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Sample records for w-k-m double wedge

  1. Stem thrust prediction model for W-K-M double wedge parallel expanding gate valves

    Energy Technology Data Exchange (ETDEWEB)

    Eldiwany, B.; Alvarez, P.D. [Kalsi Engineering Inc., Sugar Land, TX (United States); Wolfe, K. [Electric Power Research Institute, Palo Alto, CA (United States)

    1996-12-01

    An analytical model for determining the required valve stem thrust during opening and closing strokes of W-K-M parallel expanding gate valves was developed as part of the EPRI Motor-Operated Valve Performance Prediction Methodology (EPRI MOV PPM) Program. The model was validated against measured stem thrust data obtained from in-situ testing of three W-K-M valves. Model predictions show favorable, bounding agreement with the measured data for valves with Stellite 6 hardfacing on the disks and seat rings for water flow in the preferred flow direction (gate downstream). The maximum required thrust to open and to close the valve (excluding wedging and unwedging forces) occurs at a slightly open position and not at the fully closed position. In the nonpreferred flow direction, the model shows that premature wedging can occur during {Delta}P closure strokes even when the coefficients of friction at different sliding surfaces are within the typical range. This paper summarizes the model description and comparison against test data.

  2. Aerodynamic Analysis Over Double Wedge Airfoil

    Science.gov (United States)

    Prasad, U. S.; Ajay, V. S.; Rajat, R. H.; Samanyu, S.

    2017-05-01

    Aeronautical studies are being focused more towards supersonic flights and methods to attain a better and safer flight with highest possible performance. Aerodynamic analysis is part of the whole procedure, which includes focusing on airfoil shapes which will permit sustained flight of aircraft at these speeds. Airfoil shapes differ based on the applications, hence the airfoil shapes considered for supersonic speeds are different from the ones considered for Subsonic. The present work is based on the effects of change in physical parameter for the Double wedge airfoil. Mach number range taken is for transonic and supersonic. Physical parameters considered for the Double wedge case with wedge angle (ranging from 5 degree to 15 degree. Available Computational tools are utilized for analysis. Double wedge airfoil is analysed at different Angles of attack (AOA) based on the wedge angle. Analysis is carried out using fluent at standard conditions with specific heat ratio taken as 1.4. Manual calculations for oblique shock properties are calculated with the help of Microsoft excel. MATLAB is used to form a code for obtaining shock angle with Mach number and wedge angle at the given parameters. Results obtained from manual calculations and fluent analysis are cross checked.

  3. The role of aerothermochemistry in double cone and double wedge flows

    Science.gov (United States)

    Swantek, Andrew

    In this work, hypervelocity flows over double cone and double wedge geometries are studied. The flow configurations established over the double cone/double wedge models are extremely sensitive to thermochemistry, and thus serve as ideal benchmarks for validating chemical models. The goals of this research are: i) to investigate the coupling between the fluid mechanics and thermochemistry in these flow fields by varying freestream flow composition and enthalpy, ii) to implement a diagnostic suite for time-resolved surface and freestream measurements, iii) to investigate the nature of flow field unsteadiness across various test conditions, and lastly iv) to extend the experimental database for shock wave boundary/layer interactions. An expansion tube is used to generate flows with enthalpies ranging from 2.2-8.0 MJ/kg (2-4 km/s) and Mach numbers from 4-7. The expansion tube is a novel impulse facility for accelerating a test gas to these velocities, while maintaining a minimally dissociated freestream. Additionally, the facility allows variation of the freestream composition (between nitrogen and air), while maintaining freestream test parameters (Mach number, density, enthalpy) to within 0.5%. Two models are used: a 25-55 degree double cone model and a 30-55 degree double wedge. There are four diagnostic components to this research which aim to enable a better understanding of these canonical flow fields. Single frame, high resolution schlieren photography is used to visualize various flow features including: the separation zone formed in the corner, the triple point interaction, and a supersonic shear layer. From these images, a separation zone length scaling parameter is determined. This parameter, derived for wedge geometries, is successfully applied to conical geometries by using a judicious choice of flow properties for scaling. In the wedge image series, nitrogen test conditions exhibit a distinct increase in bow shock standoff distance. Additionally, aft

  4. Generation of vector beams using a double-wedge depolarizer: Non-quantum entanglement

    Science.gov (United States)

    Samlan, C. T.; Viswanathan, Nirmal K.

    2016-07-01

    Propagation of horizontally polarized Gaussian beam through a double-wedge depolarizer generates vector beams with spatially varying state of polarization. Jones calculus is used to show that such beams are maximally nonseparable on the basis of even (Gaussian)-odd (Hermite-Gaussian) mode parity and horizontal-vertical polarization state. The maximum nonseparability in the two degrees of freedom of the vector beam at the double wedge depolarizer output is verified experimentally using a modified Sagnac interferometer and linear analyser projected interferograms to measure the concurrence 0.94±0.002 and violation of Clauser-Horne-Shimony-Holt form of Bell-like inequality 2.704±0.024. The investigation is carried out in the context of the use of vector beams for metrological applications.

  5. NUMERICAL MODELING AND DYNAMIC SIMULATIONS OF NONLINEAR AEROTHERMOELASTIC OF A DOUBLE-WEDGE LIFTING SURFACE

    Directory of Open Access Journals (Sweden)

    ARIF A. EBRAHEEM AL-QASSAR

    2008-12-01

    Full Text Available The design of the re-entry space vehicles and high-speed aircrafts requires special attention to the nonlinear thermoelastic and aerodynamic instabilities of their structural components. The thermal effects are important since temperature environment influences significantly the static and dynamic behaviors of flight structures in supersonic/hypersonic regimes. To contribute to the understanding of dynamic behavior of these “hot” structures, a double-wedge lifting surface with combined freeplay and cubic stiffening structural nonlinearities in both plunging and pitching degrees-of-freedom operating in supersonic/hypersonic flight speed regimes has been analyzed. A third order Piston Theory Aerodynamics is used to evaluate the applied nonlinear unsteady aerodynamic loads. The loss of torsional stiffness that may be incurred by lifting surfaces subjected to axial stresses induced by aerodynamic heating is also considered. The aerodynamic heating effect is estimated based on the adiabatic wall temperature due to high speed airstreams. Modelling issues as well as simulation results have been presented and pertinent conclusions outlined. It is highlighted that a serious loss of torsional stiffness may induce the dynamic instability of the lifting surfaces. The influence of various parameters such as flight condition, thickness ratio, freeplays and pitching stiffness nonlinearity are also discussed.

  6. Fake Wedges

    OpenAIRE

    Klein, John R.; Peter, John W.

    2012-01-01

    A fake wedge is a diagram of spaces K C whose double mapping cylinder is contractible. The terminology stems from the special case A = K v C with maps given by the projections. In this paper, we study the homotopy type of the moduli space D(K,C) of fake wedges on K and C. We formulate two conjectures concerning this moduli space and verify that these conjectures hold after looping once. We show how embeddings of manifolds in Euclidean space provide a wealth of examples of non-trivial fake we...

  7. Effects of laterally wedged insoles on symptoms and disease progression in medial knee osteoarthritis: a protocol for a randomised, double-blind, placebo controlled trial

    Directory of Open Access Journals (Sweden)

    Osborne Richard

    2007-09-01

    Full Text Available Abstract Background Whilst laterally wedged insoles, worn inside the shoes, are advocated as a simple, inexpensive, non-toxic self-administered intervention for knee osteoarthritis (OA, there is currently limited evidence to support their use. The aim of this randomised, double-blind controlled trial is to determine whether laterally wedges insoles lead to greater improvements in knee pain, physical function and health-related quality of life, and slower structural disease progression as well as being more cost-effective, than control flat insoles in people with medial knee OA. Methods/Design Two hundred participants with painful radiographic medial knee OA and varus malalignment will be recruited from the community and randomly allocated to lateral wedge or control insole groups using concealed allocation. Participants will be blinded as to which insole is considered therapeutic. Blinded follow up assessment will be conducted at 12 months after randomisation. The outcome measures are valid and reliable measures recommended for OA clinical trials. Questionnaires will assess changes in pain, physical function and health-related quality-of-life. Magnetic resonance imaging will measure changes in tibial cartilage volume. To evaluate cost-effectiveness, participants will record the use of all health-related treatments in a log-book returned to the assessor on a monthly basis. To test the effect of the intervention using an intention-to-treat analysis, linear regression modelling will be applied adjusting for baseline outcome values and other demographic characteristics. Discussion Results from this trial will contribute to the evidence regarding the effectiveness of laterally wedged insoles for the management of medial knee OA. Trial registration ACTR12605000503628; NCT00415259.

  8. Radial wedge flange clamp

    Science.gov (United States)

    Smith, Karl H.

    2002-01-01

    A radial wedge flange clamp comprising a pair of flanges each comprising a plurality of peripheral flat wedge facets having flat wedge surfaces and opposed and mating flat surfaces attached to or otherwise engaged with two elements to be joined and including a series of generally U-shaped wedge clamps each having flat wedge interior surfaces and engaging one pair of said peripheral flat wedge facets. Each of said generally U-shaped wedge clamps has in its opposing extremities apertures for the tangential insertion of bolts to apply uniform radial force to said wedge clamps when assembled about said wedge segments.

  9. Rethinking wedges

    Science.gov (United States)

    Davis, Steven J.; Cao, Long; Caldeira, Ken; Hoffert, Martin I.

    2013-03-01

    Abstract Stabilizing CO2 emissions at current levels for fifty years is not consistent with either an atmospheric CO2 concentration below 500 ppm or global temperature increases below 2 °C. Accepting these targets, solving the climate problem requires that emissions peak and decline in the next few decades, and ultimately fall to near zero. Phasing out emissions over 50 years could be achieved by deploying on the order of 19 'wedges', each of which ramps up linearly over a period of 50 years to ultimately avoid 1 GtC y-1 of CO2 emissions. But this level of mitigation will require affordable carbon-free energy systems to be deployed at the scale of tens of terawatts. Any hope for such fundamental and disruptive transformation of the global energy system depends upon coordinated efforts to innovate, plan, and deploy new transportation and energy systems that can provide affordable energy at this scale without emitting CO2 to the atmosphere. 1. Introduction In 2004, Pacala and Socolow published a study in Science arguing that '[h]umanity can solve the carbon and climate problem in the first half of this century simply by scaling up what we already know how to do' [1]. Specifically, they presented 15 options for 'stabilization wedges' that would grow linearly from zero to 1 Gt of carbon emissions avoided per year (GtC y-1 1 Gt = 1012 kg) over 50 years. The solution to the carbon and climate problem, they asserted, was 'to deploy the technologies and/or lifestyle changes necessary to fill all seven wedges of the stabilization triangle'. They claimed this would offset the growth of emissions and put us on a trajectory to stabilize atmospheric CO2 concentration at 500 ppm if emissions decreased sharply in the second half of the 21st century. The wedge concept has proven popular as an analytical tool for considering the potential of different technologies to reduce CO2 emissions. In the years since the paper was published, it has been cited more than 400 times, and

  10. RR-MR transition of a Type V shock interaction in inviscid double-wedge flow with high-temperature gas effects

    Science.gov (United States)

    Xiong, W.; Li, J.; Zhu, Y.; Luo, X.

    2017-11-01

    The transition between regular reflection (RR) and Mach reflection (MR) of a Type V shock-shock interaction on a double-wedge geometry with non-equilibrium high-temperature gas effects is investigated theoretically and numerically. A modified shock polar method that involves thermochemical non-equilibrium processes is applied to calculate the theoretical critical angles of transition based on the detachment criterion and the von Neumann criterion. Two-dimensional inviscid numerical simulations are performed correspondingly to reveal the interactive wave patterns, the transition processes, and the critical transition angles. The theoretical and numerical results of the critical transition angles are compared, which shows evident disagreement, indicating that the transition mechanism between RR and MR of a Type V shock interaction is beyond the admissible scope of the classical theory. Numerical results show that the collisions of triple points of the Type V interaction cause the transition instead. Compared with the frozen counterpart, it is found that the high-temperature gas effects lead to a larger critical transition angle and a larger hysteresis interval.

  11. Wedged multilayer Laue lens

    Science.gov (United States)

    Conley, Ray; Liu, Chian; Qian, Jun; Kewish, Cameron M.; Macrander, Albert T.; Yan, Hanfei; Kang, Hyon Chol; Maser, Jörg; Stephenson, G. Brian

    2008-05-01

    A multilayer Laue lens (MLL) is an x-ray focusing optic fabricated from a multilayer structure consisting of thousands of layers of two different materials produced by thin-film deposition. The sequence of layer thicknesses is controlled to satisfy the Fresnel zone plate law and the multilayer is sectioned to form the optic. An improved MLL geometry can be created by growing each layer with an in-plane thickness gradient to form a wedge, so that every interface makes the correct angle with the incident beam for symmetric Bragg diffraction. The ultimate hard x-ray focusing performance of a wedged MLL has been predicted to be significantly better than that of a nonwedged MLL, giving subnanometer resolution with high efficiency. Here, we describe a method to deposit the multilayer structure needed for an ideal wedged MLL and report our initial deposition results to produce these structures.

  12. Octave spanning wedge dispersive mirrors with low dispersion oscillations.

    Science.gov (United States)

    Habel, Florian; Shirvanyan, Vage; Trubetskov, Michael; Burger, Christian; Sommer, Annkatrin; Kling, Matthias F; Schultze, Martin; Pervak, Vladimir

    2016-05-02

    A novel concept for octave spanning dispersive mirrors with low spectral dispersion oscillations is presented. The key element of the so-called wedge dispersive mirror is a slightly wedged layer which is coated on a specially optimized dispersive multilayer stack by a common sputter coating process. The group delay dispersion (GDD) of a pulse reflected on a wedge dispersive mirror is nearly free of oscillations. Fabricated mirrors with negative GDD demonstrate the compression of a pulse down to 3.8 fs as good as double angled mirrors optimized for the same bandwidth.

  13. Shock detachment from curved wedges

    Science.gov (United States)

    Mölder, S.

    2017-09-01

    Curved shock theory is used to show that the flow behind attached shocks on doubly curved wedges can have either positive or negative post-shock pressure gradients depending on the freestream Mach number, the wedge angle and the two wedge curvatures. Given enough wedge length, the flow near the leading edge can choke to force the shock to detach from the wedge. This local choking can preempt both the maximum deflection and the sonic criteria for shock detachment. Analytical predictions for detachment by local choking are supported by CFD results.

  14. Characterization of wedge waves propagating along wedge tips with defects.

    Science.gov (United States)

    Chen, Ming-I; Tesng, Seng-Po; Lo, Pei-Yuan; Yang, Che-Hua

    2018-01-01

    Wedge waves are guided acoustic waves propagating along the tip of a wedge with the energy tightly confined near the wedge. Anti-symmetric flexural (ASF) modes are wedge waves with their particle motion anti-symmetric with the apex mid-plane. This study investigates the behaviors of ASF modes propagation along wedge tips with perfect and imperfect rectangular defects. Numerical finite element simulations and experimental measurements using a laser ultrasound technique are employed to explore the behaviors of ASF modes interacting with defects. Complex reflections and transmissions involved with direct reflections and transmissions as well as the newly discovered mode conversions will be explored and quantified in numerical as well as experimental ways. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Sojourner at Wedge

    Science.gov (United States)

    1997-01-01

    This image, taken by the Imager for Mars Pathfinder (IMP) at the end of Sol 44, shows the Sojourner rover heading toward a rock called 'Shark.' Sojourner's left front wheel is jutting up against the side of Wedge, at left. The stowed Alpha Proton X-Ray Spectrometer (APXS) instrument can be seen on the rear on the rover.Mars Pathfinder is the second in NASA's Discovery program of low-cost spacecraft with highly focused science goals. The Jet Propulsion Laboratory, Pasadena, CA, developed and manages the Mars Pathfinder mission for NASA's Office of Space Science, Washington, D.C. The Imager for Mars Pathfinder (IMP) was developed by the University of Arizona Lunar and Planetary Laboratory under contract to JPL. Peter Smith is the Principal Investigator. JPL is a division of the California Institute of Technology (Caltech).

  16. Estimating Nielsen Numbers on Wedge Product Spaces

    Directory of Open Access Journals (Sweden)

    Kim Seung Won

    2007-01-01

    Full Text Available Let be a self-map of a finite polyhedron that is an aspherical wedge product space . In this paper, we estimate the Nielsen number of . In particular, we study some algebraic properties of the free products and then estimate Nielsen numbers on torus wedge surface with boundary, Klein bottle wedge surface with boundary, and torus wedge torus.

  17. Portal dosimetry in wedged beams

    NARCIS (Netherlands)

    Spreeuw, H.; Rozendaal, R.; Camargo, P.; Mans, A.; Wendling, M.; Olaciregui-Ruiz, I.; Sonke, J.J.; Herk, M. van; Mijnheer, B.

    2015-01-01

    Portal dosimetry using electronic portal imaging devices (EPIDs) is often applied to verify high-energy photon beam treatments. Due to the change in photon energy spectrum, the resulting dose values are, however, not very accurate in the case of wedged beams if the pixel-to-dose conversion for the

  18. Erosion controls transpressional wedge kinematics

    Science.gov (United States)

    Leever, K. A.; Oncken, O.

    2012-04-01

    High resolution digital image analysis of analogue tectonic models reveals that erosion strongly influences the kinematics of brittle transpressional wedges. In the basally-driven experimental setup with low-angle transpression (convergence angle of 20 degrees) and a homogeneous brittle rheology, a doubly vergent wedge develops above the linear basal velocity discontinuity. In the erosive case, the experiment is interrupted and the wedge topography fully removed at displacement increments of ~3/4 the model thickness. The experiments are observed by a stereo pair of high resolution CCD cameras and the incremental displacement field calculated by Digital Particle Image Velocimetry (DPIV). From this dataset, fault slip on individual fault segments - magnitude and angle on the horizontal plane relative to the fault trace - is extracted using the method of Leever et al. (2011). In the non-erosive case, after an initial stage of strain localization, the wedge experiences two transient stages of (1) oblique slip and (2) localized strain partitioning. In the second stage, the fault slip angle on the pro-shear(s) rotates by some 30 degrees from oblique to near-orthogonal. Kinematic steady state is attained in the third stage when a through-going central strike-slip zone develops above the basal velocity discontinuity. In this stage, strain is localized on two main faults (or fault zones) and fully partitioned between plate boundary-parallel displacement on the central strike-slip zone and near-orthogonal reverse faulting at the front (pro-side) of the wedge. The fault slip angle on newly formed pro-shears in this stage is stable at 60-65 degrees (see also Leever et al., 2011). In contrast, in the erosive case, slip remains more oblique on the pro-shears throughout the experiment and a separate central strike-slip zone does not form, i.e. strain partitioning does not fully develop. In addition, more faults are active simultaneously. Definition of stages is based on slip on

  19. Ultrasonic friction power during Al wire wedge-wedge bonding

    Science.gov (United States)

    Shah, A.; Gaul, H.; Schneider-Ramelow, M.; Reichl, H.; Mayer, M.; Zhou, Y.

    2009-07-01

    Al wire bonding, also called ultrasonic wedge-wedge bonding, is a microwelding process used extensively in the microelectronics industry for interconnections to integrated circuits. The bonding wire used is a 25μm diameter AlSi1 wire. A friction power model is used to derive the ultrasonic friction power during Al wire bonding. Auxiliary measurements include the current delivered to the ultrasonic transducer, the vibration amplitude of the bonding tool tip in free air, and the ultrasonic force acting on the bonding pad during the bond process. The ultrasonic force measurement is like a signature of the bond as it allows for a detailed insight into mechanisms during various phases of the process. It is measured using piezoresistive force microsensors integrated close to the Al bonding pad (Al-Al process) on a custom made test chip. A clear break-off in the force signal is observed, which is followed by a relatively constant force for a short duration. A large second harmonic content is observed, describing a nonsymmetric deviation of the signal wave form from the sinusoidal shape. This deviation might be due to the reduced geometrical symmetry of the wedge tool. For bonds made with typical process parameters, several characteristic values used in the friction power model are determined. The ultrasonic compliance of the bonding system is 2.66μm/N. A typical maximum value of the relative interfacial amplitude of ultrasonic friction is at least 222nm. The maximum interfacial friction power is at least 11.5mW, which is only about 4.8% of the total electrical power delivered to the ultrasonic generator.

  20. Geometry and kinematics of extensional structural wedges

    Science.gov (United States)

    Gui, Baoling; He, Dengfa; Zhang, Yongsheng; Sun, Yanpeng; Huang, Jingyi; Zhang, Wenjun

    2017-03-01

    Structural wedges in the compressive environment have been recognized and studied in different locations. However, extension structural wedges are less well-understood. Based on the normal fault-bend folding theory and inclined shear model, this paper quantitatively analyses deformations related to extensional structural wedges and builds a series of geometric models for them. An extensional structural wedge is a fault-block held by two or more normal faults, the action of which would fold its overlying strata. Extensional structural wedges of different shapes will lead to different deformation results for the overlying strata, and this paper illustrates both the triangular and quadrangular wedges and their related deformations. This paper also discusses differences between the extensional structural wedges and the normal fault-bend-folding. By analysing two seismic sections from Langfang-Gu'an Sag, East China, this paper provides two natural examples of the triangular and quadrangular extensional structural wedges, where the models can reasonably explain the overlying distinct highs and lows without obvious faults. The establishment of a geometric model of extensional structural wedges can provide reference and theoretical bases for future quantitative analysis of deformations in the extensional environment.

  1. Ice Particle Impacts on a Moving Wedge

    Science.gov (United States)

    Vargas, Mario; Struk, Peter M.; Kreeger, Richard E.; Palacios, Jose; Iyer, Kaushik A.; Gold, Robert E.

    2014-01-01

    This work presents the results of an experimental study of ice particle impacts on a moving wedge. The experiment was conducted in the Adverse Environment Rotor Test Stand (AERTS) facility located at Penn State University. The wedge was placed at the tip of a rotating blade. Ice particles shot from a pressure gun intercepted the moving wedge and impacted it at a location along its circular path. The upward velocity of the ice particles varied from 7 to 12 meters per second. Wedge velocities were varied from 0 to 120 meters per second. Wedge angles tested were 0 deg, 30 deg, 45 deg, and 60 deg. High speed imaging combined with backlighting captured the impact allowing observation of the effect of velocity and wedge angle on the impact and the post-impact fragment behavior. It was found that the pressure gun and the rotating wedge could be synchronized to consistently obtain ice particle impacts on the target wedge. It was observed that the number of fragments increase with the normal component of the impact velocity. Particle fragments ejected immediately after impact showed velocities higher than the impact velocity. The results followed the major qualitative features observed by other researchers for hailstone impacts, even though the reduced scale size of the particles used in the present experiment as compared to hailstones was 4:1.

  2. Use of Wedge Absorbers in MICE

    Energy Technology Data Exchange (ETDEWEB)

    Neuffer, D. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Summers, D. [Univ. of Mississippi, Oxford, MS (United States); Mohayai, T. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); IIT, Chicago, IL (United States); Snopok, P. [Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); IIT, Chicago, IL (United States); Rogers, C. [Science and Technology Facilities Council (STFC), Oxford (United Kingdom). Rutherford Appleton Lab. (RAL)

    2017-03-01

    Wedge absorbers are needed to obtain longitudinal cooling in ionization cooling. They also can be used to obtain emittance exchanges between longitudinal and transverse phase space. There can be large exchanges in emittance, even with single wedges. In the present note we explore the use of wedge absorbers in the MICE experiment to obtain transverse–longitudinal emittance exchanges within present and future operational conditions. The same wedge can be used to explore “direct” and “reverse” emittance exchange dynamics, where direct indicates a configuration that reduces momentum spread and reverse is a configuration that increases momentum spread. Analytical estimated and ICOOL and G4BeamLine simulations of the exchanges at MICE parameters are presented. Large exchanges can be obtained in both reverse and direct configurations.

  3. Semi-infinite wedges and vertex operators

    CERN Document Server

    Stern, E

    1995-01-01

    The level 1 highest weight modules of the quantum affine algebra U_q(\\widehat{\\frak{sl}}_n) can be described as spaces of certain semi-infinite wedges. Using a q-antisymmetrization procedure, these semi-infinite wedges can be realized inside an infinite tensor product of evaluation modules. This realization gives rise to simple descriptions of vertex operators and (up to a scalar function) their compositions.

  4. A Wedge Absorber Experiment at MICE

    Energy Technology Data Exchange (ETDEWEB)

    Neuffer, David [Fermilab; Mohayai, Tanaz [IIT, Chicago; Rogers, Chris [Rutherford; Snopok, Pavel [IIT, Chicago; Summers, Don [Mississippi U.

    2017-05-01

    Emittance exchange mediated by wedge absorbers is required for longitudinal ionization cooling and for final transverse emittance minimization for a muon collider. A wedge absorber within the MICE beam line could serve as a demonstration of the type of emittance exchange needed for 6-D cooling, including the configurations needed for muon colliders, as well as configurations for low-energy muon sources. Parameters for this test are explored in simulation and possible experimental configurations with simulated results are presented.

  5. Stability analysis for three-plane wedges

    Science.gov (United States)

    Tharp, Thomas M.

    Stability analysis for rock wedges bounded by three planar discontinuities is a time-consuming procedure usually carried out by stereographic projection. An algorithm is presented which identifies the behavior mode for wedges and calculates the factor of safety more accurately than is possible by graphical methods. The upper and lower hemisphere stereographic projections also are plotted. This is the standard presentation format and it allows a visual check of the influence of assumed geometries and friction angles.

  6. Turbulent wedge spreading dynamics and control strategies

    Science.gov (United States)

    Suryanarayanan, Saikishan; Goldstein, David; Brown, Garry

    2017-11-01

    Turbulent wedges are encountered in some routes to transition in wall bounded flows, particularly those involving surface roughness. They are characterized by strongly turbulent regions that are formed downstream of large disturbances, and spread into the non-turbulent flow. Altering the wedge spreading mechanism is a possible drag reduction strategy. Following recent studies of Goldstein, Chu and Brown (Flow Turbul. Combust. 98(1), 2017) and Kuester and White (Exp. Fluids 57(4), 2016), we explore the relation between the base flow vorticity field and turbulent wedge spreading using immersed boundary direct numerical simulations. The lateral spreading rate of the wedges are similar for high Reynolds number boundary layers and Couette flow, but differences emerge in wall normal propagation of turbulence. We also attempt to utilize the surface texture based strategy suggested by Strand and Goldstein (J. Fluid Mech. 668, 2011) to reduce the spreading of isolated turbulent spots, for turbulent wedge control. The effects of height, spacing and orientation of fins on the dynamics of wedge evolution are studied. The results are interpreted from a vorticity dynamics point of view. Supported by AFOSR # FA9550-15-1-0345.

  7. Studying wedge factors and beam profiles for physical and enhanced dynamic wedges

    Directory of Open Access Journals (Sweden)

    Ahmad Misbah

    2010-01-01

    Full Text Available This study was designed to investigate variation in Varian′s Physical and Enhanced Dynamic Wedge Factors (WF as a function of depth and field size. The profiles for physical wedges (PWs and enhanced dynamic wedges (EDWs were also measured using LDA-99 array and compared for confirmation of EDW angles at different depths and field sizes. WF measurements were performed in water phantom using cylindrical 0.66 cc ionization chamber. WF was measured by taking the ratio of wedge and open field ionization data. A normalized wedge factor (NWF was introduced to circumvent large differences between wedge factors for different wedge angles. A strong linear dependence of PW Factor (PWF with depth was observed. Maximum variation of 8.9% and 4.1% was observed for 60° PW with depth at 6 and 15 MV beams respectively. The variation in EDW Factor (EDWF with depth was almost negligible and less than two per cent. The highest variation in PWF as a function of field size was 4.1% and 3.4% for thicker wedge (60° at 6 and 15 MV beams respectively and decreases with decreasing wedge angle. EDWF shows strong field size dependence and significant variation was observed for all wedges at both photon energies. Differences in profiles between PW and EDW were observed on toe and heel sides. These differences were dominant for larger fields, shallow depths, thicker wedges and low energy beam. The study indicated that ignoring depth and field size dependence of WF may result in under/over dose to the patient especially doing manual point dose calculation.

  8. Mantle wedge serpentinization effects on slab dips

    Directory of Open Access Journals (Sweden)

    Eh Tan

    2017-01-01

    Full Text Available The mechanical coupling between a subducting slab and the overlying mantle wedge is an important factor in controlling the subduction dip angle and the flow in mantel wedge. This paper investigates the role of the amount of mantle serpentinization on the subduction zone evolution. With numerical thermos-mechanical models with elasto-visco-plastic rheology, we vary the thickness and depth extent of mantle serpentinization in the mantle wedge to control the degree of coupling between the slab and mantle wedge. A thin serpentinized mantle layer is required for stable subduction. For models with stable subduction, we find that the slab dip is affected by the down-dip extent and the mantle serpentinization thickness. A critical down-dip extent exists in mantle serpentinization, determined by the thickness of the overriding lithosphere. If the down-dip extent does not exceed the critical depth, the slab is partially coupled to the overriding lithosphere and has a constant dip angle regardless of the mantle serpentinization thickness. However, if the down-dip extent exceeds the critical depth, the slab and the base of the overriding lithosphere would be separated and decoupled by a thick layer of serpentinized peridotite. This allows further slab bending and results in steeper slab dip. Increasing mantle serpentinization thickness will also result in larger slab dip. We also find that with weak mantle wedge, there is no material flowing from the asthenosphere into the serpentinized mantle wedge. All of these results indicate that serpentinization is an important ingredient when studying the subduction dynamics in the mantle wedge.

  9. Vertebral wedging characteristic changes in scoliotic spines.

    Science.gov (United States)

    Parent, Stefan; Labelle, Hubert; Skalli, Wafa; de Guise, Jacques

    2004-10-15

    A morphometric analysis of vertebral wedging in vertebrae from scoliotic specimens. To quantify the vertebral body changes in 30 anatomic specimens affected by a scoliotic deformity. Only a few studies have evaluated the exact changes occurring at the level of the vertebral body in scoliotic spines. Most are observational studies of rare scoliotic specimens presenting major curvatures. The orientation of vertebral wedging is important for the planning of corrective surgery, performing vertebral osteotomy, and the evaluation of possible growth modulation. Thirty scoliotic specimens with curves presenting various degrees of severity were studied using a three-dimensional digitizing protocol developed to create a precise three-dimensional reconstruction of the vertebrae. Every scoliotic specimen was then matched with a normal specimen, and comparisons were made on the vertebral body parameters both for thoracic and lumbar vertebrae. Analysis of variance and t test calculations were performed to identify significant differences with P = 0.05. A total of 471 vertebrae from scoliotic spines and 510 vertebrae from normal specimens were measured. Vertebral wedging increased progressively towards the apex of the curve and was maximal at the apex. Vertebral wedging was more prominent in the frontal plane, and there was minimal wedging in the sagittal plane. Vertebral heights were significantly different at T3 and T4 for the upper adjacent curve and at T6-T8 for a typical right thoracic curve, with smaller heights located on the concavity of the curve. No changes were observed on the convexity of the curve. Vertebral wedging is an essential component of the scoliotic deformity. The present study provides critical information for corrective surgery and vertebral osteotomy, as vertebral wedging occurs primarily in the frontal plane. Accurate knowledge of this deformity should also provide new insight into corrective surgical strategies aiming at growth modulation and more

  10. Optical dating of relict sand wedges and composite-wedge pseudomorphs in Flanders, Belgium

    DEFF Research Database (Denmark)

    Buylaert, Jan-Pieter; Ghysels, Günther; Murray, Andrew S.

    2009-01-01

    We report on quartz Optically Stimulated Luminescence (OSL) dating of the infill of 14 relict sand wedges and composite-wedge pseudomorphs at 5 different sites in Flanders, Belgium. A laboratory dose recovery test indicates that the single-aliquot regenerative-dose (SAR) procedure is suitable...

  11. Commissioning, clinical implementation and quality assurance of Siemen's Virtual Wedge.

    Science.gov (United States)

    Rathee, S; Kwok, C B; MacGillivray, C; Mirzaei, M

    1999-01-01

    This report presents the results of commissioning, clinical implementation and quality assurance of Siemens Virtual Wedge. Our measurements show that: (1) wedge factors are within 2% of unity, (2) percentage depth doses are within 1% of open beam data, and (3) wedged beam profiles can be modeled similarly to a physical wedge and follow a well defined equation to facilitate modeling of an arbitrary wedge angle. The gantry angle dependence of wedge profiles is similar to open beam profiles. The output of wedged fields is linear with delivered monitor units within 1%. Quality assurance results indicate the wedge profiles are very stable over time. Day to day variations of two points measured along the wedge gradient direction are within 1.5%.

  12. Graphene Plasmons in Triangular Wedges and Grooves

    DEFF Research Database (Denmark)

    Gonçalves, P. A. D.; Dias, E. J. C.; Xiao, Sanshui

    2016-01-01

    and tunability of graphene plasmons guided along the apex of a graphene-covered dielectric wedge or groove. In particular, we present a quasi-analytic model to describe the plasmonic eigenmodes in such a system, including the complete determination of their spectrum and corresponding induced potential...... and electric-field distributions. We have found that the dispersion of wedge/groove graphene plasmons follows the same functional dependence as their flat-graphene plasmon counterparts, but now scaled by a (purely) geometric factor in which all the information about the system’s geometry is contained. We...

  13. Are Pericentric Inversions Reorganizing Wedge Shell Genomes?

    Directory of Open Access Journals (Sweden)

    Daniel García-Souto

    2017-12-01

    Full Text Available Wedge shells belonging to the Donacidae family are the dominant bivalves in exposed beaches in almost all areas of the world. Typically, two or more sympatric species of wedge shells differentially occupy intertidal, sublittoral, and offshore coastal waters in any given locality. A molecular cytogenetic analysis of two sympatric and closely related wedge shell species, Donax trunculus and Donax vittatus, was performed. Results showed that the karyotypes of these two species were both strikingly different and closely alike; whilst metacentric and submetacentric chromosome pairs were the main components of the karyotype of D. trunculus, 10–11 of the 19 chromosome pairs were telocentric in D. vittatus, most likely as a result of different pericentric inversions. GC-rich heterochromatic bands were present in both species. Furthermore, they showed coincidental 45S ribosomal RNA (rRNA, 5S rRNA and H3 histone gene clusters at conserved chromosomal locations, although D. trunculus had an additional 45S rDNA cluster. Intraspecific pericentric inversions were also detected in both D. trunculus and D. vittatus. The close genetic similarity of these two species together with the high degree of conservation of the 45S rRNA, 5S rRNA and H3 histone gene clusters, and GC-rich heterochromatic bands indicate that pericentric inversions contribute to the karyotype divergence in wedge shells.

  14. Diffraction of electromagnetic waves by a rectangular wedge structure

    Science.gov (United States)

    Makarov, G. I.; Sozonov, A. P.

    A theoretical problem of electromagnetic wave diffraction in a system of two rectangular wedges is examined: a perfectly conducting wedge and a wedge with finite relative permittivity, the two wedges having a common face. For the Fourier component of the diffraction field, a shifting Riemann boundary value problem is obtained. This problem is reduced to a convolution-type integral equation for the semiaxis, with the kernel taking the form of the sum of the difference and regular kernels.

  15. Clinical effects of lateral wedge arch support insoles in knee osteoarthritis

    OpenAIRE

    Hsieh, Ru-Lan; Lee, Wen-Chung

    2016-01-01

    Abstract We compared the short-term efficacy of rigid versus soft lateral wedge arch support (LWAS) insoles for patients with knee osteoarthritis (OA), as assessed using the International Classification of Functioning, Disability and Health (ICF) system, through a prospective, double-blind, randomized controlled trial. Participants who fulfilled the combined radiographic and clinical criteria for knee OA, as defined by the American College of Rheumatology, were randomly prescribed 1 pair of r...

  16. An IBEM solution to the scattering of plane SH-waves by a lined tunnel in elastic wedge space

    Science.gov (United States)

    Liu, Zhongxian; Liu, Lei

    2015-02-01

    The indirect boundary element method (IBEM) is developed to solve the scattering of plane SH-waves by a lined tunnel in elastic wedge space. According to the theory of single-layer potential, the scattered-wave field can be constructed by applying virtual uniform loads on the surface of lined tunnel and the nearby wedge surface. The densities of virtual loads can be solved by establishing equations through the continuity conditions on the interface and zero-traction conditions on free surfaces. The total wave field is obtained by the superposition of free field and scattered-wave field in elastic wedge space. Numerical results indicate that the IBEM can solve the diffraction of elastic wave in elastic wedge space accurately and efficiently. The wave motion feature strongly depends on the wedge angle, the angle of incidence, incident frequency, the location of lined tunnel, and material parameters. The waves interference and amplification effect around the tunnel in wedge space is more significant, causing the dynamic stress concentration factor on rigid tunnel and the displacement amplitude of flexible tunnel up to 50.0 and 17.0, respectively, more than double that of the case of half-space. Hence, considerable attention should be paid to seismic resistant or anti-explosion design of the tunnel built on a slope or hillside.

  17. A beam steering technique using dielectric wedges.

    OpenAIRE

    Khan, M. R.

    1995-01-01

    The thesis describes a method of' beam steering aimed at producing a useful amount of deflection of an antenna beam from boresight, by a simple and Inexpensive method. For large antennas, It is difficult, as well as expensive, to steer the beam by more than a few beamwidths. The method studied was developed with particular reference to the beam steering requirements of Direct Broadcast Satellite flat plate antennas. The method involves two dielectric wedges, having cir...

  18. Localization of observables in the Rindler wedge

    Science.gov (United States)

    Asorey, M.; Balachandran, A. P.; Marmo, G.; de Queiroz, A. R.

    2017-11-01

    One of the striking features of QED is that charged particles create a coherent cloud of photons. The resultant coherent state vectors of photons generate a nontrivial representation of the localized algebra of observables that do not support a representation of the Lorentz group: Lorentz symmetry is spontaneously broken. We show in particular that Lorentz boost generators diverge in this representation, a result shown also by Balachandran et al. [Eur. Phys. J. C 75, 89 (2015), 10.1140/epjc/s10052-015-3305-0] (see also the work by Balachandran et al. [Mod. Phys. Lett. A 28, 1350028 (2013), 10.1142/S0217732313500284]. Localization of observables, for example in the Rindler wedge, uses Poincaré invariance in an essential way [Int. J. Geom. Methods Mod. Phys. 14, 1740008 (2017)., 10.1142/S0219887817400084]. Hence, in the presence of charged fields, the photon observables cannot be localized in the Rindler wedge. These observations may have a bearing on the black hole information loss paradox, as the physics in the exterior of the black hole has points of resemblance to that in the Rindler wedge.

  19. A comparison of exact TM plane wave diffraction by coated wedges and impedance wedges

    DEFF Research Database (Denmark)

    Andersen, Lars S.; Breinbjerg, Olav; Moore, John T.

    1996-01-01

    of the SIBC wedge is based on Maliuzhinets' solution. Comparisons have been carried out for a series of configurations including lossy coatings as well as lossless coatings permitting unattenuated propagation of surface waves. The results show that the presence of an edge in a coated structure does...... without interference from direct fields or reflected fields. Results have been obtained in the case of illumination by a transverse magnetic (TM) uniform plane wave. The analysis of the coated wedge is based on an integral equation formulation combined with a hybrid technique, while the analysis...

  20. Pilot Study: Foam Wedge Chin Support Static Tolerance Testing

    Science.gov (United States)

    2017-10-24

    AFRL-SA-WP-SR-2017-0026 Pilot Study: Foam Wedge Chin Support Static Tolerance Testing Austin M. Fischer, BS1; William W...COVERED (From – To) April – October 2017 4. TITLE AND SUBTITLE Pilot Study: Foam Wedge Chin Support Static Tolerance Testing 5a. CONTRACT NUMBER...solution to this, Defence Research and Development Canada came up with a high-level concept of attaching a foam wedge to the chest to support the helmet

  1. Experimental and numerical investigations on melamine wedges.

    Science.gov (United States)

    Schneider, S

    2008-09-01

    Melamine wedges are often used as acoustic lining material for anechoic chambers. It was proposed here to study the effects of the mounting conditions on the acoustic properties of the melamine wedges used in the large anechoic chamber at the LMA. The results of the impedance tube measurements carried out show that the mounting conditions must be taken into account when assessing the quality of an acoustic lining. As it can be difficult to simulate these mounting conditions in impedance tube experiments, a numerical method was developed, which can be used to complete the experiments or for parametric studies. By combining the finite and the boundary element method, it is possible to investigate acoustic linings with almost no restrictions as to the geometry, material behavior, or mounting conditions. The numerical method presented here was used to study the acoustic properties of the acoustic lining installed in the anechoic chamber at the LMA. Further experiments showed that the behavior of the melamine foam is anisotropic. Numerical simulations showed that this anisotropy can be used to advantage when designing an acoustic lining.

  2. Bow wave and spray dynamics by a wedge

    OpenAIRE

    Wang, Zhaoyuan; Yang, Jianming; Stern, Frederick

    2010-01-01

    Flows around a wedge-shaped bow are simulated with the aim of investigating the wave breaking mechanism and small scale features of ship bow waves. This fluid dynamics video shows the plunging wave breaking process around the wedge including the thin water sheet formation, overturning sheet with surface disturbance, fingering and breaking up into spray, plunging and splashing, and air entrainment.

  3. On size-effects in single crystal wedge indentation

    DEFF Research Database (Denmark)

    Niordson, Christian Frithiof; Kysar, Jeffrey W.

    2012-01-01

    Wedge indentation in single crystals is studied numerically, with emphasis on size-effects on the micron scale. Under the assumption of a perfectly sharp wedge indenter, a linear relationship between indentation force and indentation depth would be predicted from conventional theories lacking con...

  4. Comparison of wedge resection (Winograd procedure) and wedge resection plus complete nail plate avulsion in the treatment of ingrown toenails.

    Science.gov (United States)

    Huang, Jia-Zhang; Zhang, Yi-Jun; Ma, Xin; Wang, Xu; Zhang, Chao; Chen, Li

    2015-01-01

    The present retrospective study compared the efficacy of wedge resection (Winograd procedure) and wedge resection plus complete nail plate avulsion for the treatment of ingrown toenails (onychocryptosis). Two surgical methods were performed in 95 patients with a stage 2 or 3 ingrown toenail. Each patient was examined weekly until healing and then at 1, 6, and 12 months of follow-up. The outcomes measured were surgical duration, healing time, recurrence rate, the incidence of postoperative infection, and cosmetic appearance after surgery. Of the 95 patients (115 ingrown toenails) included in the present study, 39 (41.1%) underwent wedge resection (Winograd procedure) and 56 (59%), wedge resection plus complete nail plate avulsion. The mean surgical duration for wedge resection (Winograd procedure) and wedge resection plus complete nail plate avulsion was 14.9 ± 2.4 minutes and 15.1 ± 3.2 minutes, respectively (p = .73). The corresponding healing times were 2.8 ± 1.2 weeks and 2.7 ± 1.3 weeks (p = .70). Recurrence developed in 3 (3.2%) patients after wedge resection (Winograd procedure) and in 4 (4.2%) after wedge resection plus complete nail plate avulsion. In addition, postoperative infection occurred in 3 (3.2%) patients after wedge resection (Winograd procedure) and 2 (2.1%) after wedge resection plus complete nail plate avulsion. Both of the surgical procedures were practical and appropriate for the treatment of ingrown toenails, being simple and associated with low morbidity and a high success rate. However, cosmetically, wedge resection (Winograd procedure) would be the better choice because the nail plate remains intact. Copyright © 2015 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  5. Ground penetrating radar estimates of permafrost ice wedge depth

    Science.gov (United States)

    Parsekian, A.; Slater, L. D.; Nolan, J. T.; Grosse, G.; Walter Anthony, K. M.

    2013-12-01

    Vertical ground ice wedges associated with polygonal patterning in permafrost environments form due to frost cracking of soils under harsh winter conditions and subsequent infilling of cracks with snow melt water. Ice wedge polygon patterns have implications for lowland geomorphology, hydrology, and vulnerability of permafrost to thaw. Ice wedge dimensions may exceed two meters width at the surface and several meters depth, however few studies have addressed the question of ice wedge depth due to challenges related to measuring the vertical dimension below the ground. Vertical exposures where ice wedges maybe observed are limited to rapidly retreating lake, river, and coastal bluffs. Coring though the ice wedges to determine vertical extent is possible, however that approach is time consuming and labor intensive. Many geophysical investigations have noted signal anomalies related to the presence of ice wedges, but no reliable method for extracting wedge dimensions from geophysical data has been yet proposed. Here we present new evidence that ground penetrating radar (GPR) may be a viable method for estimating ice wedge depth. We present three new perspectives on processing GPR data collected over ice wedges that show considerable promise for use as a fast, cost effective method for evaluating ice wedge depth. Our novel approaches include 1) a simple frequency-domain analysis, 2) an S-transform frequency domain analysis and 3) an analysis of the returned signal power as a radar cross section (RCS) treating subsurface ice wedges as dihedral corner retro-reflectors. Our methods are demonstrated and validated using finite-difference time domain FDTD) GPR forward models of synthetic idealized ice wedges and field data from permafrost sites in Alaska. Our results indicate that frequency domain and signal power data provide information that is easier to extract from raw GPR data than similar information in the time domain. We also show that we can simplify the problem by

  6. Seamount subduction underneath an accretionary wedge: modelling mass wasting and wedge collapse

    Science.gov (United States)

    Mannu, Utsav; Ueda, Kosuke; Willett, Sean; Gerya, Taras; Strasser, Michael

    2017-04-01

    Seamounts (h >1 km) and knolls (h = 500 m-1000 m) cover about one-fifth of the total ocean floor area. These topographical highs of the ocean floor eventually get subducted. Subduction of these topographical features leads to severe deformation of the overriding plate and can cause extensive tectonic erosion and mass wasting of the frontal prism, which can ultimately cause a forearc wedge collapse. Large submarine landslides and the corresponding wedge collapse have previously been reported, for instance, in the northern part of the Hikurangi margin where the landslide is known as the giant Ruatoria debris avalanche, and have also been frequently reported in several seismic sections along the Costa Rica margin. Size and frequency relation of landslides suggest that the average size of submarine landslides in margins with rough subducting plates tends to be larger. However, this observation has not yet been tested or explained by physical models. In numerical subduction models, landslides take place, if at all, on a much larger timescale (in the order of 104-105 years, depending on the time steps of the model) than in natural cases. On the other hand, numerical models simulating mass wasting events such as avalanches and submarine landslides, typically model single events at a much smaller spatio-temporal domain, and do not consider long-term occurrence patterns of freely forming landslides. In this contribution, we present a multi-scale nested numerical approach to emulate short-term landslides within long-term progressive subduction. The numerical approach dynamically produces instantaneous submarine landslides and the resulting debris flow in the spatially and temporally refined inner model. Then we apply these convoluted changes in topography (e.g. due to the submarine landslide etc.) back to an outer larger-scale model instance that addresses wedge evolution. We use this approach to study the evolution of the accretionary wedge during seamount subduction.

  7. Wedge Heat-Flux Indicators for Flash Thermography

    Science.gov (United States)

    Koshti, Ajay M.

    2003-01-01

    Wedge indicators have been proposed for measuring thermal radiation that impinges on specimens illuminated by flash lamps for thermographic inspection. Heat fluxes measured by use of these indicators would be used, along with known thermal, radiative, and geometric properties of the specimens, to estimate peak flash temperatures on the specimen surfaces. These indicators would be inexpensive alternatives to high-speed infrared pyrometers, which would otherwise be needed for measuring peak flash surface temperatures. The wedge is made from any suitable homogenous material such as plastic. The choice of material is governed by the equation given. One side of the wedge is covered by a temperature sensitive compound that decomposes irreversibly when its temperature exceeds a rated temperature (T-rated). The uncoated side would be positioned alongside or in place of the specimen and exposed to the flash, then the wedge thickness at the boundary between the white and blackened portions measured.

  8. Reactive Atom Plasma Processing of Slumped Glass Wedges Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Reactive Atom Plasma (RAPTM) process will be evaluated as a rapid and practical method for fabricating precision wedges in glass sheets. The glass sheets are to...

  9. Ice-wedge volume calculation in Yedoma and thermokarst deposits

    OpenAIRE

    Ulrich, Mathias; Grosse, Guido; Strauss, Jens; Schirrmeister, Lutz

    2014-01-01

    Detailed calculations of ground-ice volumes in permafrost deposits are necessary to understand and quantify the response of permafrost landscapes to thermal disturbance and thawing. Ice wedges with their polygonal surface expression are a widespread ground-ice component of permafrost lowlands. Therefore, the wedge-ice volume (WIV) is one of the major factors to be considered, both for assessing permafrost vulnerability and for quantifying deep permafrost soil carbon inventories. Here, a strai...

  10. Scattering of wedges and cones with impedance boundary conditions

    CERN Document Server

    Lyalinov, Mikhail

    2012-01-01

    This book is a systematic and detailed exposition of different analytical techniques used in studying two of the canonical problems, the wave scattering by wedges or cones with impedance boundary conditions. It is the first reference on novel, highly efficient analytical-numerical approaches for wave diffraction by impedance wedges or cones. The applicability of the reported solution procedures and formulae to existing software packages designed for real-world high-frequency problems encountered in antenna, wave propagation, and radar cross section.

  11. The results of high tibial open wedge osteotomy in patients with varus deformity

    Directory of Open Access Journals (Sweden)

    Mahmood Jabalameli

    2013-07-01

    Full Text Available Background: High tibial open wedg osteotomy is one of the most important modality for treatment of varus deformity in order to correct deformity and improving signs and symptoms of patients with primary degenerative osteoarthritis. The aim of this study was to investigate the results of high tibial open wedge osteotomy in patients with varus deformities.Methods: This retrospective study conducted on twenty nine patients (36 knees undergone proximal tibial osteotomy operation in Shafa Yahyaian University Hospital from 2004 to 2010. Inclusion criteria were: age less than 60 years, high physical activity, varus deformity and involvement of medical compartment of knee. Patients with obesity, smoking, patelofemoral pain, lateral compartment lesion, deformity degree more than 20 degree, extension limitation and range of motion less than 90 degree were excluded. The clinical and radiologic characteristics were measured before and after operation.Results: Fourteen patients were females. All of them were younger than 50 years, with mean (±SD 27.64 (±10.88. The mean (±SD of follow up time was 4.33 (±1.7. All the patients were satisfied with the results of operation. Tenderness and pain decreased in all of them. In all patients autologus bone graft were used, in 15 cases (42.5% casting and in the rest T.Buttress plate were used for fixation of fractures. In both groups of primary and double varus the International knee documentation committee (IKDC and modified Larson indices were improved after operation, but there was no significant difference between two groups.Conclusion: High tibial open wedge osteotomy can have satisfying results in clinical signs and symptoms of patients with primary medial joint degenerative osteoarthritis. This procedure also may correct the deformity and improves the radiologic parameters of the patients.

  12. The evolving energy budget of accretionary wedges

    Science.gov (United States)

    McBeck, Jessica; Cooke, Michele; Maillot, Bertrand; Souloumiac, Pauline

    2017-04-01

    The energy budget of evolving accretionary systems reveals how deformational processes partition energy as faults slip, topography uplifts, and layer-parallel shortening produces distributed off-fault deformation. The energy budget provides a quantitative framework for evaluating the energetic contribution or consumption of diverse deformation mechanisms. We investigate energy partitioning in evolving accretionary prisms by synthesizing data from physical sand accretion experiments and numerical accretion simulations. We incorporate incremental strain fields and cumulative force measurements from two suites of experiments to design numerical simulations that represent accretionary wedges with stronger and weaker detachment faults. One suite of the physical experiments includes a basal glass bead layer and the other does not. Two physical experiments within each suite implement different boundary conditions (stable base versus moving base configuration). Synthesizing observations from the differing base configurations reduces the influence of sidewall friction because the force vector produced by sidewall friction points in opposite directions depending on whether the base is fixed or moving. With the numerical simulations, we calculate the energy budget at two stages of accretion: at the maximum force preceding the development of the first thrust pair, and at the minimum force following the development of the pair. To identify the appropriate combination of material and fault properties to apply in the simulations, we systematically vary the Young's modulus and the fault static and dynamic friction coefficients in numerical accretion simulations, and identify the set of parameters that minimizes the misfit between the normal force measured on the physical backwall and the numerically simulated force. Following this derivation of the appropriate material and fault properties, we calculate the components of the work budget in the numerical simulations and in the

  13. Beam characteristics of upper and lower physical wedge systems of Varian accelerators

    Science.gov (United States)

    Cheng, Chee-Wai; Tang, Walter L.; Das, Indra J.

    2003-11-01

    The beam characteristics of a dual physical wedge system, upper and lower, for Varian accelerators are studied over the energy range 6-18 MV. Wedge factors for both systems are measured in a water phantom as a function of field size, depth and source-to-wedge (SWD) distance. Our results indicate that apart from their physical differences, dosimetrically, the two wedge systems have percentage depth dose beyond the build-up region. The lower wedge central axis percentage depth dose is consistently lower than that of the corresponding upper wedge, with the effect more pronounced for large field sizes. The wedge profiles are identical within 2% for all field sizes, depths and energies. The wedge factors for both wedge systems are also within 2% for all field sizes and depths for both 6 and 15 MV photons and slightly higher for the 18 MV beam and 45°-60° wedge angle. The wedge factor variation with SWD reveals an interesting fact that thinner wedges (15° and 30°) result in a higher surface dose in the central axis region than thicker wedges. As the SWD increases beyond 80 cm, the reverse is true, i.e. thicker wedges produce higher surface dose than thinner wedges. It is also verified that the wedge factor at any depth and for any field size can be calculated from the wedged and open field central axis percentage depth dose, and the wedge factor at dmax, resulting in nearly 44% reduction in water phantom scanning and 80% reduction in point measurements during commissioning.

  14. Technical note: A new wedge-shaped ionization chamber component module for BEAMnrc to model the integral quality monitoring system®

    Science.gov (United States)

    Oderinde, Oluwaseyi Michael; du Plessis, FCP

    2017-12-01

    The purpose of this study was to develop a new component module (CM) namely IQM to accurately model the integral quality monitoring (IQM) system® to be used in the BEAMnrc Monte Carlo (MC) code. The IQM is essentially a double wedge ionization chamber with the central electrode plate bisecting the wedge. The IQM CM allows the user to characterize the double wedge of this ionization chamber and BEAMnrc can then accurately calculate the dose in this CM including its enclosed air regions. This has been verified against measured data. The newly created CM was added into the standard BEAMnrc CMs, and it will be made available through the NRCC website. The BEAMnrc graphical user interface (GUI) and particle ray-tracing techniques were used to validate the IQM geometry. In subsequent MC simulations, the dose scored in the IQM was verified against measured data over a range of square fields ranging from 1 × 1-30 × 30 cm2. The IQM system is designed for the present day need for a device that could verify beam output in real-time during treatment. This CM is authentic, and it can serve as a basis for researchers that have an interest in real-time beam delivery checking using wedge-shaped ionization chamber based instruments like the IQM.

  15. Tax wedge in Croatia, Belgium, Estonia, Germany and Slovakia

    Directory of Open Access Journals (Sweden)

    Ana Gabrilo

    2016-06-01

    Full Text Available The aim of this paper is to analyse the taxation of labour income in Croatia, Belgium,Estonia, Germany and Slovakia. Having presented an outline of tax system rules, the paper shows the decomposition of the net average tax wedge for different family types and different income levels based on the OECD methodology. The results show that all observed countries apply a progressive tax schedule, apart from Germany where taxation for higher gross wages is not progressive due to a  cap on the SIC base. When it comes to a taxpayer earning an average gross wage, a Croatian single worker without children has the lowest tax burden, followed by Estonia, Slovakia, Germany and Belgium. However, as regards taxpayers earning 400% of AGW, Estonia has the smallest tax wedge, followed by Slovakia, Germany, Croatia and Belgium. Similar results are obtained by analyzing the tax wedge for couples with two children where one spouse is out of work.

  16. Laparoscopic caecal wedge resection with intraoperative endoscopic assistance.

    Science.gov (United States)

    Giavarini, Luisa; Boni, Luigi; Cortellezzi, Camillo Claudio; Segato, Sergio; Cassinotti, Elisa; Rausei, Stefano; Dionigi, Gianlorenzo; Rovera, Francesca; Marzorati, Alessandro; Spampatti, Sebastiano; Sambucci, Daniele; Dionigi, Renzo

    2013-01-01

    Cancer is a potential evolution of adenomatous polyps, that is why nowadays screening programs for colorectal cancer are widely diffused. Colonoscopy is the gold standard procedure for identifying and resecting polyps; however, for some polyps resection during colonoscopy is not possible. The aim of the present study is to identify a fast and safe procedure for endoscopically resecting unresectable polyps. Patients with endoscopically unresectable polyps were scheduled for laparoscopic wedge resection under colonoscopic assistance. From November 2010 to November 2012 we treated 15 patients with endoscopically unresectable adenomatous polyps. All patients underwent a laparoscopic caecal wedge resection with intraoperative endoscopic assistance. All procedures were completed without complications and in all cases complete resection of the polyps was achieved. Laparoscopic wedge caecal resection with intraoperative colonoscopy is a fast and safe procedure that can be performed for large polyps that could not be treated endoscopically. Copyright © 2013 Elsevier Ltd and Surgical Associates Ltd. All rights reserved.

  17. Modeling and Stability Analysis of Wedge Clutch System

    Directory of Open Access Journals (Sweden)

    Jian Yao

    2014-01-01

    Full Text Available A wedge clutch with unique features of self-reinforcement and small actuation force was designed. Its self-reinforcement feature, associated with different factors such as the wedge angle and friction coefficient, brings different dynamics and unstable problem with improper parameters. To analyze this system, a complete mathematical model of the actuation system is built, which includes the DC motor, the wedge mechanism, and the actuated clutch pack. By considering several nonlinear factors, such as the slip-stick friction and the contact or not of the clutch plates, the system is piecewise linear. Through the stability analysis of the linearized system in clutch slipping phase, the stable condition of the designed parameters is obtained as α>arctan⁡(μc. The mathematical model of the actuation system is validated by prototype testing. And with the validated model, the system dynamics in both stable and unstable conditions is investigated and discussed in engineering side.

  18. Surface Geophysical Measurements for Locating and Mapping Ice-Wedges

    DEFF Research Database (Denmark)

    Ingeman-Nielsen, Thomas; Tomaskovicova, Sonia; Larsen, S.H.

    2012-01-01

    With the presently observed trend of permafrost warming and degradation, the development and availability of effective tools to locate and map ice-rich soils and massive ground ice is of increasing importance. This paper presents a geophysical study of an area with polygonal landforms in order...... to test the applicability of DC electrical resistivity tomography (ERT) and Ground Penetrating Radar (GPR) to identifying and mapping ice-wedge occurrences. The site is located in Central West Greenland, and the ice-wedges are found in a permafrozen peat soil with an active layer of about 30 cm. ERT...... and GPR measurements give a coherent interpretation of possible ice-wedge locations, and active layer probing show a tendency for larger thaw depth in the major trench systems consistent with a significant temperature (at 10 cm depth) increase in these trenches identified by thermal profiling. Three...

  19. Flow Analysis for the Falkner–Skan Wedge Flow

    DEFF Research Database (Denmark)

    Bararnia, H; Haghparast, N; Miansari, M

    2012-01-01

    In this article an analytical technique, namely the homotopy analysis method (HAM), is applied to solve the momentum and energy equations in the case of a two-dimensional incompressible flow passing over a wedge. The trail and error method and Padé approximation strategies have been used to obtain...... the constant coefficients in the approximated solution. The effects of the polynomial terms of HAM are considered and the accuracy of the results is shown, which increases with the increasing polynomial terms of HAM. Analytical results for the dimensionless velocity and temperature profiles of the wedge flow...

  20. Tool life of ceramic wedges during precise turning of tungsten

    Directory of Open Access Journals (Sweden)

    Legutko Stanislaw

    2017-01-01

    Full Text Available Properties, application and machinability of tungsten and its alloys have been demonstrated. The comparison of the tool life and wear of the wedges made of SiAlON and whisker ceramics during the precise turning at different cutting parameters have been presented. The CNC lathe DMG CTX 310 Ecoline and tungsten of 99.7 % purity were used during the experiments. Only the wedge of whisker ceramics has proved to be sufficiently suitable and only for relatively low cutting speeds.

  1. Locally fabricated metal step wedge for quality assurance in ...

    African Journals Online (AJOL)

    radiology department of the Jos University Teaching Hospital (JUTH) using locally acquired metals. The wedges were exposed to x-rays and the optical densities of the processed films measured with a densitometer. The result indicates that standard equipment can be produced from locally sourced materials, as well as to ...

  2. Point focusing with flat and wedged crossed multilayer Laue lenses.

    Science.gov (United States)

    Kubec, Adam; Melzer, Kathleen; Gluch, Jürgen; Niese, Sven; Braun, Stefan; Patommel, Jens; Burghammer, Manfred; Leson, Andreas

    2017-03-01

    Point focusing measurements using pairs of directly bonded crossed multilayer Laue lenses (MLLs) are reported. Several flat and wedged MLLs have been fabricated out of a single deposition and assembled to realise point focusing devices. The wedged lenses have been manufactured by adding a stress layer onto flat lenses. Subsequent bending of the structure changes the relative orientation of the layer interfaces towards the stress-wedged geometry. The characterization at ESRF beamline ID13 at a photon energy of 10.5 keV demonstrated a nearly diffraction-limited focusing to a clean spot of 43 nm × 44 nm without significant side lobes with two wedged crossed MLLs using an illuminated aperture of approximately 17 µm × 17 µm to eliminate aberrations originating from layer placement errors in the full 52.7 µm × 52.7 µm aperture. These MLLs have an average individual diffraction efficiency of 44.5%. Scanning transmission X-ray microscopy measurements with convenient working distances were performed to demonstrate that the lenses are suitable for user experiments. Also discussed are the diffraction and focusing properties of crossed flat lenses made from the same deposition, which have been used as a reference. Here a focal spot size of 28 nm × 33 nm was achieved and significant side lobes were noticed at an illuminated aperture of approximately 23 µm × 23 µm.

  3. Dependence of wedge transmission factor on co-60 teletherapy ...

    African Journals Online (AJOL)

    The equations were validated via linear interpolations by measuring WFs at various treatment depths using Source Axial distance (SAD) and SSD treatment techniques. The approach required only measurements of WF for a 10 x 10 cm2 field at depth of 5 cm employing SSD treatment technique per wedge filter. Using the ...

  4. Fixed Points of Maps of a Nonaspherical Wedge

    Directory of Open Access Journals (Sweden)

    Merrill Keith

    2009-01-01

    Full Text Available Abstract Let be a finite polyhedron that has the homotopy type of the wedge of the projective plane and the circle. With the aid of techniques from combinatorial group theory, we obtain formulas for the Nielsen numbers of the selfmaps of .

  5. The effect of shoe design and lateral wedging on knee loading

    DEFF Research Database (Denmark)

    Mølgaard, Carsten; Kersting, Uwe G.

    wedges were observed in all three types of shoes. However, differences between shoe design were of similar magnitude as the effect of laterally wedged insoles. Only marginal changes in muscle activity for lateral hamstrings during barefoot toe-out walking and gastrocnemius when using the Oxford wedged...

  6. A new sand-wedge-forming mechanism in an extra-arid area

    Science.gov (United States)

    Li, Hongshou; Wang, Wanfu; Wu, Fasi; Zhan, Hongtao; Zhang, Guobing; Qiu, Fei

    2014-04-01

    A survey found that sand wedges are widely distributed in the extremely extra-arid Gobi region of Dunhuang, China. The sand wedges are still developing. Well-developed sand wedges are surrounded by polygonal areas showing fractal structures. The depth of a well-developed sand wedge is 50-60 cm and its maximum width is 50-60 cm, so the depth/width ratio is 1.0. The interface between the wedge and matrix is arc-shaped. The mechanical composition of the sand wedges compared to the matrix is such that 76.72% of the particles have diameters ≤ 0.25 mm and show vertical sand laminations in the sand wedge, while 55.19% of the particles in the matrix are ≥ 2.00 mm in diameter. The particle diameters are consistent with the width of the sand-wedge fractures. The salt content in the sand wedges is 3.13 g/kg, while that of the matrix is 40.86 g/kg. The large salinity difference shows that the sand in the wedges comes from drift sand or cladding layers where salinity is lower, and that the sand wedge was formed in an arid climate. Displacement and pressure are closely associated with the daily temperature variation; they fluctuate significantly following the temperature. Measurements reveal the movement of thermal-contraction fissures. Pressure monitoring identified that wet expansions occurred after rainfall, which made the sand wedges become tightly joined to the matrix. Following this, as the soil became desiccated and shrank, a crack opened in the middle of the sand wedge. This was then filled with drift sand. With the next rainfall, the system moved into another development cycle. The current article reveals a new mechanism for forming sand wedges in extra-arid conditions. Arid sand wedges are a unique drought-induced surface landmark resulting from long-term, natural, dry-climate processes.

  7. Experimental investigation of sound absorption of acoustic wedges for anechoic chambers

    Science.gov (United States)

    Belyaev, I. V.; Golubev, A. Yu.; Zverev, A. Ya.; Makashov, S. Yu.; Palchikovskiy, V. V.; Sobolev, A. F.; Chernykh, V. V.

    2015-09-01

    The results of measuring the sound absorption by acoustic wedges, which were performed in AC-3 and AC-11 reverberation chambers at the Central Aerohydrodynamic Institute (TsAGI), are presented. Wedges of different densities manufactured from superfine basaltic and thin mineral fibers were investigated. The results of tests of these wedges were compared to the sound absorption of wedges of the operating AC-2 anechoic facility at TsAGI. It is shown that basaltic-fiber wedges have better sound-absorption characteristics than the investigated analogs and can be recommended for facing anechoic facilities under construction.

  8. The effect of wedge position and inlet geometry on shock wave reflection

    Science.gov (United States)

    Hall, R. E.; da Silva, N. P.; Skews, B. W.; Paton, R. T.

    2017-02-01

    Experiments were conducted in a shock tube to determine the effect of planar wedge inlet geometry on the shock wave reflection pattern that occurred on a wedge. High-speed schlieren imaging was used to visualize the experiments conducted in air with a nominal incident shock strength of Mach 1.31. The experimental test pieces consisted of a wedge mounted above the floor of the shock tube where the underside wedge angle was varied. The upper wedge angle was fixed at 30°, resulting in a Mach reflection. The underside wedge angle was either 30° or 90°, corresponding to a conventional and blunt wedge respectively. For the cases presented here, the reflected shock from the initial interaction reflects off of the shock tube floor and diffracts around the wedge apex. A density gradient is formed at the wedge apex due to this process and results in a vortex being shed for the 90° wedge. It was shown by simple measurements that the diffracted wave could reach the triple point of the upper Mach reflection if the wedge were of sufficient length.

  9. Thoracoscopic pulmonary wedge resection without post-operative chest drain

    DEFF Research Database (Denmark)

    Holbek, Bo Laksafoss; Hansen, Henrik Jessen; Kehlet, Henrik

    2016-01-01

    effusion and coagulopathy. Chest X-rays were done twice on the day of surgery. 30-day complications were compiled from patient records. RESULTS: 49 patients underwent 51 unilateral VATS wedge resections without using a post-operative chest drain. No patient required reinsertion of a chest drain. 30 (59...... %) patients had a pneumothorax of mean size 12 ± 12 mm on supine 8-h post-operative X-ray for which the majority resolved spontaneously within 2-week control. There were no complications on 30-day follow-up. Median length of stay was 1 day. CONCLUSIONS: The results support that VATS wedge resection...... for pulmonary nodules without a post-operative chest drain may be safe in a selected group of patients....

  10. Wedge Diffraction as an Instance of Radiative Shielding

    CERN Document Server

    Grzesik, J A

    2016-01-01

    The celebrated Sommerfeld wedge diffraction solution is reexamined from a null interior field perspective. Exact surface currents provided by that solution, when considered as disembodied half-plane laminae radiating into an ambient, uniform space both inside and outside the wedge proper, do succeed in reconstituting both a specular, mirror field above the exposed face, and a shielding plane-wave field of a sign opposite to that of the incoming excitation which, under superposition, creates both the classical, geometric-optics shadow, and a strictly null interior field at the dominant, plane-wave level. Both mirror and shadow radiated fields are controlled by the residue at just one simple pole encountered during a spectral radiative field assembly, fixed in place by incidence direction $\\phi_{0}$ as measured from the exposed face. The radiated fields further provide diffractive contributions drawn from two saddle points that track observation angle $\\phi.$ Even these, more or less asymptotic contributions, a...

  11. Direct FVM Simulation for Sound Propagation in an Ideal Wedge

    Directory of Open Access Journals (Sweden)

    Hongyu Ji

    2016-01-01

    Full Text Available The sound propagation in a wedge-shaped waveguide with perfectly reflecting boundaries is one of the few range-dependent problems with an analytical solution. This provides a benchmark for the theoretical and computational studies on the simulation of ocean acoustic applications. We present a direct finite volume method (FVM simulation for the ideal wedge problem, and both time and frequency domain results are analyzed. We also study the broadband problem with large-scale parallel simulations. The results presented in this paper validate the accuracy of the numerical techniques and show that the direct FVM simulation could be applied to large-scale complex acoustic applications with a high performance computing platform.

  12. Analysis of Adhesively Bonded Ceramics Using an Asymmetric Wedge Test

    Science.gov (United States)

    2008-12-01

    edges along the lengths of the titanium adherends was cleaned with a small hand-held electric grinding wheel to remove excess adhesive flow. The...energy and bond line durability of titanium bonded to alumina using a structural epoxy film adhesive. This testing scheme limited bending to the more... epoxy adhesive used for the study is estimated to have an initial Gc value ranging from 1000 to 2000 J/m2. A wedge 4 thickness () of 3.18 mm

  13. Wedge Prism for Direction Resolved Speckle Correlation Interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Pechersky, M.J.

    1999-01-20

    The role of a wedge prism for strain sign determination and enhancing the sensitivity for sub-fringe changes is emphasized. The design and incorporation aspects for in-plane sensitive interferometers have been described in detail. Some experimental results dealing with stress determination by laser annealing and speckle corelation interferometry are presented. The prism can also be applied to produce standardized carrier fringes in spatial phase shifting interferometry.

  14. Large scale test of wedge shaped micro strip gas counters

    Energy Technology Data Exchange (ETDEWEB)

    Ackermann, M.; Atz, S.; Aulchenko, V.; Bachmann, S.; Baiboussinov, B.; Barthe, S.; Beaumont, W.; Beckers, T.; Beissel, F.; Benhammou, Y.; Bergdolt, A.M.; Bernier, K.; Bluem, P.; Bondar, A.; Bouhali, O.; Boulogne, I.; Bozzo, M.; Brom, J.M.; Camps, C.; Chorowicz, V.; Coffin, J.; Commichau, V.; Contardo, D.; Croix, J.; Troy, J. de; Drouhin, F.; Eberle, H.; Fluegge, G.; Fontaine, J.-C.; Geist, W.; Goerlach, U.; Gundlfinger, K.; Hangarter, K.; Haroutunian, R.; Helleboid, J.M.; Henkes, Th.; Hoffer, M.; Hoffman, C.; Huss, D.; Ischebeck, R.; Jeanneau, F.; Juillot, P.; Junghans, S.; Kapp, M.R.; Kaercher, K.; Knoblauch, D.; Kraeber, M.; Krauth, M.; Kremp, J.; Lounis, A.; Luebelsmeyer, K.; Maazouzi, C.; Macke, D.; Metri, R.; Mirabito, L.; Mueller, Th.; Nagaslaev, V.; Neuberger, D.; Nowack, A.; Pallares, A.; Pandoulas, D.; Petertill, M.; Pooth, O.; Racca, C.; Ripp, I.; Ruoff, E.; Sauer, A.; Schmitz, P.; Schulte, R.; Schultz von Dratzig, A.; Schunk, J.P.; Schuster, G.; Schwaller, B.; Shektman, L.; Siedling, R.; Sigward, M.H.; Simonis, H.J.; Smadja, G.; Stefanescu, J.; Szczesny, H.; Tatarinov, A.; Thuemmel, W.H.; Tissot, S.; Titov, V.; Todorov, T.; Tonutti, M.; Udo, F.; Velde, C. Vander. E-mail: vandervelde@hep.iihe.ac.be; Doninck, W. van; Dyck, Ch. van; Vanlaer, P.; Lancker, L. van; Verdini, P.G.; Weseler, S.; Wittmer, B.; Wortmann, R.; Zghiche, A.; Zhukov, V

    1999-11-01

    In order to check the system aspects of the forward-backward MSGC tracker designed for the future CMS experiment at LHC, 38 trapezoidal MSGC counters assembled in six multi-substrates detector modules were built and exposed to a muon beam at the CERN SPS. Results on the gain uniformity along the wedge-shaped strip pattern and across the detector modules are shown together with measurements of the detection efficiency and the spatial resolution.

  15. Wedges, Wages, and Productivity under the Affordable Care Act

    OpenAIRE

    Casey B. Mulligan; Trevor S. Gallen

    2013-01-01

    Our paper documents the large labor market wedges created by taxes, subsidies, and regulations included in the Affordable Care Act. The law changes terms of trade in both goods and factor markets for firms offering health insurance coverage. We use a multi-sector (intra-national) trade model to predict and quantify consequences of the Affordable Care Act for the patterns of output, labor usage, and employee compensation. We find that the law will significantly redistribute from high-wage work...

  16. Large scale test of wedge shaped micro strip gas counters

    CERN Document Server

    Ackermann, M; Aulchenko, V M; Bachmann, S; Baibusinov, B O; Barthe, S; Beaumont, W; Beckers, T; Beissel, F; Benhammou, Ya; Bergdolt, A M; Bernier, K; Blüm, H P; Bondar, A E; Bouhali, O; Boulogne, I; Bozzo, M; Brom, J M; Camps, C; Chorowicz, V; Coffin, J P; Commichau, V; Contardo, D; Croix, J; De Troy, J G; Drouhin, F; Eberle, H; Flügge, G; Fontaine, J C; Geist, Walter M; Goerlach, U; Gundlfinger, K; Hangarter, K; Haroutunian, R; Helleboid, J M; Henkes, T; Hoffer, M; Hoffmann, C; Huss, D; Ischebeck, R; Jeanneau, F; Juillot, P; Junghans, S; Kapp, M R; Kärcher, K; Knoblauch, D; Kräber, M H; Krauth, M; Kremp, J; Lounis, A; Lübelsmeyer, K; Maazouzi, C; Macke, D; Metri, R; Mirabito, L; Müller, T; Nagaslaev, V; Neuberger, D; Nowak, A; Pallarès, A; Pandoulas, D; Petertill, M; Pooth, O; Racca, C; Ripp, I; Ruoff, E; Sauer, A; Schmitz, P; Schulte, R; Schultz von Dratzig, A; Schunk, J P; Schuster, G; Schwaller, B; Shekhtman, L I; Siedling, R; Sigward, M H; Simonis, H J; Smadja, G; Stefanescu, J; Szczesny, H; Tatarinov, A A; Thümmel, W H; Tissot, S; Titov, V; Todorov, T; Tonutti, M; Udo, Fred; Van der Velde, C; Van Doninck, W K; Van Dyck, C; Vanlaer, P; Van Lancker, L; Verdini, P G; Weseler, S; Wittmer, B; Wortmann, R; Zghiche, A; Zhukov, V

    1999-01-01

    In order to check the system aspects of the forward-backward MSGC tracker designed for the future CMS experiment at LHC, 38 trapezoidal MSGC counters assembled in six multi-substrates detector modules were built and exposed to a muon beam at the CERN SPS. Results on the gain uniformity along the wedge-shaped strip pattern and across the detector modules are shown together with measurements of the detection efficiency and the spatial resolution. (8 refs).

  17. On the acoustic wedge design and simulation of anechoic chamber

    Science.gov (United States)

    Jiang, Changyong; Zhang, Shangyu; Huang, Lixi

    2016-10-01

    This study proposes an alternative to the classic wedge design for anechoic chambers, which is the uniform-then-gradient, flat-wall (UGFW) structure. The working mechanisms of the proposed structure and the traditional wedge are analyzed. It is found that their absorption patterns are different. The parameters of both structures are optimized for achieving minimum absorber depth, under the condition of absorbing 99% of normal incident sound energy. It is found that, the UGFW structure achieves a smaller total depth for the cut-off frequencies ranging from 100 Hz to 250 Hz. This paper also proposes a modification for the complex source image (CSI) model for the empirical simulation of anechoic chambers, originally proposed by Bonfiglio et al. [J. Acoust. Soc. Am. 134 (1), 285-291 (2013)]. The modified CSI model considers the non-locally reactive effect of absorbers at oblique incidence, and the improvement is verified by a full, finite-element simulation of a small chamber. With the modified CSI model, the performance of both decorations with the optimized parameters in a large chamber is simulated. The simulation results are analyzed and checked against the tolerance of 1.5 dB deviation from the inverse square law, stipulated in the ISO standard 3745(2003). In terms of the total decoration depth and anechoic chamber performance, the UGFW structure is better than the classic wedge design.

  18. The analysis of terminal endpoint events in stepped wedge designs.

    Science.gov (United States)

    Zhan, Zhuozhao; de Bock, Geertruida H; Wiggers, Theo; van den Heuvel, Edwin

    2016-10-30

    The stepped wedge design is a unique clinical trial design that allows for a sequential introduction of an intervention. However, the statistical analysis is unclear when this design is applied in survival data. The time-dependent introduction of the intervention in combination with terminal endpoints and interval censoring makes the analysis more complicated. In this paper, a time-on-study scale discrete survival model was constructed. Simulations were conducted primarily to study the performance of our model for different settings of the stepped wedge design. Secondary, we compared our approach to continuous Cox proportional hazard model. The results show that the discrete survival model estimates the intervention effects unbiasedly. If the length of the censoring interval is increased, the precision of the estimates is decreased. Without left truncation and late entry, the number of steps improves the precision of the estimates, whereas in combination of left truncation and late entry, the number of steps decreases the precision. Given the same number of participants and clusters, a parallel group design has higher precision than a stepped wedge design. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  19. Chronology and palaeoenvironmental implications of the ice-wedge pseudomorphs and composite-wedge casts on the Magdalen Islands (eastern Canada)

    DEFF Research Database (Denmark)

    Remillard, A.M.; Hetu, B.; Bernatchez, P.

    2015-01-01

    The Magdalen Islands are a valuable terrestrial record, evidencing the complex glacial and periglacial history of the Gulf of St. Lawrence. Thirteen structures interpreted as ice-wedge pseudomorphs or composite-wedge casts were observed at four sites on the southern Magdalen Islands and testify t...

  20. The accuracy of dynamic wedge dose computation in the ADAC Pinnacle RTP system.

    Science.gov (United States)

    Shao, H; Wu, X; Luo, C; Crooks, A; Bernstein, A; Markoe, A

    2004-01-01

    The nonphysical wedge is a modality that uses computer-controlled jaw motion to generate wedge-shaped dose distributions. There are Varian enhanced dynamic wedges (EDWs) and Siemens virtual wedges (VWs). We recently commissioned dynamic wedges on both Varian and Siemens LINACs. The beam data, acquired with a Wellhofer chamber array and a Sun Nuclear profiler, are used for modeling in the ADAC Pinnacle system. As recommended by ADAC, only a limited number of beam data is measured and used for beam modeling. Therefore, the dose distributions of dynamic wedges generated by Pinnacle must be examined. Following the commissioning of the dynamic wedges, we used Pinnacle to generate a number of dose distributions with different energies, wedge angles, field sizes, and depths. The computed data from Pinnacle are then compared with the measured data. The deviations of the output factor in all square and rectangular fields are mostly within 2.0% for both EDW and VW. For asymmetric fields, the deviations are within 3%. However, exceptions of differences more than 3% have been found in a larger field and large wedge combinations. The precision of the beam profiles generated by Pinnacle is also evaluated. As a result of this investigation, we present a scope of quality assurance tests that are necessary to ensure acceptable consistency between the delivered dose and the associated treatment plan when dynamic wedges are applied.

  1. Study of stress distribution of forming slandering of automobile semi-axes with multi-wedge cross wedge rolling by FEM simulation

    Science.gov (United States)

    Zhao, Jing; Shu, Xuedao; Hu, Zhenghuan

    2005-12-01

    Cross wedge rolling with multi-wedge (MCWR) is a new advanced technology of forming the slandering of automobile semi-axes. However, restriction relationship between main wedges and side wedges is complex, there is not almost theory forming automobile axes at inland or overseas. According to the characteristics of forming slandering of automobile semi-axes by MCWR, three-dimensional parameterized model of the MCWR and corresponding program of finite element simulation is worked out. Adopting FEM analysis technology, rules of stress distribution in work piece at main stages, such as knifing zone, stretching zone in main wedges was investigated. The results indicate that forming automobile semi-axes by MCWR is feasible. It provides reliable theory foundation for designing mould of rolling automobile axes by MCWR and choosing technology parameters.

  2. Dose Distribution According to the Tissue Composition Using Wedge Filter by Radiochromic Film

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yon Lae [Dept. of Radiologic Technology, Choonhae College of Health Sciences, Ulsan (Korea, Republic of); Lee, Jeong Woo; Park, Byung Moon [Dept. of Radiation Oncology, Konku University Hospital, Seoul (Korea, Republic of); Jung, Jae Yong; Park, Ji Yeon; Suh, Tae Suk [Dept. of Biomedical Engineering, Catholic University, Seoul (Korea, Republic of)

    2012-06-15

    The purpose of this study is to analyze the dose distribution when wedge filter is used in the various tissue electron density materials. The dose distribution was assessed that the enhanced dynamic wedge filter and physical wedge filter were used in the solid water phantom, cork phantom, and air cavity. The film dosimetry was suitable simple to measure 2D dose distribution. Therefore, the radiochromic films (Gafchromic EBT2, ISP, NJ, USA) were selected to measure and to analyze the dose distributions. A linear accelerator using 6 MV photon were irradiated to field size of 10 x10 cm{sup 2} with 400 MUs. The dose distributions of EBT2 films were analyzed the in-field area and penumbra regions by using dose analysis program. In the dose distributions of wedge field, the dose from a physical wedge was higher than that from a dynamic wedge at the same electron density materials. A dose distributions of wedge type in the solid water phantom and the cork phantom were in agreements with 2%. However, the dose distribution in air cavity showed the large difference with those in the solid water phantom or cork phantom dose distributions. Dose distribution of wedge field in air cavity was not shown the wedge effect. The penumbra width, out of the field of thick and thin, was observed larger from 1 cm to 2 cm at the thick end. The penumbra of physical wedge filter was much larger average 6% than the dynamic wedge filter. If the physical wedge filter is used, the dose was increased to effect the scatter that interacted with photon and physical wedge. In the case of difference in electron like the soft tissue, lung, and air, the transmission, absorption, and scattering were changed in the medium at high energy photon. Therefore, the treatment at the difference electron density should be inhomogeneity correction in treatment planning system.

  3. A regional-scale estimation of ice wedge ice volumes in the Canadian High Arctic

    Science.gov (United States)

    Templeton, M.; Pollard, W. H.; Grand'Maison, C. B.

    2016-12-01

    Ice wedges are both prominent and environmentally vulnerable features in continuous permafrost environments. As the world's Arctic regions begin to warm, concern over the potential effects of ice wedge melt out has become an immediate issue, receiving much attention in the permafrost literature. In this study we estimate the volume of ice wedge ice for large areas in the Canadian High Arctic through the use of high resolution satellite imagery and the improved capabilities of Geographic Information Systems (GIS). The methodology used for this study is similar to that of one performed in Siberia and Alaska by Ulrich et al, in 2014. Utilizing Ulrich's technique, this study detected ice wedge polygons from satellite imagery using ArcGIS. The average width and depth of these ice wedges were obtained from a combination of field data and long-term field studies for the same location. The assumptions used in the analysis of ice wedge volume have been tested, including trough width being representative of ice wedge width, and ice wedge ice content (Pollard and French 1980). This study used specific field sites located near Eureka on Ellesmere Island (N80°01', W85°43') and at Expedition Fiord on Axel Heiberg Island (N79°23', W90°59'). The preliminary results indicate that the methodology used by Ulrich et al, 2014 is transferrable to the Canadian High Arctic, and that ice wedge volumes range between 3-10% of the upper part of permafrost. These findings are similar to previous studies and their importance is made all the more evident by the dynamic nature of ice wedges where it could be argued that they are a key driver of thermokarst terrain. The ubiquitous nature of ice wedges across arctic terrain highlights the importance and the need to improve our understanding of ice wedge dynamics, as subsidence from ice wedge melt-out could lead to large scale landscape change.

  4. Degradation and stabilization of ice wedges: Implications for assessing risk of thermokarst in northern Alaska

    Science.gov (United States)

    Kanevskiy, Mikhail; Shur, Yuri; Jorgenson, Torre; Brown, Dana R. N.; Moskalenko, Nataliya; Brown, Jerry; Walker, Donald A.; Raynolds, Martha K.; Buchhorn, Marcel

    2017-11-01

    Widespread degradation of ice wedges has been observed during the last decades in numerous areas within the continuous permafrost zone of Eurasia and North America. To study ice-wedge degradation, we performed field investigations at Prudhoe Bay and Barrow in northern Alaska during 2011-2016. In each study area, a 250-m transect was established with plots representing different stages of ice-wedge degradation/stabilization. Field work included surveying ground- and water-surface elevations, thaw-depth measurements, permafrost coring, vegetation sampling, and ground-based LiDAR scanning. We described cryostratigraphy of frozen soils and stable isotope composition, analyzed environmental characteristics associated with ice-wedge degradation and stabilization, evaluated the vulnerability and resilience of ice wedges to climate change and disturbances, and developed new conceptual models of ice-wedge dynamics that identify the main factors affecting ice-wedge degradation and stabilization and the main stages of this quasi-cyclic process. We found significant differences in the patterns of ice-wedge degradation and stabilization between the two areas, and the patterns were more complex than those previously described because of the interactions of changing topography, water redistribution, and vegetation/soil responses that can interrupt or reinforce degradation. Degradation of ice wedges is usually triggered by an increase in the active-layer thickness during exceptionally warm and wet summers or as a result of flooding or disturbance. Vulnerability of ice wedges to thermokarst is controlled by the thickness of the intermediate layer of the upper permafrost, which overlies ice wedges and protects them from thawing. In the continuous permafrost zone, degradation of ice wedges rarely leads to their complete melting; and in most cases wedges eventually stabilize and can then resume growing, indicating a somewhat cyclic and reversible process. Stabilization of ice wedges

  5. Dosimetric Characteristics of 6 MV Modified Beams by Physical Wedges of a Siemens Linear Accelerator.

    Science.gov (United States)

    Zabihzadeh, Mansour; Birgani, Mohammad Javad Tahmasebi; Hoseini-Ghahfarokhi, Mojtaba; Arvandi, Sholeh; Hoseini, Seyed Mohammad; Fadaei, Mahbube

    2016-01-01

    Physical wedges still can be used as missing tissue compensators or filters to alter the shape of isodose curves in a target volume to reach an optimal radiotherapy plan without creating a hotspot. The aim of this study was to investigate the dosimetric properties of physical wedges filters such as off-axis photon fluence, photon spectrum, output factor and half value layer. The photon beam quality of a 6 MV Primus Siemens modified by 150 and 450 physical wedges was studied with BEAMnrc Monte Carlo (MC) code. The calculated present depth dose and dose profile curves for open and wedged photon beam were in good agreement with the measurements. Increase of wedge angle increased the beam hardening and this effect was more pronounced at the heal region. Using such an accurate MC model to determine of wedge factors and implementation of it as a calculation algorithm in the future treatment planning systems is recommended.

  6. Ice-wedge based permafrost chronologies and stable-water isotope records from Arctic Siberia

    OpenAIRE

    Wetterich, Sebastian; Opel, Thomas; Meyer, Hanno; Schwamborn, Georg; Schirrmeister, Lutz; Derevyagin, Alexander Yu

    2016-01-01

    Late Quaternary permafrost of northern latitudes contains large proportions of ground ice, including pore ice, segregation ice, massive ice, buried glacier ice and in particular ice wedges. Fossil ice-wedges are remnants of polygonal patterned ground in former tundra areas, which evolved over several tens of thousands of years in non-glaciated Beringia. Ice wedges originate from repeated frost cracking of the ground in winter and subsequent crack filling by snowmelt and re-freezing in the gro...

  7. Pan-Arctic ice-wedge degradation in warming permafrost and its influence on tundra hydrology

    OpenAIRE

    Liljedahl, Anna K.; Boike, Julia; Daanen, Ronald P.; Fedorov, Alexander N.; Frost, Gerald V.; Grosse, Guido; Hinzman, Larry D.; Iijma, Yoshihiro; Jorgenson, Janet C.; Matveyeva, Nadya; Necsoiu, Marius; Raynolds, Martha K.; Romanovsky, Vladimir E.; Schulla, Jörg; Tape, Ken D.

    2016-01-01

    Ice wedges are common features of the subsurface in permafrost regions. They develop by repeated frost cracking and ice vein growth over hundreds to thousands of years. Ice-wedge formation causes the archetypal polygonal patterns seen in tundra across the Arctic landscape. Here we use field and remote sensing observations to document polygon succession due to ice-wedge degradation and trough development in ten Arctic localities over sub-decadal timescales. Initial thaw drains polygon centres ...

  8. Wedge factor constituents of high-energy photon beams: head and phantom scatter dose components.

    Science.gov (United States)

    Heukelom, S; Lanson, J H; Mijnheer, B J

    1994-07-01

    The head and phantom scatter contribution to the output of a treatment machine have been determined for open and wedged 60Co gamma-ray beams and 4, 8, 16 and 25 MV X-ray beams, using an extended and a small-sized phantom. The wedge factor variation with field size and phantom depth have been analysed as a function of both scatter components. For the wedged beams a stronger increase of the head scatter contribution with field size, i.e. 4-9% for field sizes increasing from 5 cm x 5 cm to 20 cm x 20 cm, has been observed compared with open beams. This result indicates that the wedge factor variation with field size is related to a change of the primary photon fluence. Our study shows that the ratio of the head and phantom scatter contribution for the wedged and open beams remains unchanged for all beams except the 4 and 25 MV X-ray beam. This implies that, except for these latter energies, the variation of the wedge factor with phantom depth is determined by the wedge-induced change of the primary photon energy fluence. For the 4 and 25 MV X-ray beam it is shown that the wedge factor is also influenced by a change of the phantom scatter contribution. The wedge factor for the 25 MV X-ray beam is strongly influenced by the electron contamination for phantom depths up to 6 cm. For the 60Co and the 4 MV photon beam it is shown that the wedge factor decreases slightly with increasing source-to-skin distance due to a reduced contribution to the total dose from photons scattered in the wedge. For clinical use, an algorithm is given to calculate the wedge factor variation with field size and phantom depth.

  9. Development and growth of structural wedges in northwest Qaidam basin, China

    Science.gov (United States)

    Sun, Y.; Shaw, J. H.; Guan, S.; Ma, D.

    2016-12-01

    Structural wedges contain two connected fault segments, a fore-thrust and back-thrust, that bound a triangular or wedge shaped fault block. We document a series of natural structural wedges in northwest Qaidam basin, China, where syntectonic strata record deformation timing and kinematics. The Qaidam basin is located at the northern margin of the Tibetan Plateau and developed more than one hundred anticlinal structures, many of which exhibit characteristics of structural wedges. Based on fault related fold theory, we interpret and model these structures using subsurface seismic reflection data, surface geological exposures, remote sensing and digital elevation data. The structures in northwest Qaidam basin typically include a southwest dipping thrust fault, constituting the back-thrust of the wedge system. Fault-bend and propagation folds develop in the hanging walls of these faults. At depth, these back-thrusts are rooted into northeast dipping fore-thrusts forming structural wedges. These wedge structures are distinguished by having elevated strata in the footwalls of the back-thrusts, and synclinal folds that extend upward from the wedge tips. Deformation timing and kinematics of the structural wedges are constrained by syntectonic (growth) strata. With these constraints, we forward model several of these structures (Dafengshan, Changweiliang, Heiliangzi, Jiandingshan, and Jianbei ) using MOVE software. These forward models help to characterize the location and geometry of the deeper faults, many of which are tectonically active. The forward modelling process indicates that some of the wedges include imbricated back-thrusts. Moreover, all of the systems exhibit significant variations along strike. We apply palinspastic and map-based restoration methods to establish that several of these wedge structures are part of a linked system, where along-strike changes in geometry reflect slip transfer from one wedge system to another.

  10. Understanding Flow and Transport in Ice Wedge Polygons Using Tracers

    Science.gov (United States)

    Wales, N. A.; Newman, B. D.; Wilson, C. J.; Gomez-Velez, J. D.

    2016-12-01

    Ice wedge polygons are among the most prevalent landforms in lowland Arctic landscapes and are associated with high concentrations of permafrost carbon. The fate of this carbon in a warming climate is dependent on the rate of ice wedge degradation and its influence on hydrology. Most regional and pan-arctic land models focus on the representation of vertical water fluxes in the form of infiltration and evapotranspiration. Our work aims to better quantify the relative roles of vertical and subsurface horizontal water fluxes in these landscapes, providing data to revise, test, and calibrate permafrost hydrology representations in these models. We examined the controls of frost table depth, microtopography, and soil type on subsurface flow and transport within both a low centered polygon (LCP) and a high centered polygon (HCP) to better understand how topographic inversion due to ice wedge degradation will impact subsurface horizontal flow. A bromide solution was applied at both polygons in July of 2015. Macrorhizon samplers placed at various depths in the polygon centers, rims, and troughs were used to monitor tracer concentrations. Water level data and frost table depth measurements were also taken throughout the experiment. Tracer movement has been relatively slow, taking most of the first field season to arrive at a subsurface sampler, also called "breakthrough". Tracer travel times from polygon centers to rims and from surface to the frost table were shorter in the LCP than in the HCP. Preferential flow paths, influenced by topography and frost table depth, were found exist between polygon centers and troughs. Preliminary data also suggests that water typically flows downward to the frost table and then laterally. Correlations between tracer arrival time and absolute thaw depth are assessed, along with the relationships between tracer breakthough curves and polygon types and features.

  11. Modes of continental extension in a crustal wedge

    KAUST Repository

    Wu, Guangliang

    2015-07-01

    © 2015 Elsevier B.V. We ran numerical experiments of the extension of a crustal wedge as an approximation to extension in an orogenic belt or a continental margin. We study the effects of the strength of the lower crust and of a weak mid-crustal shear zone on the resulting extension styles. A weak mid-crustal shear zone effectively decouples upper crustal extension from lower crustal flow. Without the mid-crustal shear zone, the degree of coupling between the upper and the lower crust increases and extension of the whole crust tends to focus on the thickest part of the wedge. We identify three distinct modes of extension determined by the strength of the lower crust, which are characterized by 1) localized, asymmetric crustal exhumation in a single massif when the lower crust is weak, 2) the formation of rolling-hinge normal faults and the exhumation of lower crust in multiple core complexes with an intermediate strength lower crust, and 3) distributed domino faulting over the weak mid-crustal shear zone when the lower crust is strong. A frictionally stronger mid-crustal shear zone does not change the overall model behaviors but extension occurred over multiple rolling-hinges. The 3 modes of extension share characteristics similar to geological models proposed to explain the formation of metamorphic core complexes: 1) the crustal flow model for the weak lower crust, 2) the rolling-hinge and crustal flow models when the lower crust is intermediate and 3) the flexural uplift model when the lower crust is strong. Finally we show that the intensity of decoupling between the far field extension and lower crustal flow driven by the regional pressure gradient in the wedge control the overall style of extension in the models.

  12. Thermodynamic and kinetic supercooling of liquid in a wedge pore.

    Science.gov (United States)

    Nowak, Dominika; Heuberger, Manfred; Zäch, Michael; Christenson, Hugo K

    2008-10-21

    Cyclohexane allowed to capillary condense from vapor in an annular wedge pore of mica in a surface force apparatus (SFA) remains liquid down to at least 14 K below the bulk melting-point T(m). This is an example of supercooling of a liquid due to confinement, like melting-point depression in porous media. In the wedge pore, however, the supercooled liquid is in equilibrium with vapor, and the amount of liquid (and thereby the radius of curvature r of the liquid-vapor interface) depends on the surface tension gamma(LV) of the liquid, not the interfacial tension between the solid and liquid. At coexistence r is inversely proportional to the temperature depression DeltaT below T(m), in accordance with a recently proposed model [P. Barber, T. Asakawa, and H. K. Christenson, J. Phys. Chem. C 111, 2141 (2007)]. We have now extended this model to include effects due to the temperature dependence of both the surface tension and the enthalpy of melting. The predictions of the improved model have been quantitatively verified in experiments using both a Mark IV SFA and an extended surface force apparatus (eSFA). The three-layer interferometer formed by the two opposing, backsilvered mica surfaces in a SFA was analyzed by conventional means (Mark IV) and by fast spectral correlation of up to 40 fringes (eSFA). We discuss the absence of freezing in the outermost region of the wedge pore down to 14 K below T(m) and attribute it to nonequilibrium (kinetic) supercooling, whereas the inner region of the condensate is thermodynamically supercooled.

  13. Thermodynamic and kinetic supercooling of liquid in a wedge pore

    Science.gov (United States)

    Nowak, Dominika; Heuberger, Manfred; Zäch, Michael; Christenson, Hugo K.

    2008-10-01

    Cyclohexane allowed to capillary condense from vapor in an annular wedge pore of mica in a surface force apparatus (SFA) remains liquid down to at least 14K below the bulk melting-point Tm. This is an example of supercooling of a liquid due to confinement, like melting-point depression in porous media. In the wedge pore, however, the supercooled liquid is in equilibrium with vapor, and the amount of liquid (and thereby the radius of curvature r of the liquid-vapor interface) depends on the surface tension γLV of the liquid, not the interfacial tension between the solid and liquid. At coexistence r is inversely proportional to the temperature depression ΔT below Tm, in accordance with a recently proposed model [P. Barber, T. Asakawa, and H. K. Christenson, J. Phys. Chem. C 111, 2141 (2007)]. We have now extended this model to include effects due to the temperature dependence of both the surface tension and the enthalpy of melting. The predictions of the improved model have been quantitatively verified in experiments using both a Mark IV SFA and an extended surface force apparatus (eSFA). The three-layer interferometer formed by the two opposing, backsilvered mica surfaces in a SFA was analyzed by conventional means (Mark IV) and by fast spectral correlation of up to 40 fringes (eSFA). We discuss the absence of freezing in the outermost region of the wedge pore down to 14K below Tm and attribute it to nonequilibrium (kinetic) supercooling, whereas the inner region of the condensate is thermodynamically supercooled.

  14. Interpretation and inverse analysis of the wedge splitting test

    DEFF Research Database (Denmark)

    Østergaard, Lennart; Stang, Henrik

    2002-01-01

    Determination of the stress-crack opening relationship, s(w) a material parameter in the fictitious crack model by Hillerborg has proven to be problematic and is still not a simple task to perform. However, this paper demonstrates that the cracked non-linear hinge model by Olesen may be applied...... to the wedge splitting test and that it is well suited for the interpretation of test results in terms of s(w). A fine agreement between the hinge and FEM-models has been found. It has also been found that the test and the hinge model form a solid basis for inverse analysis. The paper also discusses possible...

  15. Heat conduction problem of an evaporating liquid wedge

    Directory of Open Access Journals (Sweden)

    Tomas Barta

    2015-02-01

    Full Text Available We consider the stationary heat transfer near the contact line of an evaporating liquid wedge surrounded by the atmosphere of its pure vapor. In a simplified setting, the problem reduces to the Laplace equation in a half circle, subject to a non-homogeneous and singular boundary condition. By classical tools (conformal mapping, Green's function, we reformulate the problem as an integral equation for the unknown Neumann boundary condition in the setting of appropriate fractional Sobolev and weighted space. The unique solvability is then obtained by means of the Fredholm theorem.

  16. Magmatism significantly alters the thermal structure of the wedge

    Science.gov (United States)

    Rees Jones, D. W.; Katz, R. F.; Rudge, J. F.; Tian, M.

    2016-12-01

    The temperature structure of the mantle wedge is typically modelled as a balance between thermal diffusion and advection by the solid mantle [e.g., 1]. The thermal state of the wedge promotes melting and melt transport in the natural system, but the thermal consequences of these processes have been neglected from previous models. We show that advective transport of sensible and latent heat by liquid magma can locally alter the temperature structure from canonical models by up to 200K. Liquids are liberated from the subducting slab by de-volatilization reactions. They trigger melting and become silicic en route to the surface, where they cause arc volcanism. These liquids transport heat advectively, and consume or supply latent heat as they melt or freeze. To analyse these effects, we parameterise melting in the presence of volatile species. We combine this with a one-dimensional "melting-column model," previously used to understand mid-ocean ridge volcanism. Our calculations highlight the thermal and chemical response to melt transport across the mantle wedge. Finally, we solve two-dimensional geodynamic models with a prescribed slab flux [2]. These models allow us to identify the most thermally significant fluxes of melt in the system. Perturbations of 200K are found at the base of the overriding lithosphere. This thermal signature of melt migration should be considered when interpreting heat flow, petrologic and seismic data [e.g., 3]. Such a thermal perturbation is likely to affect the chemistry of arc volcanoes, the solid mantle flow and, perhaps, the location of the volcanos themselves [4]. [1] van Keken, P. E., Currie, C., King, S. D., Behn, M. D., Cagnioncle, A., He, J., et al. (2008). A community benchmark for subduction zone modeling. PEPI, doi:10.1016/j.pepi.2008.04.015 [2] Wilson, C. R., Spiegelman, M., van Keken, P. E., & Hacker, B. R. (2014). Fluid flow in subduction zones: The role of solid rheology and compaction pressure. EPSL, doi:10.1016/j

  17. Decollement controls on pro versus retro wedge deformation in mountain belts

    Science.gov (United States)

    Grool, Arjan; Huismans, Ritske S.; Ford, Mary

    2017-04-01

    Doubly vergent orogens have a pro-wedge (lower plate) and a retro-wedge (upper plate). Most shortening is accommodated on the pro-wedge while retro-wedge shortening is typically limited. For example, the Eastern Pyrenees have experienced about 145 km of convergence, of which about 125 km (86%) was accommodated in the pro-wedge and about 20 km (14%) in the retro-wedge. Strain partitioning between pro- and retro-wedge is influenced by several factors, some of which have been identified in past work: Extensional inheritance and syn-orogenic sedimentation can help to increase the percentage of total shortening accommodated in the retro-wedge while erosion promotes pro-wedge shortening. We use high-resolution 2D numerical models to investigate factors that control pro- versus retro-wedge shortening. For a total convergence similar to the Eastern Pyrenees, our models predict that variations in extensional inheritance and syn-orogenic sedimentation will result in a maximum of 10% of total shortening being accommodated in the retro-wedge. Here, we investigate the role of 1) the rheology and 2) distribution of a decollement layer. Our models show that: 1) Decollement rheology has a first order control on strain distribution between the pro- and the retro-wedge. After 145 km of total convergence, a model with a weak frictional (φ=2, shale-like) decollement will only accommodate 9% of total shortening in the retro-wedge. In contrast in models with a weak viscous (μ=1018, salt-like) decollement retro-wedge shortening amounts to 18% and a stronger, but still weak, viscous decollement (μ=1019) leads to 21%. 2) Décollement distribution influences the timing of the first outward propagation of thick-skinned deformation in the retro-wedge. In the Eastern Pyrenees, thick-skinned deformation propagated out into the retro-wedge within 145 km of total convergence. In models with a decollement on both sides of the orogen this only occurred after 240 km. If, as in the Eastern

  18. Stable Fixation of a Cementless, Proximally Coated, Double Wedged, Double Tapered Femoral Stem in Total Hip Arthroplasty

    DEFF Research Database (Denmark)

    Nebergall, Audrey K; Rolfson, Ola; Rubash, Harry E

    2016-01-01

    ) agreed to participate in this prospective RSA study. All patients received a Taperloc stem. Tantalum beads were inserted into the femoral bone surrounding the stem to measure migration using RSA. RSA films, plain radiograph, and PROM follow-up were obtained immediately after surgery, 6 months, 1, 2, 3...

  19. Effects of altering heel wedge properties on gait with the Intrepid Dynamic Exoskeletal Orthosis.

    Science.gov (United States)

    Ikeda, Andrea J; Fergason, John R; Wilken, Jason M

    2017-09-01

    The Intrepid Dynamic Exoskeletal Orthosis is a custom-made dynamic response carbon fiber device. A heel wedge, which sits in the shoe, is an integral part of the orthosis-heel wedge-shoe system. Because the device restricts ankle movement, the system must compensate to simulate plantarflexion and allow smooth forward progression during gait. To determine the influence of wedge height and durometer on the walking gait of individuals using the Intrepid Dynamic Exoskeletal Orthosis. Repeated measures. Twelve individuals walked over level ground with their Intrepid Dynamic Exoskeletal Orthosis and six different heel wedges of soft or firm durometer and 1, 2, or 3 cm height. Center of pressure velocity, joint moments, and roll-over shape were calculated for each wedge. Height and durometer significantly affected time to peak center of pressure velocity, time to peak internal dorsiflexion and knee extension moments, time to ankle moment zero crossing, and roll-over shape center of curvature anterior-posterior position. Wedge height had a significant influence on peak center of pressure velocity, peak dorsiflexion moment, time to peak knee extension moment, and roll-over shape radius and vertical center of curvature. Changes in wedge height and durometer systematically affected foot loading. Participants preferred wedges which produced ankle moment zero crossing timing, peak internal knee extension moment timing, and roll-over shape center of curvature anterior-posterior position close to that of able-bodied individuals. Clinical relevance Adjusting the heel wedge is a simple, straightforward way to adjust the orthosis-heel wedge-shoe system. Changing wedge height and durometer significantly alters loading of the foot and has great potential to improve an individual's gait.

  20. Three-dimensional shock wave configurations induced by two asymmetrical intersecting wedges in supersonic flow

    Science.gov (United States)

    Xiang, G.; Wang, C.; Teng, H.; Jiang, Z.

    2017-09-01

    This study explores the three-dimensional (3D) wave configurations induced by 3D asymmetrical intersecting compression wedges in supersonic and hypersonic inviscid flows. By using the "spatial dimension reduction" approach, the problem of 3D steady shock/shock interaction is converted to that of the interaction of two moving shock waves in the characteristic two-dimensional (2D) plane. Shock polar theory is used to analyze the shock configurations in asymmetrical situations. The results show that various shock configurations exist in 3D asymmetrical shock wave interactions, including regular interaction, transitioned regular interaction, single Mach interaction, inverse single Mach interaction, transitional double Mach interaction, weak shock interaction, and weak single Mach interaction. All of the above 3D steady shock/shock interactions have their corresponding 2D moving shock/shock interaction configurations. Numerical simulations are performed by solving the 3D inviscid Euler equations with the non-oscillatory, non-free parameters, dissipative (NND) numerical scheme, and good agreement with the theoretical analysis is obtained. Furthermore, the comparison of results show that the concept of the "virtual wall" in shock dynamics theory is helpful for understanding the mechanism of two-dimensional shock/shock interactions.

  1. Current issues in the design and analysis of stepped wedge trials.

    Science.gov (United States)

    Hughes, James P; Granston, Tanya S; Heagerty, Patrick J

    2015-11-01

    The use of stepped wedge designs in cluster-randomized trials and implementation studies has increased rapidly in recent years but there remains considerable debate regarding the merits of the design. We discuss three key issues in the design and analysis of stepped wedge trials - time-on-treatment effects, treatment effect heterogeneity and cohort studies. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Optimization of parameters on material removal rate in micro-WEDG ...

    African Journals Online (AJOL)

    In this work, an orthogonal array, signal to noise (S/N) ratio and Pareto analysis of variance (ANOVA) are employed to analyze the effect of the micro-WEDG parameters such as feed rate, capacitance and voltage on MRR. This paper focuses on the Taguchi technique for the optimization in micro-WEDG process to achieve ...

  3. Triangular metal wedges for subwavelength plasmon-polariton guiding at telecom wavelengths

    DEFF Research Database (Denmark)

    Boltasseva, Alexandra; Volkov, V.S.; Nielsen, Rasmus Bundgaard

    2008-01-01

    We report on subwavelength plasmon-polariton guiding by triangular metal wedges at telecom wavelengths. A high-quality fabrication procedure for making gold wedge waveguides, which is also mass- production compatible offering large-scale parallel fabrication of plasmonic components, is developed...

  4. Preliminary analysis of coil wedge dimensional variation in SSC Prototype Dipole Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Pollock, D.; Brown, G.; Dwyer, S.; Gattu, R.; Warner, D.

    1993-05-01

    The wedges used in SSC Prototype Dipole Magnets determine the relative position of conductor blocks within magnet coils. They serve to compensate partially for the less than full keystoning of the superconductor cable and to adjust current distribution with azimuth to determine the magnetic field shape. The ability to control the size and uniformity of wedges therefore is an important factor influencing magnet quality. This paper presents preliminary results of a Statistical Quality Control study of wedge dimensional variation and predicted field quality. Dimensions of samples from outer wedges for magnet DCA102 have been measured using a programmable optical comparator. The data is used to evaluate wedge manufacturing process capability, wedge uniformity, and to predict changes in conductor block position due to wedge deviation. Expected multipole variation attributable to observed wedge variation is discussed. This work focuses on a Prototype Dipole Magnet being built at the SSCL Magnet Development Laboratory (SSCL MDL) in Waxahachie, Texas. The magnet is of the same design as the DCA3xx series magnets built at Fermi National Accelerator Laboratory (FNAL) in 1991--92 and later used in the 1992 Accelerator Systems String Test (ASST).

  5. Dissolved organic carbon loss from Yedoma permafrost amplified by ice wedge thaw

    Science.gov (United States)

    Vonk, J. E.; Mann, P. J.; Dowdy, K. L.; Davydova, A.; Davydov, S. P.; Zimov, N.; Spencer, R. G. M.; Bulygina, E. B.; Eglinton, T. I.; Holmes, R. M.

    2013-09-01

    Pleistocene Yedoma permafrost contains nearly a third of all organic matter (OM) stored in circum-arctic permafrost and is characterized by the presence of massive ice wedges. Due to its rapid formation by sediment accumulation and subsequent frozen storage, Yedoma OM is relatively well preserved and highly biologically available (biolabile) upon thaw. A better understanding of the processes regulating Yedoma degradation is important to improve estimates of the response and magnitude of permafrost carbon feedbacks to climate warming. In this study, we examine the composition of ice wedges and the influence of ice wedge thaw on the biolability of Yedoma OM. Incubation assays were used to assess OM biolability, fluorescence spectroscopy to characterize the OM composition, and potential enzyme activity rates to examine the controls and regulation of OM degradation. We show that increasing amounts of ice wedge melt water in Yedoma-leached incubations enhanced the loss of dissolved OM over time. This may be attributed to the presence of low-molecular weight compounds and low initial phenolic content in the OM of ice wedges, providing a readily available substrate that promotes the degradation of Yedoma OC. The physical vulnerability of ice wedges upon thaw (causing irreversible collapse), combined with the composition of ice wedge-engrained OM (co-metabolizing old OM), underlines the particularly strong potential of Yedoma to generate a positive feedback to climate warming relative to other forms of non-ice wedge permafrost.

  6. Varying frontal thrust spacing in mono-vergent wedges: An insight ...

    Indian Academy of Sciences (India)

    Sandbox experiments are used to study frontal thrust fault spacing, which is a function of physical properties within the thrust wedge. We consider three styles of thrust progression in mono-vergent wedges: Style I, II and III. In Style I, frontal thrusts progress forelandward, maintaining a constant spacing, whereas Style II and ...

  7. Reflection of a converging cylindrical shock wave segment by a straight wedge

    Science.gov (United States)

    Gray, B.; Skews, B.

    2017-07-01

    As a converging cylindrical shock wave propagates over a wedge, the shock wave accelerates and the angle between the shock wave and the wedge decreases. This causes the conditions at the reflection point to move from what would be the irregular reflection domain for a straight shock wave into the regular reflection domain. This paper covers a largely qualitative study of the reflection of converging shock wave segments with Mach numbers between 1.2 and 2.1 by wedges inclined at angles between 15° and 60° from experimental and numerical results. The sonic condition conventionally used for predicting the type of reflection of straight shock waves was found to also be suitable for predicting the initial reflection of a curved shock wave. Initially regular reflections persisted until the shock was completely reflected by the wedge, whereas the triple point of initially irregular reflections was observed to return to the wedge surface, forming transitioned regular reflection. After the incident shock wave was completely reflected by the wedge, a shock wave focusing mechanism was observed to amplify the pressure on the surface of the wedge by a factor of up to 100 for low wedge angles.

  8. Wedge factor constituents of high energy photon beams: field size and depth dependence.

    Science.gov (United States)

    Heukelom, S; Lanson, J H; Mijnheer, B J

    1994-01-01

    Wedge factors have been determined as a function of field size and phantom depth for a 60Co gamma-ray beam and X-ray beams in the range from 4 MV to 25 MV. The results show an increase of the wedge factor with field size, up to 9.1% for the 25 MV X-ray beam. The magnitude of this increase is a linear function of the product of that part of the irradiated wedge volume that can be observed from the point of measurement, its mass energy-absorption coefficient and mass density. This relationship is independent of the photon beam energy, the type of wedge material and the wedge angle. Differences in variation of the amount of backscatter to the monitor with field size for the open and wedged photon beam yielded only a minor influence, up to 0.7%. For the 4-16 MV X-ray beams the wedge factor increases linearly with phantom depth, almost independently of field size. For the 60Co gamma-ray beam and the 25 MV X-ray beam the wedge factor variation is a more complicated function of phantom depth for a particular field size.

  9. Static response of maximally pronated and nonmaximally pronated feet to frontal plane wedging of foot orthoses.

    Science.gov (United States)

    Pascual Huerta, Javier; Ropa Moreno, Juan Manuel; Kirby, Kevin A

    2009-01-01

    Research on foot orthoses has shown that their effect on the kinematics of the rearfoot is variable, with no consistent patterns of changes being demonstrated. It has also been hypothesized that the mechanical effect of foot orthoses could be subject specific. The purpose of our study was to determine if maximally pronated feet have a different response to frontal plane wedging of foot orthoses than do nonmaximally pronated feet during static stance. One hundred six feet of 53 healthy asymptomatic subjects were divided into two groups (maximally pronated and nonmaximally pronated) on the basis of their subtalar joint rotational position during relaxed bipedal stance. Functional foot orthoses were constructed for each subject and the relaxed calcaneal stance position was measured while standing on five separate frontal plane orthosis wedging conditions, 10 degrees valgus, 5 degrees valgus, no wedging, 5 degrees varus, and 10 degrees varus, to assess changes in calcaneal position. Relative to the no-wedging condition, there were statistically significant differences (P feet with the 10 degrees valgus and the 10 degrees varus wedging conditions. No significant differences in calcaneal position were found with the 5 degrees varus and the 5 degrees valgus wedging conditions. Our study shows that the response to foot orthoses is variable between individuals. Maximally pronated subjects do not exhibit the same response to frontal plane wedging of foot orthoses as do nonmaximally pronated with 10 degrees wedging. Intrinsic biomechanical factors such as subtalar joint position may influence the response to foot orthoses.

  10. A semi-infinite crack of mode III in the bimaterial wedge

    Directory of Open Access Journals (Sweden)

    Victor V. Tikhomirov

    2016-06-01

    Full Text Available An exact solution of the antiplane problem for a semi-infinite interface crack in a piecewise-homogeneous wedge under a self-balanced load on its sides has been obtained. Three types of boundary conditions on the wedge sides were examined: the both sides being stress-free; both sides being clamped, and one side being stress-free with the second one clamped. As a result of using the Wiener–Hopf method, the solution was represented in quadratures. Green's functions were obtained for stress intensity factors; in the case of a geometrically symmetrical wedge structure simple formulae were found for these functions. The stress singularity in the apex of the wedge was studied. In contrast to the homogeneous wedge structure the asymptotic of the stresses near the apex was established to have sometimes two singular terms for some values of the composite parameters.

  11. Improved wedge method for the measurement of sub-millimeter slice thicknesses in magnetic resonance imaging.

    Science.gov (United States)

    Kanazawa, Tsutomu; Ohkubo, Masaki; Kondo, Tatsuya; Miyazawa, Takayuki; Inagawa, Shoichi

    2017-12-01

    The standard method for measuring the slice thickness of magnetic resonance images uses the inclined surface of a wedge (wedge method); it is sensitive to small increases in noise because of the differentiation of the edge response function (ERF) required. The purpose of this study was to improve the wedge method by fitting a curve to the ERF. The curve-fit function was obtained by convolving an ideal ERF (a ramp function) with a Gaussian function to represent ERF blurring. Measurements of 5- and 3-mm slice thicknesses were performed on a 3T scanner using the conventional wedge method, the improved wedge method, and another standard method using an inclined slab (slab method). Subsequently, 0.5- and 0.25-mm slice thicknesses from multiple slices acquired using a three-dimensional sequence were measured using the improved wedge method. When measuring 5-mm slices, the differences in measurements obtained using the improved wedge method and the conventional slab and wedge methods were very small: <0.6% of the 5-mm slice thickness. The difference was ≤1.7% for 3-mm slices. For 0.5- and 0.25-mm slices, the mean values obtained using the improved wedge method were 0.543 ± 0.007 mm and 0.247 ± 0.015 mm, with a 1.2 and 5.9% coefficient of variation across slices, respectively. The improved wedge method is valid and potentially applicable to the measurement of sub-millimeter slice thicknesses.

  12. Metamaterials based on wedge-shaped electrodynamic structures

    Directory of Open Access Journals (Sweden)

    Mitrokhin Vladimir

    2017-01-01

    Full Text Available The paper studies a possibility of simulation of artificial composite media with negative values of the real part of the equivalent dielectric (magnetic permittivity, by the use of segments of hollow composite waveguides with cylindrical guided waves in evanescent mode. Reactive evanescent fields of wedge-shaped waveguide eigenmodes are formed in the evanescent region before the critical section of the waveguide which separates the quasistatic field region from the distributing field of the evanescent waveguide mode. The possibility of simulation is determined by the equivalence of dispersion equation of the eigenmode propagation constant and the dispersion equation for the electric (magnetic permittivity of plasma-like medium if cut-off frequency and electric (magnetic plasma frequency of the medium are equal.

  13. Two-dimensional electronic spectroscopy with birefringent wedges

    Energy Technology Data Exchange (ETDEWEB)

    Réhault, Julien; Maiuri, Margherita; Oriana, Aurelio; Cerullo, Giulio [IFN-CNR, Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano (Italy)

    2014-12-15

    We present a simple experimental setup for performing two-dimensional (2D) electronic spectroscopy in the partially collinear pump-probe geometry. The setup uses a sequence of birefringent wedges to create and delay a pair of phase-locked, collinear pump pulses, with extremely high phase stability and reproducibility. Continuous delay scanning is possible without any active stabilization or position tracking, and allows to record rapidly and easily 2D spectra. The setup works over a broad spectral range from the ultraviolet to the near-IR, it is compatible with few-optical-cycle pulses and can be easily reconfigured to two-colour operation. A simple method for scattering suppression is also introduced. As a proof of principle, we present degenerate and two-color 2D spectra of the light-harvesting complex 1 of purple bacteria.

  14. The Cimmerian accretionary wedge of Anarak, Central Iran

    Science.gov (United States)

    Zanchi, Andrea; Malaspina, Nadia; Zanchetta, Stefano; Berra, Fabrizio; Benciolini, Luca; Bergomi, Maria; Cavallo, Alessandro; Javadi, Hamid Reza; Kouhpeyma, Meyssam

    2015-04-01

    The occurrence in Iran of several ophiolite belts dating between Late Palaeozoic to Triassic poses several questions on the possible existence of various sutures marking the closure of the Palaeotethys ocean between Eurasia and this Gondwana-derived microplate. In this scenario, the Anarak region in Central Iran still represents a conundrum. Contrasting geochronological, paleontological, paleomagnetic data and reported field evidence suggest different origins for the Anarak Metamorphic Complex (AMC). The AMC is either interpreted, as: (1) relict of an accretionary wedge developed at the Eurasia margin during the Palaeotethys subduction as part of the Cimmerian suture zone of NE Iran, displaced to Central Iran by a large counter-clockwise rotation of the central Iranian blocks; (2) autochthonous unit forming a secondary branch of the main suture zone. Our structural, petrographic and geochemical data indicate that the AMC consists of several metamorphic units also including dismembered "ophiolites" which display different tectono-metamorphic evolutions. Three main ductile deformational events can be distinguished in the AMC. The Morghab and Chah Gorbeh complexes preserve a different M1 metamorphism, characterized by blueschist relics in the S1 foliation of the former unit, and greenschist assemblages in the latter. They share a subsequent similar D2 deformational and M2 metamorphic history, showing a prograde metamorphism with syn- to post-deformation growth of blueschist facies mineral assemblages on pre-existing greenschist facies associations. High pressure, low temperature (HP/LT) metamorphism responsible for the growth of sodic amphibole has been recognized also within marble lenses at the contact between the Chah Gorbeh Complex and serpentinites. Evidence of HP/LT metamorphism also occurs in glaucophane-bearing meta-pillow lavas and serpentinites, which contain antigorite and form most of the "ophiolites" within the AMC. Structural relationships show that the

  15. The Substorm Current Wedge: Further Insights from MHD Simulations

    Science.gov (United States)

    Birn, J.; Hesse, M.

    2015-01-01

    Using a recent magnetohydrodynamic simulation of magnetotail dynamics, we further investigate the buildup and evolution of the substorm current wedge (SCW), resulting from flow bursts generated by near-tail reconnection. Each flow burst generates an individual current wedge, which includes the reduction of cross-tail current and the diversion to region 1 (R1)-type field-aligned currents (earthward on the dawn and tailward on the duskside), connecting the tail with the ionosphere. Multiple flow bursts generate initially multiple SCW patterns, which at later times combine to a wider single SCW pattern. The standard SCWmodel is modified by the addition of several current loops, related to particular magnetic field changes: the increase of Bz in a local equatorial region (dipolarization), the decrease of |Bx| away from the equator (current disruption), and increases in |By| resulting from azimuthally deflected flows. The associated loop currents are found to be of similar magnitude, 0.1-0.3 MA. The combined effect requires the addition of region 2 (R2)-type currents closing in the near tail through dawnward currents but also connecting radially with the R1 currents. The current closure at the inner boundary, taken as a crude proxy of an idealized ionosphere, demonstrates westward currents as postulated in the original SCW picture as well as North-South currents connecting R1- and R2-type currents, which were larger than the westward currents by a factor of almost 2. However, this result should be applied with caution to the ionosphere because of our neglect of finite resistance and Hall effects.

  16. Elderly donors double kidney transplantation (DKT)

    OpenAIRE

    Méndez-Chacón, Pedro; Facultad de Medicina, UNMSM. Lima, Perú; Servicio Nefrología. Servicio de Patología. Hospital Nacional Edgardo Rebagliati Martins. Lima, Perú; Vidalón, Armando; Facultad de Medicina, UNMSM. Lima, Perú; Servicio Nefrología. Servicio de Patología. Hospital Nacional Edgardo Rebagliati Martins. Lima, Perú; Medina, Mario; Servicio Nefrología. Servicio de Patología. Hospital Nacional Edgardo Rebagliati Martins. Lima, Perú; Camacho, Miguel; Servicio Nefrología. Servicio de Patología. Hospital Nacional Edgardo Rebagliati Martins. Lima, Perú; Somocurcio, José; Servicio Nefrología. Servicio de Patología. Hospital Nacional Edgardo Rebagliati Martins. Lima, Perú

    2013-01-01

    Objective: To use both kidneys of an elderly donor in the same receptor and remark the importance of kidney histology as selector method. Materials and Methods: We evaluate the selection and surveillance of 11 patients who received double kidney of cadaver elderly donors. The ten donors’ mean serum creatinine was 1,3 mg/dL, and the mean age was 63 years old (range 56 to 73 years), the receptor’s mean age 53 years. Both kidneys were examined by frozen wedge biopsy. Quantification of damaged ti...

  17. Vertebral body or intervertebral disc wedging: which contributes more to thoracolumbar kyphosis in ankylosing spondylitis patients?

    Science.gov (United States)

    Liu, Hao; Qian, Bang-Ping; Qiu, Yong; Wang, Yan; Wang, Bin; Yu, Yang; Zhu, Ze-Zhang

    2016-01-01

    Abstract Both vertebral body wedging and disc wedging are found in ankylosing spondylitis (AS) patients with thoracolumbar kyphosis. However, their relative contribution to thoracolumbar kyphosis is not fully understood. The objective of this study was to compare different contributions of vertebral and disc wedging to the thoracolumbar kyphosis in AS patients, and to analyze the relationship between the apical vertebral wedging angle and thoracolumbar kyphosis. From October 2009 to October 2013, a total of 59 consecutive AS patients with thoracolumbar kyphosis with a mean age of 38.1 years were recruited in this study. Based on global kyphosis (GK), 26 patients with GK < 70° were assigned to group A, and the other 33 patients with GK ≥ 70° were included in group B. Each GK was divided into disc wedge angles and vertebral wedge angles. The wedging angle of each disc and vertebra comprising the thoracolumbar kyphosis was measured, and the proportion of the wedging angle to the GK was calculated accordingly. Intergroup and intragroup comparisons were subsequently performed to investigate the different contributions of disc and vertebra to the GK. The correlation between the apical vertebral wedging angle and GK was calculated by Pearson correlation analysis. The duration of disease and sex were also recorded in this study. With respect to the mean disease duration, significant difference was observed between the two groups (P < 0.01). The wedging angle and wedging percentage of discs were significantly higher than those of vertebrae in group A (34.8° ± 2.5° vs 26.7° ± 2.7°, P < 0.01 and 56.6% vs 43.4%, P < 0.01), whereas disc wedging and disc wedging percentage were significantly lower than vertebrae in group B (37.6° ± 7.0° vs 50.1° ± 5.1°, P < 0.01 and 42.7% vs 57.3%, P < 0.01). The wedging of vertebrae was significantly higher in group B than in group A (50.1° ± 5.1° vs 26.7° ± 2.7°, P < 0

  18. Mechanism of bone incorporation of beta-TCP bone substitute in open wedge tibial osteotomy in patients.

    NARCIS (Netherlands)

    Gaasbeek, R.D.A.; Toonen, H.G.; Heerwaarden, R.J. van; Buma, P.

    2005-01-01

    A histological study was performed of bone biopsies from 16 patients (17 biopsies) treated with open wedge high tibial osteotomies for medial knee osteoarthritis. The open wedge osteotomies were filled with a wedge of osteoconductive beta tricalcium phosphate (beta-TCP) ceramic bone replacement. At

  19. 76 FR 52313 - Heavy Forged Hand Tools (i.e., Axes & Adzes, Bars & Wedges, Hammers & Sledges, and Picks...

    Science.gov (United States)

    2011-08-22

    ... International Trade Administration Heavy Forged Hand Tools (i.e., Axes & Adzes, Bars & Wedges, Hammers & Sledges... & Adzes, Bars & Wedges, Hammers & Sledges, and Picks & Mattocks) (``Hand Tools'') from the People's... & Wedges, Hammers & Sledges, and Picks & Mattocks) From the People's Republic of China: Final Results of...

  20. [Posterior spinal transpedicular wedge osteotomy for kyphosis due to delayed osteoporotic vertebral fracture in elderly].

    Science.gov (United States)

    Yang, Bao-hui; Li, Hao-peng; He, Xi-jing; Zhang, Chun; Qing, Jie

    2015-08-01

    To evaluate the clinical effects of posterior spinal transpedicular wedge osteotomy for kyphosis due to delayed osteoporotic vertebral fracture in elderly. From July 2009 to February 2014,26 patients with kyphosis caused by delayed osteoporotic vertebral fracture were treated with transpedicular wedge osteotomy. There were 10 males and 16 females,aged from 55 to 75 years old with an average of 67 years. There were 1 osteotomy in thoracic vertebra,21 osteotomies in thoracolumbar vertebrae and 4 in lumbar vertebrae. Total 29 vertebrae were involved, 23 cases with single vertebral fracture and 3 cases with double vertebral fractures. Preoperative Cobb angles were 32°~51° with the mean of (42.00 ± 4.75) ° and VAS scores were 6 to 9 points with an average of (8.40 ± 0.75) points. According to the Frankel grade of spinal cord function, 4 cases were grade D and 22 cases were grade E. Intraoperative bleeding, operation time and perioperative complications were recorded, and improvements of Cobb angle were evaluated by X-rays. VAS score and Frankel grade were respectively used to evaluate the pain and nerve function. The average operation time were 155 min (ranged, 120 to 175) and the mean intraoperative bleeding were 1 100 ml (ranged,800 to 1 500). Postoperative at 2 days, Cobb angle and VAS score were (9.60 ± 2.50) ° and (4.00 ± 1.00) points, respectively, ranged from 5° to 15° and 1 to 5 points. VAS score and Cobb angle improved obviously compared with preoperative (P Cobb angle was 76%. Frankel grade of 1 case changed from grade E to C, and the others did not become worse. The follow-up period ranged from 3 to 24 months with an average of 16.4 months. At the final follow-up, Cobb angles and VAS score were (11.00 ± 3.50)° and (4.40 ± 1.25) points, respectively, ranged from 5° to 19° and 1 to 6 points. The patient whose Frankel grade E changed to C at 2 days after surgery and changed to grade D at the latest follow-up. Vertebral body fracture below the

  1. Statistical mechanics of fluids adsorbed in planar wedges: finite contact angle.

    Science.gov (United States)

    Henderson, J R

    2004-06-01

    I consider the statistical mechanics of inhomogeneous fluids applied to fluids adsorbed in planar wedges. Exact results are described that belong to an infinite subset of models defined as the intersection of any two identical semi-infinite planar wall-fluid potentials. This geometry is interesting as a generic example of adsorption onto structured interfaces and of interfacial phase transitions controlled by the substrate geometry. Previously described virial theorems are extended to the case of a general wall-fluid model. This enables the consideration of wedge filling when Young's contact angle far from the wedge apex is finite. The virial theorems generate two important relations: the wedge sum rules. The first sum rule links the interfacial free energy far from the wedge apex to the structure induced at the apex. The second sum rule links the free energy of the apex region to the structure induced by the apex. When Young's contact angle at the wedge walls is finite these relations further yield an exact result for the macroscopic contact angle in terms of the nanoscopic structure at the three-phase contact line (the intersection of the liquid-vapor surface with a wedge wall): the contact angle sum rule. These exact results are of direct relevance to computer simulation studies of adsorbed films. In addition, they take on special significance in the vicinity of continuous interfacial phase transitions: an approach to complete filling and the filling transition at bulk liquid-vapor coexistence.

  2. Onset of flow separation for the oblique water impact of a wedge

    Science.gov (United States)

    Semenov, Yuriy A.; Yoon, Bum-Sang

    2009-11-01

    For the oblique impact of a wedge on a liquid half space, the limiting angles of the entry velocity and the wedge orientation corresponding to flow separation from the wedge vertex during the initial stage of the impact are investigated on the basis of an analytical solution of the problem. The liquid is assumed to be ideal and incompressible; gravity, surface tension, and air cushioning effects are ignored. The flow generated by the impact is two dimensional and potential. The solution is presented in terms of two governing expressions, which are the complex velocity and the derivative of the complex potential defined in a parameter region. These expressions are obtained using generalized integral formulas for solving mixed and uniform boundary-value problems for the first quadrant. They include two unknown functions, which are the velocity magnitude and angle to the free surface determined from the dynamic and kinematic boundary conditions. The obtained system of integral equations is solved by using the method of successive approximations. The effect of the horizontal component of the entry velocity is studied for various wedge orientations. The analysis of the computations revealed configurations of the impact such that the pressure along the whole length of one side of the wedge becomes less than the pressure on the free surface. Although air effects are not included in the analysis, such a pressure distribution provides conditions for the ventilation of the wedge side, which, in the presence of the air, starts from the contact point on the free surface and extends suddenly along the whole length of the wedge side, thus leading to flow separation from the wedge vertex. The theoretical predictions of flow separation and the experimental data on flow separation by Judge et al. ["Initial water impact of a wedge at vertical and oblique angles," J. Eng. Math. 48, 279 (2004)] are remarkably close to each other.

  3. Recent circum-Arctic ice-wedge degradation and its hydrological impacts

    Science.gov (United States)

    Liljedahl, A. K.; Boike, J.; Daanen, R. P.; Fedorov, A. N.; Frost, G. V., Jr.; Grosse, G.; Hinzman, L. D.; Iijima, Y.; Jorgenson, J. C.; Matveyeva, N.; Necsoiu, M.; Raynolds, M. K.; Romanovsky, V. E.; Schulla, J.; Tape, K. D.; Walker, D. A.; Wilson, C. J.; Yabuki, H.; Zona, D.

    2016-12-01

    Ice-wedges are common permafrost features formed over hundreds to thousands of years of repeated frost cracking and ice vein growth. We used field and remote sensing observations to assess changes in areas dominated by ice-wedges, and we simulated the effects of those changes on watershed-scale hydrology. We show that top melting of ice-wedges and subsequent ground subsidence has occurred at multiple sites in the North American and Russian Arctic. At most sites, melting ice-wedges have initially resulted in increased wetness contrast across the landscape, evident as increased surface water in the ice-wedge polygon troughs and somewhat drier polygon centers. Most areas are becoming more heterogeneous with wetter troughs, more small ponds (themokarst pits forming initially at ice-wedge intersections and then spreading along the troughs) and drier polygon centers. Some areas with initial good drainage, such as near creeks, lake margins, and in hilly terrain, high-centered polygons form an overall landscape drying due to a drying of both polygon centers and troughs. Unlike the multi-decadal warming observed in permafrost temperatures, the ice-wedge melting that we observed appeared as a sub-decadal response, even at locations with low mean annual permafrost temperatures (down to -14 °C). Gradual long-term air and permafrost warming combined with anomalously warm summers or deep snow winters preceded the onset of the ice-wedge melting. To assess hydrological impacts of ice-wedge melting, we simulated tundra water balance before and after melting. Our coupled hydrological and thermal model experiments applied over hypothetical polygon surfaces suggest that (1) ice-wedge melting that produces a connected trough-network reduces inundation and increases runoff, and that (2) changing patterns of snow distribution due to differential ground subsidence has a major control on ice-wedge polygon tundra water balance despite an identical snow water equivalent at the landscape

  4. Analysis of distribution rule of surface stress on cross wedge rolling contact zone by finite element method

    Science.gov (United States)

    Shu, Xuedao; Li, Lianpeng; Hu, Zhenghuan

    2005-12-01

    Contact surface of cross-wedge rolling is a complicated space surface and distribution rule of contact surface stress is very complicated. So far, its analyzed result was still based on slippery line method. Designing mould and actual production mainly depend on experiential factor. Application and development of cross-wedge rolling was baffled seriously. Based on the forming characteristics of cross-wedge rolling with flat wedge-shape, the ANSYS/DYNA software was developed secondly on the basis of itself, and the corresponding command program was compiled. Rolling process of cross-wedge rolling with flat wedge-shape was simulated successfully. Through simulation, space surface shape of contact surface was achieved, and distribution rule of contact surface stress was analyzed detailed and obtained. The results provide important theoretical foundation for avoiding appearing bug on surface of rolled part, instructing to design cross-wedge mould and confirming force and energy parameter.

  5. The Seismic Structure of the Mantle Wedge under Cascade Volcanoes

    Science.gov (United States)

    Levander, A.; Liu, K.; Porritt, R. W.; Allen, R. M.

    2011-12-01

    Under a number of Cascade volcanoes we have identified a characteristic seismic signature in individual station Ps receiver functions and in Ps CCP image volumes made from USArray Transportable Array and Flexible Array stations. In the mantle wedge, the CCP images and the RFs show a strong negative event just below the Moho, paired with a weak to moderate positive event between 50-70 km, and a strong slab event. At most of these volcanoes, a strong negative signal also appears between 15 and 25 km depth in the crust. The signature is particularly clear under Mt. Lassen and Mt. Shasta in data from FAME (Flexible Array Mendocino Experiment), where instruments were close to the volcanic centers. Comparing the average Cascadia volcano signature to those of stations throughout the western U.S. and specifically those of the Cascadia backarc region, shows that this signal is unique to the Cascadia volcanoes. Joint inversion of the Ps receiver functions and ambient noise Rayleigh wave phase velocities (Porritt et al., 2011; Liu et al., submitted) for those volcanoes with the paired events provides 1D shear velocity profiles having common characteristics. A strong sub-Moho low velocity zone from 5 to 15 km thick gives rise to the paired negative-positive signals in the receiver functions. The sub-Moho low velocity zones, with velocities of 3.7 CIDER 2011 summer program.

  6. Precision forming machine with rolling plate cross wedge rolling

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Roller cross wedge rolling(CWR)machines have high rigidity, but sector dies are difficult to process. Plate CWR machines have low rigidity and need large floor space, but plate dies are easy to process. Neither roller CWR machine nor plate CWR machine can produce larger workpieces. Based on the above conclusions, this paper presents the mechanical principle of the precision forming machine with rolling plate CWR. Then, its design principle and machine construction are presented. There are a top press roller above the upper sliding plate and a bottom press roller under the lower sliding plate. The press rollers make rolling contact with the sliding plates. The plate dies are mounted on the upper and lower sliding plates, respectively. Furthermore, the axes of both press rollers and centerline of work-piece always keep in the identical vertical plane during forming process. These make the machine retain advantages of high rigidity for roller CWR machine and simpleness of manufacturing dies for plate CWR machine, and abandon defects of poor rigidity for plate CWR machine and difficulty of manufac-turing dies for roller CWR machine. Moreover, the machine can produce larger workpieces.

  7. Medial opening wedge distal femoral osteotomy for post-traumatic secondary knee osteoarthritis.

    Science.gov (United States)

    Matsui, Gen; Akiyama, Takenori; Ikemura, Satoshi; Mawatari, Taro

    2014-04-30

    Osteoarthritis of the knee secondary to femoral fracture is difficult to treat. There are some surgical options, such as total knee arthroplasty or correction osteotomy. Opening wedge high tibial osteotomy is an established treatment of gonarthrosis. However, few reports are available on the effectiveness of a medial opening wedge distal femoral osteotomy. We present a case of a medial opening wedge distal femoral osteotomy on gonarthrosis secondary to a malunited femoral fracture with varus deformity and leg length discrepancy. This osteotomy was performed at the deformed femur, with locking plate fixation and autologous bone graft. Six months after the surgery, the osteotomy site was filled with bridging callus. Two years later, the Knee Society Score improved from 45 to 90 points. Medial opening wedge distal femoral osteotomy can be a useful method to treat knee osteoarthritis associated with distal femoral deformity.

  8. Development of Cone Wedge Ring Expansion Test to Evaluate Mechanical Properties of Clad Tubing Structure

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jy-An John [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-10-01

    To determine the hoop tensile properties of irradiated fuel cladding in a hot cell, a cone wedge ring expansion test method was developed. A four-piece wedge insert was designed with tapered angles matched to the cone shape of a loading piston. The ring specimen was expanded in the radial direction by the lateral expansion of the wedges under the downward movement of the piston. The advantages of the proposed method are that implementation of the test setup in a hot cell is simple and easy, and that it enables a direct strain measurement of the test specimen from the piston’s vertical displacement soon after the wedge-clad contact resistance is initiated.

  9. Critical Coulomb Wedge Theory Applied to Hyper-Extended Rifted Margins: A New Perspective

    Science.gov (United States)

    Nirrengarten, M.; Manatschal, G.; Yuan, X.; Kusznir, N. J.; Maillot, B.

    2016-12-01

    Field studies, borehole data and seismic sections show that hyper-extended domains at magma-poor rifted margins: 1) deform predominantly in the brittle field, 2) form wedge shape terminations of the continental crust, and 3) develop a frictional décollement between the hyper-extended crust and the underlying serpentinized mantle. These three observations are also the three requirements to apply the Critical Coulomb Wedge (CCW) theory, which describes the stability limit of a frictional wedge over a décollement. We measure the surface slope and detachment dip of hyper-extended wedges at magma-poor margins to compare them with the stability envelopes of CCW theory. Our analysis shows that lower plate margins, forming the footwall of the major extensional detachment faults, correspond to gravitational wedges. In contrast upper plate margins, forming the hanging wall of major extensional detachment faults, are tectonic extensional wedges. Dip measurements of the lower plate margins cluster on the CCW stability limits, which implies that lower plate wedges have similar shapes and that they are gravitationally stable. Upper plate margins are more complex and are not always at the critical shape due to the evolution of the underlying detachment dip and re-localization of the deformation on new detachment faults. The architecture of hyper-extended wedges results from the interaction between rocks physical properties (frictional parameters and fluid pressures) and the localization of deformation processes. Interpretation of hyper-extended domains with seismic sections is often complex due to thick post-tectonic sediments or salt layers. The application of CCW theory on hyper-extended rifted margins provides a new framework to interpret the fault pattern and its associated sedimentary architecture. In particular the application of CCW theory can explain the formation of extensional allochthons and continentward dipping faults.

  10. Living on the wedge: female control of paternity in a cooperatively polyandrous cichlid

    OpenAIRE

    Kohda, Masanori; Heg, Dik; Makino, Yoshimi; Takeyama, Tomohiro; Shibata, Jun-ya; Watanabe, Katsutoshi; Munehara, Hiroyuki; Hori, Michio; Awata, Satoshi

    2009-01-01

    Theories suggest that, in cooperatively breeding species, female control over paternity and reproductive output may affect male reproductive skew and group stability. Female paternity control may come about through cryptic female choice or female reproductive behaviour, but experimental studies are scarce. Here, we show a new form of female paternity control in a cooperatively polyandrous cichlid fish (Julidochromis transcriptus), in which females prefer wedge-shaped nesting sites. Wedge-shap...

  11. Corneal wedge excision in the treatment of high astigmatism after penetrating keratoplasty.

    Science.gov (United States)

    Ezra, Daniel G; Hay-Smith, Graham; Mearza, Ali; Falcon, Mike G

    2007-08-01

    To report 5 cases of high astigmatism after penetrating keratoplasty (PK) treated with corneal wedge excisions. We report our experience of 5 patients treated with corneal wedge excisions for high astigmatism after PK. A thin sliver of cornea measuring between 0.1 and 0.2 mm in thickness was excised from just inside the graft-recipient interface. The length of the incision centered at the axis of the flatter meridian of the cornea and was extended over a range of 60-90 degrees. The wound was closed with interrupted 10-0 nylon sutures placed every 15 degrees. We also report, for the first time, both pre- and postoperative corneal topography in 3 of our patients who underwent wedge excisions. The mean preoperative astigmatism was 15.2 D (range, 8.5-29.1 D). Postoperatively, after wedge excision, the mean astigmatism was reduced to 2.3 D (range, 1.9-3.7 D). The mean reduction in astigmatism was 12.9 D (range, 6.3-25.4 D). Corneal wedge resection is an effective treatment for high astigmatism after PK. It may prove particularly useful in cases of high astigmatism or where other treatments are not appropriate. We believe that there is still a role for wedge resection as one of many tools to be used in the treatment of high post-PK astigmatism.

  12. [Research on the transmittance spectrum of wedge thin film filter with oblique incidence].

    Science.gov (United States)

    Yu, Kan; Huang, De-Xiu; Yin, Juan-Juan; Bao, Jia-Qi

    2013-08-01

    Angle-tuned thin film filter is widely used in the DWDM system for its broad tunable wavelength range and high rectangular degree. The transmissivity and the half bandwidth is greatly influenced not only by the incident angle, but also by the wedge angle of the non-paralleled thin film filter. In the present paper, the influences of the wedge angle on the transmissivity and the half bandwidth were detailedly analyzed. The proper wedge angle and the orientation can greatly improve the characteristics of the transmittance spectrum. The angle-tuned thin film filter with 0.8 degrees wedge angle was also fabricated. The experimental results show that keeping the wedge angle with the same orientation to the incident angle will worsen the transmissivity and the rectangular degree of the transmittance spectrum. However, keeping the wedge angle orientation reverse to the incident angle will greatly enhance the transmissivity and the rectangular degree of the filter and its tunable wavelength range will broaden by 10 nm.

  13. On the practice of the clinical implementation of enhanced dynamic wedges.

    Science.gov (United States)

    Koken, Phil W; Heukelom, Stan; Cuijpers, Johan P

    2003-01-01

    Practical aspects of the clinical implementation of enhanced dynamic wedges (EDW) replacing manual wedges are presented and discussed extensively. A comparison between measured and calculated data is also presented. Relative dose distributions and wedge factors were calculated with a commercially available treatment planning system and measured in a water-phantom and with an ionization chamber. Wedge factor calculations and measurements were also compared with an independent method of wedge factor calculations available from the literature. Aspects of the clinical implementation, such as safety and quality assurance, were evaluated. Measurements and calculations agreed very well and were slightly better than results of previous studies. Profiles and percentage depth doses (PDDs) agreed within 1% to 1.5% and within 0.5%, respectively. Measured and calculated wedge factors ratios agreed within 0.5% to 1%. Calculated and measured EDW dose distributions showed excellent agreement, both relative and absolute. However, for safe and practical use, specific aspects need to be taken into consideration. Once the treatment planning system is commissioned properly, the clinical implementation of EDW is rather straightforward.

  14. Focusing of surface phonon-polaritons along conical and wedge polar nanostructures

    Science.gov (United States)

    Gluchko, Sergei; Ordonez-Miranda, Jose; Tranchant, Laurent; Antoni, Thomas; Volz, Sebastian

    2015-08-01

    Focusing of surface phonon-polaritons propagating toward the tip of a cone and the edge of a wedge is theoretically analyzed and compared. Based on Maxwell's equations, explicit expressions for the dispersion relations in each structure are determined and solved numerically for a propagation parameter driving the surface phonon-polariton energy density. For conical and wedge structures of SiO2, it is found that: (1) the cone (wedge) supports the polariton focusing only for aperture angles in the interval 18 ° - 68 ° ( 21 ° - 51 ° ), and within the range of excitation frequencies from 32.1 THz (31.5 THz) to 33.9 THz (33.9 THz). In this frequency interval, the real part of the SiO2 permittivity is negative and the presence of polaritons is significant. (2) The polariton focusing efficiency of both the cone and wedge reaches its maximum values at the critical frequency f cr = 33.6 THz and at different aperture angles of about α opt = 45 ° and α opt = 30 ° , respectively. (3) When the polaritons travel from 100 nm to 5 nm toward the tip of the cone with this optimum angle, their Poynting vector increases by a factor of 12, which is about four times larger than the corresponding one provided by the wedge and indicates that the cone is more efficient than the wedge for the focusing of surface phonon-polaritons.

  15. Poster - Thur Eve - 41: Effect of beam symmetry on enhanced dynamic wedge quality assurance and tolerance levels.

    Science.gov (United States)

    Meyer, T; Hudson, A

    2012-07-01

    Wedged fields are common in three dimensional conformal radiation therapy and require appropriate quality assurance (QA). Currently, our centre calculates the angle of enhanced dynamic wedge (EDW) deliveries with the PROFILER at a monthly frequency but Canadian guidelines on the recommended QA of enhanced dynamic wedges are not available yet. TG-142 recommendations include monthly validation of the central axis wedge factors with only annual verification of wedge profiles. Our monthly QA results have demonstrated a sensitivity of the calculated EDW angle to open beam symmetry. The goal of this work is to compare wedge angle and direct profile comparison as QA measures of EDW delivery and determine appropriate parameter tolerances. The impact of open field symmetry variations on EDW profiles was determined by varying beam symmetry with a test potentiometer and measuring the resulting EDW beam profile with the PROFILER. A calculated wedge angle and direct profile comparison were used to describe the deviations in EDW deliveries. The impact of the deviations on typical plans incorporating wedged fields was evaluated by constructing 'equivalent wedges' to the profile deviations using mixed 60 degree and open field beams and performing plan comparisons in Eclipse. Beam symmetry was observed to have a significant impact on wedge angle for small angle wedges, with a 1% symmetry tolerance allowing a 3.4 degree range of wedge angles for a nominal 10 degree wedge. Direct profile comparison allows a more consistent definition of a dose based tolerance range to be applied without angle dependent tolerances. © 2012 American Association of Physicists in Medicine.

  16. Three-dimensional vertebral wedging in mild and moderate adolescent idiopathic scoliosis.

    Directory of Open Access Journals (Sweden)

    Sophie-Anne Scherrer

    Full Text Available BACKGROUND: Vertebral wedging is associated with spinal deformity progression in adolescent idiopathic scoliosis. Reporting frontal and sagittal wedging separately could be misleading since these are projected values of a single three-dimensional deformation of the vertebral body. The objectives of this study were to determine if three-dimensional vertebral body wedging is present in mild scoliosis and if there are a preferential vertebral level, position and plane of deformation with increasing scoliotic severity. METHODOLOGY: Twenty-seven adolescent idiopathic scoliotic girls with mild to moderate Cobb angles (10° to 50° participated in this study. All subjects had at least one set of bi-planar radiographs taken with the EOS® X-ray imaging system prior to any treatment. Subjects were divided into two groups, separating the mild (under 20° from the moderate (20° and over spinal scoliotic deformities. Wedging was calculated in three different geometric planes with respect to the smallest edge of the vertebral body. RESULTS: Factorial analyses of variance revealed a main effect for the scoliosis severity but no main effect of vertebral Levels (apex and each of the three vertebrae above and below it (F = 1.78, p = 0.101. Main effects of vertebral Positions (apex and above or below it (F = 4.20, p = 0.015 and wedging Planes (F = 34.36, p<0.001 were also noted. Post-hoc analysis demonstrated a greater wedging in the inferior group of vertebrae (3.6° than the superior group (2.9°, p = 0.019 and a significantly greater wedging (p≤0.03 along the sagittal plane (4.3°. CONCLUSIONS: Vertebral wedging was present in mild scoliosis and increased as the scoliosis progressed. The greater wedging of the inferior group of vertebrae could be important in estimating the most distal vertebral segment to be restrained by bracing or to be fused in surgery. Largest vertebral body wedging values obtained in the sagittal plane support

  17. Double Swing

    DEFF Research Database (Denmark)

    Clausen, Lisbeth

    2017-01-01

    There are two main streams of understanding intercultural communication. The “classic” transmission models include the basic elements of communication involved in sending messages from a sender to a receiver. These models enable analysis of all communication elements and effects by focusing...... on sameness in communication. In contrast, Muneo Jay Yoshikawa's “double-swing” model of intercultural communication between the East and West is based on an eastern understanding of dialogue, collaborative communication, and co-creation of meaning. The double-swing model enables an understanding...... of communication as an ongoing encounter where both sender and receiver have mutual respect. It has four modes of communication: the ethnocentric, the dialectic, the control, and the dialogic. Both models have something to offer intercultural communication, but the double-swing model enables a worldview...

  18. The effect of shoe design and lateral wedges on knee load and neuromuscular control in healthy subjects during walking

    DEFF Research Database (Denmark)

    Mølgaard, Carsten; Kersting, Uwe G.

    2014-01-01

    design/type on the effectiveness of lateral wedging has not been investigated so far. The Purpose of the present study was to explore alterations in knee loading due to lateral foot wedges in three different shoes. Methods: Thirteen healthy participants with no history of knee pain were tested using...... wedging is effective regardless of shoe design. Differences between the three neutral walking conditions underline the importance of footwear choice in individuals. It is safe to apply lateral wedges without jeopardising muscular control during walking regardless of shoe type. Possible effects of altering...... three-dimensional gait analysis. Barefoot walking, walking in a running shoe, an Oxford-type leather shoe, and a rocker shoe were analysed. The shoes were tested both with and without a 10-degree full-length laterally wedged insole. Results: There were significant shoe wedge interactions on the first...

  19. Laser-based linear and nonlinear guided elastic waves at surfaces (2D) and wedges (1D).

    Science.gov (United States)

    Hess, Peter; Lomonosov, Alexey M; Mayer, Andreas P

    2014-01-01

    The characteristic features and applications of linear and nonlinear guided elastic waves propagating along surfaces (2D) and wedges (1D) are discussed. Laser-based excitation, detection, or contact-free analysis of these guided waves with pump-probe methods are reviewed. Determination of material parameters by broadband surface acoustic waves (SAWs) and other applications in nondestructive evaluation (NDE) are considered. The realization of nonlinear SAWs in the form of solitary waves and as shock waves, used for the determination of the fracture strength, is described. The unique properties of dispersion-free wedge waves (WWs) propagating along homogeneous wedges and of dispersive wedge waves observed in the presence of wedge modifications such as tip truncation or coatings are outlined. Theoretical and experimental results on nonlinear wedge waves in isotropic and anisotropic solids are presented. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Wedge and spring assembly for securing coils in electromagnets and dynamoelectric machines

    Science.gov (United States)

    Lindner, M.; Cottingham, J.G.

    1996-03-12

    A wedge and spring assembly for use in electromagnets or dynamoelectric machines is disclosed having a housing with an axis therethrough and a plurality of coils supported on salient poles that extend radially inward from the housing toward the housing axis to define a plurality of interpole spaces. The wedge and spring assembly includes a nonmagnetic retainer spring and a nonmagnetic wedge. The retainer spring is formed to fit into one of the interpole spaces, and has juxtaposed ends defining between them a slit extending in a direction generally parallel to the housing axis. The wedge for insertion into the slit provides an outwardly directed force on respective portions of the juxtaposed ends to expand the slit so that respective portions of the retainer spring engage areas of the coils adjacent thereto, thereby resiliently holding the coils against their respective salient poles. The retainer spring is generally triangular shaped to fit within the interpole space, and the wedge is generally T-shaped. 6 figs.

  1. Inactivation of Listeria monocytogenes using Water Bath Heat Treatment in Vacuum Packed Ricotta Salata Cheese Wedges.

    Science.gov (United States)

    Spanu, Carlo; Scarano, Christian; Spanu, Vincenzo; Pala, Carlo; Di Salvo, Riccardo; Piga, Carlo; Ullu, Antonio; Casti, Daniele; Lamon, Sonia; Cossu, Francesca; Ibba, Michela; De Santis, Enrico Pietro Luigi

    2015-07-01

    Ricotta salata cheese is frequently contaminated on the surface with Listeria monocytogenes. Water bath heat treatment in vacuum packed whole ricotta salata cheese wheels demonstrated to be effective in inactivating L. monocytogenes. However, the risk of cross-contamination in ricotta salata wedges is increased during cheese cutting. Therefore, the effectiveness of heat treatment in ricotta salata wedges has to be demonstrated conducting a new validation study. In this study, 9 different time temperature combinations, 75, 85, and 90 °C applied for 10, 20, and 30 min each, were tested on artificially contaminated ricotta salata cheese wedges. The extent of the lethal effect on L. monocytogenes was assessed 1 and 30 d after the application of the hot water bath treatment. Five of 9 combinations, 75 °C for 30 min, 85 °C for 20, and 30 min, and 90°C for 20 and 30 min, demonstrated to meet the process criteria of at least 5 log reduction. Sensory analyses were also conducted in order to account for the potential impact on sensory features of ricotta salata wedges, which showed no significant differences between treatments. This study allowed to select water bath heat treatments of vacuum packed ricotta salata wedges effective to reduce L. monocytogenes contamination. Such treatments can be successfully applied by food business operator to meet compliance with microbiological criteria through the designated shelf-life. © 2015 Institute of Food Technologists®

  2. Slamming pressures on the bottom of a free-falling vertical wedge

    Science.gov (United States)

    Ikeda, C. M.; Judge, C. Q.

    2013-11-01

    High-speed planing boats are subjected to repeat impacts due to slamming, which can cause structural damage and injury to passengers. A first step in understanding and predicting the physics of a craft re-entering the water after becoming partially airborne is an experimental vertical drop test of a prismastic wedge (deadrise angle, β =20° beam, B = 300 mm; and length, L = 600 mm). The acrylic wedge was mounted to a rig allowing it to free-fall into a deep-water tank (5.2m × 5.2m × 4.2m deep) from heights 0 keel to the free surface. The wedge was instrumented to record vertical position, acceleration, and pressure on the bottom surface. A pressure mapping system, capable of measuring several points over the area of the thin (0.1 mm) film sensor at sampling rates up to 20 kHz, is used and compared to surface-mounted pressure transducers (sampled at 10 kHz). A high speed camera (1000 fps, resolution of 1920 × 1200 pixels) is mounted above the wedge model to record the wetted surface as the wedge descended below the free surface. The pressure measurements taken with both conventional surface pressure transducers and the pressure mapping system agree within 10% of the peak pressure values (0.7 bar, typical). Supported by the Office of Naval Research.

  3. Double screening

    Energy Technology Data Exchange (ETDEWEB)

    Gratia, Pierre [Department of Physics, University of Chicago,South Ellis Avenue, Chicago, IL 60637 (United States); Hu, Wayne [Department of Astronomy and Astrophysics, University of Chicago,South Ellis Avenue, Chicago, IL 60637 (United States); Enrico Fermi Institute and Kavli Institute for Cosmological Physics, University of Chicago,South Ellis Avenue, Chicago, IL 60637 (United States); Joyce, Austin [Enrico Fermi Institute and Kavli Institute for Cosmological Physics, University of Chicago,South Ellis Avenue, Chicago, IL 60637 (United States); Ribeiro, Raquel H. [School of Physics and Astronomy, Queen Mary University of London,Mile End Road, London, E1 4NS (United Kingdom)

    2016-06-15

    Attempts to modify gravity in the infrared typically require a screening mechanism to ensure consistency with local tests of gravity. These screening mechanisms fit into three broad classes; we investigate theories which are capable of exhibiting more than one type of screening. Specifically, we focus on a simple model which exhibits both Vainshtein and kinetic screening. We point out that due to the two characteristic length scales in the problem, the type of screening that dominates depends on the mass of the sourcing object, allowing for different phenomenology at different scales. We consider embedding this double screening phenomenology in a broader cosmological scenario and show that the simplest examples that exhibit double screening are radiatively stable.

  4. Achieving Hard X-ray Nanofocusing Using a Wedged Multilayer Laue Lens

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Xiaojing [Brookhaven National Lab. (BNL), Upton, NY (United States); Conley, Raymond [Brookhaven National Lab. (BNL), Upton, NY (United States); Argonne National Lab. (ANL), Argonne, IL (United States); Bouet, Nathalie [Brookhaven National Lab. (BNL), Upton, NY (United States); Zhou, Juan [Brookhaven National Lab. (BNL), Upton, NY (United States); Macrander, Albert [Argonne National Lab. (ANL), Argonne, IL (United States); Maser, Jorg [Argonne National Lab. (ANL), Argonne, IL (United States); Yan, Hanfei [Brookhaven National Lab. (BNL), Upton, NY (United States); Nazaretski, Evgeny [Brookhaven National Lab. (BNL), Upton, NY (United States); Lauer, Kenneth [Brookhaven National Lab. (BNL), Upton, NY (United States); Harder, Ross [Argonne National Lab. (ANL), Argonne, IL (United States); Robinson, Ian K. [Univ. College London, Bloomsbury (United Kingdom); Research Complex at Harwell, Oxfordshire (United Kingdom); Kalbfleisch, Sebastian [Brookhaven National Lab. (BNL), Upton, NY (United States); Chu, Yong S. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-05-04

    Here, we report on the fabrication and the characterization of a wedged multilayer Laue lens for x-ray nanofocusing. The lens was fabricated using a sputtering deposition technique, in which a specially designed mask was employed to introduce a thickness gradient in the lateral direction of the multilayer. X-ray characterization shows an efficiency of 27% and a focus size of 26 nm at 14.6 keV, in a good agreement with theoretical calculations. Our results indicate that the desired wedging is achieved in the fabricated structure. Furthermore, we anticipate that continuous development on wedged MLLs will advance x-ray nanofocusing optics to new frontiers and enrich capabilities and opportunities for hard X-ray microscopy.

  5. Effectiveness of a Wedge Probe to Measure Sonic Boom Signatures in a Supersonic Wind Tunnel

    Science.gov (United States)

    Wilcox, Floyd J., Jr.; Elmiligui, Alaa A.

    2013-01-01

    A wind tunnel investigation was conducted in the Langley Unitary Plan Wind Tunnel (UPWT) to determine the effectiveness of a wedge probe to measure sonic boom pressure signatures compared to a slender conical probe. A generic business jet model at a constant angle of attack and at a single model to probe separation distance was used to generate a sonic boom signature. Pressure signature data were acquired with both the wedge probe and a slender conical probe for comparison. The test was conducted at a Mach number of 2.0 and a free-stream unit Reynolds number of 2 million per foot. The results showed that the wedge probe was not effective in measuring the sonic boom pressure signature of the aircraft model in the supersonic wind tunnel. Data plots and a discussion of the results are presented. No tabulated data or flow visualization photographs are included.

  6. Wedge Shock and Nozzle Exhaust Plume Interaction in a Supersonic Jet Flow

    Science.gov (United States)

    Castner, Raymond; Zaman, Khairul; Fagan, Amy; Heath, Christopher

    2014-01-01

    Fundamental research for sonic boom reduction is needed to quantify the interaction of shock waves generated from the aircraft wing or tail surfaces with the nozzle exhaust plume. Aft body shock waves that interact with the exhaust plume contribute to the near-field pressure signature of a vehicle. The plume and shock interaction was studied using computational fluid dynamics and compared with experimental data from a coaxial convergent-divergent nozzle flow in an open jet facility. A simple diamond-shaped wedge was used to generate the shock in the outer flow to study its impact on the inner jet flow. Results show that the compression from the wedge deflects the nozzle plume and shocks form on the opposite plume boundary. The sonic boom pressure signature of the nozzle exhaust plume was modified by the presence of the wedge. Both the experimental results and computational predictions show changes in plume deflection.

  7. Angular tolerances and trapped internal reflections in wedged high refractive index Brewster's angle plates

    Science.gov (United States)

    Rutt, H. N.

    1997-02-01

    It is well known that the angular alignment tolerance for Brewster's angle plates is not generally strict. It is often not appreciated that for high index plates however wedge tolerances are small. It is shown that in Brewster angle plates of high refractive index materials, small wedge angles in the fabricated plate can cause internal s-plane reflections to become 'trapped' by total internal reflection. A wedge angle acceptable in terms of its p-plane loss can cause such trapped reflections. In laser systems the resulting multiply reflected beams can move sideways in the plate and eventually hit o-ring seals or other mounting arrangements, causing component damage and leaks in unexpected locations. Stray light problems of an unexpected nature can occur from this effect in both laser based and conventional optical devices.

  8. A quantum hybrid with a thin antenna at the vertex of a wedge

    Energy Technology Data Exchange (ETDEWEB)

    Carlone, Raffaele, E-mail: raffaele.carlone@unina.it [Università “Federico II” di Napoli, Dipartimento di Matematica e Applicazioni “R. Caccioppoli”, MSA, via Cinthia, I-80126, Napoli (Italy); Posilicano, Andrea, E-mail: andrea.posilicano@uninsubria.it [DiSAT, Università dell' Insubria, via Valleggio 11, I-22100, Como (Italy)

    2017-03-26

    We study the spectrum, resonances and scattering matrix of a quantum Hamiltonian on a “hybrid surface” consisting of a half-line attached by its endpoint to the vertex of a concave planar wedge. At the boundary of the wedge, outside the vertex, homogeneous Dirichlet conditions are imposed. The system is tunable by varying the measure of the angle at the vertex. - Highlights: • Spectral characterization of a quantum Hamiltonian on “hybrid surface” consisting of a halfline attached to the vertex of a concave planar wedge. • The system is tunable by varying the measure of the angle at the vertex. • Relation between the conduction properties inside the hybrid and formation of resonances. • Easy generalization of the results to more complicated structures.

  9. The synthesis and adsorption properties of some carbohydrate-terminated dendrimer wedges

    CERN Document Server

    Ainsworth, R L

    1997-01-01

    A range of dendritic molecules that are designed to bind to a cotton surface has been synthesised. The architecture of the molecules allows the location of various functional, property modifying units at the focus and the attachment of recognition groups at the periphery of a dendritic molecule with wedge topology. The synthesis and characterisation of dendrimer wedges up to the second generation using a divergent approach has been performed. These wedges are readily built up using a simple and efficient stepwise pathway from the central core, and surface recognising species are subsequently attached to the molecule utilising procedures developed in conjunction with Unilever Research Laboratories. Work has been carried out to assess their adsorption onto a cotton surface and the postulated adsorption mechanism is discussed.

  10. [Teeth wedge-shaped defects in adults of different age groups: remark to prevention and treatment].

    Science.gov (United States)

    Iordanishvili, A K; Pikhur, O L; Cherni, D A

    The aim of the study was to assess the treatment of teeth wedge defects in different age groups. Records of 383 patients (125 males and 258 females aged 22-85 years) treated in outpatient dental facilities with different ownership forms. It is shown that the medical care of patients with wedge-shaped teeth defects routinely consists of remineralization therapy and restoration of anatomical teeth shape regardless of the form of ownership. The extensiveness of dental rehabilitation as well as the use of more modern technologies are typical for private clinics and 96-100% of patients finished their treatment there. In the state and departmental institutions complete rehabilitation of wedge-shaped defects was provided in 45.5-58.0% and 54.3-83.9, respectively. The paper also highlights the drawbacks of primary medical documentation identified in medical institutions of all forms of ownership.

  11. Is kyphoplasty better than vertebroplasty at restoring form and function after severe vertebral wedge fractures?

    Science.gov (United States)

    Landham, Priyan R; Baker-Rand, Holly L A; Gilbert, Samuel J; Pollintine, Phillip; Annesley-Williams, Deborah J; Adams, Michael A; Dolan, Patricia

    2015-04-01

    The vertebral augmentation procedures, vertebroplasty and kyphoplasty, can relieve pain and facilitate mobilization of patients with osteoporotic vertebral fractures. Kyphoplasty also aims to restore vertebral body height before cement injection and so may be advantageous for more severe fractures. The purpose of this study was to compare the ability of vertebroplasty and kyphoplasty to restore vertebral height, shape, and mechanical function after severe vertebral wedge fractures. This is a biomechanical and radiographic study using human cadaveric spines. Seventeen pairs of thoracolumbar "motion segments" from cadavers aged 70-98 years were injured, in a two-stage process involving flexion and compression, to create severe anterior wedge fractures. One of each pair underwent vertebroplasty and the other kyphoplasty. Specimens were then compressed at 1 kN for 1 hour to allow consolidation. Radiographs were taken before and after injury, after treatment, and after consolidation. At these same time points, motion segment compressive stiffness was assessed, and intervertebral disc "stress profiles" were obtained to characterize the distribution of compressive stress on the vertebral body and neural arch. On average, injury reduced anterior vertebral body height by 34%, increased its anterior wedge angle from 5.0° to 11.4°, reduced intradiscal (nucleus) pressure and motion segment stiffness by 96% and 44%, respectively, and increased neural arch load bearing by 57%. Kyphoplasty caused 97% of the anterior height loss to be regained immediately, although this reduced to 79% after consolidation. Equivalent gains after vertebroplasty were significantly lower: 59% and 47%, respectively (pKyphoplasty reduced vertebral wedging more than vertebroplasty (pkyphoplasty and vertebroplasty. After severe vertebral wedge fractures, vertebroplasty and kyphoplasty were equally effective in restoring mechanical function. However, kyphoplasty was better able to restore vertebral

  12. Combining valgus knee brace and lateral foot wedges reduces external forces and moments in osteoarthritis patients.

    Science.gov (United States)

    Jafarnezhadgero, Amir Ali; Oliveira, Anderson S; Mousavi, Seyed Hamed; Madadi-Shad, Morteza

    2018-01-01

    Osteoarthritis progression can be related to the external knee adduction and flexion moments during walking. Lateral foot wedges and knee braces have been used as treatment for osteoarthritis, but little is known about their influence on knee joint moments generated in the sagittal and frontal planes. Therefore, the aim of the present study was determine the effects of the isolated and combined use of valgus knee brace and lateral wedge foot orthotic on peak forces and moments during gait in knee osteoarthritis patients. Twenty four males (age: 62.1±2.0years) with varus alignment, symptomatic medial compartment knee osteoarthritis participated in this study. Subjects walked over ground at preferred speed in four conditions: (1) no assistive device (control); (2) using lateral wedges, (3) using knee braces, and (4) using both lateral wedges and knee braces. Ground reaction forces (GRF) and moments, as well as lower limb kinematics were recorded. Peak GRF, vertical loading rate, free moment, external knee adduction and flexion moments were compared across conditions. The concurrent use of lateral wedge and knee brace reduced the first peak GRF in the vertical (6%, p=0.002), anterior-posterior (30%, p=0.028) and medial-lateral directions (44%, p=0.029). Moreover, the use of these devices reduced the peak external knee adduction moment (25%, p=0.019), but not the external flexion moment and free moment (p>0.05). The combined use of lateral wedges and knee braces can reduce medial-lateral knee joint loading, but despite reduced peak forces in the sagittal plane, these device do not reduce joint moments. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. The importance of mantle wedge heterogeneity to subduction zone magmatism and the origin of EM1

    Science.gov (United States)

    Turner, Stephen J.; Langmuir, Charles H.; Dungan, Michael A.; Escrig, Stephane

    2017-08-01

    The composition of the convecting asthenospheric mantle that feeds the mantle wedge can be investigated via rear-arc lavas that have minimal slab influence. This "ambient mantle wedge" composition (the composition of the wedge prior to the addition of a slab component) varies substantially both worldwide and within individual arcs. 143Nd/144Nd measurements of rear-arc samples that have minimal slab influence are similar to 143Nd/144Nd in the stratovolcanoes of the adjacent volcanic fronts, suggesting that 143Nd/144Nd of arc-front volcanics are largely inherited from the ambient mantle composition. 143Nd/144Nd correlates with ratios such as Th/U, Zr/Nb, and La/Sm, indicating that these ratios also are strongly influenced by ambient wedge heterogeneity. The same phenomenon is observed among individual volcanoes from the Chilean Southern Volcanic Zone (SVZ), where along-strike variability of the volcanic front tracks that of rear-arc monogenetic volcanics. Depleted mantle wedges are more strongly influenced by slab-derived components than are enriched wedges. This leads to surprising trace element correlations in the global dataset, such as between Pb/Nb and Zr/Nb, which are not explicable by variable compositions or fluxes of slab components. Depleted ambient mantle is present beneath arcs with back-arc spreading; relatively enriched mantle is present adjacent to continents. Ambient mantle wedge heterogeneity both globally and regionally forms isotope mixing trajectories for Sr, Nd and Hf between depleted mantle and EM1-type enriched compositions as represented by Gough Island basalts. Making use of this relationship permits a quantitative match with the SVZ data. It has been suggested that EM1-type mantle reservoirs are the result of recycled lower continental crust, though such models do not account for certain trace element ratios such as Ce/Pb and Nb/U or the surprisingly homogeneous trace element compositions of EM1 volcanics. A model in which the EM1 end

  14. Wedge-shaped parenchymal enhancement peripheral to the hepatic hemangioma : two-phase spiral CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyoung Won; Kim, Tae Kyoung; Han, Joon Koo [College of Medicine and The Institute of Radiation Medicine, Seoul National University, Seoul (Korea, Republic of); Kim, Ah Young; Lee, Hyun Ju [Asan Medical Center, University of Ulsan , Asan (Korea, Republic of); Song, Chi Sung; Choi, Byung Ihn [Seoul City Boramae Hospital, Seoul (Korea, Republic of)

    2000-02-01

    To determine the incidence of hepatic hemangiomas associated with wedge-shaped parenchymal enhancements adjacent to the tumors as seen on two-phase spiral CT images obtained during the hepatic arterial phase and to characterize the two-phase spiral CT findings of those hemangiomas. One hundred and eight consecutive hepatic hemangiomas in 63 patients who underwent two-phase spiral CT scanning during an 11-month period were included in this study. Two-phase spiral CT scans were obtained during the hepatic arterial phase (30-second delay) and portal venous phase (65-second delay) after injection of 120 mL of contrast material at a rate of 3 mL/sec. We evaluated the frequency with which wedge-shaped parenchymal enhancement was adjacent to the hemangiomas during the hepatic arterial phase and divided hemangiomas into two groups according to whether or not wedge-shaped parenchymal enhancement was noted (Group A and Group B). The presence of such enhancement in hemangiomas was correlated with tumor size and the grade of intratumoral enhancement. In 24 of 108 hemangiomas, wedge-shaped parenchymal enhancement adjacent to hepatic tumors was seen on two-phase CT images obtained during the hepatic arterial phase. Mean hemangioma size was 22mm in group A and 24mm in group B. There was no statistically significant relationship between lesion size and the presence of wedge-shaped parenchymal enhancement adjacent to a hemangioma. In 91.7% and 100% of tumors in Group A, and in 9.6% and 17.8% in Group B, hemangiomas showed more than 50% intratumoral enhancement during the arterial and portal venous phase, respectively. Wedge-shaped parenchymal enhancements peripheral to hepatic hemangiomas was more frequently found in tumors showing more than 50% intratumoral enhancement during these two phases (p less than 0.01). Wedge-shaped parenchymal enhancements is not uncommonly seen adjacent to hepatic hemangiomas on two-phase spiral CT images obtained during the hepatic arterial phase. A

  15. Developing a numerical model of ice wedge degradation and trough formation

    Science.gov (United States)

    Garayshin, V.; Nicolsky, D.; Romanovsky, V. E.

    2014-12-01

    The research was initiated as a part of the Next-Generation Ecosystem Experiments (NGEE) in the Arctic and also as a part of the Integrated Ecosystem Model for Alaska. The presented project explores influence of climate (mean annual and summer temperatures, and snow cover depth and density) and physical properties, soil textures and moisture content on thawing and destabilization of ice wedges on the North Slope of Alaska. Recall that ice wedges formed many years ago, when ground cracked and the cracks were filled by water. The infiltrated water then became frozen and turned into ice. When the annual and summer air temperatures become higher, the depth of the active layer increases. Deeper seasonal thawing may cause melting of the ice wedges from their tops. Consequently, the ground starts to settle and a trough form above the ice wedge. Once the trough is formed, the winter snow cover becomes deeper above it and provides a potential feedback mechanism to the further degradation of permafrost. The work deals with analysis of temperature regimes and moisture distribution and dynamics during seasonal cycles of freezing and thawing. The research focuses on the development of a computational approach to the study of seasonal temperature dynamics of the active layer, ice wedge and surrounding it permafrost. A thermo-mechanical model of the ice wedge based on principles of macroscopic thermodynamics and continuum mechanics is presented. The model includes the energy and mass conservation equations, a visco-poroelastic rheology for ground deformation, and an empirical formula which relates unfrozen water content to temperature. The complete system is reduced to a computationally convenient set of coupled equations for the temperature, pore water pressure, ground velocities and porosity in a two-dimensional domain. A finite element method and an implicit scheme in time were utilized to construct a non-linear system of equations, which was solved iteratively. The model

  16. Three-dimensional vertebral wedging and pelvic asymmetries in the early stages of adolescent idiopathic scoliosis.

    Science.gov (United States)

    Begon, Mickaël; Scherrer, Sophie-Anne; Coillard, Christine; Rivard, Charles-Hilaire; Allard, Paul

    2015-03-01

    Scoliosis is a three-dimensional (3D) deformation of the spine and the pelvis. Although the relation between the pelvic asymmetries and scoliosis progression was proposed by several authors, it has not been documented over time in adolescent idiopathic scoliosis (AIS). The objective was to determine whether vertebral wedging and pelvic asymmetries progress in the early stages of AIS before any orthopedic treatment. The study design included an observational cohort study. Nineteen AIS girls participated in this study. The outcome measures were pelvic and spine geometries from simultaneous biplanar radiographs. At the diagnosis, the girls (12.6±1.3 years) had a Cobb angle of 13.9°±6.0°. At the end of their observation period (11 months on average), the scoliosis progressed to 20.5°±5.5°. Bone 3D geometry was reconstructed from biplanar radiographs. Sagittal and frontal wedgings were calculated for five vertebral levels, namely, at the apex and at the two vertebral bodies above and below it. The pelvic geometry was described using five 3D homologous right-left lengths to estimate pelvic asymmetries. Paired t tests were performed on vertebral wedging and pelvic asymmetries to assess their progression between the two evaluations. Principal component (PC) analyses were applied to determine whether vertebral wedging or pelvic asymmetries were predominant at each evaluation. Vertebral wedging was present at the diagnosis (1.76°-5.92°) and generally did not progress until brace prescription. The mean difference between the right and left pelvic normalized lengths was 1.4% and 2.4% for the initial and final evaluations, respectively. Results revealed the width of the right pelvis to be superior by 3%, and this asymmetry progressed to 4.0%. Principal component analysis revealed that initial vertebral wedging was present in seven out of eight parameters of the first three PCs, whereas at the final examination, vertebral wedging and pelvic asymmetries were evenly

  17. Comparison of infinite and wedge fringe settings in Mach Zehnder interferometer for temperature field measurement

    Energy Technology Data Exchange (ETDEWEB)

    Haridas, Divya [Department of Physics, National Institute of Technology Calicut, Kerala, 673601 (India); P, Vibin Antony; Sajith, V.; Sobhan, C. B. [School of Nano Science and Technology, National Institute of Technology Calicut, Kerala, 673601 (India)

    2014-10-15

    Interferometric method, which utilizes the interference of coherent light beams, is used to determine the temperature distribution in the vicinity of a vertical heater plate. The optical components are arranged so as to obtain wedge fringe and infinite fringe patterns and isotherms obtained in each case were compared. In wedge fringe setting, image processing techniques has been used for obtaining isotherms by digital subtraction of initial parallel fringe pattern from deformed fringe pattern. The experimental results obtained are compared with theoretical correlations. The merits and demerits of the fringe analysis techniques are discussed on the basis of the experimental results.

  18. Developing a numerical model of ice wedge degradation and trough formation

    Science.gov (United States)

    Garayshin, V.; Nicolsky, D.; Romanovsky, V. E.

    2016-12-01

    The research was initiated as a part of the Next-Generation Ecosystem Experiments (NGEE) in the Arctic and also as a part of the Integrated Ecosystem Model for Alaska. The presented project explores influence of climate (mean annual and summer temperatures, snow cover depth and physical properties), and soil textures and moisture content on thawing and destabilization of ice wedges on the North Slope of Alaska using numerical modeling. The ice wedges on the North Slope of Alaska have being forming for many millennia, when ground cracked and the cracks were filled with snowmelt water. The infiltrated water then became frozen and turned into ice. When the annual and summer air temperatures become higher, the depth of the active layer increases. Deeper seasonal thawing may cause melting of the ice wedges from their tops. Consequently, the ground starts to settle and a trough form above the ice wedge. Once the trough is formed, the winter snow cover becomes deeper above it and provides a potential positive feedback mechanism to the further degradation of permafrost. The presented work deals with analysis of temperature regimes and dynamics during seasonal cycles of freezing and thawing. The research focuses on the development of a computational approach to the study of seasonal temperature dynamics of the active layer, ice wedge and surrounding it permafrost. A thermo-mechanical model of the ice wedge based on principles of macroscopic thermodynamics and continuum mechanics was developed and will be presented. The model includes the energy and mass conservation equations, a visco-elastic rheology for ground deformation, and an empirical formula which relates unfrozen water content to temperature. The complete system is reduced to a computationally convenient set of coupled equations for the temperature, ground displacements and porosity in a two-dimensional domain. A finite element method and an implicit scheme in time were utilized to construct a non-linear system of

  19. Correction of moderate to severe hallux valgus with combined proximal opening wedge and distal chevron osteotomies: a reliable technique.

    Science.gov (United States)

    Jeyaseelan, L; Chandrashekar, S; Mulligan, A; Bosman, H A; Watson, A J S

    2016-09-01

    The mainstay of surgical correction of hallux valgus is first metatarsal osteotomy, either proximally or distally. We present a technique of combining a distal chevron osteotomy with a proximal opening wedge osteotomy, for the correction of moderate to severe hallux valgus. We reviewed 45 patients (49 feet) who had undergone double osteotomy. Outcome was assessed using the American Orthopaedic Foot and Ankle Society (AOFAS) and the Short Form (SF) -36 Health Survey scores. Radiological measurements were undertaken to assess the correction. The mean age of the patients was 60.8 years (44.2 to 75.3). The mean follow-up was 35.4 months (24 to 51). The mean AOFAS score improved from 54.7 to 92.3 (p technique which, when compared with other metatarsal osteotomies, provides strong angular correction and excellent outcomes with a low rate of complications. Cite this article: Bone Joint J 2016;98-B:1202-7. ©2016 The British Editorial Society of Bone & Joint Surgery.

  20. Determination of refractive index of a simple negative, positive, or zero power lens using wedged plated interferometer

    Science.gov (United States)

    Shukla, R. P.; Perera, G. M.; George, M. C.; Venkateswarlu, P.

    1990-01-01

    A nondestructive technique for measuring the refractive index of a negative lens using a wedged plate interferometer is described. The method can be also used for measuring the refractive index of convex or zero power lenses. Schematic diagrams are presented for the use of a wedged plate interferometer for measuring the refractive index of a concave lens and of a convex lens.

  1. Evaluation of off-axis wedge correction factor using diode dosimeters for estimation of delivered dose in external radiotherapy

    Directory of Open Access Journals (Sweden)

    Mahmoud Allahverdi

    2012-01-01

    Full Text Available An in vivo dosimetry system, using p-type diode dosimeters, was characterized for clinical applications of treatment machines ranging in megavoltage energies. This paper investigates two different models of diodes for externally wedged beams and explains a new algorithm for the calculation of the target dose at various tissue depths in external radiotherapy. The values of off-axis wedge correction factors were determined at two different positions in the wedged (toward the thick and thin edges and in the non-wedged directions on entrance and exit surfaces of a polystyrene phantom in 60 Co and 6 MV photon beams. Depth transmission was defined on the entrance and exit surfaces to obtain the off-axis wedge correction factor at any depth. As the sensitivity of the diodes depends on physical characteristics [field size, source-skin distance (SSD, thickness, backscatter], correction factors were applied to the diode reading when measuring conditions different from calibration situations . The results indicate that needful correction factors for 60 Co wedged photons are usually larger than those for 6 MV wedged photon beams. In vivo dosimetry performed with the proposed algorithms at externally wedged beams has negligible probable errors (less than 0.5% and is a reliable method for patient dose control.

  2. Commissioning Siemens Virtual Wedges in the Oncentra MasterPlan treatment planning system using Gafchromic EBT film.

    Science.gov (United States)

    Ferretti, A; Simonato, F; Zandonà, R; Reccanello, S; Fabbris, R

    2010-12-01

    Virtual Wedges were introduced in Siemens LINACs to improve the treatment workflow. The aim of the present work is the validation of dose calculation by MasterPlan-Oncentra treatment planning system for virtual wedged beams. The Oncor Siemens accelerator installed in the authors' department produces 6 and 15 MV photon beams. At first, the consistency of VW LINAC production was tested and the EBT film measuring method was verified. This method is based on the scanner uniformity correction and absolute dose calibration as reported in literature. Then, the measured and calculated wedge factors and beam profiles are compared. For 15 degrees, 30 degrees, 45 degrees, and 60 degrees wedge angles, the wedge factors for different field sizes were measured by an ionization chamber and the dose profiles were acquired by Gafchromic EBT film. Both types of measurements were collected in isocentric condition. The comparison between measured and calculated VW factors shows discrepancies that increase with field size and angle. The OTP Enhanced algorithm produces better agreement with measurements than the Classic one, with improvement overall visible for large angles. The agreement between measured and planned beam profiles is within limits reported by the ESTRO Booklet No. 7 in terms of confidence limits. The MasterPlan-Oncentra treatment planning system determines wedge factors and VW profiles within the requested accuracy in the majority of treatment conditions. For big field dimensions and wedge angle, wedge factor accordance was worse, but it may be increased with an improvement of the LINAC dosimetric board calibration.

  3. A new GTD slope diffraction coefficient for plane wave illumination of a wedge

    DEFF Research Database (Denmark)

    Lumholt, Michael; Breinbjerg, Olav

    1997-01-01

    Two wedge problems including slope diffraction are solved: one in which the incident field is a non-uniform plane wave, and one in which it is an inhomogeneous plane wave. The two solutions lead to the same GTD slope diffraction coefficient. This coefficient reveals the existence of a coupling...

  4. A Novel Continuous Extrusion Process to Fabricate Wedge-Shaped Light Guide Plates

    Directory of Open Access Journals (Sweden)

    Wen-Tse Hsiao

    2013-01-01

    Full Text Available Backlight modules are key components in thin-film transistor liquid crystal displays (TFT-LCD. Among the components of a backlight module, the light guide plate (LGP plays the most important role controlling the light projected to the eyes of users. A wedge-shaped LGP, with its asymmetrical structure, is usually fabricated by an injection proces, but the fabrication time of this process is long. This study proposes a continuous extrusion process to fabricate wedge-shaped LGPs. This continuous process has advantages for mass production. Besides a T-die and rollers, this system also has an in situ monitor of the melt-bank that forms during the extrusion process, helping control the plate thickness. Results show that the melt bank has a close relationship with the plate thickness. The temperature of the bottom heater and roller was adjusted to reduce the surface deformation of the wedge-shaped plate. This continuous extrusion system can successfully manufacture wedge-shaped LGPs for mass production.

  5. Non-invasive assessment of pulmonary capillary wedge pressure in the elderly by the Valsalva manoeuvre

    NARCIS (Netherlands)

    Remmen, Johannes Jacobus

    2006-01-01

    Heart failure (HF) is primarily a disorder of the elderly. However, in the elderly, physical examination and radiographic methods are not accurate in the diagnosis of HF. Pulmonary capillary wedge pressure (PCWP) provides an estimate of cardiac filling pressure and can be used to diagnose HF.

  6. Interaction of light with a metal wedge: the role of diffraction in shaping energy flow.

    Science.gov (United States)

    Xi, Yonggang; Jung, Yun Suk; Kim, Hong Koo

    2010-02-01

    When a light wave hits a metal wedge structure, the metal surfaces respond to the incident light by generating both free-space and surface-bound waves. Here we present a physical model that elucidates electromagnetic interactions of an incoming planar wave with a simple semi-infinite 90 degrees metal wedge. We show that a metal wedge structure possesses an intrinsic capability of directing the incident power around the corner into the forward direction. Interplay of the boundary diffraction wave and the incident and reflection waves in the near field region of a metal corner is found to form a basis of the funneling phenomena that are commonly observed in metal nanoslit structures. Theory and experiment reveal that the incident wave propagating parallel to the sidewall destructively interferes with the boundary diffraction wave forming a depleted-energy-flow region along the glancing angle direction. A physical understanding of various electromagnetic phenomena associated with a metal wedge structure confirms rich potential of the simple structure as an elemental building block of complex metal nanostructures.

  7. NOTE: Dosimetric characteristics of dynamic wedged fields: a Monte Carlo study

    Science.gov (United States)

    Shih, Rompin; Li, X. Allen; Hsu, Wen-Lin

    2001-12-01

    We have developed a Monte Carlo (MC) technique using the EGS4/BEAM system to calculate dosimetric characteristics of dynamic wedges (DW) for photon beam radiotherapy. The simulation of DW was accomplished by weighting the history numbers of the electrons, which are incident on the target in accordance with the segmented treatment table. Calculations were performed for DW with wedge angles ranging from 15° to 60° as well as for open fields with different field sizes for both 6 and 18 MV beams. The MC-calculated percentage depth dose (PDD) and beam profiles agreed with the measurements within +/-2% (of the dose maximum along the beam axis) or +/-2 mm in high dose gradient region. The DW slightly affects energy spectra of photons and contaminating electrons. These slight changes have no significant effects on PDD as compared to the open field. The MC-calculated dynamic wedge factors agree with the measurements within +/-2%. The MC method enables us to provide more detailed beam characteristics for DW fields than a measurement method. This beam characteristic includes photon energy spectra, mean energy, spectra of contaminating electrons and effects of moving jaw on off-axis beam quality. These data are potentially important for treatment planning involving dynamic wedges.

  8. Application of Orthopedic Dual Sliding Compression Plate (ODSCP) in High Medial Tibial Open Wedge Osteotomies.

    Science.gov (United States)

    Samani, Seyed Salman; Kachooei, Amir Reza; Ebrahimzadeh, Mohammad Hosein; Omidi Kashani, Farzad; Mahdavian Naghashzargar, Reza; Razi, Shiva

    2013-04-01

    Angular deformities about the knee are one of the common disorders. High Tibial osteotomy is a way of correcting the deformity. Although the general agreement is focused toward the open wedge technique, discussion about the type of device is a subject to debate. This current study has attempted to evaluate the results of Orthopedic Dual Sliding Compression Plate (ODSCP) in high medial open wedge osteotomies of the tibia. In this cross-sectional study, 16 patients with genuvarum undergone high medial tibial open wedge osteotomy and fixed by Orthopedic Dual Sliding Compression Plate. At the time of the last follow up visit, Lysholm score was gathered. The mean follow-up time was 9.33 ± 1.87 month. The average age was 45.13 ± 7.25 years. Three patients were male and 13 patients were female. The lysholm score showed a significant difference before and after surgery. The ODSCP has many advantages over the other type of plates. It can help the surgeon to operate with a relaxed mind and it is advisable for high tibial medial open wedge osteotomies.

  9. In situ spatiotemporal measurements of the detailed azimuthal substructure of the substorm current wedge

    DEFF Research Database (Denmark)

    Forsyth, C.; Fazakerley, A. N.; Rae, I. J.

    2014-01-01

    The substorm current wedge (SCW) is a fundamental component of geomagnetic substorms. Models tend to describe the SCW as a simple line current flowing into the ionosphere toward dawn and out of the ionosphere toward dusk, linked by a westward electrojet. We use multispacecraft observations from p...

  10. Numerical Simulation and Experimental Validation of an Integrated Sleeve-Wedge Anchorage for CFRP Rods

    DEFF Research Database (Denmark)

    Schmidt, Jacob Wittrup; Smith, Scott T.; Täljsten, Björn

    2011-01-01

    The tensioning of carbon fibre-reinforced polymer (CFRP) rods for prestressed concrete applications or post-tensioning repair and strengthening has met with mixed success. This is primarily due to limitations inherent in the use of traditional wedge anchors typically used for steel tendons...

  11. On the role of lateral waves in the radiation from the dielectric wedge

    DEFF Research Database (Denmark)

    Balling, Peter

    1973-01-01

    The field on the dielectric wedge is approximated by a plane-wave expansion as in [1]. Contributions from this solution to both the surface field and the radiation field are examined. Finally, an experimental radiation field is compared with the plane-wave solution and with a geometric...

  12. Modeling 3-D flow in the mantle wedge with complex slab geometries: Comparisons with seismic anisotropy

    Science.gov (United States)

    Kincaid, C. R.; MacDougall, J. G.; Druken, K. A.; Fischer, K. M.

    2010-12-01

    Understanding patterns in plate scale mantle flow in subduction zones is key to models of thermal structure, dehydration reactions, volatile distributions and magma generation and transport in convergent margins. Different patterns of flow in the mantle wedge can generate distinct signatures in seismological observables. Observed shear wave fast polarization directions in several subduction zones are inconsistent with predictions of simple 2-D wedge corner flow. Geochemical signatures in a number of subduction zones also indicate 3-D flow and entrainment patterns in the wedge. We report on a series of laboratory experiments on subduction driven flow to characterize spatial and temporal variability in 3-D patterns in flow and shear-induced finite strain. Cases focus on how rollback subduction, along-strike dip changes in subducting plates and evolving gaps or tears in subduction zones control temporal-spatial patterns in 3-D wedge flow. Models utilize a glucose working fluid with a temperature dependent viscosity to represent the upper 2000 km of the mantle. Subducting lithosphere is modeled with two rubber-reinforced continuous belts. Belts pass around trench and upper/lower mantle rollers. The deeper rollers can move laterally to allow for time varying dip angle. Each belt has independent speed control and dip adjustment, allowing for along-strike changes in convergence rate and the evolution of slab gaps. Rollback is modeled using a translation system to produce either uniform and asymmetric lateral trench motion. Neutral density finite strain markers are distributed throughout the fluid and used as proxies for tracking the evolution of anisotropy through space and time in the evolving flow fields. Particle image velocimetry methods are also used to track time varying 3-D velocity fields for directly calculating anisotropy patterns. Results show that complex plate motions (rollback, steepening) and morphologies (gaps) in convergent margins produce flows with

  13. Cumulative effects of climate change and ice-wedge degradation, Prudhoe Bay oilfield Alaska

    Science.gov (United States)

    Walker, D. A.; Kanevskiy, M. Z.; Shur, Y.; Raynolds, M. K.; Buchhorn, M.

    2016-12-01

    Development of Arctic oil & gas resources requires extensive networks of roads, pipelines and other forms of infrastructure. The Prudhoe Bay Oilfield is the largest Arctic oilfield in North America with a long, well-documented history. In a previous publication we analyzed the historical record of high-resolution aerial photos to document the long-term changes to infrastructure extent (1949-2010) for the entire oilfield, and an integrated-geoecological-historical-change-mapping (IGHCM) approach to document terrain changes within 22-km2 areas of the oilfield. We reported the recent widespread expansion of thermokarst, starting in about 1989. Here we examine the annual air-photo record to better pinpoint the years of major change. We also conducted detailed field studies of roadside changes using topographic surveys and soil, vegetation and ice-wedge coring studies. Both sites exhibit extensive ice-wedge degradation that is caused by a combination of a long-term warming trend a series of exceptionally warm summers, and infrastructure-related factors that melted the tops of ice wedges. Near-road thermokarst is enhanced by warmer soils associated with road dust, roadside flooding, near-road pipelines, communication cables, and altered snow regimes. These strongly affect roadside ecosystems and the infrastructure itself. Changes to ecosystems include altered hydrology with the drying of polygon centers and the formation of well-developed high-centered polygons occurs in some areas. Other areas develop extensive flooding and erosion of ice-wedge troughs. An unexpected result of flooding is the stabilization of ice-wedge degradation in some areas because the increased productivity of sedges in the flooded areas is producing large amounts of organic material that protects the tops of ice wedges from further degradation. The large increases in productivity in roadside areas also attract large flocks of waterfowl. Changes to the soils with the addition of thick layers of

  14. Simulation of Climate Control On Tectonic Mass-transfer In Bivergent Orogenic Wedges ­ Insights From Scaled Sandbox Models.

    Science.gov (United States)

    Hoth, S.; Adam, J.; Kukowski, N.; Oncken, O.

    Orogenic wedges are expressions of dynamic equilibrium between tectonic and grav- itational stresses. Thus, surficial mass transport by climate-driven erosion changes the morphology of, and the state of stress within, the orogenic wedge. Here, we suggest that the orogenic wedge adjusts itself to the new stress conditions, inducing changes in morphology, which may modify the pre-existing drainage pattern, and therefore change also the erosion rate. Depending on the amount of vertical alteration in wedge morphology the regional climate is modified, which again may lead to a different ero- sion rate. The aim of this study is to describe qualitatively and quantitatively how different ero- sion rates and their 2D lateral distribution influences the mass-transport mode in col- lisional orogens, using scaled sandbox-experiments. The advantages of analogue sim- ulation are (i) a more detailed structural resolution, (ii) a direct observation of strain localisation and fault propagation and (iii) an easy way of applying erosion at any given point through time. The models presented here were run in a 2D shearbox with two converging sand lay- ers which build up a bivergent sand-orogen. A thin glass-bead layer which simulates a mid-level detachment was incorporated to allow frontal and basal accretion. Us- ing a vacuum cleaner, incremental erosion, which decreases linearly from the top of the sand-orogen to the toe of either the pro-wedge or retro-wedge, was simulated. A friction-controlled elastic/plastic rheology with strain hardening and softening is used to simulate upper crustal rock deformation. Our aim is to elucidate: (i) The in- fluence of different modes of distribution of erosion rates on the tectonically-driven mass transfer in orogenic belts. (ii) The control of erosion rates on tectonic style in orogenic wedges, i.e. frontal versus basal accretion. (iii) The time and length scales at which climatic and tectonic forces interact. (iv) The way with which such

  15. The Effect of the Vertex Angles of Wedged Indenters on Deformation during Nanoindentation

    Directory of Open Access Journals (Sweden)

    Xiaowen Hu

    2017-12-01

    Full Text Available In order to study the effect of the angle of wedged indenters during nanoindentation, indenters with half vertex angles of 60°, 70° and 80° are used for the simulations of nanoindentation on FCC aluminum (Al bulk material by the multiscale quasicontinuum method (QC. The load-displacement responses, the strain energy-displacement responses, and hardness of Al bulk material are obtained. Besides, atomic configurations for each loading situation are presented. We analyze the drop points in the load-displacement responses, which correspond to the changes of microstructure in the bulk material. From the atom images, the generation of partial dislocations as well as the nucleation and the emission of perfect dislocations have been observed with wedged indenters of half vertex angles of 60° and 70°, but not 80°. The stacking faults move beneath the indenter along the direction [ 1 1 ¯ 0 ] . The microstructures of residual displacements are also discussed. In addition, hardness of the Al bulk material is different in simulations with wedged indenters of half vertex angles of 60° and 70°, and critical hardness in the simulation with the 70° indenter is bigger than that with the 60° indenter. The size effect of hardness in plastic wedged nanoindentation is observed. There are fewer abrupt drops in the strain energy-displacement response than in the load-displacement response, and the abrupt drops in strain energy-displacement response reflect the nucleation of perfect dislocations or extended dislocations rather than partial dislocations. The wedged indenter with half vertex angle of 70° is recommended for investigating dislocations during nanoindentation.

  16. Role of ground ice dynamics and ecological feedbacks in recent ice wedge degradation and stabilization

    Science.gov (United States)

    Mark Torre Jorgenson,; Mikhail Kanevskiy,; Yuri Shur,; Natalia Moskalenko,; Dana Brown,; Wickland, Kimberly P.; Striegl, Robert G.; Koch, Joshua C.

    2015-01-01

    Ground ice is abundant in the upper permafrost throughout the Arctic and fundamentally affects terrain responses to climate warming. Ice wedges, which form near the surface and are the dominant type of massive ice in the Arctic, are particularly vulnerable to warming. Yet processes controlling ice wedge degradation and stabilization are poorly understood. Here we quantified ice wedge volume and degradation rates, compared ground ice characteristics and thermal regimes across a sequence of five degradation and stabilization stages and evaluated biophysical feedbacks controlling permafrost stability near Prudhoe Bay, Alaska. Mean ice wedge volume in the top 3 m of permafrost was 21%. Imagery from 1949 to 2012 showed thermokarst extent (area of water-filled troughs) was relatively small from 1949 (0.9%) to 1988 (1.5%), abruptly increased by 2004 (6.3%) and increased slightly by 2012 (7.5%). Mean annual surface temperatures varied by 4.9°C among degradation and stabilization stages and by 9.9°C from polygon center to deep lake bottom. Mean thicknesses of the active layer, ice-poor transient layer, ice-rich intermediate layer, thermokarst cave ice, and wedge ice varied substantially among stages. In early stages, thaw settlement caused water to impound in thermokarst troughs, creating positive feedbacks that increased net radiation, soil heat flux, and soil temperatures. Plant growth and organic matter accumulation in the degraded troughs provided negative feedbacks that allowed ground ice to aggrade and heave the surface, thus reducing surface water depth and soil temperatures in later stages. The ground ice dynamics and ecological feedbacks greatly complicate efforts to assess permafrost responses to climate change.

  17. Structure of the Orogenic Wedge in the Bhutan Himalaya: First Results from the GANSSER Seismic Experiment

    Science.gov (United States)

    Singer, J.; Hetényi, G.; Diehl, T.; Kissling, E. H.

    2014-12-01

    In the Eastern Himalaya, the structure of the orogenic wedge above the subducting Indian lithosphere and even the Moho topography of the latter are poorly constrained at present. The Main Himalayan Thrust (MHT) is considered a crustal-scale detachment that marks the plate boundary separating the bottom of the orogenic wedge from the top of the Indian crust. In western and central Himalaya portions of the MHT have been imaged by receiver functions (RF) from the surface near the foothills of the Himalayan front range to mid-crustal depths. In Bhutan, however, the MHT and other major thrust geometries at depth remain a matter of debate, without direct geophysical image. Furthermore, earthquake activity in Bhutan seems to be significantly lower compared to most other parts of the Himalayan arc and there appears to be a lack of great earthquakes. This lower level of seismicity could be related to a more ductile deformation in the orogenic wedge, or, alternatively, result from a currently locked situation of the thrust system. In this work, we use data of a densely spaced, temporary seismic network in Bhutan (GANSSER experiment) to determine lithospheric and intra-crustal discontinuities in the Eastern Himalaya with RF complemented by seismic velocities derived from simultaneous inversion of local earthquake data. Along two south-north profiles across the Himalayan range in eastern and western Bhutan the geometry of the dipping Indian Moho is defined by migrated RF images including a dip correction. Based on the characteristics of the RF, the dip and strike of the Moho is independently defined and the occurrence of intra-crustal conversion interfaces like the MHT are mapped across the orogenic wedge. In combination with the geometry of the intra-crustal seismic structure, we use the seismic velocities and the hypocenters of local earthquakes to discuss the predominant deformation type in the orogenic wedge in Bhutan and the potential for large earthquakes in this region

  18. Differences in wedge factor determination in air using a PMMA mini-phantom or a brass build-up cap.

    Science.gov (United States)

    Heukelom, S; Lanson, J H; Mijnheer, B J

    1997-12-01

    The head scatter dose contribution to the output of a treatment machine has been determined for an open and wedged 60Co gamma-ray beam and for open and wedged x-ray beams of 4, 8, and 16 MV. From those data wedge factor values "in air" have been deduced, expressed as the ratio of the dose to water, measured in air, for the situation with and without wedge, for the same number of monitor units (or treatment time for 60Co). The measurements have been performed using a polymethyl-metacrylate (PMMA) and a graphite-walled ionization chamber inserted in a brass build-up cap and in a PMMA mini-phantom, respectively. Absolute wedge factor values deduced with both detector systems and based on the ratio of ionization chamber readings, differ for the investigated photon beams, up to 3.5% for the 4 MV x-ray beam. The deviations results from the difference in composition between the detector materials and water and can be taken into account by conversion of the ionization chamber readings for both the open and wedged photon beams to the absorbed dose to water. For the brass build-up cap detector system the ratio of the conversion factors for the wedged and open beam changes the ratio of the ionization chamber readings up to about 3.6% for the 4 MV x-ray beam. For the mini-phantom the conversion factors for the wedged and open beam are almost equal for all photon beams. Consequently, for that system wedge factors based on ionization chamber readings or dose values are the same. With respect to the wedge factor variation with field size a somewhat larger increase has been determined for the 60Co and 4 MV photon beam using the brass build-up cap: about 1% for field sizes varying between 5 cm x 5 cm and 15 cm x 15 cm. This effect has to be related to an apparent more pronounced variation of the head scatter dose contribution with field size for the wedged photon beams if the brass build-up cap detection system is used. It can be concluded that determination of wedge factors "in

  19. Standard practice for making and using precracked double beam stress corrosion specimens

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2000-01-01

    1.1 This practice covers procedures for fabricating, preparing, and using precracked double beam stress corrosion test specimens. This specimen configuration was formerly designated the double cantilever beam (DCB) specimen. Guidelines are given for methods of exposure and inspection. 1.2 The precracked double beam specimen, as described in this practice, is applicable for evaluation of a wide variety of metals exposed to corrosive environments. It is particularly suited to evaluation of products having a highly directional grain structure, such as rolled plate, forgings, and extrusions, when stressed in the short transverse direction. 1.3 The precracked double beam specimen may be stressed in constant displacement by bolt or wedge loading or in constant load by use of proof rings or dead weight loading. The precracked double beam specimen is amenable to exposure to aqueous or other liquid solutions by specimen immersion or by periodic dropwise addition of solution to the crack tip, or exposure to the atmos...

  20. Double inflation

    Energy Technology Data Exchange (ETDEWEB)

    Silk, J.; Turner, M.S.

    1986-04-01

    The Zel'dovich spectrum of adiabatic density perturbations is a generic prediction of inflation. There is increasing evidence that when the spectrum is normalized by observational data on small scales, there is not enough power on large scales to account for the observed large-scale structure in the Universe. Decoupling the spectrum on large and small scales could solve this problem. As a means of decoupling the large and small scales we propose double inflation (i.e., two episodes of inflation). In this scenario the spectrum on large scales is determined by the first episode of inflation and those on small scales by a second episode of inflation. We present three models for such a scenario. By nearly saturating the large angular-scale cosmic microwave anisotropy bound, we can easily account for the observed large-scale structure. We take the perturbations on small scales to be very large, deltarho/rho approx. = 0.1 to 0.01, which results in the production of primordial black holes (PBHs), early formation of structure, reionization of the Universe, and a rich array of astrophysical events. The ..cap omega..-problem is also addressed by our scenario. Allowing the density perturbations produced by the second episode of inflation to be large also lessens the fine-tuning required in the scalar potential and makes reheating much easier. We briefly speculate on the possibility that the second episode of inflation proceeds through the nucleation of bubbles, which today manifest themselves as empty bubbles whose surfaces are covered with galaxies. 37 refs., 1 fig.

  1. Seeing Double

    Science.gov (United States)

    Pesic, Peter

    2003-10-01

    The separateness and connection of individuals is perhaps the central question of human life: What, exactly, is my individuality? To what degree is it unique? To what degree can it be shared, and how? To the many philosophical and literary speculations about these topics over time, modern science has added the curious twist of quantum theory, which requires that the elementary particles of which everything consists have no individuality at all. All aspects of chemistry depend on this lack of individuality, as do many branches of physics. From where, then, does our individuality come? In Seeing Double, Peter Pesic invites readers to explore this intriguing set of questions. He draws on literary and historical examples that open the mind (from Homer to Martin Guerre to Kafka), philosophical analyses that have helped to make our thinking and speech more precise, and scientific work that has enabled us to characterize the phenomena of nature. Though he does not try to be all-inclusive, Pesic presents a broad range of ideas, building toward a specific point of view: that the crux of modern quantum theory is its clash with our ordinary concept of individuality. This represents a departure from the usual understanding of quantum theory. Pesic argues that what is bizarre about quantum theory becomes more intelligible as we reconsider what we mean by individuality and identity in ordinary experience. In turn, quantum identity opens a new perspective on us. Peter Pesic is a Tutor and Musician-in-Residence at St. John's College, Santa Fe, New Mexico. He has a Ph.D. in physics from Stanford University.

  2. Estimating effective wedge factor for enhanced dynamic wedge 2100CD a Varian Clinac; Calculo De factor cuna efectiva para cuna dinamica mejorada de un Clinac 2100CD de Varian

    Energy Technology Data Exchange (ETDEWEB)

    Pizarro Trigo, F.; Morillas Ruiz, J.; Nunuz Martinez, L.; Sanchez Jimenez, J.

    2011-07-01

    The purpose of this paper is to compare different methods of calculating the effective factor enhanced dynamic wedge (EDWF) with the values ??obtained in measurements of symmetric and asymmetric fields.

  3. On the Effect of Structural Response on the Hydrodynamic Loading of a Free-Falling Wedge

    Science.gov (United States)

    Ikeda, Christine; Taravella, Brandon; Judge, Carolyn

    2016-11-01

    High-speed planing craft are subjected to repeated slamming events in waves that can be very extreme depending on the wave topography, impact angle of the ship, forward speed of the ship, encounter angle, and height out of the water. The current work examines this fluid-structure interaction problem through the use of wedge drop experiments and a theoretical prediction. The experimental program consisted of two 20° deadrise angle wedges dropped from a range of heights, 0 . 15 theory in order to determine the effects of flexibility on the hydrodynamic pressure. The code assumes a rigid structure, therefore, the results between the code and the first experiment are in good agreement. The second experiment shows pressure magnitudes that are lower than the predictions due to the energy required to deform the structure. This work is funded by the Office of Naval Research and the state of Louisiana Board of Regents Industrial Ties and Reseach Subprogram.

  4. Physical Analysis of Cross-Wedge Rolling Process of a Stepped Shaft

    Directory of Open Access Journals (Sweden)

    Łukasz Wójcik

    2017-12-01

    Full Text Available The paper presents experimental- model research results on the process of cross-wedge rolling of an axially-symmetrical element (stepped shaft. During research was used plastic mass on the basis of waxes in black and white colour. The aim of this experimental research was to determine the best option of forming in terms of values obtained and the course of forces. Physical examination was carried out using specialist machines, that is model and laboratory cross-wedge rolling mill. Experimental analysis was carried out using billets with the temperature of 15°C, whereas the actual process was carried out for billet from C45 carbon steel of temperature 1150°C. The study compared the dimensions of the components obtained during rolling tests and forming forces obtained in the result of physical modeling with forces obtained during real tests.

  5. Experimental constraints on the impact of slab dip, gaps and rollback on mantle wedge flow

    Science.gov (United States)

    MacDougall, J. G.; Szwaja, S.; Kincaid, C. R.; Fischer, K. M.

    2012-12-01

    We conducted fluids experiments to better understand how subduction zone mantle flow and seismic anisotropy relate to slab dip variations, slab gaps, and retrograde trench motion. Subducting lithosphere was modeled with two rubber-reinforced continuous belts that pass around rollers at the trench and at the equivalent of 670 km depth; the advecting mantle was represented by an isoviscous glucose fluid. Each belt had a variable dip and speed, and trench rollback was modeled using translation of the belt system. Neutral density rotation markers ("whiskers") as well as beads and bubbles were used to track flow patterns; whiskers were also used as proxies for finite strain and were assumed to reflect the evolution of olivine fabrics and anisotropy. The dips of the two slab segments were systematically varied from 30° to 80° at subduction rates equivalent to 4 and 8 cm/yr, and in select cases trench rollback equivalent to 3 cm/yr was imposed. Reference cases with identical parameters for the two slab belts produced mantle wedge flow that reflected simple entrainment by the slab, with flow lines that were roughly trench-normal in much of the wedge, except for toroidal flow around the lateral edges of the slab. Dip variations between the slab segments deflected mantle wedge flow lines towards trench-parallel in the direction of the shallower slab, in agreement with prior numerical modeling studies. The degree of along-arc deflection increased as the slab dip difference grew. Deflection also increased as the absolute dip of the shallower-dipping segment decreased, as predicted by analytical estimates of trench-parallel pressure gradients (Hall et al., 2000). Whisker alignments showed the greatest evidence for extension and alignment of olivine a-axes that are sub-parallel to the trench in the mantle wedge close to the change in slab dip, consistent with the numerical models of Kneller and Van Keken (2007). The addition of trench rollback to a given set of experimental

  6. Effects of radiation on convection heat transfer of Cu-water nanofluid past a moving wedge

    Directory of Open Access Journals (Sweden)

    Salama Faiza A.

    2016-01-01

    Full Text Available Heat transfer characteristics of a two-dimensional steady hydrodynamic flow of water-based copper(Cu nanofluid over a moving wedge, taking into account the effects of thermal radiation, have been investigated numerically. The Rosseland approximation is used to describe the radiative heat flux in the energy equation. The governing fundamental equations are first transformed into a system of ordinary differential equations and solved numerically by using the fourth-order Runge-kutta method with shooting technique. A comparison with previously published work has been carried out and the results are found to be in good agreement. The existence of unique and dual solutions for self-similar equations of the flow and heat transfer are analyzed numerically. The results indicate that there is strong dependence of the thermal gradient at the surface of the wedge on both velocity ratio parameter and thermal radiation.

  7. Refinement of the wedge bar technique for compression tests at intermediate strain rates

    Directory of Open Access Journals (Sweden)

    Stander M.

    2012-08-01

    Full Text Available A refined development of the wedge-bar technique [1] for compression tests at intermediate strain rates is presented. The concept uses a wedge mechanism to compress small cylindrical specimens at strain rates in the order of 10s−1 to strains of up to 0.3. Co-linear elastic impact principles are used to accelerate the actuation mechanism from rest to test speed in under 300μs while maintaining near uniform strain rates for up to 30 ms, i.e. the transient phase of the test is less than 1% of the total test duration. In particular, a new load frame, load cell and sliding anvil designs are presented and shown to significantly reduce the noise generated during testing. Typical dynamic test results for a selection of metals and polymers are reported and compared with quasistatic and split Hopkinson pressure bar results.

  8. Uniform physical theory of diffraction equivalent edge currents for truncated wedge strips

    DEFF Research Database (Denmark)

    Johansen, Peter Meincke

    1996-01-01

    New uniform closed-form expressions for physical theory of diffraction equivalent edge currents are derived for truncated incremental wedge strips. In contrast to previously reported expressions, the new expressions are well behaved for all directions of incidence and observation and take a finite...... value for zero strip length. This means that the expressions are well suited for implementation in general computer codes. The new expressions are expressed as the difference between two terms. The first term is obtained by integrating the exact fringe wave current on a wedge along an untruncated...... incremental strip extending from the leading edge of the structure under consideration. The second term is calculated from an integration of the asymptotic fringe wave (FW) current along another untruncated incremental strip extending from the trailing edge of the structure. The new expressions are tested...

  9. Switched reluctance motor with magnetic slot wedges for automotive traction application

    Science.gov (United States)

    Belhadi, M.'Hamed; Krebs, Guillaume; Marchand, Claude; Hannoun, Hala; Mininger, Xavier

    2015-12-01

    The switched reluctance motor (SRM) is very attractive because of its many advantages especially in electric vehicle (EV). However, it presents two major drawbacks: torque ripples and stator vibrations. These phenomena are the cause of a disturbing noise. In order to reduce the torque ripples and the radial force (main cause of the stator vibrations), one solution is to add magnetic slot wedges. In this paper, a SRM with wedges is compared to the conventional one including some static and dynamic features. First, field lines, magnetization curves and static torques are discussed. Secondly, torque-speed curves, harmonic analyzes and cartographies with minimum ripples are compared. The last includes several operating points (speed-torque) in steady state.

  10. INFLUENCE OF MOTOR CAPABILITIES ON EFFICACY IN PERFORMING WEDGE TURNING IN ALPINE SKIING

    Directory of Open Access Journals (Sweden)

    Rašid Hadžić

    2012-09-01

    Full Text Available Goal of this research is to fortify a degree of influence of motor capabilities on efficacy in performing wedge turning in alpine skiing. Research has been conducted on sample of 30 students, average age 22 years, gender-male, 9 motor tests. From derived results come that motor capabilities in showing space have significant influence on successfulness in performing elements of alpine skiing.

  11. 2D Traveling Wave Array Employing a Trapezoidal Dielectric Wedge for Beam Steering

    Science.gov (United States)

    Host, Nicholas K.; Chen, Chi-Chih; Volakis, John L.; Miranada, Felix A.

    2014-01-01

    This presentation addresses the progress made so far in the development of an antenna array with reconfigurable transmission line feeds connecting each element in series. In particular, 2D traveling wave array employing trapezoidal Dielectric Wedge for Beam Steering will be discussed. The presentation includes current status of the effort and suggested future work. The work is being done as part of the NASA Office of the Chief Technologist's Space Technology Research Fellowship (NSTRF).

  12. Deciphering assumptions about stepped wedge designs: the case of Ebola vaccine research.

    Science.gov (United States)

    Doussau, Adélaïde; Grady, Christine

    2016-12-01

    Ethical concerns about randomising persons to a no-treatment arm in the context of Ebola epidemic led to consideration of alternative designs. The stepped wedge (SW) design, in which participants or clusters are randomised to receive an intervention at different time points, gained popularity. Common arguments in favour of using this design are (1) when an intervention is likely to do more good than harm, (2) all participants should receive the experimental intervention at some time point during the study and (3) the design might be preferable for practical reasons. We examine these assumptions when considering Ebola vaccine research. First, based on the claim that a stepped wedge design is indicated when it is likely that the intervention will do more good than harm, we reviewed published and ongoing SW trials to explore previous use of this design to test experimental drugs or vaccines, and found that SW design has never been used for trials of experimental drugs or vaccines. Given that Ebola vaccines were all experimental with no prior efficacy data, the use of a stepped wedge design would have been unprecedented. Second, we show that it is rarely true that all participants receive the intervention in SW studies, but rather, depending on certain design features, all clusters receive the intervention. Third, we explore whether the SW design is appealing for feasibility reasons and point out that there is significant complexity. In the setting of the Ebola epidemic, spatiotemporal variation may have posed problematic challenges to a stepped wedge design for vaccine research. Finally, we propose a set of points to consider for scientific reviewers and ethics committees regarding proposals for SW designs. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  13. Muon Intensity Increase by Wedge Absorbers for Low-E Muon Experiments

    Energy Technology Data Exchange (ETDEWEB)

    Neuffer, D. V. [Fermilab; Stratakis, D. [Fermilab; Bradley, J. [Fermilab

    2017-09-01

    Low energy muon experiments such as mu2e and g-2 have a limited energy spread acceptance. Following techniques developed in muon cooling studies and the MICE experiment, the number of muons within the desired energy spread can be increased by the matched use of wedge absorbers. More generally, the phase space of muon beams can be manipulated by absorbers in beam transport lines. Applications with simulation results are presented.

  14. Stratification and salt-wedge in the Seomjin river estuary under the idealized tidal influence

    Science.gov (United States)

    Hwang, Jin Hwan; Jang, Dongmin; Kim, Yong Hoon

    2017-09-01

    Advection, straining, and vertical mixing play primary roles in the process of estuarine stratification. Estuaries can be classified as salt-wedge, partially-mixed or well-mixed depending on the vertical density structure determined by the balancing of advection, mixing and straining. In particular, straining plays a major role in the stratification of the estuarine water body along the estuarine channel. Also, the behavior of a salt wedge with a halocline shape in a stratified channel can be controlled by the competition between straining and mixing induced by buoyancy from the riverine source and tidal forcing. The present study uses Finite Volume Coastal Ocean Model (FVCOM) to show that straining and vertical mixing play major roles in controlling along-channel flow and stratification structures in the Seomjin river estuary (SRE) under idealized conditions. The Potential Energy Anomaly (PEA) dynamic equation quantifies the governing processes thereby enabling the determination of the stratification type. By comparing terms in the equation, we examined how the relative strengths of straining and mixing alter the stratification types in the SRE due to changes in river discharge and the depth resulting from dredging activities. SRE under idealized tidal forcing tends to be partially-mixed based on an analysis of the balance between terms and the vertical structure of salinity, and the morphological and hydrological change in SRE results in the shift of stratification type. While the depth affects the mixing, the freshwater discharge mainly controls the straining, and the balance between mixing and straining determines the final state of the stratification in an estuarine channel. As a result, the development and location of a salt wedge along the channel in a partially mixed and highly stratified condition is also determined by the ratio of straining to mixing. Finally, our findings confirm that the contributions of mixing and straining can be assessed by using the

  15. Global typology of urban energy use and potentials for an urbanization mitigation wedge

    OpenAIRE

    Creutzig, F.; Baiocchi, G.; Bierkandt, R.; Pichler, P.-P.; Seto, K.C.

    2015-01-01

    Many case studies of specific cities have investigated factors that contribute to urban energy use and greenhouse-gas emissions. The analysis in this study is based on data from 274 cities and three global datasets and provides a typology of urban attributes of energy use. The results highlight that appropriate policies addressing urban climate change mitigation differ with type of city. A global urbanization wedge, corresponding in particular to energy-efficient urbanization in Asia, might r...

  16. Dehydration of chlorite explains anomalously high electrical conductivity in the mantle wedges.

    Science.gov (United States)

    Manthilake, Geeth; Bolfan-Casanova, Nathalie; Novella, Davide; Mookherjee, Mainak; Andrault, Denis

    2016-05-01

    Mantle wedge regions in subduction zone settings show anomalously high electrical conductivity (~1 S/m) that has often been attributed to the presence of aqueous fluids released by slab dehydration. Laboratory-based measurements of the electrical conductivity of hydrous phases and aqueous fluids are significantly lower and cannot readily explain the geophysically observed anomalously high electrical conductivity. The released aqueous fluid also rehydrates the mantle wedge and stabilizes a suite of hydrous phases, including serpentine and chlorite. In this present study, we have measured the electrical conductivity of a natural chlorite at pressures and temperatures relevant for the subduction zone setting. In our experiment, we observe two distinct conductivity enhancements when chlorite is heated to temperatures beyond its thermodynamic stability field. The initial increase in electrical conductivity to ~3 × 10(-3) S/m can be attributed to chlorite dehydration and the release of aqueous fluids. This is followed by a unique, subsequent enhancement of electrical conductivity of up to 7 × 10(-1) S/m. This is related to the growth of an interconnected network of a highly conductive and chemically impure magnetite mineral phase. Thus, the dehydration of chlorite and associated processes are likely to be crucial in explaining the anomalously high electrical conductivity observed in mantle wedges. Chlorite dehydration in the mantle wedge provides an additional source of aqueous fluid above the slab and could also be responsible for the fixed depth (120 ± 40 km) of melting at the top of the subducting slab beneath the subduction-related volcanic arc front.

  17. Transition boundary between regular and Mach reflections for a moving shock interacting with a wedge in inviscid and polytropic air

    Science.gov (United States)

    Hryniewicki, M. K.; Gottlieb, J. J.; Groth, C. P. T.

    2017-07-01

    The transition boundary separating the region of regular reflection from the regions of single-, transitional-, and double-Mach reflections for a planar shock wave moving in air and interacting with an inclined wedge in a shock tube is studied by both analytical methods and computational-fluid-dynamic simulations. The analytical solution for regular reflection and the corresponding solutions from the extreme-angle (detachment), sonic, and mechanical-equilibrium transition criteria by von Neumann (Oblique reflection of shocks, Explosive Research Report No. 12, Navy Department, Bureau of Ordnance, U.S. Dept. Comm. Tech. Serv. No. PB37079 (1943). Also, John von Neumann, Collected Works, Pergamon Press 6, 238-299, 1963) are first revisited and revised. The boundary between regular and Mach reflection is then determined numerically using an advanced computational-fluid-dynamics algorithm to solve Euler's inviscid equations for unsteady motion in two spatial dimensions. This numerical transition boundary is determined by post-processing many closely stationed flow-field simulations, to determine the transition point when the Mach stem of the Mach-reflection pattern just disappears and this pattern then transcends into that of regular reflection. The new numerical transition boundary is shown to agree well with von Neumann's closely spaced sonic and extreme-angle boundaries for weak incident shock Mach numbers from 1.0 to 1.6, but this new boundary trends upward and above von Neumann's sonic and extreme-angle boundaries by a couple of degrees at larger shock Mach numbers from 1.6 to 4.0. Furthermore, the new numerically determined transition boundary is shown to agree well with very few available experimental data obtained from previous experiments designed to reflect two symmetrical moving oblique shock waves along a plane without a shear or boundary layer.

  18. Pulses of earthquake activity in the mantle wedge track the route of slab fluid ascent

    Science.gov (United States)

    White, Lloyd; Rawlinson, Nicholas; Lister, Gordon; Tanner, Dominique; Macpherson, Colin; Morgan, Jason

    2016-04-01

    Earthquakes typically record the brittle failure of part of the Earth at a point in space and time. These almost invariably occur within the crust or where the upper surface of subducting lithosphere interacts with the overriding mantle. However, there are also reports of rare, enigmatic earthquakes beneath rifts, above mantle plumes or very deep in the mantle. Here we report another type of mantle earthquake and present three locations where earthquake clusters occur in the mantle wedge overlying active subduction zones. These earthquake clusters define broadly circular to ellipsoidal columns that are 50 km or greater in diameter from depths between ~150 km and the surface. We interpret these rare pulses of earthquakes as evidence of near vertical transport of fluids (and associated flux-melts) from the subducted lithosphere through the mantle wedge. Detailed temporal analysis shows that most of these earthquakes occur over two-year periods, with the majority of events occurring in discrete month-long flurries of activity. As the time and location of each earthquake is recorded, pulses of seismic activity may provide information about the rate of magma ascent from the dehydrated subducted slab to sub-arc/backarc crust. This work indicates that fluids are not transported through the mantle wedge by diapirism, but through sub-vertical pathways facilitated by fracture networks and dykes on monthly to yearly time scales. These rare features move us toward solving what has until now represented a missing component of the subduction factory.

  19. Bacciger bacciger (Trematoda: Fellodistomidae) infection effects on wedge clam Donax trunculus condition.

    Science.gov (United States)

    de Montaudouin, Xavier; Bazairi, Hocein; Mlik, Karima Ait; Gonzalez, Patrice

    2014-10-16

    Wedge clams Donax trunculus inhabit high-energy environments along sandy coasts of the northeastern Atlantic Ocean and the Mediterranean Sea. Two sites were sampled monthly, one in Morocco (Mehdia), where the density was normal, and one in France (Biscarosse), where the density was very low. We tested the hypothesis that the difference in density between the sites was related to infection by the trematode parasite Bacciger bacciger. Identity of both the parasite and the host were verified using anatomical and molecular criteria. Parasite prevalence (i.e. the percentage of parasitized clams) was almost 3 times higher at Biscarosse. At this site, overall prevalence reached 32% in July and was correlated with the migration of several individuals (with a prevalence of 88%) to the sediment surface. After this peak, prevalence decreased rapidly, suggesting death of parasitized clams. The deleterious effect of B. bacciger on wedge clams was also supported by our calculations indicating that the weight of the parasite made up to 56% of the total weight of the parasitized clams. However, condition indices of trematode-free clams were also lower in Biscarosse than in Mehdia or other sites, suggesting that other factors such as pollutants or microparasites (Microcytos sp.) may alter wedge clam population fitness in Biscarosse.

  20. Exploring postoperative outcomes for ingrown toenails. NaOH vs wedge resection techniques.

    Science.gov (United States)

    Pérez-Rey, Jorge; Mediavilla-Saldaña, Lazaro; Martínez-Nova, Alfonso

    2014-03-01

    Ingrown (or ingrowing) toenail is a commonly used term for onychocryptosis, in which the nail becomes inserted into the lateral fold of the toe. The resulting effect on a person's health, well-being, and ability to work suggests the importance of clear treatment guidance, but little consensus exists. To explore postoperative recovery after surgery for ingrown toenails using chemical (sodium hydroxide (NaOH)) or mechanical (wedge resection) matricectomy and thus contribute to understanding within the field on which to base treatment guidelines. One hundred sixty-one procedures were undertaken, 94 using NaOH and 67 using wedge resection. Four measures of postoperative recovery were recorded: recurrence, infection, time to discharge, and number of postoperative visits. Patients treated with NaOH had lower rates of recurrence (p = .048) and infection (p = .03) than those treated with wedge resection, and time to discharge was shorter (p = .02), but they had more postoperative visits (p = .003). Low rates of recurrence and infection and short postoperative recovery time were found after both procedures, with a small advantage with treatment with NaOH. The authors argue for the value of clinical intervention using matricectomy in early stages to avoid complications resulting from granulation tissue growth. © 2014 by the American Society for Dermatologic Surgery, Inc. Published by Wiley Periodicals, Inc.

  1. CFD Simulations of the IHF Arc-Jet Flow: Compression-Pad/Separation Bolt Wedge Tests

    Science.gov (United States)

    Goekcen, Tahir; Skokova, Kristina A.

    2017-01-01

    This paper reports computational analyses in support of two wedge tests in a high enthalpy arc-jet facility at NASA Ames Research Center. These tests were conducted using two different wedge models, each placed in a free jet downstream of a corresponding different conical nozzle in the Ames 60-MW Interaction Heating Facility. Each panel test article included a metallic separation bolt imbedded in Orion compression-pad and heatshield materials, resulting in a circular protuberance over a flat plate. The protuberances produce complex model flowfields, containing shock-shock and shock-boundary layer interactions, and multiple augmented heating regions on the test plate. As part of the test calibration runs, surface pressure and heat flux measurements on water-cooled calibration plates integrated with the wedge models were also obtained. Surface heating distributions on the test articles as well as arc-jet test environment parameters for each test configuration are obtained through computational fluid dynamics simulations, consistent with the facility and calibration measurements. The present analysis comprises simulations of the nonequilibrium flowfield in the facility nozzle, test box, and flowfield over test articles, and comparisons with the measured calibration data.

  2. CFD Simulations of the IHF Arc-Jet Flow: Compression-Pad Separation Bolt Wedge Tests

    Science.gov (United States)

    Gokcen, Tahir; Skokova, Kristina A.

    2017-01-01

    This paper reports computational analyses in support of two wedge tests in a high enthalpy arc-jet facility at NASA Ames Research Center. These tests were conducted using two different wedge models, each placed in a free jet downstream of a corresponding different conical nozzle in the Ames 60-MW Interaction Heating Facility. Each panel test article included a metallic separation bolt imbedded in Orion compression-pad and heatshield materials, resulting in a circular protuberance over a flat plate. The protuberances produce complex model flowfields, containing shock-shock and shock-boundary layer interactions, and multiple augmented heating regions on the test plate. As part of the test calibration runs, surface pressure and heat flux measurements on water-cooled calibration plates integrated with the wedge models were also obtained. Surface heating distributions on the test articles as well as arc-jet test environment parameters for each test configuration are obtained through computational fluid dynamics simulations, consistent with the facility and calibration measurements. The present analysis comprises simulations of the non-equilibrium flow field in the facility nozzle, test box, and flow field over test articles, and comparisons with the measured calibration data.

  3. Analysis and design of wedge projection display system based on ray retracing method.

    Science.gov (United States)

    Lee, Chang-Kun; Lee, Taewon; Sung, Hyunsik; Min, Sung-Wook

    2013-06-10

    A design method for the wedge projection display system based on the ray retracing method is proposed. To analyze the principle of image formation on the inclined surface of the wedge-shaped waveguide, the bundle of rays is retraced from an imaging point on the inclined surface to the aperture of the waveguide. In consequence of ray retracing, we obtain the incident conditions of the ray, such as the position and the angle at the aperture, which provide clues for image formation. To illuminate the image formation, the concept of the equivalent imaging point is proposed, which is the intersection where the incident rays are extended over the space regardless of the refraction and reflection in the waveguide. Since the initial value of the rays arriving at the equivalent imaging point corresponds to that of the rays converging into the imaging point on the inclined surface, the image formation can be visualized by calculating the equivalent imaging point over the entire inclined surface. Then, we can find image characteristics, such as their size and position, and their degree of blur--by analyzing the distribution of the equivalent imaging point--and design the optimized wedge projection system by attaching the prism structure at the aperture. The simulation results show the feasibility of the ray retracing analysis and characterize the numerical relation between the waveguide parameters and the aperture structure for on-axis configuration. The experimental results verify the designed system based on the proposed method.

  4. Plastic ingestion by Newell's (Puffinus newelli) and wedge-tailed shearwaters (Ardenna pacifica) in Hawaii.

    Science.gov (United States)

    Kain, Elizabeth C; Lavers, Jennifer L; Berg, Carl J; Raine, André F; Bond, Alexander L

    2016-12-01

    The ingestion of plastic by seabirds has been used as an indicator of pollution in the marine environment. On Kaua'i, HI, USA, 50.0 % of Newell's (Puffinus newelli) and 76.9 % of wedge-tailed shearwater (Ardenna pacifica) fledglings necropsied during 2007-2014 contained plastic items in their digestive tract, while 42.1 % of adult wedge-tailed shearwaters had ingested plastic. For both species, the frequency of plastic ingestion has increased since the 1980s with some evidence that the mass and the number of items ingested per bird have also increased. The color of plastic ingested by the shearwaters was assessed relative to beach-washed plastics by using Jaccard's index (where J = 1 complete similarity). The color (J = 0.65-0.68) of items ingested by both species, and the type ingested by wedge-tailed shearwaters (J = 0.85-0.87), overlapped with plastic available in the local environment indicating moderate selection for plastic color and type. This study has shown that the Hawaiian populations of shearwaters, like many seabird species, provide useful but worrying insights into plastic pollution and the health of our oceans.

  5. Analysis of Mechanical Energy Transport on Free-Falling Wedge during Water-Entry Phase

    Directory of Open Access Journals (Sweden)

    Wen-Hua Wang

    2012-01-01

    Full Text Available For better discussing and understanding the physical phenomena and body-fluid interaction of water-entry problem, here mechanical-energy transport (wedge, fluid, and each other of water-entry model for free falling wedge is studied by numerical method based on free surface capturing method and Cartesian cut cell mesh. In this method, incompressible Euler equations for a variable density fluid are numerically calculated by the finite volume method. Then artificial compressibility method, dual-time stepping technique, and Roe's approximate Riemann solver are applied in the numerical scheme. Furthermore, the projection method of momentum equations and exact Riemann solution are used to calculate the fluid pressure on solid boundary. On this basis, during water-entry phase of the free-falling wedge, macroscopic energy conversion of overall body-fluid system and microscopic energy transformation in fluid field are analyzed and discussed. Finally, based on test cases, many useful conclusions about mechanical energy transport for water entry problem are made and presented.

  6. Dose conformation to the spine during palliative treatments using dynamic wedges

    Energy Technology Data Exchange (ETDEWEB)

    Ormsby, Matthew A., E-mail: Matthew.Ormsby@usoncology.com [West Texas Cancer Center at Medical Center Hospital, Odessa, TX (United States); Herndon, R. Craig; Kaczor, Joseph G. [West Texas Cancer Center at Medical Center Hospital, Odessa, TX (United States)

    2013-07-01

    Radiation therapy is commonly used to alleviate pain associated with metastatic disease of the spine. Often, isodose lines are manipulated using dynamic or physical wedges to encompass the section of spine needing treatment while minimizing dose to normal tissue. We will compare 2 methods used to treat the entire thoracic spine. The first method treats the thoracic spine with a single, nonwedged posterior-anterior (PA) field. Dose is prescribed to include the entire spine. Isodose lines tightly conform to the top and bottom vertebrae, but vertebrae between these 2 received more than enough coverage. The second method uses a combination of wedges to create an isodose line that mimics the curvature of the thoracic spine. This “C”-shaped curvature is created by overlapping 2 fields with opposing dynamic wedges. Machine constraints limit the treatment length and therefore 2 isocenters are used. Each of the 2 PA fields contributes a portion of the total daily dose. This technique creates a “C”-shaped isodose line that tightly conforms to the thoracic spine, minimizing normal tissue dose. Spinal cord maximum dose is reduced, as well as mean dose to the liver, esophagus, and heart.

  7. Double hard scattering without double counting

    Science.gov (United States)

    Diehl, Markus; Gaunt, Jonathan R.; Schönwald, Kay

    2017-06-01

    Double parton scattering in proton-proton collisions includes kinematic regions in which two partons inside a proton originate from the perturbative splitting of a single parton. This leads to a double counting problem between single and double hard scattering. We present a solution to this problem, which allows for the definition of double parton distributions as operator matrix elements in a proton, and which can be used at higher orders in perturbation theory. We show how the evaluation of double hard scattering in this framework can provide a rough estimate for the size of the higher-order contributions to single hard scattering that are affected by double counting. In a numeric study, we identify situations in which these higher-order contributions must be explicitly calculated and included if one wants to attain an accuracy at which double hard scattering becomes relevant, and other situations where such contributions may be neglected.

  8. Double hard scattering without double counting

    Energy Technology Data Exchange (ETDEWEB)

    Diehl, Markus [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Gaunt, Jonathan R. [VU Univ. Amsterdam (Netherlands). NIKHEF Theory Group; Schoenwald, Kay [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany)

    2017-02-15

    Double parton scattering in proton-proton collisions includes kinematic regions in which two partons inside a proton originate from the perturbative splitting of a single parton. This leads to a double counting problem between single and double hard scattering. We present a solution to this problem, which allows for the definition of double parton distributions as operator matrix elements in a proton, and which can be used at higher orders in perturbation theory. We show how the evaluation of double hard scattering in this framework can provide a rough estimate for the size of the higher-order contributions to single hard scattering that are affected by double counting. In a numeric study, we identify situations in which these higher-order contributions must be explicitly calculated and included if one wants to attain an accuracy at which double hard scattering becomes relevant, and other situations where such contributions may be neglected.

  9. The chronology of Late Pleistocene thermal contraction cracking derived from sand wedge OSL dating in central and southern France

    Science.gov (United States)

    Andrieux, Eric; Bateman, Mark D.; Bertran, Pascal

    2018-03-01

    Much of France remained unglaciated during the Late Quaternary and was subjected to repeated phases of periglacial activity. Numerous periglacial features have been reported but disentangling the environmental and climatic conditions they formed under, the timing and extent of permafrost and the role of seasonal frost has remained elusive. The primary sandy infillings of relict sand-wedges and composite-wedge pseudomorphs record periglacial activity. As they contain well-bleached quartz-rich aeolian material they are suitable for optically stimulated luminescence dating (OSL). This study aims to reconstruct when wedge activity took place in two regions of France; Northern Aquitaine and in the Loire valley. Results from single-grain OSL measurements identify multiple phases of activity within sand wedges which suggest that wedge activity in France occurred at least 11 times over the last 100 ka. The most widespread events of thermal contraction cracking occurred between ca. 30 and 24 ka (Last Permafrost Maximum) which are concomitant with periods of high sand availability (MIS 2). Although most phases of sand-wedge growth correlate well with known Pleistocene cold periods, the identification of wedge activity during late MIS 5 and the Younger Dryas strongly suggests that these features do not only indicate permafrost but also deep seasonal ground freezing in the context of low winter insolation. These data also suggest that the overall young ages yielded by North-European sand-wedges likely result from poor record of periglacial periods concomitant with low sand availability and/or age averaging inherent with standard luminescence methods.

  10. New angle measurement device to control the posterior tibial slope angle in medial opening wedge high tibial osteotomy.

    Science.gov (United States)

    Ogawa, Hiroyasu; Matsumoto, Kazu; Akiyama, Haruhiko

    2017-11-17

    Medial opening wedge high tibial osteotomy has been associated with an unintentional increase in the posterior tibial slope angle. We aimed to evaluate the effectiveness of a novel bone spreader angle rod to maintain the native posterior tibial slope angle in medial opening wedge high tibial osteotomy. Data from 92 consecutive knees in 83 patients who underwent medial opening wedge high tibial osteotomy for knee osteoarthritis between March 2015 and June 2016 were analysed. The osteotomy was performed without the use of a bone spreader angle rod in the first 50 cases (control group) and with the use of the angle rod in the subsequent 42 cases (angle rod group). The wedge insertion angle, defined as the angle between a line drawn along the posterior aspect of the wedge spacer and a line tangential to the posterior aspect of the femoral condyles, and the posterior tibial slope angle were evaluated on pre- and postoperative lateral knee radiographs and postoperative computed tomography images. Wedge insertion angle showed that wedge spacers were inserted in a more direct horizontal direction in the angle rod group than in the control group (16.0 ± 8.8° and 23.0 ± 10.0°, respectively, P angle was significantly smaller in the angle rod group (0.6 ± 1.6°) compared to that in the control group (3.2 ± 3.2°; P angle > 3° (outlier) was identified in 1 case (2.4%) in the angle rod group compared to 27 cases in the control group (54.0%). The direct horizontal insertion of wedge spacers with the assistance of our novel bone spreader angle rod maintains the native posterior tibial slope angle better than conventional methods. IV.

  11. The "Wedge Sign": An Imaging Sign for Aggressive Lacrimal Gland Disease.

    Science.gov (United States)

    Lorenzano, Daniele; Rose, Geoffrey E

    2017-07-01

    Lacrimal gland carcinoma can form a triangle of tissue back to the orbital apex, intraconal spread apparently being prevented by the intermuscular septum. The "wedge sign" frequency is assessed in lacrimal carcinoma, lacrimal lymphoma, or dacryoadenitis. Retrospective masked review of images from patients with biopsy-proven lacrimal gland pathology. For each patient, the presence of a triangle of tissue between the lateral rectus and lateral orbital wall and the superior rectus and the orbital roof was assessed by masked review of computed tomography or magnetic resonance imaging. For the lateral compartment, the wedge was classified as "grade 1" if it just reached the sphenoidal trigone and "grade 2" if it was a complete triangle reaching the orbital apex. Comparison of proportions was made using the Fisher exact test, using an α risk of 0.05 as clinically significant. Imaging for 116 patients was reviewed: 39 with lacrimal gland carcinoma, 37 with lymphoma, and 40 with dacryoadenitis. The lateral wedge (grade 1 or 2) was most common in patients with carcinoma (16/39; 41%), was present in 11 of 37 patients (30%) with lymphoma, and was rarest in patients with dacryadenitis (6/40; 15%) (P = 0.033). The proportion in patients with carcinoma (41%) was similar to that in patients with lymphoma (30%) (P = 0.345); the proportion in patients with lymphoma (30%) was similar to that in patients with dacryoadenitis (15%) (P = 0.170), but carcinoma (41%) was significantly different from dacryoadenitis (15%) (P = 0.013). The proportions for malignant lesions (carcinoma and lymphoma; 27/76, 36%) and benign dacryoadenitis (15%) were significantly different (P = 0.029). Likewise, a superior wedge, of any extent, was present in 10 of 39 carcinomas (26%), 2 of 40 dacryoadenitis (5%), and 6 of 37 lymphomas (16%) (P = 0.033). The "wedge sign" is most common in lacrimal gland carcinoma, but can occur in patients with severe forms of dacryoadenitis or lymphoma and generally

  12. Wedge resection for high astigmatism after penetrating keratoplasty for keratoconus: refractive and histopathologic changes.

    Science.gov (United States)

    de la Paz, María Fideliz; Sibila, Gimena Rojas; Montenegro, Gustavo; de Toledo, Juan Alvarez; Michael, Ralph; Barraquer, Rafael; Barraquer, Joaquin

    2010-06-01

    To analyze the refractive, topographic, keratometric changes and the histopathologic findings after wedge resection to correct high astigmatism after penetrating keratoplasty for keratoconus. A retrospective study was done analyzing the following parameters preoperatively and at 1, 3, and 5 years postoperatively: uncorrected visual acuity, best-corrected visual acuity, and spherical equivalent and refractive, topographic, and keratometric cylinder measures. We also studied the efficacy and safety indices, as well as the histopathologic findings of tissues submitted for pathology. A total of 22 eyes of 21 patients who underwent wedge resection in the host corneal tissue for correcting high irregular astigmatism after penetrating keratoplasty for keratoconus were included in the study. Mean follow-up time from penetrating keratoplasty to wedge resection was 18 years, whereas the mean follow-up time after wedge resection was 39.04 months (range, 12-280 months). The mean preoperative refractive, topographic, and keratometric cylinders were 11.58 +/- 3.52 diopters (D) (range, 4.5-20 D), 10.88 +/- 5.03 D (range, 2.58-21.3 D), and 11.29 +/- 4.33 D (range, 4.50-18 D), respectively. The mean postoperative refractive, topographic, and keratometric cylinders at 3 years were 4.91 +/- 2.48 D (range, 0.50-10 D), 3.38 +/- 2.10 D (range, 2.05-7.1 D), and 5.31 +/- 2.90 D (range, 0.50-9 D), respectively. The percentage of correction at 3 years of follow up was 57.5% for refractive cylinder, 68.97% for topographic cylinder, and 53.01% for keratometric cylinder. All refractive, topographic, and keratometric data showed the lowest degree of astigmatism at 3 years postoperatively, with a tendency toward regression at 5 years postoperatively. Safety index was 1.0, whereas efficacy index was 0.49. All histopathologic sections of resected tissue were consistent with keratoconus progression in the host peripheral cornea. Wedge resection is a safe and moderately effective procedure in the

  13. Formation of wedge-like pattern on VLF spectrograms observed by DEMETER

    Science.gov (United States)

    Shklyar, David; Parrot, Michel; Chum, Jaroslav; Santolik, Ondrej; Titova, Elena

    2010-05-01

    The DEMETER satellite has almost circular polar orbit, with the altitude ~ 700 km. At middle latitudes, DEMETER typically stays in the region where the height-dependent variation of the lower hybrid resonance (LHR) frequency profile forms a trough, i.e. inside the so-called LHR waveguide. In this region, LHR phenomena reveal themselves most distinctly. A striking example of such phenomena is provided by wedge-like events (WLE) registered sometimes on overview VLF spectrograms (time duration ~ 2 minutes, frequency range 0 - 20 kHz) during thunderstorm activity. A characteristic feature of these spectrograms is the presence of unusual upper and lower cutoff frequencies. The upper cutoff frequency varies rapidly, approximately in proportion to L-3, where L is McIlwain parameter on the satellite orbit. On the contrary, the lower cutoff frequency is almost constant, so that the cutoffs cross at larger L. Between these cutoffs, which thus form a wedge, intense whistlers are observed, whereas only 0+ whistlers and, probably, ducted whistlers are found outside the cutoffs. We present numerous examples of such spectrograms, and explain the formation of wedge-like structures by the wave propagation features in the inner magnetosphere, and specific position of the satellite with respect to the LHR maximum. In general terms, this explanation is as follows. WLE consists of whistler mode waves originating from lightnings and, thus, is related to thunderstorm activity. The wedge as such is formed by quasi-resonance whistler waves that cannot propagate in the region where the wave frequency is below local LHR frequency. Then, the lower frequency cutoff is determined by the LHR maximum, as quasi-resonant waves with lower frequencies originating in opposite hemisphere do not reach the satellite due to LHR reflection above it. The appearance of an upper cutoff frequency is due to another feature of unducted VLF wave propagation, which consists in trajectories merging into a limiting

  14. A comparison of the biomechanical effects of valgus knee braces and lateral wedged insoles in patients with knee osteoarthritis.

    Science.gov (United States)

    Jones, Richard K; Nester, Christopher J; Richards, Jim D; Kim, Winston Y; Johnson, David S; Jari, Sanjiv; Laxton, Philip; Tyson, Sarah F

    2013-03-01

    Increases in the external knee adduction moment (EKAM) have been associated with increased mechanical load at the knee and progression of knee osteoarthritis. Valgus knee braces and lateral wedged insoles are common approaches to reducing this loading; however no study has directly compared the biomechanical and clinical effects of these two treatments in patients with medial tibiofemoral osteoarthritis. A cross-over randomised design was used where each intervention was worn by 28 patients for a two week period. Pre- and post-intervention gait kinematic/kinetic data and clinical outcomes were collected to evaluate the biomechanical and clinical effects on the knee joint. The valgus knee brace and the lateral wedged insole significantly increased walking speed, reduced the early stance EKAM by 7% and 12%, and the knee adduction angular impulse by 8.6 and 16.1% respectively. The lateral wedged insole significantly reduced the early stance EKAM compared to the valgus knee brace (p=0.001). The valgus knee brace significantly reduced the knee varus angle compared to the baseline and lateral wedged insole. Improvements in pain and function subscales were comparable for the valgus knee brace and lateral wedged insole. There were no significant differences between the two treatments in any of the clinical outcomes; however the lateral wedged insoles demonstrated greater levels of acceptance by patients. This is the first study to biomechanically compare these two treatments, and demonstrates that given the potential role of knee loading in osteoarthritis progression, that both treatments reduce this but lateral wedge insoles appear to have a greater effect. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Saltwater wedge variation in a non-anthropogenic coastal karst aquifer influenced by a strong tidal range (Burren, Ireland)

    Science.gov (United States)

    Perriquet, Marie; Leonardi, Véronique; Henry, Tiernan; Jourde, Hervé

    2014-11-01

    Spatial and temporal changes in saltwater wedges in coastal karst aquifers are still poorly understood, largely due to complex mixing processes in these heterogeneous environments, but also due to anthropogenic forcing such as pumping, which commonly affect natural variations in wedges. The purpose of this study was first to characterize the hydrodynamic functioning of a karst aquifer in an oceanic temperate climate with little anthropogenic pressure but strongly influenced by a high tidal range and second, to evaluate the extent and movements of a saltwater wedge influenced by both the tide and the natural recharge of the aquifer. Variations in specific conductivity combined with water chemistry results from six boreholes and two lakes located in the Bell Harbour catchment (western Ireland) enabled us to assess the extent of the intrusion of the saltwater wedge into the aquifer as a function of both karst recharge and tidal movements at high/low and neap/spring tidal cycles. The marked spatial disparity of the saltwater wedge was analysed as a function of both the hydrodynamic and the structural properties of the karst aquifer. Results showed that the extent of the saltwater wedge depended not only on the intrinsic properties of the aquifer but also on the relative influence of the recharge and the tide on groundwater levels, which have opposite effects. Recharge in the Burren area throughout the year is large enough to prevent saltwater intruding more than about one kilometre from the shore. A strong tidal amplitude seems to be the motor of sudden saltwater intrusion observed in the aquifer near the shore while the position of the groundwater level seems to influence the intensity of the salinity increase. Competition between recharge and the tide thus controls the seawater inputs, hence explaining temporal and spatial changes in the saltwater wedge in this coastal karst aquifer.

  16. Assessing strain mapping by electron backscatter diffraction and confocal Raman microscopy using wedge-indented Si

    Energy Technology Data Exchange (ETDEWEB)

    Friedman, Lawrence H.; Vaudin, Mark D.; Stranick, Stephan J.; Stan, Gheorghe; Gerbig, Yvonne B.; Osborn, William; Cook, Robert F., E-mail: robert.cook@nist.gov

    2016-04-15

    The accuracy of electron backscatter diffraction (EBSD) and confocal Raman microscopy (CRM) for small-scale strain mapping are assessed using the multi-axial strain field surrounding a wedge indentation in Si as a test vehicle. The strain field is modeled using finite element analysis (FEA) that is adapted to the near-indentation surface profile measured by atomic force microscopy (AFM). The assessment consists of (1) direct experimental comparisons of strain and deformation and (2) comparisons in which the modeled strain field is used as an intermediate step. Direct experimental methods (1) consist of comparisons of surface elevation and gradient measured by AFM and EBSD and of Raman shifts measured and predicted by CRM and EBSD, respectively. Comparisons that utilize the combined FEA–AFM model (2) consist of predictions of distortion, strain, and rotation for comparison with EBSD measurements and predictions of Raman shift for comparison with CRM measurements. For both EBSD and CRM, convolution of measurements in depth-varying strain fields is considered. The interconnected comparisons suggest that EBSD was able to provide an accurate assessment of the wedge indentation deformation field to within the precision of the measurements, approximately 2×10{sup −4} in strain. CRM was similarly precise, but was limited in accuracy to several times this value. - Highlights: • We map strain by electron backscatter diffraction and confocal Raman microscopy. • The test vehicle is the multi-axial strain field of wedge-indented silicon. • Strain accuracy is assessed by direct experimental intercomparison. • Accuracy is also assessed by atomic force microscopy and finite element analyses. • Electron diffraction measurements are accurate; Raman measurements need refinement.

  17. Experiments on melt-rock reaction in the shallow mantle wedge

    Science.gov (United States)

    Mitchell, Alexandra L.; Grove, Timothy L.

    2016-12-01

    This experimental study simulates the interaction of hotter, deeper hydrous mantle melts with shallower, cooler depleted mantle, a process that is expected to occur in the upper part of the mantle wedge. Hydrous reaction experiments ( 6 wt% H2O in the melt) were conducted on three different ratios of a 1.6 GPa mantle melt and an overlying 1.2 GPa harzburgite from 1060 to 1260 °C. Reaction coefficients were calculated for each experiment to determine the effect of temperature and starting bulk composition on final melt compositions and crystallizing assemblages. The experiments used to construct the melt-wall rock model closely approached equilibrium and experienced crystallizing assemblages are dunites, harzburgites, and lherzolites (as a function of temperature). When the ratio of deeper melt to overlying mantle is 70:30, the crystallizing assemblage is a wehrlite. This shows that wehrlites, which are observed in ophiolites and mantle xenoliths, can be formed by large amounts of deeper melt fluxing though the mantle wedge during ascent. In all cases, orthopyroxene dissolves in the melt, and olivine crystallizes along with pyroxenes and spinel. The amount of reaction between deeper melts and overlying mantle, simulated here by the three starting compositions, imposes a strong influence on final melt compositions, particularly in terms of depletion. At the lowest melt/mantle ratios, the resulting melt is an extremely depleted Al-poor, high-Si andesite. As the fraction of melt to mantle increases, final melts resemble primitive basaltic andesites found in arcs globally. An important element ratio in mantle lherzolite composition, the Ca/Al ratio, can be significantly elevated through shallow mantle melt-wall rock reaction. Wall rock temperature is a key variable; over a span of lherzolite. Together, the experimental phase equilibria, melt compositions, and reaction coefficients provide a framework for understanding how melt-wall rock reaction occurs in the natural

  18. The Seismic Structure of the Mantle Wedge under Cascade Volcanoes, Northwestern U.S.A.

    Science.gov (United States)

    Levander, A.; Liu, K.; Porritt, R.; Allen, R.; Yang, Y.

    2012-04-01

    For corner flow models to be correct, the mantle wedge of a subduction zone must have an unusual lithosphere-asthenosphere boundary, as the reduced viscosities from slab dewatering, melting, and relatively hot return flow must move the lithosphere-asthenosphere boundary close to the base of the crust of the overriding plate. This should be detectable with several different seismic probes. Under a number of the volcanoes of the Cascadia arc we have identified a characteristic seismic signature in individual station Ps receiver functions and in Ps CCP image volumes made from USArray Transportable Array and Flexible Array stations. In the mantle wedge, the CCP images and the RFs show a strong negative event just below the Moho, paired with a weak to moderate positive event between 50-70 km, and a strong slab event. At most of these volcanoes, a strong negative signal also appears between 15 and 25 km depth in the crust. The signature is particularly clear under Mt. Lassen and to a lesser degree under Mt. Shasta in data from FAME (Flexible Array Mendocino Experiment), where instruments were close to the volcanic centers. Random averages using all stations throughout the western U.S., and only stations in the Cascadia backarc region show that this signature is not common to the western U.S. as a whole, nor to the backarc region in particular. Joint inversion of the Ps receiver functions and ambient noise and ballistic Rayleigh wave phase velocities (Porritt et al., 2011; Liu et al., 2012) for those volcanoes with the paired events provides 1D shear velocity profiles having common characteristics. A strong sub-Moho low velocity zone from 5 to 15 km thick gives rise to the paired negative-positive signals in the receiver functions. These mantle wedge low velocity zones, with velocities of 3.7 CIDER 2011 summer program.

  19. The Superimposed Paleocene-Miocene Tectonics of the middle part of the Nallihan Wedge (NW Turkey)

    Science.gov (United States)

    Şahin, Murat; Yaltirak, Cenk

    2015-04-01

    In the NW Turkey, the area between the suture zones of the Rhodope-Pontide Ocean and Izmir-Ankara Ocean, and North Anatolian Fault Zone (NAFZ) and Thrace-Eskişehir Fault Zone (TEFZ) is known as the Nallıhan Wedge. The shape of Nallıhan Wedge is a 90 degree counter-clockwise rotated isosceles triangle. The northwestern boundary is a part of NAFZ and the southwestern boundary is a part of TEFZ. The 160 km-long eastern boundary is located at around Beypazarı and western corner is on the Bursa Plain. Nallıhan is situated at the centre of this isosceles triangle. While all the thrusts and folds shrink towards to the west and show an imbricate-like structure, the characteristics of the folds turn into to the open folds. Thrusts faults are locally observed as blind and almost perpendicular thrusts at the fold limbs towards to the east. The rocks of the study area show different characteristics according to their types and basins of formation. On the other hand the structural properties of these rocks display the effects of the closure of the Intra-Pontide and Izmir-Ankara Oceans in between Paleocene and Early Oligocene. During Miocene, the thrust faults reactivated and a deformation formed the NEE-SWW left lateral strike-slip faults parallel to these thrust faults. Whereas the first events are related to the closure of the branches of Neo-Tethys, the Miocene deformation is probably based on the Miocene tectonics of the Western Anatolia by the reason of equivalent age of the TEFZ. In this framework, the deformation of the Nallıhan Wedge presents significant information about the period between the evolution of Paleotectonic and Neotectonic of Turkey.

  20. Lung-conserving treatment of a pulmonary oligometastasis with a wedge resection and 131Cs brachytherapy.

    Science.gov (United States)

    Wernicke, A Gabriella; Parikh, Apurva; Yondorf, Menachem; Trichter, Samuel; Gupta, Divya; Port, Jeffrey; Parashar, Bhupesh

    2013-01-01

    Soft-tissue sarcomas most frequently metastasize to the lung. Surgical resection of pulmonary metastases is the primary treatment modality. Although lobectomy is widely acknowledged as the standard procedure to treat primary pulmonary tumors, the standard for pulmonary metastases is not well defined; furthermore, compromised lung function may tip the scales in favor of a less invasive approach. Here, we report the results of a patient treated with wedge resection and intraoperative cesium-131 ((131)Cs). A 58-year-old African American female was diagnosed with the American Joint Committee on Cancer Stage IIA mixed uterine leiomyosarcoma and underwent total abdominal hysterectomy and bilateral salpingo-oophorectomy followed by adjuvant external beam radiotherapy to a total dose of 45 Gy and vaginal brachytherapy to a total dose of 20 Gy. At 2 years, a routine CT scan of the chest revealed metastasis to right upper lobe of the lung. The patient's poor pulmonary function, related to a 45 pack-year smoking history and chronic emphysema, precluded a lobectomy. After the patient underwent a lung-sparing wedge resection of the pulmonary right upper lobe metastasis and intraoperative brachytherapy with (131)Cs seeds to a total dose of 80 Gy, she remained disease free in the implanted area. At a 2-year followup, imaging continued to reveal 100% local control of the area treated with wedge resection and intraoperative (131)Cs brachytherapy. The patient had no complications from this treatment. Such treatment approach may become an attractive option in patients with oligometastatic disease and compromised pulmonary function. Copyright © 2013 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  1. Hypoplasia of L5 and wedging and pseudospondylolisthesis in patients with spondylolysis: study with MR imaging.

    Science.gov (United States)

    Wilms, G; Maldague, B; Parizel, P; Meylaerts, L; Vanneste, D; Peluso, J

    2009-04-01

    The association between L5 hypoplasia and bilateral spondylolysis was described earlier on conventional radiographs of the lumbar spine. The purpose of this study was to describe the findings on MR imaging in patients with hypoplasia of L5 and to correlate these findings with the presence of bilateral spondylolysis of L5. We studied the MR images of 22 patients with hypoplasia and posterior wedging of L5 and with bilateral spondylolysis at L5. The anteroposterior diameter of L4, L5, and S1 were measured and compared. The degree of posterior wedging of L5 was calculated. The degree of anterolisthesis was determined. The intervertebral disks of L4-L5 and L5-S1 were studied. The mean difference between the anteroposterior diameter of L4 and L5 was 3.0 mm, or 8.8% shortening of L5 compared with L4. The mean difference between the anteroposterior diameter of L5 and S1 was 4.4 mm, or 12.3% shortening of L5 compared with S1. The mean percentage posterior wedging was 24.7%. In 13 patients, there was no anterior vertebral slipping. True anterolisthesis grade I was seen in 5 patients and anterolisthesis grade II in 4 patients. Diskarthrosis with disk dehydration of L4-L5 was seen in 20 of the 22 patients. It is confirmed that hypoplasia of L5 can simulate anterolisthesis. Hypoplasia of the vertebral body of L5 can predict the presence of bilateral spondylolysis.

  2. Optical Dating Studies of southeastern Patagonian Sand Wedges in Chile and Argentina

    OpenAIRE

    Cullen, Justine Rose

    2016-01-01

    The purpose of this study was to establish a suitable single aliquot regenerative dose (SAR) optical dating protocol for K-feldspar sediments in southeast Patagonia using radiocarbon-dated Holocene dune sediments at Lago Arturo. The established protocol was then applied to sand wedge sediments found in the region in order to date periods of permafrost and to provide limiting ages on glaciation. The suitable SAR protocol incorporates a 200oC/10 s preheat for both the additive-dose and test dos...

  3. Tunable-angle wedge transducer for improved acoustophoretic control in a microfluidic chip

    DEFF Research Database (Denmark)

    Iranmanesh, I.; Barnkob, Rune; Bruus, Henrik

    2012-01-01

    We present a tunable-angle wedge ultrasound transducer for improved control of microparticle acoustophoresis in a microfluidic chip. The transducer is investigated by analyzing the pattern of aligned particles and induced acoustic energy density while varying the system geometry, transducer......-angle transducer are compared with the results from actuation by a standard planar transducer in order to decouple the influence from change in coupling angle and change in system geometry. We find in this work that the transducer coupling angle is the more important parameter compared to the concomitant change...

  4. Wedge Absorbers for Final Cooling for a High-Energy High-Luminosity Lepton Collider

    Energy Technology Data Exchange (ETDEWEB)

    Neuffer, David [Fermilab; Mohayai, Tanaz [IIT, Chicago (main); Snopok, Pavel [IIT, Chicago; Summers, Don [Mississippi U.

    2016-06-01

    A high-energy high-luminosity muon collider scenario requires a "final cooling" system that reduces transverse emittance to ~25 microns (normalized) while allowing longitudinal emittance increase. Ionization cooling using high-field solenoids (or Li Lens) can reduce transverse emittances to ~100 microns in readily achievable configurations, confirmed by simulation. Passing these muon beams at ~100 MeV/c through cm-sized diamond wedges can reduce transverse emittances to ~25 microns, while increasing longitudinal emittance by a factor of ~5. Implementation will require optical matching of the exiting beam into downstream acceleration systems.

  5. Wedge Splitting Test on Fracture Behaviour of Fiber Reinforced and Regular High Performance Concretes

    DEFF Research Database (Denmark)

    Hodicky, Kamil; Hulin, Thomas; Schmidt, Jacob Wittrup

    2013-01-01

    The fracture behaviour of three fiber reinforced and regular High Performance Concretes (HPC) is presented in this paper. Two mixes are based on optimization of HPC whereas the third mix was a commercial mix developed by CONTEC ApS (Denmark). The wedge splitting test setup with 48 cubical specimens...... parameters such as crack opening displacement (COD), fracture energy and characteristic length were experimentally determined. Experiments were performed at 1, 3, 7 and 28 days. Fracture energy, Gf, was found to increasing with age, while the characteristic length, Lch, was found to decrease....

  6. Single-port video-assisted thoracoscopic wedge resection: novel approaches in different genders.

    Science.gov (United States)

    Xu, Kai; Bian, Wen; Xie, Hongya; Ma, Haitao; Ni, Bin

    2016-08-01

    To discuss the feasibility, safety and superiority of novel approaches in single-port video-assisted thoracoscopic wedge resection in different genders. The clinical data of patients who underwent thoracoscopic pulmonary wedge resection were analysed. A total of 197 consecutive male patients from January 2012 to December 2014, and 72 female patients from June 2013 to December 2014 were included retrospectively. Of the males, 65 received a transareolar single-port procedure (TASP Group) and 132 received a standard two-port procedure (Standard Group A). Among the females, 18 were treated with a subxiphoid single-port procedure (SXSP Group), and 54 were treated with the standard procedure (Standard Group B). The general clinical materials and surgical outcomes were evaluated. All patients underwent total thoracoscopic wedge resection successfully, and no severe complications were observed. In men, there were no significant differences in operation time, blood loss, postoperative drainage amount, chest drainage duration, postoperative hospital stay or pain score on the first postoperative day (P = 0.827; 0.423; 0.174; 0.440; 0.115; 0.159, respectively). The pain scores of the TASP Group on the day before and after removal of the chest tube were lower (P = 0.006; 0.023, respectively) than those of Standard Group A, and the incision-associated paraesthesia in the third and sixth month after operation was reduced (P = 0.041; 0.026, respectively). The incision satisfaction degree was significantly improved in the TASP Group (P = 0.001). In women, there were no significant differences in blood loss, drainage amount, chest drainage duration or postoperative hospital stay (P = 0.680; 0.757; 0.651; 0.608, respectively). The operation time of the SXSP Group was longer (P = 0.000), and the pain scores on the first postoperative day and the days before and after removal were all significantly lower (P = 0.000; 0.000; 0.000, respectively) than those of the Standard Group B

  7. Wedge-Local Fields in Integrable Models with Bound States II: Diagonal S-Matrix

    Science.gov (United States)

    Cadamuro, Daniela; Tanimoto, Yoh

    2017-01-01

    We construct candidates for observables in wedge-shaped regions for a class of 1+1-dimensional integrable quantum field theories with bound states whose S-matrix is diagonal, by extending our previous methods for scalar S-matrices. Examples include the Z(N)-Ising models, the A_N-affine Toda field theories and some S-matrices with CDD factors. We show that these candidate operators which are associated with elementary particles commute weakly on a dense domain. For the models with two species of particles, we can take a larger domain of weak commutativity and give an argument for the Reeh-Schlieder property.

  8. Diffraction of an inhomogeneous plane wave by an impedance wedge in a lossy medium

    CSIR Research Space (South Africa)

    Manara, G

    1998-11-01

    Full Text Available in [1] to obtain numerically the three-dimensional (3-D) dyadic diffrac- tion coefficients for right-angle perfect electrical conductor (PEC) wedges. This method exploits the temporal causality inherent in finite- difference time-domain (FDTD) modeling... systematic study of AWE order versus the angular band of the approximation. We observed that if one expansion point is chosen for every angular sector containing a single pattern lobe/null, a Pad` approximation with 76 6149 , 77 6149 ,or77 6148 results in a...

  9. Capillary Pressure in a Wedge-Shaped Channel from Pore-Scale Imaging

    Science.gov (United States)

    Liu, Y.; Pyrak-Nolte, L. J.; Nolte, D. D.; Giordano, N. J.

    2008-12-01

    Our previous experimental investigations of capillary pressure in two-dimensional porous structures observed that, just prior to breakthrough, a deviation occurs between the externally measured capillary pressure and the capillary pressure measured from interfacial curvature. To explore this deviation, we used laser confocal microscopy to image the three-dimensional fluid distribution of two immiscible fluids in a simple wedge-shaped channel to determine whether this deviation occurs from the hidden curvature or the presence of thin films. The wedge-shaped channel was fabricated using two different approaches: two-photon polymerization and broad-illumination photolithography. Both techniques use UV-sensitive photoresist (SU-8) to construct a wedge-shaped micromodel containing a channel that is 100 microns wide at the inlet and 20 microns wide at the outlet with a constant channel depth of 40 microns. A Zeiss LSM 510 Laser Scanning Confocal Microscope was used to image the air and water distributions within the micromodel. Initially, the micromodel was saturated withwater containing Alex Fluor-488 or FITC solution by 1%wt. In these experiments, water is the wetting phase and air is the non-wetting phase. A series of drainage and imbibition cycles were performed by incrementing or decrementing the air pressure appropriately. For each increment in pressure, the system was allowed to equilibrate and then a z-stack scan of the fluid distribution was collected with the confocal microscope. The confocal images were analyzed to extract the volume saturation of air and water, the curvature of the three-dimensional fluid-air interface, and the interfacial area per volume. We observed a hysteretic relationship between capillary pressure and wetting phase saturation for the wedge-shaped channel. An analysis of the capillary pressure from interfacial curvature found that initially the calculated and measured values of capillary pressure were equal. However, as breakthrough was

  10. The optimal design of stepped wedge trials with equal allocation to sequences and a comparison to other trial designs.

    Science.gov (United States)

    Thompson, Jennifer A; Fielding, Katherine; Hargreaves, James; Copas, Andrew

    2017-12-01

    Background/Aims We sought to optimise the design of stepped wedge trials with an equal allocation of clusters to sequences and explored sample size comparisons with alternative trial designs. Methods We developed a new expression for the design effect for a stepped wedge trial, assuming that observations are equally correlated within clusters and an equal number of observations in each period between sequences switching to the intervention. We minimised the design effect with respect to (1) the fraction of observations before the first and after the final sequence switches (the periods with all clusters in the control or intervention condition, respectively) and (2) the number of sequences. We compared the design effect of this optimised stepped wedge trial to the design effects of a parallel cluster-randomised trial, a cluster-randomised trial with baseline observations, and a hybrid trial design (a mixture of cluster-randomised trial and stepped wedge trial) with the same total cluster size for all designs. Results We found that a stepped wedge trial with an equal allocation to sequences is optimised by obtaining all observations after the first sequence switches and before the final sequence switches to the intervention; this means that the first sequence remains in the control condition and the last sequence remains in the intervention condition for the duration of the trial. With this design, the optimal number of sequences is [Formula: see text], where [Formula: see text] is the cluster-mean correlation, [Formula: see text] is the intracluster correlation coefficient, and m is the total cluster size. The optimal number of sequences is small when the intracluster correlation coefficient and cluster size are small and large when the intracluster correlation coefficient or cluster size is large. A cluster-randomised trial remains more efficient than the optimised stepped wedge trial when the intracluster correlation coefficient or cluster size is small. A

  11. American Society of Biomechanics Clinical Biomechanics Award 2013: tibiofemoral contact location changes associated with lateral heel wedging--a weight bearing MRI study.

    Science.gov (United States)

    Barrance, Peter J; Gade, Venkata; Allen, Jerome; Cole, Jeffrey L

    2014-11-01

    Vertically open magnetic resonance imaging permits study of knee joint contact during weight bearing. Lateral wedging is a low cost intervention for knee osteoarthritis that may influence load distribution and contact. This study assessed the ability of feedback-assisted weight bearing magnetic resonance imaging to detect changes in tibiofemoral contact associated with lateral wedging. One knee in each of fourteen subjects with symptomatic knee osteoarthritis was studied, without specification of compartmental involvement. Knees were imaged during upright standing and at 20° knee flexion. Bilateral external heel wedges were used to provide non-wedged and 5° lateral wedging conditions. Computer modeling was used to measure the medial and lateral compartment contact patch center coordinates on the tibial plateau and the respective contact areas. Lateral heel wedging in flexion was associated with a significant anterior shift of the contact patch of the lateral femoral condyle. Changes with knee flexion were similar to previous reports: both medial and lateral contact centers moved posteriorly with flexion, and lateral condyle contact also moved laterally. Lateral condyle contact area significantly reduced with flexion, while lateral wedging did not significantly affect contact areas. In symptomatic knee osteoarthritis patients standing in knee flexion, weight bearing magnetic resonance imaging recorded an anterior shift of lateral condyle contact in response to lateral heel wedging. Future studies may investigate lateral wedging effects more specifically in candidates for this clinical intervention. Copyright © 2014 Elsevier Ltd. All rights reserved.

  12. An Experimental Investigation of Transonic Flow Past Two-Dimensional Wedge and Circular-Arc Sections Using A Mach-Zehnder Interferometer

    Science.gov (United States)

    Bryson, Arthur Earl, Jr

    1952-01-01

    Report presents the results of interferometer measurements of the flow field near two-dimensional wedge and circular-arc sections of zero angle of attack at high-subsonic and low-supersonic velocities. Both subsonic flow with local supersonic zone and supersonic flow with detached shock wave have been investigated. Pressure distributions and drag coefficients as a function of Mach number have been obtained. The wedge data are compared with the theoretical work on flow past wedge sections of Guderley and Yoshihara, Vincenti and Wagner, and Cole. Pressure distributions and drag coefficients for the wedge and circular-arc sections are presented throughout the entire transonic range of velocities.

  13. Deciding laparoscopic approaches for wedge resection in gastric submucosal tumors: a suggestive flow chart using three major determinants.

    Science.gov (United States)

    Lee, Chung-Ho; Hyun, Myung-Han; Kwon, Ye-Ji; Cho, Sung-Il; Park, Sung-Soo

    2012-12-01

    The aim of this study was to determine the optimal laparoscopic approach for wedge resection of gastric submucosal tumors (SMTs) based on tumor characteristics. Between March 2008 and June 2010, 57 patients underwent laparoscopic wedge resection for suspected gastric SMT. Of these 57 patients, 40 underwent exogastric wedge resection (EWR), with the remaining undergoing transgastric wedge resection (TWR). Fifty-seven consecutive patients undergoing surgical resection of gastric SMT were reviewed, with 40 and 17 tumors treated with EWR and TWR, respectively. The average tumor size was significantly greater in the EWR group (p = 0.004). A circular tumor location was a decisive factor for selecting the laparoscopic approach (p = 0.011). Tumors presenting with exophytic growths were predominantly found in the EWR group, and those with endophytic growth were dominant in the TWR group (p EWR or TWR revealed that tumor size (95% CI, 1.1 to 20.0; p = 0.033) and circular location of tumor (95% CI, 1.4 to 106.9; p = 0.021) were statistically significant factors. These data suggest a strategy for selection of appropriate laparoscopic wedge resection strategies based on tumor characteristics. This decision is affected by tumor size, location, and growth pattern. Copyright © 2012 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

  14. Varus Deformity of the Distal Tibia From Physeal Growth Arrest Treated Using a Titanium Metal Porous Wedge.

    Science.gov (United States)

    Bridgforth, Andrew B; Burrus, M Tyrrell; Park, Joseph S

    2016-10-01

    During a cheerleading event, a 14-year-old female sustained a right ankle physeal fracture that was treated nonoperatively with casting. She developed a distal medial tibial physeal arrest, and as the onset of menses was at age 16, she subsequently developed a varus distal tibial deformity. At the age of 19, she was no longer able to participate in collegiate cheerleading due to lateral ankle pain, ankle instability, and peroneal subluxation. After failing conservative treatment, she underwent an ankle arthroscopy, Broström-Gould procedure, peroneal retinacular repair with peroneal tenolysis, and a distal tibial medial opening wedge osteotomy using a porous titanium metal wedge and a one-third tubular plate. At 6-month follow-up, her osteotomy site showed abundant callus formation, and her lateral ankle pain had almost completely resolved. At 22-month follow-up, there were no residual ankle instability or pain complaints, and she had returned to collegiate cheerleading. This case report highlights a very useful, previously not described, application of porous titanium metal wedges for medial supramalleolar opening wedge osteotomies of the tibia. Such wedges are familiar to many foot and ankle orthopaedic surgeons and continue to have expanding indications. Therapeutic, Level IV: Case report. © 2015 The Author(s).

  15. Double outlet right ventricle

    Science.gov (United States)

    ... medlineplus.gov/ency/article/007328.htm Double outlet right ventricle To use the sharing features on this page, please enable JavaScript. Double outlet right ventricle (DORV) is a heart disease that is ...

  16. Sand provenance documents continuing accretion of the pro-wedge and erosional unroofing of the retro-wedge during arc-continent collision (Taiwan)

    Science.gov (United States)

    Garzanti, Eduardo; Padoan, Marta; Resentini, Alberto; Vezzoli, Giovanni; Castelltort, Sebastien; Tien-Shun Lin, Andrew

    2014-05-01

    The Taiwan doubly-vergent orogenic wedge developed during collision between the Luzon volcanic arc and the Chinese passive continental margin since the late Miocene (Byrne et al., 2011). In the east, the Coastal Range represents the northernmost extension of the Luzon arc and includes Neogene volcanic rocks and Plio-Pleistocene siliciclastic deposits. West of the plate boundary, running along the Longitudinal Valley, the Central Range includes polymetamorphic rocks (Tananao Complex) and a Slate Belt (Backbone Range and Hsuehshan Range). Farther to the west, the Western Foothills are a fold-thrust belt incorporating Oligo-Miocene sediments of the Chinese margin and younger foreland-basin deposits. High-resolution framework-petrography and heavy-mineral analyses were carried out on 106 samples collected from major rivers and beaches all around Taiwan in October 2012. The Coastal Range sheds feldspatho-lithic volcaniclastic sands including rich clinopyroxene-hypersthene suites with kaersutitic hornblende. Recycling of Plio-Pleistocene siliciclastics produces quartzo-lithic sands with cellular serpentinite and poor suites including hypersthene, epidote, clinopyroxene, kaersutitic hornblende and rare Cr-spinel. Similar mineralogy characterizes detritus from the Liji Mélange. Sands from the Tananao Complex are quartzo-lithic metamorphiclastic with common marble grains, sporadic metabasite, and moderately rich epidote-hornblende suites. Sands from the Slate Belt are invariably quartzo-lithic with very poor zircon-tourmaline suites. Phyllite and slate grains dominate in the east (Yuli Belt), slate grains in the middle (Backbone Range), and shale/siltstone and slate grains in the northwest (Hsuehshan Range). Neogene strata of the foothills shed litho-quartzose sands with poor suites including zircon, tourmaline, and garnet. Sands from the Tatung volcano are feldspatho-quartzo-lithic with extremely rich hypersthene-clinopyroxene suites including kaersutitic hornblende. The

  17. Double Outlet Right Ventricle

    Science.gov (United States)

    ... Right Ventricle Menu Topics Topics FAQs Double Outlet Right Ventricle Double outlet right ventricle (DORV) is a rare form of congenital heart disease. Article Info En español Double outlet right ventricle (DORV) is a rare form of congenital ...

  18. Sandbox rheometry: Co-evolution of stress and strain in Riedel- and Critical Wedge-experiments

    Science.gov (United States)

    Ritter, Malte C.; Santimano, Tasca; Rosenau, Matthias; Leever, Karen; Oncken, Onno

    2018-01-01

    Analogue sandbox experiments have been used for a long time to understand tectonic processes, because they facilitate detailed measurements of deformation at a spatio-temporal resolution unachievable from natural data. Despite this long history, force measurements to further characterise the mechanical evolution in analogue sandbox experiments have only emerged recently. Combined continuous measurements of forces and deformation in such experiments, an approach here referred to as "sandbox rheometry", are a new tool that may help to better understand work budgets and force balances for tectonic systems and to derive constitutive laws for regional scale deformation. In this article we present an experimental device that facilitates precise measurements of boundary forces and surface deformation at high temporal and spatial resolution. We demonstrate its capabilities in two classical experiments: one of strike-slip deformation (the Riedel set-up) and one of compressional accretionary deformation (the Critical Wedge set-up). In these we are able to directly observe a correlation between strain weakening and strain localisation that had previously only been inferred, namely the coincidence of the maximum localisation rate with the onset of weakening. Additionally, we observe in the compressional experiment a hysteresis of localisation with respect to the mechanical evolution that reflects the internal structural complexity of an accretionary wedge.

  19. Cervical wedge resection for treatment of pyometra secondary to transluminal cervical adhesions in six mares.

    Science.gov (United States)

    Arnold, Carolyn E; Brinsko, Steven P; Varner, Dickson D

    2015-06-15

    6 mares with pyometra secondary to transluminal cervical adhesions were examined. Reasons for hospital admission included infertility (5 mares) and acute colic (1 mare). In the 6 mares, palpation per rectum of the reproductive tract revealed uterine distention, and transrectal ultrasonography confirmed the presence of echogenic fluid accumulation within the uterus. Cervical palpation during vaginal speculum examination indicated transluminal cervical adhesions. Three mares had severe distortion of the cervix as a result of diverticula and fibrosis. All 6 mares had a diagnosis of pyometra secondary to transluminal cervical adhesions. Initially, the cervical adhesions were manually broken down to establish a patent cervical lumen to accommodate a uterine lavage catheter. A sample of the uterine content was obtained for bacteriologic culture and antimicrobial susceptibility testing, and the uterus was lavaged with 0.05% povidone-iodine solution to remove the mucopurulent exudate. Once the uterus was evacuated, cervical surgery was performed in standing mares following sedation and caudal epidural anesthesia. A full-thickness wedge-shaped defect was made in the dorsolateral aspect of the cervix that created a permanent opening to the uterus. Postoperative care included applying topical medication to the cervix to reduce the recurrence of adhesion formation. All 6 mares had patent cervices and resolution of pyometra following surgery. Cervical wedge resection enabled treatment of pyometra in mares with transluminal cervical adhesions, without the need for ovariohysterectomy.

  20. Restraint of fatigue crack growth by wedge effects of fine particles

    CERN Document Server

    Takahashi, I; Kotani, N

    2000-01-01

    Presents some experimental results which demonstrate restraint of fatigue crack growth in an Al-Mg alloy by wedge effects of fine particles. Fatigue test specimens were machined from a JIS A5083P-O Al-Mg alloy plate of 5 mm thickness and an EDM starter notch was introduced to each specimen. Three kinds of fine particles were prepared as the materials to be wedged into the fatigue cracks, i.e. magnetic particles and two kinds of alumina particles having different mean particle sizes of 47.3 mu m and 15.2 mu m. Particles of each kind were suspended in an oil to form a paste, which was applied on the specimen surface covering the notch zone prior to the fatigue tests. In order to make some fracture mechanics approaches, in situ observations of fatigue cracks were performed for the two cases using a CCD microscope, with a magnification of *1000. The crack length and the crack opening displacement (COD) at the notch root, delta , were measured. The crack retardation effect continues almost through the entire lifet...

  1. Secondary Subacromial Impingement after Valgus Closing-Wedge Osteotomy for Proximal Humerus Varus

    Directory of Open Access Journals (Sweden)

    Hirotaka Sano

    2015-01-01

    Full Text Available A 31-year-old construction worker had been suffering from both the motion pain and the restriction of elevation in his right shoulder due to severe varus deformity of humeral neck, which occurred after proximal humeral fracture. The angle for shoulder flexion and abduction was restricted to 50 and 80 degrees, respectively. Valgus closing-wedge osteotomy followed by the internal fixation using a locking plate was carried out at 12 months after injury. Postoperatively, the head-shaft angle of the humerus improved from 65 to 138 degrees. Active flexion and abduction angles improved from 80 to 135 degrees and from 50 to 135 degrees, respectively. However, the patient complained from a sharp pain with a clicking sound during shoulder abduction even after removal of the locking plate. Since subacromial steroid injection temporarily relieved his shoulder pain, we assumed that the secondary subacromial impingement was provoked after osteotomy. Thus, arthroscopic subacromial decompression was carried out at 27 months after the initial operation, which finally relieved his symptoms. In the valgus closing-wedge osteotomy, surgeons should pay attention to the condition of subacromial space to avoid causing the secondary subacromial impingement.

  2. Numerical solution of the asymmetric water impact of a wedge in three degrees of freedom

    Science.gov (United States)

    Ghazizade-Ahsaee, H.; Nikseresht, A. H.

    2013-06-01

    Impact problems associated with water entry have important applications in various aspects of naval architecture and ocean engineering. Estimation of hydrodynamic impact forces especially during the first instances after the impact is very important and is of interest. Since the estimation of hydrodynamic impact load plays an important role in safe design and also in evaluation of structural weight and costs, it is better to use a reliable and accurate prediction method instead of a simple estimation resulted by analyzing methods. In landing of flying boats, some phenomena such as weather conditions and strong winds can cause asymmetric instead of symmetric descent. In this paper, a numerical simulation of the asymmetric impact of a wedge, as the step of a flying boat, considering dynamic equations in two-phase flow is taken into account. The dynamic motion of the wedge in two-phase flow is solved based on finite volume method with volume of fluid (VOF) scheme considering dynamic equations. Then the effects of different angles of impact and water depth on the velocity change and slamming forces in an asymmetric impact are investigated. The comparison between the simulation results and experimental data verifies the accuracy of the method applied in the present study.

  3. Mantle wedge infiltrated with saline fluids from dehydration and decarbonation of subducting slab.

    Science.gov (United States)

    Kawamoto, Tatsuhiko; Yoshikawa, Masako; Kumagai, Yoshitaka; Mirabueno, Ma Hannah T; Okuno, Mitsuru; Kobayashi, Tetsuo

    2013-06-11

    Slab-derived fluids play an important role in heat and material transfer in subduction zones. Dehydration and decarbonation reactions of minerals in the subducting slab have been investigated using phase equilibria and modeling of fluid flow. Nevertheless, direct observations of the fluid chemistry and pressure-temperature conditions of fluids are few. This report describes CO2-bearing saline fluid inclusions in spinel-harzburgite xenoliths collected from the 1991 Pinatubo pumice deposits. The fluid inclusions are filled with saline solutions with 5.1 ± 1.0% (wt) NaCl-equivalent magnesite crystals, CO2-bearing vapor bubbles, and a talc and/or chrysotile layer on the walls. The xenoliths contain tremolite amphibole, which is stable in temperatures lower than 830 °C at the uppermost mantle. The Pinatubo volcano is located at the volcanic front of the Luzon arc associated with subduction of warm oceanic plate. The present observation suggests hydration of forearc mantle and the uppermost mantle by slab-derived CO2-bearing saline fluids. Dehydration and decarbonation take place, and seawater-like saline fluids migrate from the subducting slab to the mantle wedge. The presence of saline fluids is important because they can dissolve more metals than pure H2O and affect the chemical evolution of the mantle wedge.

  4. Evaluating intramural virtual electrodes in the myocardial wedge preparation: simulations of experimental conditions.

    Science.gov (United States)

    Plank, G; Prassl, A; Hofer, E; Trayanova, N A

    2008-03-01

    While defibrillation is the only means for prevention of sudden cardiac death, key aspects of the process, such as the intramural virtual electrodes (VEs), remain controversial. Experimental studies had attempted to assess intramural VEs by using wedge preparations and recording activity from the cut surface; however, applicability of this approach remains unclear. These studies found, surprisingly, that for strong shocks, the entire cut surface was negatively polarized, regardless of boundary conditions. The goal of this study is to examine, by means of bidomain simulations, whether VEs on the cut surface represent a good approximation to VEs in depth of the intact wall. Furthermore, we aim to explore mechanisms that could give rise to negative polarization on the cut surface. A model of wedge preparation was used, in which fiber orientation could be changed, and where the cut surface was subjected to permeable and impermeable boundary conditions. Small-scale mechanisms for polarization were also considered. To determine whether any distortions in the recorded VEs arise from averaging during optical mapping, a model of fluorescent recording was employed. The results indicate that, when an applied field is spatially uniform and impermeable boundary conditions are enforced, regardless of the fiber orientation VEs on the cut surface faithfully represent those intramurally, provided tissue properties are not altered by dissection. Results also demonstrate that VEs are sensitive to the conductive layer thickness above the cut surface. Finally, averaging during fluorescent recordings results in large negative VEs on the cut surface, but these do not arise from small-scale heterogeneities.

  5. Numerical study on flow rate limitation of open capillary channel flow through a wedge

    Directory of Open Access Journals (Sweden)

    Ting-Ting Zhang

    2016-04-01

    Full Text Available The flow characteristics of slender-column flow in wedge-shaped channel under microgravity condition are investigated in this work. The one-dimensional theoretical model is applied to predict the critical flow rate and surface contour of stable flow. However, the one-dimensional model overestimates the critical flow rate for not considering the extra pressure loss. Then, we develop a three-dimensional simulation method with OpenFOAM, a computational fluid dynamics tool, to simulate various phenomena in wedge channels with different lengths. The numerical results are verified with the capillary channel flow experimental data on the International Space Station. We find that the three-dimensional simulation perfectly predicts the critical flow rates and surface contours under various flow conditions. Meanwhile, the general behaviors in subcritical, critical, and supercritical flow are studied in three-dimensional simulation considering variations of flow rate and open channel length. The numerical techniques for three-dimensional simulation is validated for a wide range of configurations and is hopeful to provide valuable guidance for capillary channel flow experiment and efficient liquid management in space.

  6. Living on the wedge: female control of paternity in a cooperatively polyandrous cichlid.

    Science.gov (United States)

    Kohda, Masanori; Heg, Dik; Makino, Yoshimi; Takeyama, Tomohiro; Shibata, Jun-ya; Watanabe, Katsutoshi; Munehara, Hiroyuki; Hori, Michio; Awata, Satoshi

    2009-12-07

    Theories suggest that, in cooperatively breeding species, female control over paternity and reproductive output may affect male reproductive skew and group stability. Female paternity control may come about through cryptic female choice or female reproductive behaviour, but experimental studies are scarce. Here, we show a new form of female paternity control in a cooperatively polyandrous cichlid fish (Julidochromis transcriptus), in which females prefer wedge-shaped nesting sites. Wedge-shaped sites allowed females to manipulate the siring success of the group member males by spawning the clutch at the spot where the large males were just able to enter and fertilize the outer part of the clutch. Small males fertilized the inner part of the clutch, protected from the large aggressive males, leading to low male reproductive skew. Small males provided more brood care than large males. Multiple paternity induced both males to provide brood care and reduced female brood care accordingly. This is, to our knowledge, the first documented case in a species with external fertilization showing female mating behaviour leading to multiple male paternity and increased male brood care as a result.

  7. Effect of Ferrite Magnetic Wedge on Capacitor Motor Characteristics in Triac Control

    Science.gov (United States)

    Kaga, Akio; Anazawa, Yoshihisa; Tajima, Katsubumi

    1991-07-01

    Split-phase capacitor motors are commonly used to drive household electric appliances. The motor has some slots and teeth to embed electric conductors or coils. The presence of the slots and teeth induces the variation of magnetic reluctance through the magnetic circuit to introduce heavy pulsation of the air gap flux. Thus, the voltage, current and torque of the motor become oscillative to increase the electric power loss and finally to reduce the motor efficiency. First, the authors discuss the characteristics of a 3-phase cage-type induction motor in which the ferrite magnetic wedges have been installed into the stator slot openings of the motor to smooth the air gap flux pulsation and to decrease the electric power loss, resulting in improved motor efficiency. If the motor is driven by the voltage source in accordance with the loading condition, more economical operation will be achieved. In this study, a nonsinusoidal voltage controlled by the switching element of a triac has been applied to a capacitor motor with wedges of ferrite magnetic materials. This paper reports on the interesting results obtained.

  8. The biplanar open wedge high tibial osteotomy preserving the tibial tubercle.

    Science.gov (United States)

    Hopwood, Sam; Khan, Wasim; Agarwal, Sanjeev

    2016-11-01

    High tibial osteotomy (HTO) is a treatment option for relatively young patients with isolated medial compartment arthritis of the knee. Medial open wedge osteotomies allow easier control of correction, but can lead to patella infera as a result of distalization of the tibial tubercle. This retrospective study reports results of a biplanar tibial tubercle preserving HTO, designed to preserve patellar height. The study is a retrospective analysis of 12 consecutive patients (11 men, 1 woman) average age 39.6 years who underwent the procedure between 2009 and 2012. A biplanar open wedge tibial osteotomy was performed and stabilised with a medial locking plate. Patients were allowed full weight bearing at 6 weeks. Preoperative and postoperative function was recorded on the Oxford knee score, Lysholm score and Tegner activity scale. Minimum follow up was 26 months. All patients had healing of the osteotomy with no delayed union. Eleven patients reported improvement in symptoms with an average preoperative Oxford score of 26 and postoperative score of 39 out of 48. The Lysholm score improved from 58 to 72 out of 100. There was one point improvement in Tegner activity scale. There was no statistical difference in patellar height before and one year after surgery. The correction in varus averaged 8.3°. The biplanar High tibial Osteotomy allows preservation of patellar height, while achieving desired varus correction. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

  9. Open wedge metatarsal osteotomy versus crescentic osteotomy to correct severe hallux valgus deformity

    DEFF Research Database (Denmark)

    Wester, Jens Ulrik; Hamborg-Petersen, Ellen; Herold, Niels

    2016-01-01

    BACKGROUND: Different techniques of proximal osteotomies have been introduced to correct severe hallux valgus. The open wedge osteotomy is a newly introduced method for proximal osteotomy. The aim of this prospective randomized study was to compare the radiological and clinical results after...... operation for severe hallux valgus, comparing the open wedge osteotomy to the crescentic osteotomy which is our traditional treatment. METHODS: Forty-five patients with severe hallux valgus (hallux valgus angle >35̊, and intermetatarsal angle >15̊) were included in this study. The treatment was proximal...... and 12 months after the operation. RESULTS: In group 1 the hallux valgus angle decreased from 39.0̊ to 24.1̊ after 4 months and 27.9̊ after 12 months. In group 2 the angle decreased from 38.3̊ to 21.4̊ after 4 months and 27.0̊ after 12 months. The intermetatarsal angle in group 1 was 19.0̊ preoperatively...

  10. High prevalence of thoracic vertebral deformities and discal wedging in ankylosing spondylitis patients with hyperkyphosis.

    Science.gov (United States)

    Geusens, P; Vosse, D; van der Heijde, D; Vanhoof, J; van Tubergen, A; Raus, J; van der Linden, S

    2001-08-01

    To study the prevalence of deformities of vertebrae and intervertebral discs in patients with ankylosing spondylitis (AS) in relation to fixed hyperkyphosis of the spine. Altogether 50 patients (15 women, 35 men) with AS were studied. Hyperkyphosis was measured by the occiput to wall distance (OWD). Anterior (Ha), mid- (Hm), and posterior height (Hp) of the vertebrae and intervertebral discs were measured on lateral radiographs of the thoracic (Th5-Th12) and lumbar spine (L1-L5). Vertebral shapes were analyzed according to McCloskey, et al. Wedging of discs was calculated as Ha/Hp. Hyperkyphosis was defined as OWD > 1 cm. In the thoracic spine, the prevalence of vertebral deformities was higher in patients with hyperkyphosis (n = 38) compared to patients without hyperkyphosis (n = 12) (45% vs 8%; p = 0.01). The prevalence of thoracic vertebral deformities in patients with hyperkyphosis differed little between men and women (39% vs 58%; p > 0.10) and among patients above and below the age of 45 years (50% vs 33%; p > 0.10). Patients with one or more deformed thoracic vertebrae had a higher mean OWD than patients without deformed vertebrae (12 +/- 7 vs 7 +/- 6 cm; p hyperkyphosis. In patients with AS and hyperkyphosis, deformities of the thoracic vertebrae occur frequently and, together with wedging of the thoracic discs, contribute significantly to fixed hyperkyphosis of the spine.

  11. Lightfront holography and area density of entropy associated with quantum localization on wedge-horizon

    Energy Technology Data Exchange (ETDEWEB)

    Schroer, Bert [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)]. E-mail: schroer@cbpf.br

    2002-08-01

    The lightfront quantization of the 70s is reviewed in the more rigorous setting of lightfront (LF) restriction of free fields in which the lightfront is considered to be linear extension of the upper causal horizon of a wedge region. Particular attention is given to the change of localization structure in passing from the wedge to its horizon which results in the emergence of a transverse quantum mechanical substructure of the QFT on the horizon and its lightfront extension. The vacuum fluctuations of QFT on the LF are compressed into the direction of the lightray (where they become associated with a chiral QFT) and lead to the notion of area density of a 'split localization' entropy. To overcome the limitation of this restriction approach and include interacting theories with non-canonical short distance behavior, we introduce a new concept of algebraic lightfront holography which uses ideas of algebraic QFT, in particular the modular structure of its associated local operator algebras. In this way the localization properties of LF degrees of freedom including the absence of transverse vacuum fluctuations are confirmed to be stable against interactions. The important universality aspect of lightfront holography is emphasized. Only in this way one is able to extract from the 'split-localization' entropy a split-independent additive entropy-like measure of the entanglement of the vacuum upon restriction to the horizon algebra. (author)

  12. Ivrea mantle wedge and arc of the Western Alps (I): Geophysical evidence for the deep structure

    Science.gov (United States)

    Kissling, Edi; Schmid, Stefan M.; Diehl, Tobias

    2017-04-01

    The construction of five crustal-scale profiles across the Western Alps and the Ivrea mantle wedge integrates up-to-date geological and geophysical information and reveals important along strike changes in the overall structure of the crust of the Western Alpine arc (Schmid et al. 2017). The 3D crustal model of the Western Alps represented by these cross sections is based on recent P-velocity local earthquake tomography that compliments the previously existing wealth of geophysical information about lithosphere structure in the region. As part of Adria mantle lithosphere exhibiting strong upward bending toward the plate boundary along the inner arc of the Western Alps, the well-known Ivrea body plays a crucial role in our tectonic model. Until recently, however, the detailed 3D geometry of this key structure was only poorly constrained. In this study we present a review of the many seismic data in the region and we document the construction of our 3D lithosphere model by principles of multidisciplinary seismic tomography. Reference: Stefan M. Schmid, Edi Kissling, Douwe J.J. van Hinsbergen, Giancarlo Molli (2017). Ivrea mantle wedge and arc of the Western Alps (2): Kinematic evolution of the Alps-Apennines orogenic system. Abstract Volume EGU 2017.

  13. Transferring linear motion of an optical wedge to rotational frequency shift in an orbital angular momentum interferometer

    Science.gov (United States)

    Jia, Qikun; Qiu, Xiaodong; Wu, Ziwen; Zhang, Wuhong; Chen, Lixiang

    2017-08-01

    We build a modified Mach-Zehnder (M-Z) interferometer with an embedded Dove prism in one arm to observe the interference between two conjugate orbital angular momentum (OAM) beams. By inserting and moving an optical wedge vertically in the other arm, we find that its linear motion can induce a rotational frequency shift equivalently, as a consequence of phase transfer from the path difference to the azimuthal difference between two OAM beams. The micron-scale movement of the wedge is driven by a compact motorized translation stage and is manifested by a significant rotation of the interference petal-like patterns. Our scheme offers an accurate method to measure the optical wedge angle with a simple method of digital image processing. This work may also find potential applications in the field of velocity sensing or temperature sensing.

  14. [The case of a collar-bone wedge-fracture caused by the impact of safety-belt clasp].

    Science.gov (United States)

    Bloch-Bogusławska, Elzbieta; Wolska, Ewa

    2003-01-01

    In this study the case of a collar--bone wedge--fracture caused by the impact of safety--belt clasp was described. The presence of wedge--fracture is proof of an active mechanism of injury. This kind of fracture was described in traffic accidents as a Messerer fracture so far. The case of a wedge--fracture of the ulnar caused by impact of a baseball bat was also described. This study proves that Messerer fractures of bones are not characteristic only for long bones but may be connected with other types of bones if only the power of impact is strong enough to cause excessive bending of the bone trunk.

  15. Surgeons’ Volume-Outcome Relationship for Lobectomies and Wedge Resections for Cancer Using Video-Assisted Thoracoscopic Techniques

    Directory of Open Access Journals (Sweden)

    Guy David

    2012-01-01

    Full Text Available This study examined the effect of surgeons’ volume on outcomes in lung surgery: lobectomies and wedge resections. Additionally, the effect of video-assisted thoracoscopic surgery (VATS on cost, utilization, and adverse events was analyzed. The Premier Hospital Database was the data source for this analysis. Eligible patients were those of any age undergoing lobectomy or wedge resection using VATS for cancer treatment. Volume was represented by the aggregate experience level of the surgeon in a six-month window before each surgery. A positive volume-outcome relationship was found with some notable features. The relationship is stronger for cost and utilization outcomes than for adverse events; for thoracic surgeons as opposed to other surgeons; for VATS lobectomies rather than VATS wedge resections. While there was a reduction in cost and resource utilization with greater experience in VATS, these outcomes were not associated with greater experience in open procedures.

  16. The Effects of a Heel Wedge on Hip, Pelvis and Trunk Biomechanics During Squatting in Resistance Trained Individuals.

    Science.gov (United States)

    Charlton, Jesse M; Hammond, Connor A; Cochrane, Christopher K; Hatfield, Gillian L; Hunt, Michael A

    2017-06-01

    Barbell back squats are a popular exercise for developing lower extremity strength and power. However, this exercise has potential injury risks, particularly to the lumbar spine, pelvis, and hip joint. Previous literature suggests heel wedges as a means of favorably adjusting trunk and pelvis kinematics with the intention of reducing such injury risks. Yet no direct biomechanical research exists to support these recommendations. Therefore, the purpose of this study was to examine the effects of heel wedges compared with barefoot on minimally loaded barbell back squats. Fourteen trained male participants performed a barbell back squat in bare feet or with their feet raised bilaterally with a 2.5-cm wooden block while 3-dimensional kinematics, kinetics, and electromyograms were collected. The heel wedge condition elicited significantly less forward trunk flexion angles at peak knee flexion, and peak external hip joint moments (p ≤ 0.05) compared with barefoot conditions. However, no significant differences were observed between conditions for trunk and pelvis angle differences at peak knee flexion (p > 0.05). Lastly, no peak or root mean square differences in muscle activity were elicited between conditions (p > 0.05). Our results lend support for the suggestions provided in literature aimed at using heel wedges as a means of reducing excessive forward trunk flexion. However, the maintenance of a neutral spine, another important safety factor, is not affected by the use of heel wedges. Therefore, heel wedges may be a viable modification for reduction of excessive forward trunk flexion but not for reduction in relative trunk-pelvis flexion during barbell back squats.

  17. A 5° medial wedge reduces frontal but not saggital plane motion during jump landing in highly trained women athletes

    Directory of Open Access Journals (Sweden)

    Michael F Joseph

    2010-03-01

    Full Text Available Michael F Joseph1, Craig R Denegar1, Elaine Horn1, Bradley MacDougall1, Michael Rahl1, Jessica Sheehan1, Thomas Trojian2, Jeffery M Anderson1, James E Clark1, William J Kraemer11Department of Kinesiology, 2Department of Sports Medicine, University of Connecticut, Storrs, CT, USAAbstract: Lower extremity mechanics during landing have been linked to traumatic and nontraumatic knee injuries, particularly in women’s athletics. The effects of efforts to mitigate these risks have not been fully elucidated. We previously reported that a 5° medial wedge reduced ankle eversion and knee valgus. In the present report we further investigated the effect of a 5° medial wedge inserted in the shoes of female athletes on frontal plane hip motion, as well as ankle, knee, hip, and trunk saggital plane motion during a jump landing task. Kinematic data were obtained from 10 intercollegiate female athletes during jump landings from a 31 cm platform with and without a 5° medial wedge. Hip adduction was reduced 1.98° (95% CI 0.97–2.99° by the medial wedge but saggital plane motions were unaffected. A 5° medial wedge reduces frontal plane motion and takes the knee away from a position associated with anterior cruciate ligament injury and patellofemoral pain syndrome. Although frontal plane motion was not captured it is unlikely to have increased in a bilateral landing task. Thus, it is likely that greater muscle forces were generated in these highly trained athletes to dissipate ground reaction forces when a medial wedge was in place. Additional investigation in younger and lesser trained athletes is warranted to assess the impact of orthotic devices on knee joint mechanics.Keywords: jump landing, foot orthotic, lower extremity kinematics, knee biomechanics, knee injury

  18. Radiochromic film calibration wedge EBT2 using virtual fields; Calibracion de peliculas radiocromicos EBT2 mediante campos con cunas virtuales

    Energy Technology Data Exchange (ETDEWEB)

    Perez, M. A.; Macias, J.; Merchan, M. A.; Campo, J. L.; Moreno, J. C.; Terron, J. A.; Miras, H.; Ortiz, M.; Arrans, R.; Ortiz, A.; Fernandez, D.

    2011-07-01

    EBT2 film dosimetry after exposure to a gradient of these wedge dosimetry. In our case a virtual wedge 600. The primary objective is to automate the process, reduce the time spent in obtaining the calibration curve (color-dose). Time negligible due to the limited availability of accelerators. This method of obtaining the calibration curve provides similar results to the commonly accepted either with irradiation uniform of a single film with different dose levels (multiband ladder) or with irradiation uniform of small rectangular piece of film , decreasing by a factor about 20, the time spent. (Author)

  19. Preliminary assessment of potential underground stability (wedge and spalling) at Forsmark, Simpevarp and Laxemar sites

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Derek [Univ. of Alberta, Edmonton (Canada). Geotechnical Engineering

    2005-12-15

    In SKB's Underground Design Premises the objective in the early design phase is to estimate if there is sufficient space for the repository at a site. One of the conditions that could limit the space available is stability of the underground openings, i.e., deposition tunnels and deposition boreholes. The purpose of this report is to provide a preliminary assessment of the potential for wedge instability and spalling that may be encountered at the Forsmark, Simpevarp and Laxemar sites based on information from the site investigations program up to July 30, 2004. The rock mass spalling strength was defined using the in-situ results from SKB's Aespoe Pillar Stability Experiment and AECL's Mine-by Experiment. These experiments suggest that the rock mass spalling strength for crystalline rocks can be estimated as 0.57 of the mean laboratory uniaxial compressive strength. A probability-based methodology utilizing this in-situ rock mass spalling strength has been developed for assessing the risk for spalling in a repository at the Forsmark, Simpevarp and Laxemar sites. The in-situ stresses and the uniaxial compressive strength data from these sites were used as the bases for the analyses. Preliminary findings from all sites suggest that, generally, the risk for spalling increases as the depth of the repository increases, simply because the stress magnitudes increase with depth. The depth at which the risk for spalling is significant, depends on the individual sites which are discussed below. The greatest uncertainty in the spalling analyses for Forsmark is related to the uncertainty in the horizontal stress magnitudes and associated stress gradients with depth. The confidence in these analyses can only be increased by increasing the confidence in the stress and geology model for the site. From the analyses completed it appears that spalling in the deposition tunnels can be controlled by orienting the tunnels approximately parallel to the maximum horizontal

  20. MEASUREMENT OF THE CONTRALATERAL BREAST PHOTON AND THERMAL NEUTRON DOSES IN BREAST CANCER RADIOTHERAPY: A COMPARISON BETWEEN PHYSICAL AND DYNAMIC WEDGES.

    Science.gov (United States)

    Bagheri, Hamed; Rabie Mahdavi, Seyed; Shekarchi, Babak; Manouchehri, Farhad; Farhood, Bagher

    2018-01-01

    This research aimed to measure the received photon and thermal neutron doses to contralateral breast (CB) in breast cancer radiotherapy for various field sizes in presence of physical and dynamic wedges. The measurement of photon and thermal neutron doses was carried out on right breast region of RANDO phantom (as CB) for 18 MV photon beams. The dose measurements were performed by thermoluminescent dosimeter chips. These measurements obtained for various field sizes in presence of physical and dynamic wedges. The findings of this study showed that the received doses (both of the photon and thermal neutron) to CB in presence of physical wedge for 11 × 13, 11 × 17 and 11 × 21 cm2 field sizes were 5.92, 6.36 and 6.77% of the prescribed dose, respectively as well as for dynamic wedge were 2.92, 4.63 and 5.60% of the prescribed dose, respectively. The results showed that the received photon and thermal neutron doses to CB increase with increment of field sizes. The received photon and thermal neutron doses to CB in presence of physical wedge were more than dynamic wedge. According to obtained findings, it is suggested that using a dynamic wedge is preferable than physical wedge, especially for medial tangential field. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. HF wedge #1" detail of the wedge tip taken at VNIITF in the construction workshop. The jig mounted on top is used to measure the conformity to the drawings.

    CERN Multimedia

    Official photographer of VNIITF (photo scanned by T. Camporesi)

    2001-01-01

    The photo has been taken as documetation of the acceptance procedure of the first wedge for the very forward calorimeter of CMS (HF). The detail shows the holes where the quartz fibers are going to be stuffed and the jig used to measure that the geometry was within the specified tolerances and that the geometry alignement track was conforming to the specifications.

  2. Reporting quality of stepped wedge design randomized trials: a systematic review protocol

    Directory of Open Access Journals (Sweden)

    Thabane A

    2016-07-01

    Full Text Available Alex Thabane,1,2 Brittany B Dennis,3,4 Olga Gajic-Veljanoski,3,9,10 James Paul,2,3 Lehana Thabane2,3,5-8 1Life Sciences Program, Queen’s University, Kingston, ON, Canada; 2Department of Anesthesia, McMaster University Hamilton ON, 3Department of Clinical Epidemiology and Biostatistics, McMaster University, Hamilton ON, Canada; 4St. George’s University of London, London England, UK; 5Population Health Research Institute, Hamilton Health Sciences, 6Department of Pediatrics, McMaster University, Hamilton, ON, Canada; 7Centre for Evaluation of Medicine, 8Biostatistics Unit, Father Sean O’Sullivan Research Centre, St Joseph’s Healthcare, Hamilton, ON, Canada; 9Department of Medicine, McMaster University, Hamilton ON, Canada; 10Hamilton Health Sciences, St. Peter’s Hospital, Hamilton, ON Canada Background: Stepped wedge design (SWD is a cluster randomized controlled trial (RCT design that sequentially rolls out intervention to all clusters at varying time points. Being a relatively new design method, reporting quality has yet to be explored, and this review will seek to fill this gap in knowledge. Objectives: The objectives of this review are: 1 to assess the quality of SWD trial reports based on the CONSORT guidelines or CONSORT extension to cluster RCTs; 2 to assess the completeness of reporting of SWD trial abstracts using the CONSORT extension for abstracts; 3 to assess the reporting of sample size details in SWD trial reports or protocols; 4 to assess the completeness of reporting of SWD trial protocols according to SPIRIT guidelines; 5 to assess the consistency between the trial registration information and final SWD trial reports; and 6 to assess the consistency of what is reported in the abstracts and main text of the SWD trial reports. We will also explore factors that are associated with the completeness of reporting. Methods: We will search MEDLINE, EMBASE, Web of Science, CINAHL, and PsycINFO for all randomized controlled trials

  3. Posterior wedge osteotomy and debridement for Andersson lesion with severe kyphosis in ankylosing spondylitis.

    Science.gov (United States)

    Liang, Yan; Tang, Xiangyu; Zhao, Yongfei; Wang, Zheng

    2017-03-31

    Andersson lesion is a well-known complication in ankylosing spondylitis. Recently, owing to the worry about the healing of fracture, some scholars advocated additional anterior surgery or other procedures were necessary, which increase the risk of the nerve injury. The purpose of this study is to introduce our experience and to explore the efficacy and feasibility of posterior wedge osteotomy and debridement through Andersson Lesion for surgical treatment of severe kyphosis in ankylosing spondylitis. From January 2012 to January 2014, a retrospective study of 14 Andersson lesion patients with severe kyphosis in ankylosing spondylitis treated with surgery was completed with an at least 2-year follow-up. The debridement procedure, before posterior wedge osteotomy in posterior approach, must scrape all sclerosis bone until healthy cancellous bone appears. Radiographic and clinical results and complications were assessed with an average follow-up of 24 months. The CT scan was obtained preoperatively and at the final follow-up to assess the displacement of the fracture preoperatively, the safety of screw insertion, the healing of the fracture at the final follow-up. The Bridwell interbody fusion grading system was used to assess the healing of the fracture. Local kyphosis was substantially corrected from 51.7 ± 15.6 to 7.1 ± 19.5, with a mean correction of 44°. The global kyphosis (GK) changed from 60.6 ± 28.3 to 20.3 ± 10.3 (P = 0.000). The mean VAS back pain scores decreased from 6.7 ± 0.8 preoperatively to 0.75 ± 0.6 after a 2-year follow-up (P = 0.000). The ODI score improved from 60.56 ± 15.1% preoperatively to 23.46 ± 8.2% after a 2-year follow-up (P = 0.000). The CT scan showed solid fusion at the level of the AL, and no internal fixation loose. All patients achieved grade 1 fusion. No major complication occurred. The posterior wedge osteotomy and debridement through AL can be used to correct the severe

  4. The double identity of linguistic doubling.

    Science.gov (United States)

    Berent, Iris; Bat-El, Outi; Brentari, Diane; Dupuis, Amanda; Vaknin-Nusbaum, Vered

    2016-11-29

    Does knowledge of language consist of abstract principles, or is it fully embodied in the sensorimotor system? To address this question, we investigate the double identity of doubling (e.g., slaflaf, or generally, XX; where X stands for a phonological constituent). Across languages, doubling is known to elicit conflicting preferences at different levels of linguistic analysis (phonology vs. morphology). Here, we show that these preferences are active in the brains of individual speakers, and they are demonstrably distinct from sensorimotor pressures. We first demonstrate that doubling in novel English words elicits divergent percepts: Viewed as meaningless (phonological) forms, doubling is disliked (e.g., slaflaf Language, and their capacity to do so depends on the structure of their spoken language (English vs. Hebrew). These results demonstrate that linguistic preferences doubly dissociate from sensorimotor demands: A single stimulus can elicit diverse percepts, yet these percepts are invariant across stimulus modality--for speech and signs. These conclusions are in line with the possibility that some linguistic principles are abstract, and they apply broadly across language modality.

  5. SU-E-T-143: Effect of Physical and Virtual Wedges on the Surface Dose at Various SSD for 6 and 15 MV Photon Beam.

    Science.gov (United States)

    Yadav, Girigesh; Sinha, S N; Ashokkumar, S; Raman, Kothanda; Mishra, M; Thiyagarajan, Rajesh; Yadav, R S

    2012-06-01

    To study the effect of the virtual wedge and physical wedge filters on the surface and build-up region doses for 6 and 15MV high-energy photon beams for different field sizes and various source to surface distance(SSD). The measurements were made in water equivalent (PMMA) solid phantom in the build-up region at various SSD for various field sizes using virtual and physical wedge filters having different angles. A parallel-plate ion chamber (Markus) was used to measure the percent depth doses at surface and buildup region. Plane parallel ion chamber with fixed plate separation on the surface and buildup region would perturbate the dose measured, to get the proper dose over response correction factor was used. The percentage depth dose at surface (PDD0) increased as the field size increased for open, virtual, and physical wedged beams. For open, 30 degree physical, and virtual wedged beams, the surface doses were found to be 15.4%, 11.2%, and 15.2% with 6-MV photons and 11.2%, 9.4%, 11.2% with 15-MV photons, respectively, at 10 × 10 cm(2) field size at 100cm SSD.As SSD increases percentage depth dose at surface (PDD0) decreases for open,physical and virtual wedge field. Percentage depth dose at surface (PDD0) of virtual wedged beams were similar to those of open beams. PDD0 of physical wedged beams were lower than those of open and virtual wedged beams. Surface doses for both PW and VW increases with field size and small increase in surface dose for both PW and VW fields as wedge angle increases especially for large fields. © 2012 American Association of Physicists in Medicine.

  6. Project Half Double

    DEFF Research Database (Denmark)

    Svejvig, Per; Ehlers, Michael; Adland, Karoline Thorp

    activities carried out within the framework of the projects. The formal part of Project Half Double was initiated in June 2015. We started out by developing, refining and testing the Half Double methodology on seven pilot projects in the first phase of the project, which will end June 2016. The current...... many of the key performance indicators associated with them can be evaluated (Grundfos and Siemens Wind Power). In addition to the current status of delivering impact faster for the seven pilot projects, it is important to highlight that Project Half Double phase 1 has planted many seeds in the pilot...... organisations concerning project methodology and beyond. The many learning points from each pilot project show that Project Half Double has left its clear footprint in the pilot organisations, and that the Half Double methodology has evolved and developed very much during Project Half Double phase 1....

  7. Brightly and directionally luminescent single-walled carbon nanotubes in a wedge cavity

    Science.gov (United States)

    Zhou, Weihang; Zhang, Yingjun; Zhang, Xinhan; Tian, Chuan; Xu, Chunyan

    2017-10-01

    Single-walled carbon nanotubes suffer severely from their extremely low luminescence quantum yield and spectral purity. In this work, we produced brightly and directionally luminescent, as well as spectrally pure, carbon nanotubes by embedding them into a wedge-shaped planar cavity. By controlling the detuning between the cavity mode and exciton emission, the photoluminescence of carbon nanotubes could be enhanced up to 60 times. Coupling efficiency, i.e., percentage of nanotube luminescence emitted into a cavity mode, was found to be detuning dependent with a maximum efficiency of ˜54%. Moreover, emission from nanotubes inside the cavity becomes highly directional. The emission angle was measured to be less than 1.8 ° , demonstrating their great potential in device applications of future optoelectronics.

  8. Investigation of superconducting thin film structures prepared by nanoscale wedge polishing

    Energy Technology Data Exchange (ETDEWEB)

    Pollithy, Martin; Hoefer, Katharina; Schinkel, Uwe; Michalowski, Peter; Grosse, Veit; Schmidl, Frank; Seidel, Paul [FSU Jena, Institute of Solid State Physics, Helmholtzweg 5, D-07743 Jena (Germany); Meier, Dagmar; Shapoval, Tanya [IFW Dresden, Institute for Metallic Materials, PO Box 270116, D-01171 Dresden (Germany)

    2009-07-01

    The performance of dc-SQUID gradiometers depends very strong on the spread of the critical parameters Ic, Rn and Ls. After the preparation of high temperature superconducting devices it could be useful to tune the superconducting properties by decrease of the film thickness. On the other hand it is often helpful for sensor applications to realise a superconducting thin film structure with a smooth surface to avoid resistive or superconducting shunts in insulating layers on the top of the superconductor. In these investigations we use a mechanical wedge polishing procedure to thin the superconducting devices (microbridges, dc-SQUIDs or dc-SQUID gradiometers) before and/or after the first measurements of the electrical properties. AFM and SEM measurements were done to characterise the film morphology. Temperature dependent measurements of the superconducting properties of microbridges, dc-SQUIDs and dc-SQUID gradiometer structures were realised. We discuss the possibilities and limitations of this procedure.

  9. Numerical simulation of natural convection in wedge-shaped domain with isothermal free surface

    Science.gov (United States)

    Yaroslavtseva, N. A.; Ivanov, N. G.

    2017-11-01

    The contribution deals with 2D laminar unsteady natural convection in a wedge-shaped reservoir model induced by the isothermal surface heating of a water basin being colder than surrounding atmosphere. The problem formulation considered corresponds to large-scale convection development during a cloudy day when the solar radiation impact is negligible. Numerical simulation was performed using an in-house Navier-Stokes code SINF. The focus of the paper is on the accurate resolution of the initial period of the convective circulation pattern development. The dependence of the predicted convective structures on the computational domain size as well as on the boundary condition at the free surface is analysed. The influence of geometry on the buoyancy-induced flow formation is discussed.

  10. Design, Performance, and Calibration of CMS Hadron-Barrel Calorimeter Wedges

    CERN Document Server

    Baiatian, G; Emeliantchik, Igor; Massolov, V; Shumeiko, Nikolai; Stefanovich, R; Damgov, Jordan; Dimitrov, Lubomir; Genchev, Vladimir; Piperov, Stefan; Vankov, Ivan; Litov, Leander; Bencze, Gyorgy; Vesztergombi, Gyorgy; Zálán, Peter; Bawa, Harinder Singh; Beri, Suman Bala; Bhatnagar, Vipin; Kaur, Manjit; Kohli, Jatinder Mohan; Kumar, Arun; Singh, Jas Bir; Acharya, Bannaje Sripathi; Banerjee, Sunanda; Banerjee, Sudeshna; Chendvankar, Sanjay; Dugad, Shashikant; Kalmani, Suresh Devendrappa; Katta, S; Mazumdar, Kajari; Mondal, Naba Kumar; Nagaraj, P; Patil, Mandakini Ravindra; Reddy, L; Satyanarayana, B; Sudhakar, Katta; Verma, Piyush; Paktinat, S; Golutvin, Igor; Kalagin, Vladimir; Kosarev, Ivan; Mescheryakov, G; Sergeyev, S; Smirnov, Vitaly; Volodko, Anton; Zarubin, Anatoli; Gavrilov, Vladimir; Gershtein, Yuri; Kaftanov, Vitali; Kisselevich, I; Kolossov, V; Krokhotin, Andrey; Kuleshov, Sergey; Litvintsev, Dmitri; Stolin, Viatcheslav; Ulyanov, A; Demianov, A; Gribushin, Andrey; Kodolova, Olga; Petrushanko, Sergey; Sarycheva, Ludmila; Vardanyan, Irina; Yershov, A; Abramov, Victor; Goncharov, Petr; Khmelnikov, Alexander; Korablev, Andrey; Korneev, Yury; Krinitsyn, Alexander; Kryshkin, V; Lukanin, Vladimir; Pikalov, Vladimir; Ryazanov, Anton; Talov, Vladimir; Turchanovich, L; Volkov, Alexey; Camporesi, Tiziano; De Visser, Theo; Vlassov, E; Aydin, Sezgin; Dumanoglu, Isa; Eskut, Eda; Kayis-Topaksu, A; Kuzucu-Polatoz, A; Onengüt, G; Ozdes-Koca, N; Cankocak, Kerem; Ozok, Ferhat; Serin-Zeyrek, M; Sever, Ramazan; Zeyrek, Mehmet; Gülmez, Erhan; Isiksal, Engin; Kaya, Mithat; Ozkorucuklu, Suat; Levchuk, Leonid; Sorokin, Pavel; Grinev, B; Lubinsky, V; Senchishin, V; Anderson, E Walter; Hauptman, John M; Elias, John E; Elvira, D; Freeman, Jim; Green, Dan; Lazic, Dragoslav; Los, Serguei; O'Dell, Vivian; Ronzhin, Anatoly; Suzuki, Ichiro; Vidal, Richard; Whitmore, Juliana; Antchev, Georgy; Hazen, Eric; Lawlor, C; Machado, Emanuel; Posch, C; Rohlf, James; Wu, Shouxiang; Adams, Mark Raymond; Burchesky, Kyle; Qiang, W; Abdullin, Salavat; Baden, Drew; Bard, Robert; Eno, Sarah Catherine; Grassi, Tullio; Jarvis, Chad; Kellogg, Richard G; Kunori, Shuichi; Skuja, Andris; Podrasky, V; Sanzeni, Christopher; Winn, Dave; Akgun, Ugur; Ayan, S; Duru, Firdevs; Merlo, Jean-Pierre; Mestvirishvili, Alexi; Miller, Michael; Norbeck, Edwin; Olson, Jonathan; Onel, Yasar; Schmidt, Ianos; Akchurin, Nural; Carrell, Kenneth Wayne; Gumu, K; Thomas, Ray; Baarmand, Marc M; Ralich, Robert; Vodopiyanov, Igor; Cushman, Priscilla; Heering, Arjan Hendrix; Sherwood, Brian; Cremaldi, Lucien Marcus; Reidy, Jim; Sanders, David A; Karmgard, Daniel John; Ruchti, Randy; Fisher, Wade Cameron; Mans, Jeremy; Tully, Christopher; De Barbaro, Pawel; Bodek, Arie; Budd, Howard; Chung, Yeon Sei; Haelen, T; Imboden, Matthias; Hagopian, Sharon; Hagopian, Vasken; Johnson, Kurtis F; Barnes, Virgil E; Laasanen, Alvin T; Pompos, Arnold

    2007-01-01

    Extensive measurements have been made with pions, electrons and muons on four production wedges of the Compact Muon Solenoid (CMS) hadron barrel (HB) calorimeter in the H2 beam line at CERN with particle momenta varying from 20 to 300 GeV/c. Data were taken both with and without a prototype electromagnetic lead tungstate crystal calorimeter (EB) in front of the hadron calorimeter. The time structure of the events was measured with the full chain of preproduction front-end electronics running at 34 MHz. Moving-wire radioactive source data were also collected for all scintillator layers in the HB. These measurements set the absolute calibration of the HB prior to first pp collisions to approximately 4%.

  11. Blueschists of the Inner Makran accretionary wedge, SE Iran: Petrography, geochemistry and thermobarometry

    Science.gov (United States)

    Hunziker, Daniela; Burg, Jean-Pierre; Caddick, Mark; Reusser, Eric; Omrani, Jafar

    2010-05-01

    Blueschist facies rocks are an essential element in all discussions related to subduction processes. Some incertitude concerns their depth of burial and subsequent exhumation mechanisms, which should involve tectonic processes sufficiently rapid to preserve mineral phases stable under high pressure - low temperature conditions. It has become crucial to understand and ascertain the thermobarometric conditions under which such rocks recrystallize in order to provide a precise record of vertical movements and thermal variations in accretionary wedges and related subduction zones. Fe3+/Fe2+ ratios of mineral phases, sodic amphiboles in particular, are important for metamorphic pressure and temperature calculations. However, these ratios are poorly known for most minerals. We approached the problem by studying the petrography, geochemistry and thermobarometry of scarcely surveyed blueschists, in northern Makran, comparing the influence of both bulk and mineral ferric/ferrous iron ratios on recalculated pressure and temperature conditions. The regional and thematic consequences of these preliminary results are discussed.

  12. Area density of localization-entropy I: the case of wedge-localization

    Energy Technology Data Exchange (ETDEWEB)

    Schroer, Bert

    2006-04-15

    Using an appropriately formulated holographic light front projection, we derive an area law for the localization-entropy caused by vacuum polarization on the horizon of a wedge region. Its area density has a simple kinematic relation to the heat bath entropy of the light front algebra. Apart from a change of parametrization the infinite light like length contribution to the light front volume factor corresponds to the short-distance divergence of the area density of the localization entropy. This correspondence is a consequence of the conformal invariance of the light front holography combined with the well-known fact that in conformality relates short to long distances. In the explicit calculation of the strength factor we use the temperature duality relation of rational chiral theories whose derivation will be briefly reviewed. We comment on the potential relevance for the understanding of Black hole entropy. (author)

  13. Null alleles are ubiquitous at microsatellite loci in the Wedge Clam (Donax trunculus).

    Science.gov (United States)

    Rico, Ciro; Cuesta, Jose Antonio; Drake, Pilar; Macpherson, Enrique; Bernatchez, Louis; Marie, Amandine D

    2017-01-01

    Recent studies have reported an unusually high frequency of nonamplifying alleles at microsatellite loci in bivalves. Null alleles have been associated with heterozygous deficits in many studies. While several studies have tested for its presence using different analytical tools, few have empirically tested for its consequences in estimating population structure and differentiation. We characterised 16 newly developed microsatellite loci and show that null alleles are ubiquitous in the wedge clam, Donax trunculus. We carried out several tests to demonstrate that the large heterozygous deficits observed in the newly characterised loci were most likely due to null alleles. We tested the robustness of microsatellite genotyping for population assignment by showing that well-recognised biogeographic regions of the south Atlantic and south Mediterranean coast of Spain harbour genetically different populations.

  14. Acute effects of lateral shoe wedges on joint biomechanics of patients with medial compartment knee osteoarthritis during stationary cycling.

    Science.gov (United States)

    Gardner, Jacob K; Klipple, Gary; Stewart, Candice; Asif, Irfan; Zhang, Songning

    2016-09-06

    Cycling is commonly prescribed for individuals with knee osteoarthritis (OA) but very little biomechanical research exists on the topic. Individuals with OA may be at greater risk of OA progression or other knee injuries because of their altered knee kinematics. This study investigated the effects of lateral wedges on knee joint biomechanics and pain in patients with medial compartment knee OA during stationary cycling. Thirteen participants with OA and 11 paired healthy participants volunteered for this study. A motion analysis system and a customized instrumented pedal were used to collect 5 pedal cycles of kinematics and kinetics, respectively, during 2 minutes of cycling in 1 neutral and 2 lateral wedge (5° and 10°) conditions. Participants pedaled at 60 RPM and an 80W workrate and rated their knee pain on a visual analog scale during each minute of each condition. There was a 22% decrease in the internal knee abduction moment with the 10° wedge. However, this finding was not accompanied by a decrease in knee adduction angle or subjective pain. Additionally, there was an increase in vertical and horizontal pedal reaction force which may negate the advantages of the decreased internal knee abduction moment. For people with medial knee OA, cycling with 10° lateral wedges may not be sufficient to slow the progression of OA beyond the neutral riding condition. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Unsteady slip flow of Carreau nanofluid over a wedge with nonlinear radiation and new mass flux condition

    Directory of Open Access Journals (Sweden)

    M. Khan

    Full Text Available This article addresses a numerical investigation for the unsteady 2D slip flow of Carreau nanofluid past a static and/or moving wedge with the nonlinear radiation. A zero nanoparticle mass flux and convective boundary conditions are implemented. Further, the most recently devised model for nanofluid is adopted that incorporates the effects of Brownian motion and thermophoresis. A set of suitable transformation is demonstrated to alter the nonlinear partial differential equations into nonlinear ordinary differential equations and then tackled numerically by employing bvp4c in Matlab package. The numerical computations for the wall heat flux (Nusselt number and wall mass flux (Sherwood number are also performed. Effects of several controlling parameters on the velocity, temperature and nanoparticles concentration are explored and discussed in detail. Our study reveals that the temperature and the associated thermal boundary layer thickness are enhancing function of the temperature ratio parameter for both shear thickening and shear thinning fluids. Moreover, it is noticed that the velocity in case of moving wedge is higher than static wedge. Keywords: Unsteady wedge flow, Carreau nanofluid, Non-linear radiation, Velocity slip and nanoparticles mass flux conditions

  16. Is it safe to perform completion lobectomy after diagnostic wedge resection using video-assisted thoracoscopic surgery?

    DEFF Research Database (Denmark)

    Holbek, Bo Laksáfoss; Petersen, René Horsleben; Hansen, Henrik Jessen

    2016-01-01

    OBJECTIVES: The objective of this study was to assess the safety of video-assisted thoracoscopic surgery (VATS) completion lobectomy (CL) for non-small cell lung cancer (NSCLC) after diagnostic wedge resection by comparing with standard VATS lobectomy (SL). METHODS: Data were retrieved from...

  17. Olistostromes are the Source of Melange in Diapirs in the Cascadia-Olympics Accretionary Wedge , NW USA

    Science.gov (United States)

    Cowan, D. S.; Brandon, M. T.

    2011-12-01

    Diapirs consisting of block-in-matrix mélange are common in the ocean-ward part of the active Cascadia-Olympics wedge. Some of these bodies and similar Neogene mélanges ["Hoh mélange"] have been interpreted as having originated in shear zones related to accretion as oceanic crust of the Juan de Fuca plate was thrust beneath the wedge. However, this interpretation is untenable. The Hoh mélange contains fragments and blocks, ranging from centimeters to kilometers in size, of basalt. The chemistry of the basalt, and the microfossils in associated mudstone, prove that the basalt is Eocene: these basalts were derived from the Crescent Formation, not the much younger oceanic crust of the Juan de Fuca plate. The Crescent basalts originally formed the lid beneath which the Cascadia-Olympics wedge of sediments was underplated. Much of the lid has been eroded, but in Miocene time it extended to the coast and contributed fragments and blocks to muddy debris flows, which were deposited as olistostromes on the subducting Juan de Fuca plate. Younger sediments buried the olistostromes, which became overpressured and mobilized as mobile masses that have intruded as diapirs and anticlinal ridges. Analogous diapiric bodies, in the broad sense, are present in other active accretionary wedges, such as the in the Lesser Antilles.

  18. 76 FR 24856 - Heavy Forged Hand Tools (i.e., Axes & Adzes, Bars & Wedges, Hammers & Sledges, and Picks...

    Science.gov (United States)

    2011-05-03

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF COMMERCE International Trade Administration Heavy Forged Hand Tools (i.e., Axes & Adzes, Bars & Wedges, Hammers & Sledges..., Department of Commerce. SUMMARY: On January 3, 2011, the Department of Commerce (``Department'') initiated a...

  19. Double sequence core theorems

    Directory of Open Access Journals (Sweden)

    Richard F. Patterson

    1999-01-01

    Full Text Available In 1900, Pringsheim gave a definition of the convergence of double sequences. In this paper, that notion is extended by presenting definitions for the limit inferior and limit superior of double sequences. Also the core of a double sequence is defined. By using these definitions and the notion of regularity for 4-dimensional matrices, extensions, and variations of the Knopp Core theorem are proved.

  20. High tibial closing wedge osteotomy for medial compartment osteoarthrosis of knee

    Directory of Open Access Journals (Sweden)

    Tuli S

    2008-01-01

    Full Text Available Background: Most patients of symptomatic osteoarthrosis of knee are associated with varus malalignment that is causative or contributory to painful arthrosis. It is rational to correct the malalignment to transfer the functional load to the unaffected or less affected compartment of the knee to relieve symptoms. We report the outcome of a simple technique of high tibial osteotomy in the medial compartment of osteoarthrosis of the knee. Materials and Methods: Between 1996 and 2004 we performed closing wedge osteotomy in 78 knees in 65 patients. The patients selected for osteotomy were symptomatic essentially due to medial compartment osteoarthrosis associated with moderate genu varum. Of the 19 patients who had bilateral symptomatic disease 11 opted for high tibial osteotomy of their second knee 1-3 years after the first operation. Preoperative grading of osteoarthrosis and postoperative function was assessed using Japanese Orthopaedic Association (JOA rating scale. Results: At a minimum follow-up of 2 years (range 2-9 years 6-10° of valgus correction at the site of osteotomy was maintained, there was significant relief of pain while walking, negotiating stairs, squatting and sitting cross-legged. Walking distance in all patients improved by two to four times their preoperative distance of 200-400 m. No patient lost any preoperative knee function. The mean JOA scoring improved from preoperative 54 (40-65 to 77 (55-85 at final follow-up. Conclusion: Closing wedge high tibial osteotomy performed by our technique can be undertaken in any setup with moderate facilities. Operation related complications are minimal and avoidable. Kirschner wire fixation is least likely to interfere with replacement surgery if it becomes necessary.

  1. Understanding slab-mantle interaction by 3D seismic imaging of reflectivity in the mantle wedge

    Science.gov (United States)

    Li, L.; Hu, H.; Li, X.; Zheng, Y.

    2016-12-01

    Fluids released from the downgoing slab can flush the overlying mantle over time and generate seismic reflectivity in the mantle. By mapping the depth, lateral spatial extent, and the strength of the reflector, we can achieve better understanding of the pervasive metasomatic process and dynamics of the mineral phase changes. We use seismic waves radiated by deep subduction-zone earthquakes to image possible reflectors shallower than the earthquakes. To mitigate the uncertainties of the source depth determination and velocity heterogeneities along the ray path, we first pick the energetic pP (or sP and sSH; lowercase, upgoing wave; upper case, downgoing after being reflected by the surface) phase as a reference phase. pP represents a ray geometry that an upgoing P wave leaving from the source is reflected by the Earth surface and emerges at the station. Any underside reflection by a reflector above the source should produce a precursory phase to the reference phase. We use our 3D elastic Kirchhoff migration to migrate these precursory phases to image possible reflectors in the mantle wedge. To do this, we have collected 3-component broadband seismic data from IRIS generated by earthquakes (magnitude >5) occurring in the time window spanning from 2006 to 2015 recorded by global seismographs to produce 3D images of the mantle wedge. We first validate our imaging algorithm in Tonga subduction zone. We examined 530373 P-waves from 567 earthquakes visually and picked 18928 high signal-to-noise traces in the imaging. In the image, discontinuities such as the Gutenberg and the `410 km' phase boundary are clearly seen. Localized reflectors due to impedance changes around 210km depth and around 330km depth are also imaged. The results agree with those in previous works. We will show results in other subduction zones, which include Java, Mariana, Japan, Kurile, and South America to systematically understand slab mantle interactions in various subduction environments.

  2. Coupled stratigraphic and structural evolution of a glaciated orogenic wedge, offshore St. Elias orogen, Alaska

    Science.gov (United States)

    Worthington, Lindsay L.; Gulick, Sean P. S.; Pavlis, Terry L.

    2010-12-01

    The St. Elias orogen is the result of ˜10 Myr of oblique convergence and flat-slab subduction in the Gulf of Alaska between North America and the Yakutat microplate. Extensive glaciation and a complex tectonic environment make this region a unique case study in which to examine the details of terrane accretion and the possible coupled influence of climate and tectonic drivers on the structural and topographic evolution of an orogenic wedge. Reflection seismic profiles across the offshore Pamplona zone fold-thrust belt, the frontal St. Elias orogenic wedge, provide constraints for quantifying Pleistocene deformation recorded in the glaciomarine Yakataga formation. The total amount of Pleistocene shortening observed varies from ˜3 to 5 mm/yr, compared to the current GPS-derived Yakutat-North America convergence rate across the St. Elias orogen of ˜45 mm/yr. Growth strata and kinematic fold analysis allow comparison of relative timing of fault activity, which reveals temporal and spatial shifting of active deformation during the glacial period: faulting localized adjacent to the coastline and at the current submarine deformation front. The abandoned, currently inactive region is colocated with the major glacial depocenter in the region, the Bering Trough. These observations imply that glacial processes such as sediment loading and focused erosion during advance-retreat cycles has a direct effect on the evolution of individual faults within the Pamplona zone and the overall deformation pattern in the offshore St. Elias margin. This information provides key constraints for understanding how climatic shifts may have affected the evolution of margin architecture during Pleistocene glacial-interglacial periods.

  3. High-resolution seismic profiles of the active wedge thrusts in the Toyama basin, central Japan

    Science.gov (United States)

    Kato, Naoko; Sato, Hiroshi; Ishiyama, Tatsuya

    2017-04-01

    Thick-Neogene sediments accumulated in the Toyama basin, Miocene failed rift formed in the opening stage of the Sea of Japan. Due to the shortening deformation since the Pliocene, NE-trending reverse faults and folds have been developed to form active fault systems. Evaluation of seismic hazards requires understanding the relationship between active fault and seismic source fault is important. To obtain complete image of the active seismogenic source fault system, we carried out the high-resolution seismic profiling across the active faults in the Toyama basin, together with the deep seismic reflection profiling (KT01: Ishiyama et al., 2016). Seismic data were acquired using two vibrator trucks (IVI, EnviroVib) and a Mini-vib (IVI T15000). Shot and receiver intervals are 10 and 12.5 m respectively. The seismic data were processed using conventional CMP-reflection methods. The obtained seismic sections across the Takashozu and Isurugi faults portrays the growth strata associated with the Plio-Quaternary reverse faulting. The seismic sections show that both structures are formed as wedge thrusts at shallower structural levels. P-wave velocity profiles obtained by refraction tomography accords well to the geologic interpretation as a wedge thrust. The depth of thrust tip of main thrust is 0.6 km to 1.5 km and located in the syn rift Miocene mudstone. As the main anticline was formed by the deep-seated thrust, this shallow thrust played a secondary role for this anticline. Our results demonstrate that high-resolution seismic profiles help to reveal source fault geometry and their activity.

  4. Deformation transients in the brittle regime: Insights from spring-wedge experiments

    Science.gov (United States)

    Rosenau, Matthias; Santimano, Tasca; Oncken, Onno

    2016-04-01

    Deformation of the earth's crust varies over timescales ranging from the seismic cycle to plate tectonic phases. Seismic cycles can generically be explained by sudden coseismic release of strain energy accumulated slowly over the interseismic period. The simplest models of such transient behavior is a spring-slider system where the spring stores elastic energy and the slider is characterized by static and dynamic friction at its base allowing cyclic occurrence of slip instabilities. Here we extend this model by allowing the slider to deform in an accretionary wedge type system. Because cyclic thrust formation is associated with bulk strain weakening this should introduce slip instabilities at the time-scale of accretionary cycles superimposed on seismic cycles which are controlled by static and dynamic friction at the wedge base. To test this hypothesis we set up sandbox-type experiments where the backwall is not rigid but elastic. We vary stiffness, friction coefficients and amount of strain weakening during fault formation and reactivation within realistic ranges when scaled to nature and monitor backwall push force and surface deformation at high resolution. We observe slip instabilities both at seismic and accretionary cycle scale. Depending on the ratio of the amount of strain weakening to elastic stiffness, shortening rate increases transiently by a factor of 2-3 during fault growth. Applied to nature our observation suggests that episodic deformation transients might be interpreted as longterm slip instabilities related to crustal weakening at all relevant spatial scales: At local scale "slow earthquakes" might be interpreted as the result of the interplay between matrix stiffness and strain weakening in fault gouge material. At regional scale, applying buckling theory, we predict that deformation zones bordered by "soft" oceanic plates (e.g. the Andes) are more susceptible to deformation transients than "stiff" intracontinental settings (e.g. the Himalaya).

  5. Evaluating Intramural Virtual Electrodes in the Myocardial Wedge Preparation: Simulations of Experimental Conditions☆

    Science.gov (United States)

    Plank, G.; Prassl, A.; Hofer, E.; Trayanova, N.A.

    2008-01-01

    While defibrillation is the only means for prevention of sudden cardiac death, key aspects of the process, such as the intramural virtual electrodes (VEs), remain controversial. Experimental studies had attempted to assess intramural VEs by using wedge preparations and recording activity from the cut surface; however, applicability of this approach remains unclear. These studies found, surprisingly, that for strong shocks, the entire cut surface was negatively polarized, regardless of boundary conditions. The goal of this study is to examine, by means of bidomain simulations, whether VEs on the cut surface represent a good approximation to VEs in depth of the intact wall. Furthermore, we aim to explore mechanisms that could give rise to negative polarization on the cut surface. A model of wedge preparation was used, in which fiber orientation could be changed, and where the cut surface was subjected to permeable and impermeable boundary conditions. Small-scale mechanisms for polarization were also considered. To determine whether any distortions in the recorded VEs arise from averaging during optical mapping, a model of fluorescent recording was employed. The results indicate that, when an applied field is spatially uniform and impermeable boundary conditions are enforced, regardless of the fiber orientation VEs on the cut surface faithfully represent those intramurally, provided tissue properties are not altered by dissection. Results also demonstrate that VEs are sensitive to the conductive layer thickness above the cut surface. Finally, averaging during fluorescent recordings results in large negative VEs on the cut surface, but these do not arise from small-scale heterogeneities. PMID:17993491

  6. The Liguride Complex of Southern Italy —a Cretaceous to Paleogene accretionary wedge

    Science.gov (United States)

    Knott, Steven D.

    1987-11-01

    The ophiolite-bearing allochthonous flysch (Liguride Complex) of the Southern Apennines, Italy, has traditionally been divided into two tectonic units: the metamorphic Frido Unit and the unmetamorphosed Cilento Unit. The two units have hitherto been considered to derive from two distinct paleogeographic domains; however, the identification of Cilento Unit sediments within Frido Unit successions implies that the sediments of both units were coeval deposits within the same sedimentary basin. Cilento Unit sediments also occur as the sedimentary cover of kilometre-scale oceanic slices within the Liguride Complex indicating deposition on oceanic basement and not continental basement as was previously considered. Thrust transport directions and sediment provenance indicate that during Late Jurassic time this ocean basin lay to the east of the Calabrian terrain and to the west of Apulia, Calabria and Apulia representing the European and African margins of Neotethys respectively. Northwestwards subduction of oceanic crust beneath the Calabrian terrain from Late Cretaceous time onwards produced an accretionary wedge which was later emplaced onto the Apulian margin during the Burdigalian collision of Calabria and Apulia. The Liguride Complex represents the obducted remains of this accretionary wedge. This interpretation contains three important implications for pre-Tertiary plate tectonic reconstructions of the western Mediterranean region, these are: (1) The Calabrian continental terrain formed part of the Iberian Plate on the north margin of Neotethys, this may have implications for the former location and continuation of the North Pyrenean Fault. (2) The existence of a continuation of the "Eo-Alpine" belt through Calabria and the Kabylies is placed in doubt thus requiring only one, constant polarity (NW-dipping) subduction direction to explain the structures now seen in these regions. (3) The existence of a transform fault between the Europe-vergent structures of Corsica

  7. Implementation of a wedged-dynamic arc therapy technique for head and neck cancer.

    Science.gov (United States)

    Ibrahim, Mohamed S; Metwaly, Mohamed; El-Sayed, El-Sayed Mahmoud; Sallam, Abdel-Sattar M

    2014-01-01

    In this study, we designed and evaluated a wedged dynamic arc therapy (W-DAT) to provide the desirable concaved-shape dose distribution to cover the target in the treatment of head and neck sequence cell carcinoma. Eight patients were treated using W-DAT. The dose prescriptions were 70 Gy and 54 Gy, in 35 fractions, to the sites of the gross planning target volume (PTV1) and the microscopic (PTV2) diseases respectively. This technique consists of four wedged half-arcs of moving multi-leaf collimator leaves to fit PTV1 and shield brain stem at all gantry rotations. These were combined with two anterior-posterior conformal fields of different weighing to improve the dose uniformity. Another two anterior-posterior conformal fields were designed to cover the PTV2. All of the eight fields were half blocked by the normal jaws so there is no dose overlap at the interface between the two targets. Referring to radiation therapy oncology group protocol 0615, 95% of the PTV1 was covered by more than 95% (66.50 Gy) of the prescribed dose, with very low dose inhomogeneity index of 0.0670 ± 0.0007. The maximum dose to 1% of the planning organ at risk volumes-brainstem didn't exceed 56.10 ± 2.17 Gy while the two parotids were well spared as they received a mean dose of 21.97 ± 3.24 Gy. Isocentric ion chamber measurements showed good agreement with the treatment planning system calculated dose with the maximum deviation of 2.40% while film measurements yielded lesser than 4.20% of the pixels failed the acceptance gamma criteria of (3 mm, 3%). W-DAT technique was approved in our department as the standard choice for the radical treatment of head and neck sequence cell carcinoma.

  8. High reliability in digital planning of medial opening wedge high tibial osteotomy, using Miniaci's method.

    Science.gov (United States)

    Elson, D W; Petheram, T G; Dawson, M J

    2015-07-01

    Pre-operative planning is essential in high tibial osteotomy (HTO). Miniaci's method employs Mikulicz's weight-bearing line and is advantageous because the point of mechanical loading is related to the known degenerative condition of the knee. Miniaci's geometrical method has been modified for an opening wedge and described for use with a digital picture archiving and communications system viewer. Reliability for this method was hypothesised to be equivalent to published reliability for landmark-based commercial software and independent of observer experience. Twenty-four patients awaiting HTO had standardised long-leg radiographs. Mikulicz's weight-bearing line was projected through the lateral compartment of the knee at Fujisawa's point. The correction angle was generated at the hinge point subtending the current and proposed ankle centres. The opening wedge was plotted to measure an opening distance. Observations were recorded twice by three observers. Agreement was reported as intraclass correlation coefficients with 95 % confidence intervals. Intra-rater agreement was excellent for the correction angle (0.965-0.985) and opening distance (0.928-0.980). If no set hinge point was used, then the inter-rater reliability was 0.986 for the correction angle and 0.984 for the opening distance. There was no discernible pattern demonstrating improved reliability from the experienced observer. Reliability is comparable to commercially based landmark software and independent of observer experience. This makes such geometrical pre-operative planning accessible to surgeons who perform HTO with insufficient frequency to justify the investment in commercial software. Diagnostic study, Level II.

  9. Prospective 5-year survival rate data following open-wedge valgus high tibial osteotomy.

    Science.gov (United States)

    Bode, Gerrit; von Heyden, Johanna; Pestka, Jan; Schmal, Hagen; Salzmann, Gian; Südkamp, Norbert; Niemeyer, Philipp

    2015-07-01

    Open-wedge high tibial osteotomy using internal plate fixation is a well-established and frequently performed treatment option for the management of medial compartment osteoarthritis (OA) in the young and active patients. The present study provides survival rate and functional outcome preoperatively and after 6, 12, 24, 36 and 60 months following open-wedge high tibial osteotomy. Hypothesis of the authors was high survival rates after 5 years with still remaining satisfying functional results. Sixty-two patients suffering from tibial conditioned knee joint varus deformity and medial compartment OA that underwent high tibial osteotomy using an internal plate fixator (TomoFix™, Synthes) were included. Functional outcome was evaluated prior to surgery and in the further clinical course using standard instruments (IKDC score, Lysholm score). Treatment failure was defined as the need for total knee arthroplasty (TKA). Fifty-one patients (mean age 46.8 ± 10.2 years) were available at a mean of 60.5 (SD ± 2.5) months (follow-up rate 82.3 %) postoperatively. Sixty-month IKDC (69.4 % SD ± 18.6) and Lysholm (76.6 SD ± 20.5) improved significantly when comparing with preoperative values (IKDC 44.6 SD ± 17.8; Lysholm 52.1 SD ± 20.8). Two of 51 subjects underwent TKA, resulting in a survival rate of 96 % among those patients followed (51 of 60; 85 %). Overall complication rate was 8.6 %. With a survival rate of over 96 % at 5 years, high tibial osteotomy seems to be a reliable treatment option with satisfying clinical outcome. Functional outcome was stable following 60 months. While a delay of the necessity for TKA seems likely with regard to the survival rate demonstrated in this article, possible avoidance needs to be demonstrated by longer follow-up studies. Therapeutic case series, Level IV.

  10. Novel Ordered Stepped-Wedge Cluster Trial Designs for Detecting Ebola Vaccine Efficacy Using a Spatially Structured Mathematical Model.

    Science.gov (United States)

    Diakite, Ibrahim; Mooring, Eric Q; Velásquez, Gustavo E; Murray, Megan B

    2016-08-01

    During the 2014 Ebola virus disease (EVD) outbreak, policy-makers were confronted with difficult decisions on how best to test the efficacy of EVD vaccines. On one hand, many were reluctant to withhold a vaccine that might prevent a fatal disease from study participants randomized to a control arm. On the other, regulatory bodies called for rigorous placebo-controlled trials to permit direct measurement of vaccine efficacy prior to approval of the products. A stepped-wedge cluster study (SWCT) was proposed as an alternative to a more traditional randomized controlled vaccine trial to address these concerns. Here, we propose novel "ordered stepped-wedge cluster trial" (OSWCT) designs to further mitigate tradeoffs between ethical concerns, logistics, and statistical rigor. We constructed a spatially structured mathematical model of the EVD outbreak in Sierra Leone. We used the output of this model to simulate and compare a series of stepped-wedge cluster vaccine studies. Our model reproduced the observed order of first case occurrence within districts of Sierra Leone. Depending on the infection risk within the trial population and the trial start dates, the statistical power to detect a vaccine efficacy of 90% varied from 14% to 32% for standard SWCT, and from 67% to 91% for OSWCTs for an alpha error of 5%. The model's projection of first case occurrence was robust to changes in disease natural history parameters. Ordering clusters in a step-wedge trial based on the cluster's underlying risk of infection as predicted by a spatial model can increase the statistical power of a SWCT. In the event of another hemorrhagic fever outbreak, implementation of our proposed OSWCT designs could improve statistical power when a step-wedge study is desirable based on either ethical concerns or logistical constraints.

  11. Novel Ordered Stepped-Wedge Cluster Trial Designs for Detecting Ebola Vaccine Efficacy Using a Spatially Structured Mathematical Model.

    Directory of Open Access Journals (Sweden)

    Ibrahim Diakite

    2016-08-01

    Full Text Available During the 2014 Ebola virus disease (EVD outbreak, policy-makers were confronted with difficult decisions on how best to test the efficacy of EVD vaccines. On one hand, many were reluctant to withhold a vaccine that might prevent a fatal disease from study participants randomized to a control arm. On the other, regulatory bodies called for rigorous placebo-controlled trials to permit direct measurement of vaccine efficacy prior to approval of the products. A stepped-wedge cluster study (SWCT was proposed as an alternative to a more traditional randomized controlled vaccine trial to address these concerns. Here, we propose novel "ordered stepped-wedge cluster trial" (OSWCT designs to further mitigate tradeoffs between ethical concerns, logistics, and statistical rigor.We constructed a spatially structured mathematical model of the EVD outbreak in Sierra Leone. We used the output of this model to simulate and compare a series of stepped-wedge cluster vaccine studies. Our model reproduced the observed order of first case occurrence within districts of Sierra Leone. Depending on the infection risk within the trial population and the trial start dates, the statistical power to detect a vaccine efficacy of 90% varied from 14% to 32% for standard SWCT, and from 67% to 91% for OSWCTs for an alpha error of 5%. The model's projection of first case occurrence was robust to changes in disease natural history parameters.Ordering clusters in a step-wedge trial based on the cluster's underlying risk of infection as predicted by a spatial model can increase the statistical power of a SWCT. In the event of another hemorrhagic fever outbreak, implementation of our proposed OSWCT designs could improve statistical power when a step-wedge study is desirable based on either ethical concerns or logistical constraints.

  12. Finite-sample corrected generalized estimating equation of population average treatment effects in stepped wedge cluster randomized trials.

    Science.gov (United States)

    Scott, JoAnna M; deCamp, Allan; Juraska, Michal; Fay, Michael P; Gilbert, Peter B

    2017-04-01

    Stepped wedge designs are increasingly commonplace and advantageous for cluster randomized trials when it is both unethical to assign placebo, and it is logistically difficult to allocate an intervention simultaneously to many clusters. We study marginal mean models fit with generalized estimating equations for assessing treatment effectiveness in stepped wedge cluster randomized trials. This approach has advantages over the more commonly used mixed models that (1) the population-average parameters have an important interpretation for public health applications and (2) they avoid untestable assumptions on latent variable distributions and avoid parametric assumptions about error distributions, therefore, providing more robust evidence on treatment effects. However, cluster randomized trials typically have a small number of clusters, rendering the standard generalized estimating equation sandwich variance estimator biased and highly variable and hence yielding incorrect inferences. We study the usual asymptotic generalized estimating equation inferences (i.e., using sandwich variance estimators and asymptotic normality) and four small-sample corrections to generalized estimating equation for stepped wedge cluster randomized trials and for parallel cluster randomized trials as a comparison. We show by simulation that the small-sample corrections provide improvement, with one correction appearing to provide at least nominal coverage even with only 10 clusters per group. These results demonstrate the viability of the marginal mean approach for both stepped wedge and parallel cluster randomized trials. We also study the comparative performance of the corrected methods for stepped wedge and parallel designs, and describe how the methods can accommodate interval censoring of individual failure times and incorporate semiparametric efficient estimators.

  13. Neutrinoless double beta decay

    Indian Academy of Sciences (India)

    2012-10-06

    Oct 6, 2012 ... The physics potential of neutrinoless double beta decay is discussed. Furthermore, experimental considerations as well as the current status of experiments are presented. Finally, an outlook towards the future, work on nuclear matrix elements and alternative processes is given. Keywords. Double beta ...

  14. Investigation of the Field Size Effect on Wedge Field Isodose Curves Angle for Two Energies; 6 & 18 MV, produced by VARIAN 2100C Linac

    Directory of Open Access Journals (Sweden)

    Mohammad Javad T ahmasebi

    2008-06-01

    Full Text Available Introduction: Nowadays,  considerable developments  in  the field  of  radiotherapy have  been  achieved.  They  include  the  advances  made  in  the  equipments  and  treatment  planning  techniques  which  require  highly complex calculations. Such achievements have made it possible to treat cancer patients not only  with  higher  radiation  dose  but  also  with  higher  precision  and  consequently  increasing  the  chance  of  curing the cancer. However, the conventional techniques requiring physical wedge are still being used  but with a lesser frequency. One of the wedge parameters needed to be measured is the wedge angle. It is  the angle that the horizontal line creates with the tilted isodose curve at a specific depth and for a certain  field size.   In this study, the variation of wedge angle for different field sizes was evaluated using dosimetric and  mathematical method.  Material and Methods: For the wedge fields with a dimension of 6×6 to 20×20 cm 2 , the wedge angle  for  two  photon  energies  of  6  and  18  MV  was  measured  by  the  dosimetric  method.  For  these  measurements, the conventional wedges having the nominal wedge angle of 15, 30, 45 & 60 were used.  The theoretical method suggested by Saw et al. is also used to indirectly calculate the slope of isodose  curve  by  the  dose  profile  and  percent  depth  dose  data.  The  dose  profile,  percentage  depth  dose  and  isodose curves were drawn for all the field sizes and the tilt of isodose curve at 10 cm depth, according to  international definition, is considered as the wedge angle. The data were obtained using the theoretical  equation of wedge angle and it was compared to the dosimetric data.  Results: The result obtained in this work shows that the wedge angle increases with the field size. For a  6×6 cm 2 field size, the calculated wedge angle has the highest

  15. Stable isotope and gas properties of two climatically contrasting (Pleistocene and Holocene ice wedges from Cape Mamontov Klyk, Laptev Sea, northern Siberia

    Directory of Open Access Journals (Sweden)

    T. Boereboom

    2013-01-01

    Full Text Available This paper presents and discusses the texture, fabric, water stable isotopes (δ18O, δD and gas properties (total gas content, O2, N2, Ar, CO2, and CH4 mixing ratios of two climatically contrasted (Holocene vs. Pleistocene ice wedges (IW-26 and IW-28 from Cape Mamontov Klyk, Laptev Sea, in northern Siberia. The two ice wedges display contrasting structures: one being of relatively "clean" ice and the other showing clean ice at its centre as well as debris-rich ice on both sides (referred to as "ice-sand wedge". Our multiparametric approach allows discrimination between three different ice facies with specific signatures, suggesting different climatic and environmental conditions of formation and various intensities and nature of biological activity. More specifically, crystallography, total gas content and gas composition reveal variable levels of meltwater infiltration and contrasting contributions from anaerobic and aerobic conditions to the biological signatures. Stable isotope data are drawn on to discuss changes in paleoenvironmental conditions and in the temporal variation of the different moisture sources for the snow feeding into the ice wedges infillings. Our data set also supports the previous assumption that the ice wedge IW-28 was formed in Pleistocene and the ice wedge IW-26 in Holocene times. This study sheds more light on the conditions of ice wedge growth under changing environmental conditions.

  16. Decarbonation and carbonation processes in the slab and mantle wedge - insights from thermomechanical modeling

    Science.gov (United States)

    Gonzalez, C. M.; Gorczyk, W.; Connolly, J. A.; Gerya, T.; Hobbs, B. E.; Ord, A.

    2013-12-01

    Subduction zones offer one of the most geologically active and complex systems to investigate. They initiate a process in which crustal sediments are recycled, mantle heterogeneities arise, and mantle wedge refertilization occurs via slab derived volatiles and magma generation. Slab derived volatiles, consisting primarily of H2O - CO2 fluids, are especially critical in subduction evolution as they rheologically weaken the mantle wedge, decrease solidus temperatures, and rock-fluid interactions result in metasomatism. While the effects of H2O in these processes have been well studied in the past decades, CO2's role remains open for much scientific study. This is partly attributed to the sensitivity of decarbonation to the thermal gradient of the subduction zone, bulk compositions (sediments, basalts, peridotites) and redox state of the mantle. Here we show benchmarking results of a subduction scenario that implements carbonation-decarbonation reactions into a fully coupled petrological-thermomechanical numerical modeling code. We resolve stable mineralogy and extract rock properties via Perple_X at a resolution of 5°C and 25 MPa. The numerical technique employed is a characteristics-based marker-in-cell technique with conservative finite-differences that includes visco-elastic-plastic rheologies (I2ELVIS). The devolatilized fluids are tracked via markers that are either generated or consumed based on P-T conditions. The fluids are also allowed to freely advect within the velocity field. The hosts for CO2 in this system are computed via GLOSS average sediments (H2O: 7.29 wt% & CO2: 3.01 wt%), metabasalts ( H2O: 2.63 & CO2: 2.90 wt%), and ophicarbonates (H2O: 1.98 wt% & CO2: 5.00 wt%). Our results demonstrate the feasibility of applying this decarbonation-carbonation numerical method to a range of geodynamic scenarios that simulate the removal of CO2 from the subducting slab. Such applicable scenarios include sediment diapirism into the convecting wedge and better

  17. EQUILIBRIUM CONDITION OF RESIDUAL EDGE WEDGE-TYPE NANOTWIN IN POST-DEFORMED SOLID BODY

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    Yu. V. Vasilevich

    2017-01-01

    Full Text Available An equilibrium condition of residual edge wedge-type nanotwin in a deformed solid body has been derived in the paper. The condition conclusion is based on the necessity to ensure an equilibrium of force balance acting on every twinning dislocation from the side of the rest twin dislocations. In this case dislocation structure and stress condition at nanotwin mouth have not been taken into account. Results of dislocation theory obtained in the framework of elasticity theory and continuum mechanics have been used in the paper. The paper has considered a component of the resultant force acting in a twinning plane under an assumption that there is no motion of twinning dislocations in the direction which is perpendicular to the twinning plane. The following condition has been made in the model: a discrete distribution of twinning dislocations at twin boundaries. In order to reduce cumbersome calculations a limited number of twinning dislocations has been considered in the paper and an assumption has been made about small value of a helical component in the Burgers vector, in other words the paper has considered an edge nanotwin. In order to decrease a number of equations in the system of equilibrium conditions a symmetric property of a shear component in a stress tensor has been used in the paper. The paper contains description how restrictions on the order of twinning dislocation arrangement on twin boundaries have been imposed. In this case it has been assumed that an arrangement of twinning dislocation pairs in different twin boundaries is in one plane which is perpendicular to the twinning plane. It is necessary to keep in mind that only one twinning dislocation can be located in one twinning plane. Calculations have shown that it is possible to ensure a stable and unstable equilibrium of an edge nanotwin in an ideal unloaded crystal. Sustainable balance is provided by alignment of twinning dislocations in a wall. This leads to a twin

  18. Holocene ice-wedge polygon development in northern Yukon permafrost peatlands (Canada)

    Science.gov (United States)

    Fritz, Michael; Wolter, Juliane; Rudaya, Natalia; Palagushkina, Olga; Nazarova, Larisa; Obu, Jaroslav; Rethemeyer, Janet; Lantuit, Hugues; Wetterich, Sebastian

    2016-09-01

    Ice-wedge polygon (IWP) peatlands in the Arctic and Subarctic are extremely vulnerable to climatic and environmental change. We present the results of a multidisciplinary paleoenvironmental study on IWPs in the northern Yukon, Canada. High-resolution laboratory analyses were carried out on a permafrost core and the overlying seasonally thawed (active) layer, from an IWP located in a drained lake basin on Herschel Island. In relation to 14 Accelerator Mass Spectrometry (AMS) radiocarbon dates spanning the last 5000 years, we report sedimentary data including grain size distribution and biogeochemical parameters (organic carbon, nitrogen, C/N ratio, δ13C), stable water isotopes (δ18O, δD), as well as fossil pollen, plant macrofossil and diatom assemblages. Three sediment units (SUs) correspond to the main stages of deposition (1) in a thermokarst lake (SU1: 4950 to 3950 cal yrs BP), (2) during transition from lacustrine to palustrine conditions after lake drainage (SU2: 3950 to 3120 cal yrs BP), and (3) in palustrine conditions of the IWP field that developed after drainage (SU3: 3120 cal yrs BP to 2012 CE). The lacustrine phase (pre 3950 cal yrs BP) is characterized by planktonic-benthic and pioneer diatom species indicating circumneutral waters, and very few plant macrofossils. The pollen record has captured a regional signal of relatively stable vegetation composition and climate for the lacustrine stage of the record until 3950 cal yrs BP. Palustrine conditions with benthic and acidophilic diatom species characterize the peaty shallow-water environments of the low-centered IWP. The transition from lacustrine to palustrine conditions was accompanied by acidification and rapid revegetation of the lake bottom within about 100 years. Since the palustrine phase we consider the pollen record as a local vegetation proxy dominated by the plant communities growing in the IWP. Ice-wedge cracking in water-saturated sediments started immediately after lake drainage at

  19. Congenital maxillary double lip

    Directory of Open Access Journals (Sweden)

    Dinesh Singh Chauhan

    2012-01-01

    Full Text Available Double lip, also referred to as "macrocheilia," is a rare anomaly which affects the upper lip more commonly than the lower lip. It consists of a fold of excess or redundant hypertrophic tissue on the mucosal side of the lip. The congenital double lip is believed to be present at birth and becomes more prominent after eruption of teeth. It affects esthetics and also interferes with speech and mastication. Simple surgical excision produces good functional and cosmetic results. We report a case of a non-syndromic congenital maxillary double lip in a 21-year-old male patient.

  20. A low noise front end electronics for micro-channel plate detector with wedge and strip anode

    Science.gov (United States)

    Hu, K.; Li, F.; Liang, F.; Chen, L.; Jin, G.

    2016-03-01

    A low noise Front End Electronics (FEE) for two-dimensional position sensitive Micro-Channel Plate (MCP) detector has been developed. The MCP detector is based on Wedge and Strip Anode (WSA) with induction readout mode. The WSA has three electrodes, the wedge electrode, the strip electrode, and the zigzag electrode. Then, three readout channels are designed in the Printed Circuit Board (PCB). The FEE is calibrated by a pulse generator from Agilent. We also give an analysis of the charge loss from the CSA. The noise levels of the three channels are less than 1 fC RMS at the shaping time of 200 ns. The experimental result shows that the position resolution of the MCP detector coupled with the designed PCB can reach up to 110 μm.

  1. Numerical simulations of an ocean/continent convergent system: influence of subduction geometry and mantle wedge hydration on crustal recycling

    CERN Document Server

    Roda, Manuel; Spalla, Maria Iole; 10.1029/2009GC003015

    2011-01-01

    The effects of the hydration mechanism on continental crust recycling are analyzed through a 2D finite element thermo-mechanical model. Oceanic slab dehydration and consequent mantle wedge hydration are implemented using a dynamic method. Hydration is accomplished by lawsonite and serpentine breakdown; topography is treated as a free surface. Subduction rates of 1, 3, 5, 7.5 and 10 cm/y, slab angles of 30o, 45o and 60o and a mantle rheology represented by dry dunite and dry olivine flow laws, have been taken into account during successive numerical experiments. Model predictions pointed out that a direct relationship exists between mantle rheology and the amount of recycled crustal material: the larger the viscosity contrast between hydrated and dry mantle, the larger the percentage of recycled material into the mantle wedge. Slab dip variation has a moderate impact on the recycling. Metamorphic evolution of recycled material is influenced by subduction style. TPmax, generally representative of eclogite facie...

  2. Mixed Convection Flow of Magnetic Viscoelastic Polymer from a Nonisothermal Wedge with Biot Number Effects

    Directory of Open Access Journals (Sweden)

    S. Abdul Gaffar

    2015-01-01

    Full Text Available Magnetic polymers are finding increasing applications in diverse fields of chemical and mechanical engineering. In this paper, we investigate the nonlinear steady boundary layer flow and heat transfer of such fluids from a nonisothermal wedge. The incompressible Eyring-Powell non-Newtonian fluid model is employed and a magnetohydrodynamic body force is included in the simulation. The transformed conservation equations are solved numerically subject to physically appropriate boundary conditions using a second-order accurate implicit finite difference Keller Box technique. The numerical code is validated with previous studies. The influence of a number of emerging nondimensional parameters, namely, the Eyring-Powell rheological fluid parameter (ε, local non-Newtonian parameter based on length scale (δ, Prandtl number (Pr, Biot number (γ, pressure gradient parameter (m, magnetic parameter (M, mixed convection parameter (λ, and dimensionless tangential coordinate (ξ, on velocity and temperature evolution in the boundary layer regime is examined in detail. Furthermore, the effects of these parameters on surface heat transfer rate and local skin friction are also investigated.

  3. Distal femoral opening-wedge osteotomy for lateral compartment osteoarthritis of the knee

    Directory of Open Access Journals (Sweden)

    Dirk HPW Das

    2008-11-01

    Full Text Available Dirk HPW Das1, Thea Sijbesma2, Henk J Hoekstra2, Willem M van Leeuwen21Department of Orthopaedics and Traumatology, Máxima Medisch Centrum Veldhoven, The Netherlands; 2Department of Orthopaedic Surgery, The St Anna Hospital, Geldrop, The NetherlandsAbstract: We retrospectively evaluated 12 patients with lateral gonarthritis after a distal femoral lateral opening osteotomy using a Puddu-plate. Thirteen patients with lateral gonarthritis and genu valgum were operated upon. One patient died during follow-up. We used the Lysholm score and the adapted Hospital for Special Surgery (HSS clinical and functional score. At 34 months follow up, all patients had a functional and clinical evaluation. All patients responded to a questionnaire over the telephone regarding the survival, Lysholm, and functional HSS score at 74 months follow-up. The average age at operation was 52 years. The average correction angle was 11° (16° to 5°. At 34 months follow up, the functional HSS score improved from 58 to 72 points. At 74 months follow up, the Lysholm score improved from 64 to 77 points. The clinical horizon scanning system score improved from 42 points presurgery to 64 postsurgery. Two knees were converted to total knee arthroplasty due to persisting postoperative pain. Lateral supracondylar opening-wedge osteotomy is a satisfying treatment for lateral osteoarthritis of the knee with genu valgum in younger patients.Keywords: lateral gonarthritis, femoral osteotomy, Lysholm score, knee

  4. A wedge strategy for mitigation of urban warming in future climate scenarios

    Directory of Open Access Journals (Sweden)

    L. Zhao

    2017-07-01

    Full Text Available Heat stress is one of the most severe climate threats to human society in a future warmer world. The situation is further exacerbated in urban areas by urban heat islands (UHIs. Because the majority of world's population is projected to live in cities, there is a pressing need to find effective solutions for the heat stress problem. We use a climate model to investigate the effectiveness of various urban heat mitigation strategies: cool roofs, street vegetation, green roofs, and reflective pavement. Our results show that by adopting highly reflective roofs, almost all the cities in the United States and southern Canada are transformed into white oases – cold islands caused by cool roofs at midday, with an average oasis effect of −3.4 K in the summer for the period 2071–2100, which offsets approximately 80 % of the greenhouse gas (GHG warming projected for the same period under the RCP4.5 scenario. A UHI mitigation wedge consisting of cool roofs, street vegetation, and reflective pavement has the potential to eliminate the daytime UHI plus the GHG warming.

  5. A two-dimensional model of the methane cycle in a sedimentary accretionary wedge

    Directory of Open Access Journals (Sweden)

    D. E. Archer

    2012-08-01

    Full Text Available A two-dimensional model of sediment column geophysics and geochemistry has been adapted to the problem of an accretionary wedge formation, patterned after the margin of the Juan de Fuca plate as it subducts under the North American plate. Much of the model description is given in a companion paper about the application of the model to an idealized passive margin setting; here we build on that formulation to simulate the impact of the sediment deformation, as it approaches the subduction zone, on the methane cycle. The active margin configuration of the model shares sensitivities with the passive margin configuration, in that sensitivities to organic carbon deposition and respiration kinetics, and to vertical bubble transport and redissolution in the sediment, are stronger than the sensitivity to ocean temperature. The active margin simulation shows a complex sensitivity of hydrate inventory to plate subduction velocity, with results depending strongly on the geothermal heat flux. In low heat-flux conditions, the model produces a larger inventory of hydrate per meter of coastline in the passive margin than active margin configurations. However, the local hydrate concentrations, as pore volume saturation, are higher in the active setting than in the passive, as generally observed in the field.

  6. Stationary bubble formation and cavity collapse in wedge-shaped hoppers

    CERN Document Server

    Yagisawa, Yui; Okumura, Ko

    2016-01-01

    The hourglass is one of the apparatuses familiar to everyone, but reveals intriguing behaviors peculiar to granular materials, and many issues are remained to be explored. In this study, we examined the dynamics of falling sand in a special form of hourglass, i.e., a wedge-shaped hopper, when a suspended granular layer is stabilized to a certain degree. As a result, we found remarkably different dynamics, bubbling and cavity regimes. In the bubbling regime, bubbles of nearly equal size are created in the sand at a regular time interval. In the cavity regime, a cavity grows as sand beads fall before a sudden collapse of the cavity. Bubbling found here is quite visible to a level never discussed in the physics literature and the cavity regime is a novel phase, which is neither continuous, intermittent nor completely blocked phase. We elucidate the physical conditions necessary for the bubbling and cavity regimes and develop simple theories for the regimes to successfully explain the observed phenomena by consid...

  7. Seismic evidence for flow in the hydrated mantle wedge of the Ryukyu subduction zone.

    Science.gov (United States)

    Nagaya, Takayoshi; Walker, Andrew M; Wookey, James; Wallis, Simon R; Ishii, Kazuhiko; Kendall, J-Michael

    2016-07-20

    It is widely accepted that water-rich serpentinite domains are commonly present in the mantle above shallow subducting slabs and play key roles in controlling the geochemical cycling and physical properties of subduction zones. Thermal and petrological models show the dominant serpentine mineral is antigorite. However, there is no good consensus on the amount, distribution and alignment of this mineral. Seismic velocities are commonly used to identify antigorite-rich domains, but antigorite is highly-anisotropic and depending on the seismic ray path, its properties can be very difficult to distinguish from non-hydrated olivine-rich mantle. Here, we utilize this anisotropy and show how an analysis of seismic anisotropy that incorporates measured ray path geometries in the Ryukyu arc can constrain the distribution, orientation and amount of antigorite. We find more than 54% of the wedge must consist of antigorite and the alignment must change from vertically aligned to parallel to the slab. This orientation change suggests convective flow in the hydrated forearc mantle. Shear wave splitting analysis in other subduction zones indicates large-scale serpentinization and forearc mantle convection are likely to be more widespread than generally recognized. The view that the forearc mantle of cold subduction zones is dry needs to be reassessed.

  8. Global typology of urban energy use and potentials for an urbanization mitigation wedge.

    Science.gov (United States)

    Creutzig, Felix; Baiocchi, Giovanni; Bierkandt, Robert; Pichler, Peter-Paul; Seto, Karen C

    2015-05-19

    The aggregate potential for urban mitigation of global climate change is insufficiently understood. Our analysis, using a dataset of 274 cities representing all city sizes and regions worldwide, demonstrates that economic activity, transport costs, geographic factors, and urban form explain 37% of urban direct energy use and 88% of urban transport energy use. If current trends in urban expansion continue, urban energy use will increase more than threefold, from 240 EJ in 2005 to 730 EJ in 2050. Our model shows that urban planning and transport policies can limit the future increase in urban energy use to 540 EJ in 2050 and contribute to mitigating climate change. However, effective policies for reducing urban greenhouse gas emissions differ with city type. The results show that, for affluent and mature cities, higher gasoline prices combined with compact urban form can result in savings in both residential and transport energy use. In contrast, for developing-country cities with emerging or nascent infrastructures, compact urban form, and transport planning can encourage higher population densities and subsequently avoid lock-in of high carbon emission patterns for travel. The results underscore a significant potential urbanization wedge for reducing energy use in rapidly urbanizing Asia, Africa, and the Middle East.

  9. A wedge strategy for mitigation of urban warming in future climate scenarios

    Science.gov (United States)

    Zhao, Lei; Lee, Xuhui; Schultz, Natalie M.

    2017-07-01

    Heat stress is one of the most severe climate threats to human society in a future warmer world. The situation is further exacerbated in urban areas by urban heat islands (UHIs). Because the majority of world's population is projected to live in cities, there is a pressing need to find effective solutions for the heat stress problem. We use a climate model to investigate the effectiveness of various urban heat mitigation strategies: cool roofs, street vegetation, green roofs, and reflective pavement. Our results show that by adopting highly reflective roofs, almost all the cities in the United States and southern Canada are transformed into white oases - cold islands caused by cool roofs at midday, with an average oasis effect of -3.4 K in the summer for the period 2071-2100, which offsets approximately 80 % of the greenhouse gas (GHG) warming projected for the same period under the RCP4.5 scenario. A UHI mitigation wedge consisting of cool roofs, street vegetation, and reflective pavement has the potential to eliminate the daytime UHI plus the GHG warming.

  10. Solving Large-Scale TSP Using a Fast Wedging Insertion Partitioning Approach

    Directory of Open Access Journals (Sweden)

    Zuoyong Xiang

    2015-01-01

    Full Text Available A new partitioning method, called Wedging Insertion, is proposed for solving large-scale symmetric Traveling Salesman Problem (TSP. The idea of our proposed algorithm is to cut a TSP tour into four segments by nodes’ coordinate (not by rectangle, such as Strip, FRP, and Karp. Each node is located in one of their segments, which excludes four particular nodes, and each segment does not twist with other segments. After the partitioning process, this algorithm utilizes traditional construction method, that is, the insertion method, for each segment to improve the quality of tour, and then connects the starting node and the ending node of each segment to obtain the complete tour. In order to test the performance of our proposed algorithm, we conduct the experiments on various TSPLIB instances. The experimental results show that our proposed algorithm in this paper is more efficient for solving large-scale TSPs. Specifically, our approach is able to obviously reduce the time complexity for running the algorithm; meanwhile, it will lose only about 10% of the algorithm’s performance.

  11. Salt wedge determination using electrical sounding method in the region of Oued Nador (Tipaza, Algeria)

    Science.gov (United States)

    Amine Bechkit, Mohamed; Benaïssa, Zahia; Ouadfeul, Sid Ali; Deghmoum, Feriel

    2017-04-01

    The marine intrusion of freshwater aquifers by salt water results in soil degradation due to their salinization. The present survey aims to study the position of the fresh water - salt water interface using electric sounding method in the region of Oued Nador (Tipaza, Algeria). It is important to know the position of this interface for the continuation of the aquifer exploitation. For this, we conducted, in this zone, seven electric soundings oriented north-west south-east, with Schlumberger electrodes configuration. The inversion of the apparent resistivity data via the IP2Win software allowed us to recover the true values of electrical resistivity. The exploitation of obtained data requires the implementation of a geo-electric section, and for the interpretation, the results of a standard electrical sounding, acquired near the study area, are used. The results of this geophysical study allowed us to locate the freshwater - salt water contact with resistivity values that can reach 50 ohm m for freshwater formation, and less than 10 ohm m for saturated saltwater formation. The depth of the contact between fresh water and salt water increases gradually from 38 m to 40 m near the coast, and this over a distance of 0 m to 500 m, and then rises abruptly beyond a distance of 500 m at the borehole N°3 where it reaches the maximum depth of 97 m. Key words: Electrical survey - Salt wedge - Electrical resistivity - Aquifer - Intrusion.

  12. Open-Wedge High Tibial Osteotomy: RCT 2 Years RSA Follow-Up.

    Science.gov (United States)

    Lind-Hansen, Thomas Bruno; Lind, Martin Carøe; Nielsen, Poul Torben; Laursen, Mogens Berg

    2016-11-01

    We investigated the influence of three different bone grafting materials on stability and clinical outcome of the healing open-wedge high tibial osteotomy (OW-HTO) with immediate partial weight bearing. A total of 45 (3 × 15) patients were randomized to injectable calcium phosphate cement (Calcibon; Biomet-Merck Biomaterials GmbH, Darmstadt, Germany), local bone autograft, or iliac crest autograft. Stability of the bony healing was evaluated with radiostereometric analysis (RSA) up to 24 months postoperatively. Clinical outcome was evaluated with the knee injury and osteoarthritis outcome score (KOOS). RSA revealed translations and rotations close to zero regardless of bone grafting material, with no statistically significant differences between the groups. Clinically, the Calcibon group had lower quality of life KOOS subscore at 2 years follow-up. We conclude that with a stable implant and 6 weeks of partial weight bearing, local autografting is sufficient to achieve solid bone consolidation following OW-HTO. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  13. Turbulent transport coefficients in spherical wedge dynamo simulations of solar-like stars

    Science.gov (United States)

    Warnecke, J.; Rheinhardt, M.; Tuomisto, S.; Käpylä, P. J.; Käpylä, M. J.; Brandenburg, A.

    2018-01-01

    Aims: We investigate dynamo action in global compressible solar-like convective dynamos in the framework of mean-field theory. Methods: We simulate a solar-type star in a wedge-shaped spherical shell, where the interplay between convection and rotation self-consistently drives a large-scale dynamo. To analyze the dynamo mechanism we apply the test-field method for azimuthally (φ) averaged fields to determine the 27 turbulent transport coefficients of the electromotive force, of which six are related to the α tensor. This method has previously been used either in simulations in Cartesian coordinates or in the geodynamo context and is applied here for the first time to fully compressible simulations of solar-like dynamos. Results: We find that the φφ-component of the α tensor does not follow the profile expected from that of kinetic helicity. The turbulent pumping velocities significantly alter the effective mean flows acting on the magnetic field and therefore challenge the flux transport dynamo concept. All coefficients are significantly affected by dynamically important magnetic fields. Quenching as well as enhancement are being observed. This leads to a modulation of the coefficients with the activity cycle. The temporal variations are found to be comparable to the time-averaged values and seem to be responsible for a nonlinear feedback on the magnetic field generation. Furthermore, we quantify the validity of the Parker-Yoshimura rule for the equatorward propagation of the mean magnetic field in the present case.

  14. Clinical Efficacy of an Arthroscopic Surgery in Open Wedge High Tibial Osteotomy.

    Science.gov (United States)

    Kim, Chang-Wan; Lee, Chang-Rack; Seo, Seung-Suk; Gwak, Heui-Chul; Kim, Jung-Han; Jeong, Jun-Woo

    2017-05-01

    Few studies have identified the effects of arthroscopic surgery on the clinical outcomes when open wedge high tibial osteotomy (OWHTO) and arthroscopic surgery were performed together. The purpose of this study was to evaluate the clinical efficacy of arthroscopic surgery in patients who had varus osteoarthritic knee and were treated with OWHTO combined with arthroscopic surgery. Among the 98 knees (88 patients) who underwent OWHTO between January 2008 and March 2013, 79 knees (71 patients) with more than 2 years of follow-up were reviewed retrospectively. The patients were divided into two groups: Group 1 (24 knees) underwent only OWHTO and Group 2 (55 knees) underwent OWHTO combined with arthroscopic surgery. For clinical evaluation, the range of motion (ROM), pain visual analog scale, Knee Society knee score, Knee Society function score, and complication were used. For radiologic evaluation, Kellgren-Lawrence grade, mechanical femorotibial angle, and posterior tibial slope were used. The average follow-up period was 29.1 months. Group 2 showed a significant increase in the ROM at the last follow-up (133.2  ± 6.0 degrees) compared with the preoperative time point (128.3 ± 7.7 degrees) (p arthroscopic surgery was performed, arthroscopic surgery helped increase the ROM of patients with mechanical symptoms. However, the amount of the ROM increase of 4.9 degrees was of unknown clinical significance. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  15. A novel and fast method for proton range verification using a step wedge and 2D scintillator.

    Science.gov (United States)

    Shen, Jiajian; Allred, Bryce C; Robertson, Daniel G; Liu, Wei; Sio, Terence T; Remmes, Nicholas B; Keole, Sameer R; Bues, Martin

    2017-09-01

    To implement and evaluate a novel and fast method for proton range verification by using a planar scintillator and step wedge. A homogenous proton pencil beam plan with 35 energies was designed and delivered to a 2D flat scintillator with a step wedge. The measurement was repeated 15 times (3 different days, 5 times per day). The scintillator image was smoothed, the Bragg peak and distal fall off regions were fitted by an analytical equation, and the proton range was calculated using simple trigonometry. The accuracy of this method was verified by comparing the measured ranges to those obtained using an ionization chamber and a scanning water tank, the gold standard. The reproducibility was evaluated by comparing the ranges over 15 repeated measurements. The sensitivity was evaluated by delivering to same beam to the system with a film inserted under the wedge. The range accuracy of all 35 proton energies measured over 3 days was within 0.2 mm. The reproducibility in 15 repeated measurements for all 35 proton ranges was ±0.045 mm. The sensitivity to range variation is 0.1 mm for the worst case. This efficient procedure permits measurement of 35 proton ranges in less than 3 min. The automated data processing produces results immediately. The setup of this system took less than 5 min. The time saving by this new method is about two orders of magnitude when compared with the time for water tank range measurements. A novel method using a scintillator with a step wedge to measure the proton range was implemented and evaluated. This novel method is fast and sensitive, and the proton range measured by this method was accurate and highly reproducible. © 2017 American Association of Physicists in Medicine.

  16. Two-parameter fracture mechanical analysis of a near-crack-tip stress field in wedge splitting test specimens

    Czech Academy of Sciences Publication Activity Database

    Seitl, Stanislav; Veselý, V.; Řoutil, L.

    2011-01-01

    Roč. 89, 21-22 (2011), s. 1852-1858 ISSN 0045-7949. [International Conference on Civil, Structural and Enviromental Engineering Computing /12./. Funchal, Madeira, 01.09.2009-04.09.2009] Institutional research plan: CEZ:AV0Z20410507 Keywords : Wedge splitting test * Stress intensity factor * T-stress * Numerical simulation * Direct method Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 1.874, year: 2011

  17. Draft Genome Sequence of Tomitella biformata AHU 1821T, Isolated from a Permafrost Ice Wedge in Alaska.

    Science.gov (United States)

    Funo, Kentaro; Kitagawa, Wataru; Tanaka, Michiko; Sone, Teruo; Asano, Kozo; Kamagata, Yoichi

    2014-02-13

    Tomitella biformata AHU 1821(T) was isolated and cultured from a permafrost ice wedge, aged presumably about 25,000 years, in the Fox permafrost tunnel (64.952°N 147.617°W), Alaska. These genome data provide the basis for investigating T. biformata AHU 1821(T), identified as a long-term survivor of the extremely cold and closed environment.

  18. Draft Genome Sequence of Tomitella biformata AHU 1821T, Isolated from a Permafrost Ice Wedge in Alaska

    OpenAIRE

    Funo, Kentaro; Kitagawa, Wataru; Tanaka, Michiko; Sone, Teruo; Asano, Kozo; Kamagata, Yoichi

    2014-01-01

    Tomitella biformata AHU 1821T was isolated and cultured from a permafrost ice wedge, aged presumably about 25,000 years, in the Fox permafrost tunnel (64.952°N 147.617°W), Alaska. These genome data provide the basis for investigating T. biformata AHU 1821T, identified as a long-term survivor of the extremely cold and closed environment.

  19. Grid generation and adaptation for the Direct Simulation Monte Carlo Method. [for complex flows past wedges and cones

    Science.gov (United States)

    Olynick, David P.; Hassan, H. A.; Moss, James N.

    1988-01-01

    A grid generation and adaptation procedure based on the method of transfinite interpolation is incorporated into the Direct Simulation Monte Carlo Method of Bird. In addition, time is advanced based on a local criterion. The resulting procedure is used to calculate steady flows past wedges and cones. Five chemical species are considered. In general, the modifications result in a reduced computational effort. Moreover, preliminary results suggest that the simulation method is time step dependent if requirements on cell sizes are not met.

  20. The lug with wedges re-launches the electric braking; L'etrier a coins relance le freinage electrique

    Energy Technology Data Exchange (ETDEWEB)

    Dumas, A.

    2005-10-01

    Electric-powered braking systems are lighter than hydraulic ones but require lot of energy. A system developed by Siemens VDO, named EWB (electronic wedge brake) uses the kinetic energy of the wheel to mechanically move the brake blocks aside and press the pads against the disc. Electric motors are used to move the blocks tangentially and start-up the braking but the main part of the braking energy comes from the system itself. Short paper. (J.S.)

  1. Thermal erosion of ice-wedge polygon terrains changes fluxes of energy and matter of permafrost geosystems

    Science.gov (United States)

    Fortier, D.; Godin, E.; Lévesque, E.; Veillette, A.; Lamarque, L.

    2015-12-01

    Subsurface thermal erosion is triggered by convective heat transfers between flowing water and permafrost. Heat advection due to infiltration of run-off in the massive ice wedges and the ice-rich upper portion of permafrost creates sink holes and networks of interconnected tunnels in the permafrost. Mass movements such as collapse of tunnel's roof, retrogressive thaw-slumping and active layer detachment slides lead to the development of extensive gully networks in the landscape. These gullies drastically change the hydrology of ice-wedge polygon terrains and the fluxes of heat, water, sediment, nutrients and carbon within the geosystem. Exportation of sediments out of gullies are positive mechanical feed-back that keep channels active for decades. Along gully margins, drainage of disturbed polygons and ponds, slope drainage, soil consolidation, gully walls colonization by vegetation and wet to mesic plant succession change the thermal properties of the active layer and create negative feedback effects that stabilize active erosion processes and promote permafrost recovery in gully slopes and adjacent disturbed polygons. On Bylot Island (Nunavut), over 40 gullies were monitored to characterize gully geomorphology, thermal and mechanical processes of gully erosion, rates of gully erosion over time within different sedimentary deposits, total volume of eroded permafrost at the landscape scale and gully hydrology. We conducted field and laboratory experiments to quantify heat convection processes and speed of ice wedge ablation in order to derive empirical equations to develop model of permafrost thermal erosion. We used data, collected over 10 years, of geomorphological gully monitoring and regional climate scenarios to evaluate the potential response of ice-wedge polygon terrains to changes in snow, permafrost thermal regime and hydrological conditions over the coming decades and its implication for the short and long term dynamics of arctic permafrost geosystems.

  2. Comparison of Foraging Behaviors and Movement Patterns of the Wedge-Billed Woodcreeper (Glyphorynchus spirurus) Traveling Alone and in Mixed-Species Flocks in Amazonian Ecuador

    National Research Council Canada - National Science Library

    Abigail J. Darrah; Kimberly G. Smith

    2013-01-01

    ... to flock movement patterns. We compared the foraging behavior and microhabitat use of Wedge-billed Woodcreepers in and out of flocks at Tiputini Biodiversity Station, eastern Ecuador, during January–March, 2010–2012...

  3. Calculation of exit dose for conformal and dynamically‐wedged fields, based on water‐equivalent path length measured with an amorphous silicon electronic portal imaging device

    National Research Council Canada - National Science Library

    Kavuma, Awusi; Glegg, Martin; Metwaly, Mohamed; Currie, Garry; Elliott, Alex

    2011-01-01

    ...) and, therefore, exit doses, so as to model doses in conformal and enhanced dynamic wedge (EDW) fields. The QCM involves acquiring series of EPID images at a reference field size for different thicknesses of homogeneous solid water blocks...

  4. Calculation of exit dose for conformal and dynamically-wedged fields, based on water-equivalent path length measured with an amorphous silicon electronic portal imaging device

    National Research Council Canada - National Science Library

    Kavuma, Awusi; Glegg, Martin; Metwaly, Mohamed; Currie, Garry; Elliott, Alex

    2011-01-01

    ...) and, therefore, exit doses, so as to model doses in conformal and enhanced dynamic wedge (EDW) fields. The QCM involves acquiring series of EPID images at a reference field size for different thicknesses of homogeneous solid water blocks...

  5. A developed wedge fixtures assisted high precision TEM samples pre-thinning method: Towards the batch lamella preparation

    Science.gov (United States)

    Wang, Dandan; Huang, Yamin; Liu, Binghai; Zhu, Lei; Lam, Jeffrey; Mai, Zhihong

    2017-04-01

    Ion milling, wedge cutting or polishing, and focused ion beam (FIB) milling are widely-used techniques for the transmission electron microscope (TEM) sample preparation. Especially, the FIB milling provides a site-specific analysis, deposition, and ablation of materials in the micrometer and nanometer scale. However, the cost of FIB tools has been always a significant concern. Since it is inevitable to use the FIB technique, the improvement of efficiency is a key point. Traditional TEM sample preparation with FIB was routinely implemented on a single sample each time. Aiming at cost efficiency, a new pre-thinning technique for batch sample preparation was developed in this paper. The present proposal combines the sample preparation techniques with multi-samples thinning, cross-section scanning electron microscopy (SEM), wedge cutting, FIB and other sample pre-thinning techniques. The new pre-thinning technique is to prepare an edge TEM sample on a grinding and polishing fixture with a slant surface. The thickness of the wedges sample can be measured to 1˜2 μm under optical microscope. Therefore, this fixture is superior to the traditional optical method of estimating the membrane thickness. Moreover, by utilizing a multi-sample holding fixture, more samples can be pre-thinned simultaneously, which significantly improved the productivity of TEM sample preparation.

  6. Total knee arthroplasty conversion after a failed lateral closing wedge high tibial osteotomy with knee hyperextension and secondary ankle degeneration

    Science.gov (United States)

    Yao, Chen; Xu, Xingquan; Zhou, Sheng; Song, Xiaoxiao; Shi, Dongquan; Jiang, Qing

    2017-01-01

    Abstract Rationale: High tibial osteotomy (HTO) has been used widely for medial compartment knee osteoarthritis to correct the deformity and relieve symptoms, especially in young patients who are willing to maintain the high activity level. However, the change of bone morphology, ligament imbalance, limb malalignment, and other complications may influence the short-term outcomes of HTO. Some cases may even require conversion to TKA shortly after HTO because of the loss of correction or pain due to accelerated osteoarthritis. Patient concerns: A 43-year-old female patient presented with persistent pain of both the left knee and the ankle. She underwent a lateral closing wedge HTO two years ago. Radiographies showed The Kellgren-Lawrence (K-L) grade IV osteoarthritic change and hyperextension (HE) of the left knee and the degeneration of the left ankle. Diagnoses: A failed lateral closing wedge high tibial osteotomy with knee hyperextension and secondary ankle degeneration. Intervention: A posterior-stabilized TKA conversion and postoperative rehabilitation were performed. Outcomes: The operation corrected the HE deformity and relieved the pain at the level of the left knee. However, the secondary change of the left ankle was irreversible. Lessons: A failed lateral closing wedge HTO might speed up the degeneration of the knee and increase extra technical issues in the following TKA. What is more, the secondary osteoarthritis and deformity of the ankle cannot be ignored. PMID:28723758

  7. A developed wedge fixtures assisted high precision TEM samples pre-thinning method: Towards the batch lamella preparation

    Directory of Open Access Journals (Sweden)

    Dandan Wang

    2017-04-01

    Full Text Available Ion milling, wedge cutting or polishing, and focused ion beam (FIB milling are widely-used techniques for the transmission electron microscope (TEM sample preparation. Especially, the FIB milling provides a site-specific analysis, deposition, and ablation of materials in the micrometer and nanometer scale. However, the cost of FIB tools has been always a significant concern. Since it is inevitable to use the FIB technique, the improvement of efficiency is a key point. Traditional TEM sample preparation with FIB was routinely implemented on a single sample each time. Aiming at cost efficiency, a new pre-thinning technique for batch sample preparation was developed in this paper. The present proposal combines the sample preparation techniques with multi-samples thinning, cross-section scanning electron microscopy (SEM, wedge cutting, FIB and other sample pre-thinning techniques. The new pre-thinning technique is to prepare an edge TEM sample on a grinding and polishing fixture with a slant surface. The thickness of the wedges sample can be measured to 1∼2 μm under optical microscope. Therefore, this fixture is superior to the traditional optical method of estimating the membrane thickness. Moreover, by utilizing a multi-sample holding fixture, more samples can be pre-thinned simultaneously, which significantly improved the productivity of TEM sample preparation.

  8. A microfabricated wedge-shaped adhesive array displaying gecko-like dynamic adhesion, directionality and long lifetime.

    Science.gov (United States)

    Parness, Aaron; Soto, Daniel; Esparza, Noé; Gravish, Nick; Wilkinson, Matt; Autumn, Kellar; Cutkosky, Mark

    2009-12-06

    Gecko adhesion has become a paradigmatic example of bio-inspired engineering, yet among the many gecko-like synthetic adhesives (GSAs), truly gecko-like performance remains elusive. Many GSAs have previously demonstrated one or two features of the gecko adhesive. We present a new wedge-shaped GSA that exhibits several gecko-like properties simultaneously: directional features; zero force at detachment; high ratio of detachment force to preload force; non-adhesive default state; and the ability to maintain performance while sliding, even after thousands of cycles. Individual wedges independently detach and reattach during sliding, resulting in high levels of shear and normal adhesion during drag. This behaviour provides a non-catastrophic failure mechanism that is desirable for applications such as climbing robots where sudden contact failure would result in serious falls. The effects of scaling patch sizes up to tens of square centimetres are also presented and discussed. Patches of 1 cm(2) had an adhesive pressure of 5.1 kPa while simultaneously supporting 17.0 kPa of shear. After 30 000 attachment/detachment cycles, a patch retained 67 per cent of its initial adhesion and 76 per cent of its initial shear without cleaning. Square-based wedges of 20 mum and 50 mum are manufactured in a moulding process where moulds are fabricated using a dual-side, dual-angle lithography process on quartz wafers with SU-8 photoresist as the mould material and polydimethylsiloxane as the cast material.

  9. Numerical And Experimental Study On Producing Aluminum Alloy 6061 Shafts By Cross Wedge Rolling Using A Universal Rolling Mill

    Directory of Open Access Journals (Sweden)

    Tofil A.

    2015-06-01

    Full Text Available The paper presents a selection of numerical and theoretical results of the cross wedge rolling process for producing stepped shafts made of aluminum alloy 6061. The numerical modeling was performed using the FEM-based Simufact Forming simulation software. In the simulations, we examined the kinematics of metal flow and determined the distribution patterns of effective strains, temperatures, axial stresses and the Cockroft-Latham damage criterion. Variations in the rolling forces were determined, too. The numerical results were verified experimentally using a universal rolling mill designed and constructed by the present authors. This machine can be used to perform such processes as cross wedge rolling, longitudinal rolling and round bar cropping. During the experiments, we examined process stability and finished product geometry and recorded the torques. The experimental results confirm that axisymmetric aluminum alloy shafts can be produced by cross wedge rolling with two rolls. Last but not least, the experiments served to evaluate the technological potential of the rolling mill used.

  10. Formation of Double Neutron Stars, Millisecond Pulsars and Double ...

    Indian Academy of Sciences (India)

    Edward P. J. Heuvel

    2017-09-12

    Sep 12, 2017 ... the double neutron stars and of double black holes is given. 2. Double neutron stars and millisecond pulsars. 2.1 Double neutron stars. In the period 1978 to 1980, Srinivasan and van den. Heuvel profoundly discussed the possible ways in which the Hulse–Taylor binary pulsar could have been formed.

  11. Effects of two different degrees of lateral-wedge insoles on unilateral lower extremity load-bearing line in patients with medial knee osteoarthritis.

    Science.gov (United States)

    Yılmaz, Bilge; Kesikburun, Serdar; Köroğlu, Ozlem; Yaşar, Evren; Göktepe, Ahmet Salim; Yazıcıoğlu, Kamil

    2016-08-01

    The aim of this study is to assess the effect of 5 and 10° lateral-wedge insoles on unilateral lower extremity load carrying line in patients with medial knee osteoarthritis using the L.A.S.A.R. posture alignment system. Twenty subjects (10 females and 10 males, mean age 67.7 ± 5.4 years (range: 58-78) with bilateral medial knee osteoarthritis were included in the study. The laser line projected on the person by the L.A.S.A.R. posture alignment system showed joint load carrying line. The location of the joint load carrying line in static standing with one foot on the force plate was assessed with barefoot, and 5° and 10° lateral-wedge insoles. Displacement of the load carrying line was measured using a ruler placed tangentially to the patella at the level of joint line. The load carrying lines measured with 5° and 10° lateral-wedge insoles were significantly laterally located compared to that without wearing insole (p lateral-wedge insole caused a significant more lateral shifting of the load carrying line than 5° lateral-wedge insole (p line to the lateral. Lateral wedged insoles are biomechanically effective and reduce loading of the medial compartment in patients with medial knee osteoarthritis. Copyright © 2016 Turkish Association of Orthopaedics and Traumatology. Production and hosting by Elsevier B.V. All rights reserved.

  12. Open wedge metatarsal osteotomy versus crescentic osteotomy to correct severe hallux valgus deformity - A prospective comparative study.

    Science.gov (United States)

    Wester, Jens Ulrik; Hamborg-Petersen, Ellen; Herold, Niels; Hansen, Palle Bo; Froekjaer, Johnny

    2016-03-01

    Different techniques of proximal osteotomies have been introduced to correct severe hallux valgus. The open wedge osteotomy is a newly introduced method for proximal osteotomy. The aim of this prospective randomized study was to compare the radiological and clinical results after operation for severe hallux valgus, comparing the open wedge osteotomy to the crescentic osteotomy which is our traditional treatment. Forty-five patients with severe hallux valgus (hallux valgus angle >35̊, and intermetatarsal angle >15̊) were included in this study. The treatment was proximal open wedge osteotomy and fixation with plate (Hemax), group 1, or operation with proximal crescentic osteotomy and fixation with a 3mm cannulated screw, group 2. The mean age was 52 years (19-71). Forty-one females and four males were included. Clinical and radiological follow-ups were performed 4 and 12 months after the operation. In group 1 the hallux valgus angle decreased from 39.0̊ to 24.1̊ after 4 months and 27.9̊ after 12 months. In group 2 the angle decreased from 38.3̊ to 21.4̊ after 4 months and 27.0̊ after 12 months. The intermetatarsal angle in group 1 was 19.0̊ preoperatively, 11.6̊ after 4 months and 12.6̊ after 12 months. In group 2 the mean intermetatarsal angle was 18.9̊ preoperatively, 12.0̊ after 4 months and 12.6̊ after 12 months. The AOFAS score improved from 59.3 to 81.5 in group 1 and from 61.8 to 84.8 in group 2 respectively measured 12 months postoperatively. The relative length of the 1 metatarsal compared to 2 metatarsal bone was 0.88 and 0.87 preoperatively and 0.88 and 0.86 for group 1 and 2 respectively measured after 12 months. Crescentic osteotomy and open wedge osteotomy improve AOFAS score and VAS scores on patients operated with severe hallux valgus. No significant difference was found in the two groups looking at the postoperative improvement of HVA and IMA measured 4 and 12 months postoperatively. The postoperative VAS score and AOFAS score were

  13. Computational analysis of responses of a wedge-shaped-tip optical fiber probe in bubble measurement.

    Science.gov (United States)

    Sakamoto, A; Saito, T

    2012-07-01

    Optical-fiber probing is widely employed in bubble/droplet measurement in gas-liquid two-phase flows. Several types of optical fiber probes with a very high S/N ratio and high performance have been developed, but further improvement in the probes' measurement accuracy and reliability for industrial applications is desired. We tried to eliminate optical noise in the probe measurements, and we found that the signals include some peak signs that have potential for advanced measurement with optical-fiber probing. We developed a ray-tracing numerical simulator and identified the mechanisms underlying the generation of the signals. In order to numerically simulate the optical probing signals, the simulator must use 3D frameworks composed of incident beams, the reflection and refraction on the surfaces of the optical elements (i.e., an optical fiber, a sensing tip, an air phase, and a water phase), and beams returning from the sensing tip to the other tip through the fiber. We used all of these in a simple rendering framework based on a ray-tracing algorithm with Fresnel's law, and we observed the mechanism of some promising signals that may be useful for extracting the hidden potential of optical-fiber probing. To verify the simulator's performance, we carried out three comparative experiments with fundamental setups using a wedge-shaped single-tip optical fiber probe, examining: (1) the beam trajectories and energy leaking out from the sensing tip into the surrounding air phase or water phase, (2) the probing signals throughout penetration of the sensing tip at the air-water free interface in light of the three-dimensional deformation, and (3) the probing signals throughout penetration of the sensing tip into a bubble in light of the three-dimensional bubble shape. As a result, (a) we found that an optical fiber probe with a wedge-shaped tip has particular characteristics of beam emissions from the tip, and the emitting angles switched depending on the phases covering

  14. Opening wedge high tibial osteotomy: plate position and biomechanics of the medial tibial plateau.

    Science.gov (United States)

    Martinez de Albornoz, Pilar; Leyes, Manuel; Forriol, Francisco; Del Buono, Angelo; Maffulli, Nicola

    2014-11-01

    To ascertain whether changing position and size of the spacer may modify the load and displacement of the tibial plateau when performing an opening wedge high tibial osteotomy. Fifteen sawbones tibia models were used. In the axial plane, the anterior, medial, and posterior thirds of the tibial plateau were marked, and the medial and posterior thirds were called "point 1" and "point 2", respectively. A 7.5-mm-stainless steel indenter was used to apply the load over these two points: the load applied to point 1 simulated the load to that site when the knee was extended, and the load to point 2 simulated the load to the same area when the knee was flexed. Maximum load (N) and displacement (mm) were calculated. The system was shown to withstand higher loads with less displacement when the plate was posterior than it could do with the plate in the middle position. Significant differences were also found when comparing the anterior and middle position of the plate with the greatest displacement when the plate was anterior. The differences were increased when comparing the anterior and posterior positions of the plate. No statistical differences (n.s.) were found when using different spacers. The maximum stiffness was achieved if the plate was posterior and in point 1 indenter position, in which the force vector stands on the points of the lateral and medial supports (Fμ = 198.8 ± 61.5 N). The lowest stiffness was observed when the plate was anterior, and the force was applied to point 2 (Fμ = 29.7 ± 5.1 N). Application of the plate in a more posterior position provides greater stability.

  15. Grounding-zone wedges and lateral moraines of palaeo-ice streams

    Science.gov (United States)

    Batchelor, C.; Dowdeswell, J. A.

    2016-12-01

    The landforms that are preserved at the beds of former marine-terminating ice streams provide information about ice-sheet dynamics and the processes that are operating beneath contemporary ice streams. Sedimentary landforms, including grounding-zone wedges (GZWs), can build up during still-stands or re-advances of the frontal grounding zone of ice streams. Significant sedimentary depocentres, termed ice-stream lateral moraines (ISLMs), can also be formed at ice-stream lateral margins. We present an inventory of GZWs and ISLMs that is compiled from available studies and independent analysis of seismic-reflection and swath-bathymetric data. We discuss the geomorphic and acoustic characteristics of these landforms and their implications for ice dynamics. GZWs indicate episodic ice stream retreat and probably form mainly where floating ice shelves constrain vertical accommodation space beyond the grounding zone. Many GZWs occur at vertical or lateral pinning points, where cross-shelf troughs either shallow or constrict, which encourage grounding-zone stability through increasing basal and lateral drag and reducing mass flow across the grounding zone. We identify two different types of ISLMs. Lateral shear-moraines form subglacially in the shear zone between ice streams and slower-flowing ice. They are up to 3.5 km wide and 60 m thick, and maintain a relatively constant width, thickness and cross-sectional shape along their length. Lateral marginal-moraines form at the lateral boundary between ice streams and seafloor terrain that was free of grounded ice. They are up to 50 km wide and 300 m thick, and exhibit a seaward increase in width and thickness. Lateral marginal-moraines have a similar volume and acoustic character to GZWs. However, whereas GZWs are formed by the ice-flow parallel delivery of sediment to the grounding zone, lateral marginal-moraines are produced when sediment is delivered to the ice-stream lateral margin at an oblique angle to the ice

  16. Improvement in quality of hospital care during accreditation: A nationwide stepped-wedge study.

    Science.gov (United States)

    Bogh, Søren Bie; Falstie-Jensen, Anne Mette; Hollnagel, Erik; Holst, René; Braithwaite, Jeffrey; Johnsen, Søren Paaske

    2016-12-01

    To assess changes over time in quality of hospital care in relation to the first accreditation cycle in Denmark. We performed a multi-level, longitudinal, stepped-wedge, nationwide study of process performance measures to evaluate the impact of a mandatory accreditation programme in all Danish public hospitals. Patient-level data (n = 1 624 518 processes of care) on stroke, heart failure, ulcer, diabetes, breast cancer and lung cancer care were obtained from national clinical quality registries. The Danish Healthcare Quality Programme was introduced in 2009, aiming to create a framework for continuous quality improvement. Changes in week-by-week trends of hospital care during the study period of 269 weeks prior to, during and post-accreditation. The quality of hospital care improved over time throughout the study period. The overall positive change in trend odds ratio (OR) = 1.002 per week; 95% confidence interval (CI: 0.997-1.006) observed when comparing the period during accreditation with the period prior to accreditation was not significant. However, when restricting the analyses to processes of care where the performance did not meet target values for satisfactory quality prior to accreditation, we found a significant positive change in trend (OR = 1.006 per week; 95% CI: 1.001-1.011). When comparing the post-accreditation period with the period during accreditation, we found a significantly reduced trend (OR = 0.994 per week; 95% CI: 0.988-0.999), indicating the improvement in quality of care continued but at a lower rate than during accreditation. These findings support the hypothesis that hospital accreditation leads to improvements in patient care.

  17. Predicting translational deformity following opening-wedge osteotomy for lower limb realignment.

    Science.gov (United States)

    Barksfield, Richard C; Monsell, Fergal P

    2015-11-01

    An opening-wedge osteotomy is well recognised for the management of limb deformity and requires an understanding of the principles of geometry. Translation at the osteotomy is needed when the osteotomy is performed away from the centre of rotation of angulation (CORA), but the amount of translation varies with the distance from the CORA. This translation enables proximal and distal axes on either side of the proposed osteotomy to realign. We have developed two experimental models to establish whether the amount of translation required (based on the translation deformity created) can be predicted based upon simple trigonometry. A predictive algorithm was derived where translational deformity was predicted as 2(tan α × d), where α represents 50 % of the desired angular correction, and d is the distance of the desired osteotomy site from the CORA. A simulated model was developed using TraumaCad online digital software suite (Brainlab AG, Germany). Osteotomies were simulated in the distal femur, proximal tibia and distal tibia for nine sets of lower limb scanograms at incremental distances from the CORA and the resulting translational deformity recorded. There was strong correlation between the distance of the osteotomy from the CORA and simulated translation deformity for distal femoral deformities (correlation coefficient 0.99, p < 0.0001), proximal tibial deformities (correlation coefficient 0.93-0.99, p < 0.0001) and distal tibial deformities (correlation coefficient 0.99, p < 0.0001). There was excellent agreement between the predictive algorithm and simulated translational deformity for all nine simulations (correlation coefficient 0.93-0.99, p < 0.0001). Translational deformity following corrective osteotomy for lower limb deformity can be anticipated and predicted based upon the angular correction and the distance between the planned osteotomy site and the CORA.

  18. Large-scale dynamic triggering of shallow slow slip enhanced by overlying sedimentary wedge

    Science.gov (United States)

    Wallace, Laura M.; Kaneko, Yoshihiro; Hreinsdóttir, Sigrún; Hamling, Ian; Peng, Zhigang; Bartlow, Noel; D'Anastasio, Elisabetta; Fry, Bill

    2017-10-01

    Slow slip events have become recognized in the last decade as an important mode of fault slip, and are most widely observed at subduction zones. Many episodes of tectonic tremor (related to slow slip) have been triggered by distant earthquakes due to dynamic-stress changes from passing seismic waves. However, there are few clear examples of large, geodetically detected slow slip events triggered by distant earthquakes. Here we use analyses of seismic and geodetic data to show that the magnitude 7.8 Kaikōura earthquake in New Zealand in 2016 triggered a large slow slip event between 250 and 600 km away. The slow slip was shallow, at less than 15 km deep, and spanned more than 15,000 km2 of the central and northern Hikurangi subduction margin. The slow slip initiated immediately after the earthquake, lasted one to two weeks and was accompanied by a swarm of seismicity. We show that changes in dynamic stress in the slow slip source area ranged from 100 to 600 kPa--approximately 1,000 times greater than the static-stress changes of 0.2 to 0.7 kPa. We therefore propose that the slow slip event was triggered by dynamic-stress changes caused by passing seismic waves. Furthermore, the dynamic-stress changes were greatest on the shallow subduction interface, at less than 10 km depth, in a region overlain by a sedimentary wedge that acts as a waveguide, trapping seismic energy and probably promoting triggering of slip. This suggests that shallow slow slip events are more easily triggered by dynamic-stress changes compared with deep events.

  19. Reporting quality of stepped wedge design randomized trials: a systematic review protocol.

    Science.gov (United States)

    Thabane, Alex; Dennis, Brittany B; Gajic-Veljanoski, Olga; Paul, James; Thabane, Lehana

    2016-01-01

    Stepped wedge design (SWD) is a cluster randomized controlled trial (RCT) design that sequentially rolls out intervention to all clusters at varying time points. Being a relatively new design method, reporting quality has yet to be explored, and this review will seek to fill this gap in knowledge. The objectives of this review are: 1) to assess the quality of SWD trial reports based on the CONSORT guidelines or CONSORT extension to cluster RCTs; 2) to assess the completeness of reporting of SWD trial abstracts using the CONSORT extension for abstracts; 3) to assess the reporting of sample size details in SWD trial reports or protocols; 4) to assess the completeness of reporting of SWD trial protocols according to SPIRIT guidelines; 5) to assess the consistency between the trial registration information and final SWD trial reports; and 6) to assess the consistency of what is reported in the abstracts and main text of the SWD trial reports. We will also explore factors that are associated with the completeness of reporting. We will search MEDLINE, EMBASE, Web of Science, CINAHL, and PsycINFO for all randomized controlled trials utilizing SWD. Details from eligible papers will be extracted in duplicate. Demographic statistics obtained from the data extraction will be analyzed to answer the primary objectives pertaining to the reporting quality of several aspects of a published paper, as well as to explore possible temporal trends and consistency between abstracts, trial registration information, and final published articles. Findings from this review will establish the reporting quality of SWD trials and inform academics and clinicians on their completeness and consistency. Results of this review will influence future trials and improve the overall quality and reporting of SWD trials.

  20. [Prevention of lateral cortex fractures in open wedge high tibial osteotomies : The anteroposterior drill hole approach].

    Science.gov (United States)

    Reyle, G; Lorbach, O; Diffo Kaze, A; Hoffmann, A; Pape, D

    2017-07-01

    In osteotomies with larger correction angles, the capacity for elastic deformation is frequently exceeded, resulting in plastic deformation and fracture of the opposite cortex, which may lead to subsequent loss of correction. An anteroposterior drill hole at the apex of the horizontal osteotomy (= hinge) is supposed to increase the capacity of the bony hinge for elastic deformation and ideally to prevent fractures of the opposite cortex. A high tibial osteotomy (HTO) using standard surgical technique was performed in 20 each of Synbones, Sawbones, and human cadaver tibial specimens. In 10 specimens per group, an additional anteroposterior hinge drilling was performed at the apex of the horizontal osteotomy. All fractures of the opposite cortex were photographically and radiographically documented. All fractures were classified according to fracture types 1-3 of the Takeuchi classification. Regardless of the study group, all tibial bones with an additional hinge drilling achieved larger correction angles during the spreading of the wedge until a fracture of the opposite cortex occurred. The average correction angle of all specimens without the drill hole was 2.7°, which increased to 4.8° with the hinge drill (increase by 77.8%). In correction angles exceeding 5°, all specimen showed a hinge fracture regardless of the presence or absence of a hinge drill. The hinge-protecting effect is restricted to small correction angles, i. e., to unload cartilage repair regions in the absence of severe malalignment. For the treatment of varus gonarthrosis, there is no fracture-protecting effect from a hinge drill.

  1. Implementation of protected mealtimes in the subacute setting: stepped wedge cluster trial protocol.

    Science.gov (United States)

    Porter, Judi; Haines, Terry; Truby, Helen

    2016-06-01

    This protocol paper describes a study that aims to determine if protected mealtimes implementation closes the energy deficit of 1900 kJ between estimated requirements and actual energy intake of hospitalized adults in the subacute setting. Protected mealtimes, a strategy developed to address the prevalence of malnourished hospitalized adults, aims to minimize unavoidable and unnecessary interruptions at mealtimes. It has been implemented widely with limited high-quality studies as to its effect. A pragmatic stepped wedge cluster trial. Primary outcomes are daily energy and protein intake. Funding was awarded in October 2014. In this study, protected mealtimes implementation will occur across each cluster (ward) chosen at random. A waiver of consent has been endorsed, enabling all patients to receive the intervention. Patients excluded from outcome evaluation will be those receiving end of life care and patients who are nil by mouth. The selection of patients for outcome evaluation will also occur randomly. Sample size, randomization, statistical analysis and contamination issues consider the reporting guidelines of the CONSORT statement: extension to cluster randomized trials. The methods selected will ensure that the research is of high quality with conclusions useful and relevant for translation into practice settings. The study does not aim to assess whether the intervention is sustainable beyond the study period, rather it will establish whether the removal of known barriers to intervention uptake enables high fidelity with the intervention. As a result we will have a greater understanding of the nutritional consequences of protected mealtimes in subacute care. © 2016 John Wiley & Sons Ltd.

  2. EVALUATION OF FUNCTIONAL RESULTS OF MEDIAL OPENING WEDGE HIGH TIBIAL OSTEOTOMY FOR UNICOMPARTMENTAL OSTEOARTHRITIS VARUS KNEE

    Directory of Open Access Journals (Sweden)

    Shyam Sundar Bakki

    2017-01-01

    Full Text Available BACKGROUND Osteoarthritis commonly affects the medial compartment of knee giving rise to varus deformity in majority of cases. Significant varus deformity further aggravates the pathology due to medialisation of the weight bearing line osteotomy of the proximal tibia realigns this weight bearing axis, thereby relieving pressure on the damaged medial compartment. OWHTO is a promising option in this scenario because it is associated with high accuracy in correcting the deformity and less number of complications when compared to lateral closing wedge HTO or UKA. In this study, we evaluate the functional outcome of HTO in patients with unicompartmental osteoarthritis. MATERIALS AND METHODS This is a prospective study of patients who attended the orthopaedic outpatient clinic in Government Hospital, Kakinada, between August 2013 to August 2015. The patients were evaluated by clinical examination and weight bearing radiographs. The patients who were found to have unicompartmental osteoarthritis with knee pain not relieved by conservative management and who satisfy the inclusion criteria were selected. RESULTS Excellent results can be achieved by appropriate selection criteria and planning with long limb weight bearing radiographs. There is an excellent relief of pain, which can be achieved within first few months postoperatively, which is assessed by VAS score. The KSS- knee score is excellent in 35%, good in 40%, fair in 20% and poor in 5%. The KSS- function score is excellent in 30%, good in 45%, fair in 20% and poor in 5%. There is significant improvement in the range of movement of the knee joint postoperatively. CONCLUSION In this study, we conclude that medial OWHTO is the preferred modality for unicompartmental OA in those aged <60 years and in developing nations like India where squatting is an important function, it has major role as it can restore near normal knee function without disturbing anatomy.

  3. Wedge resection and segmentectomy in patients with stage I non-small cell lung carcinoma

    Directory of Open Access Journals (Sweden)

    Konstantinos Reveliotis

    2014-09-01

    Full Text Available The use of sublobar resections as definitive management in stage I non-small cell lung carcinoma is a controversial topic in the medical community. We intend to report the latest developments and trends in relative indications for each of the above-mentioned surgical approaches for the treatment of stage I non-small cell lung carcinoma as well as the results of studies regarding local recurrence, disease-free survival and five-year survival rates. We reviewed 45 prospective and retrospective studies conducted over the last 25 years listed in the Pubmed and Scopus electronic databases. Trials were identified through bibliographies and a manual search in journals. Authors, citations, objectives and results were extracted. No meta-analysis was performed. Validation of results was discussed. Segmentectomies are superior to wedge resections in terms of local recurrences and cancer-related mortality rates. Sublobar resections are superior to lobectomy in preserving the pulmonary parenchyma. High-risk patients should undergo segmentectomy, whereas lobectomies are superior to segmentectomies only for tumors >2 cm (T2bN0M0 in terms of disease-free and overall 5-year survival. In most studies no significant differences were found in tumors <2 cm. Disease-free surgical margins are crucial to prevent local recurrences. Systematic lymphadenectomy is mandatory regardless of the type of resection used. In sublobar resections with less thorough nodal dissections, adjuvant radiotherapy can be used. This approach is preferable in case of prior resection. In pure bronchoalveolar carcinoma, segmentectomy is recommended. Sublobar resections are associated with a shorter hospital stay. The selection of the type of resection in T1aN0M0 tumors should depend on characteristic of the patient and the tumor. Patient age, cardiopulmonary reserve and tumor size are the most important factors to be considered. However further prospective randomized trials are needed to

  4. Impact of tool wear on cross wedge rolling process stability and on product quality

    Science.gov (United States)

    Gutierrez, Catalina; Langlois, Laurent; Baudouin, Cyrille; Bigot, Régis; Fremeaux, Eric

    2017-10-01

    Cross wedge rolling (CWR) is a metal forming process used in the automotive industry. One of its applications is in the manufacturing process of connecting rods. CWR transforms a cylindrical billet into a complex axisymmetrical shape with an accurate distribution of material. This preform is forged into shape in a forging die. In order to improve CWR tool lifecycle and product quality it is essential to understand tool wear evolution and the physical phenomena that change on the CWR process due to the resulting geometry of the tool when undergoing tool wear. In order to understand CWR tool wear behavior, numerical simulations are necessary. Nevertheless, if the simulations are performed with the CAD geometry of the tool, results are limited. To solve this difficulty, two numerical simulations with FORGE® were performed using the real geometry of the tools (both up and lower roll) at two different states: (1) before starting lifecycle and (2) end of lifecycle. The tools were 3D measured with ATOS triple scan by GOM® using optical 3D measuring techniques. The result was a high-resolution point cloud of the entire geometry of the tool. Each 3D point cloud was digitalized and converted into a STL format. The geometry of the tools in a STL format was input for the 3D simulations. Both simulations were compared. Defects of products obtained in simulation were compared to main defects of products found industrially. Two main defects are: (a) surface defects on the preform that are not fixed in the die forging operation; and (b) Preform bent (no longer straight), with two possible impacts: on the one hand that the robot cannot grab it to take it to the forging stage; on the other hand, an unfilled section in the forging operation.

  5. Effect of cranial tibial closing wedge angle on tibial subluxation: an ex vivo study.

    Science.gov (United States)

    Apelt, Detlef; Pozzi, Antonio; Marcellin-Little, Denis J; Kowaleski, Michael P

    2010-06-01

    To evaluate the effect of cranial tibial wedge osteotomy (CTWO) angle on cranial tibial subluxation (CTS) and postoperative tibial plateau angle (TPA). Ex vivo biomechanical study. Canine pelvic limbs (n=6). TPA determined from a lateral radiographic projection. CTS under 30% body weight load was measured from radiographs in the intact limb and after transection of the cranial cruciate ligament. A CTWO equal to TPA+10 degrees was performed at the distal extent of the tibial crest, and was stabilized with a custom designed hinge plate and external skeletal fixator. TPA and CTS in the loaded limb was determined from radiographs at 4 CTWO angles: TPA-5 degrees, TPA, TPA+5 degrees, and TPA+7.5 degrees. Comparison of CTS between the intact limb and the 4 CTWO angle groups was performed using 1-way repeated-measures ANOVA and a Dunnett multiple comparison test (significance at P<.05). CTS was significantly greater than that of the intact limb in the TPA-5 degrees and TPA groups. CTS was not significantly different from the intact limb in the TPA+5 degrees or TPA+7.5 degrees groups with corresponding TPAs of 5.9 degrees and 3.8 degrees, respectively. Using this model, CTS was neutralized at a TPA of approximately 4-6 degrees with a CTWO angle between TPA+5 degrees and TPA+7.5 degrees. A CTWO angle between TPA+5 degrees and TPA+7.5 degrees is necessary to neutralize CTS and achieve a postoperative TPA of 4-6 degrees if the CTWO is performed at the distal extent of the tibial crest and the caudal cortices are aligned.

  6. High Rate of Recurrence Following Proximal Medial Opening Wedge Osteotomy for Correction of Moderate Hallux Valgus.

    Science.gov (United States)

    Iyer, Sravisht; Demetracopoulos, Constantine A; Sofka, Carolyn M; Ellis, Scott J

    2015-07-01

    The proximal medial opening wedge (PMOW) osteotomy has become more popular to treat moderate to severe hallux valgus with the recent development of specifically designed, low-profile modular plates. Despite the promising results previously reported in the literature, we have noted a high incidence of recurrence in patients treated with a PMOW. The purpose of this study was to report the clinical and radiographic outcomes of an initial cohort of patients treated with a PMOW osteotomy for moderate hallux valgus. We retrospectively analyzed prospectively gathered data on a cohort of 17 consecutive patients who were treated by the senior author using a PMOW osteotomy for moderate hallux valgus deformity. Average time to follow-up was 2.4 years (range, 1.0-3.5 years). The intermetatarsal angle (IMA), the hallux valgus angle (HVA), and the distal metatarsal articular angle (DMAA) were assessed on standard weightbearing radiographs of the foot preoperatively and at all follow-up visits. The Foot and Ankle Outcome Score (FAOS) was collected on all patients preoperatively and at final follow-up. Despite demonstrating good correction of their deformity initially, 11 of the 17 patients (64.7%) had evidence of recurrence of their hallux valgus deformity at final follow-up. Patients who recurred had a greater preoperative HVA (P = .023) and DMAA (P = .049) than patients who maintained their correction. Improvement in the quality-of-life subscale of the FAOS was noted at final follow-up for all patients (P = .05). There was no significant improvement in any of the other FAOS subscales. There was a high rate of recurrence of the hallux valgus deformity in this cohort of patients. Recurrence was associated with greater preoperative deformity and an increased preoperative DMAA. The PMOW without a concomitant distal metatarsal osteotomy may be best reserved for patients with mild hallux valgus deformity without an increased DMAA. Level IV, retrospective case series. © The Author

  7. Constraining exhumation pathway in an accretionary wedge by (U-Th)/He thermochronology—Case study on Meliatic nappes in the Western Carpathians

    Science.gov (United States)

    Putiš, Marián; Danišík, Martin; Ružička, Peter; Schmiedt, Ivan

    2014-11-01

    This study reconstructs the late stages in the exhumation history of a nappe derived from the Meliatic accretionary wedge in the Western Carpathians by means of zircon and apatite (U-Th)/He dating. The Meliatic accretionary wedge formed due to the closure of the Neotethyan Triassic-Jurassic Meliata-Hallstatt Ocean in the Late Jurassic. The studied fragments of the blueschist-bearing Meliatic Bôrka Nappe were metamorphosed at low-temperature and high- to medium-pressure conditions at ca. 160-150 Ma and included into the accretionary wedge. The time of the accretionary wedge formation constrains the beginning of the Bôrka Nappe northward thrusting over the Gemeric Unit of the evolving Central Western Carpathians (CWC) orogenic wedge. The zircon (U-Th)/He data on four samples recorded three evolutionary stages: (i) cooling through the ∼180 °C isotherm at 130-120 Ma related to starting collapse of the accretionary wedge, following exhumation of the high-pressure slices in the Meliatic accretionary wedge; (ii) postponed exhumation and cooling of some fragments through the ∼180 °C isotherm from 115 to 95 Ma due to ongoing collapse of this wedge; and (iii) cooling from 80 to 65 Ma, postdating the thrusting (∼100-80 Ma) of the Bôrka Nappe slices during the Late Cretaceous compression related to formation of the CWC orogenic wedge. The third stage already documents cooling of the Meliatic Bôrka Nappe slices in the CWC orogenic wedge. The apatite (U-Th)/He data may indicate cooling of a Bôrka Nappe slice to near-surface temperatures at ∼65 Ma. The younger AHe age clusters indicate that at least one, or possibly two, reheating events could have occurred in the longer interval from ∼40 to ∼10 Ma during the Oligocene-Miocene. These were related to sedimentary burial and/or the magmatism as documented in other parts of the CWC.

  8. John Deakin: Double Exposures

    Directory of Open Access Journals (Sweden)

    Paul Rousseau

    2015-11-01

    Full Text Available In this series of short films made by Jonathan Law, the art historian James Boaden, and the curator of The John Deakin Archive, Paul Rousseau, discuss the double-exposure images made by the photographer John Deakin (1912-1972 in the 1950s and 1960s. The films ask you, firstly, to look closely at the images being discussed. Each one begins with a sustained and intense shot of a single image before opening up to a wide-ranging discussion about Deakin, double exposures, and photography.

  9. Double arch mirror study

    Science.gov (United States)

    Vukobratovich, D.; Hillman, D.

    1983-01-01

    The development of a method of mounting light weight glass mirrors for astronomical telescopes compatible with the goals of the Shuttle Infrared Telescope Facility (SIRTF) was investigated. A 20 in. diameter double arch lightweight mirror previously fabricated was modified to use a new mount configuration. This mount concept was developed and fabricated. The mounting concept of the double mounting mirror is outlined. The modifications made to the mirror, fabrication of the mirror mount, and room temperature testing of the mirror and mount and the extension of the mirror and mount concept to a full size (40 in. diameter) primary mirror for SIRTF are discussed.

  10. Double-Barred Galaxies

    OpenAIRE

    Erwin, Peter

    2009-01-01

    I present a brief review of what is known about double-barred galaxies, where a small ("inner") bar is nested inside a larger ("outer") bar; the review is focused primarily on their demographics and photometric properties. Roughly 20% of S0--Sb galaxies are double-barred; they may be rarer in later Hubble types. Inner bars are typically ~ 500 pc in radius (~ 12% the size of outer bars), but sizes range from ~ 100 pc to > 1 kpc. The structure of at least some inner bars appears very similar to...

  11. Sedimentary Processes of Unstable Ice Sheet Grounding Zones: Comparing Polar and Temperate Grounding Zone Wedges Using Marine Geophysical Data and Outcrop Studies

    Science.gov (United States)

    Demet, B. P.; Anderson, J. B.; Nittrouer, J. A.; Simkins, L.; Halberstadt, A. R.; Prothro, L. O.

    2015-12-01

    Current understanding of ice sheet grounding zone dynamics is limited because direct observation of grounding zones and their deposits (grounding zone wedges, GZW) is restricted to marine geophysical methods, which provide large-scale measurements of planform morphology and internal stratigraphy, but little information regarding sedimentary architecture. Seismic data nevertheless reveal that GZW range meters to kilometers in length scale and typically possess foresets and incised channels. Sediment cores from measured wedges are helpful for evaluating vertical changes in stratigraphy, but leave significant uncertainty regarding the spatial variability of deposits and the nature of their contacts, which are necessary data to evaluate sedimentary processes operating within grounding zones. This study presents results from outcrop studies of GZW exposed in sea cliffs of the Puget Sound, Washington (U.S.A.), where a series of back-stepping GZW record rapid grounding line retreat of the Puget Lobe. These outcrops are used to evaluate first-order physical controls on depositional processes. The data are compared to geophysical observations and cores collected from the Ross Sea, Antarctic, to evaluate similarities between the outcrop-scale deposits and polar grounding zone wedges that possess wavelengths measuring several kilometers, and amplitudes of tens of meters. The preliminary results show that for these larger features, wedge progradation is facilitated by foreset deposition. Alternatively, for small-scale wedges (100's of m wavelength, m-scale amplitudes), wedge development occurs through topset aggradation. Additionally, based on the Puget Sound GZW deposits, progradation arises due to sediment gravity flows on the foreset. Sand and silt couplets, preserved within wedge foresets, suggest that tidal pumping occurred under ice, producing deposits between punctuated sediment gravity flows. These data show a multitude of sedimentary and morphological scales that are

  12. Regional Patterns of Ice-Wedge Degradation Across Northern Alaska: What Does Asynchronous Timing of Onset Tell Us Regarding Triggering Mechanisms, Thresholds, and Impacts?

    Science.gov (United States)

    Frost, G. V., Jr.; Macander, M. J.; Liljedahl, A. K.; Walker, D. A.

    2015-12-01

    Ice-wedge polygons are conspicuous and widespread in arctic landscapes, creating complex microtopography and strong, meter-scale contrasts in hydrology, soil, vegetation, and ground ice conditions. Thaw of the upper portion of ice-wedges results in ground subsidence (thermokarst), plant mortality and the formation of small, flooded pits along the polygon margins. Secondary impacts, such as changes in flowpaths, spatially-variable flooding and drainage of polygon centers, and thermal erosion of permafrost, extend well beyond the thermokarst pits themselves. We delineated small waterbodies in historical airphotos and modern high-resolution satellite imagery and made ground observations across a network of 45 km2 study areas spanning the western and central regions of Alaska's North Slope. The imagery archive covers three epochs: 1948-1955, 1979-1985, and 2009-2012. Our analysis focused on residual upland surfaces dominated by Holocene-aged ice wedges, where surface water is mainly restricted to degraded ice-wedges. Total extent of flooded pits increased at most landscapes since circa 1980 (range -27 - +135%; median +10.6%). An intriguing regional pattern was evident: degradation of Holocene ice-wedges was already well underway by 1950 across much of the western North Slope, but degradation initiated much more recently on eolian sand and silt (yedoma) deposits prevalent to the east. Our results indicate that recent degradation of Holocene ice wedges across northern Alaska cannot be explained by late-20th century warmth alone. Possible mechanisms for earlier onset of degradation on the western North Slope include differences in recent climate history, snow regime, and thermal and physical properties of surficial materials. These findings provide context for interpreting and predicting ice-wedge thermokarst processes, thresholds, and impacts in Alaska and elsewhere in the circumpolar arctic.

  13. Aristotle and Double Effect

    DEFF Research Database (Denmark)

    Di Nucci, Ezio

    2014-01-01

    There are some interesting similarities between Aristotle’s ‘mixed actions’ in Book III of the Nicomachean Ethics and the actions often thought to be justifiable with the Doctrine of Double Effect. Here I analyse these similarities by comparing Aristotle’s examples of mixed actions with standard ...

  14. Neutrinoless double beta decay

    Indian Academy of Sciences (India)

    2015-11-27

    Nov 27, 2015 ... Abstract. The physics potential of neutrinoless double beta decay is discussed. Furthermore, experimental considerations as well as the current status of experiments are presented. Finally, an outlook towards the future, work on nuclear matrix elements and alternative processes is given.

  15. Double-Glazing Interferometry

    Science.gov (United States)

    Toal, Vincent; Mihaylova, Emilia M.

    2009-01-01

    This note describes how white light interference fringes can be seen by observing the Moon through a double-glazed window. White light interferometric fringes are normally observed only in a well-aligned interferometer whose optical path difference is less than the coherence length of the light source, which is approximately one micrometer for…

  16. Double beta decay

    Energy Technology Data Exchange (ETDEWEB)

    Bryman, D.; Picciotto, C.

    1978-01-01

    The problem of double beta decay is reviewed with emphasis on its relevance to lepton number conservation. Recently, the ratio of the double beta-decay half-lives of /sup 128/Te and /sup 130/Te has been measured in a geological experiment and a limit for the ratio of the neutrinoless rate to the total rate for /sup 82/Se decay has been obtained from a direct-detection experiment. For the first time, these results show conclusively that double beta decay is not primarily a lepton-number-violating neutrinoless process. However, they also do not agree with calculations which assume that only lepton-number-conserving two-neutrino double beta decay occurs. The conclusion that lepton number conservation is violated is suggested by limited experimental information. By considering contributions to the total rate from both the two-neutrino and the neutrinoless channels, we obtain data which are consistent with a lepton nonconservation parameter of order eta=3.5 x 10/sup -5/. Roughly the same value of eta is obtained by assuming that the decay occurs either via lepton emission from two nucleons or via emission from a resonance in the nucleus.

  17. Design for Double Rainbow

    Science.gov (United States)

    Thomas, Lisa Carlucci

    2011-01-01

    Rare is the inspirational, spontaneous, transformative moment shared among 20 million people. In the summer of 2010, people around the world were moved by the sighting of a double rainbow--almost a triple rainbow--"all the way across the sky" in Yosemite National Park. Caught on video and posted to by YouTube by Paul Vasquez in January 2010, the…

  18. Generalizing double graphs

    Directory of Open Access Journals (Sweden)

    Zagaglia Salvi, Norma

    2007-10-01

    Full Text Available In this paper we study the graphs which are direct product of a simple graph G with the graphs obtained by the complete graph Kk adding a loop to each vertex; thus these graphs turn out to be a generalization of the double graphs.

  19. Hybrid Double Quantum Dots

    DEFF Research Database (Denmark)

    Sherman, D.; Yodh, J. S.; Albrecht, S. M.

    2016-01-01

    Epitaxial semiconductor-superconductor hybrid materials are an excellent basis for studying mesoscopic and topological superconductivity, as the semiconductor inherits a hard superconducting gap while retaining tunable carrier density. Here, we investigate double-quantum-dot devices made from InA...... that the individual dots host weakly hybridized Majorana modes....

  20. The impact of slab dip variations, gaps and rollback on mantle wedge flow: insights from fluids experiments

    Science.gov (United States)

    MacDougall, Julia G.; Kincaid, Chris; Szwaja, Sara; Fischer, Karen M.

    2014-05-01

    Observed seismic anisotropy and geochemical anomalies indicate the presence of 3-D flow around and above subducting slabs. To investigate how slab geometry and velocity affect mantle flow, we conducted a set of experiments using a subduction apparatus in a fluid-filled tank. Our models comprise two independently adjustable, continuous belts to represent discrete sections of subducting slabs that kinematically drive flow in the surrounding glucose syrup that represents the upper mantle. We analyse how slab dip (ranging from 30° to 80°), slab dip difference between slab segments (ranging from 20° to 50°), rates of subduction (4-8 cm yr-1) and slab/trench rollback (0-3 cm yr-1) affect mantle flow. Whiskers were used to approximate mineral alignment induced by the flow, as well as to predict directions of seismic anisotropy. We find that dip variations between slab segments generate 3-D flow in the mantle wedge, where the path lines of trenchward moving mantle material above the slab are deflected towards the slab segment with the shallower dip. The degree of path line deflection increases as the difference in slab dip between the segments increases, and, for a fixed dip difference, as slab dip decreases. In cases of slab rollback and large slab dip differences, we observe intrusion of subslab material through the gap and into the wedge. Flow through the gap remains largely horizontal before eventual downward entrainment. Whisker alignment in the wedge flow is largely trench-normal, except near the lateral edges of the slab where toroidal flow dominates. In addition, whisker azimuths located above the slab gap deviate most strongly from trench-normal orientations when slab rollback does not occur. Such flow field complexities are likely sufficient to affect deep melt production and shallow melt delivery. However, none of the experiments produced flow fields that explain the trench-parallel shear wave splitting fast directions observed over broad arc and backarc

  1. Wedge resection for non-small cell lung cancer in patients with pulmonary insufficiency: prospective ten-year survival.

    Science.gov (United States)

    Griffin, John P; Eastridge, Charles E; Tolley, Elizabeth A; Pate, James W

    2006-11-01

    Possibility of curative resection by lobectomy for non-small cell lung cancer is often denied patients with compromised pulmonary reserve. Analysis of survival of such patients treated by wedge resection was compared with that of patients treated by standard resection, with both groups followed for 10 years. A prospective 5-year cohort study. From 1988 to 1992, an observational cohort of 127 consecutive resected patients at Memphis VA Medical Center was divided into those receiving lobectomy in 81 cases and pneumonectomy in 15 cases (group I) versus 31 patients with compromised pulmonary reserve (group II), who had complete tumor excision by wedge resection. Preoperative clinical staging was corrected to surgical-pathological staging after demonstration of its superiority. Survival estimates were obtained by Kaplan-Meier method with curves compared by log rank tests, with all-cause mortality calculated from date of surgery. Extent of disease in group I was 58% stage I, 19% stage II, and 23% stage III. In group II, extent of disease was 84% stage I, 3% stage II, and 14% stage III. Group I median survival was 26 months with 30% 5-year survival; for group II, median survival was 30 months and 32%. Kaplan-Meier survival plots showed similar curves in groups I and II. Realizing less extent of disease in group II, another Kaplan-Meier plot restricted to stage I and II patients showed overlapping survival curves for groups I and II. Survival during 10-year observation was similar for patients with pulmonary insufficiency treated by wedge resection to that of patients receiving standard resection in this single-institution consecutive cohort.

  2. B-type olivine fabric induced by low temperature dissolution creep during serpentinization and deformation in mantle wedge

    Science.gov (United States)

    Liu, Wenlong; Zhang, Junfeng; Barou, Fabrice

    2018-01-01

    The B-type olivine fabric (i.e., the [010] axes subnormal to foliation and the [001] axes subparallel to the lineation) has been regarded as an important olivine fabric for interpreting global trench-parallel S-wave polarization in fore-arc regions. However, strong serpentinization and cold temperature environment in the mantle wedge should inhibit development of the B-type olivine fabric that requires high temperature to activate solid-state plastic deformation. Here we report fabrics of olivine and antigorite generated at low temperatures (300-370 °C) during serpentinization in a fossil mantle wedge of the Val Malenco area, Central Alps. Olivine in the serpentine matrix develops a pronounced B-type fabric, while antigorite in the same matrix displays a strong crystallographic preferred orientation (CPO) with the (001) planes and the [010] axes subparallel to foliation and lineation, respectively. The following evidence leads to the conclusion that the B-type olivine fabric results from dissolution creep assisted by grain boundary sliding (GBS) and grain rotation, rather than solid-state plastic deformation: (1) serpentinization took place at low temperatures and a fluid-enriched environment, ideal for dissolution-precipitation creep; (2) the voids and zigzag boundaries along the interface between antigorite and olivine suggest a fluid dissolution reaction; (3) the primary coarse olivine develops a nearly random fabric, indicating the B-type fabrics in the fine-grained olivine may not be inherited fabrics. These results document for the first time the B-type olivine CPO formed by dissolution creep at low temperatures during serpentinization and provide a mechanism to reconcile petrofabric observations with geophysical observations of trench parallel fast S-wave seismic anisotropy in fore-arc mantle wedge regions.

  3. [Effectiveness of penile ventral scrotum cohesion place wedge cutting and improved Brisson technique for congenital buried penis].

    Science.gov (United States)

    Zhang, Huafeng

    2013-09-01

    To investigate the effectiveness of the penile ventral scrotum cohesion place wedge cutting and improved Brisson technique for congenital buried penis. Between March 2010 and June 2012, 68 boys with congenital buried penis were treated by the penile ventral scrotum cohesion place wedge cutting and improved Brisson technique, with a median age of 4 years and 10 months (range, 3 months-13 years). Of 68 cases, 14 were classified as phimosis type, 14 as rope belt type, 20 as moderate type, and 20 as severe type. The body of penis developed well and had no deformity. After operation, complications were observed, and the effectiveness was evaluated by the designed questionnaire. Early postoperative complications occurred in 11 cases, including obvious adhesion of the outside wrapping mouth in 4 cases, scrotal skin bloat in 5 cases, and distal foreskin necrosis in 2 cases; long-term complications occurred in 9 cases, including abdominal incision scar formation in 4 cases, wrapping mouth scar stricture in 3 cases, and short penis in 2 cases. Primary healing of incision was obtained in the other boys. Fifty-four cases were followed up 6-12 months (mean, 8 months). According to the designed questionnaire, satisfaction rate with the overall view in parents was 77.78% (42/54); the clinical improvement rate was 85.19% (46/54); exposure of the penis was satisfactory in parents of 50 cases; and the parents had no psychological burden of penis exposure in 46 cases, which were significantly improved when compared with preoperative ones (P penis exposure in 29 cases (53.70%) after operation, showing no significant difference when compared with preoperative one (18 cases, 33.33%) (chi2 = 1.22, P = 0.31). Application of the penile ventral scrotum cohesion place wedge cutting and improved Brisson technique can effectively correct congenital buried penis.

  4. SU-F-P-34: Commission of Enhanced Dynamic Wedge of Varian Truebeam Linac System with Feature Study

    Energy Technology Data Exchange (ETDEWEB)

    Li, K; Able, A [Associates In Medical Physics, Lanham, MD (United States)

    2016-06-15

    Purpose: To evaluate an Enhanced Dynamic Wedge (EDW) as part of machine commission process with feature study. Methods: The EDW system in this study was from a Truebeam, which is the Linear accelerator manufactured by Varian Medical Systems. The EDW feature vectors includes selected elements. These elements were dosimetric output spots check, field size, wedge angles, dose rate, collimator orientation, and different energy settings. Point dose measurement was done by a PTW farmer chamber, and profiles were measured by Gafchromic EBT2 films positing at different depths of the Solidwater based on the study elements. The output spot measurements were done with PTW farmer chamber with Solidwater setting for all orientation and wedge angles in the EDW system. The profiles comparisons were done by IMRT measurement function in RIT software at version 6.3. And the films were scanned by Vidar scanner. Dosimetry calculation were done by using the same Solidwater scanned by GE LightSpeed CT in Eclipse Treatment Planning System (TPS). Then measurements were compared to simulation results in TPS. Results: The energy average percentage difference between chamber measurement and TPS was 0.16% with standard deviation (SD) at 0.93%. For selected features, the average percentage difference between film measurement and computation was 0.93% with SD at 1.55% in horizontal profiles, and 1.18% with SD at 0.98% at vertical profiles. The average gamma difference for film measurement and TPS computing results was at 0.924 with SD at 0.314. Conclusion: A feature vector was developed to describe the commission of EDW, and developing a complete set of features for sufficiency of commission of a LINAC function could provide optimal commission instance with acceptable confident level of clinical application of the machine. Given the institution specific vector pattern and big data process, it could provide wide range clinical outcome comparison information in application of EDW.

  5. [Open-wedge osteotomy of the glenoid for treatment of posterior shoulder instability with increased glenoid retroversion].

    Science.gov (United States)

    Pogorzelski, J; Braun, S; Imhoff, A B; Beitzel, K

    2016-12-01

    Treatment of posterior shoulder instability with increased retroversion of the glenoid using open-wedge osteotomy of the glenoid neck stabilized with an autologous bone block. Symptomatic, atraumatic posterior shoulder instability with increased retroversion (>20°) of the glenoid and previously failed conservative or surgical treatment. General contraindications against surgery. Relative contraindications: osteoporosis, nicotine abuse, or suspected patient noncompliance. Posterior approach with a 7 cm long incision starting medial of the posterolateral corner of the acromion heading to the posterior axillary fold and subsequent preparation of the deltoid muscle and the infraspinatus muscle. The posterior glenohumeral capsule is incised by performing a capsular T‑shift. The osteotomy is performed intracapsulary medial to the genoid rim. The wedge bone graft, harvested from spina scapulae or iliac spine, is placed "press fit" in position. Additional fixation of the graft is not necessary if the anterior cortex is intact. For reinforcing the posterior capsule, a posterior capsule shift should be performed. Insertion of extracapsular wound drainage. Successive wound closure. Postoperative immobilization in a 0° shoulder orthesis for 6 weeks; avoidance of horizontal abduction for 8 weeks. After removing the wound drainage, start of limited active-assisted range of motion. Over-head sports after 6 months. From 2009-2015, 6 posterior open wedge glenoid osteotomies were performed. Postoperative retroversion of the glenoid was 11.2 ± 9.4° compared to 26.0 ± 8.6° before surgery. Of 6 shoulders, 2 showed postoperative signs of persistent posterior instability; the other 4 shoulders were free of complaints. No revision surgery was needed.

  6. Mantle Wedge formation during Subduction Initiation: evidence from the refertilized base of the Oman ophiolitic mantle

    Science.gov (United States)

    Prigent, C.; Guillot, S.; Agard, P.; Godard, M.; Lemarchand, D.; Ulrich, M.

    2015-12-01

    extracted at different degrees until getting ultimately trapped, and crystallized cpx, amph and other associated minerals. If our interpretation is correct, the base of the Oman ophiolite could provide the best proxy for the composition of a frozen-in, incipiently forming mantle wedge.

  7. Precommitting to choose wisely about low-value services: a stepped wedge cluster randomised trial.

    Science.gov (United States)

    Kullgren, Jeffrey Todd; Krupka, Erin; Schachter, Abigail; Linden, Ariel; Miller, Jacquelyn; Acharya, Yubraj; Alford, James; Duffy, Richard; Adler-Milstein, Julia

    2017-10-24

    Little is known about how to discourage clinicians from ordering low-value services. Our objective was to test whether clinicians committing their future selves (ie, precommitting) to follow Choosing Wisely recommendations with decision supports could decrease potentially low-value orders. We conducted a 12-month stepped wedge cluster randomised trial among 45 primary care physicians and advanced practice providers in six adult primary care clinics of a US community group practice.Clinicians were invited to precommit to Choosing Wisely recommendations against imaging for uncomplicated low back pain, imaging for uncomplicated headaches and unnecessary antibiotics for acute sinusitis. Clinicians who precommitted received 1-6 months of point-of-care precommitment reminders as well as patient education handouts and weekly emails with resources to support communication about low-value services.The primary outcome was the difference between control and intervention period percentages of visits with potentially low-value orders. Secondary outcomes were differences between control and intervention period percentages of visits with possible alternate orders, and differences between control and 3-month postintervention follow-up period percentages of visits with potentially low-value orders. The intervention was not associated with a change in the percentage of visits with potentially low-value orders overall, for headaches or for acute sinusitis, but was associated with a 1.7% overall increase in alternate orders (p=0.01). For low back pain, the intervention was associated with a 1.2% decrease in the percentage of visits with potentially low-value orders (p=0.001) and a 1.9% increase in the percentage of visits with alternate orders (p=0.007). No changes were sustained in follow-up. Clinician precommitment to follow Choosing Wisely recommendations was associated with a small, unsustained decrease in potentially low-value orders for only one of three targeted conditions and

  8. Laparoscopic Wedge Resection of Gastrojejunostomy for Weight Recidivism after Gastric Bypass.

    Science.gov (United States)

    Elbahrawy, Aly; Bougie, Alexandre; Albader, Mohammad; Aggarwal, Rajesh; Demyttenaere, Sebastian; Andalib, Amin; Court, Olivier

    2017-11-01

    Weight recidivism after Roux-en-Y gastric bypass (RYGB) is a common problem. Often, this weight loss failure or regain may be due to a wide gastrojejunostomy (GJ). We evaluated the feasibility and safety of a novel approach of laparoscopic wedge resection of gastrojejunostomy (LWGJ) for a wide stoma after RYGB associated with weight recidivism. This is a single-center retrospective study of a prospectively collected database. We analyzed outcomes of patients with weight recidivism after RYGB and a documented wide GJ (>2 cm) on imaging, who underwent LWGJ between 11/2013 and 05/2016. Nine patients underwent LWGJ for dilated stomas. All patients were female with a mean ± SD age of 53 ± 7 years. Mean interval between RYGB and LWGJ was 9 ± 3 years. All cases were performed laparoscopically with no conversions. Mean operative time and hospital stay were 86 ± 9 min and 1.2 ± 0.4 days, respectively. The median(IQR) follow-up time was 14(12-18) months. During follow-up, there were no deaths, postoperative complications, or unplanned readmissions or reoperations. The mean and median(IQR) BMI before RYGB and LWGJ were 55.4 ± 8.1 kg/m 2 and 56.1(47.9-61.7) and 43.4 ± 8.6 kg/m 2 and 42.1(38.3-47.1), respectively. One year after LWGJ, mean and median(IQR) BMI significantly decreased to 34.9 ± 7.3 kg/m 2 and 33.3(31.7-35.0) corresponding to a mean %EWL of 64.6 ± 19.9 (P recidivism after RYGB with a wide GJ (>2 cm). Long-term follow-up is needed to determine the efficacy and durability of LWGJ and compare its outcomes with other endoscopic/surgical approaches for weight recidivism after RYGB with a documented wide GJ.

  9. The role of bone void fillers in medial opening wedge high tibial osteotomy: a systematic review.

    Science.gov (United States)

    Slevin, Omer; Ayeni, Olufemi R; Hinterwimmer, Stefan; Tischer, Thomas; Feucht, Matthias J; Hirschmann, Michael T

    2016-11-01

    A variety of bone void filling materials and methods are available in opening medial wedge HTO (OWHTO). The pertinent question revolves around if and when bone void fillers are needed. The primary purpose of this study was to systematically review outcomes and complications after OWHTO with and without the use of bone void fillers. The EMBASE, PubMed\\MEDLINE, Cochrane Library and Google Scholar databases were searched to identify articles that reported OWHTO results using different bone void fillers until March 2016. Only articles reporting the exact bone void filler type, the opening gap size and the fixation method were included. The extracted data included the study design, demographic data, the radiological and clinical results and complication rates. Outcomes were analysed with regard to bone void filler type, and comparison was made between the groups (allograft, autograft, synthetic bone void filler and OWHTO without bone void filling). Twenty-two articles reporting the results of 1421 OWHTO met the inclusion criteria. In total, 647 osteotomies were completed with allogeneic graft as bone void filler, 367 with synthetic materials, 199 with autograft and 208 without any bone void filling material. The maximum opening gap size was similar in all groups with mean of 9.8 mm (range 4-17.5 mm). Locking plate fixation was used in 90 % of the osteotomies that were completed without bone void filler, while all allograft cases and more then 90 % of the autograft cases were done with non-locking systems. The highest rates of non-union (1.1 %) were seen in the synthetic group, compared to 0.5 % in the all the other groups. This systematic review showed no definitive advantages for OWHTO with any bone void filler in terms of union rates and loss of correction. Moreover, the use of autografts or allografts showed more favourable outcomes than synthetic bone substitutes. OWHTO with gaps smaller then 10 mm and rigid fixation might be successfully managed without

  10. Mechanical properties of the Sevier Desert detachment: an application of Critical Coulomb Wedge theory

    Science.gov (United States)

    Christie-Blick, N.; Yuan, X.

    2016-12-01

    Low-angle normal faults are widely regarded as playing an important role in crustal extension. Among the most influential examples, the Sevier Desert detachment (SDD) has been imaged in seismic reflection profiles beneath the Sevier Desert basin of west-central Utah. An extensional offset of as much as 47 km is thought to have occurred since the late Oligocene at or near its present dip of 11° (DeCelles and Coogan, 2006, GSAB 118, 841-864). We use the palinspastic geometry of the pre-extensional Sevier orogen and Critical Coulomb Wedge (CCW) theory to constrain the friction coefficient, μD of the inferred detachment. It is assumed that the SDD is at least in part a reactivated strand of the Pavant thrust system. Compressive CCW theory suggests μD values of 0.2-0.24 for thrust faults when crustal shortening ceased in the early Tertiary. A decrease in the dip of the SDD from a maximum of 30° to its present-day inclination of 11° implies that μD decreased from 0.2 initially (and ≤ 0.35, if the extensional upper limit is assumed) to 0.13 today, based on extensional CCW theory. Salt, for which the normal stress dependence of the friction equation disappears with even shallow burial (Davis and Engelder, 1985, Tectonophysics 119, 67-88), is widespread in the Sevier Desert basin (Wills et al., 2005, AJS 305, 42-100), and present locally also in Jurassic strata of central Utah. Elevated pore fluid pressure would have reduced the effective normal stress, but values appreciably greater than hydrostatic are not expected in the geological setting of the Sevier Desert. Our model and the structural geometry on which it depends can be tested directly by coring across the inferred detachment, and by measuring material properties and the pore fluid pressure in the vicinity of the contact. Resolving the origin of this feature will have far-reaching implications for mechanisms of crustal extension.

  11. Environmental enrichment intervention for Rett syndrome: an individually randomised stepped wedge trial.

    Science.gov (United States)

    Downs, Jenny; Rodger, Jenny; Li, Chen; Tan, Xuesong; Hu, Nan; Wong, Kingsley; de Klerk, Nicholas; Leonard, Helen

    2018-01-10

    Rett syndrome is caused by a pathogenic mutation in the MECP2 gene with major consequences for motor and cognitive development. One of the effects of impaired MECP2 function is reduced production of Brain Derived Neurotrophic Factor (BDNF), a protein required for normal neuronal development. When housed in an enriched environment, MECP2 null mice improved motor abilities and increased levels of BDNF in the brain. We investigated the effects of environmental enrichment on gross motor skills and blood BDNF levels in girls with Rett syndrome. A genetically variable group of 12 girls with a MECP2 mutation and younger than 6 years participated in a modified individually randomised stepped wedge design study. Assessments were conducted on five occasions, two during the baseline period and three during the intervention period. Gross motor function was assessed using the Rett Syndrome Gross Motor Scale (maximum score of 45) on five occasions, two during the baseline period and three during the intervention period. Blood levels of BDNF were measured at the two baseline assessments and at the end of the intervention period. The intervention comprised motor learning and exercise supplemented with social, cognitive and other sensory experiences over a six-month period. At the first assessment, the mean (SD) age of the children was 3 years (1 year 1 month) years ranging from 1 year 6 months to 5 years 2 months. Also at baseline, mean (SD) gross motor scores and blood BDNF levels were 22.7/45 (9.6) and 165.0 (28.8) ng/ml respectively. Adjusting for covariates, the enriched environment was associated with improved gross motor skills (coefficient 8.2, 95%CI 5.1, 11.2) and a 321.4 ng/ml (95%CI 272.0, 370.8) increase in blood BDNF levels after 6 months of treatment. Growth, sleep quality and mood were unaffected. Behavioural interventions such as environmental enrichment can reduce the functional deficit in Rett syndrome, contributing to the evidence-base for management and

  12. Lateral Offset of the Volcanic Front: Implications for Fluid Pathways in the Mantle Wedge

    Science.gov (United States)

    Feineman, M. D.; Ryerson, F. J.; Depaolo, D. J.

    2004-12-01

    One of the most striking common features of subduction zones worldwide is the appearance of the volcanic front at a height of approximately 120 km above the subducting slab. The water-rich compositions of the lavas erupted at the volcanic front suggest that melting is initiated by dehydration of hydrous phases in the slab, primarily amphibole. However, the location of the front is offset considerably from the predicted origin of fluids due to amphibole dehydration at ˜80km slab depth. The lateral offset at the surface varies with subduction angle, but generally the predicted site of fluid release is ˜20-70 km trench-ward of the actual volcanic front. Many of the proposed mechanisms for generating this offset involve stalling the fluid in the mantle such that it is drawn down and/or back into the mantle wedge due to viscous flow in the solid mantle. For example, the fluid may re-crystallize as phlogopite and pargasitic amphibole in the portion of the mantle that is viscously coupled to the subducting slab. These newly formed hydrous minerals have higher breakdown pressures than glaucophane, the dominant hydrous mineral in the slab, and could explain the offset to deeper apparent depths of dehydration. However, processes that rely upon solid mantle flow are very slow. For a slab descending at 100mm/yr, 5x105 years are required to descend 40 km vertically ( ˜50 km along-slab). Such long periods of time spent in transport in the mantle are seemingly contradicted by strong U-series isotopic disequilibria in arc lavas. Although special circumstances may be evoked in order to allow U-series disequilibria to be extended in time, it is also possible that reaction rates in the cold descending slab are sluggish to the point that fluids are not released at the expected depth of 80 km, but instead are retained to greater depths where increasing temperatures allow reactions to proceed. In this scenario, the fluids would then be able to proceed relatively quickly to the region

  13. Close-Wedge Osteotomy for Bony Locking Stiffness of the Elbow in Gorham Disease Patients: A Case Report

    Directory of Open Access Journals (Sweden)

    Hsien-Chung Wang

    2004-05-01

    Full Text Available Gorham disease is a so-called massive idiopathic osteolysis or vanishing bone disorder. Massive osteolysis remains an enigmatic condition that involves various skeletal locations and is caused by endothelial proliferation. The diagnosis is difficult and is established via the association of clinical, radiologic and histologic pictures. Treatment modalities yield variable results. We report a case of vanishing bone in the elbow joint and carpal bones following trauma. This 13-year-old boy complained of severe restricted motion and deformity of the right elbow. We managed the problem using arthroplasty with close-wedge osteotomy on the lateral condyle of the humerus.

  14. Erosional Reduction of an Orogenic Wedge: Structural Response to Neogene Climate Change within the St. Elias Orogen, Alaska

    Science.gov (United States)

    Berger, A. L.; Spotila, J. A.; Chapman, J. B.; Pavlis, T. L.; Enkelmann, E.; Buscher, J. T.

    2007-12-01

    The kinematics and architecture of orogenic systems may be heavily influenced by climate, but little research has focused on the long term effects of glacial erosion on orogenesis. Apatite and zircon (U-Th)/He thermochronometry on >75 bedrock samples across the St. Elias orogen, one of the best examples of a glaciated orogenic wedge, is the basis for a new kinematic model and demonstrates an association between glacial denudation and orogenic architecture. The spatial pattern of low temperature cooling indicates that exhumation and deformation are focused within a thin-skinned fold and thrust belt on the windward flank, whereas the leeward flank of the orogen functions as a deformational backstop. A previously unrecognized structure beneath the Bagley ice field must separate these domains with south-side-up motion. We propose this structure is a backthrust making the orogen doubly-vergent. Suggestive of accelerated backthrust motion in response to climate change, cooling rates within the hanging wall block and across the entire windward flank of the orogen accelerated ten-fold coeval with enhanced glaciation. As backthrust motion increased, glacial unroofing also coincided with a regional shift in deformation away from prominent forethrusts including the North American-Yakutat terrane suture (Chugach St. Elias fault) and the seaward deformation front (Pamplona zone). Across the windward flank of the orogen, exhumation, at rates of up to 5 mm/yr, is focused within a narrow zone, where the glacial equilibrium line altitude (ELA) intersects the orogenic wedge. This zone of rapid exhumation, not present prior to the onset of enhanced glaciation, cuts across the structural trend of the orogen and is more narrowly focused than orographic precipitation. Accelerated denudation at the ELA thus appears to have redistributed strain along a series of forethrusts that lie at the zone of heaviest glacial flux, while the backthrust progressively truncates the southward

  15. Effect and Strategy of 1-stage Interrupted 2-level Transpedicular Wedge Osteotomy for Correcting Severe Kyphotic Deformities in Ankylosing Spondylitis.

    Science.gov (United States)

    Zhao, Yongfei; Wang, Yan; Wang, Zheng; Zhang, Xuesong; Mao, Keya; Zhang, Yonggang

    2017-05-01

    Prospective study. To investigate the safety, outcome, and strategy of the 1-stage interrupted 2-level transpedicular wedge osteotomy for correcting the severe kyphotic deformity in ankylosing spondylitis (AS). There has been a large series in the literature reporting on results of osteotomy for the correction of kyphotic deformity secondary to AS. However, few articles have reported, in detail, the plan, design, strategy, and effect of 1-stage interrupted 2-level transpedicular wedge osteotomy for the correction of severe kyphotic deformity in AS. From May 2003 to February 2010, 24 consecutive patients, 17 males and 7 females, suffering from AS with severe spinal kyphosis, underwent 1-stage interrupted 2-level transpedicular wedge osteotomy in our hospital by the corresponding author. Improvements in relevant parameters were recorded and clinical results were evaluated. The average operating time was 282±43 minutes, and the average blood loss was 2202±737 mL. All the global and regional spinal alignments improved to relatively normal status: the global thoracolumbar kyphosis angle improved from 101.5±10.8 to 24.8±5.8 degrees (P<0.001), the thoracolumbar kyphosis improved from 37.9±5.1 to 0.7±12.8 degrees (P<0.001), and the lumbar lordosis improved from 35.0±9.2 to -25.7±10.9 degrees (P<0.001). Meanwhile, the chin-brow vertical angle improved from 79.5±5.1 to 8.5±2.7 degrees (P<0.001), and the sagittal imbalance distance improved from 49.6±6.5 to 11.5±3.5 cm (P<0.001). All the patients could walk with horizontal vision and lie on their backs postoperatively, and scoliosis research society-22 scores improved from 1.6±0.2 preoperatively to 4.3±0.2 at the 2-year follow-up. The mean time of follow-up was 52±28 months. Fusion of the osteotomy was achieved in each patient and no instances of loss of correction or implant failure were noted. For correcting severe kyphosis in patients with AS, the 1-stage interrupted 2-level transpedicular wedge osteotomy is

  16. Structure and tectonic evolution of the southwestern Trinidad dome, Escambray complex, Central Cuba: Insights into deformation in an accretionary wedge

    Science.gov (United States)

    Despaigne-Díaz, Ana Ibis; García Casco, Antonio; Cáceres Govea, Dámaso; Wilde, Simon A.; Millán Trujillo, Guillermo

    2017-10-01

    The Trinidad dome, Escambray complex, Cuba, forms part of an accretionary wedge built during intra-oceanic subduction in the Caribbean from the Late Cretaceous to Cenozoic. The structure reflects syn-subduction exhumation during thickening of the wedge, followed by extension. Field mapping, metamorphic and structural analysis constrain the tectonic evolution into five stages. Three ductile deformation events (D1, D2 and D3) are related to metamorphism in a compressional setting and formation of several nappes. D1 subduction fabrics are only preserved as relict S1 foliation and rootless isoclinal folds strongly overprinted by the main S2 foliation. The S2 foliation is parallel to sheared serpentinised lenses that define tectonic contacts, suggesting thrust stacks and underthrusting at mantle depths. Thrusting caused an inverted metamorphic structure with higher-grade on top of lower-grade nappes. Exhumation started during D2 when the units were incorporated into the growing accretionary wedge along NNE-directed thrust faults and was accompanied by substantial decompression and cooling. Folding and thrusting continued during D3 and marks the transition from ductile to brittle-ductile conditions at shallower crustal levels. The D4-5 events are related to extension and contributed to the final exhumation (likely as a core complex). D4 is associated with a regional spaced S4 cleavage, late open folds, and numerous extension veins, whereas D5 is recorded by normal and strike-slip faults affecting all nappes. The P-t path shows rapid exhumation during D2 and slower rates during D3 when the units were progressively incorporated into the accretionary prism. The domal shape formed in response to tectonic denudation assisted by normal faulting and erosion at the surface during the final stages of structural development. These results support tectonic models of SW subduction of the Proto-Caribbean crust under the Caribbean plate during the latest Cretaceous and provide

  17. Wedge Splitting Test and Inverse Analysis on Fracture Behaviour of Fiber Reinforced and Regular High Performance Concretes

    DEFF Research Database (Denmark)

    Hodicky, Kamil; Hulin, Thomas; Schmidt, Jacob Wittrup

    2014-01-01

    that the refinement of the softening curves reflects in improved accuracy of the WST (wedge splitting test) simulation in comparison with bi-linear softening curves with acceptable increase of computational time. Furthermore, the fracture mechanics parameters such as COD (crack opening displacement), fracture energy...... was used experimentally and the cracked non-linear hinge model based on the fictitious crack model was applied for the interpretation of the results. The stress-crack opening relationships were extracted by using inverse analysis algorithm for various multi-linear softening curves. This showed...

  18. Stem thrust prediction model for Westinghouse wedge gate valves with linkage type stem-to-disk connection

    Energy Technology Data Exchange (ETDEWEB)

    Wang, J.K.; Sharma, V.; Kalsi, M.S. [Kalsi Engineering, Inc., Sugar Land, TX (United States)] [and others

    1996-12-01

    The Electric Power Research Institute (EPRI) conducted a comprehensive research program with the objective of providing nuclear utilities with analytical methods to predict motor operated valve (MOV) performance under design basis conditions. This paper describes the stem thrust calculation model developed for evaluating the performance of one such valve, the Westinghouse flexible wedge gate valve. These procedures account for the unique functional characteristics of this valve design. In addition, model results are compared to available flow loop and in situ test data as a basis for evaluating the performance of the valve model.

  19. Influence of mantle viscosity structure and mineral grain size on fluid migration pathways in the mantle wedge.

    Science.gov (United States)

    Cerpa, N. G.; Wada, I.; Wilson, C. R.; Spiegelman, M. W.

    2016-12-01

    We develop a 2D numerical porous flow model that incorporates both grain size distribution and matrix compaction to explore the fluid migration (FM) pathways in the mantle wedge. Melt generation for arc volcanism is thought to be triggered by slab-derived fluids that migrate into the hot overlying mantle and reduce its melting temperature. While the narrow location of the arcs relative to the top of the slab ( 100±30 km) is a robust observation, the release of fluids is predicted to occur over a wide range of depth. Reconciling such observations and predictions remains a challenge for the geodynamic community. Fluid transport by porous flow depends on the permeability of the medium which in turn depends on fluid fraction and mineral grain size. The grain size distribution in the mantle wedge predicted by laboratory derived laws was found to be a possible mechanism to focusing of fluids beneath the arcs [Wada and Behn, 2015]. The viscous resistance of the matrix to the volumetric strain generates compaction pressure that affects fluid flow and can also focus fluids towards the arc [Wilson et al, 2014]. We thus have developed a 2D one-way coupled Darcy's-Stokes flow model (solid flow independent of fluid flow) for the mantle wedge that combines both effects. For the solid flow calculation, we use a kinematic-dynamic approach where the system is driven by the prescribed slab velocity. The solid rheology accounts for both dislocation and diffusion creep and we calculate the grain size distribution following Wada and Behn [2015]. In our fluid flow model, the permeability of the medium is grain size dependent and the matrix bulk viscosity depends on solid shear viscosity and fluid fraction. The fluid influx from the slab is imposed as a boundary condition at the base of the mantle wedge. We solve the discretized governing equations using the software package TerraFERMA. Applying a range of model parameter values, including slab age, slab dip, subduction rate, and fluid

  20. SU-E-T-562: Scanned Percent Depth Dose Curve Discrepancy for Photon Beams with Physical Wedge in Place (Varian IX) Using Different Sensitive Volume Ion Chambers

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, H; Sarkar, V; Rassiah-Szegedi, P; Huang, Y; Szegedi, M; Huang, L; Salter, B [University Utah, Salt Lake City, UT (United States)

    2014-06-01

    Purpose: To investigate and report the discrepancy of scanned percent depth dose (PDD) for photon beams with physical wedge in place when using ion chambers with different sensitive volumes. Methods/Materials: PDD curves of open fields and physical wedged fields (15, 30, 45, and 60 degree wedge) were scanned for photon beams (6MV and 10MV, Varian iX) with field size of 5x5 and 10x10 cm using three common scanning chambers with different sensitive volumes - PTW30013 (0.6cm3), PTW23323 (0.1cm3) and Exradin A16 (0.007cm3). The scanning system software used was OmniPro version 6.2, and the scanning water tank was the Scanditronix Wellhoffer RFA 300.The PDD curves from the three chambers were compared. Results: Scanned PDD curves of the same energy beams for open fields were almost identical between three chambers, but the wedged fields showed non-trivial differences. The largest differences were observed between chamber PTW30013 and Exradin A16. The differences increased as physical wedge angle increased. The differences also increased with depth, and were more pronounced for 6MV beam. Similar patterns were shown for both 5x5 and 10x10 cm field sizes. For open fields, all PDD values agreed with each other within 1% at 10cm depth and within 1.62% at 20 cm depth. For wedged fields, the difference of PDD values between PTW30013 and A16 reached 4.09% at 10cm depth, and 5.97% at 20 cm depth for 6MV with 60 degree physical wedge. Conclusion: We observed a significant difference in scanned PDD curves of photon beams with physical wedge in place obtained when using different sensitive volume ion chambers. The PDD curves scanned with the smallest sensitive volume ion chamber showed significant difference from larger chamber results, beyond 10cm depth. We believe this to be caused by varying response to beam hardening by the wedges.

  1. The use of a lateral wedge insole to reduce knee loading when ascending and descending stairs in medial knee osteoarthritis patients.

    Science.gov (United States)

    Alshawabka, Amneh Z; Liu, Anmin; Tyson, Sarah F; Jones, Richard K

    2014-06-01

    Stair climbing is a challenging task to the elderly being the task with the first complaint in patients with mild to moderate knee osteoarthritis. Stair climbing results in around six times more compressive load transmitted through the knee joint than walking on level ground. The purpose of this study was to assess whether lateral wedge insoles would reduce medial compartment knee loading when ascending and descending stairs in patients with medial knee osteoarthritis. Eight patients with medial knee osteoarthritis were tested in random order with and without a pair of 5° off-the-shelf lateral wedge insoles for two separate activities (stair ascent and stair descent). Kinematic and kinetic data were collected for the lower extremity using a sixteen camera motion capture system and two force plates. Primary outcome measures were the external knee adduction moment and the knee adduction angular impulse. During stair ascent and descent, lateral wedge insoles significantly (Pstairs, lateral wedge insoles consistently reduced the overall magnitude of medial compartment loading during stair ascent and descent. Further research is needed to determine the relationship of this with clinical results when ascending and descending stairs with lateral wedge insoles. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Applications of Diamonded Double Negation

    OpenAIRE

    Yli-Jyrä, Anssi

    2008-01-01

    Nested complementation plays an important role in expressing counter- i.e. star-free and first-order definable languages and their hierarchies. In addition, methods that compile phonological rules into finite-state networks use double-nested complementation or “double negation”. This paper reviews how the double-nested complementation extends to a relatively new operation, generalized restriction (GR), coined by the author (Yli-Jyrä and Koskenniemi 2004). This operation encapsulates a double-...

  3. Double Cortex Syndrome

    OpenAIRE

    J Gordon Millichap

    1999-01-01

    The incidence of mutations in the X-linked gene doublecortin in patients with “double cortex” syndrome (DC; also called subcortical band heterotopia or laminar heterotopia) and familial DC with lissencephaly was investigated in a cohort of 8 pedigrees and 47 sporadic patients with DC examined at the Division of Neurogenics, Beth Israel Deaconess Medical Center, Boston, and multiple centers in the US and abroad.

  4. Algebra of Majorana doubling.

    Science.gov (United States)

    Lee, Jaehoon; Wilczek, Frank

    2013-11-27

    Motivated by the problem of identifying Majorana mode operators at junctions, we analyze a basic algebraic structure leading to a doubled spectrum. For general (nonlinear) interactions the emergent mode creation operator is highly nonlinear in the original effective mode operators, and therefore also in the underlying electron creation and destruction operators. This phenomenon could open up new possibilities for controlled dynamical manipulation of the modes. We briefly compare and contrast related issues in the Pfaffian quantum Hall state.

  5. Results of double contrast enema

    Energy Technology Data Exchange (ETDEWEB)

    Czembirek, H.; Sommer, G.; Wittich, G.; Tscholakoff, D.; Salomonowitz, E.

    1983-07-01

    Experiences and results of double contrast enemas are reported. The accuracy of double contrast enemas is proved by 500 consecutive investigations. Correlation of endoscopic and roentgenologic investigations showed, that the double contrast enema is a reliable method concerning the detection of polyps, carcinomas and inflammatory colon diseases. Advantages and disadvantages of roentgenology and endoscopy of the colon are discussed.

  6. Investigation of Boundary Effects on the Natural Cavitating Flow around a 2D Wedge in Shallow Water

    Directory of Open Access Journals (Sweden)

    Xin Chen

    2011-01-01

    Full Text Available When a cavitated body moves in shallow water, both flexible free surface and rigid bottom wall will produce great influence on the cavity pattern and hydrodynamics to change the motion attitude and stability of the body. In this paper, a single-fluid multiphase flow method coupled with a natural cavitation model was employed to study the effects of two kinds of boundaries on the natural cavitating flow around a two-dimensional symmetry wedge in shallow water. Within the range of the cavitation number for computation (0.05 ~ 2.04, the cavity pattern would be divided into three types, namely, stable type, transition type and wake-vortex type. The shape of the free surface is fairly similar to that of the cavity's upper surface with well right-and-left symmetry. However, when the immersion depth and the cavitation number are decreasing, the symmetry of the cavity shape is destroyed due to the influence of bottom wall effects. When the cavitation number is less than about 0.1, with the immersion depth going down, free surface effects exerts a stronger influence on the drag coefficient of this 2D wedge, whereas wall effects bring a stronger influence on the lift coefficient.

  7. On sound scattering by rigid edges and wedges in a flow, with applications to high-lift device aeroacoustics

    Science.gov (United States)

    Roger, Michel; Moreau, Stéphane; Kucukcoskun, Korcan

    2016-02-01

    Exact analytical solutions for the scattering of sound by the edge of a rigid half-plane and by a rigid corner in the presence of a uniform flow are considered in this work, for arbitrary source and observer locations. Exact Green's functions for the Helmholtz equation are first reviewed and implemented in a quiescent propagation space from reference expressions of the literature. The effect of uniform fluid motion is introduced in a second step and the properties of the field are discussed for point dipoles and quadrupoles. The asymptotic regime of a source close to the scattering edge/wedge and of an observer far from it in terms of acoustic wavelengths is derived in both cases. Its validity limits are assessed by comparing with the exact solutions. Typically the asymptotic directivity is imposed by Green's function but not by the source itself. This behaviour is associated with a strong enhancement of the radiation with respect to what the source would produce in free field. The amplification depends on the geometry, on the source type and on the source distance to the edge/wedge. Various applications in aeroacoustics of wall-bounded flows are addressed, more specifically dealing with high-lift device noise mechanisms, such as trailing-edge or flap side-edge noise. The asymptotic developments are used to highlight trends that are believed to play a role in airframe noise.

  8. Miocene thrusting in the eastern Sila Massif: Implication for the evolution of the Calabria-Peloritani orogenic wedge (southern Italy)

    Science.gov (United States)

    Vignaroli, G.; Minelli, L.; Rossetti, F.; Balestrieri, M. L.; Faccenna, C.

    2012-05-01

    Alpine orogens in the central Mediterranean region have revealed the concomitance of crustal extension in back-arc domain and crustal shortening in frontal domain. Quantitative data of deformation in the frontal orogenic wedges are necessary to understand how the shortening-extension pair evolves in terms of structures, orogenic transport, timing, and exhumation rate. This paper deals with kinematics and ages of the frontal thrust systems of the Calabria-Peloritani Arc (Italy) exposed in the eastern Sila Massif. We first present structural fieldwork, onshore and offshore well log data, and new apatite fission-track (AFT) thermochronology. Then, we describe the structural architecture of the studied area as an ENE-verging stacking of thrust sheets involving basement units and syn-orogenic sediments. The AFT study documents that thrust sheets entered the partial annealing zone from 18 Ma to 13 Ma. This Early-Middle Miocene thrusting phase was coeval with exhumation of high-pressure/low temperature metamorphic rocks in the hinterland of the orogen (Coastal Chain area), mainly driven by top-to-the-W extensional tectonics. Opposite kinematic shear senses (contractional top-to-the-E and extensional top-to-the-W) and different exhumation rates (slow in the frontal, more rapid in the hinterland) are framed in a tectonic scenario of a critically tapered orogenic wedge during the eastward retreating of the Apennine slab.

  9. Evaluation of the use of very high resolution aerial imagery for accurate ice-wedge polygon mapping (Adventdalen, Svalbard).

    Science.gov (United States)

    Lousada, Maura; Pina, Pedro; Vieira, Gonçalo; Bandeira, Lourenço; Mora, Carla

    2017-09-24

    The main objective of this paper is to verify the accuracy of delineating and characterizing ice-wedge polygonal networks with features exclusively extracted from remotely sensed images of very high resolution. This kind of mapping plays a key role for quantifying ice-wedge degradation in warming permafrost. The evaluation of mapping a network is performed in this study with two sets of aerial images that are compared to ground reference data determined by fieldwork on the same network, located in Adventdalen, Svalbard (78°N). One aerial dataset is obtained from a photogrammetric survey with RGB+NIR imagery of 20cm/pixel, the other from an UAV (Unmanned Aerial Vehicle) survey that acquired RGB images of 6cm/pixel of spatial resolution. Besides evaluating the degree of matching between the delineations, the morphometric and topological features computed for the differently mapped versions of the network are also confronted, to have a more solid basis of comparison. The results obtained are similar enough to admit that remotely sensed images of very high resolution are an adequate support to provide extensive characterizations and classifications of this kind of patterned ground. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Landsliding generated by thermomechanical interactions between rock columns and wedging blocks: Study case from the Larzac Plateau (Southern France)

    Science.gov (United States)

    Taboada, Alfredo; Ginouvez, Hadrien; Renouf, Mathieu; Azemard, Pierre

    2017-06-01

    The Larzac Plateau is delimited by vertical cliffs whose geometry is controlled by vertical joints. Cliff's erosion involves landslides initiated by incremental enlargement of joints that progressively detach rock columns at very low velocities (1.2 mm/yr). We find that enlargement of joints is linked to intraseasonal thermal cycles ranging between 2-15 days in relation with dilation/contraction of rock blocks trapped inside the joints. The mechanism involves two successive stages in which blocks create a wedging and a ratcheting effect on the rock column. Wedging is associated with compressional forces acting on the rock column, resulting from temperature increase and dilation of the shallow rocks. Ratcheting is associated with downward displacement of blocks by gravity to a new equilibrium position, resulting from temperature decrease and contraction of shallow rocks. The displacement vector in a thermal cycle is split into a plastic and a thermal component; plastic displacements range between 10 — 200 μm according to the seasons, and are absorbed along a shear plane dipping 40° beneath the rock column: they are largest during autumn and winter, minor during spring and negligible in summer. This deformation mechanism is termed thermomechanical creep as permanent deformations are associated to mechanical forces induced by short-term thermal cycles.

  11. An evaluation of factors influencing pore pressure in accretionary complexes: Implications for taper angle and wedge mechanics

    Science.gov (United States)

    Saffer, D.M.; Bekins, B.A.

    2006-01-01

    At many subduction zones, accretionary complexes form as sediment is off-scraped from the subducting plate. Mechanical models that treat accretionary complexes as critically tapered wedges of sediment demonstrate that pore pressure controls their taper angle by modifying basal and internal shear strength. Here, we combine a numerical model of groundwater flow with critical taper theory to quantify the effects of sediment and de??collement permeability, sediment thickness, sediment partitioning between accretion and underthrusting, and plate convergence rate on steady state pore pressure. Our results show that pore pressure in accretionary wedges can be viewed as a dynamically maintained response to factors which drive pore pressure (source terms) and those that limit flow (permeability and drainage path length). We find that sediment permeability and incoming sediment thickness are the most important factors, whereas fault permeability and the partitioning of sediment have a small effect. For our base case model scenario, as sediment permeability is increased, pore pressure decreases from near-lithostatic to hydrostatic values and allows stable taper angles to increase from ??? 2.5?? to 8??-12.5??. With increased sediment thickness in our models (from 100 to 8000 m), increased pore pressure drives a decrease in stable taper angle from 8.4??-12.5?? to 15?? to influence the strength of the crust in a wide range of geologic settings. Copyright 2006 by the American Geophysical Union.

  12. Robotic device-assisted knee extension training during the early postoperative period after opening wedge high tibial osteotomy: a case report.

    Science.gov (United States)

    Yoshioka, Tomokazu; Kubota, Shigeki; Sugaya, Hisashi; Hyodo, Kojiro; Ogawa, Kaishi; Taniguchi, Yu; Kanamori, Akihiro; Sankai, Yoshiyuki; Yamazaki, Masashi

    2017-08-05

    Maintenance or restoration of a good range of motion of the knee is one of the most important outcomes following knee surgery. According to previous studies, opening wedge high tibial osteotomy enables better recovery of range of motion in knee flexion than that achievable after total knee arthroplasty or unicompartmental knee arthroplasty. However, few reports provide a detailed description of the postoperative recovery of knee extension range of motion after opening wedge high tibial osteotomy. We describe our experience with a knee extension training program using a single-joint hybrid assistive limb device (HAL-SJ; Cyberdyne Inc., Tsukuba, Japan) during the acute recovery phase after opening wedge high tibial osteotomy. The HAL-SJ is a wearable robotic device that facilitates voluntary control of knee joint motion. A 67-year-old Japanese woman who underwent opening wedge high tibial osteotomy for spontaneous osteonecrosis of the left medial femoral condyle received HAL-SJ-based knee extension training postoperatively. Our experience with this patient revealed that knee extension training with the HAL-SJ during the acute phase following opening wedge high tibial osteotomy is feasible. Furthermore, the patient's knee extension range of motion improved to values similar to those seen during the preoperative stage, and her flexion range of motion was improved at 3 months after the surgery. HAL-SJ-based knee extension training could be used as a novel post-opening wedge high tibial osteotomy rehabilitation modality. Further exploration of individualized optimal settings of the HAL-SJ is required to improve its safety and efficacy.

  13. Ac-induced disruption of the doubleDs structure in tomato

    NARCIS (Netherlands)

    Rommens, Caius M.T.; Biezen, Erik A. van der; Ouwerkerk, Pieter B.F.; Nijkamp, H. John J.; Hille, Jacques

    1991-01-01

    The maize doubleDs element is stably maintained in the tomato genome. Upon the subsequent introduction of Ac into a plant containing doubleDs, disruption of the doubleDs structure and DNA rearrangements at the site of the doubleDs element were observed. No indications were obtained for excision of

  14. Evidence of focused fluid flow associated to the gas hydrate wedge on the angolan margin

    Science.gov (United States)

    Casenave, Viviane; Imbert, Patrice; Gay, Aurélien

    2013-04-01

    The Lower Congo basin, offshore south west Africa, is a prolific petroleum province, which has been extensively investigated and exploited for more than 30 years. The study area is located above a producing oil and gas field, the hydrocarbons being trapped in turbidite channels on a tectonic horst. The work is based on the analysis of 3-D seismic and site survey data (2D AUV, grab samples and ROV photos) above a deeper oil and gas field called Moho. The analysis of this seismic data set reveals numerous evidence of focused fluid flow through the Mio-Pliocene interval, including present-day seafloor seep features and shallow buried paleo-seeps, indicating past activity of the system. The main fluid migration-related structures are the followings: 1. Stacked amplitude anomalies, interpreted as the result of vertical migrations of gas are pervasive. Most of these seep features seem to correspond to fossil events as they are interpreted as successive precipitation at the seafloor of patches of seep carbonates (MDAC, Methane Derived Authigenic Carbonates) stacked during the activity of a seep. 2. Another phenomenon of gas migration through the sediment pile is visible on the seismic data of the Moho area: it is the BSR (Bottom Simulating Reflector) located above a horst. The BSR is formed by 2 patches, which cover a small area about 1.5 km² for the largest and 0.5 km2 for the smallest. These two BSRs are located under a depth of water included between 600 and 700 m, into the BSR wedging area. 3. A 'spider morphology' is visible on the seafloor. It corresponds to depressions forming variable-sized furrows oriented slightly oblique to the slope dip direction, directly above the upslope limit of the BSR patches. ROV photos and movies from these furrows showed the presence of seep carbonates and of bacterial carpets, linked with methane leak at the seafloor. A similar 'spider morphology' was also identified in subsurface, at 20 ms under the seafloor, further down the slope

  15. Geometrical determinations of IMRT photon pencil-beam path in radiotherapy wedges and limit divergence angle with the Anisotropic Analytic Algorithm (AAA

    Directory of Open Access Journals (Sweden)

    Francisco Casesnoves

    2014-08-01

    Full Text Available Purpose: Static wedge filters (WF are commonly used in radiation therapy, forward and/or inverse planning. We calculated the exact 2D/3D geometrical pathway of the photon-beam through the usual alloy WF, in order to get a better dose related to the beam intensity attenuation factor(s, after the beam has passed through the WF. The objective was to provide general formulation into the Anisotropic Analytical Algorithm (AAA model coordinates system (depending on collimator/wedge angles that also can be applied to other models. Additionally, second purpose of this study was to develop integral formulation for 3D wedge exponential factor with statistical approximations, with introduction for the limit angle/conformal wedge.Methods: The radiotherapy model used to develop this mathematical task is the classical superposition-convolution algorithm, AAA (developed by Ulmer and Harder. We worked with optimal geometrical approximations to make the computational IMRT calculations quicker/reduce the planning-system time. Analytic geometry/computational-techniques to carry out simulations (for standard wedges are detailed/developed sharply. Integral developments/integral-statistical approximations are explained. Beam-divergence limit Angle for optimal wedge filtration formulas is calculated/sketched, with geometrical approximations. Fundamental trigonometry is used for this purpose.Results: Extent simulation tables for WF of 15º, 30º, 45º, and 60º are shown with errors. As a result, it is possible to determine the best individual treatment dose distribution for each patient. We presented these basic simulations/numerical examples for standard manufacturing WF of straight sloping surface, to check the accuracy/errors of the calculations. Simulations results give low RMS/Relative Error values (formulated for WF of 15º, 30º, 45º, and 60º.Conclusion: We obtained a series of formulas of analytic geometry for WF that can be applied for any particular dose

  16. Terahertz emission from pie-shaped wedge microstrip antennas of the high-Tc superconductor Bi2Sr2CaCu2O8+δ

    Science.gov (United States)

    Wang, Qing; Doty, Constance; Klemm, Richard; Delfanazari, Kaveh; Cerkoney, Daniel; Yamamoto, Takashi; Tsujimoto, Manabu; Kadowaki, Kazuo; Watanabe, Chiharu; Minami, Hidetoshi; Kashiwagi, Takanari; Morales, Manuel

    We calculate the standing wave functions for pie-shaped wedge microstrip antennas of various wedge angles ϕ0. We then calculate the emission distributions from the uniform Josephson current and from the excitation of a cavity mode generated from the stand wave functions. For a narrow dieter's pie slice, quantitative fits to the experimental data on a Bi2Sr2CaCu2O8+δ narrow isosceles triangular mesa are shown. supported in part by a JSPS Research Fellowship, and by CREST-JST and WPI-MANA.

  17. The Double Star mission

    Directory of Open Access Journals (Sweden)

    Liu

    2005-11-01

    Full Text Available The Double Star Programme (DSP was first proposed by China in March, 1997 at the Fragrant Hill Workshop on Space Science, Beijing, organized by the Chinese Academy of Science. It is the first mission in collaboration between China and ESA. The mission is made of two spacecraft to investigate the magnetospheric global processes and their response to the interplanetary disturbances in conjunction with the Cluster mission. The first spacecraft, TC-1 (Tan Ce means "Explorer", was launched on 29 December 2003, and the second one, TC-2, on 25 July 2004 on board two Chinese Long March 2C rockets. TC-1 was injected in an equatorial orbit of 570x79000 km altitude with a 28° inclination and TC-2 in a polar orbit of 560x38000 km altitude. The orbits have been designed to complement the Cluster mission by maximizing the time when both Cluster and Double Star are in the same scientific regions. The two missions allow simultaneous observations of the Earth magnetosphere from six points in space. To facilitate the comparison of data, half of the Double Star payload is made of spare or duplicates of the Cluster instruments; the other half is made of Chinese instruments. The science operations are coordinated by the Chinese DSP Scientific Operations Centre (DSOC in Beijing and the European Payload Operations Service (EPOS at RAL, UK. The spacecraft and ground segment operations are performed by the DSP Operations and Management Centre (DOMC and DSOC in China, using three ground station, in Beijing, Shanghai and Villafranca.

  18. Layered double hydroxides

    DEFF Research Database (Denmark)

    López Rayo, Sandra; Imran, Ahmad; Hansen, Hans Chr. Bruun

    2017-01-01

    A novel zinc (Zn) fertilizer concept based on Zn doped layered double hydroxides (Zn-doped Mg-Fe-LDHs) has been investigated. Zn-doped Mg-Fe-LDHs were synthetized, their chemical composition was analyzed and their nutrient release was studied in buffered solutions with different pH values. Uptake...... the long-term Zn release capacity of LDHs complying with a release-on-demand behavior and serves as proof-of-concept that Zn-doped Mg-Fe-LDHs can be used as Zn fertilizers....

  19. Quality control of virtual wedge in a linear electron accelerator with a computerized radiography system (CR); Control de calidad de la cuna virtual en un acelerador lineal de electrones mediante un sistema de radiografia competerizada (CR)

    Energy Technology Data Exchange (ETDEWEB)

    Ordiales, J. M.; Alvarez, F. J.; Falero, B.

    2011-07-01

    For quality control of the virtual wedge there are several systems on the market as arrays of detectors or ionization chambers, linear or 2D configuration, radiochromic films or digital imaging systems incorporated in electron linear accelerators (ALE ). The present work aims at implementing a system of Computed Radiography (CR) for a routine check of the virtual wedge.

  20. Checks for quality control of wedge dynamics in treatment units and the planning system; Verificaciones para control de calidad de la cuna dinamica en las unidades de tratamiento y el sistema de planificacion

    Energy Technology Data Exchange (ETDEWEB)

    Mateos Salvador, P.; Rodriguez Lopez, B.; Font Gelabert, J.; Hernandez Rodriguez, J.; Arino Gil, A.

    2013-07-01

    The objective of this study is to verify the implementation of enhanced dynamic wedge (EDW) vary in the Eclipse planning system and the experimental determination of the parameters that define the dosimetry characteristics of enhanced dynamic wedge of our treatment units. (Author)

  1. Double conjugate laser amplifier

    Energy Technology Data Exchange (ETDEWEB)

    Chandra, S.; Daunt, G.H.

    1991-01-29

    This paper describes a double conjugate laser amplifier system for producing a stable output laser beam in line with a laser oscillator input beam. It comprises: a laser oscillator which produces a low energy oscillator laser beam therefrom directly along a laser beam axis of the system; an amplification means comprised of double conjugate laser amplifiers further comprised of a first and a second singly phase conjugate amplifiers laterally opposite each other about the laser beam axis; polarizers with one of the polarizers positioned between each of the first and second singly phase conjugate amplifiers on the laser beam axis; Pockels cells with on of the Pockels cells positioned on the laser beam axis immediately prior to one of the polarizers; and a means for selectively switching the amplifier means comprised of applying a half-wave voltage at each of the Pockels cells to provide a polarization rotation of the input beam through 90{degrees} for routing of the oscillator laser beam directly through or reflected off the polarizes as an input beam to the amplification means wherein the amplification means amplifies the input beam twice in each of the first and second singly phase conjugate amplifiers and reflects the amplified laser beam off the polarizers as an amplified laser output beam in exactly the same direction as the input laser beam.

  2. Double First Metatarsal and Akin Osteotomy for Severe Hallux Valgus.

    Science.gov (United States)

    Al-Nammari, Shafic Said; Christofi, Theodoros; Clark, Callum

    2015-10-01

    The technique of double first metatarsal osteotomies was first developed in response to the high frequency of recurrence noted in the treatment of severe adolescent congruent hallux valgus deformities. The concept behind the use of this technique is that it allows the individual correction of each component of the deformity. We have modified the technique for use in adult hallux valgus where the majority of deformities are incongruent deformities and the distal chevron osteotomy is used primarily for its additional translational properties rather than purely to correct the distal metatarsal articular angle (DMAA). We report on a series of double first metatarsal osteotomies (basal opening wedge and distal chevron osteotomy) with Akin osteotomy in the treatment of moderate to severe adult hallux valgus deformity. All patients presenting to our institution with a hallux valgus deformity and treated with this procedure between 2008 and 2013 with a minimum of 1 year of follow-up were identified. Data were obtained through review of case notes, electronic charts, and digital imaging. A total of 50 feet in 48 patients underwent double first metatarsal osteotomy with Akin osteotomy. Three patients were excluded due to loss to follow-up, leaving 47 feet in 45 patients with a mean follow-up of 45 months (range, 14-60 months). Of these 43 (96%) were female and the mean age was 56 years (range, 35-70 years). The mean preoperative hallux valgus angle (HVA), intermetatarsal angle (IMA), DMAA, sesamoid position, and lateral first metatarsotalar angle were 42 degrees (range, 32-52 degrees), 18 degrees (range, 6-26 degrees), 12 degrees (range, 4-26 degrees), stage 6 (range, 4-7), and 2 degrees of dorsiflexion (range, 20 degrees of dorsiflexion to 4 degrees of plantar flexion), respectively. The mean postoperative HVA, IMA, DMAA, sesamoid position, and lateral first metatarsotalar angle were 7 degrees (range, 2 to 24 degrees), 4 degrees (range, 4-14 degrees), 6 degrees (range, 10

  3. Firsthand in situ observation of active fine laser tuning by combining a temperature gradient and a CLC wedge cell structure.

    Science.gov (United States)

    Jeong, Mi-Yun; Cha, Jihun

    2015-08-10

    In situ direct observation of the lasing process in a cholesteric liquid crystal (CLC) laser array using a CMOS camera was used to investigate discontinuous laser tuning in a parallel CLC cell. In accordance with the discontinuous pitch change by thermal energy transfer, at the same time the laser wavelength undergoes an immediate and discontinuous shift. And we found out the reason why the CLC phase has domain textures. And this work develops a simple active tunable laser array by forming a spatial temperature gradient along a wedge CLC cell. With this new strategy, only just about 7 nm laser tuning range at room temperature is extremely widened over the 105 nm wavelength range with about 0.2 nm tuning resolution. Furthermore, there is no aging effect because the employed CLC array has only one chiral molecular concentration. This strategy could be used in a practical CLC laser device application.

  4. Mixed convection boundary layer flows of a non-Newtonian Jeffrey’s fluid from a non-isothermal wedge

    Directory of Open Access Journals (Sweden)

    S. Abdul Gaffar

    2017-06-01

    Full Text Available This article presents the nonlinear, steady state mixed convection boundary layer flow, heat and mass transfer of an incompressible non-Newtonian Jeffrey’s fluid past a non-isothermal wedge. The transformed conservation equations are solved numerically subject to physically appropriate boundary conditions using a versatile, implicit finite-difference Keller box technique. The influence of a number of emerging non-dimensional parameters, namely Deborah number (De, ratio of relaxation to retardation times (λ, pressure gradient parameter (m, Buoyancy ratio parameter (N, mixed convection parameter (λ1, radiation parameter (F and heat generation/absorption parameter (Δ on velocity, temperature and concentration evolution in the boundary layer regime is examined in detail. Also, the effects of these parameters on surface heat transfer rate, mass transfer rate and local skin friction are investigated.

  5. Open-wedge osteotomy using an internal plate fixator in patients with medial-compartment gonarthritis and varus malalignment

    DEFF Research Database (Denmark)

    Niemeyer, Philipp; Schmal, Hagen; Hauschild, Oliver

    2010-01-01

    are correlated with arthroscopic and radiographic findings at the time of surgery. METHODS: This study included 69 patients with a minimum follow-up of 36 months who underwent open-wedge HTO for medial-compartment osteoarthritis of the knee. Knee function was assessed before surgery and at 6, 12, 24, and 36...... continuous increase in International Knee Documentation Committee score from 47.25 ± 18.71 points before surgery to 72.72 ± 17.15 points at 36 months after HTO was found (P Grade of cartilage damage of the medial compartment and partial-thickness defects of the lateral compartment did...... not significantly influence clinical outcome (P > .05 at all time points). The tibial bone varus angle was correlated significantly with greater improvement and better clinical outcome after HTO (P related to surgical causes; nevertheless, a high proportion...

  6. Impact of thermal radiation on MHD slip flow of a ferrofluid over a non-isothermal wedge

    Energy Technology Data Exchange (ETDEWEB)

    Rashad, A.M.

    2017-01-15

    This article is concerned with the problem of magnetohydrodynamic (MHD) mixed convection flow of Cobalt-kerosene ferrofluid adjacent a non-isothermal wedge under the influence of thermal radiation and partial slip. Such type of problems are posed by electric generators and biomedical enforcement. The governing equations are solved using the Thomas algorithm with finite-difference type and solutions for a wide range of magnet parameter are presented. It is found that local Nusselt number manifests a considerable diminishing for magnetic parameter and magnifies intensively in case of slip factor, thermal radiation and surface temperature parameters. Further, the skin friction coefficient visualizes a sufficient enhancement for the parameters thermal radiation, surface temperature and magnetic field, but a huge reduction is recorded by promoting the slip factor.

  7. Hard-sphere fluid adsorbed in an annular wedge: the depletion force of hard-body colloidal physics.

    Science.gov (United States)

    Herring, A R; Henderson, J R

    2007-01-01

    Many important issues of colloidal physics can be expressed in the context of inhomogeneous fluid phenomena. When two large colloids approach one another in solvent, they interact at least partly by the response of the solvent to finding itself adsorbed in the annular wedge formed between the two colloids. At shortest range, this fluid mediated interaction is known as the depletion force/interaction because solvent is squeezed out of the wedge when the colloids approach closer than the diameter of a solvent molecule. An equivalent situation arises when a single colloid approaches a substrate/wall. Accurate treatment of this interaction is essential for any theory developed to model the phase diagrams of homogeneous and inhomogeneous colloidal systems. The aim of our paper is a test of whether or not we possess sufficient knowledge of statistical mechanics that can be trusted when applied to systems of large size asymmetry and the depletion force in particular. When the colloid particles are much larger than a solvent diameter, the depletion force is dominated by the effective two-body interaction experienced by a pair of solvated colloids. This low concentration limit of the depletion force has therefore received considerable attention. One route, which can be rigorously based on statistical mechanical sum rules, leads to an analytic result for the depletion force when evaluated by a key theoretical tool of colloidal science known as the Derjaguin approximation. A rival approach has been based on the assumption that modern density functional theories (DFT) can be trusted for systems of large size asymmetry. Unfortunately, these two theoretical predictions differ qualitatively for hard sphere models, as soon as the solvent density is higher than about 23 that at freezing. Recent theoretical attempts to understand this dramatic disagreement have led to the proposal that the Derjaguin and DFT routes represent opposite limiting behavior, for very large size asymmetry

  8. Operational Experience with Radioactive Source Calibration of the CMS Hadron Endcap Calorimeter Wedges with Phase I Upgrade Electronics

    CERN Document Server

    Bilki, Burak

    2017-01-01

    The Phase I Upgrade of the CMS Hadron Endcap Calorimeters consist of new photodetectors (Silicon Photomultipliers in place of Hybrid Photo-Diodes) and front-end electronics (QIE11). The upgrade will allow the elimination of the high amplitude noise and drifting response of the Hybrid Photo-Diodes, at the same time enabling the mitigation of the radiation damage of the scintillators and the wavelength shifting fibers with a larger spectral acceptance of the Silicon Photomultipliers. The upgrade will also allow to increase the longitudinal segmentation of the readout to be beneficial for pile-up mitigation and recalibration due to depth-dependent radiation damage.As a realistic operational exercise, the responses of the Hadron Endcap Calorimeter wedges are being calibrated with a $^{60}$Co radioactive source both with current and upgrade electronics. The exercise will provide a manifestation of the benefits of the upgrade. Here we describe the instrumentation details and the operational experiences related to t...

  9. Operational Experience with Radioactive Source Calibration of the CMS Hadron Endcap Calorimeter Wedges with Phase I Upgrade Electronics

    CERN Document Server

    Bilki, Burak

    2017-01-01

    The Phase I Upgrade of the CMS Hadron Endcap Calorimeters consists of new photodetectors and front-end electronics. The upgrade will allow the elimination of the high amplitude noise and drifting response of the Hybrid Photo-Diodes, at the same time enabling the mitigation of the radiation damage of the scintillators and the wavelength shifting fibers with a larger spectral acceptance of the Silicon Photomultipliers. The upgrade will also allow increasing the longitudinal segmentation of the readout to be beneficial for pile-up mitigation and recalibration due to depth-dependent radiation damage. As a realistic operational exercise, the responses of the Hadron Endcap Calorimeter wedges were calibrated with a 60Co radioactive source both with current and upgrade electronics. The exercise provided significant experience towards the full upgrade during the Year End Technical Stop 2017-2018. Here we describe the instrumentation details and the operational experiences related to the sourcing exercise.

  10. Evaluation of Wedged Arterial Injection as a New Technique for Delivery of Experimental Therapeutic Sustances into the Porcine Pancreas

    Directory of Open Access Journals (Sweden)

    Rafael Latorre

    2011-01-01

    Materials and Methods. Selective angiographies were completed in ten pigs under general anaesthesia. By superselective angiography, the catheter was inserted and wedged into the major pancreatic artery, blocking the blood flow. In order to evaluate the efficacy of the WAI method, a DNA-specific fluorescent dye (Hoechst 33258 was used. Results. Histological study revealed a uniform distribution of the fluorescent dye within the nuclei of the endocrine and exocrine pancreatic cells. Pancreatic and liver enzymes as well as histopathology of the pancreas were normal. Conclusion. WAI is a highly effective minimally invasive methodology to target the porcine pancreas. The findings suggest that WAI may contribute to developing preclinical assays of pancreas gene or cell-transfer therapies in swine model.

  11. Relaxation of the MCL after an Open-Wedge High Tibial Osteotomy results in decreasing contact pressures of the knee over time

    NARCIS (Netherlands)

    van Egmond, N.; Hannink, G.; Janssen, D.; Vrancken, A.C.; Verdonschot, N.; van Kampen, A.

    2017-01-01

    Purpose: The objective of this study was to investigate the effect of a medial open-wedge osteotomy (OWO) and the release of the superficial medial collateral ligament (MCL) on the tibiofemoral cartilage pressure, the MCL tension and the valgus laxity of the knee. Methods: Seven fresh-frozen, human

  12. Relaxation of the MCL after an Open-Wedge High Tibial Osteotomy results in decreasing contact pressures of the knee over time

    NARCIS (Netherlands)

    Egmond, N. van; Hannink, G.J.; Janssen, D.W.; Vrancken, A.C.; Verdonschot, N.J.; Kampen, A. van

    2017-01-01

    PURPOSE: The objective of this study was to investigate the effect of a medial open-wedge osteotomy (OWO) and the release of the superficial medial collateral ligament (MCL) on the tibiofemoral cartilage pressure, the MCL tension and the valgus laxity of the knee. METHODS: Seven fresh-frozen, human

  13. Nannofossil age constraints for the northern KwaZulu-Natal shelf-edge wedge: Implications for continental margin dynamics, South Africa, SW Indian Ocean

    Science.gov (United States)

    Green, A. N.; Ovechkina, M.; Uken, R.

    2008-10-01

    Samples collected from the shelf-edge wedge using surface grab samples and the Jago submersible constrain the KwaZulu-Natal shelf-edge wedge to a late Pliocene age on the basis of the absence of Gephyrocapsa oceanica s.l. and Discoaster brouweri, and the presence of Calcidiscus macintyrei. This correlates with proposed Tertiary sea-level curves for southern Africa and indicates relative sea-level fall during the late Pliocene coupled with hinterland uplift. Exposed failure scarps in the upper portions of submarine canyons yield sediment samples of early Pleistocene ages, indicating the uppermost age of deposition of clinoform topsets exposed in the scarp walls. Partially consolidated, interbedded silty and sandy deposits of similar age outcrop in the thalweg of Leven canyon at a depth of 150 m. These sediments provide an upper age limit of the shelf-edge wedge of early Pleistocene, giving a sedimentation rate of this wedge of 162-309 m/Ma. The distribution of widespread basal-most Pleistocene sediments on the upper slope indicates that these sediments escaped major reworking during sea-level falls associated with Pleistocene glaciations and remain as relict upper slope veneers. The absence of more recent sediments suggests that this area has been a zone of sediment bypass or starvation since the early Pleistocene. Areas where younger sediments mantle deposits of early Pleistocene ages represent areas of offshore bedload parting, re-distributing younger Holocene sediment offshore and downslope.

  14. A structural multidisciplinary approach to depression management in nursing-home residents: a multicentre, stepped-wedge cluster-randomised trial

    NARCIS (Netherlands)

    Leontjevas, R.; Gerritsen, D.L.; Smalbrugge, M.; Teerenstra, S.; Vernooij-Dassen, M.J.F.J.; Koopmans, R.T.C.M.

    2013-01-01

    BACKGROUND: Depression in nursing-home residents is often under-recognised. We aimed to establish the effectiveness of a structural approach to its management. METHODS: Between May 15, 2009, and April 30, 2011, we undertook a multicentre, stepped-wedge cluster-randomised trial in four provinces of

  15. HELP! Problems in executing a pragmatic, randomized, stepped wedge trial on the Hospital Elder Life Program to prevent delirium in older patients

    NARCIS (Netherlands)

    Heim, Noor; van Stel, Henk F.; Ettema, Roelof G A; van der Mast, Roos C; Inouye, Sharon K.; Schuurmans, Marieke J.

    2017-01-01

    BACKGROUND: A pragmatic, stepped wedge trial design can be an appealing design to evaluate complex interventions in real-life settings. However, there are certain pitfalls that need to be considered. This paper reports on the experiences and lessons learned from the conduct of a cluster randomized,

  16. Deep long-period earthquakes west of the volcanic arc in Oregon: evidence of serpentine dehydration in the fore-arc mantle wedge

    Science.gov (United States)

    Vidale, John E.; Schmidt, David A.; Malone, Stephen D.; Hotovec-Ellis, Alicia J.; Moran, Seth C.; Creager, Kenneth C.; Houston, Heidi

    2014-01-01

    Here we report on deep long-period earthquakes (DLPs) newly observed in four places in western Oregon. The DLPs are noteworthy for their location within the subduction fore arc: 40–80 km west of the volcanic arc, well above the slab, and near the Moho. These “offset DLPs” occur near the top of the inferred stagnant mantle wedge, which is likely to be serpentinized and cold. The lack of fore-arc DLPs elsewhere along the arc suggests that localized heating may be dehydrating the serpentinized mantle wedge at these latitudes and causing DLPs by dehydration embrittlement. Higher heat flow in this region could be introduced by anomalously hot mantle, associated with the western migration of volcanism across the High Lava Plains of eastern Oregon, entrained in the corner flow proximal to the mantle wedge. Alternatively, fluids rising from the subducting slab through the mantle wedge may be the source of offset DLPs. As far as we know, these are among the first DLPs to be observed in the fore arc of a subduction-zone system.

  17. Periodic verification of beam with wedge dynamics through analysis of dynalog files; Verificacion periodica de hace con cuna dinamica mediante analisis de los archivos dynalog

    Energy Technology Data Exchange (ETDEWEB)

    Camacho, C.; Perez-Alija, J.; Pedro, A.

    2013-07-01

    During the administration of the field such information is it sampled and collected in files called Dynalog. The objective of this work is the analysis of these files as a complement to regular quality control of the EDW technique, as well as the independent verification system of generation and control of dynamic wedge fields. (Author)

  18. PREPARATION OF LAYERED DOUBLE HYDROXIDES

    National Research Council Canada - National Science Library

    OGAWA, MAKOTO; INOMATA, KAZUYA

    2011-01-01

    Layered double hydroxides (LDHs) are class of materials with useful properties associated with their anion exchange abilities for a wide range of applications including bio and environmental problems...

  19. Colored Flag by Double Refraction.

    Science.gov (United States)

    Reid, Bill

    1994-01-01

    Describes various demonstrations that illustrate double refraction and rotation of the plane of polarization in stressed, transparent plastics, with the consequent production of colored designs. (ZWH)

  20. Along-strike variations in the Himalayan orogenic wedge structure in Bhutan from ambient seismic noise tomography

    Science.gov (United States)

    Singer, Julia; Obermann, Anne; Kissling, Eduard; Fang, Hongjian; Hetényi, György; Grujic, Djordje

    2017-04-01

    The geological units and tectonic structure exposed in the Bhutan Himalaya document significant regional variations, expressed primarily as tectonic windows and klippen. The along-strike variations of these structures and their metamorphic grade are usually associated with the formation of local duplexes in the underlying tectonic units. To investigate these variations and their extent in depth, we image the isotropic shear-wave velocity structure of the orogenic wedge by ambient noise tomography. Group velocities are extracted from cross correlations of ambient seismic noise, recorded by the temporary GANSSER network in Bhutan. The upper crustal structure beneath Bhutan is mapped down to 18 km depth by directly inverting Rayleigh-wave group velocity measurements in the period range between 2 and 20 s with a ray tracing based inversion approach. Our results reveal several distinct high shear-wave velocity anomalies (≥3.6 km/s) and reflect the along-strike variations in the upper crustal structure in relation to the alternating tectonic windows and klippen at the surface. In correlation with the surface geology in the northern part of Bhutan, we interpret shallow high shear-wave velocity anomalies as quarzite-dominated rocks or felsic migmatites with large intrusions of leucogranites. High-velocity anomalies in the orogenic wedge in eastern and western Bhutan correlate with the local geometry of the Main Himalayan Thrust and provide evidence for the formation and depth extent of localized duplexes of quartzite dominated lithology in association with the formation of tectonic windows in the Bhutan Himalaya.

  1. Geophysical evidence for wedging in the San Gorgonio Pass structural knot, southern San Andreas fault zone, southern California

    Science.gov (United States)

    Langenheim, V.E.; Jachens, R.C.; Matti, J.C.; Hauksson, E.; Morton, D.M.; Christensen, A.

    2005-01-01

    Geophysical data and surface geology define intertonguing thrust wedges that form the upper crust in the San Gorgonio Pass region. This picture serves as the basis for inferring past fault movements within the San Andreas system, which are fundamental to understanding the tectonic evolution of the San Gorgonio Pass region. Interpretation of gravity data indicates that sedimentary rocks have been thrust at least 5 km in the central part of San Gorgonio Pass beneath basement rocks of the southeast San Bernardino Mountains. Subtle, long-wavelength magnetic anomalies indicate that a magnetic body extends in the subsurface north of San Gorgonio Pass and south under Peninsular Ranges basement, and has a southern edge that is roughly parallel to, but 5-6 km south of, the surface trace of the Banning fault. This deep magnetic body is composed either of upper-plate rocks of San Gabriel Mountains basement or rocks of San Bernardino Mountains basement or both. We suggest that transpression across the San Gorgonio Pass region drove a wedge of Peninsular Ranges basement and its overlying sedimentary cover northward into the San Bernardino Mountains during the Neogene, offsetting the Banning fault at shallow depth. Average rates of convergence implied by this offset are broadly consistent with estimates of convergence from other geologic and geodetic data. Seismicity suggests a deeper detachment surface beneath the deep magnetic body. This interpretation suggests that the fault mapped at the surface evolved not only in map but also in cross-sectional view. Given the multilayered nature of deformation, it is unlikely that the San Andreas fault will rupture cleanly through the complex structures in San Gorgonio Pass. ?? 2005 Geological Society of America.

  2. First Metatarsophalangeal Contact Properties Following Proximal Opening Wedge and Scarf Osteotomies for Hallux Valgus Correction: A Biomechanical Study.

    Science.gov (United States)

    Kia, Cameron; Yoshida, Ryu; Cote, Mark; DiVenere, Jessica; Geaney, Lauren E

    2017-04-01

    Proximal opening wedge osteotomy (POWO) is an established procedure for moderate to severe hallux valgus. A common concern of this procedure is that it results in lengthening of the first metatarsal, which could cause increased intra-articular pressure of the first metatarsophalangeal joint (MTP) and may ultimately lead to arthritis because of these altered mechanics. The purpose of this study was to use a cadaveric model to compare intra-articular pressures and articulating contact properties of the MTP joint following either scarf osteotomy or POWO. Fresh-frozen cadaveric below-knee specimens with pre-existing hallux valgus (n = 12) and specimens without hallux valgus (n = 6, control group) were used. The hallux valgus specimens were stratified into 2 groups (n = 6 each): POWO or scarf osteotomy. The groups were matched based on the degree of deformity. Peak intra-articular pressure, force, and area were measured in all normal, preoperative, and postoperative specimens with a simulated weightbearing model. These measurements were made with a pressure transducer placed within the first MTP joint. Postoperatively POWO group had slightly higher contact forces and pressures compared to the scarf group and lower contact forces and pressures than those of the normal group but were not statistically significant ( P > .05). Normal specimens had higher intra-articular force, pressure, and area than postoperative specimens but the difference was not found to be significant. First metatarsal lengthening was found in both the scarf and POWO specimens; however, neither increase was found to be significant ( P > .05). The results from this study show that after operative correction, contact properties of the fist MTP joint among normal, POWO, and scarf osteotomy groups revealed no significant differences. First MTP joints in those with hallux valgus had significantly lower contact force and pressure compared to those without hallux valgus. With little long-term outcomes of

  3. A 2D ion chamber array audit of wedged and asymmetric fields in an inhomogeneous lung phantom

    Energy Technology Data Exchange (ETDEWEB)

    Lye, Jessica; Dunn, Leon, E-mail: leon.dunn@arpansa.gov.au; Alves, Andrew [Australian Clinical Dosimetry Service, Yallambie, Victoria 3085 (Australia); Kenny, John [Australian Clinical Dosimetry Service, Yallambie, Victoria 3085, Australia and Radiation Oncology Queensland, Toowoomba, Queensland 4350 (Australia); Lehmann, Joerg; Williams, Ivan [Australian Clinical Dosimetry Service, Yallambie, Victoria 3085, Australia and School of Applied Science, RMIT University, Melbourne 3000 (Australia); Kron, Tomas [School of Applied Science, RMIT University, Melbourne 3000, Australia and Peter MacCallum Cancer Centre, Melbourne 3008 (Australia); Cole, Andrew [Australian Clinical Dosimetry Service, Yallambie, Victoria 3085, Australia and Australian Radiation Protection and Nuclear Safety Agency, Yallambie, Victoria 3085 (Australia)

    2014-10-15

    Purpose: The Australian Clinical Dosimetry Service (ACDS) has implemented a new method of a nonreference condition Level II type dosimetric audit of radiotherapy services to increase measurement accuracy and patient safety within Australia. The aim of this work is to describe the methodology, tolerances, and outcomes from the new audit. Methods: The ACDS Level II audit measures the dose delivered in 2D planes using an ionization chamber based array positioned at multiple depths. Measurements are made in rectilinear homogeneous and inhomogeneous phantoms composed of slabs of solid water and lung. Computer generated computed tomography data sets of the rectilinear phantoms are supplied to the facility prior to audit for planning of a range of cases including reference fields, asymmetric fields, and wedged fields. The audit assesses 3D planning with 6 MV photons with a static (zero degree) gantry. Scoring is performed using local dose differences between the planned and measured dose within 80% of the field width. The overall audit result is determined by the maximum dose difference over all scoring points, cases, and planes. Pass (Optimal Level) is defined as maximum dose difference ≤3.3%, Pass (Action Level) is ≤5.0%, and Fail (Out of Tolerance) is >5.0%. Results: At close of 2013, the ACDS had performed 24 Level II audits. 63% of the audits passed, 33% failed, and the remaining audit was not assessable. Of the 15 audits that passed, 3 were at Pass (Action Level). The high fail rate is largely due to a systemic issue with modeling asymmetric 60° wedges which caused a delivered overdose of 5%–8%. Conclusions: The ACDS has implemented a nonreference condition Level II type audit, based on ion chamber 2D array measurements in an inhomogeneous slab phantom. The powerful diagnostic ability of this audit has allowed the ACDS to rigorously test the treatment planning systems implemented in Australian radiotherapy facilities. Recommendations from audits have led to

  4. Analysis of the behavior of reinforced concrete columns strengthened with sleeve wedge bolts and a self compacting concrete layer

    Directory of Open Access Journals (Sweden)

    M. G. Marques

    Full Text Available Strengthening of reinforced concrete columns by jacketing is one of the most common structural rehabilitation techniques in Brazil. For adequate performance, it is necessary, among others, to avoid detachment of the new concrete layer (strengthening material from the old concrete substrate when the strengthened member is again in service conditions. This paper describes the test results of eight reinforced concrete rectangular columns subjected to combined compression and one-axis bending to evaluate the efficiency of using sleeve wedge bolts across the new concrete/old concrete interface to avoid detachment. The strengthening technique, in this case, consists of adding a layer of self-compacting concrete to one face of the column. Two columns tested were monolithic and named PO (original column e PR (reference column. The other six columns were strengthened using a new 35 mm thick self-compacting concrete layer attached to the column face subjected to highest compressive stresses. Column PO had a 120mm by 250 mm rectangular cross section and its results gave information about column behavior without the use of strengthening. Column PR had a 155mm by 250 mm rectangular cross section and its cross section dimensions matched the strengthened columns but it was cast monolithically. To improve bond conditions between the existing concrete and the new concrete, the concrete surface was roughened and the outermost aggregate was exposed using hydro jetting. Holes along the concrete surface were made to insert the wedge bolts responsible for increasing the bond between the two concrete surfaces. The difference among the six strengthened columns was the position and amount of bolts used. Results indicate that the position and amount of the bolts alters significantly the strength capacity of the columns, since premature rupture by concrete detachment was delayed.

  5. Clinical and radiological outcome after mini-open Latarjet technique with fixation of coracoid with Arthrex wedge mini-plate.

    Science.gov (United States)

    Chaudhary, Deepak; Goyal, Ankit; Joshi, Deepak; Jain, Vineet; Mohindra, Mukul; Mehta, Nitin

    2016-01-01

    Technical faults leading to coracoid fractures during screw insertion and coracoid graft osteolysis are concerns with standard screw fixation techniques in Latarjet procedure. The purpose of this study is to share our experience using Arthrex wedge profile plate with mini-open technique for graft fixation, that ensures better load distribution between coracoid graft and glenoid. We did retrospective analysis of 24 patients with recurrent anterior shoulder instability after failed arthroscopic Bankart's repair. Arthroscopic examination of affected shoulder was done in lateral position before making patient supine for open Latarjet. A low profile wedge plate (Arthrex) with two screws was used for the procedure. CT analysis was performed post-operatively at 6 months to see graft union and results were evaluated using the Rowe and Walch Duplay score. Mean follow-up time was 26 months. Postoperatively, mean forward elevation was 170.6 + 4.6° (loss of average 5.9°) and mean external rotation was 42.5 + 5.3° (loss of average 3.1°). All patients returned to their previous occupation. None reported to be having any recurrent subluxation. Functional assessment done using Rowe score and Walch Duplay score showed statistically significant improvement (p value 0.034). There were no implant-related complications and no case of coracoid graft osteolysis. Mini-open Latarjet with graft fixation with Arthrex mini-plate provides satisfactory outcome in patients who require reoperation due to dramatic bone loss and failed soft tissue reconstruction. The modified incision improves exposure enabling plate fixation and the secure fixation accelerates rehabilitation.

  6. Crowdsourcing to promote HIV testing among MSM in China: study protocol for a stepped wedge randomized controlled trial.

    Science.gov (United States)

    Tucker, Joseph D

    2017-10-02

    HIV testing for marginalized populations is critical to controlling the HIV epidemic. However, the HIV testing rate among men who have sex with men (MSM) in China remains low. Crowdsourcing, the process of shifting individual tasks to a group, has been increasingly adopted in public health programs and may be a useful tool for spurring innovation in HIV testing campaigns. We designed a multi-site study to develop a crowdsourced HIV test promotion campaign and evaluate its effectiveness against conventional campaigns among MSM in China. This study will use an adaptation of the stepped wedge, randomized controlled trial design. A total of eight major metropolitan cities in China will be randomized to sequentially initiate interventions at 3-month intervals. The intervention uses crowdsourcing at multiple steps to sustain crowd contribution. Approximately 1280 MSM, who are 16 years of age or over, live in the intervention city, have not been tested for HIV in the past 3 months, and are not living with HIV, will be recruited. Recruitment will take place through banner advertisements on a large gay dating app along with other social media platforms. Participants will complete one follow-up survey every 3 months for 12 months to evaluate their HIV testing uptake in the past 3 months and secondary outcomes including syphilis testing, sex without condoms, community engagement, testing stigma, and other related outcomes. MSM HIV testing rates remain poor in China. Innovative methods to promote HIV testing are urgently needed. With a large-scale, stepped wedge, randomized controlled trial our study can improve understanding of crowdsourcing's long-term effectiveness in public health campaigns, expand HIV testing coverage among a key population, and inform intervention design in related public health fields. ClinicalTrials.gov, NCT02796963 . Registered on 23 May 2016.

  7. First Metatarsal Proximal Opening Wedge Osteotomy for Correction of Hallux Valgus Deformity: Comparison of Straight versus Oblique Osteotomy

    Science.gov (United States)

    Han, Seung Hwan; Park, Eui Hyun; Jo, Joon; Koh, Yong Gon; Lee, Jin Woo; Choi, Woo Jin

    2015-01-01

    Purpose The aim of this study was to compare clinical and radiographic outcomes of proximal opening wedge osteotomy using a straight versus oblique osteotomy. Materials and Methods We retrospectively reviewed 104 consecutive first metatarsal proximal opening wedge osteotomies performed in 95 patients with hallux valgus deformity. Twenty-six feet were treated using straight metatarsal osteotomy (group A), whereas 78 feet were treated using oblique metatarsal osteotomy (group B). The hallux valgus angle (HVA), intermetatarsal angle (IMA), distal metatarsal articular angle, and distance from the first to the second metatarsal (distance) were measured for radiographic evaluation, whereas the American Orthopaedic Foot and Ankle Society (AOFAS) forefoot score was used for clinical evaluation. Results Significant corrections in the HVA, IMA, and distance from the first to the second metatarsal were obtained in both groups at the last follow-up (p<0.001). There was no difference in the mean IMA correction between the 2 groups (6.1±2.7° in group A and 6.0±2.1° in group B). However, a greater correction in the HVA and distance from the first to the second metatarsal were found in group B (HVA, 13.2±8.2°; distance, 25.1±0.2 mm) compared to group A (HVA, 20.9±7.7°; distance, 28.1±0.3 mm; p<0.001). AOFAS scores were improved in both groups. However, group B demonstrated a greater improvement relative to group A (p=0.005). Conclusion Compared with a straight first metatarsal osteotomy, an oblique first metatarsal osteotomy yielded better clinical and radiological outcomes. PMID:25837181

  8. Double-Skin Facade

    DEFF Research Database (Denmark)

    Kalyanova, Olena

    Double-Skin Facades (DSF) are gaining popularity that, in fact, appears to be independent from sturdy critics of the concept in the past years. DSF buildings are being built in Europe and worldwide, DSF concept is being taught at schools of architecture and fully glazed office buildings are being...... favored by companies and their employees. To bring the reduction of energy use in these buildings application of suitable tools and methods is necessary to achieve successful design solutions. Earlier work on the topic of DSF modelling was examined from various publications. As a result, the main...... difficulties experienced by scientists when attempting to model DSF thermal and energy performance were examined. In addition, the lack of experimental studies and empirical validation of models was realized, many numerical models have not been empirically validated and most of them require an expert knowledge...

  9. Layered double hydroxides

    DEFF Research Database (Denmark)

    López Rayo, Sandra; Imran, Ahmad; Hansen, Hans Chr. Bruun

    2017-01-01

    A novel zinc (Zn) fertilizer concept based on Zn doped layered double hydroxides (Zn-doped Mg-Fe-LDHs) has been investigated. Zn-doped Mg-Fe-LDHs were synthetized, their chemical composition was analyzed and their nutrient release was studied in buffered solutions with different pH values. Uptake...... of Zn by barley (Hordeum vulgare cv. Antonia) was evaluated in short- (8 weeks), medium- (11 weeks) and long-term (28 weeks) experiments in quartz sand and in a calcareous soil enriched with Zn-doped Mg-Fe-LDHs. The Zn release rate of the Zn-doped Mg-Fe-LDHs was described by a first-order kinetics...

  10. Dual double field theory

    Energy Technology Data Exchange (ETDEWEB)

    Bergshoeff, Eric A. [Centre for Theoretical Physics, University of Groningen,Nijenborgh 4, 9747 AG Groningen (Netherlands); Hohm, Olaf [Simons Center for Geometry and Physics, Stony Brook University,Stony Brook, NY 11794-3636 (United States); Penas, Victor A. [Centre for Theoretical Physics, University of Groningen,Nijenborgh 4, 9747 AG Groningen (Netherlands); Riccioni, Fabio [INFN - Sezione di Roma, Dipartimento di Fisica, Università di Roma “La Sapienza”,Piazzale Aldo Moro 2, 00185 Roma (Italy)

    2016-06-06

    We present the dual formulation of double field theory at the linearized level. This is a classically equivalent theory describing the duals of the dilaton, the Kalb-Ramond field and the graviton in a T-duality or O(D,D) covariant way. In agreement with previous proposals, the resulting theory encodes fields in mixed Young-tableau representations, combining them into an antisymmetric 4-tensor under O(D,D). In contrast to previous proposals, the theory also requires an antisymmetric 2-tensor and a singlet, which are not all pure gauge. The need for these additional fields is analogous to a similar phenomenon for “exotic' dualizations, and we clarify this by comparing with the dualizations of the component fields. We close with some speculative remarks on the significance of these observations for the full non-linear theory yet to be constructed.

  11. Coupled Double Quantum Wells

    Directory of Open Access Journals (Sweden)

    Élder Mantovani Lopes

    2010-12-01

    Full Text Available The progress of the semiconductor growth techniques allows the opportunity to produce new semiconductors devices that may contribute to the development of the nanotechnology. The fabrication of semiconductor heterostructures with high quality allows the obtaining of new effects based on the quantum properties of those systems, which have stimulated great technological interest, especially on the optoelectronic and telecommunications fields. In this work some basic concepts related to one of those heterostructures are discussed: the Coupled Double Quantum Well (CDQW. The deduction of the expression for the determination of the energy levels in CDQWs is presented in details. The results obtained through this expression are compared with experimental results obtained through photoluminescence (PL measurements, complementing the work.

  12. A non-deltaic clinoform wedge fed by multiple sources off São Sebastião Island, southeastern Brazilian Shelf

    Science.gov (United States)

    Vieira, Ivo; Lobo, Francisco José; Montoya-Montes, Isabel; Siegle, Eduardo; Passos, Jorge Luiz; De Mahiques, Michel Michaelovitch

    2018-02-01

    São Sebastião Island (SSI) marks the latitudinal boundary between two sedimentological and geochemical provinces in the São Paulo Bight, an arc-shaped sector of the southeastern Brazilian Shelf. The island is separated from the continent by the narrow, deep São Sebastião Channel (SSC). A relatively thick sediment wedge—the São Sebastião Wedge (SSW)—has been formed offshore SSI. This study explores the possible genetic and evolutionary mechanisms of the wedge, bearing in mind that clinoform wedges can form at considerable distances from major fluvial sources. For that, a marine geological database has been interpreted comprising high-resolution seismic data, a surficial sediment map and several sediment cores, from which radiocarbon dates were obtained and sedimentation rates deduced. A wave model was also applied to obtain the dominant wave directions. The SSW is a wedge-shaped deposit, and its internal structure presents three seismic units. The two lowest are wedge shaped and arranged in a backstepping pattern. The most recent unit is mostly aggradational and can be divided into three seismic subunits. Sedimentological data show that at least the most recent unit is composed of a mixture of sands and silts. Modeled wave conditions indicate a major influence from southerly waves that are able to remobilize shelf sediments and to create a bypass sediment zone until the foreset of the deposit is reached at the water depths where the SSW is found. Taken together, these data suggest that the SSW formed through contributions from different sediment sources, and should be regarded as an intermediate case of a non-deltaic clinoform wedge. Sand transport in the area involves wind-driven currents passing through the SSC and sediment remobilization by energetic southerly waves. Fine-grained sediment is derived mostly from the joint contributions of many minor catchments located north of the island, and this sediment is later transported southwestward by the

  13. Draping Double-Layer Woven Fabrics Onto Double-Curvature ...

    African Journals Online (AJOL)

    Draping woven fabrics to complex parts with double curvature leads to complex redistribution and reorientation of the yarns in composites reinforced with woven preforms. To reduce the risk of fabric tearing or wrinkling we propose to use double-layer woven fabrics. This paper presents a simulation model for draping

  14. Discriminating Sediment Supply versus Accommodation Controls on Foreland Basin Stratigraphic Architecture in the Book Cliffs, central Utah using Detrital Double Dating

    Science.gov (United States)

    Bartschi, N.; Saylor, J. E.; Blum, M. D.

    2014-12-01

    Middle-late Campanian strata of the Book Cliffs record the deposition of three clastic wedges in the foreland basin east of the Sevier fold-thrust belt. Variations in wedge geometries provide an opportunity to evaluate the effects of sediment supply versus accommodation on foreland basin architecture. There is an increase in eastward progradation rate between the L. and M. Castlegate Sandstone, followed by a return to slower progradation rates in the overlying Bluecastle Tongue, and Price River Formation, as well as their lateral equivalents. Rapid progradation may be caused by increased sediment supply, due either to rapid exhumation in the Sevier fold-thrust belt, or changes in the sediment source. Alternatively, reduced accommodation within the foreland basin due to uplift during initial Laramide deformation could produce the same rapid progradation. In this scenario, decreased progradation would be coincident with enhanced foreland basin subsidence and rapid sediment accumulation in the proximal foredeep. We test these hypotheses using thermo- and geochronology to double date individual detrital grains, enabling identification of changes in lag time and sediment provenance. Upsection decreases or increases in lag time correspond to increased or decreased exhumation rates, respectively, or introduction of a new upper crustal sedimentary source. We focus on 21 samples from 7 measured sections along depositional strike and dip. Samples were collected from the upper Blackhawk Formation, L. and M. Castlegate Sandstone, Bluecastle Tongue, Price River Formation, and their lateral equivalents. Initial results indicate major sediment provenance changes associated with the transition between slow and rapid wedge progradation, as well as minor provenance changes within individual wedges. There is also a significantly greater proportion of Cordilleran magmatic arc grains in distal locations than in proximal locations, interpreted as sediment mixing during transport.

  15. Two-dimensional Numerical Models of Accretionary Wedges Deformation in Response to Subduction and Obduction: Evidence from the Middle Part of the Manila Trench

    Science.gov (United States)

    Ma, L.; Ding, W.; Chen, L.; Gerya, T.

    2016-12-01

    The Manila Trench is located at the eastern boundary of the South China Sea (SCS). It was created by the subduction of the South China Sea Plate beneath the Philippine Sea Plate since the early Neogene, and also influenced by the northwestern movement of the Philippine Sea Plate. There is wide discussion whether the dual-subduction and widespread seamounts in the South China Sea would have play important roles in the 'S-shaped' geometry and the different diving angle along the Manila Trench. Multi-beam tectono-geomorphological studies on the accretionary wedges have suggested that: (1) the stress direction of the subduction along the middle part of the Manila Trench, between 17o and 18 o N, is NW55 o; (2) The Manila Trench is actually caused by obduction due to the northwestern movement of the Philippine Sea Plate. Although the NW 55 o stress direction has been supported by detailed analysis on the trend of the folds, thrust faults, extension fractures and large sea-floor canyon, its obduction-origin is purely based on regional structure. Here we use 2D numerical modeling experiments to investigate the deformation style of accretionary wedge in response to the seamounts subduction and obduction, and provide new insights into the mechanism responsible for the Luzon obduction along the Manila Trench. Our preliminary results show that: (1) the accretionary wedge is eroded faster in subduction model; (2) the velocity field direction of the slab differs in two models at the beginning of seamount subduction, which is vertical in obduction model, but oblique in subduction model; (3) both sides of the accretionary wedge deform strongly in subduction model, whereas in obduction model only the leading edge shows intensive deformation. Further modelling will focus on other parts of the Manila Trench with different slab age and subduction velocity to see their tectonic influences on the accretionary wedges.

  16. Orbits of four double stars

    Directory of Open Access Journals (Sweden)

    Novaković B.

    2006-01-01

    Full Text Available We present orbits of four double stars. Orbits of stars WDS 23516+4205 = ADS 17050 and WDS 18239+5848 = ADS 11336 were calculated for the first time. Orbits of double stars WDS 02022+3643 = ADS 1613 and WDS 18443+3940 = ADS 11635 were revised. We have also determined their masses, dynamical parallaxes and ephemerides.

  17. Empirically Unbinding the Double Bind.

    Science.gov (United States)

    Olson, David H.

    The theoretical concept of the double bind and the possibilities for researching it are discussed. The author has observed that theory and research, which should be reciprocal and mutually beneficial, have been working, as concerns the double bind, at odds with one another. Two approaches to empirically investigating the concept are considered via…

  18. Hedging Double Barriers with Singles

    NARCIS (Netherlands)

    Sbuelz, A.

    2000-01-01

    Double barrier options provide risk managers with good-deal flexibility in tailoring portfolio returns.Their hedges offer full protection only if unwound along the barriers.This work provides non-dynamic hedges that project the risk of double barriers on to single barriers.Non-dynamic hedges

  19. Double layer relaxation in colloids

    NARCIS (Netherlands)

    Kijlstra, J.

    1992-01-01

    The purpose of the present study is to improve our insight into the relaxation of the electrical double layer around particles in hydrophobic sols. A detailed knowledge of the relaxation mechanisms is required to explain the behaviour of sols under conditions where the double layer is

  20. Double parton scattering theory overview

    NARCIS (Netherlands)

    Diehl, Markus; Gaunt, Jonathan R.

    2017-01-01

    The dynamics of double hard scattering in proton-proton collisions is quite involved compared with the familiar case of single hard scattering. In this contribution, we review our theoretical understanding of double hard scattering and of its interplay with other reaction mechanisms.

  1. Natural double inflation

    Science.gov (United States)

    Occhionero, F.; Litterio, M.; Capozziello, S.; Amendola, L.

    The astronomical interest of double inflation stems from the possibility it gives of inserting a feature in an otherwise featureless (or scale invariant) perturbation spectrum, precisely at the scale (100 Mpc, say) that goes through the horizon at the (sharp) separations between the two successive inflations. Double inflation occurs when two scalar fields (or inflatons) dominate sequentially the cosmic expansion or when vacuum polarization — Ricci scalar R squared added to the Lagrangian — is taken into account and only one inflaton ψ is present. (This perhaps is more natural as it exploits quantum effects to reduce to one the number of the ad hoc ingredients.) In that case we know from Starobinsky's pioneering work that the first inflation is driven by R — rightly called then scalaron — under the rules of Fourth Order Gravity, (FOG), while the second is driven by ψ under the rules of ordinary General Relativity, (GR). Unfortunately most of the appeal of the scalaron-inflaton scenario in relation to the feature in the perturbation spectrum, is lost because a delicate fine tuning of the value of the (second) inflaton at the beginning of the second inflation is required, in the absence of which the two inflations merge in one and no scale is singled out. In order to overcome this difficulty, we introduce in the Lagrangian density a new scalar coupling between ψ and R2, analogous to the well known non minimal coupling between ψ and R of canonical GR. We show that in this way the two inflationary episodes of FOG and GR may be neatly distinguished from each other, regardless of the initial value of ψ. This is due to the influence of the coupling on the shape of the conformal potential, in which one can easily carve a channel of evolution, consisting in fact of two orthogonal valleys. Then, for most of phase space the attractor is this doubly inflationary trajectory that lies at the bottom of the two valleys (Fig. 1). In fact, in this case the Universe first

  2. A Handbook of Double Stars

    Science.gov (United States)

    Crossley, Edward; Gledhill, Joseph; Wilson, James M.

    2011-11-01

    Preface; Part I. Historical, and Descriptive of Instruments and Methods: 1. Historical introduction; 2. The Equatorial: its construction and adjustments; 3. Some account of the Equatorials which have been used by double-star observers; 4. The micrometer; 5. Methods of observing double stars; Part II. On the Calculation of the Orbit of a Binary Star: 1. Introduction; 2. Example of an orbit worked by a graphical method; 3. Dr. Doberck's example of an orbit worked by analytical methods; 4. On relative rectilinear motion; 5. On the effect of proper motion and parallax on the observed position angles and distance of an optically double star; 6. On the errors of observation and the combination of observations; Part III. The Catalogue and Measures: Introductory remarks; A catalogue of binary and other double starts deserving of attention; Lists of measures, with historical notes, etc.; Supplementary list of measures; Appendix; Additional notes to measures; Binary stars classified; Note on systematic errors in the measures of angle and distance of double stars; Part IV. Bibliography: A. Some of the most important works and papers on double stars; B. Some papers on the micrometer; C. Some papers on the colours of double stars; Additional notes; Corrections 1880.

  3. Effect of Mantle Wedge Hybridization by Sediment Melt on Geochemistry of Arc Magma and Arc Mantle Source - Insights from Laboratory Experiments at High Pressures and Temperatures

    Science.gov (United States)

    Mallik, A.; Dasgupta, R.; Tsuno, K.; Nelson, J. M.

    2015-12-01

    Generation of arc magmas involves metasomatism of the mantle wedge by slab-derived H2O-rich fluids and/or melts and subsequent melting of the modified source. The chemistry of arc magmas and the residual mantle wedge are not only regulated by the chemistry of the slab input, but also by the phase relations of metasomatism or hybridization process in the wedge. The sediment-derived silica-rich fluids and hydrous partial melts create orthopyroxene-rich zones in the mantle wedge, due to reaction of mantle olivine with silica in the fluid/melt [1,2]. Geochemical evidence for such a reaction comes from pyroxenitic lithologies coexisting with peridotite in supra-subduction zones. In this study, we have simulated the partial melting of a parcel of mantle wedge modified by bulk addition of sediment-derived melt with variable H2O contents to investigate the major and trace element chemistry of the magmas and the residues formed by this process. Experiments at 2-3 GPa and 1150-1300 °C were conducted on mixtures of 25% sediment-derived melt and 75% lherzolite, with bulk H2O contents varying from 2 to 6 wt.%. Partial reactive crystallization of the rhyolitic slab-derived melt and partial melting of the mixed source produced a range of melt compositions from ultra-K basanites to basaltic andesites, in equilibrium with an orthopyroxene ± phlogopite ± clinopyroxene ± garnet bearing residue, depending on P and bulk H2O content. Model calculations using partition coefficients (from literature) of trace elements between experimental minerals and silicate melt suggest that the geochemical signatures of the slab-derived melt, such as low Ce/Pb and depletion in Nb and Ta (characteristic slab signatures) are not erased from the resulting melt owing to reactive crystallization. The residual mineral assemblage is also found to be similar to the supra-subduction zone lithologies, such as those found in Dabie Shan (China) and Sanbagawa Belt (Japan). In this presentation, we will also

  4. The Effect of Films on the Capillary Pressure - Saturation Hysteresis in a Smooth-walled Wedge Channel

    Science.gov (United States)

    Liu, Y.; Nolte, D.; Pyrak-Nolte, L. J.

    2010-12-01

    Thin fluid films are central to many multiphase flow applications; however, experimental investigation of films requires direct detection and measurement of films. Water film thicknesses can range from a few nanometers to several micrometers and may vary depending on local pore structures and material properties. In this study, laser confocal microscopy was employed to image volumetric fluid distribution and 3D interfaces during drainage and imbibition processes in a smooth-walled channel. Confocal microscopy provides an effective method to image directly 3D thin films and to measure film thickness, volume, and other parameters. The detection resolution is 1.19 μm/pixel through a 10x objective lens and is 0.72 μm/pixel through a 20x lens. A smooth-walled wedge channel was fabricated to study the generation and relaxation of water films in the non-wetting phase of air. The effect of films on contact angle, interfacial area per volume (IAV), and capillary pressure - saturation (Pc - Sw) hysteresis were also investigated. Micromodels were fabricated using a negative photoresist (SU-8) sandwiched between two cover glasses. An all-SU-8 smooth-walled wedge channel was fabricated by laser direct-writing two-photon polymerization, 100 μm wide at the outlet and 20 μm at the inlet with a constant aperture of 40 μm. A laser scanning confocal microscope was used to image the wetting (water) and non-wetting (air) phase distributions by labeling the wetting phase with a fluorophore, Alex Fluor-488, 1.0% by wieght. The 3D air-water interfaces were imaged and then reconstructed using a stack of confocal images. The samples were initially saturated with water, the wetting phase. A series of drainage and imbibition cycles were performed by incrementing or decrementing the air pressure. At each pressure, the system was allowed to equilibrate and then a stack of scans in depth was collected to acquire the 3D fluid distribution for the given pressure. The confocal images were

  5. Creative Double Bind in Oral Interpretation.

    Science.gov (United States)

    Peterson, Eric E.; Langellier, Kristin M.

    1982-01-01

    Explains how oral interpretation is uniquely communicative and how the double bind theory of communication can include creativity. Discusses (1) double bind and oral interpretation, (2) creating aesthetic text, and (3) the performance of double bind. (PD)

  6. Mixed methods evaluation of targeted case finding for cardiovascular disease prevention using a stepped wedged cluster RCT

    Directory of Open Access Journals (Sweden)

    Marshall Tom

    2012-10-01

    Full Text Available Abstract Background A pilot project cardiovascular prevention was implemented in Sandwell (West Midlands, UK. This used electronic primary care records to identify untreated patients at high risk of cardiovascular disease then invited these high risk patients for assessment by a nurse in their own general practice. Those found to be eligible for treatment were offered treatment. During the pilot a higher proportion of high risk patients were started on treatment in the intervention practices than in control practices. Following the apparent success of the prevention project, it was intended to extend the service to all practices across the Sandwell area. However the pilot project was not a robust evaluation. There was a need for an efficient evaluation that would not disrupt the planned rollout of the project. Methods/design Project nurses will sequentially implement targeted cardiovascular case finding in a phased way across all general practices, with the sequence of general practices determined randomly. This is a stepped wedge randomised controlled trial design. The target population is patients aged 35 to 74, without diabetes or cardiovascular disease whose ten-year cardiovascular risk, (determined from data in their electronic records is ≥20%. The primary outcome is the number of high risk patients started on treatment, because these data could be efficiently obtained from electronic primary care records. From this we can determine the effects of the case finding programme on the proportion of high risk patients started on treatment in practices before and after implementation of targeted case finding. Cost-effectiveness will be modelled from the predicted effects of treatments on cardiovascular events and associated health service costs. Alongside the implementation it is intended to interview clinical staff and patients who participated in the programme in order to determine acceptability to patients and clinicians. Practical

  7. Splay Faults and Associated Mass Transport Deposits in the Manila Accretionary Wedge near Taiwan: Implications for Geohazards

    Science.gov (United States)

    Lin, A. T.; Liu, C. S.; Dirgantara, F.

    2015-12-01

    Plate interface megathrusts are major seismogenic faults in subduction zone, capable of generating great earthquakes with widespread submarine landslides and damaging tsunami. Upward branching of megathrusts results in splay faults in the accretionary wedge. Reflection seismic data across the accretionary wedge off southern Taiwan, reveal at least two strands of splay faults as well as multiple stacked mass transport deposits (MTDs) nearby the faults. With the help of sediment coring and age datings in the vicinity of the splay fault, implications for temporal evolution of the mass wasting processes and episodic activities of splay faults are discussed in this paper. Seismic data show two branches of arcward and gently-dipping splay faults with two slope basins lying in the footwall and hangingwall of the faults, respectively. The older and buried splay fault is inactive as the fault tip is covered by up to 1000 m thick sediments in the footwall slope basin, indicating that it ceased to be active around 0.5 Ma ago. Repeated slip of this fault prior to ~0.5 Ma ago may also result in 4 stacked and multiple mass transport deposits (MTDs) of up to 700-m thick found in vicinity of this fault. This fossil splay fault is characterized by reflection polarity similar to that of seafloor, indicative of low water saturation along the fault zone and hence not an active fluid conduit. The younger and overlying splay fault cuts through the seafloor and the emergent fault tip lying at the toe of steep slope (~ 15 degree) with significant slope break. There is also a 500-m horizontal offset, between the buried paleo-seafloor in the footwall and the present-day seafloor on the hangingwall. The reflection polarity of this fault zone is reversed to that of seafloor, indicating fluid rich for this fault patch. These lines of evidence suggest that this young splay fault is an active fault with active fluid circulation along the fault. Our results indicate that the old splay fault

  8. [Finite element analysis on the effect of lateral wedge insole intervention on the contact characteristics of the subtalar joint].

    Science.gov (United States)

    Zhou, En-Chang; Tang, Ping; Zhu, Chuan-Ying; Liu, Shi-Ming

    2017-01-25

    To establish a three-dimensional finite element model of the lower limb bones, and investigate the changes of the contact characteristics of the subtalar joint after using laterally wedge insole intervention. Using the reverse modeling technology, the lower limb bones of normal adult volunteers was scanned by CT. Mimics 10.0 and Geomagic Studio 6.0 software were used to reconstruct the 3D morphology of bones and external soft tissue of the feet. The laterally wedge insole was designed in ProE 5.0. And then all the models were imported into Hyperwork 10.0 and meshed, and given the material properties. The finite element analysis was carried out in ABAQUS 6.9. A three-dimensional finite element model of the lower extremity was established, which was consisted of 95 365 nodes and 246 238 elements. The contact area of the standing state of the lower joint was larger than that of the anterior middle joint surface. The peak stress was concentrated in the anterior lateral part of the posterior articular surface, and the average stress value was(3.85±1.03) MPa. Compared with the model of 0°, the contact area of the subtalar joint was reduced accordingly. There was a significant correlation between anterior middle joint | r |=0.964, P =0.008, and posterior articular | r |=0.978, P =0.002. The equivalent stress of 0° model distributed from(3.07±1.14) MPa to(3.85± 1.03) MPa, which had no statistically difference. Compared with the 0° model, the equivalent stress of the anterior and middle joint surfaces of the 8° model was significantly reduced( P 0.05). Although a certain valgus can be obtained in subtalar by wearing LWI, the result comes at the cost of the stress concentration on posterior surface. Through this study, we can find that LWI with 8° tilt angle could provide appropriate valgus moment without causing excessive concentration. Therefore, in order to avoid secondary ankle complications, we should not increase the tilt angle blindly.

  9. Offshore deformation in the Calabrian accretionary wedge and implications for the 1693 Catania earthquake and tsunami (Eastern Sicily)

    Science.gov (United States)

    Gallais, F.; Gutscher, M.; Graindorge, D.; Polonia, A.

    2008-12-01

    Southern Italy has been struck repeatedly by very strong historical earthquakes as in 1169, 1693, 1783, 1905, 1908, often associated with destructive tsunami. While certain events (like 1908 Messina or 1783 Calabria) are associated with known crustal normal faults, which produced observed surface ruptures, the source of the strongest earthquake in the Italian catalog, the Catania earthquake of 1693 is still unknown. It may have been generated by the NW dipping subduction zone beneath Calabria and Eastern Sicily. Identifying its origin will have a major impact on the hazard assessment and our understanding of modern day tectonics in this region. The 1693 earthquake, struck E Sicily with intensities of X - XI and killed up to 60,000 people, destroying Catania, Syracuse and Augusta. It also generated a 5-10 m high tsunami which swept these cities. The 1169 earthquake had similar intensities (X to XI) and a similar isoseismal pattern, suggesting a similar source. Because of the tsunami generated in 1693 and because the isoseismals are open to the sea, the majority of the source region appears to be offshore. The nearby subduction fault plane is thus a strong candidate for both events. However, a lack of instrumentally recorded thrust earthquakes suggests that if subduction is active, the fault plane is locked (like Cascadia or Nankai). Reported GPS motions from the region are ambiguous, and thus the current activity of the Calabrian subduction remains a matter of debate. The offshore accretionary wedge is known from seismic and bathymetric investigations to include compressional anticlines and recently mud volcanoes have been discovered on the upper wedge. We present preliminary results from reprocessed 96-channel seismic reflection data from the 1997 French cruise Archimede (R/V Le Nadir) crossing the deformation front at the toe of the Calabrian prism, the Ionian abyssal plain and the deformation front of the Mediterranean Ridge (Hellenic subduction system). A more

  10. Selection and geographic isolation influence hummingbird speciation: genetic, acoustic and morphological divergence in the wedge-tailed sabrewing (Campylopterus curvipennis

    Directory of Open Access Journals (Sweden)

    Ornelas Juan

    2011-02-01

    Full Text Available Abstract Background Mesoamerica is one of the most threatened biodiversity hotspots in the world, yet we are far from understanding the geologic history and the processes driving population divergence and speciation for most endemic taxa. In species with highly differentiated populations selective and/or neutral factors can induce rapid changes to traits involved in mate choice, promoting reproductive isolation between allopatric populations that can eventually lead to speciation. We present the results of genetic differentiation, and explore drift and selection effects in promoting acoustic and morphological divergence among populations of Campylopterus curvipennis, a lekking hummingbird with an extraordinary vocal variability across Mesoamerica. Results Analyses of two mitochondrial genes and ten microsatellite loci genotyped for 160 individuals revealed the presence of three lineages with no contemporary gene flow: C. c. curvipennis, C. c. excellens, and C. c. pampa disjunctly distributed in the Sierra Madre Oriental, the Tuxtlas region and the Yucatan Peninsula, respectively. Sequence mtDNA and microsatellite data were congruent with two diversification events: an old vicariance event at the Isthmus of Tehuantepec (c. 1.4 Ma, and a more recent Pleistocene split, isolating populations in the Tuxtlas region. Hummingbirds of the excellens group were larger, and those of the pampa group had shorter bills, and lineages that have been isolated the longest shared fewer syllables and differed in spectral and temporal traits of a shared syllable. Coalescent simulations showed that fixation of song types has occurred faster than expected under neutrality but the null hypothesis that morphological divergence resulted from drift was not rejected. Conclusions Our phylogeographic analyses uncovered the presence of three Mesoamerican wedge-tailed sabrewing lineages, which diverged at different time scales. These results highlight the importance of the

  11. Flux closure during a substorm observed by Cluster, Double Star, IMAGE FUV, SuperDARN, and Greenland magnetometers

    Directory of Open Access Journals (Sweden)

    S. E. Milan

    2006-03-01

    Full Text Available We examine magnetic flux closure during an extended substorm interval on 29 August 2004 involving a two-stage onset and subsequent re-intensifications. Cluster and Double Star provide observations of magnetotail dynamics, while the corresponding auroral evolution, convection response, and substorm current wedge development are monitored by IMAGE FUV, SuperDARN, and the Greenland magnetometer chain, respectively. The first stage of onset is associated with the reconnection of closed flux in the plasma sheet; this is accompanied by a short-lived auroral intensification, a modest substorm current wedge magnetic bay, but no significant ionospheric convection enhancement. The second stage follows the progression of reconnection to the open field lines of the lobes; accompanied by prolonged auroral bulge and westward-travelling surge development, enhanced magnetic bays and convection. We find that the tail dynamics are highly influenced by ongoing dayside creation of open flux, leading to flux pile-up in the near-tail and a step-wise down-tail motion of the tail reconnection site. In all, 5 dipolarizations are observed, each associated with the closure of ~0.1 GWb of flux. Very simple calculations indicate that the X-line should progress down-tail at a speed of 20 km s-1, or 6 RE between each dipolarization.

  12. Flux closure during a substorm observed by Cluster, Double Star, IMAGE FUV, SuperDARN, and Greenland magnetometers

    Directory of Open Access Journals (Sweden)

    S. E. Milan

    2006-03-01

    Full Text Available We examine magnetic flux closure during an extended substorm interval on 29 August 2004 involving a two-stage onset and subsequent re-intensifications. Cluster and Double Star provide observations of magnetotail dynamics, while the corresponding auroral evolution, convection response, and substorm current wedge development are monitored by IMAGE FUV, SuperDARN, and the Greenland magnetometer chain, respectively. The first stage of onset is associated with the reconnection of closed flux in the plasma sheet; this is accompanied by a short-lived auroral intensification, a modest substorm current wedge magnetic bay, but no significant ionospheric convection enhancement. The second stage follows the progression of reconnection to the open field lines of the lobes; accompanied by prolonged auroral bulge and westward-travelling surge development, enhanced magnetic bays and convection. We find that the tail dynamics are highly influenced by ongoing dayside creation of open flux, leading to flux pile-up in the near-tail and a step-wise down-tail motion of the tail reconnection site. In all, 5 dipolarizations are observed, each associated with the closure of ~0.1 GWb of flux. Very simple calculations indicate that the X-line should progress down-tail at a speed of 20 km s-1, or 6 RE between each dipolarization.

  13. Hitchcock’s queer doubles

    Directory of Open Access Journals (Sweden)

    Alessandra Brandão

    2013-12-01

    Full Text Available http://dx.doi.org/10.5007/2175-8026.2013n65p17   The “double” is a well-known Hitchcockian motif. Widelyreviewed under a psychoanalytical perspective, the issue ofthe double still presents other important challenges and thisarticle aims at discussing the queer doubles in Hitchcock’s films as “falsifiers” who are opposed to non-queer doubles thatemphasise narrative coherence and legibility. In films such asRebeca, Rope, Vertigo, The Birds, Psycho, and Frenzy, a doublecondenses impulses that are well described by Lee Edelman: “theviolent undoing of meaning, the loss of identity and coherence,the unnatural access to jouissance” (132. These doubles releasethe powers of the false as they complicate the return to an “order”.Therefore, we could argue that such characters are closer tobeing Deleuzian simulacra than psychoanalytical doppelgängers.

  14. Species doubling and effective Lagrangians

    Energy Technology Data Exchange (ETDEWEB)

    Creutz, M.; Tytgat, M.

    1996-09-01

    Coupling gauge fields to the chiral currents from an effective Lagrangian for pseudoscalar mesons naturally gives rise to a species doubling phenomenon similar to that seen with fermionic fields in lattice gauge theory. 17 refs.

  15. The Double Love Commandment

    Directory of Open Access Journals (Sweden)

    Francois P. Viljoen

    2015-03-01

    Full Text Available The Gospel of Matthew was written during a period of dispute between the Matthean community and their fellow Jews, with the Pharisees playing a leading role. The Matthean community was heir to the same scriptures as its opponents. They continued to have a firm commitment to the Torah, but they developed a distinctive understanding of it based on Jesus’ teaching. The formation of this community is investigated in this article, considering the Mediterranean perspectives of group-oriented societies prevalent in the first century. Such a group provided a sense of self and an interactive support system, where love functioned to bind the group together. The subordinates showed their undivided loyalty towards their superiors because of the favours they received from them, whilst they supported and cared for other members within the group as they care for themselves. Reading the double love commandment of Matthew 22:34−40 from this perspective reveals significant aspects of the community’s identity with regard to their commitment to God and their view of their neighbours. Die Dubbele Liefdesgebod. Die Matteusevangelie is gedurende ’n periode van konfliktussen die Matteusgemeenskap en mede-Jode geskryf met die Fariseërs in ’n leidende rol. Die Matteusgemeenskap het van dieselfde geskrifte as hulle opponente gebruik gemaak. Hulle was steeds aan die Torah lojaal, maar het ’n unieke interpretasie daarvan gehuldig, gebaseer op die onderrig van Jesus. In hierdie artikel word die vorming van die Matteusgemeenskap ondersoek met inagneming van die Mediterreense beskouing van die groepgeoriënteerde gemeenskappe wat tipies van die eerste eeu was. So ’n groep het aan individue ’n bewustheid van eie waarde verskaf te midde van ’n interaktiewe ondersteuningsisteem waarin liefde as samebindende faktor gefunksioneer het. Ondergeskiktes het onverdeelde lojaliteit teenoor hulle meerderes betoon vanweë die gunste wat hulle van die meerderes geniet het

  16. The Double Love Commandment

    Directory of Open Access Journals (Sweden)

    Francois P. Viljoen

    2015-03-01

    Full Text Available The Gospel of Matthew was written during a period of dispute between the Matthean community and their fellow Jews, with the Pharisees playing a leading role. The Matthean community was heir to the same scriptures as its opponents. They continued to have a firm commitment to the Torah, but they developed a distinctive understanding of it based on Jesus’ teaching. The formation of this community is investigated in this article, considering the Mediterranean perspectives of group-oriented societies prevalent in the first century. Such a group provided a sense of self and an interactive support system, where love functioned to bind the group together. The subordinates showed their undivided loyalty towards their superiors because of the favours they received from them, whilst they supported and cared for other members within the group as they care for themselves. Reading the double love commandment of Matthew 22:34−40 from this perspective reveals significant aspects of the community’s identity with regard to their commitment to God and their view of their neighbours.Die Dubbele Liefdesgebod. Die Matteusevangelie is gedurende ’n periode van konfliktussen die Matteusgemeenskap en mede-Jode geskryf met die Fariseërs in ’n leidende rol. Die Matteusgemeenskap het van dieselfde geskrifte as hulle opponente gebruik gemaak. Hulle was steeds aan die Torah lojaal, maar het ’n unieke interpretasie daarvan gehuldig, gebaseer op die onderrig van Jesus. In hierdie artikel word die vorming van die Matteusgemeenskap ondersoek met inagneming van die Mediterreense beskouing van die groepgeoriënteerde gemeenskappe wat tipies van die eerste eeu was. So ’n groep het aan individue ’n bewustheid van eie waarde verskaf te midde van ’n interaktiewe ondersteuningsisteem waarin liefde as samebindende faktor gefunksioneer het. Ondergeskiktes het onverdeelde lojaliteit teenoor hulle meerderes betoon vanweë die gunste wat hulle van die meerderes geniet het

  17. Effect of thermal radiation and suction on convective heat transfer of nanofluid along a wedge in the presence of heat generation/absorption

    Energy Technology Data Exchange (ETDEWEB)

    Kasmani, Ruhaila Md; Bhuvaneswari, M. [Centre for Foundation Studies in Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Sivasankaran, S.; Siri, Zailan [Institute of Mathematical Science, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2015-10-22

    An analysis is presented to find the effects of thermal radiation and heat generation/absorption on convection heat transfer of nanofluid past a wedge in the presence of wall suction. The governing partial differential equations are transformed into a system of ordinary differential equations using similarity transformation. The resulting system is solved numerically using a fourth-order Runge–Kutta method with shooting technique. Numerical computations are carried out for different values of dimensionless parameters to predict the effects of wedge angle, thermophoresis, Brownian motion, heat generation/absorption, thermal radiation and suction. It is found that the temperature increases significantly when the value of the heat generation/absorption parameter increases. But the opposite observation is found for the effect of thermal radiation.

  18. Keepers of the Double Stars

    OpenAIRE

    Tenn, Joseph S.

    2013-01-01

    Astronomers have long tracked double stars in efforts to find those that are gravitationally-bound binaries and then to determine their orbits. Early catalogues by the Herschels, Struves, and others began with their own discoveries. In 1906 court reporter and amateur astronomer Sherburne Wesley Burnham published a massive double star catalogue containing data from many observers on more than 13,000 systems. Lick Observatory astronomer Robert Grant Aitken produced a much larger catalogue in 19...

  19. Double parton scattering in CMS

    CERN Document Server

    Sunar Cerci, Deniz

    2017-01-01

    Recent results on the double parton scattering measurements performed using the proton-proton collision data collected with the CMS detector are presented. The observables, which are sensitive to double parton scattering, are investigated after being corrected for detector effects and selection efficiencies. Multivariate analysis techniques are used for increasing the sensitivity. The effective cross section, $\\sigma_{eff}$ is also extracted using different processes at various center-of-mass energies.

  20. Supermagic Generalized Double Graphs 1

    Directory of Open Access Journals (Sweden)

    Ivančo Jaroslav

    2016-02-01

    Full Text Available A graph G is called supermagic if it admits a labelling of the edges by pairwise di erent consecutive integers such that the sum of the labels of the edges incident with a vertex is independent of the particular vertex. In this paper we will introduce some constructions of supermagic labellings of some graphs generalizing double graphs. Inter alia we show that the double graphs of regular Hamiltonian graphs and some circulant graphs are supermagic.

  1. Medial opening-wedge high tibial osteotomy fixation with short plate without any graft, synthetic material or spacer.

    Science.gov (United States)

    Türkmen, Faik; Sever, Cem; Kacıra, Burkay K; Demirayak, Mehmet; Acar, Mehmet Ali; Toker, Serdar

    2014-12-01

    Medial opening-wedge high tibial osteotomy (MOWHTO) is an effective surgical procedure for patients who have medial compartmental osteoarthritis of the knee with varus deformity of the limb. The abnormal load on the medial compartment of the knee is directed to the lateral compartment with this procedure. A gap occurs on the proximal tibia while providing adequate correction. Filling this gap with bone grafts or synthetic materials has gained wide acceptance for preventing bone union problems or osteotomy site collapse. The aim of this study is to report our results of MOWHTOs performed without any bone graft or any other synthetic materials. We evaluated 41 MOWHTOs that have been performed between 2009 and 2012 with no use of any grafts or synthetic materials and spacer. Age of the patients ranged from 43 to 67. Thirty-five of the patients were females and three of them were males. The follow-up time was 6 months. Seven knees had opening at the osteotomy site 12.5 mm (range 7.5-14 mm, mean 11.07 mm). All osteotomies united without loss of correction. The mean bone union time was 12.8 weeks. We did not have any major complication regarding the technique. The results of our study have shown that we can achieve satisfactory and good results by performing MOWHTO procedure without using any bone grafts or synthetic materials and spacer.

  2. Medial Opening Wedge High Tibial Osteotomy Fixation with Short Plate without any Graft, Synthetic Material or Spacer

    Science.gov (United States)

    Türkmen, Faik; Sever, Cem; Kacıra, Burkay Kutluhan; Demirayak, Mehmet; Acar, Mehmet Ali; Toker, Serdar

    2014-01-01

    Objectives: Medial opening-wedge high tibial osteotomy (MOWHTO) is an effective surgical procedure for patients who have medial compartmental osteoarthritis of the knee with varus deformity of the limb. The abnormal load on the medial compartment of the knee relocates to the lateral compartment with this procedure. A gap occurs on the proximal tibia during the correction of varus deformity. Filling this gap with bone grafts or synthetic materials has gained wide acceptance for preventing nonunion or osteotomy site collapse. The aim of this study is to report our results of MOWHTOs performed without any bone graft or any other synthetic materials. Methods: We evaluated 41 MOWHTOs performed between 2009 and 2012 with no use of bone grafts, synthetic materials or spacers. Age of the patients ranged from 43 to 67. Thirty five of the patients were female and 3 of them were male. The follow-up time was 6 months. Results: There were no any non-unions or loss of correction. The mean bone union time was 12,8 weeks. No major complications were seen. Conclusion: The results of our study has shown that achieve satisfactory results can be obtained in MOWHTO without using any bone graft, synthetic materials or spacer.

  3. Effects of an intradialytic resistance training programme on physical function: a prospective stepped-wedge randomized controlled trial.

    Science.gov (United States)

    Bennett, Paul Norman; Fraser, Steve; Barnard, Robert; Haines, Terry; Ockerby, Cherene; Street, Maryann; Wang, Wei Chun; Daly, Robin

    2016-08-01

    Intradialytic exercise programmes are important because of the deterioration in physical function that occurs in people receiving haemodialysis. Unfortunately, exercise programmes are rarely sustained in haemodialysis clinics. The aim of this study was to determine the efficacy of a sustainable resistance exercise programme on the physical function of people receiving haemodialysis. A total of 171 participants from 15 community satellite haemodialysis clinics performed progressive resistance training using resistance elastic bands in a seated position during the first hour of haemodialysis treatment. We used a stepped-wedge design of three groups, each containing five randomly allocated cluster units allocated to an intervention of 12, 24 or 36 weeks. The primary outcome measure was objective physical function measured by the 30-s sit-to-stand (STS) test, the 8-foot timed up and go (TUG) test and the four-square step test. Secondary outcome measures included quality of life, involvement in community activity, blood pressure and self-reported falls. Exercise training led to significant improvements in physical function as measured by STS and TUG. There was a significant average downward change (β = -1.59, P training can improve the physical function of people receiving dialysis. © The Author 2015. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

  4. Implications for management and conservation of the population genetic structure of the wedge clam Donax trunculus across two biogeographic boundaries

    Science.gov (United States)

    Marie, Amandine D.; Lejeusne, Christophe; Karapatsiou, Evgenia; Cuesta, José A.; Drake, Pilar; MacPherson, Enrique; Bernatchez, Louis; Rico, Ciro

    2016-12-01

    In a resource management perspective, the understanding of the relative influence of the physical factors on species connectivity remains a major challenge and is also of great ecological and conservation biology interest. Despite the overfishing threat on the wedge clam Donax trunculus in Europe, relatively little information is known about its population genetic structure and connectivity and their consequences on conservation policies. We employed 16 microsatellite loci to characterise the genetic diversity and population structure of D. trunculus. A total of 514 samples from seven different localities along the Atlantic-Mediterranean transition, from the Atlantic (Gulf of Cádiz) to the north-western Mediterranean were genotyped. The analysis of the population genetic structure displayed a clear distinction along the Atlantic-Mediterranean transition with different clusters in the Atlantic Ocean, the Alboran Sea and the northwestern Mediterranean. Consequently, we recommend that these three areas should be considered as different management units. We showed that all populations seem to be at high long-term risk of extinction with the exception of the protected Doñana National Park population which still seems to have evolutionary potential. Therefore, our results emphasized the necessity of protection of this economic resource and the validity of molecular tools to evaluate the population dynamics.

  5. Death with "dignity": the wedge that divides the disability rights movement from the right to die movement.

    Science.gov (United States)

    Behuniak, Susan M

    2011-01-01

    Much of the American debate over physician assisted death (PAD) is framed as an ideological split between conservatives and liberals, pro life and pro choice advocates, and those who emphasize morality versus personal autonomy. Less examined, but no less relevant, is a split within the ranks of progressives--one that divides those supporting a right to die in the name of human rights from disability rights activists who invoke human rights to vehemently oppose euthanasia. This paper reviews how "dignity" serves both as a divisive wedge in this debate but also as a value that can span the divide between groups and open the way to productive discourse. Supporters of legalized euthanasia use "dignity" to express their position that some deaths might indeed be accelerated. At the same time, opponents adopt the concept to argue that physician assisted suicide stigmatizes life with a disability. To bridge this divide, the worldviews of two groups, Compassion & Choices and Not Dead Yet, are studied. The analysis concludes that the two organizations are more parallel than contrary--a finding that offers opportunities for dialogue and perhaps even advances in public policy.

  6. Changes in estimating echocardiography pulmonary capillary wedge pressure after hypersaline plus furosemide versus furosemide alone in decompensated heart failure.

    Science.gov (United States)

    Parrinello, Gaspare; Paterna, Salvatore; Di Pasquale, Pietro; Torres, Daniele; Mezzero, Manuela; Cardillo, Mauro; Fasullo, Sergio; La Rocca, Gabriella; Licata, Giuseppe

    2011-04-01

    The aim of the study was to verify the effects of hypertonic saline solution (HSS) plus a high furosemide dose and light restriction of sodium intake compared with a high-dose infusion of furosemide alone on pulmonary capillary wedge pressure (PCWP), as determined by Doppler echocardiography and tissue Doppler imaging in patients suffering from decompensated heart failure. Consecutive patients in New York Heart Association functional class IV, unresponsive to oral high doses of furosemide up to 250-500 mg/d and/or combinations of diuretics, with ejection fraction function was significantly improved in the HSS group. Both groups showed a significant reduction in Echo-PCWP, but the HHS group revealed a faster reduction and significant lower values at 6 days compared with the group taking furosemide alone. We observed a positive correlation between values of Echo-PCWP and BNP and an inverse correlation between BIA parameters and Echo-PCWP. Our data show that the combination of high diuretic dose and HSS infusion plus light restriction in dietary sodium intake determine a more rapid and significant hemodynamic stabilization through the improvement of echo-PCWP, BNP levels, and BIA parameters than the group treated without HSS. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. MHD boundary layer radiative, heat generating and chemical reacting flow past a wedge moving in a nanofluid.

    Science.gov (United States)

    Khan, Md Shakhaoath; Karim, Ifsana; Islam, Md Sirajul; Wahiduzzaman, Mohammad

    2014-01-01

    The present study analyzed numerically magneto-hydrodynamics (MHD) laminar boundary layer flow past a wedge with the influence of thermal radiation, heat generation and chemical reaction. This model used for the momentum, temperature and concentration fields. The principal governing equations is based on the velocity u w (x) in a nanofluid and with a parallel free stream velocity u e (x) and surface temperature and concentration. Similarity transformations are used to transform the governing nonlinear boundary layer equations for momentum, thermal energy and concentration to a system of nonlinear ordinary coupled differential equations with fitting boundary conditions. The transmuted model is shown to be controlled by a number of thermo-physical parameters, viz. the magnetic parameter, thermal convective parameter, mass convective parameter, radiation-conduction parameter, heat generation parameter, Prandtl number, Lewis number, Brownian motion parameter, thermophoresis parameter, chemical reaction parameter and pressure gradient parameter. Numerical elucidations are obtained with the legendary Nactsheim-Swigert shooting technique together with Runge-Kutta six order iteration schemes. Comparisons with previously published work are accomplished and proven an excellent agreement.

  8. Interference of wedge-shaped protrusions on the faces of a Griffith crack in biaxial stress. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Boulet, J.A.M. [Tennessee Univ., Knoxville, TN (United States)

    1992-04-01

    An initial investigation of the influence of protrusion interference on the fracture toughness required to prevent unstable propagation of a Griffith crack in a brittle material is described. The interference is caused by relative shear displacement of the crack faces when subjected to remote biaxial stress with neither principal stress parallel to the crack. It is shown that for room temperature cracks smaller than about one centimeter in silicon carbide, or about one millimeter in silicon nitride, the presence of interference changes the fracture stress. A mathematical model based on linear elasticity solutions and including multiple interference sites at arbitrarily specified positions on the crack is presented. Computations of the change in required fracture toughness and its dependence on wedge geometry (size and vertex angle), applied stresses (orientation and magnitude), and location of the interference site are discussed. Results indicate that a single interference site has only a slight effect on required toughness. However, the influence of interference increases monotonically with the number of interference sites. The two-dimensional model described herein is not accurate when the interference sites are closely spaced.

  9. Evaluation of portal hypertension: a comparison of the use of liver perfusion CT with wedge hepatic venous pressure and hepatic

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Dong Jin; Kim, Young Joong; Park, Yong Sung; Lee, Tae Hee [University of Konyang College of Medicine, Daejeon (Korea, Republic of); Kim, Chong Soo; Kang, Heung Keun [Chonbuk National University Medical School, Jeonju (Korea, Republic of)

    2008-09-15

    We compared the hepatic perfusion indices obtained using hepatic perfusion CT with the wedge hepatic venous pressure (WHVP) and hepatic venous pressure gradient (HVPG) to determine the efficacy of the use of liver perfusion CT for the evaluation of portal hypertension. Thirty-five patients with liver cirrhosis underwent hepatic vein catheterization to measure WHVP and HVPG and underwent a liver perfusion CT examination. Arterial perfusion, portal perfusion, total perfusion and the hepatic perfusion index (HPI) were calculated by the methods described by Miles and Blomlely. The overall correlation coefficients (r) between the perfusion indices and WHVP and HVPG were calculated. An additional correlation coefficient of 23 alcoholic cirrhosis patients was calculated. Using Blomley's equation, HPI had a positive correlation with WHVP (r = .471; {rho} < .05) and HVPG (r = .482; {rho} < .05). For the alcoholic liver cirrhosis patients, HPI had a higher positive correlation with WHVP (r = .500; {rho} < .05) and HVPG (r = .539; {rho} < .05) than for the non-alcoholic cirrhosis patients. There was no statistical difference between the use of Miles' equation and Blomley's equation for the evaluation of portal hypertension. This preliminary study showed that HPI positively correlated with WHVP and HVPG, especially in alcoholic cirrhosis patients. Liver perfusion CT may be useful in the evaluation of portal hypertension.

  10. Minimally invasive opening wedge tibia outpatient osteotomy, using screw-to-plate locking technique and a calcium phosphate cement.

    Science.gov (United States)

    Schwartz, Claude

    2018-01-10

    Medial knee osteoarthritis on angular varus deformity of a lower limb is very common. Open-wedge high tibial osteotomy is a treatment of choice if cartilage is not excessively worn (Allback 1 or 2). The technique based on a plate fixation and the bone defect filled with calcium phosphate cement is thoroughly described. Data at 1, 3, 6 months and 1 year of a 19 cases continuous and prospective series are collected and analysed. Mean age at the time of operation was 55 years. The average preoperative varus deformity was 5° and corrected to an average postoperative valgus of 4° (range 3°-6°). Each control includes the collection of eventual complications, the measurement of health status (quality of life and functional scores) and antero-posterior and lateral X-rays. All osteotomies were considered healed at 6 weeks without any correction loss except one, probably result of a technical error. There was no difference in clinical and functional results between the group and the literature, but the final result occurred earlier in the treatment when the bone defect was filled with either calcium phosphate cement. Faster recovery involved no specific complication and enabled outpatient treatment in a majority of patients.

  11. Development of method to remove weld scallop and ceramic backing material of wedge type and its application

    Science.gov (United States)

    Kang, Sung-Koo; Yang, Jong-Soo; Kim, Ho-Kyung

    2015-06-01

    The weld scallop has been used for joining T-bars. There are a lot of weld scallops in shipbuilding. It is difficult to perform scallop welding due to the inconvenient welding position. This results in many problems such as porosity, slag inclusion, etc. In this study, a new method is devised to remove weld scallops by incorporating a Ceramic Backing Material (CBM). The weld scallop is removed by an elongation of the v groove. In order to insert a CBM into the groove without a weld scallop, a wedge-shaped CBM is developed. The top side of the developed CBM is similar to the shape of a general back bead. The bottom surface has a saw-toothed shape for cutting at a suitable length. This can be attached to the root side of a face plate using adhesive tape, just like a general CBM. Welding experiments in normal and abnormal conditions are carried out and the possibility of burn-through is examined. This CBM's applicability to shipbuilding is verified.

  12. Development of method to remove weld scallop and ceramic backing material of wedge type and its application

    Directory of Open Access Journals (Sweden)

    Sung-Koo Kang

    2015-03-01

    Full Text Available The weld scallop has been used for joining T-bars. There are a lot of weld scallops in shipbuilding. It is difficult to perform scallop welding due to the inconvenient welding position. This results in many problems such as porosity, slag inclusion, etc. In this study, a new method is devised to remove weld scallops by incorporating a Ceramic Backing Material (CBM. The weld scallop is removed by an elongation of the v groove. In order to insert a CBM into the groove without a weld scallop, a wedge-shaped CBM is developed. The top side of the developed CBM is similar to the shape of a general back bead. The bottom surface has a saw-toothed shape for cutting at a suitable length. This can be attached to the root side of a face plate using adhesive tape, just like a general CBM. Welding experiments in normal and abnormal conditions are carried out and the possibility of burn-through is examined. This CBM’s applicability to shipbuilding is verified.

  13. Launching a salt substitute to reduce blood pressure at the population level: a cluster randomized stepped wedge trial in Peru.

    Science.gov (United States)

    Bernabe-Ortiz, Antonio; Diez-Canseco, Francisco; Gilman, Robert H; Cárdenas, María K; Sacksteder, Katherine A; Miranda, J Jaime

    2014-03-25

    Controlling hypertension rates and maintaining normal blood pressure, particularly in resource-constrained settings, represent ongoing challenges of effective and affordable implementation in health care. One of the strategies being largely advocated to improve high blood pressure calls for salt reduction strategies. This study aims to estimate the impact of a population-level intervention based on sodium reduction and potassium increase - in practice, introducing a low-sodium, high-potassium salt substitute - on adult blood pressure levels. The proposed implementation research study includes two components: Phase 1, an exploratory component, and Phase 2, an intervention component. The exploratory component involves a triangle taste test and a formative research study designed to gain an understanding of the best implementation methods. Phase 2 involves a pragmatic stepped wedge trial design where the intervention will be progressively implemented in several clusters starting the intervention randomly at different times. In addition, we will evaluate the implementation strategy using a cost-effectiveness analysis. This is the first project in a Latin-American setting to implement a salt substitution intervention at the population level to tackle high blood pressure. Data generated and lessons learnt from this study will provide a strong platform to address potential interventions applicable to other similar low- and middle-income settings. This study is registered in ClinicalTrials.gov NCT01960972.

  14. Effect of viscous dissipation and suction/injection on MHD nanofluid flow over a wedge with porous medium and slip

    Directory of Open Access Journals (Sweden)

    Alok Kumar Pandey

    2016-12-01

    Full Text Available The purpose of present study is to identify the effects of viscous dissipation and suction/injection on MHD flow of a nanofluid past a wedge with convective surface in the appearance of slip flow and porous medium. The basic non-linear PDEs of flow and energy are altered into a set of non-linear ODEs using auxiliary similarity transformations. The system of equations together with coupled boundary conditions have been solved numerically by applying Runge-Kutta-Fehlberg procedure via shooting scheme. The influence of relevant parameters on non-dimensional velocity and temperature profiles are depicted graphically and investigated in detail. The results elucidate that as enhance in the Eckert number, the skin friction coefficient increases, while heat transfer rate decreases. The outcomes also specify that thermal boundary layer thickness declines with an increase in suction parameter. Moreover, it is accelerated with augment in injection parameter. The results are analogized with the study published earlier and it creates a fine concord.

  15. The 4 January 2016 Manipur earthquake in the Indo-Burmese wedge, an intra-slab event

    Directory of Open Access Journals (Sweden)

    V. K. Gahalaut

    2016-09-01

    Full Text Available Earthquakes in the Indo-Burmese wedge occur due to India-Sunda plate motion. These earthquakes generally occur at depth between 25 and 150 km and define an eastward gently dipping seismicity trend surface that coincides with the Indian slab. Although this feature mimics the subduction zone, the relative motion of Indian plate predominantly towards north, earthquake focal mechanisms suggest that these earthquakes are of intra-slab type which occur on steep plane within the Indian plate. The relative motion between the India and Sunda plates is accommodated at the Churachandpur-Mao fault (CMF and Sagaing Fault. The 4 January 2016 Manipur earthquake (M 6.7 is one such earthquake which occurred 20 km west of the CMF at ∼60 km depth. Fortunately, this earthquake occurred in a very sparse population region with very traditional wooden frame houses and hence, the damage caused by the earthquake in the source region was very minimal. However, in the neighbouring Imphal valley, it caused some damage to the buildings and loss of eight lives. The damage in Imphal valley due to this and historical earthquakes in the region emphasizes the role of local site effect in the Imphal valley.

  16. Effects of a free school breakfast programme on school attendance, achievement, psychosocial function, and nutrition: a stepped wedge cluster randomised trial

    OpenAIRE

    Maddison Ralph; Michie Jo; Jiang Yannan; Gorton Delvina; Turley Maria; Ni Mhurchu Cliona; Hattie John

    2010-01-01

    Abstract Background Approximately 55,000 children in New Zealand do not eat breakfast on any given day. Regular breakfast skipping has been associated with poor diets, higher body mass index, and adverse effects on children's behaviour and academic performance. Research suggests that regular breakfast consumption can improve academic performance, nutrition and behaviour. This paper describes the protocol for a stepped wedge cluster randomised trial of a free school breakfast programme. The ai...

  17. [Effects of different tooth preparations on the fracture behavior of teeth with severe wedge-shaped defect restored with post and core crowns].

    Science.gov (United States)

    Feng, Dandan; Qi, Dong; Lin, Xuefen; Ding, Tingting; Ji, Ping

    2014-04-01

    This study aimed to investigate the effects of different tooth preparations on the fracture strength and pattern of failure of teeth with severe wedge-shaped defect restored with post and core crowns. According to whether the teeth above the wedge-shaped defect was removed (represented by B) or not (represented by A), the ferrule next to the wedge-shaped defect was prepared (represented by D) or not (represented by C), the cast post-and-core was chosen (represented by E) or glass-fiber post and resin core was chosen (represented by F). A total of 64 human mandibular premolar teeth were randomly divided into 8 groups: A1-1 (A + C + E), A1-2 (A + C + F), A2-1 (A + D + E), A2-2 (A + D + F), B1-1 (B + C + E), B1-2 (B + C + F), B2-1 (B + D + E), B2-2 (B + D + F), each group 8 teeth. All the teeth were prepared and restored accordingly and then mounted on an electronic pressure universal testing machine. The maximum fracture strength and the patterns of failure were recorded. 1) The fracture strength of Group A1-1 > that of Group B1-1, Group A1-2 > Group B1-2, Group B2-1 > Group B1-1, and Group B2-1 > Group B2-2 with significant differences (P crown. The ferrule of the wedge-shaped defect is not recommended to be prepared. Furthermore, the glass-fiber post and resin core is favorable for the re-repair of the teeth than the cast post and core.

  18. Shear wave splitting and the dynamics of the hydrated mantle wedge in subduction regions constrained by the example of the Ryukyu subduction zone

    Science.gov (United States)

    Nagaya, T.; Walker, A.; Wookey, J. M.; Wallis, S.; Ishii, K.; Kendall, J. M.

    2016-12-01

    H2O-rich subduction fluids are a key component of convergent plate margin dynamics, essential to earthquake initiation and magma formation. These fluids in the wedge mantle are dominantly derived from antigorite dragged down by plate motion. However, the accurate distribution of antigorite-rich serpentinite related to the fluid transport in subduction zones has thus far been difficult to determine. Our approach is to model the S-wave splitting of the Ryukyu arc in order to constrain the distribution, amount and orientation of antigorite, while taking into account the geometry of seismic ray paths and the elastic anisotropy of deformed antigorite-bearing mantle. We have also carried out a full assessment of uncertainties associated with our analysis including time delay estimates from the seismic waves themselves, crustal anisotropy, averaging schemes for CPO, and the strength of antigorite CPO patterns. The results suggest the presence of a large-scale flow in the hydrous mantle with a low viscosity and more than 54% of this domain consists of antigorite. Other geophysical observations in the forearc mantle including the low seismic velocity and gravity anomaly are also compatible with our inference of the presence of induced flow in an antigorite-rich, hydrated mantle wedge in the Ryukyu arc. We have also constructed a geodynamic model to examine flow patterns in the hydrated shallow wedge mantle using the distribution and proportion of serpentinite derived from our seismic model and subduction parameters that are close to those of the arc. The results clearly show that convection occurs in the serpentinized mantle wedge and that this domain is associated with a low surface heat flow. S-wave splitting observations in other subduction zones implies this large-scale serpentinization and hydrous mantle flow is likely to be more widespread than generally recognized and the view that the forearc mantle of cold subduction zones lacks significant zones of hydration needs

  19. Fluid Replacement Monitoring: Effect of Dextran Overload, Norepinephrine Drip, and Positive Pressure Ventilation on Systemic Arterial, Right Atrial Pulmonary Wedge, and Left Atrial Pressures in Dogs

    Science.gov (United States)

    Hardy, James D.; Garcia, Jose B.; Hardy, Julia A.; Harkins, Mitchell H.

    1974-01-01

    The effects of dextran overload, norepinephrine drip and positive pressure ventilation upon right atrial, pulmonary wedge, left atrial and systemic arterial pressures were studied in 15 dogs. Rapid intravenous infusion of Dextran 70 invariably produced a marked and statistically significant (p < .001) rise in right atrial, pulmonary wedge and left atrial pressures. The rise in left atrial pressure invariably exceeded the rise in right atrial pressure, and the difference in maximum pressures averaged 10.8 mm Hg (p < .001). Thus acute fluid overload and pulmonary edema can be produced by rapid infusion of colloid solution in the absence of a marked rise in right atrial pressure, a point of considerable clinical importance. The rapid infusion of dextran produced a rise in systemic arterial blood pressure in all dogs so studied, though this rise was mild in some animals. This finding may explain in part the hypertension exhibited by patients in the recovery room who may have been overtransfused. A norepinephrine drip usually produced an increase in right atrial, wedge, left atrial and systemic arterial blood pressure (p < .01). When there was a significant rise in right atrial pressure and left atrial pressure, the maximum increase in left atrial pressure was always greater than the maximum increase in right atrial pressure (p < .005). This finding again emphasizes the fact that blood transfusion requirements cannot always be accurately assessed on the basis of right and left atrial pressure measurements when a vasopressor agent is being administered. Positive pressure ventilation increased both right and left atrial pressures, as expected. It was again confirmed that pulmonary wedge pressure, as measured with the Swan-Ganz catheter, is approximately equal to left atrial pressure over a wide range of induced variations. The Swan-Ganz catheter, introduced at the bedside in the intensive care unit when necessary, can provide highly useful information regarding left

  20. Kinetic and kinematic changes with the use of valgus knee brace and lateral wedge insoles in patients with medial knee osteoarthritis.

    Science.gov (United States)

    Fantini Pagani, Cynthia H; Hinrichs, Maren; Brüggemann, Gert-Peter

    2012-07-01

    The effect of a valgus knee brace and a lateral wedged insole on knee and ankle kinematics and kinetics was evaluated in ten patients with medial knee osteoarthritis (OA). The knee orthosis was tested in two valgus adjustments (4° and 8°), and the laterally wedged insole was fabricated with an inclination of 4°. A motion capture system and force platforms were used for data collection and joint moments were calculated using inverse dynamics. The valgus moment applied by the orthosis was also measured using a strain gauge implemented in the orthosis' rotational axis. For the second peak knee adduction moment, decreases of 18%, 21%, and 7% were observed between baseline and test conditions for the orthosis in 4° valgus, in 8° valgus, and insole, respectively. Similar decreases were observed for knee lever arm in the frontal plane. Knee adduction angular impulse decreased 14%, 18%, and 7% from baseline to conditions for the orthosis in 4° valgus, in 8° valgus, and insole, respectively. Knee angle in the frontal plane reached a more valgus position during gait using the valgus knee brace. The valgus moment applied by the orthosis with 8° valgus adjustment was 30% higher than with 4° valgus adjustment. The valgus knee orthosis was more effective than the laterally wedged insole in reducing knee adduction moment in patients with medial knee OA. Copyright © 2011 Orthopaedic Research Society.

  1. Studying the effect of medial open wedge high tibial osteotomy on the posterior slope of tibia among patients with Genu varum

    Directory of Open Access Journals (Sweden)

    Seyyed Raza Sharifzadeh

    2017-09-01

    Full Text Available Background A slight change in the posterior slope of tibia results in complications such as limited movement of knee joint and higher risks of Osteoarthritis. Aims The present research seeks to study levels of tibia’s posterior slope change and limited movement of knee joint and knee stability following medial open wedge osteotomy used to treat patients with genu varum. Methods The present research is a clinical trial conducted in the form of a before and after study on patients with genu varum resorting to Imam Reza (PBUH, Khanevade, and Fajr hospitals from 2009 to 2012. As many as 40 knees (32 patients were studied and the posterior slope of tibia before and after medial open wedge high tibial osteotomy was measured by someone totally unaware of the research using true lateral radiography. Movement limitation and stability of the knee was measured before and after the operation using scope of motion and Lachman and Drawer test. Paired sample test was used in this research and SPSS was used to analyse the data. Results The average posterior slope of tibia before the operation was 9.912, while this value changed to 11.625 after the operation signifying a significant increase. In terms of limited knee joint movement, 7 patients were diagnosed with grade 5 Extension LAG after operation, while the remaining 33 patients had a normal motion range (Extension LAG=0. Conclusion Medial open wedge osteotomy above tibia can help increase the posterior slope of tibia.

  2. Alternate Double Single Track Lines

    Energy Technology Data Exchange (ETDEWEB)

    Moraga Contreras, P.; Grande Andrade, Z.; Castillo Ron, E.

    2016-07-01

    The paper discusses the advantages and shortcomings of alternate double single track (ADST) lines with respect to double track lines for high speed lines. ADST lines consists of sequences of double and single track segments optimally selected in order to reduce the construction and maintenance costs of railway lines and to optimize the timetables used to satisfy a given demand. The single tracks are selected to coincide with expensive segments (tunnels and viaducts) and the double tracks are chosen to coincide with flat areas and only where they are necessary. At the same time, departure times are adjusted for trains to cross at the cheap double track segments. This alternative can be used for new lines and also for existing conventional lines where some new tracks are to be constructed to reduce travel time (increase speed). The ADST proposal is illustrated with some examples of both types (new lines and where conventional lines exist), including the Palencia-Santander, the Santiago-Valparaíso-Viña del Mar and the Dublin-Belfast lines, where very important reductions (90 %) are obtained, especially where a railway infrastructure already exist. (Author)

  3. Azeglio Bemporad and the "BEM" Double Stars

    Science.gov (United States)

    Smith, Steven; Prunotto, Marco

    2017-07-01

    This paper aims to describe the scientific context and the life of early 20th century Italian astronomer Azeglio Bemporad (1875-1945), his work on double stars, and how the “BEM” doubles were incorporated into the Washington Double Star catalog. Included are new measures, a complete photo gallery of all 61 of his double star systems, and copies of his double star publications.

  4. Do laterally wedged insoles or valgus braces unload the medial compartment of the knee in patients with osteoarthritis?

    Science.gov (United States)

    Duivenvoorden, Tijs; van Raaij, Tom M; Horemans, Herwin L D; Brouwer, Reinoud W; Bos, P Koen; Bierma-Zeinstra, Sita M A; Verhaar, Jan A N; Reijman, Max

    2015-01-01

    The results of conservative treatment of knee osteoarthritis (OA) are generally evaluated in epidemiological studies with clinical outcome measures as primary outcomes. Biomechanical evaluation of orthoses shows that there are potentially beneficial biomechanical changes to joint loading; however, evaluation in relation to clinical outcome measures in longitudinal studies is needed. We asked (1) is there an immediate effect on gait in patients using a laterally wedged insole or valgus knee brace; (2) is there a late (6 weeks) effect; and (3) is there a difference between subgroups within each group with respect to patient compliance, body mass index, and OA status? This was a secondary analysis of data from a previous randomized controlled trial of patients with early medial knee OA. A total of 91 patients were enrolled in that trial, and 73 (80%) completed it after 6 months. Of the enrolled patients, 80 (88%) met prespecified inclusion criteria for analysis in the present study. The patients were randomized to an insole or brace. Gait was analyzed with and without wearing the orthosis (insole or brace) at baseline and after 6 weeks. Measurements were taken of the knee adduction moment, ground reaction force, moment arm, walking speed, and toe-out angle. Data were analyzed with regression analyses based on an intention-to-treat principle. A mean reduction of 4% (±10) (95% confidence interval [CI], -0.147 to -0.03, p=0.003) of the peak knee adduction moment and 4% (±13) (95% CI, -0.009 to -0.001, p=0.01) of the moment arm at baseline was observed in the insole group when walking with an insole was compared with walking without an insole. A mean reduction of 1% (±10) (95% CI, -0.002 to -0.001, p=0.001) of the peak knee adduction moment and no reduction of the moment arm were measured after 6 weeks. No reduction of knee adduction moment, moment arm, or ground reaction force was seen in the brace group at baseline and after 6 weeks. Subgroup analysis showed no

  5. Serial Changes in the Joint Space Width and Joint Line Convergence Angle After Closed-Wedge High Tibial Osteotomy.

    Science.gov (United States)

    Park, Cheol Hee; Bae, Dae Kyung; Kim, Kang Il; Lee, Jong Whan; Song, Sang Jun

    2017-12-01

    There have been little data concerning serial changes in the joint space width (JSW) and joint line convergence angle over the course of follow-up periods after closed-wedge high tibial osteotomy (CWHTO). To evaluate serial changes in the JSW and joint line convergence angle after CWHTO. Case series; Level of evidence, 4. A total of 100 computer-assisted CWHTOs with a minimum follow-up period of 3 years (mean, 4.4 years) were analyzed. Clinically, the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score was evaluated. Radiographically, the mechanical axis was measured preoperatively and postoperatively. The minimal JSW was measured as the shortest distance between the femur and the tibia. The convergence angle was measured as the angle between the tangent to the subchondral plates of the femoral condyle and the tibial plateau. Serial changes in these measurements were analyzed preoperatively; at 3 months, 6 months, 1 year, and 2 years postoperatively; and at the final follow-up. The intraclass correlation coefficients for all measurements were greater than 0.8. The mean WOMAC score improved from 41.4 preoperatively to 14.9 at the final follow-up. The preoperative and postoperative mean mechanical axis was 8.1° varus and 1.6° valgus, respectively. The mean minimal JSW was 2.5, 2.9, 2.9, 3.1, 3.2, and 3.1 mm preoperatively and at 3 months, 6 months, 1 year, 2 years, and the final follow-up, respectively ( P angle was 4.4°, 3.9°, 4.0°, 4.1°, 4.2°, and 4.3°, respectively, during the same time periods ( P = .068). Cartilage healing, as indicated by the JSW, and clinical improvement were maintained over the minimum 3-year follow-up after CWHTO. Cartilage pressure, as indicated by the convergence angle, remained unchanged after CWHTO.

  6. A multimodal intervention to improve hand hygiene in ICUs in Buenos Aires, Argentina: a stepped wedge trial.

    Science.gov (United States)

    Rodriguez, Viviana; Giuffre, Carolina; Villa, Silvia; Almada, Griselda; Prasopa-Plaizier, Nittita; Gogna, Monica; Gibbons, Luz; García Elorrio, Ezequiel

    2015-10-01

    Hand hygiene is a cost-effective measure to reduce microbial transmission (Teare EL, Cookson B, French GL, et al. UK handwashing initiative. J Hosp Infect. 1999;43:1-3.) and is considered to be the most important measure to prevent healthcare-associated infections (Pittet D, Allegranzi B, Sax H, Evidence-based model for hand transmission during patient care and the role of improved practices. Lancet Infect Dis 2006;6:641-52). Unfortunately, the compliance rate of healthcare workers (HCWs) with recommended hand hygiene procedures is less than expected. In order to estimate the effect of a multimodal intervention on improving healthcare workers' compliance with hand hygiene in eleven intensive care units (ICUs) from 11 hospitals of Buenos Aires, a randomized cluster-stepped wedge trial was designed. A multimodal intervention was designed based on practices characterized by being evidence-based, low cost and suggested by qualitative research: (i) leadership commitment, (ii) surveillance of materials needed to comply with hand hygiene and alcohol consumption, (iii) utilization of reminders, (iv) a storyboard of the project and (v) feedback (hand hygiene compliance rate). The study enrolled 705 participants, comprising nurses (66.4%), physicians (25.8%) and other HCW (7.8%) along 9 months of observation. Compliance with hand hygiene in the control group was 66.0% (2354/3565) vs. 75.6% (5190/6864) in the intervention group. Univariate analysis showed an association between the intervention and hand hygiene compliance (odds ratio, OR 1.17; 95% confidence interval (CI), 1.13-1.22). The effect was still present after adjustment by calendar's time and providers' characteristics-age, gender and profession (OR 1.08; 95% CI, 1.03-1.14). His study supports that a multimodal intervention was effective to improve compliance with hand hygiene in ICUs. © The Author 2015. Published by Oxford University Press in association with the International Society for Quality in Health Care

  7. Coronal subluxation of the proximal tibia relative to the distal femur after opening wedge high tibial osteotomy.

    Science.gov (United States)

    Akamatsu, Yasushi; Ohno, Satoshi; Kobayashi, Hideo; Kusayama, Yoshihiro; Kumagai, Ken; Saito, Tomoyuki

    2017-01-01

    The coronal subluxation of the proximal tibia relative to the distal femur is a common radiological finding in patients with knee osteoarthritis. The purpose was to evaluate whether the coronal subluxation was corrected after opening wedge high tibial osteotomy (OWHTO), and whether this subluxation was one cause of inconsistency between the actual and predicted alignments (correction loss). Fifty-one patients (55 knees) were treated with OWHTO. The change of location between the intersection points of the femoral and tibial axes on the tibial plateau (subluxation-C), the change of location between the lines through the most lateral points of the lateral femoral and tibial condyles (subluxation-L), and joint space angle (JSA) were compared in standing knee radiographs before and one year after OWHTO. The subluxation-C and subluxation-L were converted to a percentage of the tibial plateau width. The mean subluxation-C of 6.5% before OWHTO significantly increased to a mean subluxation-C of 7.3% one year after OWHTO. The mean subluxation-L of 6.3% and JSA of 4.5° before OWHTO significantly decreased to a subluxation-L of 1.8% and JSA of 3.3° one year after OWHTO. The change in subluxation-L correlated with the change in femorotibial angle and correction loss (r=0.634, Pfemur after OWHTO. This medial shift correlated with the correction loss. The coronal subluxation might be one cause of correction loss. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. Bivergent thrust wedges surrounding oceanic island arcs: Insight from observations and sandbox models of the northeastern caribbean plate

    Science.gov (United States)

    ten Brink, Uri S.; Marshak, S.; Granja, Bruna J. L.

    2009-01-01

    At several localities around the world, thrust belts have developed on both sides of oceanic island arcs (e.g., Java-Timor, Panama, Vanuatu, and the northeastern Caribbean). In these localities, the overall vergence of the backarc thrust belt is opposite to that of the forearc thrust belt. For example, in the northeastern Caribbean, a north-verging accretionary prism lies to the north of the Eastern Greater Antilles arc (Hispaniola and Puerto Rico), whereas a south-verging thrust belt called the Muertos thrust belt lies to the south. Researchers have attributed such bivergent geometry to several processes, including: reversal of subduction polarity; subduction-driven mantle flow; stress transmission across the arc; gravitational spreading of the arc; and magmatic inflation within the arc. New observations of deformational features in the Muertos thrust belt and of fault geometries produced in sandbox kinematic models, along with examination of published studies of island arcs, lead to the conclusion that the bivergence of thrusting in island arcs can develop without reversal of subduction polarity, without subarc mantle flow, and without magmatic inflation. We suggest that the Eastern Greater Antilles arc and comparable arcs are simply crustalscale bivergent (or "doubly vergent") thrust wedges formed during unidirectional subduction. Sandbox kinematic modeling suggests, in addition, that a broad retrowedge containing an imbricate fan of thrusts develops only where the arc behaves relatively rigidly. In such cases, the arc acts as a backstop that transmits compressive stress into the backarc region. Further, modeling shows that when arcs behave as rigid blocks, the strike-slip component of oblique convergence is accommodated entirely within the prowedge and the arc-the retrowedge hosts only dip-slip faulting ("frontal thrusting"). The existence of large retrowedges and the distribution of faulting in an island arc may, therefore, be evidence that the arc is

  9. Physical micro-environment interventions for healthier eating in the workplace: protocol for a stepped wedge randomised controlled pilot trial.

    Science.gov (United States)

    Vasiljevic, Milica; Cartwright, Emma; Pechey, Rachel; Hollands, Gareth J; Couturier, Dominique-Laurent; Jebb, Susan A; Marteau, Theresa M

    2017-01-01

    An estimated one third of energy is consumed in the workplace. The workplace is therefore an important context in which to reduce energy consumption to tackle the high rates of overweight and obesity in the general population. Altering environmental cues for food selection and consumption-physical micro-environment or 'choice architecture' interventions-has the potential to reduce energy intake. The first aim of this pilot trial is to estimate the potential impact upon energy purchased of three such environmental cues (size of portions, packages and tableware; availability of healthier vs. less healthy options; and energy labelling) in workplace cafeterias. A second aim of this pilot trial is to examine the feasibility of recruiting eligible worksites, and identify barriers to the feasibility and acceptability of implementing the interventions in preparation for a larger trial. Eighteen worksite cafeterias in England will be assigned to one of three intervention groups to assess the impact on energy purchased of altering (a) portion, package and tableware size (n = 6); (b) availability of healthier options (n = 6); and (c) energy (calorie) labelling (n = 6). Using a stepped wedge design, sites will implement allocated interventions at different time periods, as randomised. This pilot trial will examine the feasibility of recruiting eligible worksites, and the feasibility and acceptability of implementing the interventions in preparation for a larger trial. In addition, a series of linear mixed models will be used to estimate the impact of each intervention on total energy (calories) purchased per time frame of analysis (daily or weekly) controlling for the total sales/transactions adjusted for calendar time and with random effects for worksite. These analyses will allow an estimate of an effect size of each of the three proposed interventions, which will form the basis of the sample size calculations necessary for a larger trial. ISRCTN52923504.

  10. High efficient coupling between wedged-shaped fiber and planar lightwave circuit chip using gradient refractive-index media

    Science.gov (United States)

    Liu, Xu; Qu, Shuting; Xiao, Jinbiao; Sun, Xiaohan

    2006-10-01

    Planar lightwave circuit (PLC) chips based on III-V semiconductor MQW rib waveguide promise to be not only a solution to information access, but also direct the issues of bandwidth, pin count, reliability and complexity. Nanopositioning and precision alignment addresses vital importance in high-efficient connectivity between PLC chips and fiber arrays. Refractive-index mismatching between fused silica and III-V compound is one of the most serious problem which remains unsolved on one hand as well as mode field mismatching which can be mitigated in other hand through gradient geometry structure such as tapered spot size converter (SSC) and specialty fibers such as wedge-shaped fiber (WSF). Spherical gradient refractive-index (SGRIN) media intervened between WSF and MQW rib waveguide is put forward. The GRIN media virtually eliminates the reflection losses associated with the fused silica-air interface and III-V semiconductor-air interface. The beam spot emitted from WSF are observed by digital camera and the fundamental mode of MQW rib waveguide was calculated out. Lightwave propagation and mode field evolution in the WSF-SGRIN-PLC system is simulated by FDTD method with the coupling loss of 8.54dB at a wavelength of 1.55μm. An LED signal is injected into WSF, transmitted along GRIN media and PLC waveguide and output through single mode fiber (SMF). Optical power meter-based measurement verifies the whole system coupling loss to be consistent with the numeric estimation. The approach provides an experimental prototype for coupling and packaging technique of integrated photonic devices, hence supplying foundation for photonic network.

  11. Immediate and long-term efficacy of laterally-wedged insoles on persons with bilateral medial knee osteoarthritis during walking.

    Science.gov (United States)

    Hsu, Wei-Chun; Jhong, You-Cai; Chen, Hao-Ling; Lin, Yi-Jia; Chen, Li-Fei; Hsieh, Lin-Fen

    2015-05-14

    The current study aimed to investigate the immediate and long-term effects of laterally-wedged (LW) insoles on the knee loadings, the knee abductor moment (KAM) in particular, and the compensatory changes at other lower limb joints in patients with bilateral medial knee osteoarthritis during level walking with and without LW insoles. Older adults with bilateral medial knee OA (age 66 ± 5.3 years; height 156 ± 4.9 cm; mass 60 ± 5.1 kg; leg length 83.72 ± 3.64 cm) were studied using computerized gait analysis initially (Baseline) and 6 weeks after using LW insoles (Follow-up) during barefoot walking and walking with LW insoles (7° of lateral inclination, with medial arch support). The three-dimensional angles and internal moments at the lower limb joints, as well as the ground reaction forces, were obtained using a motion analysis system and two forceplates. Key features of all the variables were compared using paired t tests for immediate effects (barefoot vs. LW) and for long-term effects (Baseline vs. Follow-up). The symptomatic severity (WOMAC Index) was also evaluated (Baseline vs. Follow-up). The KAM with LW insoles at Baseline was significantly reduced when compared to the barefoot condition (p 0.05), when compared to Baseline with LW insoles. However, a specific gait adaptation with reduced knee loading was revealed when walking without LW insoles, i.e., for the barefoot condition (p physical function were improved with decreased peak KAM. A specific gait adaptation with reduced KAM was also found when walking without LW insoles. These results indicate a positive long-term effect in persons with bilateral medial knee OA, both as an orthosis to assist walking, and as a treatment intervention to facilitate gait adaptations in favor of reduced KAM.

  12. Patient-reported outcomes correlate with functional scores after opening-wedge high tibial osteotomy: a clinical study.

    Science.gov (United States)

    Han, Seung-Beom; Lee, Jong-Hee; Kim, Seul-Gi; Cui, Chun-Guang; Suh, Dong-Won; Lee, Seung-Yup; Jang, Ki-Mo

    2017-08-21

    The purpose of this study was to assess post-operative patient subjective satisfaction and to analyze associated peri-operative factors following biplanar medial open wedge high tibial osteotomy (OWHTO). The study cohort consisted of 88 patients with a minimum of two years of follow-up. Patient satisfaction was evaluated with a questionnaire that assessed (1) overall satisfaction, (2) pain relief, (3) daily living functions, and (4) cosmesis. Patients were categorized into two groups (satisfied or unsatisfied) based on overall satisfaction questionnaire. Pre- and post-operative objective clinical statuses were assessed with a knee scoring system based on the American Knee Society (AKS), the Western Ontario McMaster University Osteoarthritis Index (WOMAC), and range of motion. Of the 88 patients, 85.2% were graded as satisfied according to the overall satisfaction estimation. The percentage of patients satisfied with pain relief, daily living functions, and cosmesis were 85.2%, 86.4%, and 86.4%, respectively. Multivariable logistic regression analysis demonstrated that pre-operative Hip-Knee-Ankle angle (HKAA) (odds ratio (OR) = 1.812), post-operative AKS knee score (OR = 1.156), and post-operative HKAA (OR = 0.717) were significantly associated with overall satisfaction. Pre-operative HKAA (OR = 1.436), post-operative WOMAC activity score (OR = 0.865), and post-operative HKAA (OR = 0.505) were significant predictors for satisfaction with pain reduction, daily living functions, and cosmesis, respectively. Biplanar medial OWHTO is an effective treatment for osteoarthritis with varus deformity in terms of subjective satisfactory outcome. Several factors, including pre- and post-operative HKAA, post-operative AKS and WOMAC score, were significant predictors for subjective satisfaction. Level III.

  13. Complex social intervention for multidisciplinary teams to improve patient referrals in obstetrical care: protocol for a stepped wedge study design.

    Science.gov (United States)

    Romijn, Anita; de Bruijne, Martine C; Teunissen, Pim W; de Groot, Christianne J M; Wagner, Cordula

    2016-07-14

    In obstetrics, patients often experience referral situations between different care professionals. In these multidisciplinary teams, a focus on communication and interprofessional collaboration is needed to ensure care of high quality. Crew resource management team training is increasingly being applied in healthcare settings to improve team performance and coordination. Efforts to improve communication also include tools for standardisation such as SBAR (situation, background, assessment, recommendation). Despite the growing adoption of these interventions, evidence on their effectiveness is limited, especially on patient outcomes. This article describes a study protocol to examine the effectiveness of a crew resource management team training intervention aimed at implementing the SBAR tool for structured communication during patient referrals in obstetrical care. The intervention is rolled out sequentially in five hospitals and surrounding primary care midwifery practices in the Netherlands, using a stepped wedge design. The intervention involves three phases over a period of 24 months: (1) preparation, (2) training and (3) follow-up with repeated measurements. The primary outcomes are perinatal and maternal outcomes calculated using the Adverse Outcome Index. The secondary outcomes are the reaction of participating professionals to the training programme, attitudes towards safety and teamwork (Safety Attitudes Questionnaire), cohesion (Interprofessional Collaboration Measurement Scale), use of the tool for structured communication (self-reported questionnaire) and patient experiences. These secondary outcomes from professional and patient level allow triangulation and an increased understanding of the effect of the intervention on patient outcomes. The study was approved by the Medical Ethical Committee of the VU University Medical Centre in the Netherlands and the protocol is in accordance with Dutch privacy regulations. Study findings will be presented in

  14. The extended wedge method: Atomic force microscope friction calibration for improved tolerance to instrument misalignments, tip offset, and blunt probes

    Science.gov (United States)

    Khare, H. S.; Burris, D. L.

    2013-05-01

    One of the major challenges in understanding and controlling friction is the difficulty in bridging the length and time scales of macroscale contacts and those of the single asperity interactions they comprise. While the atomic force microscope (AFM) offers a unique ability to probe tribological surfaces in a wear-free single-asperity contact, instrument calibration challenges have limited the usefulness of this technique for quantitative nanotribological studies. A number of lateral force calibration techniques have been proposed and used, but none has gained universal acceptance due to practical considerations, configuration limitations, or sensitivities to unknowable error sources. This paper describes a simple extension of the classic wedge method of AFM lateral force calibration which: (1) allows simultaneous calibration and measurement on any substrate, thus eliminating prior tip damage and confounding effects of instrument setup adjustments; (2) is insensitive to adhesion, PSD cross-talk, transducer/piezo-tube axis misalignment, and shear-center offset; (3) is applicable to integrated tips and colloidal probes; and (4) is generally applicable to any reciprocating friction coefficient measurement. The method was applied to AFM measurements of polished carbon (99.999% graphite) and single crystal MoS2 to demonstrate the technique. Carbon and single crystal MoS2 had friction coefficients of μ = 0.20 ± 0.04 and μ = 0.006 ± 0.001, respectively, against an integrated Si probe. Against a glass colloidal sphere, MoS2 had a friction coefficient of μ = 0.005 ± 0.001. Generally, the measurement uncertainties ranged from 10%-20% and were driven by the effect of actual frictional variation on the calibration rather than calibration error itself (i.e., due to misalignment, tip-offset, or probe radius).

  15. Impact on Prehospital Delay of a Stroke Preparedness Campaign: A SW-RCT (Stepped-Wedge Cluster Randomized Controlled Trial).

    Science.gov (United States)

    Denti, Licia; Caminiti, Caterina; Scoditti, Umberto; Zini, Andrea; Malferrari, Giovanni; Zedde, Maria Luisa; Guidetti, Donata; Baratti, Mario; Vaghi, Luca; Montanari, Enrico; Marcomini, Barbara; Riva, Silvia; Iezzi, Elisa; Castellini, Paola; Olivato, Silvia; Barbi, Filippo; Perticaroli, Eva; Monaco, Daniela; Iafelice, Ilaria; Bigliardi, Guido; Vandelli, Laura; Guareschi, Angelica; Artoni, Andrea; Zanferrari, Carla; Schulz, Peter J

    2017-12-01

    Public campaigns to increase stroke preparedness have been tested in different contexts, showing contradictory results. We evaluated the effectiveness of a stroke campaign, designed specifically for the Italian population in reducing prehospital delay. According to an SW-RCT (Stepped-Wedge Cluster Randomized Controlled Trial) design, the campaign was launched in 4 provinces in the northern part of the region Emilia Romagna at 3-month intervals in randomized sequence. The units of analysis were the patients admitted to hospital, with stroke and transient ischemic attack, over a time period of 15 months, beginning 3 months before the intervention was launched in the first province to allow for baseline data collection. The proportion of early arrivals (within 2 hours of symptom onset) was the primary outcome. Thrombolysis rate and some behavioral end points were the secondary outcomes. Data were analyzed using a fixed-effect model, adjusting for cluster and time trends. We enrolled 1622 patients, 912 exposed and 710 nonexposed to the campaign. The proportion of early access was nonsignificantly lower in exposed patients (354 [38.8%] versus 315 [44.4%]; adjusted odds ratio, 0.81; 95% confidence interval, 0.60-1.08; P=0.15). As for secondary end points, an increase was found for stroke recognition, which approximated but did not reach statistical significance (P=0.07). Our campaign was not effective in reducing prehospital delay. Even if some limitations of the intervention, mainly in terms of duration, are taken into account, our study demonstrates that new communication strategies should be tested before large-scale implementation. URL: http://www.clinicaltrials.gov. Unique identifier: NCT01881152. © 2017 American Heart Association, Inc.

  16. The 'Expanded HIV care in opioid substitution treatment' (EHOST) cluster-randomized, stepped-wedge trial: A study protocol.

    Science.gov (United States)

    Nosyk, B; Krebs, E; Min, J E; Ahamad, K; Buxton, J; Goldsmith, C; Hull, M; Joe, R; Krajden, M; Lima, V D; Olding, M; Wood, E; Montaner, J S G

    2015-11-01

    The public health response to HIV/AIDS has turned its focus onto optimizing health care system delivery to maximize case identification, access and sustained engagement in antiretroviral treatment (ART). Opioid Agonist Treatment (OAT) provides a critical opportunity for HIV testing and linkage to ART. The EHOST study is a cluster-randomized, stepped-wedge trial to evaluate a prescriber-focused intervention to increase HIV testing rates, and optimize ART engagement and retention outcomes among individuals engaged in OAT. The study will encompass all drug treatment clinics currently admitting patients for the treatment of opioid use disorder across the province of British Columbia, encompassing an estimated 90% of the OAT caseload. The trial will be executed over a 24-month period, with groups of clinics receiving the intervention in 6-month intervals. Evaluation of the proposed intervention's effectiveness will focus on three primary outcomes: (i) the HIV testing rate among those not known to be HIV positive; (ii) the rate of ART initiation among those not on ART; and (iii) the rate of ART continuation among those on ART. A difference-in-differences analytical framework will be applied to estimate the intervention's effect. This approach will assess site-specific changes in primary outcomes across clusters while adjusting for potential residual heterogeneity in patient case mix, volume, and quality of care across clinics. Statistical analysis of outcomes will be conducted entirely with linked population-level administrative health datasets. Facilitated by established collaborations between key stakeholders across the province, the EHOST intervention promises to optimize HIV testing and care within a marginalized and hard-to-reach population. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. The Doubling Undone? Double Effect in Recent Medical Ethics ...

    African Journals Online (AJOL)

    This article treats recent bioethical discussions of double effect reasoning (DER), offering a summary account of DER and construing it as rooted in a sensible view of what is central to someone's identity as a moral agent. It then treats objections raised in recent years by Judith Thomson, Alison McIntyre, and Frances Kamm ...

  18. Doubled-ended ceramic thyratron

    CERN Multimedia

    1974-01-01

    The double-ended ceramic thyratron CX 1171 B, with its coaxial voltage divider for the SPS. Such a switch, paralleled by three ignitrons in series forms the "thyragnitron" arrangement, and can switch 10 kA, 25 ms pulses, with very fast rise times.

  19. Magnetoresistance stories of double perovskites

    Indian Academy of Sciences (India)

    out. Keywords. Tunnelling magnetoresistance; tunnel boundary; disorder; double perovskite. PACS Nos 75.47.−m; 73.40.Gk; 72.80.Ga. 1. Introduction. Magnetoresistance (MR) is the property of a material to change the value of its electri- cal resistance when an external magnetic field is applied. This phenomenon was first.

  20. Double Coffee opens in China

    Index Scriptorium Estoniae

    2009-01-01

    Läti suursaadik Ingrida Levrence avas esimese Double Coffee kohviku Hiina pealinnas Pekingi südames. Rahvusvaheline kohvikukett kavatseb laieneda mõne kohviku võrra igal aastal. Seni tegutsetakse Lätis, Eestis, Leedus, Ukrainas ja Valgevenes