might be useful as a predictor for ischemic stroke risk. The gray-scale median (GSM) of the carotid plaque at B-mode imaging has been described as an objective tool to quantify vulnerability. However, its use is disputed in the published literature.

  19. Relation between B-mode Gray-scale Median and Clinical Features of Carotid Stenosis Vulnerability

    NARCIS (Netherlands)

    Kolkert, Joé L.; Meerwaldt, Robbert; Loonstra, Jan; Schenk, Miranda; van der Palen, Jacobus Adrianus Maria; van den Dungen, Jan J.; Zeebregts, Clark J.


    Background Vulnerability of the carotid plaque might be useful as a predictor for ischemic stroke risk. The gray-scale median (GSM) of the carotid plaque at B-mode imaging has been described as an objective tool to quantify vulnerability. However, its use is disputed in the published literature.

  20. Factor Structure of the Rorschach Prognostic Rating Scale and Its Relation to Therapeutic Outcome (United States)

    Auerbach, Stephen M.; Edinger, Jack D.


    This study evaluated the factor structure of the Rorschach Prognostic Rating Scale (RPRS) in order to: (a) test the assumption that the RPRS represents a unitary response system and (b) determine the efficacy of employing population specific factor scores as predictors of therapy outcome. (Author/NG)

  1. Theoretical and Numerical Properties of a Gyrokinetic Plasma: Issues Related to Transport Time Scale Simulation

    Energy Technology Data Exchange (ETDEWEB)

    W.W. Lee


    Particle simulation has played an important role for the recent investigations on turbulence in magnetically confined plasmas. In this paper, theoretical and numerical properties of a gyrokinetic plasma as well as its relationship with magnetohydrodynamics (MHD) are discussed with the ultimate aim of simulating microturbulence in transport time scale using massively parallel computers.

  2. Scaling analysis of self-assembled structures and related morphological information in epitaxial growth (United States)

    Blel, Sonia; Hamouda, Ajmi B. H.; Mahjoub, Brahim; Hoggan, Philip; Oujia, Brahim


    Using kinetic Monte-Carlo simulations, we have performed a qualitative and quantitative study of the homo-epitaxial growth for two materials Cu and Ag. Based on their dynamic scaling properties, a relationship between the resultant growth morphology and its computed scaling exponents is found to play a key role in the surface self-assembled at long time (hundreds of monolayer) and also at early time (sub-monolayer regime) of growth. Then, the effect of next-nearest-neighbor (NNN) interactions on the scaling exponents, as well as the surface morphology, is discussed. NNN interactions are found to affect the scaling exponents in the case of Cu rather than Ag. We also show that the higher the local roughness, the best 1-D nanostructures are obtained; which is confirmed by the measurement of filling rate of nanowires at step-edge on vicinal surfaces. Our results were compared to the available experimental and theoretical results and seem advantageous for a better understanding of the growth dynamics.

  3. Decision trees to characterise the roles of permeability and solubility on the prediction of oral absorption. (United States)

    Newby, Danielle; Freitas, Alex A; Ghafourian, Taravat


    Oral absorption of compounds depends on many physiological, physiochemical and formulation factors. Two important properties that govern oral absorption are in vitro permeability and solubility, which are commonly used as indicators of human intestinal absorption. Despite this, the nature and exact characteristics of the relationship between these parameters are not well understood. In this study a large dataset of human intestinal absorption was collated along with in vitro permeability, aqueous solubility, melting point, and maximum dose for the same compounds. The dataset allowed a permeability threshold to be established objectively to predict high or low intestinal absorption. Using this permeability threshold, classification decision trees incorporating a solubility-related parameter such as experimental or predicted solubility, or the melting point based absorption potential (MPbAP), along with structural molecular descriptors were developed and validated to predict oral absorption class. The decision trees were able to determine the individual roles of permeability and solubility in oral absorption process. Poorly permeable compounds with high solubility show low intestinal absorption, whereas poorly water soluble compounds with high or low permeability may have high intestinal absorption provided that they have certain molecular characteristics such as a small polar surface or specific topology. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  4. Research on red cell membrane permeability in arterial hypertension. (United States)

    Gatina, R; Balta, N; Moisin, C; Burtea, C; Botea, S; Ioan, M; Teleianu, C


    Arterial hypertension, including the elucidation of hypertension pathogenic mechanisms involving elements in the composition of the blood, continues to represent a topical research area. Recent work, such as nuclear magnetic resonance studies looking into red cell permeability, illustrates the presence of modifications of red cell permeability to water (RCPW) related to the stage of arterial hypertension. The identification of a significant increase of RCPW compared to that present in the population with normal arterial pressure values can be useful both in early diagnosis and in warning about a possible predisposition for this condition. At the same time, the dynamic investigation of protonic relaxation time of both intra- and extra-erythrocytic water, the assessment of proton exchange time across the red cell and the calculation of permeability to water enable one not only to diagnose arterial hypertension but also to ascertain the evolution of the disease, its complications and the effectiveness of anti-hypertensive medication. Our studies have also proven the existence of a correlation between the values of systolic arterial pressure and red cell permeability to water. The curve describing the interdependence of the two values has the shape of a bell, in the case of males. The peak of the curve is reached for a systolic pressure of 160 mmHg and gets below the values of the control group in the case of systolic pressures above 200 mmHg. The RCPW test can also be considered a valuable indicator in evaluating the risk of stroke in hypertensive patients. In the chronic therapy of arterial hypertension with various types of anti-hypertensive drugs, one can note differences in the RCPW values related to the effectiveness of the respective medication, to the clinical form and stage of the disease, the sex of the patient as well as to the existence of cerebro-vascular complications.

  5. Development and preliminary testing of a scale to assess pain-related fear in children and adolescents. (United States)

    Huguet, Anna; McGrath, Patrick J; Pardos, Judit


    It is assumed that pain-related fear, a present response to an immediate danger or threat such as pain, plays a significant role in the experience of pediatric pain. However, there are no measures to adequately measure this construct in children and adolescents. The purpose of this study was to develop and test the psychometric properties of a scale to assess pain-related fear to be used with Catalan-speaking children and adolescents between 7- and 16-years-old. We initially developed a list of items that reflected the physiological, cognitive, and behavioral components of pain-related fear components. We also queried an international group of experts, and interviewed children and adolescents. After pilot testing the initial version with a sample of 10 children, we administered the questionnaire to a sample of schoolchildren (n = 273) and children from medical clinics (n = 164) through individual interviews. Additional information was also collected during the interview to study the psychometric properties of the scale. Ten days after the initial interview, participating schoolchildren were requested to answer the questionnaire again. Item analysis and exploratory factor analysis with data from the school sample produced 2 meaningful factors (namely, Fearful thoughts and Fearful physical feelings and behaviors). Findings also showed that the Pediatric Pain Fear Scale (total scale and the 2 subscales) was both reliable and valid. This scale could help researchers to gain a better understanding about the role of pain-related fear in children and adolescents and support clinical decision-making. This article presents a new measure of fear associated with pain in children and adolescents. This measure could potentially help researchers to gain a better understanding about the role of pain-related fear in children and adolescents and support clinical decision-making. Copyright © 2011 American Pain Society. Published by Elsevier Inc. All rights reserved.

  6. Gas permeability of lanthanum oxycarbide targets for the SPES project

    Energy Technology Data Exchange (ETDEWEB)

    Biasetto, L., E-mail: [Università di Padova-Department DTG, Stradella San Nicola 3, I-36100 Vicenza (Italy); Laboratori Nazionali di Legnaro-INFN, V.le dell’Università 2, I-35020 Legnaro (PD) (Italy); Innocentini, M.D.M.; Chacon, W.S. [Curso de Engenharia Química, Universidade de Ribeirão Preto, 14096-900 Ribeirão Preto, SP (Brazil); Corradetti, S.; Carturan, S. [Laboratori Nazionali di Legnaro-INFN, V.le dell’Università 2, I-35020 Legnaro (PD) (Italy); Colombo, P. [Università di Padova, Department DII, via Marzolo 9, I-35131 Padova (Italy); Department of Materials Science and Engineering, The Pennsylvania State University, University Park, PA 16802 (United States); Andrighetto, A. [Laboratori Nazionali di Legnaro-INFN, V.le dell’Università 2, I-35020 Legnaro (PD) (Italy)


    The creation of a porous matrix made of interconnected and permeable paths is a key step for the processing of optimized metal carbide targets in the SPES (Selective Production of Exotic Species) project. Unlike close or non-connected open pores, permeable pores link more efficiently the interior and the surface of target disks, and therefore facilitate the effusion and convection transport mechanisms for a faster extraction of exotic nuclei with short decay times. This work describes the analysis of the interconnected porosity of lanthanum oxycarbide targets through the evaluation of permeability coefficients obtained in argon flow experiments at room and high temperature. Samples were produced by the sacrificial template method using phenolic resin (PR) as source of carbon for the carbothermal reaction of lanthanum oxide, and different amounts of polymethilmetacrylate (PMMA) microbeads as template for the production of porosity. Results showed that conventional targets prepared without sacrificial templates displayed relatively high total porosity (45.6%), but very low permeability coefficients (k{sub 1} = 4.21 × 10{sup −17} m{sup 2} and k{sub 2} = 1.90 × 10{sup −15} m), comparable to other dense ceramic materials. The linear increase in total porosity from 64.8% to 88.9% achieved by the gradual increase of PMMA from 30% to 80 wt.% resulted in a remarkable increase of five orders of magnitude for k{sub 1} (2.36 × 10{sup −12} m{sup 2}) and eight orders for k{sub 2} (7.48 × 10{sup −7} m{sup 2}). The addition of sacrificial fillers was found to be much more efficient to create interconnected and permeable paths in the structure than the carbothermal reduction itself. Preliminary tests with argon flow up to 450 °C revealed that the porous matrix also became more permeable with the increase in the gas temperature due to thermal expansion effects, but the extent of this gain depended on the initial porosity level of the sample.

  7. Criterion-related validity of perceived exertion scales in healthy children: a systematic review and meta-analysis. (United States)

    Rodríguez, Iván; Zambrano, Lysien; Manterola, Carlos


    Physiological parameters used to measure exercise intensity are oxygen uptake and heart rate. However, perceived exertion (PE) is a scale that has also been frequently applied. The objective of this study is to establish the criterion-related validity of PE scales in children during an incremental exercise test. Seven electronic databases were used. Studies aimed at assessing criterion-related validity of PE scales in healthy children during an incremental exercise test were included. Correlation coefficients were transformed into z-values and assessed in a meta-analysis by means of a fixed effects model if I2 was below 50% or a random effects model, if it was above 50%. wenty-five articles that studied 1418 children (boys: 49.2%) met the inclusion criteria. Children's average age was 10.5 years old. Exercise modalities included bike, running and stepping exercises. The weighted correlation coefficient was 0.835 (95% confidence interval: 0.762-0.887) and 0.874 (95% confidence interval: 0.794-0.924) for heart rate and oxygen uptake as reference criteria. The production paradigm and scales that had not been adapted to children showed the lowest measurement performance (p valid in healthy children during an incremental exercise test. Child-specific rating scales showed a better performance than those that had not been adapted to this population. Further studies with better methodological quality should be conducted in order to confirm these results. Sociedad Argentina de Pediatría.

  8. Scale-location specific relations between soil nutrients and topographic factors in the Fen River Basin, Chinese Loess Plateau (United States)

    Zhu, Hongfen; Bi, Rutian; Duan, Yonghong; Xu, Zhanjun


    Understanding scale- and location-specific variations of soil nutrients in cultivated land is a crucial consideration for managing agriculture and natural resources effectively. In the present study, wavelet coherency was used to reveal the scale-location specific correlations between soil nutrients, including soil organic matter (SOM), total nitrogen (TN), available phosphorus (AP), and available potassium (AK), as well as topographic factors (elevation, slope, aspect, and wetness index) in the cultivated land of the Fen River Basin in Shanxi Province, China. The results showed that SOM, TN, AP, and AK were significantly inter-correlated, and that the scales at which soil nutrients were correlated differed in different landscapes, and were generally smaller in topographically rougher terrain. All soil nutrients but TN were significantly influenced by the wetness index at relatively large scales (32-72 km) and AK was significantly affected by the aspect at large scales at partial locations, showing localized features. The results of this study imply that the wetness index should be taken into account during farming practices to improve the soil nutrients of cultivated land in the Fen River Basin at large scales.

  9. Gastrointestinal permeability in patients with irritable bowel syndrome assessed using a four probe permeability solution (United States)

    Del Valle-Pinero, Arseima Y.; Van Deventer, Hendrick E.; Fourie, Nicolaas H.; Martino, Angela C.; Patel, Nayan S.; Remaley, Alan T.; Henderson, Wendy A.


    Background Abnormal gastrointestinal permeability has been linked to irritable bowel syndrome (IBS). The lactulose-to-mannitol ratio is traditionally used to assess small intestine permeability while sucralose and sucrose are used to assess colonic and gastric permeability respectively. We used a single 4-probe test solution to assess permeability throughout the gastrointestinal tract in IBS patients and healthy controls by measuring the recovery of the probes in urine after ingestion using a modified liquid chromatography mass spectrometry protocol. Methods Fasting participants (N = 59) drank a permeability test solution (100 ml: sucralose, sucrose, mannitol, and lactulose). Urine was collected over a 5-h period and kept frozen until analysis. Urinary sugar concentrations were measured using an liquid chromatography/triple quadruple mass spectrometer. Results Colonic permeability was significantly lower in IBS patients when compared to healthy controls (p = 0.011). Gastric and small intestinal permeability did not significantly differ between the groups. Conclusions The study demonstrates the clinical potential of this non-invasive method for assessing alterations in gastrointestinal permeability in patients with IBS. PMID:23328210

  10. Validation of an HIV-related stigma scale among health care providers in a resource-poor Ethiopian setting

    Directory of Open Access Journals (Sweden)

    Feyissa GT


    Full Text Available Garumma Tolu Feyissa1, Lakew Abebe1, Eshetu Girma1, Mirkuzie Woldie21Department of Health Education and Behavioral Sciences, 2Department of Health Services Management, Jimma University, Jimma, EthiopiaBackground: Stigma and discrimination (SAD against people living with human immunodeficiency virus (HIV are barriers affecting effective responses to HIV. Understanding the causes and extent of SAD requires the use of a psychometrically reliable and valid scale. The objective of this study was to validate an HIV-related stigma scale among health care providers in a resource-poor setting.Methods: A cross-sectional validation study was conducted in 18 health care institutions in southwest Ethiopia, from March 14, 2011 to April 14, 2011. A total of 255 health care providers responded to questionnaires asking about sociodemographic characteristics, HIV knowledge, perceived institutional support (PIS and HIV-related SAD. Exploratory factor analysis (EFA with principal component extraction and varimax with Kaiser normalization rotation were employed to develop scales for SAD. Eigenvalues greater than 1 were used as a criterion of extraction. Items with item-factor loadings less than 0.4 and items loading onto more than one factor were dropped. The convergent validity of the scales was tested by assessing the association with HIV knowledge, PIS, training on topics related to SAD, educational status, HIV case load, presence of an antiretroviral therapy (ART service in the health care facility, and perceived religiosity.Results: Seven factors emerged from the four dimensions of SAD during the EFA. The factor loadings of the items ranged from 0.58 to 0.93. Cronbach's alphas of the scales ranged from 0.80 to 0.95. An in-depth knowledge of HIV, perceptions of institutional support, attendance of training on topics related to SAD, degree or higher education levels, high HIV case loads, the availability of ART in the health care facility and claiming oneself as

  11. Third invitational well-testing symposium: well testing in low permeability environments

    Energy Technology Data Exchange (ETDEWEB)

    Doe, T.W.; Schwarz, W.J. (eds.)


    The testing of low permeability rocks is common to waste disposal, fossil energy resource development, underground excavation, and geothermal energy development. This document includes twenty-six papers and abstracts, divided into the following sessions: opening session, case histories and related phenomena, well test design in low permeability formations, analysis and interpretation of well test data, and instrumentation for well tests. Separate abstracts were prepared for 15 of the 16 papers; the remaining paper has been previously abstracted. (DLC)

  12. Age-related changes in the plasticity and toughness of human cortical bone at multiple length-scales

    Energy Technology Data Exchange (ETDEWEB)

    Zimmermann, Elizabeth A.; Schaible, Eric; Bale, Hrishikesh; Barth, Holly D.; Tang, Simon Y.; Reichert, Peter; Busse, Bjoern; Alliston, Tamara; Ager III, Joel W.; Ritchie, Robert O.


    The structure of human cortical bone evolves over multiple length-scales from its basic constituents of collagen and hydroxyapatite at the nanoscale to osteonal structures at nearmillimeter dimensions, which all provide the basis for its mechanical properties. To resist fracture, bone’s toughness is derived intrinsically through plasticity (e.g., fibrillar sliding) at structural-scales typically below a micron and extrinsically (i.e., during crack growth) through mechanisms (e.g., crack deflection/bridging) generated at larger structural-scales. Biological factors such as aging lead to a markedly increased fracture risk, which is often associated with an age-related loss in bone mass (bone quantity). However, we find that age-related structural changes can significantly degrade the fracture resistance (bone quality) over multiple lengthscales. Using in situ small-/wide-angle x-ray scattering/diffraction to characterize sub-micron structural changes and synchrotron x-ray computed tomography and in situ fracture-toughness measurements in the scanning electron microscope to characterize effects at micron-scales, we show how these age-related structural changes at differing size-scales degrade both the intrinsic and extrinsic toughness of bone. Specifically, we attribute the loss in toughness to increased non-enzymatic collagen cross-linking which suppresses plasticity at nanoscale dimensions and to an increased osteonal density which limits the potency of crack-bridging mechanisms at micron-scales. The link between these processes is that the increased stiffness of the cross-linked collagen requires energy to be absorbed by “plastic” deformation at higher structural levels, which occurs by the process of microcracking.

  13. Coexistence of sympatric carnivores in relatively homogeneous Mediterranean landscapes: functional importance of habitat segregation at the fine-scale level. (United States)

    Soto, Carolina; Palomares, Francisco


    One of the main objectives of community ecology is to understand the conditions allowing species to coexist. However, few studies have investigated the role of fine-scale habitat use segregation in the functioning of guild communities in relatively homogeneous landscapes where opportunities for coexistence are likely to be the most restrictive. We investigate how the process of habitat use differentiation at the home range level according to the degree of specialism/generalism of species can lead to coexistence between guild species. We examine differences in fine-scale habitat use and niche separation as potential mechanisms explaining the coexistence of five sympatric carnivore species that differ in life history traits (Iberian lynx, Eurasian badger, Egyptian mongoose, common genet and red fox) by collecting data from systematic track censuses in a relatively homogeneous Mediterranean landscape. We found that a higher degree of specialism determines the segregation of species among the fine-scale ecological niche dimensions defined using quantitative elements associated with vegetation, landscape, prey availability and human disturbance. The species with the lowest total performance over the set of variables did not exhibit segregation in the use of habitat at this level. Our study indicates that in relatively homogeneous landscapes, there exist subtle patterns of habitat partitioning over small-scale gradients of habitat determinants as a function of the degree of specialism of carnivore species within a guild. Our results also suggest that coexistence between generalist species may be permitted by fine-scale spatial-temporal segregation of activity patterns or trophic resource consumption, but not fine-scale habitat use differentiation.

  14. Vascular permeability alterations induced by arsenic. (United States)

    Chen, Shih-Chieh; Tsai, Ming-Hsien; Wang, Hsiu-Jen; Yu, Hsin-Su; Chang, Louis W


    The impact of arsenic on the integrity of blood vessels in vivo via in situ exposure (local injection) of arsenic was investigated. Vascular permeability changes were evaluated by means of the Evans blue assay and the India ink tracer techniques. Rats were intravenously injected with Evans blue followed by intradermal injections of various doses of sodium arsenite on the back skins of the animals. Evans blue at different time points was extracted and assayed as indices of vascular leakage. Skin at various time point injection sites was sampled for arsenic measurement via graphite furnace atomic absorption spectroscopy. Our time course study with Evans blue technique demonstrated a biphasic pattern of vascular permeability change: an early phase of permeability reduction and a later phase of permeability promotion at all dose levels tested. The India ink tracer technique also demonstrated a time-correlated increase in vascular labelling in the tissues examined, signifying an increase in vascular leakage with time. Moreover, we found that despite an early increase in tissue arsenic content at time of injection, tissue arsenic declined rapidly and returned to near control levels after 30-60 min. Thus, an inverse correlation between tissue arsenic content and the extent of vascular permeability was apparent. This study provides the first demonstration that in situ exposure to arsenic will produce vascular dysfunction (vascular leakage) in vivo.

  15. Changes in permeability caused by earthquakes (United States)

    Manga, Michael; Wang, Chi-Yuen; Shi, Zheming


    Earthquakes induce a range of hydrological responses, including changes in streamflow and changes in the water level in wells. Here we show that many of these responses are caused the changes in permeability produced by the passage of seismic waves. First we analyze streams that were dry or nearly dry before the 2014 M6 Napa, California, earthquake butstarted to flow after the earthquake. We show that the new flows were meteoric in origin and originate in the nearby mountains. Responses are not correlated with the sign of static strains implying seismic waves liberated this water, presumably by changing permeability. We also analyze a large network of wells in China that responded to 4 large earthquakes. We monitor permeability changes through their effect on the water level response to solid Earth tides. We find that when earthquakes produce sustained changes in water level, permeability also changes. Wells with water level changes that last for only days show no evidence for changes in aquifer permeability.

  16. Water permeability and characterization of aquaporin-11. (United States)

    Yakata, Kaya; Tani, Kazutoshi; Fujiyoshi, Yoshinori


    The water permeability of aquaporin-11 (AQP11), which has a cysteine substituted for an alanine at a highly conserved asparagine-proline-alanine (NPA) motif in the water channel family, is controversial. Our previous study, however, showed that AQP11 is water permeable in proteoliposomes in which AQP11 molecules were reconstituted after purification with Fos-choline 10, which is the most suitable detergent available for stable solubilization of AQP11. In our previous study, we were unable to exclude the effect of the detergent on the water conductance. Therefore, in the present study, we measured the water permeability of AQP11 without detergent using vesicles that directly formed from Sf9 cell membranes expressing AQP11 molecules. The water permeability of AQP11 was 8-fold lower than that of AQP1 and 3-fold higher than that of mock-infected cell membrane, and was reversibly inhibited by mercury ions. Considering the slow but constant water permeable functions of AQP11, we performed homology modeling to search for a common structural feature. When comparing our model with those of other AQP structures, we found that Tyr83 facing the channel pore might be a key amino acid residue that decreases the water permeation of AQP11. Our findings indicate that AQP11 could be involved in slow but constant water movement across the membrane. Copyright © 2011 Elsevier Inc. All rights reserved.

  17. Experimental constraints on degassin