WorldWideScience

Sample records for bidimensional wedge domains

  1. Image denoising in bidimensional empirical mode decomposition domain: the role of Student's probability distribution function.

    Science.gov (United States)

    Lahmiri, Salim

    2016-03-01

    Hybridisation of the bi-dimensional empirical mode decomposition (BEMD) with denoising techniques has been proposed in the literature as an effective approach for image denoising. In this Letter, the Student's probability density function is introduced in the computation of the mean envelope of the data during the BEMD sifting process to make it robust to values that are far from the mean. The resulting BEMD is denoted tBEMD. In order to show the effectiveness of the tBEMD, several image denoising techniques in tBEMD domain are employed; namely, fourth order partial differential equation (PDE), linear complex diffusion process (LCDP), non-linear complex diffusion process (NLCDP), and the discrete wavelet transform (DWT). Two biomedical images and a standard digital image were considered for experiments. The original images were corrupted with additive Gaussian noise with three different levels. Based on peak-signal-to-noise ratio, the experimental results show that PDE, LCDP, NLCDP, and DWT all perform better in the tBEMD than in the classical BEMD domain. It is also found that tBEMD is faster than classical BEMD when the noise level is low. When it is high, the computational cost in terms of processing time is similar. The effectiveness of the presented approach makes it promising for clinical applications.

  2. Bidimensionality and EPTAS

    CERN Document Server

    Fomin, Fedor V; Raman, Venkatesh; Saurabh, Saket

    2010-01-01

    Bidimensionality theory is a powerful framework for the development of metaalgorithmic techniques. It was introduced by Demaine et al. as a tool to obtain sub-exponential time parameterized algorithms for problems on H-minor free graphs. Demaine and Hajiaghayi extended the theory to obtain PTASs for bidimensional problems, and subsequently improved these results to EPTASs. Fomin et. al related the theory to the existence of linear kernels for parameterized problems. In this paper we revisit bidimensionality theory from the perspective of approximation algorithms and redesign the framework for obtaining EPTASs to be more powerful, easier to apply and easier to understand. Two of the most widely used approaches to obtain PTASs on planar graphs are the Lipton-Tarjan separator based approach, and Baker's approach. Demaine and Hajiaghayi strengthened both approaches using bidimensionality and obtained EPTASs for a multitude of problems. We unify the two strenghtened approaches to combine the best of both worlds. A...

  3. Bidimensionality and Geometric Graphs

    CERN Document Server

    Fomin, Fedor V; Saurabh, Saket

    2011-01-01

    In this paper we use several of the key ideas from Bidimensionality to give a new generic approach to design EPTASs and subexponential time parameterized algorithms for problems on classes of graphs which are not minor closed, but instead exhibit a geometric structure. In particular we present EPTASs and subexponential time parameterized algorithms for Feedback Vertex Set, Vertex Cover, Connected Vertex Cover, Diamond Hitting Set, on map graphs and unit disk graphs, and for Cycle Packing and Minimum-Vertex Feedback Edge Set on unit disk graphs. Our results are based on the recent decomposition theorems proved by Fomin et al [SODA 2011], and our algorithms work directly on the input graph. Thus it is not necessary to compute the geometric representations of the input graph. To the best of our knowledge, these results are previously unknown, with the exception of the EPTAS and a subexponential time parameterized algorithm on unit disk graphs for Vertex Cover, which were obtained by Marx [ESA 2005] and Alber and...

  4. 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

  5. A property of the bidimensional sphere

    CERN Document Server

    Cavachi, Marius

    2011-01-01

    It is natural to ask for a reasonable constant k having the property that any open set of area greater than k on a bidimensional sphere of area 1 always contains the vertices of a regular tetrahedron. We shall prove that it is sufficient to take k=3/4. In fact we shall prove a more general result. The interested reader will not have any problem in establishing that 3/4 is the best constant with this property.

  6. 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.

  7. Floating rings in vertical soap films : capillary driven bidimensional buoyancy

    CERN Document Server

    Adami, N

    2013-01-01

    The present study aims to investigate the motion of buoyant rings in vertical soap films. Thickness differences and related bi-dimensional densities are considered as the motor leading to bi-dimensional buoyancy. We show how this effect can be re-interpreted thanks to surface tension profiles in soap films. We propose a model involving surface tension profiles in order to describe the motion of buoyant particles in vertical soap films, and compare it to experimental data.

  8. Experimental Observation of Kink in a Perfect Bidimensional Granular System

    Institute of Scientific and Technical Information of China (English)

    ZHANG Peng; MIAO Guo-Qing; HUANG Kai; YUN Yi; WEI Rong-Jue

    2005-01-01

    @@ The kink formation in a vertical vibrated granular layer has been widely studied in three-dimensional systems, but there are few if any experimental reports on bidimensional granular layers. We report the kink formation newly found in a perfect bidimensional granular system. We measure the range of the driving frequencies and dimensionless accelerations for kinks. Furthermore, we observe a heaping process, which is caused by co-operative action of the kink-associated convection and the sidewall-associated convection.

  9. La estadística bidimensional en 4º ESO

    OpenAIRE

    Astarriaga Ros, Amaia

    2012-01-01

    Este trabajo fin de máster tiene como objetivo estudiar la enseñanza de la estadística bidimensional en 4º de ESO. El trabajo se estructura en dos partes. En la primera parte se realiza un estudio longitudinal del currículo y en los libros de texto en Primaria, en ESO y en Bachillerato con relación al tema indicado. En la segunda parte se propone un proceso de estudio sobre estadística bidimensional, que se ha puesto en marcha en un aula de 4º de ESO en el marco del Pract...

  10. 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

  11. Wedges of Anxiety

    DEFF Research Database (Denmark)

    Hellström, Maria; Brandt, Eva

    2005-01-01

    The Heraclitian notion of a reality in constant flux seems to have settled even in the public consciousness. We are, to an ever-increasing extent, on the move; in motion between different places of abode, between domiciles and places of residence, between temporary addresses and provisory settlem...... cones of light, as the cut their way into the unknown, like wedges of anxiety...

  12. Shock detachment from curved wedges

    Science.gov (United States)

    Mölder, S.

    2017-03-01

    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.

  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. Single Photon Avalanche Diodes: Towards the Large Bidimensional Arrays

    Science.gov (United States)

    Privitera, Simona; Tudisco, Salvatore; Lanzanò, Luca; Musumeci, Francesco; Pluchino, Alessandro; Scordino, Agata; Campisi, Angelo; Cosentino, Luigi; Finocchiaro, Paolo; Condorelli, Giovanni; Mazzillo, Massimo; Lombardo, Salvo; Sciacca, Emilio

    2008-01-01

    Single photon detection is one of the most challenging goals of photonics. In recent years, the study of ultra-fast and/or low-intensity phenomena has received renewed attention from the academic and industrial communities. Intense research activity has been focused on bio-imaging applications, bio-luminescence, bio-scattering methods, and, more in general, on several applications requiring high speed operation and high timing resolution. In this paper we present design and characterization of bi-dimensional arrays of a next generation of single photon avalanche diodes (SPADs). Single photon sensitivity, dark noise, afterpulsing and timing resolution of the single SPAD have been examined in several experimental conditions. Moreover, the effects arising from their integration and the readout mode have also been deeply investigated. PMID:27873777

  15. Single Photon Avalanche Diodes: Towards the Large Bidimensional Arrays

    Directory of Open Access Journals (Sweden)

    Emilio Sciacca

    2008-08-01

    Full Text Available Single photon detection is one of the most challenging goals of photonics. In recent years, the study of ultra-fast and/or low-intensity phenomena has received renewed attention from the academic and industrial communities. Intense research activity has been focused on bio-imaging applications, bio-luminescence, bio-scattering methods, and, more in general, on several applications requiring high speed operation and high timing resolution. In this paper we present design and characterization of bi-dimensional arrays of a next generation of single photon avalanche diodes (SPADs. Single photon sensitivity, dark noise, afterpulsing and timing resolution of the single SPAD have been examined in several experimental conditions. Moreover, the effects arising from their integration and the readout mode have also been deeply investigated.

  16. On Bi-Dimensional Second µ-Variation

    Directory of Open Access Journals (Sweden)

    Ereú Jurancy

    2014-12-01

    Full Text Available In this paper, we present a generalization of the notion of bounded slope variation for functions defined on a rectangle Iba in ℝ2. Given a strictly increasing function µ-defined in a closed real interval, we introduce the class BVµ,2 (Iba , of functions of bounded second µ-variation on Iba ; and show that this class can be equipped with a norm with respect to which it is a Banach space. We also deal with the important case of factorizable functions in BVµ,2 (Iba and finally we exhibit a relation between this class and the one of double Riemann-Stieltjes integrals of functions of bi-dimensional bounded variation.

  17. Heat string model of bi-dimensional dc Glidarc

    Science.gov (United States)

    Pellerin, S.; Richard, F.; Chapelle, J.; Cormier, J.-M.; Musiol, K.

    2000-10-01

    The gliding arc discharge (`Glidarc') is the subject of renewed interest in application to a variety of chemical reactions. The gliding arc creates a weakly ionized gas `string' between two horn-shaped electrodes. In this paper, we present a simple model for a bi-dimensional dc Glidarc working in air, in which the conducting zone of the discharge that is heated by the Joule effect is considered as a hot wire cooled by an air flow. Inside this wire, the heat transfer results from thermal conduction. The exchange of heat between the hot wire and the air flow is assured by convection and depends on the wire radius and the relative velocity of the arc with respect to the gas flow. The model correctly describes experimental results and allows us to predict the working parameters of the Glidarc in different experimental situations.

  18. Cross-validating a bidimensional mathematics anxiety scale.

    Science.gov (United States)

    Haiyan Bai

    2011-03-01

    The psychometric properties of a 14-item bidimensional Mathematics Anxiety Scale-Revised (MAS-R) were empirically cross-validated with two independent samples consisting of 647 secondary school students. An exploratory factor analysis on the scale yielded strong construct validity with a clear two-factor structure. The results from a confirmatory factor analysis indicated an excellent model-fit (χ(2) = 98.32, df = 62; normed fit index = .92, comparative fit index = .97; root mean square error of approximation = .04). The internal consistency (.85), test-retest reliability (.71), interfactor correlation (.26, p anxiety. Math anxiety, as measured by MAS-R, correlated negatively with student achievement scores (r = -.38), suggesting that MAS-R may be a useful tool for classroom teachers and other educational personnel tasked with identifying students at risk of reduced math achievement because of anxiety.

  19. Implementation of a bidimensional compressor for a high-energy physics experiment

    CERN Document Server

    Antinori, S; Gabrielli, A; Gandolfi, E

    2004-01-01

    CARLOSv3 is the third version of a chip that plays a significant role in the data acquisition chain of the A Large Ion Collider Experiment (ALICE) silicon drift detector (SDD). ALICE is one of the foremost high-energy physics experiments (HEPE) conducted within the Large Hadron Collider at CERN, the European Organization for Nuclear Research in Geneva. CARLOSv3 was principally designed and built for the on-line compression of the input dataset originating from a physical bidimensional silicon sensor. To compress a bidimensional dataset, a bidimensional data compressor was required. The compressor was designed for the ALICE SDD Experiment but could be applied to all experiments in which an incoming stream dataset originates from a bidimensional sensor. (20 refs).

  20. BattRAE: Bidimensional Attention-Based Recursive Autoencoders for Learning Bilingual Phrase Embeddings

    OpenAIRE

    Zhang, Biao; Xiong, Deyi; Su, Jinsong

    2016-01-01

    In this paper, we propose a bidimensional attention based recursive autoencoder (BattRAE) to integrate clues and sourcetarget interactions at multiple levels of granularity into bilingual phrase representations. We employ recursive autoencoders to generate tree structures of phrases with embeddings at different levels of granularity (e.g., words, sub-phrases and phrases). Over these embeddings on the source and target side, we introduce a bidimensional attention network to learn their interac...

  1. Bidimensional distortion in ferroelectric liquid crystals with strong anchoring in bookshelf geometry

    Indian Academy of Sciences (India)

    S Ponti; M Becchi; A Strigazzi; S Torgova

    2003-08-01

    In the last decade, it has been experimentally found that in certain conditions a periodic domain pattern arises in ferroelectric liquid crystals (FLC) in bookshelf geometry. Such a periodic texture appears after switching-off an external electric field, even in strong anchoring conditions. It has a static character and is bidimensional, being dependent on directions normal to both the smectic planes and the cell plates. Here a new model explaining this phenomenon is proposed, valid in the case of FLC with strong anchoring. The model is based on the coupling between the spontaneous polarization field in the first semi-period of its modulation along the cell plates and the same field in the second semi-period. This coupling competes with the FLC medium elasticity and is trapped by the anchoring. According to our model, in the ferroelectric state the biperiodic texture is favored by increasing the values of spontaneous polarization. The critical value of the spontaneous polarization for which the undeformed state becomes unstable is found. It is shown to be proportional to the square root of the ratio between the FLC elastic constant and the cell thickness. Moreover, it is inversely proportional to the sinus of the pre-tilt angle with respect to the cell walls.

  2. Evaluating Pavement Cracks with Bidimensional Empirical Mode Decomposition

    Directory of Open Access Journals (Sweden)

    Nii Attoh-Okine

    2008-05-01

    Full Text Available Crack evaluation is essential for effective classification of pavement cracks. Digital images of pavement cracks have been analyzed using techniques such as fuzzy set theory and neural networks. Bidimensional empirical mode decomposition (BEMD, a new image analysis method recently developed, can potentially be used for pavement crack evaluation. BEMD is an extension of the empirical mode decomposition (EMD, which can decompose nonlinear and nonstationary signals into basis functions called intrinsic mode functions (IMFs. IMFs are monocomponent functions that have well-defined instantaneous frequencies. EMD is a sifting process that is nonparametric and data driven; it does not depend on an a priori basis set. It is able to remove noise from signals without complicated convolution processes. BEMD decomposes an image into two-dimensional IMFs. The present paper explores pavement crack detection using BEMD together with the Sobel edge detector. A number of images are filtered with BEMD to remove noise, and the residual image analyzed with the Sobel edge detector for crack detection. The results are compared with results from the Canny edge detector, which uses a Gaussian filter for image smoothing before performing edge detection. The objective is to qualitatively explore how well BEMD is able to smooth an image for more effective edge detection with the Sobel method.

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

    Science.gov (United States)

    Gray, B.; Skews, B.

    2017-01-01

    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.

  4. 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 s

  5. Wedge wetting by electrolyte solutions

    Science.gov (United States)

    Mußotter, Maximilian; Bier, Markus

    2017-09-01

    The wetting of a charged wedgelike wall by an electrolyte solution is investigated by means of classical density functional theory. As in other studies on wedge wetting, this geometry is considered as the most simple deviation from a planar substrate, and it serves as a first step toward more complex confinements of fluids. By focusing on fluids containing ions and surface charges, features of real systems are covered that are not accessible within the vast majority of previous theoretical studies concentrating on simple fluids in contact with uncharged wedges. In particular, the filling transition of charged wedges is necessarily of first order, because wetting transitions of charged substrates are of first order and the barrier in the effective interface potential persists below the wetting transition of a planar wall; hence, critical filling transitions are not expected to occur for ionic systems. The dependence of the critical opening angle on the surface charge, as well as the dependence of the filling height, of the wedge adsorption, and of the line tension on the opening angle and on the surface charge are analyzed in detail.

  6. A new method for bidimensional analysis of interferometric patterns of liquid films.

    Science.gov (United States)

    Nogueira, Rui; Vazquez, Rosa; Mata, José Luís; Saramago, Benilde

    2005-06-01

    A new method for bidimensional analysis of interferometric patterns of wetting liquid films obtained with the captive bubble technique is described. This method replaces one-dimensional analysis along various intensity profiles with analysis of one average intensity profile. The advantage is to concentrate the surface characteristics of the whole film image into a single intensity profile.

  7. Contact process in a wedge

    CERN Document Server

    Cox, J Theodore; Schinazi, Rinaldo B

    2009-01-01

    We prove that the supercritical one-dimensional contact process survives in certain wedge-like space-time regions, and that when it survives it couples with the unrestricted contact process started from its upper invariant measure. As an application we show that a type of weak coexistence is possible in the nearest-neighbor ``grass-bushes-trees'' successional model introduced in Durrett and Swindle (1991).

  8. Fast and Adaptive Bidimensional Empirical Mode Decomposition Using Order-Statistics Filter Based Envelope Estimation

    Directory of Open Access Journals (Sweden)

    Jesmin F. Khan

    2008-08-01

    Full Text Available A novel approach for bidimensional empirical mode decomposition (BEMD is proposed in this paper. BEMD decomposes an image into multiple hierarchical components known as bidimensional intrinsic mode functions (BIMFs. In each iteration of the process, two-dimensional (2D interpolation is applied to a set of local maxima (minima points to form the upper (lower envelope. But, 2D scattered data interpolation methods cause huge computation time and other artifacts in the decomposition. This paper suggests a simple, but effective, method of envelope estimation that replaces the surface interpolation. In this method, order statistics filters are used to get the upper and lower envelopes, where filter size is derived from the data. Based on the properties of the proposed approach, it is considered as fast and adaptive BEMD (FABEMD. Simulation results demonstrate that FABEMD is not only faster and adaptive, but also outperforms the original BEMD in terms of the quality of the BIMFs.

  9. On the bi-dimensional variational decomposition applied to nonstationary vibration signals for rolling bearing crack detection in coal cutters

    Science.gov (United States)

    Jiang, Yu; Li, Zhixiong; Zhang, Chao; Hu, Chao; Peng, Z.

    2016-06-01

    This work aims to detect rolling bearing cracks using a variational approach. An original method that appropriately incorporates bi-dimensional variational mode decomposition (BVMD) into discriminant diffusion maps (DDM) is proposed to analyze the nonstationary vibration signals recorded from the cracked rolling bearings in coal cutters. The advantage of this variational decomposition based diffusion map (VDDM) method in comparison to the current DDM is that the intrinsic vibration mode of the crack can be filtered into a limited bandwidth in the frequency domain with an estimated central frequency, thus discarding the interference signal components in the vibration signals and significantly improving the crack detection performance. In addition, the VDDM is able to simultaneously process two-channel sensor signals to reduce information leakage. Experimental validation using rolling bearing crack vibration signals demonstrates that the VDDM separated the raw signals into four intrinsic modes, including one roller vibration mode, one roller cage vibration mode, one inner race vibration mode, and one outer race vibration mode. Hence, reliable fault features were extracted from the outer race vibration mode, and satisfactory crack identification performance was achieved. The comparison between the proposed VDDM and existing approaches indicated that the VDDM method was more efficient and reliable for crack detection in coal cutter rolling bearings. As an effective catalyst for rolling bearing crack detection, this newly proposed method is useful for practical applications.

  10. Sobre el buen planteamiento de una ecuación del tipo r-BO bidimensional

    OpenAIRE

    2015-01-01

    En este trabajo tratamos el buen planteamiento en los espacios de Sobolev Hs (R2) del problema de Cauchy asociado a la ecuación del tipo r-BO bidimensional [Fórmula Matemátiva] donde u(x, y, t) es real si x, y, t ∈ R. También, estableceremos resultados sobre la continuación única, para esta ecuación.

  11. Status on bidimensional dark energy parameterizations using SNe Ia JLA and BAO datasets

    CERN Document Server

    Escamilla-Rivera, Celia

    2016-01-01

    Using current observations forecast type Ia supernovae (SNe Ia) Joint Lightcurve Analysis (JLA) binned and baryon acoustic oscillations (BAO), in this paper we investigate six bidimensional dark energy parameterizations in order to explore which has more constraining power. Our results indicate that for Taylor series-like parameterizations at second order in redshift $z$, the tension ($\\sigma$-distance) between these data sets seems to be reduced and their behaviour are $<$1$\\sigma$ compatible with $\\Lambda$CDM.

  12. 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.

  13. 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.

  14. Thermal image filtering by bi-dimensional empirical mode decomposition

    Science.gov (United States)

    Gavriloaia, Bogdan-Mihai; Vizireanu, Constantin-Radu; Fratu, Octavian; Mara, Constantin; Vizireanu, Dragos-Nicolae; Preda, Radu; Gavriloaia, Gheorghe

    2015-02-01

    The abnormal function of cells can be detected by anatomic or physiological registrations. Most of modern approaches, as ultrasound, RMN or CT, show anatomic parametric modifications of tissues or organs. They highlight areas with a larger diameter 1 cm. In the case of skin or superficial cancers, local temperature is different, and it can be put out by thermal imager. Medical imaging is a leading role in modern diagnosis for abnormal or normal tissues or organs. Some information has to be improved for a better diagnosis by reducing or removing some unwanted information like noise affecting image texture. The traditional technologies for medical image enhancement use spatial or frequency domain methods, but whole image processing will hide both partial and specific information for human signals. A particular kind of medical images is represented by thermal imaging. Recently, these images were used for skin or superficial cancers diagnosis, but very clear outlines of certain alleged affected areas need to be shown. Histogram equalization cannot highlights the edges and control the effects of enhancement. A new filtering method was introduced by Huang by using the empirical mode decomposition, EMD. An improved filtering method for thermal images, based on EMD, is presented in this paper, and permits to analyze nonlinear and non-stationary data by the adaptive decomposition into intrinsic mode surfaces. The results, evaluated by SNR ratios, are compared with other filtering methods.

  15. 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.

  16. Hacia un estudio bidimensional del Síndrome de Burnout en estudiantes universitarios

    OpenAIRE

    Yury Rosales Ricardo; Fredy Rafael Rosales Paneque

    2014-01-01

    Se realizó un estudio de revisión con el objetivo proponer una nueva definición del Síndrome de Burnout (SB) en estudiantes universitarios, como un síndrome bidimensional, donde las dos dimensiones imprescindibles o corazón del SB estudiantil son el agotamiento y el desinterés estudiantil. Se elimina la tercera dimensión eficacia o autoeficacia académica en el caso particular de los estudiantes por no cumplir los requisitos situacionales y conceptuales del síndrome en sí.

  17. On Finite Matricial Bidimensional Aspects of a D=4n+2 Simple Field Models

    CERN Document Server

    Colatto, L P; Polito, C M M

    2000-01-01

    We present a finite matricial bi-dimensional structure of the ordinary coordinate frame based on the contraction of the Dirac $\\Gamma $ matrices in Weyl representation to the derivatives in a D=4n+2 spinorial models. Particularly we treat space-times with signatures (2n+1,2n+1) and show two sets of independent matricial coordinates that we analyze as ordinary ones. We apply this formalism to the scalar and spinorial fields. We show that in all cases we have to define a Dirac algebra modified Leibniz rule for the principle of least action. We obtain a matricial holomorphic structure of simple scalar and spinorial matricial fields.

  18. Multiple crack propagation by DBEM in a riveted butt-joint: a simplified bidimensional approach

    Directory of Open Access Journals (Sweden)

    R. Citarella

    2016-03-01

    Full Text Available A Multi-Site Damage (MSD crack growth simulation is presented, carried out by means of Dual Boundary Element Method (DBEM, in a two-dimensional analysis of a cracked butt-joint made of aluminium 2024 T3. An equivalent crack length is proposed for an approximated 2D analysis of a 3D problem where the crack front assumes a part elliptical shape due to secondary bending effects. The assumptions made to perform such simplified bidimensional analyses are validated by comparing numerical results with experimental data, the latter obtained from a fatigue tested riveted butt-joint.

  19. Magneto-transporte em sistemas semicondutores com gas de eletrons bidimensional

    OpenAIRE

    Alvaro Guedes Soares

    1994-01-01

    Resumo: O objetivo básico deste trabalho foi a implantação de técnicas de magneto-transporte em heteroestruturas semicondutoras que apresentam gás de elétron bidimensional (2-DEG), particularmente, o Efeito Shubnikov-de Haas (SdH) e Efeito Hall Quântico (QHE). Neste sentido foi realizada a recuperação de uma bobina supercondutora (criostato e sistema de controle) que permite medidas em campo magnético de até 14 Tesla. Medidas de oscilações Shubnikov-de Haas e Efeito Hall Quântico foram fei...

  20. Numerical Modeling of Two-Dimensional Temperature Dynamics Across Ice-Wedge Polygons

    Science.gov (United States)

    Garayshin, Viacheslav V.

    The ice wedges on the North Slope of Alaska have been forming for many millennia, when the 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. A deeper seasonal thawing may cause melting of ice wedges from their tops. Consequently, the ground starts to settle and a trough begins to form above the ice wedge. The forming trough creates a local temperature anomaly in the surrounding ground, and the permafrost located immediately under the trough starts degrading further. Once the trough is formed, the winter snow cover becomes deeper at the trough area further degrading the permafrost. In this thesis we present a computational approach to study the seasonal temperature dynamics of the ground surrounding an ice wedge and ground subsidence associated with ice wedge degradation. 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 heat conduction and quasi-static mechanical equilibrium 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 temperature, ground displacement and ground 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 employs temperature and moisture content data collected from a field experiment at the Next-Generation Ecosystem Experiments (NGEE) sites in Barrow, Alaska. The model describes seasonal dynamics of temperature and the long-term ground motion near the ice wedges and helps to explain destabilization of the ice wedges north of Alaska's Brooks

  1. 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...... appear to have been commonplace in Flanders during the Late Pleniglacial (Oxygen Isotope Stage 2; OIS2); more specifically, around the Last Glacial Maximum (LGM, similar to 21 kyr ago) and the transition period between the LGM and the start of the Lateglacial (similar to 15 kyr ago). Optical dating...... at one site has revealed two significantly older wedge levels, the younger inset into the older; the younger wedge has an age of 36 +/- 4 kyr (Middle Pleniglacial; OIS3), the older wedge 129 +/- 11 kyr, which points to formation during the Late Saalian (OIS6). Our OSL ages of the wedges and host...

  2. Rainfall induced groundwater mound in wedge-shaped promontories: The Strack-Chernyshov model revisited

    Science.gov (United States)

    Kacimov, A. R.; Kayumov, I. R.; Al-Maktoumi, A.

    2016-11-01

    An analytical solution to the Poisson equation governing Strack's discharge potential (squared thickness of a saturated zone in an unconfined aquifer) is obtained in a wedge-shaped domain with given head boundary conditions on the wedge sides (specified water level in an open water body around a porous promontory). The discharge vector components, maximum elevation of the water table in promontory vertical cross-sections, quantity of groundwater seeping through segments of the wedge sides, the volume of fresh groundwater in the mound are found. For acute angles, the solution to the problem is non-unique and specification of the behaviour at infinity is needed. A "basic" solution is distinguished, which minimizes the water table height above a horizontal bedrock. MODFLOW simulations are carried out in a finite triangular island and compare solutions with a constant-head, no-flow and "basic" boundary condition on one side of the triangle. Far from the tip of an infinite-size promontory one has to be cautious with truncation of the simulated flow domains and imposing corresponding boundary conditions. For a right and obtuse wedge angles, there are no positive solutions for the case of constant accretion on the water table. In a particular case of a confined rigid wedge-shaped aquifer and incompressible fluid, from an explicit solution to the Laplace equation for the hydraulic head with arbitrary time-space varying boundary conditions along the promontory rays, essentially 2-D transient Darcian flows within the wedge are computed. They illustrate that surface water waves on the promontory boundaries can generate strong Darcian waves inside the porous wedge. Evaporation from the water table and sea-water intruded interface (rather than a horizontal bed) are straightforward generalizations for the Poissonian Strack potential.

  3. Antigenos "particulares" a cepas do Trypanosoma cruzi: demonstracao por imunoeletroforese bidimensional Antigens particular to strains of Trypanosoma cruzi: demonstration by bidimensional immunoelectrophoresis

    Directory of Open Access Journals (Sweden)

    Mariza Gonçalves Morgado

    1982-03-01

    Full Text Available Os extratos solúveis das cepas Y, São Felipe e Colombiana do Trypanosoma cruzi foram analisados contra seus antissoros homólogos e heterólogos por imunoeletroforese bidimensional e imunoeletroforese bidimensional com gel intermediário. Os resultados revelaram a existência de pelo menos 35 linhas de precipitação na cepa Y (32 de migração anódica e três de migração catódica, 24 linhas de precipitação anódica na cepa São Felipe e 22 na cepa Colombiana. Estas duas últimas cepas não apresentaram antígenos de migração catódica. Estes antígenos de migração catódica foram considerados "particulares" a cepa Y uma vez que quando testados contra antissoros heterólogos não observamos linhas de precipitação. Através do uso da imunoeletroforese bidimensional com gel intermediário foram evidenciados cinco antígenos particulares à cepa Y quando comparada à São Felipe e oito quando comparada à cepa Colombiana. A cepa São Felipe mostrou um único antígeno particular quando comparada à cepa Colombiana porém, não se evidenciou nenhum antígeno particular quando a cepa São Felipe foi analisada contra o antissoro da cepa Y. A cepa Colombiana não demonstrou nenhum antígeno particular nem quando comparada à cepa Y nem à São Felipe. Nossos resultados revelam que cepas pertencentes a diferentes tipos quanto ao comportamento morfobiológico e histopatológico também demonstram uma acentuada diferença quanto a seus componentes antigênicos.Soluble extracts of Y, São Felipe and Colombian strains of Trypanosoma cruzi were analyzed against their homologous and heterologous antisera by crossed immunoelectrophoresis and crossed immunoelectrophoresis with intermediate gel. In the homologous system, the results showed 35 precipitin lines for Y strain (32 anodic, 3 cathodic, 24 precipitin lines for SãoFelipe strain and 22 for Colombian strain. No cathodic antigen was observed for these last two strains which were consequently

  4. 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.

  5. Benchmarking numerical models of brittle thrust wedges

    NARCIS (Netherlands)

    Buiter, Susanne J H; Schreurs, Guido; Albertz, Markus; Gerya, Taras V.; Kaus, Boris; Landry, Walter; le Pourhiet, Laetitia; Mishin, Yury; Egholm, David L.; Cooke, Michele; Maillot, Bertrand; Thieulot, Cedric|info:eu-repo/dai/nl/270177493; Crook, Tony; May, Dave; Souloumiac, Pauline; Beaumont, Christopher

    2016-01-01

    We report quantitative results from three brittle thrust wedge experiments, comparing numerical results directly with each other and with corresponding analogue results. We first test whether the participating codes reproduce predictions from analytical critical taper theory. Eleven codes pass the

  6. Bidimensional and Multidimensional Principal Component Analysis in Long Term Atmospheric Monitoring

    Directory of Open Access Journals (Sweden)

    Barbara Giussani

    2016-12-01

    Full Text Available Atmospheric monitoring produces huge amounts of data. Univariate and bivariate statistics are widely used to investigate variations in the parameters. To summarize information graphs are usually used in the form of histograms or tendency profiles (e.g., variable concentration vs. time, as well as bidimensional plots where two-variable correlations are considered. However, when dealing with big data sets at least two problems arise: a great quantity of numbers (statistics and graphs are produced, and only two-variable interactions are often considered. The aim of this article is to show how the use of multivariate statistics helps in handling atmospheric data sets. Multivariate modeling considers all the variables simultaneously and returns the main results as bidimensional graphs that are easy-to-read. Principal Component Analysis (PCA; the most known multivariate method and multiway-PCA (Tucker3 are compared from methodological and interpretative points of view. The article demonstrates the ability to emphasize different information depending on the data handling performed. The results and benefits achieved using a more complex model that allows for the simultaneous consideration of the entire variability of the system are compared with the results provided by the simpler but better-known model. Atmospheric monitoring (SO2, NOx, NO2, NO, and O3 data from the Lake Como Area (Italy since 1992 to 2007 were chosen for consideration for the case study.

  7. A fusion algorithm for remote sensing images based on nonsubsampled pyramids and bidimensional empirical decomposition

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In order to improve the quality of remote sensing image fusion,a new method combining nonsubsampled Laplacian pyramid (NLP)and bidimensional empirical mode decomposition(BEMD)is proposed.First,the high resolution panchromatic image (PAN)is decomposed using NLP until the approximate component and the low resolution multispectral image(MS)contain features with a similar scale.Then,the approximation component and the MS are decomposed by BEMD,resulting in a number of bidimensional intrinsic mode functions(BIMF)and a residue respectively.The instantaneous frequency is computed in 4 directions of the BIMFs.Considering the positive or negative coefficients in the corresponding position,a weighted algorithm is designed for fusing the high frequency details using the instantaneous frequency and the coefficient absolute value of the BIMFs as fusion feature.The fused image is then obtained through inverse BEMD and NLP.Experimental results have illustrated the advantage of this method over the IHS,DWT andà-Trous wavelet in both spectral and spatial detail qualities.

  8. SAR image change detection algorithm based on stationary wavelet and bi-dimensional intrinsic mode function

    Science.gov (United States)

    Huang, S. Q.; Wang, Z. L.; Xie, T. G.; Li, Z. C.

    2017-09-01

    Speckle noise in synthetic aperture radar (SAR) image is produced by the coherent imaging mechanism, which brings a great impact on the change information acquisition of multi-temporal SAR images. Two-dimensional stationary wavelet transform (SWT) and bi-dimensional empirical mode decomposition (BEMD) are the non-stationary signal processing theory of multi-scale transform. According to their implementation process and SAR image characteristic, this paper proposed a new multi-temporal SAR image change detection method based on the combination of the stationary wavelet transform and the bi-dimensional intrinsic mode function (BIMF) features, called SWT-BIMF algorithm. The contribution of the new algorithm includes two aspects. One is the design of the two selections of decomposition features, that is, the speckle noise filtering; another is the selected features to perform the enhance processing, so more effective change information will obtain. The feasibility of the SWT-BIMF algorithm is verified by the measured SAR image data, and good experimental results are obtained.

  9. A specially curved wedge for eliminating wedge angle effect in unsteady shock reflection

    Science.gov (United States)

    Wang, He; Zhai, Zhigang; Luo, Xisheng; Yang, Jiming; Lu, Xiyun

    2017-08-01

    A curved wedge with a specific shape is designed and manufactured to guarantee the wedge angle unvaried during the cylindrically converging shock moving along the wedge. Thus the variation of the wedge angle caused by the wedge will be eliminated in unsteady shock reflection. Different initial wedge angles are considered to observe regular reflection and Mach reflection. When Mach reflection occurs, it is found that direct Mach reflection is persisted over the wedge without wave pattern transitions, which differs from our previous work with varied wedge angles [Zhang et al. "Reflection of cylindrical converging shock wave over a plane wedge," Phys. Fluids 28, 086101 (2016)]. Moreover, the Mach stem is nearly straight when the wedge angle is relatively large, and the trajectory of triple point can be well predicted by three-shock theory. It is believed that the straight Mach stem results from the coupling effect of the converging shock and the convexly curved wedge, which exert opposite effects on the Mach stem curvature. As the wedge angle reduces, the three-shock theory prediction deviates from the present results owing to the curved Mach stem. Stronger vortices are produced near the wall, which are caused by the interaction of two shear layers, and whether the stronger vortices will be generated near the wall depends on the reflection number of the shock wave over the tube wall and wedge. The length of disturbed shock front in the Mach reflection is found to increase nonlinearly due to the unsteady feature of the flow. The growth rate of length reduces as the shock converges because of the geometrical contraction effect. Further the lengths of the Mach stem and the disturbed shock front are compared, and the results show that although the difference exists between them, both of them show a similar variation tendency. Compared with our previous work with varied wedge angles, the variation of the wedge angle has great effects on the Mach stem length and wave

  10. Mantle wedge dynamics from seismic anisotropy (Invited)

    Science.gov (United States)

    Long, M. D.; Wirth, E. A.

    2013-12-01

    The mantle wedge above subducting slabs plays a critical role in many of the physical processes associated with subduction, including water transport into the upper mantle and the generation and transport of melts. Our understanding of mantle wedge dynamics is incomplete; in particular, the mantle flow field above subducting slabs remains poorly understood. Because seismic anisotropy is a consequence of deformation, observations of anisotropy (such as shear wave splitting and P-to-SH converted waves) can constrain the geometry of the wedge flow field. Additionally, because the presence of water (either in nominally anhydrous minerals or as hydrous phases) can have a large effect on anisotropic structure, a detailed understanding of mantle wedge anisotropy can help to constrain processes related to water cycling in subduction systems. We present a global, synoptic view of anisotropy observations in subduction zone mantle wedges, compiled from a large number of individual studies, with the goal of understanding the first-order controls on wedge anisotropy and flow patterns. This compilation allows us to explicitly test the predictions made by many different conceptual models for wedge anisotropy, as well as to explore the relationships between observed anisotropy parameters and other parameters that describe subduction. We find that no simple model can explain all of the trends observed in the global data set. Mantle wedge flow is likely controlled by a combination of downdip motion of the slab, trench migration, ambient mantle flow, small-scale convection, proximity to slab edges, and slab morphology, with the relative contributions of these in any given subduction system controlled by the subduction kinematics and mantle rheology. There is also a likely contribution from B-type olivine and/or serpentinite fabric in many subduction zones, governed by the local thermal structure and volatile distribution.

  11. Long-range hybrid wedge plasmonic waveguide.

    Science.gov (United States)

    Zhang, Zhonglai; Wang, Jian

    2014-11-03

    We design a novel long-range hybrid wedge plasmonic (LRHWP) waveguide composed of two identical dielectric nanowires symmetrically placed on two opposed wedges of a diamond shaped metal wire. With strong coupling between the dielectric nanowire mode and long-range surface plasmon polariton (SPP) mode, both deep subwavelength mode confinement and low propagation loss are achieved. On one hand, when compared to the previous long-range hybrid SPP waveguide, LRHWP waveguide can achieve smaller mode size with similar propagation length; on the other hand, when compared to the previous hybrid wedge SPP waveguide, LRHWP waveguide can provide an order of magnitude longer propagation length with similar level of mode confinement. The designed LRHWP waveguide also features an overall advantage of one-order improvement of Figure of Merit. We further evaluate in detail the impacts of possible practical fabrication imperfections on the mode properties. The obtained results of mode properties show that the proposed LRHWP waveguide with an optimized wedge tip angle of 140 degree is fairly tolerant to practical fabrication errors in geometry parameters such as misalignment in the horizontal direction, asymmetry in the vertical direction, variation of wedge tip angle, tilt or rotation of metal wire, and variation of wedge tip curvature radius.

  12. 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.

  13. 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.

  14. Wedged tibial components for total knee arthroplasty.

    Science.gov (United States)

    Jeffery, R S; Orton, M A; Denham, R A

    1994-08-01

    Severe coronal deformity of the knee is frequently associated with erosion of one tibial condyle. This can cause problems with fixation and alignment during total knee arthroplasty. If the tibia is cut to the level of the more worn side, valuable bone is sacrificed; if the less worn side is chosen, the deficiency must be filled with bone--graft, cement, or a prosthesis. Tibial components with an integral polyethylene wedge on the undersurface were introduced in 1980 for use in patients with a bony deficit on one tibial condyle. The authors believe that the Denham prosthesis (Biomet, Wales, U.K.) was the first knee arthroplasty to offer such spacers. Twenty-six patients with preoperative varus deformity in whom a wedged component was used were compared with 29 historic control subjects. None of the wedged components loosened after a median follow-up period of 8 years compared with loosening in five of the control subjects (P = .01). In three of the control subjects a fractured triangle of cement was present on the radiographs. Use of the wedges was not accompanied by an improvement in postoperative alignment. The authors conclude that the wedges resulted in improved fixation that was independent of postoperative alignment.

  15. Long polymers near wedges and cones

    Science.gov (United States)

    Hammer, Yosi; Kantor, Yacov

    2015-12-01

    We perform a Monte Carlo study of N -step self-avoiding walks, attached to the corner of an impenetrable wedge in two dimensions (d =2 ), or the tip of an impenetrable cone in d =3 , of sizes ranging up to N =106 steps. We find that the critical exponent γα, which determines the dependence of the number of available conformations on N for a cone or wedge with opening angle α , is in good agreement with the theory for d =2 . We study the end-point distribution of the walks in the allowed space and find similarities to the known behavior of random walks (ideal polymers) in the same geometry. For example, the ratio between the mean square end-to-end distances of a polymer near the cone or wedge and a polymer in free space depends linearly on γα, as is known for ideal polymers. We show that the end-point distribution of polymers attached to a wedge does not separate into a product of angular and radial functions, as it does for ideal polymers in the same geometry. The angular dependence of the end position of polymers near the wedge differs from theoretical predictions.

  16. Distribución y corte de piezas irregulares con anidamiento bidimensional en la industria minera

    Directory of Open Access Journals (Sweden)

    José Arzola-Ruíz

    2010-03-01

    Full Text Available La necesidad del ahorro de material durante el corte de piezas en chapas ha provocado el desarrollo de procedimientos y técnicas de optimización, con la ayuda de las nuevas tecnologías de la informática y las comunicaciones. A pesar de la existencia de diversas plataformas automatizadas para la generación de distribuciones y rutas de corte, el ahorro de material constituye un indicador de permanente atención en la industria minera. En el presente trabajo se ilustra el estado actual del desarrollo de las técnicas de distribución y corte de piezas en chapas y se define la concepción de un procedimiento para la distribución de piezas irregulares con anidamiento bidimensional.

  17. Bidimensional nano-optomechanics and topological backaction in a non-conservative radiation force field

    CERN Document Server

    Gloppe, Arnaud; Dupont-Ferrier, Eva; Siria, Alessandro; Poncharal, Philippe; Bachelier, Guillaume; Vincent, Pascal; Arcizet, Olivier

    2014-01-01

    Optomechanics, which explores the fundamental coupling between light and mechanical motion, has made important advances in both exploring and manipulating macroscopic mechanical oscillators down to the quantum level. However, dynamical effects related to the vectorial nature of the optomechanical interaction remain to be investigated. Here we study a nanowire with sub-wavelength dimensions strongly coupled to a tightly focused beam of light, enabling ultrasensitive readout of the nanoresonators dynamics. We experimentally determine the vectorial structure of the optomechanical interaction and demonstrate that bidimensional dynamical backaction governs the nanowire dynamics. Moreover, the non-conservative topology of the optomechanical interaction is responsible for a novel canonical signature of strong coupling between the nanoresonator mechanical modes, leading to a topological instability. These results have a universal character and illustrate the increased sensitivity of nanomechanical devices towards top...

  18. Bidimensional nano-optomechanics and topological backaction in a non-conservative radiation force field.

    Science.gov (United States)

    Gloppe, A; Verlot, P; Dupont-Ferrier, E; Siria, A; Poncharal, P; Bachelier, G; Vincent, P; Arcizet, O

    2014-11-01

    Optomechanics, which explores the fundamental coupling between light and mechanical motion, has made important advances in manipulating macroscopic mechanical oscillators down to the quantum level. However, dynamical effects related to the vectorial nature of the optomechanical interaction remain to be investigated. Here we study a nanowire with subwavelength dimensions coupled strongly to a tightly focused beam of light, enabling an ultrasensitive readout of the nanoresonator dynamics. We determine experimentally the vectorial structure of the optomechanical interaction and demonstrate that a bidimensional dynamical backaction governs the nanowire dynamics. Moreover, the spatial topology of the optomechanical interaction is responsible for novel canonical signatures of strong coupling between mechanical modes, which leads to a topological instability that underlies the non-conservative nature of the optomechanical interaction. These results have a universal character and illustrate the increased sensitivity of nanomechanical devices towards spatially varying interactions, opening fundamental perspectives in nanomechanics, optomechanics, ultrasensitive scanning force microscopy and nano-optics.

  19. Effects of directional and neutral category labels in bidimensional rule-learning problems.

    Science.gov (United States)

    Neumann, P G

    1974-07-01

    In bidimensional concept problems, the distinction between primary and complementary rule forms is, in some sense, a function of the directional nature of the sorting category labels. Primary rules are those rules which assign the TT class to the "positive" category. Complementary rule forms are obtained by reversing these category assignments. Instead of directional labels, neutral labels can be used. Reversing these labels creates no fundamental change in the solution of the problem. The present experiment investigates the effect of directional and neutral category labels in a design which incorporates all 12 problems defined by the combination of directional and neutral labels. Significant effects of labels on performance were obtained. Implications of these effects for hypotheses advanced by Seggie (1969), Peters and Denny (1971), and Bourne and Guy (1968) are discussed.

  20. 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%.

  1. Structure of turbulent wedges created by isolated surface roughness

    Science.gov (United States)

    Kuester, Matthew S.; White, Edward B.

    2016-04-01

    Isolated surface roughness in a laminar boundary layer can create a wedge of turbulence that spreads laterally into the surrounding laminar flow. Some recent studies have identified high- and low-speed streaks along the exterior of turbulent wedges. In this experiment, developing turbulent wedges are measured to observe the creation of these streaks. Naphthalene shear stress surface visualization and hotwire measurements are utilized to investigate the details of turbulent wedges created by cylinders in a laminar flat-plate boundary layer. Both the surface visualization and the hotwire measurements show high- and low-speed streaks in the wake of the cylinder that devolve into a turbulent wedge. The turbulent wedge spreading is associated with the emergence of these high- and low-speed streaks along the outside of the wedge. As the wedge evolves in the streamwise direction, these streaks persist inside of the core of the wedge, while new, lower amplitude streaks form along the outside of the wedge. Adding asymmetry to the cylinder moved the virtual origin closer to the roughness and increased the vortex shedding frequency, while adding small-scale roughness features did not strongly affect turbulent wedge development. Intermittency calculations additionally show the origin of the turbulent core inside of the wedge. The structure and spacing of the high-speed streaks along the extremities of the turbulent wedge give insight into the spreading angle of the turbulent wedge.

  2. Simulation of water entry of an elastic wedge using the FDS scheme and HCIB method

    Institute of Scientific and Technical Information of China (English)

    SHIN Sangmook; BAE Sung Yong

    2013-01-01

    The hydroelasticity of water entry of an elastic wedge is simulated using a code developed using the flux-difference splitting scheme for immiscible and incompressible fluids and the hybrid Cartesian/immersed boundary method.The free surface is regarded as a moving contact discontinuity and is captured without any additional treatment along the interface.Immersed boundary nodes are distributed inside a fluid domain based on the edges that cross an instantaneous body boundary.Dependent variables are reconstructed at each immersed boundary node with the help of an interpolation along a local normal line for providing a boundary condition for a discretized flow problem.A dynamic beam equation is used for modeling the elastic deformation of a wedge.The developed code is validated through comparisons with other experimental and computational results for a free-falling wedge.The effects of the elastic deformation of the wedge on the pressure fields and time histories of the impact force are investigated in relation to the stiffness and density of the structure.Grid independence test is carried out for the computed time history of the force acting on an elastic wedge.

  3. Explicit reconstruction of the entanglement wedge

    CERN Document Server

    Kim, Jung-Wook

    2016-01-01

    The problem of bulk locality, or how the boundary encodes the bulk in AdS/CFT, is still a subject of study today. One of the major issues that needs more elucidation is the problem of subregion duality; what information of the bulk a given boundary subregion encodes. Although proofs given by two teams of researchers, Dong, Harlow, and Wall and Bao, and Kim, state that the entanglement wedge of the bulk should be reconstructible from boudnary subregions, no explicit procedure for reconstructing the entanglement wedge was as of yet given. In this paper, mode sum approach to obtaining smearing functions is generalised to include bulk reconstruction in the entanglement wedge of boundary subregions. It is generally expectated that solutions to the wave equation on a complicated coordinate patch are needed, but this hard problem has been transferred to a less hard but tractable problem of matrix inversion.

  4. Non-Newtonian viscosity wedge in film formation of EHL

    Institute of Scientific and Technical Information of China (English)

    GUOF.; WONGP.L.

    2001-01-01

    This paper aims to evaluate the action of viscosity wedge in the oil film formation ofEHL at opposite sliding and zero entrainment. Using solvers developed for Newtonian and Eyringfluids, the film formation behavior originating from viscosity wedge is investigated. The numericalsimulation displays that lubricant film formation induced by viscosity wedge is different from that bythe well-known geometrical wedge with entrainment in classic EHL. The numerical analyses showthat at high opposite sliding speed the viscosity wedge acts as a leading role in film formation, thenon-Newtonian effects can have a pronounced influence on action of the viscosity wedge.

  5. A review of dynamics modelling of friction wedge suspensions

    Science.gov (United States)

    Wu, Qing; Cole, Colin; Spiryagin, Maksym; Sun, Yan Quan

    2014-11-01

    Three-piece bogies with friction wedge suspensions are the most widely used bogies in heavy haul trains. Fiction wedge suspensions play a key role in these wagon systems. This article reviews current techniques in dynamic modelling of friction wedge suspension with various motivations: to improve dynamic models of friction wedge suspensions so as to improve general wagon dynamics simulations; to seek better friction wedge suspension models for wagon stability assessments in complex train systems; to improve the modelling of other friction devices, such as friction draft gear. Relevant theories and friction wedge suspension models developed by using commercial simulation packages and in-house simulation packages are reviewed.

  6. 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 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...... 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...

  7. Wedge filling and interface delocalization in finite Ising lattices with antisymmetric surface fields

    Science.gov (United States)

    Milchev, Andrey; Müller, M.; Binder, K.; Landau, D. P.

    2003-09-01

    Theoretical predictions by Parry et al. for wetting phenomena in a wedge geometry are tested by Monte Carlo simulations. Simple cubic L×L×Ly Ising lattices with nearest neighbor ferromagnetic exchange and four free L×Ly surfaces, at which antisymmetric surface fields ±Hs act, are studied for a wide range of linear dimensions (4⩽L⩽320, 30⩽Ly⩽1000), in an attempt to clarify finite size effects on the wedge filling transition in this “double-wedge” geometry. Interpreting the Ising model as a lattice gas, the problem is equivalent to a liquid-gas transition in a pore with quadratic cross section, where two walls favor the liquid and the other two walls favor the gas. For temperatures T below the bulk critical temperature Tc this boundary condition (where periodic boundary conditions are used in the y direction along the wedges) leads to the formation of two domains with oppositely oriented magnetization and separated by an interface. For L,Ly→∞ and T larger than the filling transition temperature Tf(Hs), this interface runs from the one wedge where the surface planes with a different sign of the surface field meet (on average) straight to the opposite wedge, so that the average magnetization of the system is zero. For Tinterface is bound either to the wedge where the two surfaces with field -Hs meet (then the total magnetization m of the system is positive) or to the opposite wedge (then minterface midpoint from the wedges is studied as T→Tf(Hs) from below, as is the corresponding behavior of the magnetization and its moments. We consider the variation of l0 for T>Tf(Hs) as a function of a bulk field and find that the associated exponents agree with theoretical predictions. The correlation length ξy in the y direction along the wedges is also studied, and we find no transition for finite L and Ly→∞. For L→∞ the prediction l0∝(Hsc-Hs)-1/4 is verified, where Hsc(T) is the inverse function of Tf(Hs) and ξy∝(Hsc-Hs)-3/4, respectively. We

  8. Benchmarking numerical models of brittle thrust wedges

    NARCIS (Netherlands)

    Buiter, Susanne J H; Schreurs, Guido; Albertz, Markus; Gerya, Taras V.; Kaus, Boris; Landry, Walter; le Pourhiet, Laetitia; Mishin, Yury; Egholm, David L.; Cooke, Michele; Maillot, Bertrand; Thieulot, Cedric; Crook, Tony; May, Dave; Souloumiac, Pauline; Beaumont, Christopher

    2016-01-01

    We report quantitative results from three brittle thrust wedge experiments, comparing numerical results directly with each other and with corresponding analogue results. We first test whether the participating codes reproduce predictions from analytical critical taper theory. Eleven codes pass the s

  9. PARADOX SOLUTION ON ELASTIC WEDGE DISSIMILAR MATERIALS

    Institute of Scientific and Technical Information of China (English)

    姚伟岸; 张兵茹

    2003-01-01

    According to the Hellinger-Reissner variational principle and introducing proper transformation of variables, the problem on elastic wedge dissimilar materials can be led to Hamiltonian system, so the solution of the problem can be got by employing the separation of variables method and symplectic eigenfunction expansion under symplectic space, which consists of original variables and their dual variables. The eigenvalue - 1 is a special one of all symplectic eigenvalue for Hamiltonian system in polar coordinate. In general, the eigenvalue - is a single eigenvalue, and the classical solution of an elastic wedge dissimilar materials subjected to a unit concentrated couple at the vertex is got directly by solving the eigenfunction vector for eigenvalue - 1 . But the eigenvalue - 1 becomes a double eigenvalue when the vertex angles and modulus of the materials satisfy certain definite relationships and the classical solution for the stress distribution becomes infinite at this moment, that is, the paradox should occur. Here the Jordan form eigenfunction vector for eigenvalue - 1 exists, and solution of the paradox on elastic wedge dissimilar materials subjected to a unit concentrated couple at the vertex is obtained directly by solving this special Jordan form eigenfunction. The result shows again that the solutions of the special paradox on elastic wedge in the classical theory of elasticity are just Jordan form solutions in symplectic space under Hamiltonian system.

  10. Radiotherapy treatment planning with dynamic wedges--an algorithm for generating wedge factors and beam data.

    Science.gov (United States)

    Thomas, S J; Foster, K R

    1995-09-01

    If the jaws of a linear accelerator are moved under computer control during irradiation, dose distributions similar to those with wedge filters can be produced. Varian linear accelerators utilize this effect to give a 'dynamic wedge', using segmented treatment tables (STTs). An algorithm is described to generate the dose per monitor unit at any point in a beam, using the STT values. Dynamically wedged beams are modelled as the superposition of static asymmetric beams, using an algorithm based on beam data measured for symmetric beams. Predictions of wedge factors, depth doses and profiles generated using the algorithm are compared with measurements. Good agreement is found between predictions and measurements. The calculation time is typically 5 ms/dose point on a PC with a 486DX processor.

  11. 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

    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......The purpose of this work is to numerically investigate the accuracy of the standard impedance boundary condition (SIBC) approximation for edge diffraction. To this end, we compare the scattering by coated wedges and SIBC wedges for which the diffracted field from a single edge can be observed...... 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...

  12. Benchmarking numerical models of brittle thrust wedges

    Science.gov (United States)

    Buiter, Susanne J. H.; Schreurs, Guido; Albertz, Markus; Gerya, Taras V.; Kaus, Boris; Landry, Walter; le Pourhiet, Laetitia; Mishin, Yury; Egholm, David L.; Cooke, Michele; Maillot, Bertrand; Thieulot, Cedric; Crook, Tony; May, Dave; Souloumiac, Pauline; Beaumont, Christopher

    2016-11-01

    We report quantitative results from three brittle thrust wedge experiments, comparing numerical results directly with each other and with corresponding analogue results. We first test whether the participating codes reproduce predictions from analytical critical taper theory. Eleven codes pass the stable wedge test, showing negligible internal deformation and maintaining the initial surface slope upon horizontal translation over a frictional interface. Eight codes participated in the unstable wedge test that examines the evolution of a wedge by thrust formation from a subcritical state to the critical taper geometry. The critical taper is recovered, but the models show two deformation modes characterised by either mainly forward dipping thrusts or a series of thrust pop-ups. We speculate that the two modes are caused by differences in effective basal boundary friction related to different algorithms for modelling boundary friction. The third experiment examines stacking of forward thrusts that are translated upward along a backward thrust. The results of the seven codes that run this experiment show variability in deformation style, number of thrusts, thrust dip angles and surface slope. Overall, our experiments show that numerical models run with different numerical techniques can successfully simulate laboratory brittle thrust wedge models at the cm-scale. In more detail, however, we find that it is challenging to reproduce sandbox-type setups numerically, because of frictional boundary conditions and velocity discontinuities. We recommend that future numerical-analogue comparisons use simple boundary conditions and that the numerical Earth Science community defines a plasticity test to resolve the variability in model shear zones.

  13. Acceptance Threshold: A Bidimensional Research Method for User-Oriented Quality Evaluation Studies

    Directory of Open Access Journals (Sweden)

    S. Jumisko-Pyykkö

    2008-01-01

    Full Text Available Subjective quality evaluation is widely used to optimize system performance as a part of end-products. It is often desirable to know whether a certain system performance is acceptable, that is, whether the system reaches the minimum level to satisfy user expectations and needs. The goal of this paper is to examine research methods for assessing overall acceptance of quality in subjective quality evaluation methods. We conducted three experiments to develop our methodology and test its validity under heterogeneous stimuli in the context of mobile television. The first experiment examined the possibilities of using a simplified continuous assessment method for assessing overall acceptability. The second experiment explored the boundary between acceptable and unacceptable quality when the stimuli had clearly detectable differences. The third experiment compared the perceived quality impacts of small differences between the stimuli close to the threshold of acceptability. On the basis of our results, we recommend using a bidimensional retrospective measure combining acceptance and satisfaction in consumer-/user-oriented quality evaluation experiments.

  14. Locus of Control revisited: development of a new bi-dimensional measure

    Directory of Open Access Journals (Sweden)

    Javier Suárez-Álvarez

    Full Text Available Locus of control (LOC has a long tradition in Psychology, and various instruments have been designed for its measurement. However, the dimensionality of the construct is unclear, and still gives rise to considerable controversy. The aim of the present work is to present new evidence of validity in relation to the dimensionality of LOC. To this end, we developed a new measurement instrument with 23 items. The sample was made up of 697 Spanish participants, of whom 57.5% were women (M=22.43; SD= 9.19. The results support the bi-dimensionality of LOC: internal (α=.87 and external (α=.85. Furthermore, both subscales have shown adequate validity evidence in relation to self-efficacy, achievement motivation and optimism (r xy> .21. Statistically significant differences were found by sex (p < .05: men scored higher in external LOC and women in internal LOC. The validity evidence supports a two-dimensional structure for the LOC, and the measurement instrument developed showed adequate psychometric properties.

  15. A Bidimensional Empirical Mode Decomposition Method for Fusion of Multispectral and Panchromatic Remote Sensing Images

    Directory of Open Access Journals (Sweden)

    Weihua Dong

    2014-09-01

    Full Text Available This article focuses on the image fusion of high-resolution panchromatic and multispectral images. We propose a new image fusion method based on a Hue-Saturation-Value (HSV color space model and bidimensional empirical mode decomposition (BEMD, by integrating high-frequency component of panchromatic image into multispectral image and optimizing the BEMD in decreasing sifting time, simplifying extrema point locating and more efficient interpolation. This new method has been tested with a panchromatic image (SPOT, 10-m resolution and a multispectral image (TM, 28-m resolution. Visual and quantitative assessment methods are applied to evaluate the quality of the fused images. The experimental results show that the proposed method provided superior performance over conventional fusion algorithms in improving the quality of the fused images in terms of visual effectiveness, standard deviation, correlation coefficient, bias index and degree of distortion. Both five different land cover types WorldView-II images and three different sensor combinations (TM/SPOT, WorldView-II, 0.5 m/1 m resolution and IKONOS, 1 m/4 m resolution validated the robustness of BEMD fusion performance. Both of these results prove the capability of the proposed BEMD method as a robust image fusion method to prevent color distortion and enhance image detail.

  16. Enhancing Image Denoising Performance of Bidimensional Empirical Mode Decomposition by Improving the Edge Effect

    Directory of Open Access Journals (Sweden)

    Feng-Ping An

    2015-01-01

    Full Text Available Bidimensional empirical mode decomposition (BEMD algorithm, with high adaptive ability, provides a suitable tool for the noisy image processing, and, however, the edge effect involved in its operation gives rise to a problem—how to obtain reliable decomposition results to effectively remove noises from the image. Accordingly, we propose an approach to deal with the edge effect caused by BEMD in the decomposition of an image signal and then to enhance its denoising performance. This approach includes two steps, in which the first one is an extrapolation operation through the regression model constructed by the support vector machine (SVM method with high generalization ability, based on the information of the original signal, and the second is an expansion by the closed-end mirror expansion technique with respect to the extrema nearest to and beyond the edge of the data resulting from the first operation. Applications to remove the Gaussian white noise, salt and pepper noise, and random noise from the noisy images show that the edge effect of the BEMD can be improved effectively by the proposed approach to meet requirement of the reliable decomposition results. They also illustrate a good denoising effect of the BEMD by improving the edge effect on the basis of the proposed approach. Additionally, the denoised image preserves information details sufficiently and also enlarges the peak signal-to-noise ratio.

  17. Uma forma bidimensional que maximiza a resist\\^encia aerodin\\^amica newtoniana

    CERN Document Server

    Gouveia, Paulo D F; Torres, Delfim F M

    2007-01-01

    (English) In a previous work [Nonlinearity, 20:2271-2287, 2007; arXiv:math/0703895] it is investigated, by means of computational simulations, shapes of nonconvex bodies that maximize resistance to its motion on a rarefied medium, considering that bodies are moving forward and at the same time slowly rotating. Here the previous results are improved: we obtain a two-dimensional geometric shape that confers to the body a resistance very close to the supremum value (R=1.4965<1.5). ----- Resumo (Portuguese) Um corpo bidimensional, apresentando um ligeiro movimento rotacional, desloca-se num meio rarefeito de part\\'iculas que colidem com ele de uma forma perfeitamente el\\'astica. Em investiga\\c{c}\\~oes que os dois primeiros autores realizaram anteriormente [Nonlinearity, 20:2271-2287, 2007; arXiv:math/0703895], procuraram-se formas de corpos que maximizassem a for\\c{c}a de travagem do meio ao seu movimento. Dando continuidade a esse estudo, encetam-se agora novas investiga\\c{c}\\~oes que culminam num resultado q...

  18. Chemical beam epitaxy of pseudomorphic InGaAs/InP bidimensional electron gas

    Energy Technology Data Exchange (ETDEWEB)

    Carlin, J.F.; Rudra, A.; Ilegems, M. [Ecole Polytechnique Federale de Lausanne (Switzerland). Inst. de Micro- et Optoelectronique

    1996-12-31

    The authors have optimized the growth of InGaAs/InP bidimensional electron gas layers with a compressively strained channel. The highest 2DEG mobility, {micro} = 118,000 cm{sup 2}V{sup {minus}1}s{sup {minus}1} with n{sub s} = 1.4 10{sup 12}cm{sup {minus}2} at 77K, is obtained with a 80% In content channel, the growth temperature being 480 C and with a V/III ratio of 4. The transport properties appear to be limited by different phenomena, depending on the growth parameters: (1) appearance of elongated defects or In droplets at higher Tg and/or lower V/III ratio; (2) grainy roughness at lower Tg and/or higher V/III ratio; and (3) electrically active defects for Tg below 480 C. The insertion of Ga{sub 0.1}In{sub 0.9}P barriers brings a measurable improvement by lowering the sheet resistance by about 20%, but no strain compensation effect can be evidenced.

  19. Life at the wedge: the activity and diversity of arctic ice wedge microbial communities.

    Science.gov (United States)

    Wilhelm, Roland C; Radtke, Kristin J; Mykytczuk, Nadia C S; Greer, Charles W; Whyte, Lyle G

    2012-04-01

    The discovery of polygonal terrain on Mars underlain by ice heightens interest in the possibility that this water-bearing habitat may be, or may have been, a suitable habitat for extant life. The possibility is supported by the recurring detection of terrestrial microorganisms in subsurface ice environments, such as ice wedges found beneath tundra polygon features. A characterization of the microbial community of ice wedges from the high Arctic was performed to determine whether this ice environment can sustain actively respiring microorganisms and to assess the ecology of this extreme niche. We found that ice wedge samples contained a relatively abundant number of culturable cells compared to other ice habitats (∼10(5) CFU·mL(-1)). Respiration assays in which radio-labeled acetate and in situ measurement of CO(2) flux were used suggested low levels of microbial activity, though more sensitive techniques are required to confirm these findings. Based on 16S rRNA gene pyrosequencing, bacterial and archaeal ice wedge communities appeared to reflect surrounding soil communities. Two Pseudomonas sp. were the most abundant taxa in the ice wedge bacterial library (∼50%), while taxa related to ammonia-oxidizing Thaumarchaeota occupied 90% of the archaeal library. The tolerance of a variety of isolates to salinity and temperature revealed characteristics of a psychrotolerant, halotolerant community. Our findings support the hypothesis that ice wedges are capable of sustaining a diverse, plausibly active microbial community. As such, ice wedges, compared to other forms of less habitable ground ice, could serve as a reservoir for life on permanently cold, water-scarce, ice-rich extraterrestrial bodies and are therefore of interest to astrobiologists and ecologists alike. .

  20. Wedge filling and interface delocalization in finite Ising lattices with antisymmetric surface fields.

    Science.gov (United States)

    Milchev, Andrey; Müller, M; Binder, K; Landau, D P

    2003-09-01

    Theoretical predictions by Parry et al. for wetting phenomena in a wedge geometry are tested by Monte Carlo simulations. Simple cubic LxLxL(y) Ising lattices with nearest neighbor ferromagnetic exchange and four free LxL(y) surfaces, at which antisymmetric surface fields +/-H(s) act, are studied for a wide range of linear dimensions (4Ising model as a lattice gas, the problem is equivalent to a liquid-gas transition in a pore with quadratic cross section, where two walls favor the liquid and the other two walls favor the gas. For temperatures T below the bulk critical temperature T(c) this boundary condition (where periodic boundary conditions are used in the y direction along the wedges) leads to the formation of two domains with oppositely oriented magnetization and separated by an interface. For L,L(y)--> infinity and T larger than the filling transition temperature T(f)(H(s)), this interface runs from the one wedge where the surface planes with a different sign of the surface field meet (on average) straight to the opposite wedge, so that the average magnetization of the system is zero. For Tinterface is bound either to the wedge where the two surfaces with field -H(s) meet (then the total magnetization m of the system is positive) or to the opposite wedge (then minterface midpoint from the wedges is studied as T-->T(f)(H(s)) from below, as is the corresponding behavior of the magnetization and its moments. We consider the variation of l(0) for T>T(f)(H(s)) as a function of a bulk field and find that the associated exponents agree with theoretical predictions. The correlation length xi(y) in the y direction along the wedges is also studied, and we find no transition for finite L and L(y)--> infinity. For L--> infinity the prediction l(0) proportional, variant (H(sc)-H(s))(-1/4) is verified, where H(sc)(T) is the inverse function of T(f)(H(s)) and xi(y) proportional, variant (H(sc)-H(s))(-3/4), respectively. We also find that m vanishes discontinuously at the

  1. Radiation pressure on a dielectric wedge

    CERN Document Server

    Mansuripur, Masud; Moloney, Jerome V

    2014-01-01

    The force of electromagnetic radiation on a dielectric medium may be derived by a direct application of the Lorentz law of classical electrodynamics. While the light's electric field acts upon the (induced) bound charges in the medium, its magnetic field exerts a force on the bound currents. We use the example of a wedge-shaped solid dielectric, immersed in a transparent liquid and illuminated at Brewster's angle, to demonstrate that the linear momentum of the electromagnetic field within dielectrics has neither the Minkowski nor the Abraham form; rather, the correct expression for momentum density has equal contributions from both. The time rate of change of the incident momentum thus expressed is equal to the force exerted on the wedge plus that experienced by the surrounding liquid.

  2. Graphene Plasmons in Triangular Wedges and Grooves

    CERN Document Server

    Gonçalves, P A D; Xiao, Sanshui; Vasilevskiy, M I; Mortensen, N Asger; Peres, N M R

    2016-01-01

    The ability to effectively guide electromagnetic radiation below the diffraction limit is of the utmost importance in the prospect of all-optical plasmonic circuitry. Here, we propose an alternative solution to conventional metal-based plasmonics by exploiting the deep subwavelength confinement 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 plasmons counterparts, but now scaled by a (purely) geometric factor in which all the information about the system's geometry is contained. We believe our results pave the way for the development of novel custom-tailored photonic devices for subwavelength waveg...

  3. Checking the virtual treatment modality Wedge from Siemens; Verificacion de la modalidad de tratamiento virtual WEDGE de SIEMENS

    Energy Technology Data Exchange (ETDEWEB)

    Suero Rodrigo, M. A.; Marques Fraguela, E.

    2011-07-01

    The treatment modality Virtual Wedge (VW) or implemented by Siemens virtual wedge in electron linear accelerators achieved dose distributions are similar but not identical, to those obtained with physical wedges. Among the advantages against the latter is the greater ease of use, wedge factor close to one, and lower peripheral dose. However, these benefits are to be effective requires a through quality control dependence because a larger number of parameters that control the generation of the beam, the dose monitor system and the movement of the jaws of the collimator. We performed a study of the wedge taking into account different configurations that can affect their behavior from the dosimetric point of view.

  4. Mantle flow in subduction systems: The mantle wedge flow field and implications for wedge processes

    Science.gov (United States)

    Long, Maureen D.; Wirth, Erin A.

    2013-02-01

    The mantle wedge above subducting slabs is associated with many important processes, including the transport of melt and volatiles. Our understanding of mantle wedge dynamics is incomplete, as the mantle flow field above subducting slabs remains poorly understood. Because seismic anisotropy is a consequence of deformation, measurements of shear wave splitting can constrain the geometry of mantle flow. In order to identify processes that make first-order contributions to the pattern of wedge flow, we have compiled a data set of local S splitting measurements from mantle wedges worldwide. There is a large amount of variability in splitting parameters, with average delay times ranging from ~0.1 to 0.3 s up to ~1.0-1.5 s and large variations in fast directions. We tested for relationships between splitting parameters and a variety of parameters related to subduction processes. We also explicitly tested the predictions made by 10 different models that have been proposed to explain splitting patterns in the mantle wedge. We find that no simple model can explain all of the trends observed in the global data set. Mantle wedge flow is likely controlled by a combination of downdip motion of the slab, trench migration, ambient mantle flow, small-scale convection, proximity to slab edges, and slab morphology, with the relative contributions of these in any given subduction system controlled by the subduction kinematics and mantle rheology. There is also a likely contribution from B-type olivine and/or serpentinite fabric in many subduction zones, governed by the local thermal structure and volatile distribution.

  5. Hydrodynamics of slip wedge and optimization of surface slip property

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The hydrodynamic load support generated by a slip wedge of a slider bearing was studied. The surface slip property was optimized so that a maximum hydrodynamic load support could be obtained. A multi-linearity method was given for the slip control equation of two-dimensional (2-D) wall slip. We investigated 2-D wall slip and the hydrodynamics of a finite length bearing with any values of the surface limiting shear stress. It was found that the hydrodynamic effect of the slip wedge is greater than the traditional geometrical convergent-wedge. Even though the geo- metrical gap is a parallel or divergent sliding gap, the slip wedge still gives rise to a very big hydrodynamic pressure. The optimized slip wedge can give rise to a hy- drodynamic load support as high as 2.5 times of what the geometrical conver- gent-wedge can produce. Wall slip usually gives a small surface friction.

  6. Hydrodynamics of slip wedge and optimization of surface slip property

    Institute of Scientific and Technical Information of China (English)

    MA GuoJun; WU ChengWei; ZHOU Ping

    2007-01-01

    The hydrodynamic load support generated by a slip wedge of a slider bearing was studied. The surface slip property was optimized so that a maximum hydrodynamic load support could be obtained. A multi-linearity method was given for the slip control equation of two-dimensional (2-D) wall slip. We investigated 2-D wall slip and the hydrodynamics of a finite length bearing with any values of the surface limiting shear stress. It was found that the hydrodynamic effect of the slip wedge is greater than the traditional geometrical convergent-wedge. Even though the geometrical gap is a parallel or divergent sliding gap, the slip wedge still gives rise to a very big hydrodynamic pressure. The optimized slip wedge can give rise to a hydrodynamic load support as high as 2.5 times of what the geometrical convergent-wedge can produce. Wall slip usually gives a small surface friction.

  7. Phase transitions and interface fluctuations in double wedges and bi-pyramids with competing surface fields

    Science.gov (United States)

    Müller, M.; Milchev, A.; Binder, K.; Landau, D. P.

    2008-08-01

    The interplay between surface and interface effects on binary AB mixtures that are confined in unconventional geometries is investigated by Monte Carlo simulations and phenomenological considerations. Both double-wedge and bi-pyramid confinements are considered and competing surface fields are applied at the two opposing halves of the system. Below the bulk critical temperature, domains of opposite order parameter are stabilized at the corresponding corners and an interface runs across the middle of the bi-partite geometry. Upon decreasing the temperature further one encounters a phase transition at which the AB symmetry is broken. The interface is localized in one of the two wedges or pyramids, respectively, and the order parameter is finite. In both cases, the transition becomes discontinuous in the thermodynamic limit but it is not a first-order phase transition. In an antisymmetric double wedge geometry the transition is closely related to the wedge-filling transition. Choosing the ratio of the cross-section L × L of the wedge and its length L y according to L y / L 3 = const., simulations and phenomenological consideration show that the new type of phase transition is characterized by critical exponents α = 3/4, β = 0, and γ = 5/4 for the specific heat, order parameter, and susceptibility, respectively. In an antisymmetric bi-pyramid the transition occurs at the cone-filling transition of a single pyramid. The important critical fluctuations are associated with the uniform translation of the interface and they can be described by a Landau-type free energy. Monte Carlo results provide evidence that the coefficients of this Landau-type free energy exhibit a system-size dependence, which gives rise to critical amplitudes that diverge with system size and result in a transition that becomes discontinuous in the thermodynamic limit.

  8. Knee abduction angular impulses during prolonged running with wedged insoles.

    Science.gov (United States)

    Lewinson, Ryan T; Worobets, Jay T; Stefanyshyn, Darren J

    2013-07-01

    Wedged insoles may produce immediate effects on knee abduction angular impulses during running; however, it is currently not known whether these knee abduction angular impulse magnitudes are maintained throughout a run when fatigue sets in. If changes occur, this could affect the clinical utility of wedged insoles in treating conditions such as patellofemoral pain. Thus, the purpose of this study was to determine whether knee abduction angular impulses are altered during a prolonged run with wedged insoles. It was hypothesized that knee abduction angular impulses would be reduced following a prolonged run with wedged insoles. Nine healthy runners participated. Runners were randomly assigned to either a 6-mm medial wedge condition or a 6-mm lateral wedge condition and then ran continuously overground for 30 min. Knee abduction angular impulses were quantified at 0 and 30 min using a gait analysis procedure. After 2 days, participants returned to perform the same test but with the other wedge type. Two-way repeated-measures analysis of variance was used to evaluate main effects of wedge condition and time and interactions between wedge condition and time (α = 0.05). Paired t-tests were used for post hoc analysis (α = 0.01). No interaction effects (p = 0.958) were found, and knee abduction angular impulses were not significantly different over time (p = 0.384). Lateral wedge conditions produced lesser knee abduction angular impulses than medial conditions at 0 min (difference of 2.79 N m s, p = 0.006) and at 30 min (difference of 2.76 N m s, p < 0.001). It is concluded that significant knee abduction angular impulse changes within wedge conditions do not occur during a 30-min run. Additionally, knee abduction angular impulse differences between wedge conditions are maintained during a 30-min run.

  9. Plastic deformation of a wedge by a sliding punch

    Science.gov (United States)

    Nepershin, R. I.

    2016-11-01

    We present a self-similar solution of the problem of deformation of an ideally plastic wedge by a sliding punch with regard to contact friction; such a solution generalizes the well-known solutions of the problem of wedge penetration into a plastic half-space and of compression of an ideally plastic wedge by a plane punch. The problem is of interest for modeling the processes of plastic deformation of rough surfaces of metal pieces by a rigid tool.

  10. Optimal clinical implementation of the Siemens virtual wedge.

    Science.gov (United States)

    Walker, C P; Richmond, N D; Lambert, G D

    2003-01-01

    Installation of a modern high-energy Siemens Primus linear accelerator at the Northern Centre for Cancer Treatment (NCCT) provided the opportunity to investigate the optimal clinical implementation of the Siemens virtual wedge filter. Previously published work has concentrated on the production of virtual wedge angles at 15 degrees, 30 degrees, 45 degrees, and 60 degrees as replacements for the Siemens hard wedges of the same nominal angles. However, treatment plan optimization of the dose distribution can be achieved with the Primus, as its control software permits the selection of any virtual wedge angle from 15 degrees to 60 degrees in increments of 1 degrees. The same result can also be produced from a combination of open and 60 degrees wedged fields. Helax-TMS models both of these modes of virtual wedge delivery by the wedge angle and the wedge fraction methods respectively. This paper describes results of timing studies in the planning of optimized patient dose distributions by both methods and in the subsequent treatment delivery procedures. Employment of the wedge fraction method results in the delivery of small numbers of monitor units to the beam's central axis; therefore, wedge profile stability and delivered dose with low numbers of monitor units were also investigated. The wedge fraction was proven to be the most efficient method when the time taken for both planning and treatment delivery were taken into consideration, and is now used exclusively for virtual wedge treatment delivery in Newcastle. It has also been shown that there are no unfavorable dosimetric consequences from its practical implementation.

  11. Vibration frequencies of a constrained cantilever wedge

    Science.gov (United States)

    Craver, W. Lionel, Jr.; Lu, Yangshan

    1989-05-01

    This paper presents the solution for the natural frequencies of a beam tapered in one direction, or a wedge, with both a rotational and a translational constraint at a position along the length of the beam. The eigenfrequencies were determined using an incremental search and bisection method, accurate to the fourth decimal place. The taper ratio was varied from 1.4 to 5.0 and the dimensionless spring constants were varied from 0 to 1000. Graphs are provided to illustrate some results.

  12. Impingement of water droplets on wedges and double-wedge airfoils at supersonic speeds

    Science.gov (United States)

    Serafini, John S

    1954-01-01

    An analytical solution has been obtained for the equations of motion of water droplets impinging on a wedge in a two-dimensional supersonic flow field with a shock wave attached to the wedge. The closed-form solution yields analytical expressions for the equation of the droplet trajectory, the local rate of impingement and the impingement velocity at any point on the wedge surface, and the total rate of impingement. The analytical expressions are utilized to determine the impingement on the forward surfaces of diamond airfoils in supersonic flow fields with attached shock waves. The results presented include the following conditions: droplet diameters from 2 to 100 microns, pressure altitudes from sea level to 30,000 feet, free-stream static temperatures from 420 degrees r, free stream Mach numbers from 1.1 to 2.0, semiapex angles for the wedge from 1.14 degrees to 7.97 degrees, thickness-to-chord ratios for the diamond airfoil from 0.02 to 0.14, chord lengths from 1 to 20 feet, and angles of attack from zero to the inverse tangent of the airfoil thickness-to-chord ratio.

  13. Global Existence of a Shock for the Supersonic Flow Past a Curved Wedge

    Institute of Scientific and Technical Information of China (English)

    Hui Cheng YIN

    2006-01-01

    This note is devoted to the study of the global existence of a shock wave for the supersonic flow past a curved wedge. When the curved wedge is a small perturbation of a straight wedge and the angle of the wedge is less than some critical value, we show that a shock attached at the wedge will exist globally.

  14. Heuristica de dos-etapas para el problema de corte de piezas con guillotinado bidimensional

    Directory of Open Access Journals (Sweden)

    Juan Gabriel Correa Medina

    2014-08-01

    Full Text Available En un ambiente altamente competitivo, el problema de corte de guillotina bidimensional es un elemento clave en la reducción de costos. Este problema tiene una amplia gama de aplicaciones en industrias cuyos procesos de corte de materiales se realizan con máquinas que sólo permiten cortes de un extremo a otro. En este trabajo se presenta un algoritmo de dos etapas usando metaheurísticas para acomodar en una sola placa de ancho conocido y longitud infinita, un conjunto de ítems rectangulares fuertemente heterogéneos que pueden ser rotados 90°. El objetivo es minimizar la longitud requerida de la placa procurando la acumulación del desperdicio. En la primera etapa se aplica un algoritmo de búsqueda tabú para determinar el orden en que se acomodan los ítems. En la segunda, se busca determinar el mejor acomodo de los ítems en la placa mediante un algoritmo de recocido simulado. Se experimenta con un conjunto de instancias conocidas. Los resultados muestran que la rotación de piezas favorece la obtención de soluciones que igualan al menos las reportadas previamente en la literatura y que la concentración de los desperdicios incrementa su posibilidad de reutilización. Into a highly competitive environment, two-dimensional guillotine’s cut problem is an elementary key to cost reduction. This problem has a wide variety of applications into factories related to processes material cut. Cuts are done by machines which cut from one edge to other. A two stage algorithm is shown to place a finite set of items in a single plate with a known width and infinite length, using metaheuristics. All items are rectangular, mostly are distinct itself and each one can only be rotated 90 degrees at once. Main objective is minimization of length required by plate and waste accumulation were compacted as much as possible. First stage determines the order from items placed by using a tabu search algorithm. Second stage tries improving the order previous

  15. Automated screening system for retinal health using bi-dimensional empirical mode decomposition and integrated index.

    Science.gov (United States)

    Acharya, U Rajendra; Mookiah, Muthu Rama Krishnan; Koh, Joel E W; Tan, Jen Hong; Bhandary, Sulatha V; Rao, A Krishna; Fujita, Hamido; Hagiwara, Yuki; Chua, Chua Kuang; Laude, Augustinus

    2016-08-01

    Posterior Segment Eye Diseases (PSED) namely Diabetic Retinopathy (DR), glaucoma and Age-related Macular Degeneration (AMD) are the prime causes of vision loss globally. Vision loss can be prevented, if these diseases are detected at an early stage. Structural abnormalities such as changes in cup-to-disc ratio, Hard Exudates (HE), drusen, Microaneurysms (MA), Cotton Wool Spots (CWS), Haemorrhages (HA), Geographic Atrophy (GA) and Choroidal Neovascularization (CNV) in PSED can be identified by manual examination of fundus images by clinicians. However, manual screening is labour-intensive, tiresome and time consuming. Hence, there is a need to automate the eye screening. In this work Bi-dimensional Empirical Mode Decomposition (BEMD) technique is used to decompose fundus images into 2D Intrinsic Mode Functions (IMFs) to capture variations in the pixels due to morphological changes. Further, various entropy namely Renyi, Fuzzy, Shannon, Vajda, Kapur and Yager and energy features are extracted from IMFs. These extracted features are ranked using Chernoff Bound and Bhattacharyya Distance (CBBD), Kullback-Leibler Divergence (KLD), Fuzzy-minimum Redundancy Maximum Relevance (FmRMR), Wilcoxon, Receiver Operating Characteristics Curve (ROC) and t-test methods. Further, these ranked features are fed to Support Vector Machine (SVM) classifier to classify normal and abnormal (DR, AMD and glaucoma) classes. The performance of the proposed eye screening system is evaluated using 800 (Normal=400 and Abnormal=400) digital fundus images and 10-fold cross validation method. Our proposed system automatically identifies normal and abnormal classes with an average accuracy of 88.63%, sensitivity of 86.25% and specificity of 91% using 17 optimal features ranked using CBBD and SVM-Radial Basis Function (RBF) classifier. Moreover, a novel Retinal Risk Index (RRI) is developed using two significant features to distinguish two classes using single number. Such a system helps to reduce eye

  16. Molecular depth profiling by wedged crater beveling.

    Science.gov (United States)

    Mao, Dan; Lu, Caiyan; Winograd, Nicholas; Wucher, Andreas

    2011-08-15

    Time-of-flight secondary ion mass spectrometry and atomic force microscopy are employed to characterize a wedge-shaped crater eroded by a 40-keV C(60)(+) cluster ion beam on an organic film of Irganox 1010 doped with Irganox 3114 delta layers. From an examination of the resulting surface, the information about depth resolution, topography, and erosion rate can be obtained as a function of crater depth for every depth in a single experiment. It is shown that when measurements are performed at liquid nitrogen temperature, a constant erosion rate and reduced bombardment induced surface roughness is observed. At room temperature, however, the erosion rate drops by ∼(1)/(3) during the removal of the 400 nm Irganox film and the roughness gradually increased to from 1 nm to ∼4 nm. From SIMS lateral images of the beveled crater and AFM topography results, depth resolution was further improved by employing glancing angles of incidence and lower primary ion beam energy. Sub-10 nm depth resolution was observed under the optimized conditions on a routine basis. In general, we show that the wedge-crater beveling is an important tool for elucidating the factors that are important for molecular depth profiling experiments.

  17. Ice-Creams and Wedge Graphs

    CERN Document Server

    Ackerman, Eyal; Pinchasi, Rom

    2011-01-01

    We show that for every compact convex set $S$ in the plane and every $0 < \\alpha < \\pi$, there exist a point $O$ and two supporting lines to $S$ passing through $O$ and touching $S$ at two \\emph{single points} $X$ and $Y$, respectively, such that $|OX|=|OY|$ and the angle between the two lines has measure $\\alpha$. As a consequence, we provide a simplified proof to the following result by Carmi, Katz, Lotker, and Ros\\'en \\cite{CKLR10}. Given a set of $\\frac{\\pi}{3}$-directional antennas (that is, antennas each of which can communicate along a wedge of angle $\\frac{\\pi}{3}$), one can always assign a direction to each antenna such that the resulting communication graph is connected, where two antennas can communicate if and only if each lies in the wedge assigned to the other. In fact we obtain a much stronger and optimal result (see Theorem \\ref{theorem:main}) saying in particular that one can chose the directions of the antennas so that the communication graph has diameter $\\le 4$.

  18. 49 CFR 215.113 - Defective plain bearing wedge.

    Science.gov (United States)

    2010-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION RAILROAD FREIGHT CAR SAFETY STANDARDS Freight Car Components Suspension System § 215.113 Defective plain bearing wedge. A railroad may not place or continue in service a car, if a plain bearing wedge on that car is— (a) Missing; (b) Cracked; (c) Broken; or (d) Not...

  19. 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.

  20. Characterization of CNRS Fizeau wedge laser tuner

    Science.gov (United States)

    A fringe detection and measurement system was constructed for use with the CNRS Fizeau wedge laser tuner, consisting of three circuit boards. The first board is a standard Reticon RC-100 B motherboard which is used to provide the timing, video processing, and housekeeping functions required by the Reticon RL-512 G photodiode array used in the system. The sampled and held video signal from the motherboard is processed by a second, custom fabricated circuit board which contains a high speed fringe detection and locating circuit. This board includes a dc level discriminator type fringe detector, a counter circuit to determine fringe center, a pulsed laser triggering circuit, and a control circuit to operate the shutter for the He-Ne reference laser beam. The fringe center information is supplied to the third board, a commercial single board computer, which governs the data collection process and interprets the results.

  1. Analysis of stress-strain state on top of a rectangular wedge

    Directory of Open Access Journals (Sweden)

    Frishter Lyudmila Yur'evna

    2014-05-01

    Full Text Available Modeling singular solutions of the elasticity theory problems, which are determined by geometric factor - bird's mouth of the edge, make it necessary to analyze the solutions with some peculiarity, which are obtained experimentally with the help of photoelasticity method. In this article the peculiar stress-strain state is analyzed on the example of the known experimental solutions for a wedge under a concentrated force obtained by M. Frocht. Solution analysis for a wedge with a power-type peculiarity obtained experimentally by photoelasticity method, helps to detach a singular solution field, where fringe contour is not visible. Due to idealization of the boundary shape and loading technique, infinitely large stresses arise, which are obtained as a singular solution of the boundary problem in a planar domain. Comparison of theoretical and experimental solutions obtained for a wedge shows areas of overlap and areas of significant and insignificant differences as a result of the inability to experimentally apply the force to a single point.

  2. The Tax Wedge in Slovenia: International Comparison and Policy Recommendations

    Directory of Open Access Journals (Sweden)

    Primož Dolenc

    2005-09-01

    Full Text Available When taxes on labor are introduced, a “tax wedge” appears between the labor costs paid by the employer (gross wage and the net wage received by an employee. At a certain level of wage, a higher tax wedge increases unemployment and decreases employment, all other things being equal. The paper tackles three main questions: the characteristics of the tax wedge, unemployment and employment rates in OECD countries in the recent past, tax wedge policy in the EU15 and the new EU members and the tax system and its effects on the unemployment and employment rates in Slovenia. We found that the OECD countries can be classified into two groups of countries if the tax wedge, the unemployment rate and the employment rate are taken into consideration. The first group is the high tax wedge, high unemployment rate and low employment rate group of countries, whereas the other group has the opposite characteristics. European member states (old and new have on average a higher tax burden on labor than the OECD average, consequently suffering from higher unemployment rates. Slovenia has an unreasonably high tax wedge; in the EU only Belgium and Germany have a higher tax burden. According to previous and our empirical findings we suggest that Slovenia could benefit from a reduction in the tax wedge.

  3. Metric Equivalence of the Bidimensional Acculturation Scale, the Satisfaction with Life Scale, and the Self-Construal Scale across Spanish and English Language Versions

    Science.gov (United States)

    Singelis, Theodore M.; Yamada, Ann Marie; Barrio, Concepcion; Laney, Joshua Harrison; Her, Pa; Ruiz-Anaya, Alejandrina; Lennertz, Sara Terwilliger

    2006-01-01

    The metric equivalence of translated scales is often in question but seldom examined. This study presents test-retest data that support the metric equivalence of the Spanish and English language versions of three measures: the Bidimensional Acculturation Scale, the Satisfaction with Life Scale, and the Self-Construal Scale. Participants were…

  4. Group sequential designs for stepped-wedge cluster randomised trials.

    Science.gov (United States)

    Grayling, Michael J; Wason, James Ms; Mander, Adrian P

    2017-06-01

    The stepped-wedge cluster randomised trial design has received substantial attention in recent years. Although various extensions to the original design have been proposed, no guidance is available on the design of stepped-wedge cluster randomised trials with interim analyses. In an individually randomised trial setting, group sequential methods can provide notable efficiency gains and ethical benefits. We address this by discussing how established group sequential methodology can be adapted for stepped-wedge designs. Utilising the error spending approach to group sequential trial design, we detail the assumptions required for the determination of stepped-wedge cluster randomised trials with interim analyses. We consider early stopping for efficacy, futility, or efficacy and futility. We describe first how this can be done for any specified linear mixed model for data analysis. We then focus on one particular commonly utilised model and, using a recently completed stepped-wedge cluster randomised trial, compare the performance of several designs with interim analyses to the classical stepped-wedge design. Finally, the performance of a quantile substitution procedure for dealing with the case of unknown variance is explored. We demonstrate that the incorporation of early stopping in stepped-wedge cluster randomised trial designs could reduce the expected sample size under the null and alternative hypotheses by up to 31% and 22%, respectively, with no cost to the trial's type-I and type-II error rates. The use of restricted error maximum likelihood estimation was found to be more important than quantile substitution for controlling the type-I error rate. The addition of interim analyses into stepped-wedge cluster randomised trials could help guard against time-consuming trials conducted on poor performing treatments and also help expedite the implementation of efficacious treatments. In future, trialists should consider incorporating early stopping of some kind into

  5. Stable and Critical Noncohesive Coulomb Wedges: Exact Elastic Solutions

    Science.gov (United States)

    Wang, K.; Hu, Y.

    2004-12-01

    The theory of critically tapered Coulomb wedge has been successfully applied to model active fold-and-thrust belts or submarine accretionary prisms. Brittle mountain building is episodic in nature, controlled by changes in basal friction, erosion and sedimentation, and hydrogeology. Sediment accretion may be modulated by great subduction earthquakes. Between deformation episodes and/or during transition between compressional and extensional tectonics, the Coulomb wedges are stable (i.e., supercritical), to which the critical taper theory does not apply. In this work, we provide an exact elastic solution for stable wedges based on Airy stress functions. The stress equilibrium equation and definition of basal friction and basal and internal pore fluid pressure ratios are exactly the same as those used for Dahlen's [1984] exact solution for critical noncohesive Coulomb wedges, but internal friction μ becomes irrelevant. Given elastic - perfectly Coulomb-plastic rheology, for stresses in a wedge on the verge of Coulomb failure there must co-exist a critical taper solution involving μ and a unique equivalent elastic solution not involving μ . Our elastic solution precisely reduces to Dahlen's critical taper solution for critical conditions. For stable conditions, normal stress perpendicular to the surface slope σ z and shear stress τ xz are identical with those in a critical taper, but the slope-parallel normal stress is different. The elastic solution is also generally applicable to purely elastic wedges and useful for modeling geodetic observations. A stable noncohesive Coulomb wedge differs from a general elastic wedge in that its upper and lower surfaces stay at zero curvature during loading. Dahlen, F.A. (1984), Noncohesive critical Coulomb wedges: An exact solution, JGR, 89, 10,125-10,133.

  6. Domain evolution and polarization of continuously graded ferroelectric films

    Energy Technology Data Exchange (ETDEWEB)

    Roytburd, A.; Roytburd, V.

    2008-01-01

    A thermodynamic analysis of graded ferroelectric films demonstrates that in the equilibrium state the films are subdivided into a single-domain band and a polydomain band which consists of wedge-shape domains. Polarization under an external electrostatic field proceeds through an inter-band boundary movement due to growth or shrinkage of the wedge domains. It is shown how the domain structure and evolution are determined by the principal characteristics of the film: the distribution of the spontaneous polarization and dielectric constant. Graded films exhibit a sharp increase of polarization with the field for weak fields, with a drop of the dielectric constant when the field is increasing. A general approach to finding the dependence of the displacement and the wedge-domain shape on the field as well as analytical solutions for the p{sup 4} Landau-Devonshire and parabolic potentials are presented.

  7. Employment and productivity: The role of the tax wedge

    Directory of Open Access Journals (Sweden)

    Andrea FESTA

    2015-11-01

    Full Text Available After the economic crisis, many countries aim at reducing unemployment and foster productivity. To address these issues one of the most common policy indications recommends lowering the tax wedge on labour in order to increase employment and growth. As a consequence, a review of the empirical studies focused on the relation between tax wedge, employment and productivity is an useful and demanding exercise, especially in those European countries where the topic is on the front page of the domestic policy debate because the productivity growth is low and the tax wedge on labour is high.

  8. Theoretical modelling of a bi-dimensional U-shaped surface plasmon resonance based fibre optic sensor for sensitivity enhancement

    Energy Technology Data Exchange (ETDEWEB)

    Verma, R K; Gupta, B D [Physics Department, Indian Institute of Technology Delhi, New Delhi-110016 (India)], E-mail: bdgupta@physics.iitd.ernet.in

    2008-05-07

    Theoretical analysis of a surface plasmon resonance based fibre optic sensor with a uniform semi-metal coated U-shaped probe is carried out using a bi-dimensional model. All the rays of the p-polarized light launched in the fibre and their electric vectors are assumed to be confined in the plane of bending of the U-shaped probe. The effect of the bending radius of the probe on the sensitivity of the sensor is studied. The study shows that as the bending radius of the probe decreases the sensitivity of the sensor increases. For the light launching conditions used, the maximum sensitivity achieved is several times more than that reported for a fibre optic tapered probe. In addition to high sensitivity, the most advantageous feature of a U-shaped probe is that it can be used as a point sensor.

  9. Um algoritmo genético híbrido para o problema de corte industrial bidimensional

    Directory of Open Access Journals (Sweden)

    Ademir Aparecido Constantino

    2002-04-01

    Full Text Available O objetivo deste trabalho é a implementação de um algoritmo eficaz que solucione o problema de corte bi-dimensional, ou seja, que encontre uma solução muito boa (viável e rápida para este problema, otimizando o uso das chapas para diminuir o desperdício gerado com os cortes que são feitos sobre a mesma. Para a sua implementação, foram utilizados Algoritmos Genéticos como uma técnica de otimização, e o Bottom-Left como uma técnica de encaixe das peças na chapa retangular. Alguns testes foram executados e os resultados ficaram no máximo 10% acima da solução ótima.

  10. Bidimensional Data Allow for Better Age Estimation on Immature Specimens than Unidimensional Data: A Preliminary Study on the Ilium.

    Science.gov (United States)

    Daumas, Mathilde; Chaumoître, Kathia; Adalian, Pascal; Marchal, François

    2016-03-01

    Most biometric age estimation methods used in anthropological and forensic science for juveniles are based on unidimensional measurements (length or width). Here, a new method using bidimensional data was tested. A 3D morphometric analysis was performed on 108 CT scans of ilium bone of juveniles (from 20 gestational weeks to 12 years old). The sample was divided into training and validation groups. Best predictors were determined by comparing the efficiency of each variable (length, width, area, and module: a product of length and width). We established linear and polynomial regressions for each parameter for both sides. Applying the equations to the validation sample showed no significant difference between real and predicted ages. For age estimation, the area and module parameters yielded better results than unidimensional measurements. The results from this preliminary study were highly conclusive, and it would be interesting to extend the work, covering larger samples, and other bones.

  11. A case report of an autistic boy. Selective responding to components of bidimensional visual and auditory stimuli.

    Science.gov (United States)

    Edwards, J L; Shigley, R H; Edwards, R P

    1976-06-01

    A case study was reported in which a 9-year-old male autistic boy was initially trained to discriminate between two auditory stimuli and two visual stimuli. He was then tested for overselective responding to bidimensional combinations of the four stimuli. It was hypothesized that the overselectivity results reported in previous studies were partially a function of a procedure in which autistic children were reinforced for responding in the presence of a multidimensional stimulus complex and then tested with individual stimuli. The child in the present investigation, with the alternative procedure, did not demonstrate overselective responding. Two interpretations of the results were presented, neither of which was consistent with an overselectivity theory. Future research should delineate the specific conditions which produce overselective responding, and suggest methods to facilitate more adaptive responding of autistic children.

  12. Simulation of a viscous fluid spreading by a bidimensional shallow water model

    CERN Document Server

    Di Martino, Bernard; Paoli, Jean-Martin; Simonnet, Pierre; 10.1016/j.apm.2011.01.015

    2011-01-01

    In this paper we propose a numerical method to solve the Cauchy problem based on the viscous shallow water equations in an horizontally moving domain. More precisely, we are interested in a flooding and drying model, used to modelize the overflow of a river or the intrusion of a tsunami on ground. We use a non conservative form of the two-dimensional shallow water equations, in eight velocity formulation and we build a numerical approximation, based on the Arbitrary Lagrangian Eulerian formulation, in order to compute the solution in the moving domain.

  13. Flow braking and the substorm current wedge

    Science.gov (United States)

    Birn, J.; Hesse, M.; Haerendel, G.; Baumjohann, W.; Shiokawa, K.

    1999-09-01

    Recent models of magnetotail activity have associated the braking of earthward flow with dipolarization and the reduction and diversion of cross-tail current, that is, the signatures of the substorm current wedge. Estimates of the magnitude of the diverted current by Haerendel [1992] and Shiokawa et al. [1997, 1998] tend to be lower than results from computer simulations of magnetotail reconnection and tail collapse [Birn and Hesse, 1996], despite similar underlying models. An analysis of the differences between these estimates on the basis of the simulations gives a more refined picture of the diversion of perpendicular into parallel currents. The inertial currents considered by Haerendel [1992] and Shiokawa et al. [1997] contribute to the initial current reduction and diversion, but the dominant and more permanent contribution stems from the pressure gradient terms, which change in connection with the field collapse and distortion. The major effect results from pressure gradients in the z direction, rather than from the azimuthal gradients [Shiokawa et al., 1998], combined with changes in By and Bx. The reduction of the current density near the equatorial plane is associated with a reduction of the curvature drift which overcompensates changes of the magnetization current and of the gradient B drift current. In contrast to the inertial current effects, the pressure gradient effects persist even after the burst of earthward flow ends.

  14. Casimir Effect for a Semitransparent Wedge and an Annular Piston

    CERN Document Server

    Milton, Kimball A; Kirsten, Klaus

    2009-01-01

    We consider the Casimir energy due to a massless scalar field in a geometry of an infinite wedge closed by a Dirichlet circular cylinder, where the wedge is formed by $\\delta$-function potentials, so-called semitransparent boundaries. A finite expression for the Casimir energy corresponding to the arc and the presence of both semitransparent potentials is obtained, from which the torque on the sidewalls can be derived. The most interesting part of the calculation is the nontrivial nature of the angular mode functions. Numerical results are obtained which are closely analogous to those recently found for a magnetodielectric wedge, with the same speed of light on both sides of the wedge boundaries. Alternative methods are developed for annular regions with radial semitransparent potentials, based on reduced Green's functions for the angular dependence, which allows calculations using the multiple-scattering formalism. Numerical results corresponding to the torque on the radial plates are likewise computed, whic...

  15. Electrodynamic Casimir effect in a medium-filled wedge.

    Science.gov (United States)

    Brevik, Iver; Ellingsen, Simen A; Milton, Kimball A

    2009-04-01

    We re-examine the electrodynamic Casimir effect in a wedge defined by two perfect conductors making dihedral angle alpha=pi/p. This system is analogous to the system defined by a cosmic string. We consider the wedge region as filled with an azimuthally symmetric material, with permittivity and permeability epsilon1, micro1 for distance from the axis ra. The results are closely related to those for a circular-cylindrical geometry, but with noninteger azimuthal quantum number mp. Apart from a zero-mode divergence, which may be removed by choosing periodic boundary conditions on the wedge, and may be made finite if dispersion is included, we obtain finite results for the free energy corresponding to changes in a for the case when the speed of light is the same inside and outside the radius a , and for weak coupling, |epsilon1-epsilon2|cosmic string, situated along the cusp line of the pre-existing wedge.

  16. ELASTIC INTERACTION BETWEEN WEDGE DISCLINATION DIPOLE AND INTERNAL CRACK

    Institute of Scientific and Technical Information of China (English)

    FANG Qi-hong; LIU You-wen

    2006-01-01

    The system of a wedge disclination dipole interacting with an internal crack was investigated. By using the complex variable method, the closed form solutions of complex potentials to this problem were presented. The analytic formulae of the physics variables, such as stress intensity factors at the tips of the crack produced by the wedge disclination dipole and the image force acting on disclination dipole center were obtained.The influence of the orientation, the dipole arm and the location of the disclination dipole on the stress intensity factors was discussed in detail. Furthermore, the equilibrium position of the wedge disclination dipole was also examined. It is shown that the shielding or antishielding effect of the wedge disclination to the stress intensity factors is significant when the disclination dipole moves to the crack tips.

  17. 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...

  18. Structure and Kinematics of the Indo-Burmese Wedge

    Science.gov (United States)

    Maurin, T.; Rangin, C.

    2007-12-01

    The Burma subduction trench and the associated Indo Burmese wedge mark the present eastern boundary of the Indian plate in the northern Bengal area. The initiation, duration and history of the Bengal crust subduction beneath Burma is still debated. The aim of this paper is to provide a structural and kinematic analysis of the Indo- Burmese wedge in order to better constraints the Bengal crust subduction history beneath Burma. On the basis of field observations, seismic reflection data interpretation and well logs data we present a structural analysis of the Outer Indo-Burmese Wedge. We also constrain the onset of this Outer Wedge to be younger than 2Ma, implying a recent and fast westward growth (~10cm/yr) since Late Pliocene in close relationship with the onset of the Shillong plateau. Restoration process of a synthetic cross section through the Outer Wedge allowed us to estimate the amount of EW shortening accommodated in the Outer Wedge to be 5.1mm/yr since 2Ma. These results combined with previous available GPS data from central Myanmar suggest strain partitioning at wedge scale. The core of the wedge is affected by shear deformation and acts as a buttress for a frontal wedge that accommodates a more compressive strain component. Finally we propose that the main characteristic of the Indo-Burmese wedge growth mechanism is the progressive incorporation of the most internal part of the wedge, formerly affected by transpressive thin-skinned tectonics, to the buttress where they are subsequently affected by shear deformation. The crustal structure boarding the newly formed buttress seems to be guided by the subducting crust fabrics. We are in favour of a very recent (Late Miocene) onset of the present Indian crust subduction beneath Burma coeval with the global plate kinematics reorganisation related to the Indian/Australian plate spliting. This subduction postdates the Indo Burmese range onset that must have started in early Miocene. This range first began to

  19. 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.

  20. Optical refractometry based on Fresnel diffraction from a phase wedge.

    Science.gov (United States)

    Tavassoly, M Taghi; Saber, Ahad

    2010-11-01

    A method that utilizes the Fresnel diffraction of light from the phase step formed by a transparent wedge is introduced for measuring the refractive indices of transparent solids, liquids, and solutions. It is shown that, as a transparent wedge of small apex angle is illuminated perpendicular to its surface by a monochromatic parallel beam of light, the Fresnel fringes, caused by abrupt change in refractive index at the wedge lateral boundary, are formed on a screen held perpendicular to the beam propagation direction. The visibility of the fringes varies periodically between zero and 1 in the direction normal to the wedge apex. For a known or measured apex angle, the wedge refractive index is obtained by measuring the period length by a CCD. To measure the refractive index of a transparent liquid or solution, the wedge is installed in a transparent rectangle cell containing the sample. Then, the cell is illuminated perpendicularly and the visibility period is measured. By using modest optics, one can measure the refractive index at a relative uncertainty level of 10(-5). There is no limitation on the refractive index range. The method can be applied easily with no mechanical manipulation. The measuring apparatus can be very compact with low mechanical and optical noises.

  1. Conceptual design of heavy ion beam compression using a wedge

    Directory of Open Access Journals (Sweden)

    Jonathan C. Wong

    2015-10-01

    Full Text Available Heavy ion beams are a useful tool for conducting high energy density physics (HEDP experiments. Target heating can be enhanced by beam compression, because a shorter pulse diminishes hydrodynamic expansion during irradiation. A conceptual design is introduced to compress ∼100  MeV/u to ∼GeV/u heavy ion beams using a wedge. By deflecting the beam with a time-varying field and placing a tailor-made wedge amid its path downstream, each transverse slice passes through matter of different thickness. The resulting energy loss creates a head-to-tail velocity gradient, and the wedge shape can be designed by using stopping power models to give maximum compression at the target. The compression ratio at the target was found to vary linearly with (head-to-tail centroid offset/spot radius at the wedge. The latter should be approximately 10 to attain tenfold compression. The decline in beam quality due to projectile ionization, energy straggling, fragmentation, and scattering is shown to be acceptable for well-chosen wedge materials. A test experiment is proposed to verify the compression scheme and to study the beam-wedge interaction and its associated beam dynamics, which will facilitate further efforts towards a HEDP facility.

  2. Quantificação do líquido amniótico pela ultra-sonografia tridimensional e bidimensional no primeiro trimestre da gestação

    OpenAIRE

    Gadelha,Patricia Spara; Costa,Antonio Gadelha da; Mauad Filho,Francisco; El Beitune, Patrícia; Ferreira, Adilson Cunha

    2006-01-01

    OBJETIVO: quantificar os valores do líquido amniótico no primeiro trimestre da gestação, em fetos normais, por meio de ultra-sonografia tridimensional e bidimensional. MÉTODOS: foram avaliados 25 fetos normais, da 8ª à 11ª semana de gestação. O estudo foi do tipo prospectivo longitudinal. As medidas do volume de líquido amniótico foram obtidas por meio de ultra-sonografia endovaginal, modos tridimensional e bidimensional. O estudo bidimensional consistiu em determinar o volume por cálculo mat...

  3. Benchmarking analogue models of brittle thrust wedges

    Science.gov (United States)

    Schreurs, Guido; Buiter, Susanne J. H.; Boutelier, Jennifer; Burberry, Caroline; Callot, Jean-Paul; Cavozzi, Cristian; Cerca, Mariano; Chen, Jian-Hong; Cristallini, Ernesto; Cruden, Alexander R.; Cruz, Leonardo; Daniel, Jean-Marc; Da Poian, Gabriela; Garcia, Victor H.; Gomes, Caroline J. S.; Grall, Céline; Guillot, Yannick; Guzmán, Cecilia; Hidayah, Triyani Nur; Hilley, George; Klinkmüller, Matthias; Koyi, Hemin A.; Lu, Chia-Yu; Maillot, Bertrand; Meriaux, Catherine; Nilfouroushan, Faramarz; Pan, Chang-Chih; Pillot, Daniel; Portillo, Rodrigo; Rosenau, Matthias; Schellart, Wouter P.; Schlische, Roy W.; Take, Andy; Vendeville, Bruno; Vergnaud, Marine; Vettori, Matteo; Wang, Shih-Hsien; Withjack, Martha O.; Yagupsky, Daniel; Yamada, Yasuhiro

    2016-11-01

    We performed a quantitative comparison of brittle thrust wedge experiments to evaluate the variability among analogue models and to appraise the reproducibility and limits of model interpretation. Fifteen analogue modeling laboratories participated in this benchmark initiative. Each laboratory received a shipment of the same type of quartz and corundum sand and all laboratories adhered to a stringent model building protocol and used the same type of foil to cover base and sidewalls of the sandbox. Sieve structure, sifting height, filling rate, and details on off-scraping of excess sand followed prescribed procedures. Our analogue benchmark shows that even for simple plane-strain experiments with prescribed stringent model construction techniques, quantitative model results show variability, most notably for surface slope, thrust spacing and number of forward and backthrusts. One of the sources of the variability in model results is related to slight variations in how sand is deposited in the sandbox. Small changes in sifting height, sifting rate, and scraping will result in slightly heterogeneous material bulk densities, which will affect the mechanical properties of the sand, and will result in lateral and vertical differences in peak and boundary friction angles, as well as cohesion values once the model is constructed. Initial variations in basal friction are inferred to play the most important role in causing model variability. Our comparison shows that the human factor plays a decisive role, and even when one modeler repeats the same experiment, quantitative model results still show variability. Our observations highlight the limits of up-scaling quantitative analogue model results to nature or for making comparisons with numerical models. The frictional behavior of sand is highly sensitive to small variations in material state or experimental set-up, and hence, it will remain difficult to scale quantitative results such as number of thrusts, thrust spacing

  4. Calculating dose distributions and wedge factors for photon treatment fields with dynamic wedges based on a convolution/superposition method.

    Science.gov (United States)

    Liu, H H; McCullough, E C; Mackie, T R

    1998-01-01

    A convolution/superposition based method was developed to calculate dose distributions and wedge factors in photon treatment fields generated by dynamic wedges. This algorithm used a dual source photon beam model that accounted for both primary photons from the target and secondary photons scattered from the machine head. The segmented treatment tables (STT) were used to calculate realistic photon fluence distributions in the wedged fields. The inclusion of the extra-focal photons resulted in more accurate dose calculation in high dose gradient regions, particularly in the beam penumbra. The wedge factors calculated using the convolution method were also compared to the measured data and showed good agreement within 0.5%. The wedge factor varied significantly with the field width along the moving jaw direction, but not along the static jaw or the depth direction. This variation was found to be determined by the ending position of the moving jaw, or the STT of the dynamic wedge. In conclusion, the convolution method proposed in this work can be used to accurately compute dose for a dynamic or an intensity modulated treatment based on the fluence modulation in the treatment field.

  5. Ice wedges as climate archives - opportunities and limitations

    Science.gov (United States)

    Opel, Thomas; Meyer, Hanno; Dereviagin, Alexander; Wetterich, Sebastian; Schirrmeister, Lutz

    2014-05-01

    Permafrost regions are assumed to play a major role for Global Climate Change as they are susceptible to recent warming in particular with regard to the potential release of stored fossil carbon. Permafrost serves as archive of past environmental and climate conditions (such as sedimentation processes, temperature and precipitation regimes as well as landscape and ecosystem development) over tens of thousands of years that can be traced by the study of the frozen deposits, paleontological content and ground ice. Ground ice comprises all types of ice contained in frozen ground, including pore ice, segregation ice and ice wedges. Here, we focus on ice wedges as the most promising climate archive that can be studied by stable water isotope methods analogously to glacier ice. They may be identified by their vertically oriented foliations. Ice wedges form by the repeated filling of wintertime thermal contraction cracks by snow melt water in spring. As the melt water quickly refreezes at negative ground temperature no isotopic fractionation takes place. Hence, the isotopic composition (δ18O, δD, d excess) of wedge ice is assumed to be representative of annual cold period climate conditions, i.e. winter and spring. Ice wedges are widely distributed in non-glaciated high northern latitudes, are diagnostic of permafrost and, in general, indicative of cold and stable climate conditions. They are found in continuous and discontinuous permafrost zones and may also have formed during and survived interglacials. They may provide unique paleo information that is not captured by other climate archives. Usually, ice wedges are dated by radiocarbon dating of organic material incorporated in the ice, but also 36Cl/Cl ratios have been successfully used to date ice wedges. Nevertheless reliable age determination is challenging when studying ice wedges. Here we tackle the potential of ice wedges from the Siberian and American Arctic to trace past climate changes from stable isotope

  6. 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

  7. On asymptotic time decay of solutions to a parabolic equation in unbounded domains

    Directory of Open Access Journals (Sweden)

    P. Maremonti

    1991-05-01

    Full Text Available Estimates on the asymptotic behaviour of solutions to a parabolic equation are given, when the I.B.V.P. is posed in particular domains. More precisely, the domain Ω is unbounded, unbounded in any direction, and Ω is enclosed in a wedge or in a cone of two or three-dimensional Euclidean space. It is proved that the order of decay is increasing for decreasing opening of the wedge or of the cone.

  8. Implementation of enhanced dynamic wedge in the focus rtp system.

    Science.gov (United States)

    Miften, M; Wiesmeyer, M; Beavis, A; Takahashi, K; Broad, S

    2000-01-01

    The FOCUS RTP system implementation of Varian's enhanced dynamic wedge (EDW) is presented. Calculations of both dose distributions and wedge factors (WFs) are based on segmented treatment tables (STTs). Calculating dose requires a "transmission matrix" derived from an STT to model the modified fluence from the source. The dose calculation is then performed using either the Clarkson or convolution/superposition algorithms. An initial "primary dose/monitor unit (MU) fraction" WF estimate at the weight point of symmetric and asymmetric fields is calculated from the STT as the ratio of MU delivered on the axis of the weight point divided by total MU delivered for the treatment field. In our approach, we go beyond this initial estimate with a "scatter dose" correction. This requires measured 60 degrees WFs for 5 fields. Scatter corrections derived from measured WFs are interpolated for other wedge angles and field sizes in much the same way as arbitrary wedge angle STTs are derived from a "golden STT" using the "ratio of tangents" formalism. Dose comparisons with measured distributions show good agreement to within 3% or 3 mm for 6-MV beams and all EDW angles. Agreement with measurements to within 1% is obtained for WFs in all symmetric and asymmetric fields for 6- and 10-MV beams. For large wedge angles and field sizes, this represents a significant improvement over the 3% to 4% errors often observed using the MU fraction model alone.

  9. DIMCO. A new system for mechanical and bidimensional, of nuclear fuel pins; DIMCO un nuevo sistema de calculo mecanico de combustibles nucleares

    Energy Technology Data Exchange (ETDEWEB)

    Moreno, A.

    1977-07-01

    The system developed in JEN, for: the mechanical analysis uni and bidimensional, of nuclear fuels is presented. The mathematical and numerical foundations used, are here described. And so the models developed for effects such as swelling, cracking, clad growth etc. Numerical results for several cases are presented. a) Numerical test in one and two dimensions. b) Applicability range, c) Interaction effects. d) Influence of the power history. (Author) 17 refs.

  10. Initial adaptation testing of the bidimensionally self-adapting wall of the French T2 wind tunnel, around a three-dimensional object

    Science.gov (United States)

    Archambaud, J. P.; Dor, J. B.; Mignosi, A.; Lamarche, L.

    1986-01-01

    The test series was carried out at ONERA/CERT at the T2 wind tunnel in September 1984. The objective of this series was to minimize wall interference through a bidimensional adaptation around the models, inducing tridimensional flows. For this, three different models were used, measuring either the pressures or the forces and moment of pitch (balance). The adaptation was derived from a correction computation in the compressible axisymmetric tridimensional.

  11. A bi-dimensional genome scan for prolificacy traits in pigs shows the existence of multiple epistatic QTL

    Directory of Open Access Journals (Sweden)

    Bidanel Jean P

    2009-12-01

    Full Text Available Abstract Background Prolificacy is the most important trait influencing the reproductive efficiency of pig production systems. The low heritability and sex-limited expression of prolificacy have hindered to some extent the improvement of this trait through artificial selection. Moreover, the relative contributions of additive, dominant and epistatic QTL to the genetic variance of pig prolificacy remain to be defined. In this work, we have undertaken this issue by performing one-dimensional and bi-dimensional genome scans for number of piglets born alive (NBA and total number of piglets born (TNB in a three generation Iberian by Meishan F2 intercross. Results The one-dimensional genome scan for NBA and TNB revealed the existence of two genome-wide highly significant QTL located on SSC13 (P SSC17 (P P P P P Conclusions The complex inheritance of prolificacy traits in pigs has been evidenced by identifying multiple additive (SSC13 and SSC17, dominant and epistatic QTL in an Iberian × Meishan F2 intercross. Our results demonstrate that a significant fraction of the phenotypic variance of swine prolificacy traits can be attributed to first-order gene-by-gene interactions emphasizing that the phenotypic effects of alleles might be strongly modulated by the genetic background where they segregate.

  12. Casimir effect at nonzero temperature for wedges and cylinders

    CERN Document Server

    Ellingsen, Simen Å; Milton, Kimball A

    2010-01-01

    We consider the Casimir-Helmholtz free energy at nonzero temperature $T$ for a circular cylinder and perfectly conducting wedge closed by a cylindrical arc, either perfectly conducting or isorefractive. The energy expression at nonzero temperature may be regularized to obtain a finite value, except for a singular corner term in the case of the wedge which is present also at zero temperature. Assuming the medium in the interior of the cylinder or wedge be nondispersive with refractive index $n$, the temperature dependence enters only through the non-dimensional parameter $2\\pi naT$, $a$ being the radius of the cylinder or cylindrical arc. We show explicitly that the known zero temperature result is regained in the limit $aT\\to 0$ and that previously derived high temperature asymptotics for the cylindrical shell are reproduced exactly.

  13. Dislocation Nucleation and Pileup under a Wedge Contact at Nanoscale

    Directory of Open Access Journals (Sweden)

    Y. F. Gao

    2008-01-01

    Full Text Available Indentation responses of crystalline materials have been found to be radically different at micrometer and nanometer scales. The latter is usually thought to be controlled by the nucleation of dislocations. To explore this physical process, a dislocation mechanics study is performed to determine the conditions for the nucleation of a finite number of dislocations under a two-dimensional wedge indenter, using the Rice-Thomson nucleation criterion. The configurational force on the dislocation consists of the applied force, the image force, and the interaction force between dislocations. Dislocations reach equilibrium positions when the total driving force equals the effective Peierls stress, giving a set of nonlinear equations that can be solved using the Newton-Raphson method. When the apex angle of the wedge indenter increases, the critical contact size for dislocation nucleation increases rapidly, indicating that dislocation multiplication near a blunt wedge tip is extremely difficult. This geometric dependence agrees well with experimental findings.

  14. Indentation tectonics in the accretionary wedge of middle Manila Trench

    Institute of Scientific and Technical Information of China (English)

    LI Jiabiao; JIN Xianglong; RUAN Aiguo; WU Shimin; WU Ziyin; LIU Jianhua

    2004-01-01

    Based on the multibeam morpho-tectonic analysis of the Manila Trench accretionary wedge and its indentation tectonics and the contrasting researches with other geological and geophysical data, three tectonic zones of the wedge are established, faulting features, tectonic distribution and stress mechanism for the indentation tectonicsareanalyzed,oblique subduction along Manila Trench with convergent stress of NW55. Is presented, and the relationship of the ceasing of Eastern Subbasin spreading of South China Sea Basin to the formation of subduction zone of Manila Trench is discussed. By the model analysis and regional research, it is found that the seamount subduction along Manila Trenchoes not lead to the erosion of the accretionary wedge and the oblique subduction actually is a NWWtrending obducfion of Luzon micro-plate that results from the NWW-trending displacement of the Philippine Sea plate.

  15. 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...

  16. 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.

  17. Tricritical wedge filling transitions with short-ranged forces

    Energy Technology Data Exchange (ETDEWEB)

    Romero-Enrique, J M [Departamento de Fisica Atomica, Molecular y Nuclear, Area de Fisica Teorica, Universidad de Sevilla, Apartado de Correos 1065, 41080 Sevilla (Spain); Parry, A O [Department of Mathematics, Imperial College 180 Queen' s Gate, London SW7 2BZ (United Kingdom)

    2005-11-16

    We show that the 3D wedge filling transition in the presence of short-ranged interactions can be first order or second order depending on the strength of the line tension associated with the wedge bottom. This fact implies the existence of a tricritical point characterized by a short-distance expansion which differs from the usual continuous filling transition. Our analysis is based on an effective one-dimensional model for the 3D wedge filling, which arises from the identification of the breather modes as the only relevant interfacial fluctuations. From such analysis we find a correspondence between continuous 3D filling at bulk coexistence and 2D wetting transitions with random-bond disorder.

  18. Flow Analysis for the Falkner–Skan Wedge Flow

    DEFF Research Database (Denmark)

    Bararnia, H; Haghparast, N; Miansari, M

    2012-01-01

    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......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...

  19. Molecular Depth Profiling with Cluster SIMS and Wedges

    Science.gov (United States)

    Mao, Dan; Wucher, Andreas; Winograd, Nicholas

    2009-01-01

    Secondary ion mass spectrometry and atomic force microscopy are employed to characterize a wedge-shaped crater eroded by 40 keV C60+ bombardment of a 395-nm thin film of Irganox 1010 doped with four delta layers of Irganox 3114. The wedge structure creates a laterally magnified cross section of the film. From an examination of the resulting surface, information about depth resolution, topography and erosion rate can be obtained as a function of crater depth in a single experiment. This protocol provides a straightforward way to determine the parameters necessary to characterize molecular depth profiles, and to obtain an accurate depth scale for erosion experiments. PMID:19968247

  20. Surgical treatment of idiopathic syringomyelia: Silastic wedge syringosubarachnoid shunting technique

    Directory of Open Access Journals (Sweden)

    Teck M Soo

    2014-01-01

    Conclusions: Shunting procedures for the syringomyelia disease spectrum have been criticized due to the inconsistent long-term outcomes. This surgical technique used to treat symptomatic idiopathic syringomyelia has been devised based on our intraoperative experience, surgical outcomes, and evaluation of the literature. The purpose of the wedges is to preserve patency of the communication between the syrinx cavity and the expanded subarachnoid space by preventing healing of the myelotomy edges and by maintaining an artificial conduit between the syrinx cavity and the subarachnoid space. Although short-term results are promising, continued long-term follow up is needed to determine the ultimate success of the silastic wedge shunting procedure.

  1. Three-dimensional wedge filling in ordered and disordered systems

    Energy Technology Data Exchange (ETDEWEB)

    Greenall, M J [Department of Mathematics, Imperial College London, 180 Queen' s Gate, London SW7 2BZ (United Kingdom); Parry, A O [Department of Mathematics, Imperial College London, 180 Queen' s Gate, London SW7 2BZ (United Kingdom); Romero-Enrique, J M [Department of Mathematics, Imperial College London, 180 Queen' s Gate, London SW7 2BZ (United Kingdom)

    2004-04-21

    We investigate interfacial structural and fluctuation effects occurring at continuous filling transitions in 3D wedge geometries. We show that fluctuation-induced wedge covariance relations that have been reported recently for 2D filling and wetting have mean-field or classical analogues that apply to higher-dimensional systems. Classical wedge covariance emerges from analysis of filling in shallow wedges based on a simple interfacial Hamiltonian model and is supported by detailed numerical investigations of filling within a more microscopic Landau-like density functional theory. Evidence is presented that classical wedge covariance is also obeyed for filling in more acute wedges in the asymptotic critical regime. For sufficiently short-ranged forces mean-field predictions for the filling critical exponents and covariance are destroyed by pseudo-one-dimensional interfacial fluctuations. We argue that in this filling fluctuation regime the critical exponents describing the divergence of length scales are related to values of the interfacial wandering exponent {zeta}(d) defined for planar interfaces in (bulk) two-dimensional (d = 2) and three-dimensional (d = 3) systems. For the interfacial height l{sub w} {approx} {theta}-{alpha}){sup -{beta}}{sub w}, with {theta} the contact angle and {alpha} the wedge tilt angle, we find {beta}{sub w} = {zeta}(2)/2(1-{zeta}(3)). For pure systems (thermal disorder) we recover the known result {beta}{sub w} = 1/4 predicted by interfacial Hamiltonian studies whilst for random-bond disorder we predict the universal critical exponent {beta} {approx} even in the presence of dispersion forces. We revisit the transfer matrix theory of three-dimensional filling based on an effective interfacial Hamiltonian model and discuss the interplay between breather, tilt and torsional interfacial fluctuations. We show that the coupling of the modes allows the problem to be mapped onto a quantum mechanical problem as conjectured by previous authors

  2. Non-linear critical taper model and determination of accretionary wedge strength

    Science.gov (United States)

    Yang, Che-Ming; Dong, Jia-Jyun; Hsieh, Yuan-Lung; Liu, Hsueh-Hua; Liu, Cheng-Lung

    2016-12-01

    The critical taper model has been widely used to evaluate the strength contrast between the wedge and the basal detachment of fold-and-thrust belts and accretionary wedges. However, determination of the strength parameters using the traditional critical taper model, which adopts the Mohr-Coulomb failure criterion, is difficult, if not impossible. In this study, we propose a modified critical taper model that incorporates the non-linear Hoek-Brown failure criterion. The parameters in the proposed critical Hoek-Brown wedge CHBW model can be directly evaluated via field investigations and laboratory tests. Meanwhile, the wedge strength is a function of the wedge thickness, which is oriented from stress non-linearity. The fold-and-thrust belt in western central Taiwan was used as an example to validate the proposed model. The determined wedge strength was 0.86 using a representative wedge thickness of 5.3 km; this was close to the inferred value of 0.6 from the critical taper. Interestingly, a concave topographic relief is predicted as a result of the wedge thickness dependency of the wedge strength, even if the wedge is composed of homogeneous materials and if the strength of the detachment is uniform. This study demonstrates that the influence of wedge strength on the critical taper angle can be quantified by the spatial distribution of strength variables and by the consideration of the wedge thickness dependency of wedge strength.

  3. Domains and domain loss

    DEFF Research Database (Denmark)

    Haberland, Hartmut

    2005-01-01

    The domain concept, originally suggested by Schmidt-Rohr in the 1930’s (as credited in Fishman’s writings in the 1970s), was an attempt to sort out different areas of language use in multilingual societies, which are relevant for language choice. In Fishman’s version, domains were considered...... not described in terms of domains, and recent research e.g. about the multilingual communities in the Danish-German border area seems to confirm this....

  4. locally fabricated metal step wedge for quality assurance in ...

    African Journals Online (AJOL)

    DR. AMINU

    materials, as well as to investigate an alternative wedge material. The values of the ... The use of low performance x-ray machines. b. ... machine in the Radiology Department of. JUTH is .... the x-ray beam, while ms determines the interaction.

  5. Stark effect in a wedge-shaped quantum box

    CERN Document Server

    Reyes-Esqueda, J A; Castillo-Mussot, M; Vazquez, G J; Reyes-Esqueda, Jorge-Alejandro; Mendoza, Carlos I.; Castillo-Mussot, Marcelo del; Vazquez, Gerardo J.

    2005-01-01

    The effect of an external applied electric field on the electronic ground state energy of a quantum box with a geometry defined by a wedge is studied by carrying out a variational calculation. This geometry could be used as an approximation for a tip of a cantilever of an atomic force microscope. We study theoretically the Stark effect as function of the parameters of the wedge: its diameter, angular aperture and thickness; as well as function of the intensity of the external electric field applied along the axis of the wedge in both directions; pushing the carrier towards the wider or the narrower parts. A confining electronic effect, which is sharper as the wedge dimensions are smaller, is clearly observed for the first case. Besides, the sign of the Stark shift changes when the angular aperture is changed from small angles to angles theta>pi. For the opposite field, the electronic confinement for large diameters is very small and it is also observed that the Stark shift is almost independent with respect t...

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

    DEFF Research Database (Denmark)

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

    2016-01-01

    : Forced expiratory volume in 1 s (FEV1) ≥60 % of expected, FEV1/forced vital capacity ≥70 %, tumour diameter ≤2 cm, distance from tumour to visceral pleura ≤3 cm, ≤2 separate wedges, no air leak on an intraoperative air leakage test and absence of severe adhesions, bullous/emphysematous disease, pleural...

  7. Wedges, Cones, Cosmic Strings, and the Reality of Vacuum Energy

    CERN Document Server

    Fulling, S A; Truong, P N; Wagner, J

    2012-01-01

    One of J. Stuart Dowker's most significant achievements has been to observe that the theory of diffraction by wedges developed a century ago by Sommerfeld and others provided the key to solving two problems of great interest in general-relativistic quantum field theory during the last quarter of the twentieth century: the vacuum energy associated with an infinitely thin, straight cosmic string, and (after an interchange of time with a space coordinate) the apparent vacuum energy of empty space as viewed by an accelerating observer. In a sense the string problem is more elementary than the wedge, since Sommerfeld's technique was to relate the wedge problem to that of a conical manifold by the method of images. Indeed, Minkowski space, as well as all cone and wedge problems, are related by images to an infinitely sheeted master manifold, which we call Dowker space. We review the research in this area and exhibit in detail the vacuum expectation values of the energy density and pressure of a scalar field in Dowk...

  8. Discrete dislocation plasticity analysis of the wedge indentation of films

    NARCIS (Netherlands)

    Balint, D. S.; Deshpande, V. S.; Needleman, A.; Van der Giessen, E.

    2006-01-01

    The plane strain indentation of single crystal films on a rigid substrate by a rigid wedge indenter is analyzed using discrete dislocation plasticity. The crystals have three slip systems at +/- 35.3 degrees and 90 degrees with respect to the indentation direction. The analyses are carried out for

  9. 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 .

  10. Magnetic and structural instabilities of ultrathin Fe(100) wedges

    Energy Technology Data Exchange (ETDEWEB)

    Bader, S.D.; Li, Dongqi; Qiu, Z.Q.

    1994-05-01

    An overview is provided of recent efforts to explore magnetic and related structural issues for ultrathin Fe films grown epitaxially as wedge structures onto Ag(100) and Cu(100). Experiments were carried out utilizing the surface magneto-optic Kerr effect (SMOKE). Ordinary bcc Fe is lattice-matched to the primitive unit cell of the Ag(100) surface. Fe wedges on Ag(100) can be fabricated whose thick end has in-plane magnetic easy axes due to the shape anisotropy, and whose thin end has perpendicular easy axes due to the surface magnetic anisotrophy. A spin-reorientation transition can thus be studied in the center of the wedge where the competing anisotropies cancel. The goal is to test the Mermin-Wagner theorem which states that long-range order is lost at finite temperatures in an isotropic two-dimensional Heisenberg system. Fe wedges on Cu(100) can be studied in like manner, but the lattice matching permits fcc and tetragonally-distorted fcc phases to provide structural complexity in addition to the interplay of competing magnetic anisotropies. The results of these studies are new phase identifications that help both to put previous work into perspective and to define issues to pursue in the future.

  11. De un modelo bidimensional a un modelo tridimensional de justicia: el replanteamiento teórico feminista de Nancy Fraser

    Directory of Open Access Journals (Sweden)

    María Nohemí González

    2015-10-01

    Full Text Available Este artículo recoge de manera sistemática la propuesta de Nancy Fraser en torno al ideal de justicia y su aplicación en las identidades colectivas. Para ello, se aborda el dilema entre redistribución y reconocimiento, y la tendencia actual del predominio del reconocimiento y el límite de la propuesta bidimensional del pensamiento de Fraser. Finalmente, se reseña el conjunto de nuevas reflexiones abordadas por la autora en su texto Escalas de justicia, en el que la filósofa amplía su modelo, presentandouna tercera dimensión: la representación como una categoría para explicar las injusticias que se producen en el plano político. AbstractThis article gathers in a systematic way the Nancy Fraser’s thinking about her proposal around the justice ideal and its implementation in collective identities. To that end, we deal with the dilemma between redistribution and recognition, and the current trend of recognition predominance. The current article briefly explains the limit of the two-dimensional proposal of Fraser’. Finally we frame the group of new re-fiections which are tackled by her author in her text Escalas de justicia, where the philosopher makes the widening of her model by presenting a third dimension: the representation as a category to explain unfairness produced in the political level.

  12. Wedges, cones, cosmic strings and their vacuum energy

    Science.gov (United States)

    Fulling, S. A.; Trendafilova, C. S.; Truong, P. N.; Wagner, J.

    2012-09-01

    One of J Stuart Dowker’s most significant achievements has been to observe that the theory of diffraction by wedges developed a century ago by Sommerfeld and others provided the key to solving two problems of great interest in general-relativistic quantum field theory during the last quarter of the 20th century: the vacuum energy associated with an infinitely thin, straight cosmic string, and (after an interchange of time with a space coordinate) the apparent vacuum energy of empty space as viewed by an accelerating observer. In a sense the string problem is more elementary than the wedge, since Sommerfeld’s technique was to relate the wedge problem to that of a conical manifold by the method of images. Indeed, Minkowski space, as well as all cone and wedge problems, are related by images to an infinitely sheeted master manifold, which we call Dowker space. We review the research in this area and exhibit in detail the vacuum expectation values of the energy density and pressure of a scalar field in Dowker space and the cone and wedge spaces that result from it. We point out that the (vanishing) vacuum energy of Minkowski space results, from the point of view of Dowker space, from the quantization of angular modes, in precisely the way that the Casimir energy of a toroidal closed universe results from the quantization of Fourier modes; we hope that this understanding dispels any lingering doubts about the reality of cosmological vacuum energy. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical in honour of Stuart Dowker’s 75th birthday devoted to ‘Applications of zeta functions and other spectral functions in mathematics and physics’.

  13. Vertebral Osteotomies in Ankylosing Spondylitis-Comparison of Outcomes Following Closing Wedge Osteotomy versus Opening Wedge Osteotomy: A Systematic Review.

    Science.gov (United States)

    Ravinsky, Robert A; Ouellet, Jean-Albert; Brodt, Erika D; Dettori, Joseph R

    2013-04-01

    Study Design Systematic review. Study Rationale To seek out and assess the best quality evidence available comparing opening wedge osteotomy (OWO) and closing wedge osteotomy (CWO) in patients with ankylosing spondylitis to determine whether their results differ with regard to several different subjective and objective outcome measures. Objective The aim of this study is to determine whether there is a difference in subjective and objective outcomes when comparing CWO and OWO in patients with ankylosing spondylitis suffering from clinically significant thoracolumbar kyphosis with respect to quality-of-life assessments, complication risks, and the amount of correction of the spine achieved at follow-up. Methods A systematic review was undertaken of articles published up to July 2012. Electronic databases and reference lists of key articles were searched to identify studies comparing effectiveness and safety outcomes between adult patients with ankylosing spondylitis who received closing wedge versus opening wedge osteotomies. Studies that included pediatric patients, polysegmental osteotomies, or revision procedures were excluded. Two independent reviewers assessed the strength of evidence using the GRADE criteria and disagreements were resolved by consensus. Results From a total of 67 possible citations, 4 retrospective cohorts (class of evidence III) met our inclusion criteria and form the basis for this report. No differences in Oswestry Disability Index, visual analog scale for pain, Scoliosis Research Society (SRS)-24 score, SRS-22 score, and patient satisfaction were reported between the closing and opening wedge groups across two studies. Regarding radiological outcomes following closing versus opening osteotomies, mean change in sagittal vertical axis ranged from 8.9 to 10.8 cm and 8.0 to 10.9 cm, respectively, across three studies; mean change in lumbar lordosis ranged from 36 to 47 degrees and 19 to 41 degrees across four studies; and mean change

  14. Comparison of clinical and radiological outcomes between opening-wedge and closing-wedge high tibial osteotomy: A comprehensive meta-analysis

    Science.gov (United States)

    Wu, Lingfeng; Lin, Jun; Jin, Zhicheng; Cai, Xiaobin; Gao, Weiyang

    2017-01-01

    High tibial osteotomy (HTO) has been widely used for clinical treatment of osteoarthritis of the medial compartment of the knee, and both opening-wedge and closing-wedge HTO are the most commonly used methods. However, it remains unclear which technique has better clinical and radiological outcomes in practice. To systematically evaluate this issue, we conducted a comprehensive meta-analysis by pooling all available data for the opening-wedge HTO and closing-wedge HTO techniques from the electronic databases including PubMed, Embase, Wed of Science and Cochrane Library. A total of 22 studies encompassing 2582 cases were finally enrolled in the meta-analysis. There was no significant difference regarding surgery time, duration of hospitalization, knee pain VAS, Lysholm score and HSS knee score (clinical outcomes) between the opening-wedge and closing-wedge HTO groups (P > 0.05). However, the opening-wedge HTO group showed wider range of motion than the closing-wedge HTO group (P = 0.003). Moreover, as for Hip-Knee-Ankle angle and mean angle of correction, no significant difference was observed between the opening-wedge and closing-wedge HTO groups (P > 0.05), while the opening-wedge HTO group showed greater posterior tibial slope angle (P < 0.001) and lesser patellar height than the closing-wedge HTO group (P < 0.001). On light of the above analysis, we believe that individualized surgical approach should be introduced based on the clinical characteristics of each patient. PMID:28182736

  15. New machining and testing method of large angle infrared wedge mirror parts

    Science.gov (United States)

    Su, Ying; Guo, Rui; Zhang, Fumei; Zhang, Zheng; Liu, Xuanmin; Zengqi, Xu; Li, Wenting; Zhang, Feng

    2016-10-01

    Large angle wedge parts were widely used in the optical system that was used for achieving a wide range of scanning. Due to the parts having the characteristic of large difference in the thickness of both ends and high density, the accuracy of the wedge angle was hard to ensure to reach second level in optical processing. Generally, wedge mirror angle was measured by contact comparison method which was easy to damage the surface. In view of the existence of two practical problems, in this paper, based on theoretical analysis, by taking three key measures that were the accurate positioning for the central position of the large angle wedge part, the accuracy control of angle precision machined of wedge mirror and fast and non destructive laser assisted absolute measurement of large angle wedge, the qualified rate of parts were increased to 100%, a feasible, controllable and efficient process route for large angle infrared wedge parts was found out.

  16. Electrodynamic Casimir Effect in a Medium-Filled Wedge II

    CERN Document Server

    Ellingsen, Simen Adnoy; Milton, Kimball A

    2009-01-01

    We consider the Casimir energy in a geometry of an infinite magnetodielectric wedge closed by a circularly cylindrical arc embedded in another magnetodielectric medium, under the condition that the speed of light be the same in both media. An expression for the Casimir energy corresponding to the arc is obtained and it is found that in the limit where the reflectivity of the boundaries tends to unity the finite part of the Casimir energy of a perfectly conducting wedge-shaped sheet closed by a circular cylinder is regained. The energy of the latter geometry possesses divergences due to the presence of sharp corners. We argue how this is a pathology of the assumption of ideal conductor boundaries, and that no analogous term enters in the present geometry.

  17. MHD Casson nanofluid flow past a wedge with Newtonian heating

    Science.gov (United States)

    Ahmad, Kartini; Hanouf, Zahir; Ishak, Anuar

    2017-02-01

    The problem of steady Casson nanofluid flow past a wedge is studied in this paper. The presence of magnetic field along with Newtonian heating at the surface is considered. The governing partial differential equations are first transformed into a set of nonlinear ordinary differential equations by similarity transformations, before being solved numerically using the Keller-box method. The effects of the wedge angle Ω from 0° (horizontal plate) to 180° (vertical plate) as well as of as the magnetic parameter M on the non-Newtonian fluid flow and heat transfer characteristics are investigated. It is found that the surface temperature is slightly higher for the flow over a horizontal plate compared to that over a vertical plate. It is also found that the magnetic field decreases the surface temperature but increases the skin friction. The flow of a Newtonian fluid is found to give higher skin friction as compared to that of Casson fluid.

  18. 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...

  19. Wedge Splitting Test and Fracture Energy on Particulate Reinforced Composites

    Energy Technology Data Exchange (ETDEWEB)

    Na, Seong Hyeon; Kim, Jae Hoon; Choi, Hoon Seok [Chungnam National Univ., Daejeon (Korea, Republic of); Park, Jae Beom; Kim, Shin Hoe; Jung, Gyoo Dong [Agency for Defense Developmen, Daejeon (Korea, Republic of)

    2016-03-15

    The effect of temperature on the fracture energy, crack propagation, and crack tip opening displacement(CTOD) was determined for particulate reinforced composites using the wedge splitting test. The materials that were used consisted of a polymer binder, an oxidizing agent, and aluminum particles. The test rate of the wedge splitting specimen was 50 mm/min, the temperature conditions were 50℃, room temperature, -40℃, and -60℃. The fracture energy, calculated from splitting load-crack mouth opening displacement(CMOD) curves, increased with decreasing temperature from 50℃ to -40℃. In addition, the strength of the particulate reinforced composites increased sharply at -60℃, and the composites evidenced brittle fracture due to the glass transition temperature. The strain fields near the crack tip were analyzed using digital image correlation.

  20. Modal Analysis in Lined Wedge-Shaped Ducts

    Science.gov (United States)

    Mechel, F. P.

    1998-10-01

    It has been suggested to describe the sound field in a wedge-shaped duct in a cylindrical co-ordinate system in which the boundaries of the wedge lie in a co-ordinate surface. This suggestion was developed in a companion paper [1]. The wave equation can be separated only if the boundaries are ideally reflecting (rigid or soft). Two solutions were proposed in reference [1] for absorbing boundaries. In the first solution the sound field is composed of “ideal modes” (modes in a wedge with ideally reflecting boundaries); the boundary condition at the absorbing boundary then leads to a system of equations for the mode amplitudes. The problem with this method lies in the fact that there is no radial orthogonality of the ideal modes so that the precision of the field synthesis by ideal modes is doubtful. In the second method in reference [1] one defines “fictitious modes” which satisfy the boundary conditions at the flanks exactly and which are based on hypergeometric functions as radial functions, but which produce a “rest” in the wave equation. It was described how this rest can be minimized; this procedure leads to slow numerical integrations. In the present paper, the wedge is subdivided into duct sections with parallel walls (the boundary is stepped); the fields in the sections are composed of duct modes (modes in a straight lined duct); the mode amplitudes are determined from the boundary conditions at the section limits. The advantages of the present method are (analytically) the duct modes are orthogonal across the sections, so the mode amplitudes can be determined with the usual precision of a modal analysis, and (numerically) no numerical integrations are needed.

  1. 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.

  2. 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).

  3. DNS of compressible turbulent boundary layer over a blunt wedge

    Institute of Scientific and Technical Information of China (English)

    LI Xinliang; FU Dexun; MA Yanwan

    2005-01-01

    Direct numerical simulation of spatially evolving compressible boundary layer over a blunt wedge is performed in this paper. The free-stream Mach number is 6 and the disturbance source produced by wall blowing and suction is located downstream of the sound-speed point. Statistics are studied and compared with the results in incompressible flat-plate boundary layer. The mean pressure gradient effects on the vortex structure are studied.

  4. Water-saturated physical modeling of accretionary wedges

    Science.gov (United States)

    Yamada, Y.; Zhang, M.; Nakajima, H.; Driss, E.

    2005-12-01

    Accretionary wedges have been an important research target from view points of earthquake mechanism at the subduction zone, sediment deformation that is closely coupled with hydrology, and resource exploration such as methane hydrates. The knowledge obtained from the study may also be useful for site selection of geological disposal of hazardous materials including radioactive nuclear wastes, in coastal areas of tectonically unstable island arc systems like Japan. The wedges have been well-investigated with analogue models in particular sandbox experiments that typically use dry granular materials, thus the inter-granular pore space of the sandbox experiments is filled with air. In natural sediments, however, the pore space is filled with formation water and its pressure has special effects on structural development. In order to accurately simulate the in-situ conditions and to examine the effects of water on the deformation process of accretionary wedge, a new apparatus was recently constructed in AIST, Japan, to perform physical analog experiments of accretionary wedges under water-saturated condition. For comparisons, equivalent experiments with dry materials were also conducted. The physical properties of the materials were also measured with tri-axial compression tests to interpret the experimental observations. Preliminary results obtained from this study showed that the fundamental parameters on structural geometry, such as taper angle and fault spacing, can be correlated well in wet and dry experiments. These are also in good agreement with physical properties obtained by the tri-axial compression tests, suggesting that the internal friction coefficient decreases as the overburden pressure increases. In the under water models, buoyancy decreases apparent grain density and overburden pressure thus the internal friction coefficient also decreases. This also agrees with the structural geometry of the experimental results. These results suggest that under

  5. Opening- and Closing-Wedge Distal Femoral Osteotomy

    Science.gov (United States)

    Chahla, Jorge; Mitchell, Justin J.; Liechti, Daniel J.; Moatshe, Gilbert; Menge, Travis J.; Dean, Chase S.; LaPrade, Robert F.

    2016-01-01

    Background: Lateral compartment osteoarthritis of the knee can be a challenging pathology in the younger, active population due to limited treatment options and high patient expectations. Distal femoral osteotomy (DFO) has been reported to be a potential treatment option. Purpose: To perform a systematic review on the survival, outcomes, and complications of DFO for treatment of genu valgum with concomitant lateral compartment osteoarthritis of the knee. Study Design: Systematic review; Level of evidence, 4. Methods: A systematic review of the literature was performed using the Cochrane Database of Systematic Reviews, the Cochrane Central Registry of Controlled Trials, PubMed, and MEDLINE from 1980 to present. Inclusion criteria were as follows: outcomes of opening- and closing-wedge DFOs performed for treatment of genu valgum with concomitant lateral compartment osteoarthritis of the knee, English language, minimum 2-year follow-up, and human studies. Data abstracted from the selected studies included type of osteotomy (opening vs closing), survival rate, patient-reported and radiographic outcomes, and complications. Results: Fourteen studies met the inclusion criteria and were considered for the review. A total of 9 closing-wedge and 5 opening-wedge DFO studies were included. All were retrospective studies and reported good to excellent patient-reported outcomes after DFO. Survival decreased with increasing time from surgery, with 1 study reporting a 100% survival rate at 6.5 years, compared with 21.5% at 20 years in another study. A low rate of complications was reported throughout the review. Conclusion: Highly heterogeneous literature exists for both opening- and closing-wedge DFOs for the treatment of isolated lateral compartment osteoarthritis with valgus malalignment. A mean survival rate of 80% at 10-year follow-up was reported, supporting that this procedure can be a viable treatment option to delay or reduce the need for joint arthroplasty. A low

  6. Wedge-local quantum fields on a nonconstant noncommutative spacetime

    Energy Technology Data Exchange (ETDEWEB)

    Much, A. [Max-Planck-Institute for Mathematics in the Sciences, 04103 Leipzig (Germany) and Institute for Theoretical Physics, University of Leipzig, 04009 Leipzig (Germany)

    2012-08-15

    Within the framework of warped convolutions we deform the massless free scalar field. The deformation is performed by using the generators of the special conformal transformations. The investigation shows that the deformed field turns out to be wedge-local. Furthermore, it is shown that the spacetime induced by the deformation with the special conformal operators is nonconstant noncommutative. The noncommutativity is obtained by calculating the deformed commutator of the coordinates.

  7. 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.

  8. Wave dynamic processes in cellular detonation reflection from wedges

    Institute of Scientific and Technical Information of China (English)

    Zongmin Hu; Zonglin Jiang

    2007-01-01

    When the cell width of the incident deto-nation wave (IDW) is comparable to or larger than theMach stem height,self-similarity will fail during IDWreflection from a wedge surface.In this paper,the det-onation reflection from wedges is investigated for thewave dynamic processes occurring in the wave front,including transverse shock motion and detonation cellvariations behind the Mach stem.A detailed reactionmodel is implemented to simulate two-dimensional cel-lular detonations in stoichiometric mixtures of H2/O2diluted by Argon.The numerical results show that thetransverse waves,which cross the triple point trajec-tory of Mach reflection,travel along the Mach stem andreflect back from the wedge surface,control the size ofthe cells in the region swept by the Mach stem.It is theenergy carried by these transverse waves that sustainsthe triple-wave-collision with a higher frequency withinthe over-driven Mach stem.In some cases,local wavedynamic processes and wave structures play a dominantrole in determining the pattern of cellular record,lead-ing to the fact that the cellular patterns after the Machstem exhibit some peculiar modes.

  9. 一种基于BEMD的纹理图像分类改进方法%An improved texture image classification method based on bidimensional empirical mode decomposition

    Institute of Scientific and Technical Information of China (English)

    赵春晖; 周振国

    2012-01-01

    An improved texture image classification method based on bidimensional empirical mode decomposition is proposed. Firstly, the texture image is decomposed to two bidimensional Intrinsic Mode Function (IMF) and one residue by using BEMD algorithm, and then five texture feature parameters are extracted from each of the two IMF combined with Gray Level Co-occurrence Matrix, by which an extended ten dimensional feature vector is formed. Finally, texture image classification is done using minimum distance classifier according to the extended feature vector. Simulation results verified the effectiveness of the method for texture image classification.%提出了一种基于二维经验模式分解( BEMD)的纹理图像分类改进方法.采用BEMD算法将纹理图像分解为两层二维固有模态函数(IMF)和一个余量之和,结合灰度共生矩阵(GLCM)对这两层IMF各提取5个纹理特征参数,组成一个扩展的10维特征向量,然后根据扩展的特征向量,采用最小距离分类器( MDC)进行纹理图像分类.仿真结果证明了该方法进行纹理图像分类的有效性.

  10. Bidimensional illustration touches in children books: consideration about their construction in the context of the education of children with visual impairments

    Directory of Open Access Journals (Sweden)

    Adriano Henrique Nuernberg

    2010-06-01

    Full Text Available The politics diffusion of the inclusive education last decade was positive for the several initiatives that wanted to promote the access to the knowledge from visual deficiency people. Many of these initiatives, however, have their theories from crooked notions about the ways of access and concepts elaborated of blind people, mainly when it deals with the congenital blindness. The goal of this article is to discuss the construction of bidimensional illustration touches as a way of guarantee the access of the visual content from children books. Based in the historic-cultural psychology from Vigotski, differences are pointed between the ways of visual and touch perception, taking the language as a way of blindness social compensation. Finding conceptual problems of the construction of these bidimensional illustration touches, it is a hope to collaborate for the improvement of the quality of the material produced in the context of the inclusive education, having in view the attention to the different topics of the psychical human being in the presence of the congenital blindness.

  11. Robustness of oscillatory α2 dynamos in spherical wedges

    Science.gov (United States)

    Cole, E.; Brandenburg, A.; Käpylä, P. J.; Käpylä, M. J.

    2016-10-01

    Context. Large-scale dynamo simulations are sometimes confined to spherical wedge geometries by imposing artificial boundary conditions at high latitudes. This may lead to spatio-temporal behaviours that are not representative of those in full spherical shells. Aims: We study the connection between spherical wedge and full spherical shell geometries using simple mean-field dynamos. Methods: We solve the equations for one-dimensional time-dependent α2 and α2Ω mean-field dynamos with only latitudinal extent to examine the effects of varying the polar angle θ0 between the latitudinal boundaries and the poles in spherical coordinates. Results: In the case of constant α and ηt profiles, we find oscillatory solutions only with the commonly used perfect conductor boundary condition in a wedge geometry, while for full spheres all boundary conditions produce stationary solutions, indicating that perfect conductor conditions lead to unphysical solutions in such a wedge setup. To search for configurations in which this problem can be alleviated we choose a profile of the turbulent magnetic diffusivity that decreases toward the poles, corresponding to high conductivity there. Oscillatory solutions are now achieved with models extending to the poles, but the magnetic field is strongly concentrated near the poles and the oscillation period is very long. By changing both the turbulent magnetic diffusivity and α profiles so that both effects are more concentrated toward the equator, we see oscillatory dynamos with equatorward drift, shorter cycles, and magnetic fields distributed over a wider range of latitudes. Those profiles thus remove the sensitive and unphysical dependence on θ0. When introducing radial shear, we again see oscillatory dynamos, and the direction of drift follows the Parker-Yoshimura rule. Conclusions: A reduced α effect near the poles with a turbulent diffusivity concentrated toward the equator yields oscillatory dynamos with equatorward migration and

  12. 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...

  13. Assessment of computerized treatment planning system accuracy in calculating wedge factors of physical wedged fields for 6 MV photon beams.

    Science.gov (United States)

    Muhammad, Wazir; Maqbool, Muhammad; Shahid, Muhammad; Hussain, Amjad; Tahir, Sajjad; Matiullah; Rooh, Gul; Ahmad, Tanveer; Lee, Sang Hoon

    2011-07-01

    Wedge filters are commonly used in external beam radiotherapy to achieve a uniform dose distribution within the target volume. The main objective of this study was to investigate the accuracy of the beam modifier algorithm of Theraplan plus (TPP version 3.8) treatment planning system and to confirm that either the beam hardening, beam softening and attenuation coefficients along with wedge geometry and measured wedge factor at single depth and multiple fields sizes can be the replacement of wedged profile and wedged cross-sectional data or not. In this regard the effect of beam hardening and beam softening was studied with physical wedges for 6 MV photons. The Normalized Wedge Factors (NWFs) were measured experimentally as well as calculated with the Theraplan plus, as a function of depth and field size in a water phantom for 15°, 30°, 45°, and 60° wedge filters. The beam hardening and softening was determined experimentally by deriving the required coefficients for all wedge angles. The TPP version 3.8 requires wedge transmission factor at single depth and multiple field sizes. Without incorporating the hardening and softening coefficients the percent difference between measured and calculated NFWs was as high as 7%. After the introduction of these parameters into the algorithm, the agreement between measured and TPP (V 3.8) calculated NWFs were improved to within 2 percent for various depths. Similar improvement was observed in TPP version 3.8 while calculating NWFs for various field sizes when the required coefficients were adjusted. In conclusion, the dose calculation algorithm of TPP version 3.8 showed good accuracy for a 6 MV photon beam provided beam hardening and softening parameters are taken into account. From the results, it is also concluded that, the beam hardening, beam softening and attenuation coefficients along with wedge geometry and measured wedge factor at single depth and multiple fields sizes can be the replacement of wedged profile and

  14. Observation of wedge waves and their mode transformation by laser ultrasonic technique

    Institute of Scientific and Technical Information of China (English)

    Jing Jia; Zhonghua Shen; Lijuan Wang; Ling Yuan

    2011-01-01

    Wedge waves (WWs) in wedges, including their dispersion characteristics and mode transformation, are investigated using the laser ultrasound technique. Pulsed laser excitation and optical deflection beam method for detection are used to record WWs. Numerous WWs are detected by scanning the excitation laser along the wedge tip. Dispersions of WWs are obtained by using the two-dimensional (2D) Fourier transformation method, and different WW orders are revealed on the wedges. Mode transformation is determined by fixing the distance between the excitation and detection position, as well as by scanning the samples along the normal direction of the wedge tip.%@@ Wedge waves (WWs) in wedges, including their dispersion characteristics and mode transformation, are investigated using the laser ultrasound technique. Pulsed laser excitation and optical deflection beam method for detection are used to record WWs. Numerous WWs are detected by scanning the excitation laser along the wedge tip. Dispersions of WWs are obtained by using the two-dimensional (2D) Fourier transformation method, and different WW orders are revealed on the wedges. Mode transformation is determined by fixing the distance between the excitation and detection position, as well as by scanning the samples along the normal direction of the wedge tip.

  15. 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

    2016-07-01

    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.

  16. 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.

  17. Modes of continental extension in a crustal wedge

    Science.gov (United States)

    Wu, Guangliang; Lavier, Luc L.; Choi, Eunseo

    2015-07-01

    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.

  18. 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.

  19. 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...

  20. 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

  1. Inverse analysis of the wedge-splitting test

    DEFF Research Database (Denmark)

    Skocek, Jan; Stang, Henrik

    2008-01-01

    The amount of information which it is possible to retrieve from the wedge-splitting test is investigated. Inverse analysis is undertaken based on the analytical hinge model for various multi-linear softening curves. This showed that the commonly used bi-linear softening curve can be replaced...... by an tip to quad-linear curve, which is reflected by increased accuracy of the test simulation. Furthermore it was demonstrated that the next refinement of the softening curve leads to convergence problems due to problems with local minima. Finally, the semi-analytically obtained results are verified using...

  2. Electric monopoles in generalised B\\wedge F theories

    CERN Document Server

    Temple-Raston, M

    1996-01-01

    A tensor product generalisation of B\\wedge F theories is proposed to give a Bogomol'nyi structure. Non-singular, stable, finite-energy particle-like solutions to the Bogomol'nyi equations are studied. Unlike Yang-Mills(-Higgs) theory, the Bogomol'nyi structure does not appear as a perfect square in the Lagrangian. Consequently, the Bogomol'nyi energy can be obtained in more than one way. The added flexibility permits electric monopole solutions to the field equations.

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

    DEFF Research Database (Denmark)

    Mølgaard, Carsten; Kersting, Uwe G.

    -dimensional gait analysis. Barefoot walking, walking in a running shoe, an Oxford-type leather shoe, and a rocker shoe were analyzed. The shoes were tested both with and without a 10-degree full length laterally wedged insole. Results: Similar, significant reductions in the peak knee adduction moment with lateral...... 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...

  4. Modified retro-tubercle opening-wedge versus conventional high tibial osteotomy.

    Science.gov (United States)

    Keyhani, Sohrab; Abbasian, Mohammad Reza; Kazemi, Seyed Morteza; Esmailiejah, Ali Akbar; Seyed Hosseinzadeh, Hamid Reza; Shahi, Alisina; Shahi, Ali Sina; Firouzi, Farzad

    2011-01-01

    Despite the fact that common surgical techniques for the treatment of genu varum usually correct the malalignment in the affected knee, these methods have significant complications and cause problems in the long term. Retro-tubercle opening-wedge high tibial osteotomy is among the newer techniques for the treatment of genu varum. The goal of this study was to compare the results of retro-tubercle opening-wedge high tibial osteotomy with those of medial opening-wedge osteotomy. In a randomized, controlled trial, 72 patients with varus knees who were scheduled for surgery were assigned into either the retro-tubercle opening-wedge high tibial osteotomy (n=34) or medial opening-wedge osteotomy groups (n=38). Groups were matched for age and sex. The position of the patella was compared with respect to the tuberosity and the upper tibial slope pre- and postoperatively. Patients were followed for an average of 13 months (range, 10-21 months). In the retro-tubercle opening-wedge high tibial osteotomy group, the length of the patellar tendon did not significantly differ pre- and postoperatively (P≥.5); however, in the medial opening-wedge osteotomy group, a statistically significant shortening was noted in patellar tendon postoperatively (P≤.05). Similarly, the tibial plateau inclination showed a statistically significant difference postoperatively in the medial opening-wedge osteotomy group, while the difference in the retro-tubercle opening-wedge high tibial osteotomy group did not reach statistical significance.

  5. 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

    . Using scanning near-field optical imaging at the wavelengths in the range of 1.43 - 1.52 µm, we demonstrate low-loss (propagation length ~ 120 µm) and well-confined (mode width ≅ 1.3 µm) wedge plasmon-polariton guiding along triangular 6-µm-high and 70.5°- angle gold wedges. Experimental observations......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...

  6. 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

  7. Imágenes en cardiopatía congénita en el adulto: Ecocardiografía: De la imagen bidimensional a la imagen en cuatro dimensiones

    OpenAIRE

    Erdmenger Orellana,Julio

    2006-01-01

    En la presente publicación se hace un análisis de la utilidad de la ecocardiografía, y sus diferentes modalidades, en el diagnóstico de pacientes adultos portadores de CC. Se pone especial énfasis en el análisis desde la vista bidimensional hasta la vista en cuatro dimensiones.

  8. Domain analysis

    DEFF Research Database (Denmark)

    Hjørland, Birger

    2017-01-01

    The domain-analytic approach to knowledge organization (KO) (and to the broader field of library and information science, LIS) is outlined. The article reviews the discussions and proposals on the definition of domains, and provides an example of a domain-analytic study in the field of art studie....... Varieties of domain analysis as well as criticism and controversies are presented and discussed....

  9. Los recursos tecnológicos en la estadística bidimensional en los textos españoles de bachillerato

    OpenAIRE

    Gea,María M.; Carmen Batanero; María del Mar López-Martín; José Miguel Contreras

    2015-01-01

    Los currículos actuales recomiendan el uso de los recursos tecnológicos en la enseñanza de la estadística, por la ventaja que suponen en el cálculo y representación gráfica, el trabajo con datos reales y el aprendizaje de conceptos a través de la simulación. En esta investigación se analizan los recursos tecnológicos que los libros de texto sugieren para la enseñanza y aprendizaje de la estadística bidimensional en bachillerato (organización y representación de datos bidimensionales, correlac...

  10. Dying Flow Bursts as Generators of the Substorm Current Wedge

    Science.gov (United States)

    Haerendel, Gerhard

    2016-07-01

    Many theories or conjectures exist on the driver of the substorm current wedge, e.g. rerouting of the tail current, current disruption, flow braking, vortex formation, and current sheet collapse. Magnitude, spatial scale, and temporal development of the related magnetic perturbations suggest that the generator is related to the interaction of the flow bursts with the dipolar magnetosphere after onset of reconnection in the near-Earth tail. The question remains whether it is the flow energy that feeds the wedge current or the internal energy of the arriving plasma. In this presentation I argue for the latter. The current generation is attributed to the force exerted by the dipolarized magnetic field of the flow bursts on the preceding layer of high-beta plasma after flow braking. The generator current is the grad-B current at the outer boundary of the compressed high-beta plasma layers. It needs the sequential arrival of several flow bursts to account for duration and magnitude of the ionospheric closure current.

  11. Growth and mixing dynamics of mantle wedge plumes

    Science.gov (United States)

    Gorczyk, Weronika; Gerya, Taras V.; Connolly, James A. D.; Yuen, David A.

    2007-07-01

    Recent work suggests that hydrated partially molten thermal-chemical plumes that originate from subducted slab as a consequence of Rayleigh-Taylor instability are responsible for the heterogeneous composition of the mantle wedge. We use a two-dimensional ultrahigh-resolution numerical simulation involving 10 × 109 active markers to anticipate the detailed evolution of the internal structure of natural plumes beneath volcanic arcs in intraoceanic subduction settings. The plumes consist of partially molten hydrated peridotite, dry solid mantle, and subducted oceanic crust, which may compose as much as 12% of the plume. As plumes grow and mature these materials mix chaotically, resulting in attenuation and duplication of the original layering on scales of 1-1000 m. Comparison of numerical results with geological observations from the Horoman ultramafic complex in Japan suggests that mixing and differentiation processes related to development of partially molten plumes above slabs may be responsible for the strongly layered lithologically mixed (marble cake) structure of asthenospheric mantle wedges.

  12. Relation of the auroral substorm to the substorm current wedge

    Science.gov (United States)

    McPherron, Robert L.; Chu, Xiangning

    2016-12-01

    The auroral substorm is an organized sequence of events seen in the aurora near midnight. It is a manifestation of the magnetospheric substorm which is a disturbance of the magnetosphere brought about by the solar wind transfer of magnetic flux from the dayside to the tail lobes and its return through the plasma sheet to the dayside. The most dramatic feature of the auroral substorm is the sudden brightening and poleward expansion of the aurora. Intimately associated with this expansion is a westward electrical current flowing across the bulge of expanding aurora. This current is fed by a downward field-aligned current (FAC) at its eastern edge and an upward current at its western edge. This current system is called the substorm current wedge (SCW). The SCW forms within a minute of auroral expansion. FAC are created by pressure gradients and field line bending from shears in plasma flow. Both of these are the result of pileup and diversion of plasma flows in the near-earth plasma sheet. The origins of these flows are reconnection sites further back in the tail. The auroral expansion can be explained by a combination of a change in field line mapping caused by the substorm current wedge and a tailward growth of the outer edge of the pileup region. We illustrate this scenario with a complex substorm and discuss some of the problems associated with this interpretation.

  13. An automated optical wedge calibrator for Dobson ozone spectrophotometers

    Science.gov (United States)

    Evans, R. D.; Komhyr, W. D.; Grass, R. D.

    1994-01-01

    The Dobson ozone spectrophotometer measures the difference of intensity between selected wavelengths in the ultraviolet. The method uses an optical attenuator (the 'Wedge') in this measurement. The knowledge of the relationship of the wedge position to the attenuation is critical to the correct calculation of ozone from the measurement. The procedure to determine this relationship is time-consuming, and requires a highly skilled person to perform it correctly. The relationship has been found to change with time. For reliable ozone values, the procedure should be done on a Dobson instrument at regular intervals. Due to the skill and time necessary to perform this procedure, many instruments have gone as long as 15 years between procedures. This article describes an apparatus that performs the procedure under computer control, and is adaptable to the majority of existing Dobson instruments. Part of the apparatus is usable for normal operation of the Dobson instrument, and would allow computer collection of the data and real-time ozone measurements.

  14. IMPLEMENTACIÓN DE UNA METODOLOGÍA PARA LA SEPARACIÓN DE PROTEOMAS DE PLASMA HUMANO MEDIANTE ELECTROFORESIS BIDIMENSIONAL

    Directory of Open Access Journals (Sweden)

    Ruth Andrea Rodríguez

    2015-09-01

    Full Text Available El análisis proteómico en derivados sanguíneos es una importante herramienta en el descubrimiento de biomarcadores para el diagnóstico de enfermedades, aunque su caracterización exhibe desafíos relacionados con el amplio rango dinámico de las proteínas. En este trabajo se implementaron las condiciones para la separación de proteomas de plasma sanguíneo por electroforesis bidimensional. En muestras de plasma de infante y adulto se evaluaron dos sistemas de pretratamiento de la muestra para reducir el rango dinámico de las proteínas: inmunodepleción de proteínas abundantes y enriquecimiento de proteínas de baja abundancia. Los proteomas se separaron por electroforesis bidimensional y las imágenes se analizaron con el programa Melanie 7.0. Se encontró que ambos métodos de pretratamiento fueron reproducibles y permitieron ver las diferencias en los proteomas de infante y adulto, como muestran los análisis de componentes principales y de clasificación jerárquica tipo heatmap. El porcentaje de recuperación de proteínas fue mayor con la inmunodepleción en comparación con el enriquecimiento proteico. Estos resultados permitieron concluir que con la inmunodepleción, se tiene mayor control de las proteínas eliminadas y por tanto menor pérdida de información, lo que permite su aplicación en estudios exploratorios para la identificación de potenciales biomarcadores de enfermedad.

  15. Duality in nonlinear B$\\wedge$F models equivalence between self-dual and topologically massive Born-Infeld B$\\wedge$F models

    CERN Document Server

    Menezes, R; Ribeiro, R F; Wotzasek, C

    2002-01-01

    We study the dual equivalence between the nonlinear generalization of the self-dual ($NSD_{B\\wedge F}$) and the topologically massive $B\\wedge F$ models with particular emphasis on the nonlinear electrodynamics proposed by Born and Infeld. This is done through a dynamical gauge embedding of the nonlinear self-dual model yielding to a gauge invariant and dynamically equivalent theory. We clearly show that nonpolinomial $NSD_{B\\wedge F}$ models can be mapped, through a properly defined duality transformation, into $TM_{B\\wedge F}$ actions. The general result obtained is then particularized for a number of examples, including the Born-Infeld-BF (BIBF) model that has experienced a revival in the recent literature.

  16. Spatial and temporal distribution of deformation at the front of the Andean orogenic wedge in Bolivia and implications for incremental wedge evolution

    Science.gov (United States)

    Weiss, J. R.; Brooks, B. A.; Vergani, G.; Arrowsmith, R.

    2012-12-01

    There is no consensus regarding how orogenic wedges accommodate deformation over seismo-tectonic timescales. Results from the Himalaya and Taiwan suggest differing mechanisms including localized deformation along a single wedge-front structure and distributed shortening across multiple structures respectively. Here we provide the first detailed constraints on the distribution and timing of deformation at the front of the Andean orogenic wedge using industry acquired seismic reflection data from the ~500-km-long thin-skinned fold-and-thrust belt of the Bolivian Subandes (BSA). Almost no information exists on the recent history of BSA wedge-front deformation despite the presence of multiple ~10-m-high topographic scarps on Holocene surfaces and a recent analysis of the GPS-derived velocity field, which suggests the frontal Mandeyapecua thrust fault system (MTFS) is capable of >Mw 8 earthquakes. We use stratigraphic relationships across fault-related folds to depict the onset of deformation for the complete suite of structures comprising the MTFS. For each structure we determine the uncertainty in timing using an envelope of seismic velocity models from ~70 well-logs and published Quaternary sedimentation rates for the region. We further explore fault geometry and fault slip parameters associated with the displacement field of seismic reflection horizons using elastic dislocation theory. Our analyses reveal the presence of at least eight distinct fault segments comprising the MTFS, including previously unrecognized subsurface thrust faults that have been active since ~1 Ma. Shortening rates are generally higher across the younger, northern portion of the fault system but across-strike, in a ~50-km-wide zone from west to east, no distinct pattern of deformation migration exists. We estimate the percentage of whole-wedge deformation accommodated by wedge-front structures using our new fault slip rates combined with the wedge-loading rate of ~10 mm/yr and place our

  17. First direct dating of Late Pleistocene ice-wedges by AMS

    NARCIS (Netherlands)

    Vasil'chuk, YK; van der Plicht, J; Jungner, H; Sonninen, E; Vasil'chuk, AC; Vasil'chuk, Yurij K.; Vasil'chuk, Alla C.

    2000-01-01

    We present the first direct dating by C-14-accelerator mass spectrometry of three Late Pleistocene syngenetic ice-wedges from the Seyaha cross-section. They are representative of permafrost with multistage ice-wedges from the North of Western Siberia. The most important result is the clear vertical

  18. Revisit the classical Newmark displacement method for earthquake-induced wedge slide

    Science.gov (United States)

    Yang, Che-Ming; Cheng, Hui-Yun; Wu, Wen-Jie; Hsu, Chang-Hsuan; Dong, Jia-Jyun; Lee, Chyi-Tyi

    2016-04-01

    Newmark displacement method has been widely used to study the earthquake-induced landslides and adopted to explore the initiation and kinematics of catastrophic planar failure in recent years. However, surprisingly few researchers utilize the Newmark displacement method to study the earthquake-induced wedge slide. The classical Newmark displacement method for earthquake-induced wedge sliding assumed the wedge is rigid and the vertical acceleration, as well as the horizontal acceleration perpendicular to the sliding direction, is neglected. Moreover, the friction coefficients on the weak planes are assumed as unchanged during sliding. The purpose of this study is to test the reasonableness of the aforementioned assumptions. This study uses Newmark displacement method incorporating the rigid wedge method (RWM) and maximum shear stress method (MSSM) to evaluate the influence of wedge deformation. We design the geometry of the wedge and input the synthetic seismicity to trigger the wedge slide. The influence for neglecting the vertical and horizontal (perpendicular to the sliding direction) accelerations is also assessed. Besides, this research incorporates the velocity-displacement dependent friction law in the analysis to evaluate the influence of constant friction coefficient assumption. Result of this study illustrated that the aforementioned assumptions have significant effects on the calculated permeant displacement, moving speed, and failure initiation. To conclude, this study provides new insights on the initiation and kinematics of an earthquake induced wedge slide.

  19. Enhancement of linear and second-order hyperpolarizabilities in wedge-shaped nanostructures

    Science.gov (United States)

    Jayabalan, J.; Singh, Manoranjan P.; Rustagi, K. C.

    2003-08-01

    Analytical solutions for the wave functions for free electrons inside a wedge-shaped quantum dot are reported. For silver wedge-shaped quantum dots, linear and second-order hyperpolarizabilities are calculated for various apex angles. It is found that linear and nonlinear hyperpolarizabilities both increase with decreasing apex angle.

  20. Duwamish Waterways Navigation Improvement Study: Analysis of Impacts on Water Quality and Salt Wedge Characteristics.

    Science.gov (United States)

    1981-02-01

    dissolved oxygen consumption in the saltwater wedge is emphasized. A section has also been prepared discussing sediment transport in the estuary...biomass produced and sedimented 23 1,000 800 00 0 400 Xi. . *-*’* 200 ox- :~. ---0 - .....’ ~ ’J FIGURE 6 Annual Dissolved Oxygen Consumption in the wedge

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

    Science.gov (United States)

    Carlone, Raffaele; Posilicano, Andrea

    2017-03-01

    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.

  2. Immediate and 1 week effects of laterally wedge insoles on gait biomechanics in healthy females.

    Science.gov (United States)

    Weinhandl, Joshua T; Sudheimer, Sarah E; Van Lunen, Bonnie L; Stewart, Kimberly; Hoch, Matthew C

    2016-03-01

    It is estimated that approximately 45% of the U.S. population will develop knee osteoarthritis, a disease that creates significant economic burdens in both direct and indirect costs. Laterally wedged insoles have been frequently recommended to reduce knee abduction moments and to manage knee osteoarthritis. However, it remains unknown whether the lateral wedge will reduce knee abduction moments over a prolonged period of time. Thus, the purposes of this study were to (1) examine the immediate effects of a laterally wedged insole in individuals normally aligned knees and (2) determine prolonged effects after the insole was worn for 1 week. Gait analysis was performed on ten women with and without a laterally wedged insole. After participants wore the wedges for a week, a second gait analysis was performed with and without the insole. The wedged insole did not affect peak knee abduction moment, although there was a significant increase in knee abduction angular impulse after wearing the insoles for 1 week. Furthermore, there was a significant increase in vertical ground reaction force at the instance of peak knee abduction moment with the wedges. While the laterally wedged insole used in the current study did not alter knee abduction moments as expected, other studies have shown alterations. Future studies should also examine a longer acclimation period, the influence of gait speed, and the effect of different shoe types with the insole.

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

    Science.gov (United States)

    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.; Walker, Donald A.; Wilson, Cathy J.; Yabuki, Hironori; Zona, Donatella

    2016-04-01

    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 and forms disconnected troughs that hold isolated ponds. Continued ice-wedge melting leads to increased trough connectivity and an overall draining of the landscape. We find that melting at the tops of ice wedges over recent decades and subsequent decimetre-scale ground subsidence is a widespread Arctic phenomenon. Although permafrost temperatures have been increasing gradually, we find that ice-wedge degradation is occurring on sub-decadal timescales. Our hydrological model simulations show that advanced ice-wedge degradation can significantly alter the water balance of lowland tundra by reducing inundation and increasing runoff, in particular due to changes in snow distribution as troughs form. We predict that ice-wedge degradation and the hydrological changes associated with the resulting differential ground subsidence will expand and amplify in rapidly warming permafrost regions.

  4. Comparison of dosimetric characteristics of Siemens virtual and physical wedges for ONCOR linear accelerator

    Directory of Open Access Journals (Sweden)

    Attalla Ehab

    2010-01-01

    Full Text Available Dosimetric properties of virtual wedge (VW and physical wedge (PW in 6- and 10-MV photon beams from a Siemens ONCOR linear accelerator, including wedge factors, depth doses, dose profiles, peripheral doses, are compared. While there is a great difference in absolute values of wedge factors, VW factors (VWFs and PW factors (PWFs have a similar trend as a function of field size. PWFs have stronger depth dependence than VWF due to beam hardening in PW fields. VW dose profiles in the wedge direction, in general, match very well with those of PW, except in the toe area of large wedge angles with large field sizes. Dose profiles in the nonwedge direction show a significant reduction in PW fields due to off-axis beam softening and oblique filtration. PW fields have significantly higher peripheral doses than open and VW fields. VW fields have similar surface doses as the open fields, while PW fields have lower surface doses. Surface doses for both VW and PW increase with field size and slightly with wedge angle. For VW fields with wedge angles 45° and less, the initial gap up to 3 cm is dosimetrically acceptable when compared to dose profiles of PW. VW fields in general use less monitor units than PW fields.

  5. Investigation of a Wedge Adhesion Test for Edge Seals

    Energy Technology Data Exchange (ETDEWEB)

    Kempe, Michael; Wohlgemuth, John; Miller, David; Postak, Lori; Booth, Dennis; Phillips, Nancy

    2016-09-26

    Many photovoltaic (PV) technologies have been found to be sensitive to moisture that diffuses into a PV package. Even with the use of impermeable frontsheets and backsheets, moisture can penetrate from the edges of a module. To limit this moisture ingress pathway from occurring, manufacturers often use a low permeability polyisobutylene (PIB) based edge seal filled with desiccant to further restrict moisture ingress. Moisture ingress studies have shown that these materials are capable of blocking moisture for the 25-year life of a module; but to do so, they must remain well-adhered and free of cracks. This work focuses on adapting the Boeing Wedge test for use with edge seals laminated using glass substrates as part of a strategy to assess the long-term durability of edge seals. The advantage of this method is that it duplicates the residual stresses and strains that a glass/glass module may have when the lamination process results in some residual glass bending that puts the perimeter in tension. Additionally, this method allows one to simultaneously expose the material to thermal stress, humidity, mechanical stress, and ultraviolet radiation. The disadvantage of this method generally is that we are limited by the fracture toughness of the glass substrates that the edge seal is adhered to. However, the low toughness of typical uncrosslinked or sparsely crosslinked PIB makes them suitable for this technique. We present data obtained during the development of the wedge test for use with PV edge seal materials. This includes development of the measuring techniques and evaluation of the test method with relevant materials. We find consistent data within a given experiment, along with the theoretical independence of fracture toughness measurements with wedge thickness. This indicates that the test methodology is reproducible. However, even though individual experimental sets are consistent, the reproducibility between experimental sets is poor. We believe this may be

  6. Investigation of a wedge adhesion test for edge seals

    Science.gov (United States)

    Kempe, Michael; Wohlgemuth, John; Miller, David; Postak, Lori; Booth, Dennis; Phillips, Nancy

    2016-09-01

    Many photovoltaic (PV) technologies have been found to be sensitive to moisture that diffuses into a PV package. Even with the use of impermeable frontsheets and backsheets, moisture can penetrate from the edges of a module. To limit this moisture ingress pathway from occurring, manufacturers often use a low permeability polyisobutylene (PIB) based edge seal filled with desiccant to further restrict moisture ingress. Moisture ingress studies have shown that these materials are capable of blocking moisture for the 25-year life of a module; but to do so, they must remain well-adhered and free of cracks. This work focuses on adapting the Boeing Wedge test for use with edge seals laminated using glass substrates as part of a strategy to assess the long-term durability of edge seals. The advantage of this method is that it duplicates the residual stresses and strains that a glass/glass module may have when the lamination process results in some residual glass bending that puts the perimeter in tension. Additionally, this method allows one to simultaneously expose the material to thermal stress, humidity, mechanical stress, and ultraviolet radiation. The disadvantage of this method generally is that we are limited by the fracture toughness of the glass substrates that the edge seal is adhered to. However, the low toughness of typical uncrosslinked or sparsely crosslinked PIB makes them suitable for this technique. We present data obtained during the development of the wedge test for use with PV edge seal materials. This includes development of the measuring techniques and evaluation of the test method with relevant materials. We find consistent data within a given experiment, along with the theoretical independence of fracture toughness measurements with wedge thickness. This indicates that the test methodology is reproducible. However, even though individual experimental sets are consistent, the reproducibility between experimental sets is poor. We believe this may be

  7. Late Jurassic blueschist facies pebbles from the Western Carpathian orogenic wedge and paleostructural implications for Western Tethys evolution

    Science.gov (United States)

    Dal Piaz, Giorgio V.; Martin, Silvana; Villa, Igor M.; Gosso, Guido; Marschalko, Robert

    1995-08-01

    In spite of the absence of ophiolitic slices at the surface, some traces of the lost Tethys ocean are recorded along the Pieniny Klippen Belt (PKB), a narrow décollement thrust system sutured at the transpressive boundary between the Outer and Inner Carpathians. The enigmatic precollisional evolution of Western Carpathians can be deciphered from some late Albian to Campanian flysch conglomerates which display chrome spinel grains, ophiolitic detritus and pebbles of blueschist facies tholeiitic metabasalts yielding a 40Ar/39Ar plateau age of 155.4+/-0.6 Ma. Other detrital components are represented by extrabasinal pebbles of limestones, arc volcanics, and igneous to metamorphic basement rocks from southern sources. Our results suggest a markedly northward extension of the sublongitudinal Triassic Vardar (Meliata) Ocean and its subduction since the late Middle Jurassic, supposedly balanced westward by coeval spreading in the Ligurian-Piedmont basin of the Apennine-Western Alpine Tethys. A lateral kinematic connection between these diachronous and roughly parallel Tethys branches was provided on the north by a left-lateral east-west trending shear zone running from the Swiss-Austrian Penninic domain to the Northern Carpathians. This reconstruction replaces the classic model of two paired North Penninic and South Penninic oceanic basins and eastern homologues with the Briançonnais-Hochstegen and Czorstin microcontinents in between. The Late Jurassic-Early Cretaceous evolution of the Carpathian active margin was characterized by subduction metamorphism and accretion of a wide orogenic wedge; in this time, the shallowing to deeply subsiding basins inferred from facies analyses on the sedimentary units of the PKB were likely floored by individual sections of the growing wedge. Later, some exhuming blueschist ophiolitic units of the wedge were uplifted to the surface and functioned in the Albian-Campanian as an ``exotic ridge'' supplying clasts to the forearc basin

  8. 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

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

    DEFF Research Database (Denmark)

    Mølgaard, Carsten; Kersting, Uwe G.

    The increasing number of patients with developing osteoarthritis is accompanied by a growing scientific interest in non-operative early treatment strategies. It is generally believed that laterally wedged insoles can change the distribution of the knee loading, but the importance of footwear design......-dimensional gait analysis. Barefoot walking, walking in a running shoe, an Oxford-type leather shoe, and a rocker shoe were analyzed. The shoes were tested both with and without a 10-degree full length laterally wedged insole. Results: Similar, significant reductions in the peak knee adduction moment with lateral...... 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...

  10. Bonding mechanism of ultrasonic wedge bonding of copper wire on Au/Ni/Cu substrate

    Institute of Scientific and Technical Information of China (English)

    TIAN Yan-hong; WANG Chun-qing; Y. Norman ZHOU

    2008-01-01

    The ultrasonic wedge bonding with d25 μm copper wire was achieved on Au/Ni plated Cu substrate at ambient temperature. Ultrasonic wedge bonding mechanism was investigated by using SEM/EDX, pull test, shear test and microhardness test. The results show that the thinning of the Au layer occurs directly below the center of the bonding tool with the bonding power increasing. The interdiffusion between copper wire and Au metallization during the wedge bonding is assumed negligible, and the wedge bonding is achieved by wear action induced by ultrasonic vibration. The ultrasonic power contributes to enhance the deformation of copper wire due to ultrasonic softening effect which is then followed by the strain hardening of the copper wedge bonding.

  11. 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.

  12. Isolating active orogenic wedge deformation in the southern Subandes of Bolivia

    Science.gov (United States)

    Weiss, Jonathan R.; Brooks, Benjamin A.; Foster, James H.; Bevis, Michael; Echalar, Arturo; Caccamise, Dana; Heck, Jacob; Kendrick, Eric; Ahlgren, Kevin; Raleigh, David; Smalley, Robert; Vergani, Gustavo

    2016-08-01

    A new GPS-derived surface velocity field for the central Andean backarc permits an assessment of orogenic wedge deformation across the southern Subandes of Bolivia, where recent studies suggest that great earthquakes (>Mw 8) are possible. We find that the backarc is not isolated from the main plate boundary seismic cycle. Rather, signals from subduction zone earthquakes contaminate the velocity field at distances greater than 800 km from the Chile trench. Two new wedge-crossing velocity profiles, corrected for seasonal and earthquake affects, reveal distinct regions that reflect (1) locking of the main plate boundary across the high Andes, (2) the location of and loading rate at the back of orogenic wedge, and (3) an east flank velocity gradient indicative of décollement locking beneath the Subandes. Modeling of the Subandean portions of the profiles indicates along-strike variations in the décollement locked width (WL) and wedge loading rate; the northern wedge décollement has a WL of ~100 km while accumulating slip at a rate of ~14 mm/yr, whereas the southern wedge has a WL of ~61 km and a slip rate of ~7 mm/yr. When compared to Quaternary estimates of geologic shortening and evidence for Holocene internal wedge deformation, the new GPS-derived wedge loading rates may indicate that the southern wedge is experiencing a phase of thickening via reactivation of preexisting internal structures. In contrast, we suspect that the northern wedge is undergoing an accretion or widening phase primarily via slip on relatively young thrust-front faults.

  13. The use of sternal wedge osteotomy in pectus surgery: when is it necessary?

    Science.gov (United States)

    Kara, Murat; Gundogdu, Ahmet Gokhan; Kadioglu, Salih Zeki; Cayirci, Ertug Can; Taskin, Necati

    2016-09-01

    The Ravitch procedure is a well-established surgical procedure for correction of chest wall deformities. Sternal wedge osteotomy is an important part of this procedure. We studied the incidence of wedge osteotomy with respect to the type of chest wall deformity in patients undergoing surgical correction with the use of a recently developed chest wall stabilization system. A total of 47 patients, 39 (83%) male and 8 (17%) female with a mean age of 14.9 ± 2.1 years, underwent the Ravitch procedure. Twenty-four (51.1%) had pectus carinatum, 19 (40.4%) had pectus excavatum, and 4 (8.5%) had pectus arcuatum. A conventional or oblique sternal wedge osteotomy was performed as indicated, followed by chest wall stabilization using the MedXpert system. Of the 47 patients, 27 (57.4%) had a sternal wedge osteotomy. All cases of pectus arcuatum and redo cases underwent sternal wedge osteotomy. Pectus excavatum cases tended to have a greater incidence of wedge osteotomy compared to pectus carinatum cases (68.4% vs. 41.7%, p = 0.052). Patients with more resected ribs had a greater rate of wedge osteotomy (63.4%) compared to those with fewer resected ribs (16.7%, p = 0.043). A sternal wedge osteotomy is more commonly performed in patients with pectus excavatum compared to those with pectus carinatum. All redo and pectus arcuatum cases need a wedge osteotomy for proper correction. Wedge osteotomy is very likely in more aggressive corrections with more rib resections. © The Author(s) 2016.

  14. 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

  15. 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

  16. WEIGHTED KOPPELMAN-LERAY-NORGUET FORMULAS ON A LOCAL q-CONCAVE WEDGE IN A COMPLEX MANIFOLD

    Institute of Scientific and Technical Information of China (English)

    邱春晖; 姚宗元

    2003-01-01

    A weighted Koppelman-Leray-Norguet formula of (r, s) differential forms ona local q-concave wedge in a complex manifold is obtained. By constructing the newweighted kernels, the authors give a new weighted Koppelman-Leray-Norguet formula with-out boundary integral of (r, s) differential forms, which is different from the classical one.The new weighted formula is especially suitable for the case of the local q-concave wedgewith a non-smooth boundary, so one can avoid complex estimates of boundary integralsand the density of integral may be not defined on the boundary but only in the domain.Moreover, the weighted integral formulas have much freedom in applications such as in theinterpolation of functions.

  17. Verification of Varian Enhanced Dynamic Wedge implementation in masterplan treatment planning system.

    Science.gov (United States)

    Pasquino, Massimo; Casanova Borca, Valeria; Tofani, Santi; Ozzello, Franca

    2009-04-22

    This paper investigates the accuracy of the two available calculation algorithms of the Oncentra MasterPlan three-dimensional treatment planning system (TPS)-- the pencil beam method and collapsed-cone convolution--in modeling the Varian enhanced dynamic wedge (EDW). Measurements were carried out for a dual high energy (6-15 MV) Varian DHX-S linear accelerator using ionization chambers for beam axis measurements (wedge factors and depth doses), film dosimetry for off-axis dose profiles measurements, and a diode matrix detector for two dimensional absolute dose distributions. Using both calculation algorithms, different configuration of symmetric and asymmetric fields varying the wedge's angle were tested. Accuracy of the treatment planning system was evaluated in terms of percentage differences between measured and calculated values for wedge factors, depth doses, and profiles. As far as the absolute dose distribution was concerned, the gamma index method (Low et al.) was used with 3% and 3 mm as acceptance criteria for dose difference and distance-to-agreement, respectively. Wedge factors and percentage depth doses were within 1% deviation between calculated and measured values. The comparison of measured and calculated dose profiles shows that the Van Dyk's acceptance criteria (Van Dyk et al.) are generally met; a disagreement can be noted for large wedge angles and field size limited to the low dose-low gradient region only. The 2D absolute dose distribution analysis confirms the good accuracy of the two calculation algorithms in modeling the enhanced dynamic wedge.

  18. Biomechanical effects of lateral and medial wedge insoles on unilateral weight bearing.

    Science.gov (United States)

    Sawada, Tomonori; Kito, Nobuhiro; Yukimune, Masaki; Tokuda, Kazuki; Tanimoto, Kenji; Anan, Masaya; Takahashi, Makoto; Shinkoda, Koichi

    2016-01-01

    [Purpose] Lateral wedge insoles reduce the peak external knee adduction moment and are advocated for patients with knee osteoarthritis. However, some patients demonstrate adverse biomechanical effects with treatment. In this study, we examined the immediate effects of lateral and medial wedge insoles under unilateral weight bearing. [Subjects and Methods] Thirty healthy young adults participated in this study. The subjects were assessed by using the foot posture index, and were divided into three groups: normal foot, pronated foot, and supinated foot groups. The knee adduction moment and knee-ground reaction force lever arm under the studied conditions were measured by using a three-dimensional motion capture system and force plates. [Results] In the normal and pronated groups, the change in knee adduction moment significantly decreased under the lateral wedge insole condition compared with the medial wedge insole condition. In the normal group, the change in the knee-ground reaction force lever arm also significantly decreased under the lateral wedge insole condition than under the medial wedge insole condition. [Conclusion] Lateral wedge insoles significantly reduced the knee adduction moment and knee-ground reaction force lever arm during unilateral weight bearing in subjects with normal feet, and the biomechanical effects varied according to individual foot alignment.

  19. Measured Two-Dimensional Ice-Wedge Polygon Thermal Dynamics

    Science.gov (United States)

    Cable, William; Romanovsky, Vladimir; Busey, Robert

    2016-04-01

    Ice-wedge polygons are perhaps the most dominant permafrost related features in the arctic landscape. The microtopography of these features, that includes rims, troughs, and high and low polygon centers, alters the local hydrology, as water tends to collect in the low areas. During winter, wind redistribution of snow leads to an increased snowpack depth in the low areas, while the slightly higher areas often have very thin snow cover, leading to differences across the landscape in vegetation communities and soil moisture between higher and lower areas. These differences in local surface conditions lead to spatial variability of the ground thermal regime in the different microtopographic areas and between different types of ice-wedge polygons. To study these features in depth, we established temperature transects across four different types of ice-wedge polygons near Barrow, Alaska. The transects were composed of five vertical array thermistor probes (VATP) beginning in the center of each polygon and extending through the trough to the rim of the adjacent polygon. Each VATP had 16 thermistors from the surface to a depth of 1.5 m. In addition to these 80 subsurface temperature measurement points per polygon, soil moisture, thermal conductivity, heat flux, and snow depth were all measured in multiple locations for each polygon. Above ground, a full suite of micrometeorological instrumentation was present at each polygon. Data from these sites has been collected continuously for the last three years. We found snow cover, timing and depth, and active layer soil moisture to be major controlling factors in the observed thermal regimes. In troughs and in the centers of low-center polygons, the combined effect of typically saturated soils and increased snow accumulation resulted in the highest mean annual ground temperatures (MAGT). Additionally, these areas were the last part of the polygon to refreeze during the winter. However, increased active layer thickness was not

  20. Metastable olivine wedge beneath northeast China and its applications

    Science.gov (United States)

    Jiang, G.; Zhao, D.; Zhang, G.

    2013-12-01

    When the Pacific slab subducted into the mantle transition zone, there might exist a metastable olivine wedge (MOW) inside the slab due to the phase transition. Lots of researchers have adopted such various methods to detect the characteristics of this MOW as the forward modeling of travel times, shear wave amplitude patterns, teleseismic P wave coda, receiver function imaging, thermodynamic simulation and so on. Almost all results could be more or less affected by the source, the receiver and/or the velocity model passed through by the seismic rays. In this study, we have used 21 deep earthquakes, greater than 400 km and locating beneath northeast China, to study the velocity within the MOW. For more precisions, we have done further modifications in two ways based on our previous studies. (1) Double-difference location method is used to relocate all events with an error of 1-2 km with the data recorded by stations both at northeast China and at Japan. All relocated events locate in a zone about 30 km away from the upper boundary of Pacific slab. (2) Double residual travel times, generated by an event-pair at a common station at only Japan, are used to constrain the velocity anomaly rather than the residuals themselves. As a result, we have found that an ultra-lower velocity zone (ULVZ), averagely -7% relative to the iasp91 model, exists within the subducted Pacific slab around the deep earthquakes, which might be represented as the metastable olivine wedge. Because of the lower-velocity corresponding to the lower-density, the MOW would provide upward buoyancy forces which might prevent the slab from free subduction into the mantle transition zone. This feed-back mechanism of MOW to the slab is called ';parachute-effect', which is characterized by other researchers. In addition, the existence of the ULVZ or the MOW in the slab may supply a possible mechanism for triggering deep earthquakes, called ';phase transformation faulting', which was already proposed few

  1. 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.

  2. Line-of-Sight Observables Algorithms for the Helioseismic and Magnetic Imager (HMI) Instrument Tested with Interferometric Bidimensional Spectrometer (IBIS) Observations

    Science.gov (United States)

    Couvidat, Sébastien; Rajaguru, S. P.; Wachter, Richard; Sankarasubramanian, K.; Schou, Jesper; Scherrer, Philip H.

    2012-05-01

    The Helioseismic and Magnetic Imager (HMI) instrument onboard the Solar Dynamics Observatory produces line-of-sight (LOS) observables (Doppler velocity, magnetic-field strength, Fe i line width, line depth, and continuum intensity) as well as vector magnetic-field maps at the solar surface. The accuracy of LOS observables is dependent on the algorithm used to translate a sequence of HMI filtergrams into the corresponding observables. Using one hour of high-cadence imaging spectropolarimetric observations of a sunspot in the Fe i line at 6173 Å through the Interferometric Bidimensional Spectrometer installed at the Dunn Solar Telescope, and the Milne-Eddington inversion of the corresponding Stokes vectors, we test the accuracy of the observables algorithm currently implemented in the HMI data-analysis pipeline: the MDI-like algorithm. In an attempt to improve the accuracy of HMI observables, we also compare this algorithm to others that may be implemented in the future: a least-squares fit with a Gaussian profile, a least-squares fit with a Voigt profile, and the use of second Fourier coefficients in the MDI-like algorithm.

  3. One-way successive plate cross wedge rolling machine

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    In our last paper(Sci China Ser E-Tech Sci,2009,52(11):3117-3121) we designed the precision forming machine with rolling plate CWR(cross wedge rolling).This kind of machine colligates the advantages of high rigidity and small floor space for roller CWR machine and those of simple die manufacture and high precision for plate CWR machine.At the same time,it abandons the shortcomings of complex die manufacture and poor precision for roller CWR machine,and those of poor rigidity and large floor space for plate CWR machine.During rolling,the upper and lower rolling plates of the machine make reciprocating slide toward or away from each other,so the inertial forces should be overcome,which will cause great energy loss,besides,large floor space is needed when the rolled workpiece is large.In order to solve the above problems,this paper presents the one-way successive plate CWR machine,whose rolling plates need not make reciprocating slide.Hence,it has high energy utilization efficiency and production efficiency.Furthermore,the roll scale can be removed automatically.In particular,the machine can produce large axisymmetrical workpieces.

  4. Sinking, wedging, spreading - viscous spreading on a layer of fluid

    Science.gov (United States)

    Bergemann, Nico; Juel, Anne; Heil, Matthias

    2016-11-01

    We study the axisymmetric spreading of a sessile drop on a pre-existing layer of the same fluid in a regime where the drop is sufficiently large so that the spreading is driven by gravity while capillary and inertial effects are negligible. Experiments performed with 5 ml drops and layer thicknesses in the range 0.1 mm drop evolves as R tn , where the spreading exponent n increases with the layer thickness h. Numerical simulations, based on the axisymmetric free-surface Navier-Stokes equations, reveal three distinct spreading regimes depending on the layer thickness. For thick layers the drop sinks into the layer, accompanied by significant flow in the layer. By contrast, for thin layers the layer ahead of the propagating front is at rest and the spreading behaviour resembles that of a gravity-driven drop spreading on a dry substrate. In the intermediate regime the spreading is characterised by an advancing wedge, which is sustained by fluid flow from the drop into the layer.

  5. 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.

  6. Lateral closed wedge osteotomy for cubitus varus deformity

    Directory of Open Access Journals (Sweden)

    Srivastava Amit

    2008-01-01

    Full Text Available Background: Lateral closed wedge (LCW osteotomy is a commonly accepted method for the correction of the cubitus varus deformity. The fixation of osteotomy is required to prevent loss of correction achieved. The fixation of the osteotomy by the two screw and figure of eight wire is not stable enough to maintain the correction achieved during surgery. In this prospective study we supplemented the fixation by Kirschner′s (K- wires for stable fixation and evaluated the results. Materials and Methods: Twenty-one cases of the cubitus varus deformity following supracondylar fractures of the humerus were operated by LCW osteotomy during February 2001 to June 2006. The mean age of the patients at the time of corrective surgery was 8.5 years (range 6.6-14 years. The osteotomy was fixed by two screws with figure of eight tension band wire between them and the fixation was supplemented by passing two to three K-wires from the lateral condyle engaging the proximal medial cortex through the osteotomy site. Result: The mean follow-up period was 2.5 years (range seven months to 3.4 years. The results were assessed as per Morrey criteria. Eighteen cases showed excellent results and three cases showed good results. Two cases had superficial pin tract infection. Conclusion: The additional fixation by K wires controls rotational forces effectively besides angulation and translation forces and maintains the correction achieved peroperatively.

  7. Precision forming machine with rolling plate cross wedge rolling

    Institute of Scientific and Technical Information of China (English)

    SONG YuQuan; LI ZhiGang; WANG MingHui; GUAN XiaoFang

    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 re-tain 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.

  8. Influence of intermolecular forces at critical-point wedge filling.

    Science.gov (United States)

    Malijevský, Alexandr; Parry, Andrew O

    2016-04-01

    We use microscopic density functional theory to study filling transitions in systems with long-ranged wall-fluid and short-ranged fluid-fluid forces occurring in a right-angle wedge. By changing the strength of the wall-fluid interaction we can induce both wetting and filling transitions over a wide range of temperatures and study the order of these transitions. At low temperatures we find that both wetting and filling transitions are first order in keeping with predictions of simple local effective Hamiltonian models. However close to the bulk critical point the filling transition is observed to be continuous even though the wetting transition remains first order and the wetting binding potential still exhibits a small activation barrier. The critical singularities for adsorption for the continuous filling transitions depend on whether retarded or nonretarded wall-fluid forces are present and are in excellent agreement with predictions of effective Hamiltonian theory even though the change in the order of the transition was not anticipated.

  9. Influence of intermolecular forces at critical-point wedge filling

    Science.gov (United States)

    Malijevský, Alexandr; Parry, Andrew O.

    2016-04-01

    We use microscopic density functional theory to study filling transitions in systems with long-ranged wall-fluid and short-ranged fluid-fluid forces occurring in a right-angle wedge. By changing the strength of the wall-fluid interaction we can induce both wetting and filling transitions over a wide range of temperatures and study the order of these transitions. At low temperatures we find that both wetting and filling transitions are first order in keeping with predictions of simple local effective Hamiltonian models. However close to the bulk critical point the filling transition is observed to be continuous even though the wetting transition remains first order and the wetting binding potential still exhibits a small activation barrier. The critical singularities for adsorption for the continuous filling transitions depend on whether retarded or nonretarded wall-fluid forces are present and are in excellent agreement with predictions of effective Hamiltonian theory even though the change in the order of the transition was not anticipated.

  10. Theoretical basis and significance of the variance of discharge as a bidimensional variable for the design of lateral lines of micro-irrigation Bases teóricas e importância da variância da vazão como variável bidimensional no dimensionamento de linhas laterais em microirrigação

    Directory of Open Access Journals (Sweden)

    Euro Roberto Detomini

    2009-08-01

    Full Text Available In order to support the theoretical basis and contribute to the improvement of educational capability issues relating to irrigation systems design, this point of view presents an alternative deduction of the variance of the discharge as a bidimensional and independent random variable. Then a subsequent brief application of an existing model is applied for statistical design of laterals in micro-irrigation. The better manufacturing precision of emitters allows lengthening a lateral for a given soil slope, although this does not necessarily mean that the statistical uniformity throughout the lateral will be more homogenous.Visando a reforçar as bases teóricas e contribuir com a melhoria da capacitação educacional em assuntos relacionados a dimensionamento de sistemas de irrigação, o presente ponto de vista revela uma dedução alternativa para a variância da vazão dos emissores, variável aleatória independente bidimensional. Posteriormente apresenta breve aplicação do modelo aceito para dimensionamento de linhas laterais em sistemas de microirrigação, de acordo com a abordagem estatística. A melhor precisão na fabricação de emssores permite, para uma dada inclinação de terreno, dimensionar laterais mais longas, o que não significa necessariamente que uniformidade de emissão dessas laterais será projetada como mais homogênea.

  11. Experimental and Numerical Procedures of a Sonar Platform with a Sound Absorption Wedge

    Institute of Scientific and Technical Information of China (English)

    Danzhu Yu; Xiongliang Yao; Shaoshi Dai

    2011-01-01

    Experiments involving a sonar platform with a sound absorption wedge were carried out for the purpose of obtaining the low frequency acoustic characteristics.Acoustic characteristics of a sonar platform model with a sound absorption wedge were measured,and the effects of different wedge laid areas on platform acoustic characteristic were tested.Vibration acceleration and self-noise caused by model vibration were measured in four conditions:0%,36%,60%,and 100% of wedge laid area when the sonar platform was under a single frequency excitation force.An experiment was performed to validate a corresponding numerical calculation.The numerical vibration characteristics of platform area were calculated by the finite element method,and self-noise caused by the vibration in it was predicted by an experiential formula.The conclusions prove that the numerical calculation method can partially replace the experimental process for obtaining vibration and sound characteristics.

  12. Fabrication and Determination of Refractive Index Profile of the Planar Waveguides by Wedge Technique

    Institute of Scientific and Technical Information of China (English)

    S.; M.; R.; Sadat; Hosseini; A.; Darudi

    2003-01-01

    Several planar waveguides have been fabricated. The waveguides have been polished for determination of their refractive index profiles (RIP) by wedge method. The RIP determined by inserting the sample in a Mach-Zehnder interferometer and applying fringe analysis methods.

  13. Fabrication and Determination of Refractive Index Profile of the Planar Waveguides by Wedge Technique

    Institute of Scientific and Technical Information of China (English)

    S. M. R. Sadat Hosseini; A. Darudi

    2003-01-01

    Several planar waveguides have been fabricated. The waveguides have been polished for determination of their refractiveindex profiles (RIP) by wedge method. The RIP determined by inserting the sample in a Mach-Zehnder interferometer andapplying fringe analysis methods.

  14. 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.

  15. Distal femoral varus osteotomy: problems associated with the lateral open-wedge technique.

    Science.gov (United States)

    Jacobi, Matthias; Wahl, Peter; Bouaicha, Samy; Jakob, Roland P; Gautier, Emanuel

    2011-06-01

    Varisation osteotomies on the distal femur are an established treatment method for valgus osteoarthritis of the knee in younger patients. Osteotomy can be done in a lateral open-wedge or medial closed-wedge manner. We retrospectively studied 14 patients treated by the lateral open-wedge technique, fixed with the Tomofix plate, with a mean duration of follow-up of 45 ± 3.4 months. We observed often delayed osteotomy healing after 3, 6 and 12 months, no secondary dislocations, and frequent troublesome irritation due to the plate being on the iliotibial band. However, outcome was satisfactory once the osteotomy healed and the plate was removed. Based on the often slow healing of the osteotomy and frequent irritation due to the plate, this procedure has been abandoned by the authors, and the medial closing-wedge osteotomy adopted as the alternative treatment.

  16. 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.

  17. 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 The diffraction of an inhomogeneous plane wave by an impedance wedge embedded in a lossy medium is analyzed. The rigorous integral representation for the field is asymptotically evaluated in the context of the uniform geometrical theory...

  18. Second-law analysis of fluid flow over an isothermal moving wedge

    Directory of Open Access Journals (Sweden)

    F. Hedayati

    2014-03-01

    Full Text Available In this study, entropy generation minimization (EGM was employed to optimize fluid flow and heat transfer over a moving wedge. Governing partial differential equations including continuity, momentum and energy are reduced to ordinary ones using similarity variables and solved numerically. The novelty of this study is to consider the effects of the moving wedge parameter λ, to find the stable system via entropy generation minimization (EGM method. The results indicated that as the slope of the wedge increases, the absolute values of the optimum moving wedge parameter λo grow as well. Moreover, it was found that the minimum value of entropy generation happens for the negative values of λo which gets smaller as Falkner–Skan power law parameter m increases.

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

    African Journals Online (AJOL)

    International Journal of Engineering, Science and Technology ... Optimization of parameters on material removal rate in micro-WEDG process ... nonconventional machining method for manufacturing accurate and complex three dimensional ...

  20. Study on Mach stems induced by interaction of planar shock waves on two intersecting wedges

    Institute of Scientific and Technical Information of China (English)

    Gaoxiang Xiang; Chun Wang; Honghui Teng; Yang Yang; Zonglin Jiang

    2016-01-01

    The properties of Mach stems in hypersonic corner flow induced by Mach interaction over 3D inter-secting wedges were studied theoretically and numerically. A new method called “spatial dimension reduction” was used to analyze theoretically the location and Mach num-ber behind Mach stems. By using this approach, the problem of 3D steady shock/shock interaction over 3D intersecting wedges was transformed into a 2D moving one on cross sec-tions, which can be solved by shock-polar theory and shock dynamics theory. The properties of Mach interaction over 3D intersecting wedges can be analyzed with the new method, including pressure, temperature, density in the vicinity of triple points, location, and Mach number behind Mach stems. Theoretical results were compared with numerical results, and good agreement was obtained. Also, the influence of Mach number and wedge angle on the properties of a 3D Mach stem was studied.

  1. Comparison of the homogeneity of breast dose distributions with and without the medial wedge.

    Science.gov (United States)

    Ikner, C L; Russo, R; Podgorsak, M B; Proulx, G M; Lee, R J

    1998-01-01

    Radiation of the intact breast often requires medial and lateral wedges to improve dose homogeneity of its pyramidal shape and to achieve acceptable cosmesis. There is some concern that radiation scatter from the medial wedge may contribute to cancer in the uninvolved breast, yet treatment without the medial wedge is associated with inhomogeneity of magnitudes that affect cosmesis. These homogeneities are identified on treatment plans generated at the central axis (CAX). It is not known if comparing isodose curves at the central axis reflect homogeneity in superior and inferior planes. A study was undertaken to both examine inhomogeneity with and without the medial wedge, and to determine if plan selection at the CAX was representative of homogeneity above and below the CAX. Ten consecutive patients with early breast cancers had cranial, CAX, and caudal CT images of each breast compared with two wedging conditions, lateral only (LW) and medial and lateral wedged conditions (dual wedges = DW). Dosimetry was optimized at the CAX for DW and LW conditions. Dose distributions and hot spots relative to prescribed dose were compared for cranial, CAX, and caudal images. Mean chest wall separations were measured. Six of ten patients had equivalent LW and DW distributions at the levels examined. Only one of these patients had a single off-axis hot spot > 20%. Six patients had comparable LW and DW dosimetry and acceptable hot spots at the central axis, as well as chest wall separations < or = 22 cm. In conclusion, if isodose configurations are commensurate at the CAX, these patients will have homogeneity above and below the CAX. In patients with chest wall separations < or = 22 cm, treatment without the medial wedge is feasible, sparing the contralateral breast dose with little compromise to inhomogeneity in the treated breast.

  2. Statics of Magnetic Fluid Drop with Compound Magnetic Core in a Wedge-Shaped Channel

    Directory of Open Access Journals (Sweden)

    V. Bashtovoi

    2013-12-01

    Full Text Available A behavior of magnetic fluid drop with compound magnetic core in a wedge-shaped channel was studied experimentally. The study examines influence of magnetic fluid properties, its volume and magnetic field on statics of the system compound magnet – magnetic fluid drop in wedge-shaped channel. The possibility to change the static conditions of such system by altering magnetic field of the core was observed

  3. The effect of foot orthoses and in-shoe wedges during cycling: a systematic review

    OpenAIRE

    Yeo, Boon K; Bonanno, Daniel R

    2014-01-01

    Background The use of foot orthoses and in-shoe wedges in cycling are largely based on theoretical benefits and anecdotal evidence. This review aimed to systematically collect all published research on this topic, critically evaluate the methods and summarise the findings. Methods Study inclusion criteria were: all empirical studies that evaluated the effects of foot orthoses or in-shoe wedges on cycling; outcome measures that investigated physiological parameters, kinematics and kinetics of ...

  4. Assessment of a multibeam Fizeau wedge interferometer for Doppler wind lidar.

    Science.gov (United States)

    McKay, Jack A

    2002-03-20

    The Fabry-Perot interferometer is the standard instrument for the direct detection Doppler lidar measurement of atmospheric wind speeds. The multibeam Fizeau wedge has some practical advantages over the Fabry-Perot, such as the linear fringe pattern, and is evaluated for this application. The optimal Fizeau must have a resolving power of 10(6) or more. As the multibeam Fizeau wedge is pushed to such high resolving power, the interference fringes of the device become complicated by asymmetry and secondary maxima. A simple condition for the interferometer plate reflectance, optical gap, and wedge angle reveals whether a set of parameters will yield simple, Airy-like fringes or complex Fizeau fringes. Tilting of the Fizeau wedge improves the fringe shape and permits an extension of the regime of Airy-like fringes to higher resolving power. Sufficient resolving power for the wind lidar application is shown to be possible with a large-gap, low-finesse multibeam Fizeau wedge. Liabilities of the multibeam Fizeau wedge in the wind lidar application include a smaller acceptance solid angle and calibration sensitivity to localized deviations of the plates from the ideal.

  5. EFFECT OF SALT WEDGE INTRUSION IN KUSHIRO WETLAND CONSIDERING SEA LEVEL RISE

    Science.gov (United States)

    Nakamoto, Atsushi; Shintani, Tetsuya; Nakayama, Keisuke; Maruya, Yasuyuki; Ishida, Tetsuya; Houmura, Kenichi

    This paper describes the effect of sea-level rise (SLR) on the salt wedge intrusion in terms of ecological system in Kushiro wetland. Kushiro wetland was registered by Ramsar Treaty and the largest wetland in Japan. A previous study demonstrates that the salt wedge intrusion may not affect ecological system of Kushiro wetland, such as loss of freshwater plants along Kushiro River. However, it is revealed that SLR may occur in the end of the 21st century, which enhances the increase in the distance of the salt wedge intrusion along Kushiro River and the loss of endangered species of Kushiro wetland along Kushiro River. This study thus aims to investigate the influence of the salt wedge intrusion on freshwater plants along Kushiro River, and to clarify the salt wedge intrusion when SLR occurs due to climate change. We attempted to investigate the influence of SLR on endangered species along Kyu-Kushiro River in which sea water is likely to intrude up to about 8 km from the river mouth. As results, it is suggested from field observations that salinity may decrease freshwater plants along Kushiro River, and it clarifies the possibility that the salt wedge intrudes Kushiro River due to SLR by using 3D hydrodynamic model, Fantom3D.

  6. Experimental study of slot jet impingement heat transfer on a wedge-shaped surface

    Science.gov (United States)

    Rahimi, Mostafa; Irani, Mohammad

    2012-12-01

    An experimental investigation was conducted to study the convective heat transfer rate from a wedge-shaped surface to a rectangular subsonic air jet impinging onto the apex of the wedge. The jet Reynolds number, nozzle-to-surface distance and the wedge angle were considered as the main parameters. Jet Reynolds number was ranged from 5,000 to 20,000 and two dimensionless nozzle-to-surface distances h/w = 4 and 10 were examined. The apex angle of the wedge ranged from 30° to 180° where the latter case corresponds with that of a flat surface. Velocity profile and turbulence intensity were provided for free jet flow using hot wire anemometer. Local and average Nusselt numbers on the impinged surface are presented for all the configurations. Based on the results presented, the local Nusselt number at the stagnation region increases as the wedge angle is decreased but, it then decreases over the remaining area of the impinged surface. Average Nusselt number over the whole surface is maximum when the wedge angle is 180° (i.e. plane surface) for any jet and nozzle-to-surface configuration.

  7. Improve the transconductance of a graphene field-effect transistor by folding graphene into a wedge

    Science.gov (United States)

    Cao, Guiming; Liu, Weihua; Cao, Meng; Li, Xin; Zhang, Anping; Wang, Xiaoli; Chen, Bangdao

    2016-07-01

    The transport property of a graphene wedge channel is studied theoretically and its leakage current through field emission is estimated when considering the effect of the internal electric field. The transconductance of the graphene transistor is improved from 0.016 to 0.321 μS μm-1 when the graphene is folded into a wedge (with angle of wedge π/6 and radius curvature 2.7 nm at the tip), while the wedge height is much smaller than the space between the top-gate and the channel. The improved transconductance is due to the locally enhanced electric field, which results in a potential well and causes electron accumulation at the wedge tip. The leakage current through field emission J FE shows a super-linear increase with the channel conductive current J DS, where overall the electron supply for the field emission at the wedge tip is improved by the channel bias voltage V DS.

  8. Active Aerothermoelastic Control of Hypersonic Double-wedge Lifting Surface

    Institute of Scientific and Technical Information of China (English)

    Laith K Abbas; Chen Qian; Piergiovanni Marzocca; Gürdal Zafer; Abdalla Mostafa

    2008-01-01

    Designing reentry space vehicles and high-speed aireraft requires special attention to the nonlinear thermoelastic and aerodynamic instability of their structural components. The thermal effects are important since temperature environment brings dramatic influences on the static and dynamic behaviors of flight structures in supersonic/hypersonic regimes and is likely to cause instability, catastrophic failure and oscillations resulting in structural failure due to fatigue. In order to understand the dynamic behaviors of these "hot"structures, a double-wedge lifting surface with combining freeplay and cubic 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 aerodynamic isused to estimate the applied nonlinear unsteady aerodynamic loads. Also considered is the loss of torsiunal stiffness that may be incurredby lifting surfaces subject to axial stresses induced by aerodynamic heating. The aerodynamic heating effects are estimated based on theadiabatic wall temperature due to high speed airstreams. As a recently emerging technology, the active aerothermoelastic control isaimed at providing solutions to a large number of problems involving the aeronautica Faerospace flight vehicle structures. To preventsuch damaging phenomena from occurring, an application of linear and nonlinear active control methods on both flutter boundary andpost-flutter behavior has been fulfilled. In this paper, modeling issues as well as numerical simulation have been presented and pertinent conclusions outlined. It is evidenced that a serious loss of torsional stiffness may induce the dynamic instability; however active controlcan be used to expand the flutter boundary and convert unstable limit cycle oscillations (LCO) into the stable LCO and/or to shift the transition between these two states toward higher flight Mach numbers.

  9. Modes of continental extension in a lithospheric wedge

    Science.gov (United States)

    Wu, G.; Lavier, L. L.; Choi, E.

    2014-12-01

    We studied extension of a lithospheric wedge as an approximation to an orogenic belt or a continental margin. We ran a series of numerical models to quantify the effects of the strength of the lower crust and a mid-crustal shear zone (MCSZ) on the extension processes. When the MCSZ is present, we found that the regional lower crustal flow plays a critical role in controlling the modes of extension. The compensation is long-wavelength when the lower crust flows from the highest to the lowest elevation in order to compensate upper crustal thinning. In response to this motion, the mantle flows towards the highest elevation in order to balance for the lower crust leaving the area under the highest topography. For weak (wet quartz regime with partial melting) or intermediate (wet quartz regime), or strong (dry quartz regime) lower crust, we recognized three predominantly decoupled modes of extension characterized by 1) significant lower crustal exhumation exemplified as a large massif, 2) formation of core complexes and detachment faults, and 3) distributive domino faulting, respectively. Without the MCSZ, however, the lower crustal flow is essentially subdued with predominantly coupled extension. For weak or intermediate, or strong lower crust, we recognized three coupled modes characterized by 1) localized generally symmetric crustal exhumation, 2) distributed grabens and narrow rifts, and 3) wide continental margins, respectively. The MCSZ controls the degree of decoupling of the lower crustal flow such that a frictionally stronger MCSZ does not change the behaviors of the models but results in a more distributed extension. Due to the long-wavelength compensation, subhorizontal Moho is achieved where intensive extension occurred for all the decoupled models with a MCSZ. Natural counterparts for each mode may be easily identified, for instance, in the Basin and Range or the Aegean.

  10. Laboratory investigation of water extraction effects on saltwater wedge displacement

    Directory of Open Access Journals (Sweden)

    S. Noorabadi

    2017-12-01

    Full Text Available There is a close connection between saltwater intrusion into aquifers and groundwater extraction. Freshwater extraction in coastal aquifers is one of the most important reasons for the saltwater intrusion into these aquifers. Condition of extraction system such as well depth, discharge rate, saltwater concentration and etc. could affect this process widely. Thus, investigating different extraction conditions comprises many management advantages.  In the present study, the effects of freshwater extraction on saltwater interface displacement have been investigated in a laboratory box. Three different well depths (H were considered with combinations of 3 different extraction rates (Q and 3 saltwater concentrations (C for detailed investigation of the effects of these factors variations on saltwater displacement. SEAWAT model has been used to simulate all the scenarios to numerically study of the process. The experimental and numerical results showed that when the C and Q rates were small and the well depth was shallow, the saltwater interface wouldn’t reach the extraction well, so the extracted water remained uncontaminated. When the C and Q rates were increased and the well was deepened, the salinity of the extracted water became higher. When the Q and C rates were high enough, in the shallow well depth, the final concentration of the extracted water was low but a huge part of the porous media was contaminated by the saltwater, furthermore when the well was deepened enough, the final concentration of the extracted water was increased but a small part of the porous media was contaminated by the saltwater. Finally, the results showed that when the Q and H rates were high enough, the extraction well behaved like a barrier and didn’t allow the advancing saltwater wedge toe to be intruded beyond the wells.

  11. 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

  12. Process Based Explanations for Correlations Between the Structural and Seismic Segmentation of the Cascadia Subduction Wedge

    Science.gov (United States)

    Fuller, C. W.; Brandon, M. T.; Willett, S. D.

    2006-12-01

    Variations in the geological and geophysical characteristics of the Cascadia subduction wedge, the region between the trench and arc, result in along-strike wedge segmentation. We focus on explaining the large-scale structural segmentation and how processes causing this segmentation influence segmentation with respect to the seismic behavior of the wedge and subduction thrust. The relationships we develop illustrate the fundamental interplay of processes controlling long-term structure and short-term seismic behavior. Our conclusions are based on the results of numerical models designed to simulate the growth and evolution of the Cascadia subduction wedge through the accretion of a thin layer of sediment to the basaltic Coast Range Terrane (CRT) of the Cascadia margin. Two aspects of wedge structural segmentation are of interest: (1) segmentation with respect to the location or absence of large, continental shelf, forearc basins, and (2) segmentation with respect to the Coastal Range (CR) structural high. Our models illustrate that the form of the submarine portion of the Cascadia wedge, including the basins or lack thereof, is a consequence of the frictional behavior of this region of wedge, subduction thrust strength, wedge strength, and dip thrust. We propose that basin segments have stronger wedge material, a weaker thrust, or a steeper thrust than basin free segments. The presence of basins is significant because they stabilize the margin and prevent subduction and accretion related deformation. This stabilization allows the thrust to preferentially support thermally induced, fluid overpressures and undergo fault healing thus increasing the likelihood of large coseismic slip within basin segments. While no historical earthquake data supporting this argument exists for Cascadia, such behavior has been observed in many margins (Song and Simons, 2003; Wells et al., 2003). It is reasonable to assume that large earthquakes in Cascadia will have the same association

  13. Enquistación in vitro de Giardia lamblia: análisis por electroforesis bidimensional de proteínas expresadas diferencialmente.

    Directory of Open Access Journals (Sweden)

    Paula C. Hernández

    2002-09-01

    Full Text Available La reconstrucción in vitro del ciclo de vida de Giardia lamblia es un excelente instrumento para el estudio de la biología molecular del parásito. El presente trabajo pretende contribuir al desarrollo de algunas técnicas por las cuales se puede definir mejor un modelo de diferenciación celular del parásito. El estudio presenta un protocolo de enquistación in vitro y establece un método para el aislamiento y la purificación de los quistes producidos, cuyas características morfológicas, por microscopía de luz, coinciden con las de los quistes obtenidos in vivo. Se estudió el mapa de las proteínas de G. lamblia por medio de electroforesis bidimensional de alta resolución y de electroforesis en una dimensión. Estos estudios mostraron que la mayoría de las proteínas del parásito son de carácter ácido. Se amplió, con base en ese resultado, la resolución de la región ácida por medio de un isoelectroenfoque de pH 4-7 en la primera dimensión. Se encontraron diferencias en la expresión de las proteínas durante el proceso de enquistación. Se obtuvieron, además, imágenes por microscopía de luz y electrónica de transmisión que permitieron observar morfológica y ultraestructuralmente las células producidas durante el proceso de la enquistación.

  14. Lie algebraic approach to the time-dependent quantum general harmonic oscillator and the bi-dimensional charged particle in time-dependent electromagnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Ibarra-Sierra, V.G.; Sandoval-Santana, J.C. [Departamento de Física, Universidad Autónoma Metropolitana Iztapalapa, Av. San Rafael Atlixco 186, Col. Vicentina, 09340 México D.F. (Mexico); Cardoso, J.L. [Área de Física Teórica y Materia Condensada, Universidad Autónoma Metropolitana Azcapotzalco, Av. San Pablo 180, Col. Reynosa-Tamaulipas, Azcapotzalco, 02200 México D.F. (Mexico); Kunold, A., E-mail: akb@correo.azc.uam.mx [Área de Física Teórica y Materia Condensada, Universidad Autónoma Metropolitana Azcapotzalco, Av. San Pablo 180, Col. Reynosa-Tamaulipas, Azcapotzalco, 02200 México D.F. (Mexico)

    2015-11-15

    We discuss the one-dimensional, time-dependent general quadratic Hamiltonian and the bi-dimensional charged particle in time-dependent electromagnetic fields through the Lie algebraic approach. Such method consists in finding a set of generators that form a closed Lie algebra in terms of which it is possible to express a quantum Hamiltonian and therefore the evolution operator. The evolution operator is then the starting point to obtain the propagator as well as the explicit form of the Heisenberg picture position and momentum operators. First, the set of generators forming a closed Lie algebra is identified for the general quadratic Hamiltonian. This algebra is later extended to study the Hamiltonian of a charged particle in electromagnetic fields exploiting the similarities between the terms of these two Hamiltonians. These results are applied to the solution of five different examples: the linear potential which is used to introduce the Lie algebraic method, a radio frequency ion trap, a Kanai–Caldirola-like forced harmonic oscillator, a charged particle in a time dependent magnetic field, and a charged particle in constant magnetic field and oscillating electric field. In particular we present exact analytical expressions that are fitting for the study of a rotating quadrupole field ion trap and magneto-transport in two-dimensional semiconductor heterostructures illuminated by microwave radiation. In these examples we show that this powerful method is suitable to treat quadratic Hamiltonians with time dependent coefficients quite efficiently yielding closed analytical expressions for the propagator and the Heisenberg picture position and momentum operators. -- Highlights: •We deal with the general quadratic Hamiltonian and a particle in electromagnetic fields. •The evolution operator is worked out through the Lie algebraic approach. •We also obtain the propagator and Heisenberg picture position and momentum operators. •Analytical expressions for a

  15. Bidimensional cationic ordering and thermal dependence in {beta}-Pb{sub x}V{sub 2}O{sub 5} bronzes

    Energy Technology Data Exchange (ETDEWEB)

    Mentre, O.; Huve, M.; Abraham, F. [Univ. des Sciences et Technologies de Lille, Villeneuve d`Ascq (France). Lab. de Cristallochimie et Physicochimie du Solide

    1999-06-01

    The monoclinic lead vanadium oxide bronzes {beta}-Pb{sub x}V{sub 2}O{sub 5} were investigated for their cationic ordering within the host lattice. Superstructure reflections appear on X-ray powder patterns beyond x {approx} 0.30. For the formal x = 0.30 lead radio, the crystal structure was refined from X-ray single crystal data in the (a, 2b, c) unit cell, a = 15.478(10) {angstrom}, 2b = 7.288(5) {angstrom}, c = 10.123(6) {angstrom}, {beta} = 109.29(1){degree}, S. G. P2{sub 1}/m and final R = 0.047, R{sub w} = 0.054. It shows evidence of an intratunnel ordering involving a Pb{sup 2+} zigzag sequence running parallel to the b axis while ordered and disordered tunnels alternate along the a axis. Pb{sup 2+} display different interaction with the V-O framework according to the kind of tunnels it occupies. Electron diffraction patterns confirmed the X-ray results. A supplementary 2a periodicity was sometimes observed in small crystals as a subcondition of the previous ordering. Weissenberg photographs and electronic diffraction patterns allowed the proposition of a bidimensional cationic ordering model in the fourfold (2a, 2b, c) unit cell. In that case, the intertunnel ordering involves strong local Pb{sup 2+} electrostatic effects despite the shielding of the tunnel walls. The thermal analysis (DTA and high temperature electronic microscopy) evidenced the irreversible disappearing of the superstructure on heating while a second rearrangement is observed on cooling. 28 refs., 12 figs., 5 tabs.

  16. Effect of Laterally Wedged Insoles on the External Knee Adduction Moment across Different Reference Frames.

    Directory of Open Access Journals (Sweden)

    Satoshi Yamaguchi

    Full Text Available Biomechanical effects of laterally wedged insoles are assessed by reduction in the knee adduction moment. However, the degree of reduction may vary depending on the reference frame with which it is calculated. The purpose of this study was to clarify the effect of reference frame on the reduction in the knee adduction moment by laterally wedged insoles.Twenty-nine healthy participants performed gait trials with a laterally wedged insole and with a flat insole as a control. The knee adduction moment, including the first and second peaks and the angular impulse, were calculated using four different reference frames: the femoral frame, tibial frame, laboratory frame and the Joint Coordinate System.There were significant effects of reference frame on the knee adduction moment first and second peaks (P < 0.001 for both variables, while the effect was not significant for the angular impulse (P = 0.84. No significant interaction between the gait condition and reference frame was found in either of the knee adduction moment variables (P = 0.99 for all variables, indicating that the effects of laterally wedged insole on the knee adduction moments were similar across the four reference frames. On the other hand, the average percent changes ranged from 9% to 16% for the first peak, from 16% to 18% for the second peak and from 17% to 21% for the angular impulse when using the different reference frames.The effects of laterally wedged insole on the reduction in the knee adduction moment were similar across the reference frames. On the other hand, Researchers need to recognize that when the percent change was used as the parameter of the efficacy of laterally wedged insole, the choice of reference frame may influence the interpretation of how laterally wedged insoles affect the knee adduction moment.

  17. Prediction of knee joint moment changes during walking in response to wedged insole interventions.

    Science.gov (United States)

    Lewinson, Ryan T; Stefanyshyn, Darren J

    2016-04-01

    Wedged insoles are prescribed for medial knee osteoarthritis to reduce the knee adduction moment; however, it is currently not possible to predict which patients will in fact experience reduced moments. The purpose of this study was to identify a simple method using two-dimensional data for predicting the expected change in knee adduction moments with wedged insoles. Knee adduction moments during walking were determined for healthy individuals (n = 15) and individuals with medial knee osteoarthritis (n = 19) while wearing their own shoe without an insole (control), with a 6-mm medial wedge and with a 6-mm lateral wedge. The percent changes relative to control were determined. Then, participants completed single-step trials with each footwear condition where only the changes in mediolateral positions of the knee joint center, shank center of mass, ankle joint center, and foot center of mass relative to control were determined. These variables were used as predictors in regression equations where the change in knee adduction moment during walking was the dependent variable. The change in mediolateral positions of the lower extremity during a single step significantly predicted the change in knee adduction moment during walking for the lateral wedge in both the healthy (R(2) = 0.72, p = 0.008) and knee osteoarthritis (R(2) = 0.52, p = 0.026) groups, and also for the medial wedge in both the healthy (R(2) = 0.67, p = 0.016) and knee osteoarthritis (R(2) = 0.54, p = 0.020) groups. The method of using mediolateral position data from a single-step movement to predict walking biomechanics was successful. These data are relatively simple to collect and analyze, offering the possibility for future incorporation into a wedge prediction system. © IMechE 2016.

  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 Møller; Kersting, Uwe G.

    2013-01-01

    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...... 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...... and second peak knee adduction moments. However, the variability of this moment between shoe designs was of similar magnitude as the effect of laterally wedged insoles. Only marginal changes in muscle activity for gastrocnemius when walking with the wedged Oxford shoe were revealed. Conclusion: Lateral...

  19. Total knee arthroplasty after failed high tibial osteotomy: a systematic review of open versus closed wedge osteotomy.

    Science.gov (United States)

    Han, Jae Hwi; Yang, Jae-Hyuk; Bhandare, Nikhl N; Suh, Dong Won; Lee, Jong Seong; Chang, Yong Suk; Yeom, Ji Woong; Nha, Kyung Wook

    2016-08-01

    Medial opening wedge high tibial osteotomy (HTO) has become increasingly popular as an alternative to lateral closing wedge osteotomy for the treatment of medial compartment knee osteoarthritis with varus deformity. The present systematic review was conducted to provide an objective analysis of total knee arthroplasty (TKA) outcomes following previous knee osteotomy (medial opening wedge vs. lateral closing wedge). A literature search of online databases (MEDLINE, EMBASE, Cochrane Library database) was made, in addition to manual search of major orthopaedic journals. The methodological quality of each of the studies was assessed on the Newcastle-Ottawa Scale and Effective Practice and Organization of Care. A total of ten studies were included in the review. There were eight studies with Level IV and two studies with Level III evidence. Eight studies reported clinical and radiologic scores. Comparative studies between TKA following medial opening and lateral closing wedge HTO did not demonstrate statistically significant clinical and radiologic differences. The revision rates were similar. However, more technical issues during TKA surgery after lateral closing wedge HTO were mentioned than the medial open wedge group. The quadriceps snip, tibial tubercle osteotomy, and lateral soft tissue release were more frequently needed in the lateral closing wedge HTO group. In addition, because of loss of proximal tibia bone geometry in the lateral closing wedge HTO group, concerns such as tibia stem impingement in the lateral tibial cortex was noted. The present systematic review suggests that TKA after medial opening and lateral closing wedge HTO showed similar performance. Clinical and radiologic outcome including revision rates did not statistically differ from included studies. However, there are more surgical technical concerns in TKA conversion from lateral closing wedge HTO than from the medial opening wedge HTO group. IV.

  20. Study and evaluation of the Siemens virtual wedge factor: dosimetric monitor system and variable field effects

    Energy Technology Data Exchange (ETDEWEB)

    Sendon Rio, J R Sendon; Martinez, C Otero; GarcIa, M Sanchez; Busto, R Lobato; Vega, V Luna; Sueiro, J Mosquera; Camean, M Pombar [Servizo de Radiofisica e Proteccion Radioloxica, Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), Santiago de Compostela (Spain)], E-mail: jose.ramon.sendon.del.rio@sergas.es

    2008-03-07

    In the year 1997 Siemens introduced the virtual wedge in its accelerators. The idea was that a dose profile similar to that of a physical wedge can be obtained by moving one of the accelerator jaws at a constant speed while the dose rate is changing. This work explores the observed behaviour of virtual wedge factors. A model is suggested which takes into account that at any point in time, when the jaw moves, the dose at a point of interest in the phantom is not only due to the direct beam. It also depends on the scattered radiation in the phantom, the head scatter and the behaviour of the monitoring system of the accelerator. Measurements are performed in a Siemens Primus accelerator and compared to the model predictions. It is shown that the model agrees reasonably well with measurements spanning a wide range of conditions. A strong dependence of virtual wedge factors on the dosimetric board has been confirmed and an explanation has been given on how the balance between different contributions is responsible for virtual wedge factors values.

  1. Analysis of bonded anisotropic wedges with interface crack under anti-plane shear loading

    Institute of Scientific and Technical Information of China (English)

    M.GHADIRI; A.R.SHAHANI

    2014-01-01

    The antiplane stress analysis of two anisotropic finite wedges with arbitrary radii and apex angles that are bonded together along a common edge is investigated. The wedge radial boundaries can be subjected to displacement-displacement boundary condi-tions, and the circular boundary of the wedge is free from any traction. The new finite complex transforms are employed to solve the problem. These finite complex transforms have complex analogies to both kinds of standard finite Mellin transforms. The traction free condition on the crack faces is expressed as a singular integral equation by using the exact analytical method. The explicit terms for the strength of singularity are extracted, showing the dependence of the order of the stress singularity on the wedge angle, material constants, and boundary conditions. A numerical method is used for solving the resul-tant singular integral equations. The displacement boundary condition may be a general term of the Taylor series expansion for the displacement prescribed on the radial edge of the wedge. Thus, the analysis of every kind of displacement boundary conditions can be obtained by the achieved results from the foregoing general displacement boundary condition. The obtained stress intensity factors (SIFs) at the crack tips are plotted and compared with those obtained by the finite element analysis (FEA).

  2. Proximal first metatarsal opening wedge osteotomy: geometric analysis on saw bone models.

    Science.gov (United States)

    Kugan, R; Currall, V A; Johal, P; Clark, C I C

    2015-03-01

    For hallux valgus correction, distal first metatarsal osteotomy is generally used for minor to moderate deformities, diaphyseal osteotomy for moderate deformities and basal osteotomy or arthrodesis for severe deformities. With the advent of locking plates, there has been renewed interest in opening wedge basal osteotomy. We undertook this study in order to understand the power and limitations of this osteotomy. Proximal opening wedge osteotomies were performed on saw bone models in four orientations, with three different wedge sizes: (1) perpendicular to the ground (PG); (2) perpendicular to the shaft (PS); (3) perpendicular to shaft with 30° declination (DEC); (4) 30° oblique (OB). Pre- and post-osteotomy measurements were made of axial and plantar translation and inter-metatarsal angle. Plantar translation and intermetatarsal angle correction increased with increasing wedge size. The DEC osteotomy produced the greatest increase in length of metatarsal shaft, while the PS osteotomy gave the least. The most plantar translation was achieved with the DEC osteotomy. Overall, the PS osteotomy gave the largest correction of the intermetatarsal angle. Although there are several published clinical case series of the proximal opening wedge osteotomy, this is the first study to fully evaluate its geometry. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Enhanced dynamic wedge output factors for Varian 2300CD and the case for a reference database.

    Science.gov (United States)

    Njeh, Christopher F

    2015-09-08

    Dose inhomogeneity in treatment planning can be compensated using physical wedges. Enhanced dynamic wedges (EDW) were introduced by Varian to overcome some of the shortcomings of physical wedges. The objectives of this study were to measure EDW output factors for 6 MV and 20 MV photon energies for a Varian 2300CD. Secondly, to review the literature in terms of published enhanced dynamic wedge output factors (EDWOF) for different Varian models and thereby add credence to the case of the validity of reference databases. The enhanced dynamic wedge output factors were measured for the Varian 2300CD for both 6MV and 20 MV photon energies. Twelve papers with published EDWOF for different Varian linac models were found in the literature. Comparing our results with the published mean, we found an excellent agreement for 6 MV EDWOF, with the percentage differences ranging from 0.01% to 0.57%, with a mean of 0.03%. The coefficient of variation of published EDWOF ranged from 0.17% to 0.85% and 0.1% to 0.9% for the for 6 MV and 18 MV photon energies, respectively. This paper provides the first published EDWOF for 20 MV photon energy. In addition, we have provided the first compendium of EDWOFs for different Varian linac models. The consistency of value across models and institution provide further support that a standard dataset of basic photon and electron dosimetry could be established as a guide for future commissioning, beam modeling, and quality assurance purposes.

  4. Seismic evidence for a cold serpentinized mantle wedge beneath Mount St Helens.

    Science.gov (United States)

    Hansen, S M; Schmandt, B; Levander, A; Kiser, E; Vidale, J E; Abers, G A; Creager, K C

    2016-11-01

    Mount St Helens is the most active volcano within the Cascade arc; however, its location is unusual because it lies 50 km west of the main axis of arc volcanism. Subduction zone thermal models indicate that the down-going slab is decoupled from the overriding mantle wedge beneath the forearc, resulting in a cold mantle wedge that is unlikely to generate melt. Consequently, the forearc location of Mount St Helens raises questions regarding the extent of the cold mantle wedge and the source region of melts that are responsible for volcanism. Here using, high-resolution active-source seismic data, we show that Mount St Helens sits atop a sharp lateral boundary in Moho reflectivity. Weak-to-absent PmP reflections to the west are attributed to serpentinite in the mantle-wedge, which requires a cold hydrated mantle wedge beneath Mount St Helens (<∼700 °C). These results suggest that the melt source region lies east towards Mount Adams.

  5. Medial Closing-Wedge Distal Femoral Osteotomy for Genu Valgum With Lateral Compartment Disease.

    Science.gov (United States)

    Wylie, James D; Maak, Travis G

    2016-12-01

    Lateral compartment disease combined with valgus alignment can lead to progressive knee joint degeneration. In the symptomatic patient with isolated lateral compartment disease, a varus-producing distal femoral osteotomy can unload the diseased lateral compartment. This osteotomy may be combined with other cartilage or meniscal restorative techniques to optimize knee joint preservation and pain relief. The osteotomy can be performed with a medial closing-wedge or lateral opening-wedge technique. Both techniques have been reported to improve knee-related quality of life in patients with lateral compartment disease. Advantages of the medial closing-wedge technique are direct bone apposition leading to inherent stability of the construct, as well as reliable bony healing, and less hardware irritation. Advantages of the lateral opening-wedge technique are a single bony cut and therefore more of an ability to adjust correction intraoperatively. However, this technique requires bone grafting and has a high rate of hardware irritation or removal. We present a surgical technique for the medial closing-wedge distal femoral osteotomy using an anteromedial-distal femoral locking plate.

  6. Parental arc magma compositions dominantly controlled by mantle-wedge thermal structure

    Science.gov (United States)

    Turner, Stephen J.; Langmuir, Charles H.; Katz, Richard F.; Dungan, Michael A.; Escrig, Stéphane

    2016-10-01

    The processes that lead to the fourfold variation in arc-averaged compositions of mafic arc lavas remain controversial. Control by the mantle-wedge thermal structure is supported by chemical correlations with the thickness of the underlying arc crust, which affects the thermal state of the wedge. Control by down-going slab temperature is supported by correlations with the slab thermal parameter. The Chilean Southern Volcanic Zone provides a test of these hypotheses. Here we use chemical data to demonstrate that the Southern Volcanic Zone and global arc averages define the same chemical trends, both among elements and between elements and crustal thickness. But in contrast to the global arc system, the Southern Volcanic Zone is built on crust of variable thickness with a constant slab thermal parameter. This natural experiment, along with a set of numerical simulations, shows that global arc compositional variability is dominated by different extents of melting that are controlled by the thermal structure of the mantle wedge. Slab temperatures play a subordinate role. Variations in the subducting slab's fluid flux and sediment compositions, as well as mantle-wedge heterogeneities, produce second-order effects that are manifested as distinctive trace element and isotopic signatures; these can be more clearly elucidated once the importance of wedge thermal structure is recognized.

  7. Measurement of photoneutron dose produced by wedge filters of a high energy linac using polycarbonate films.

    Science.gov (United States)

    Hashemi, Seyed Mehdi; Hashemi-Malayeri, Bijan; Raisali, Gholamreza; Shokrani, Parvaneh; Sharafi, Ali Akbar; Torkzadeh, Falamarz

    2008-05-01

    Radiotherapy represents the most widely spread technique to control and treat cancer. To increase the treatment efficiency, high energy linacs are used. However, applying high energy photon beams leads to a non-negligible dose of neutrons contaminating therapeutic beams. In addition, using conventional linacs necessitates applying wedge filters in some clinical conditions. However, there is not enough information on the effect of these filters on the photoneutrons produced. The aim of this study was to investigate the change of photoneutron dose equivalent due to the use of linac wedge filters. A high energy (18 MV) linear accelerator (Elekta SL 75/25) was studied. Polycarbonate films were used to measure the dose equivalent of photoneutrons. After electrochemical etching of the films, the neutron dose equivalent was calculated using Hp(10) factor, and its variation on the patient plane at 0, 5, 10, 50 and 100 cm from the center of the X-ray beam was determined. By increasing the distance from the center of the X-ray beam towards the periphery, the photoneutron dose equivalent decreased rapidly for the open and wedged fields. Increasing of the field size increased the photoneutron dose equivalent. The use of wedge filter increased the proportion of the neutron dose equivalent. The increase can be accounted for by the selective absorption of the high energy photons by the wedge filter.

  8. Trusted Domain

    DEFF Research Database (Denmark)

    Hjorth, Theis Solberg; Torbensen, Rune

    2012-01-01

    that enables secure end-to-end communication with home automation devices, and it supports device revocations as well as a structure of intersecting sets of nodes for scalability. Devices in the Trusted Domain are registered in a list that is distributed using a robust epidemic protocol optimized...

  9. Domain crossing

    DEFF Research Database (Denmark)

    Schraefel, M. C.; Rouncefield, Mark; Kellogg, Wendy

    2012-01-01

    In CSCW, how much do we need to know about another domain/culture before we observe, intersect and intervene with designs. What optimally would that other culture need to know about us? Is this a “how long is a piece of string” question, or an inquiry where we can consider a variety of contexts a...

  10. A fully integrated high-Q Whispering-Gallery Wedge Resonator

    CERN Document Server

    Ramiro-Manzano, F; Pavesi, L; Pucker, G; Ghulinyan, M

    2012-01-01

    Microresonator devices which posses ultra-high quality factors are essential for fundamental investigations and applications. Microsphere and microtoroid resonators support remarkably high Q's at optical frequencies, while planarity constrains preclude their integration into functional lightwave circuits. Conventional semiconductor processing can also be used to realize ultra-high-Q's with planar wedge-resonators. Still, their full integration with side-coupled dielectric waveguides remains an issue. Here we show the full monolithic integration of a wedge-resonator/waveguide vertically-coupled system on a silicon chip. In this approach the cavity and the waveguide lay in different planes. This permits to realize the shallow-angle wedge while the waveguide remains intact, allowing therefore to engineer a coupling of arbitrary strength between these two. The precise size-control and the robustness against post-processing operation due to its monolithic integration makes this system a prominent platform for indu...

  11. 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.

  12. 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...... 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...

  13. 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.

  14. Stress singularity in a top of composite wedge with internal functionally graded material

    Directory of Open Access Journals (Sweden)

    Victor V. Tikhomirov

    2015-10-01

    Full Text Available The antiplane problem of the composite wedge consisting of two homogeneous external wedge-shaped areas and an intermediate zone of the interphase is studied. The interphase material is assumed functionally graded. It is shown that the problem in each area is harmonic within the quadratic law of inhomogeneity of the material in the transverse direction. The influence of the interphase on the stress state at the top of the wedge is analyzed. As compared to the ideal contact of external materials, the presence of the interphase leads both to decrease and increase in the singularity exponent. Moreover, the stress asymptotic may have two singular terms for some values of the composite parameters.

  15. Water Impact of Rigid Wedges in Two-Dimensional Fluid Flow

    Directory of Open Access Journals (Sweden)

    Sawan Shah

    2015-01-01

    Full Text Available A combined experimental and numerical investigation was conducted into impact of rigid wedges on water in two-dimensional fluid conditions. Drop test experiments were conducted involving symmetric rigid wedges of varying angle and mass impacted onto water. The kinematic behaviour of the wedge and water was characterised using high-speed video. Numerical models were analysed in LS-DYNA® that combined regions of Smoothed Particle Hydrodynamics particles and a Lagrangian element mesh. The analysis captured the majority of experimental results and trends, within the bounds of experimental variance. Further, the combined modelling technique presented a highly attractive combination of computational efficiency and accuracy, making it a suitable candidate for aircraft ditching investigations.

  16. 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.

  17. Pervasive seismic wave reflectivity and metasomatism of the Tonga mantle wedge.

    Science.gov (United States)

    Zheng, Yingcai; Lay, Thorne; Flanagan, Megan P; Williams, Quentin

    2007-05-11

    Subduction zones play critical roles in the recycling of oceanic lithosphere and the generation of continental crust. Seismic imaging can reveal structures associated with key dynamic processes occurring in the upper-mantle wedge above the sinking oceanic slab. Three-dimensional images of reflecting interfaces throughout the upper-mantle wedge above the subducting Tonga slab were obtained by migration of teleseismic recordings of underside P- and S-wave reflections. Laterally continuous weak reflectors with tens of kilometers of topography were detected at depths near 90, 125, 200, 250, 300, 330, 390, 410, and 450 kilometers. P- and S-wave impedances decreased at the 330-kilometer and 450-kilometer reflectors, and S-wave impedance decreased near 200 kilometers in the vicinity of the slab and near 390 kilometers, just above the global 410-kilometer increase. The pervasive seismic reflectivity results from phase transitions and compositional zonation associated with extensive metasomatism involving slab-derived fluids rising through the wedge.

  18. Growth of the deposit wedge in the mountain reservoir

    Science.gov (United States)

    Chen, Y.; Song, G.

    2011-12-01

    The sedimentary problem of mountain reservoirs in Taiwan is getting serious year by year.Due to eroded sediments enter downstream reservoirs,the loss of sediment transport capacity may cause deposition of sediment in reservoirs.This phenomenon make problems to small mountain reservoirs.To realize the interaction between deposit wedges and mountain reservoirs,we selected Wushe reservoir which is situated in central Taiwan for a case study. Wushe reservoir is long and narrow.In recent years,most sediment is introduced during rain events that now accompany climate change are very important in sediment supply.In this thesis,we collected data of underwater landform and sub-bottom bedding information by using high resolution Multibeam Survey System(MBS) and seismic-reflection system.Up to now,we already had the bathymetric data for more than ten years,moreover,in 2010,we used 3.5kHz sub-bottom seismic profiler to analysis the sedimentary bedding situation in this area.These methods provide us accurate reservoir topography,sediment accumulation and the major ways of sediment transportation.The study purposes are as follows: First,according to the available underwater data for last ten years,we recognize the geomorphological characters of sedimentation as well as complete the mappings.Comparing to bathymetric images each year,we evaluate the carried ways of sediment.The flow water which enters this area transports along the thalweg,which in eastern reservoir.The range of water level variation cause alteration of sedimentary morphology,it also affects the scope of alluvial fan.The alluvial fan is located in the middle of the reservoir,the edge of it had moved forward 500 meters for last ten years.The annual mean of forward velocity was 50 meters,the elevation of fan edge also accelerated 10 meters per year.In a word,the large volume of the sedimentary delta is in Wushe reservoir now. Second,trying to clarify the composition of sedimentation and explain the sub

  19. Quantitative comparisons of analogue models of brittle wedge dynamics

    Science.gov (United States)

    Schreurs, Guido

    2010-05-01

    Analogue model experiments are widely used to gain insights into the evolution of geological structures. In this study, we present a direct comparison of experimental results of 14 analogue modelling laboratories using prescribed set-ups. A quantitative analysis of the results will document the variability among models and will allow an appraisal of reproducibility and limits of interpretation. This has direct implications for comparisons between structures in analogue models and natural field examples. All laboratories used the same frictional analogue materials (quartz and corundum sand) and prescribed model-building techniques (sieving and levelling). Although each laboratory used its own experimental apparatus, the same type of self-adhesive foil was used to cover the base and all the walls of the experimental apparatus in order to guarantee identical boundary conditions (i.e. identical shear stresses at the base and walls). Three experimental set-ups using only brittle frictional materials were examined. In each of the three set-ups the model was shortened by a vertical wall, which moved with respect to the fixed base and the three remaining sidewalls. The minimum width of the model (dimension parallel to mobile wall) was also prescribed. In the first experimental set-up, a quartz sand wedge with a surface slope of ˜20° was pushed by a mobile wall. All models conformed to the critical taper theory, maintained a stable surface slope and did not show internal deformation. In the next two experimental set-ups, a horizontal sand pack consisting of alternating quartz sand and corundum sand layers was shortened from one side by the mobile wall. In one of the set-ups a thin rigid sheet covered part of the model base and was attached to the mobile wall (i.e. a basal velocity discontinuity distant from the mobile wall). In the other set-up a basal rigid sheet was absent and the basal velocity discontinuity was located at the mobile wall. In both types of experiments

  20. Balloon occlusion versus wedged hepatic venography using iodinated contrast for targeting the portal vein during TIPS.

    Science.gov (United States)

    Caporossi, J-M; Vidal, V; Jacquier, A; Reyre, A; Flavian, A; Muller, C; Gaubert, J-Y; Bartoli, J-M; Moulin, G; Varoquaux, A

    2015-04-01

    To assess the efficacy, safety and gain in procedure time of the technique of balloon occlusion hepatic venography with iodinated contrast used to target the portal vein during TIPS. The technique is assessed versus wedged hepatic venography. Fifty-eight TIPS were prospectively included. The portal vein was located in 30 cases by the wedged hepatic venography (group 1) and in 28 cases by balloon occlusion hepatic venography (group 2). To compare both techniques a "portogram quality" score was defined using a 5 points scale. The time required to achieve portal puncture was also recorded. The complications of both procedures were assessed and classified in groups as intrahepatic hematoma or intraperitoneal hemorrhage. The right portal vein was visualized in a significantly higher number of patients using balloon than with wedged retrograde venography 71.3% (20/28) versus 13.3% (4/30) respectively (P=0.002). The quality score for the portogram was significantly higher for balloon hepatic venography 2.21 than for wedged hepatic venography 1.07 (P=0.002). The mean time required to puncture the portal vein was significantly shorter when the right branch of the portal vein was visualized 21 min versus 33.5 min (P=0.046). We recorded one intrahepatic hematoma (3.3%) and 4 intraperitoneal hemorrhage (13.3%) secondary to wedged hepatic venography. There were no complications with balloon occlusion hepatic venography (P=0.053). The use of balloon occlusion hepatic venography improves the quality of the retrograde portal venography to target the portal vein and decreases procedure time. The balloon technique is also burdened with fewer complications than the standard wedged hepatic venography. Copyright © 2014 Éditions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

  1. P-wave anisotropy, mantle wedge flow and olivine fabrics beneath Japan

    Science.gov (United States)

    Liu, Xin; Zhao, Dapeng

    2017-09-01

    We present a new 3-D anisotropic P-wave velocity (Vp) model for the crust and upper mantle of the Japan subduction zone obtained by inverting a large number of high-quality P-wave traveltime data of local earthquakes and teleseismic events. By assuming orthorhombic anisotropy with a vertical symmetry axis existing in the modeling space, isotropic Vp tomography and 3-D Vp azimuthal and radial anisotropies are determined simultaneously. According to a simple flow field and the obtained Vp anisotropic tomography, we estimate the distribution of olivine fabrics in the mantle wedge. Our results show that the forearc mantle wedge above the subducting Pacific slab beneath NE Japan exhibits an azimuthal anisotropy with trench-parallel fast velocity directions (FVDs) and Vhf > Vv > Vhs (here Vv is Vp in the vertical direction, Vhf and Vhs are P-wave velocities in the fast and slow directions in the horizontal plane), where B-type olivine fabric with vertical trench-parallel flow may dominate. Such an anisotropic feature is not obvious in the forearc mantle wedge above the Philippine Sea (PHS) slab under SW Japan, probably due to higher temperatures and more fluids there associated with the young and warm PHS slab subduction. Trench-normal FVDs and Vhf > Vv > Vhs are generally revealed in the mantle wedge beneath the arc and backarc in Japan, where E-type olivine fabric with FVD-parallel horizontal flow may dominate. Beneath western Honshu, however, the mantle wedge exhibits an anisotropy of Vv > Vhf > Vhs and so C-type olivine fabric may dominate, suggesting that the water content is the highest there, because both the PHS and Pacific slabs exist there and their dehydration reactions release abundant fluids to the overlying mantle wedge.

  2. Tectonic and gravity extensional collapses in overpressured cohesive and frictional wedges

    Science.gov (United States)

    Yuan, X. P.; Leroy, Y. M.; Maillot, B.

    2015-03-01

    Two modes of extensional collapse in a cohesive and frictional wedge of arbitrary topography, finite extent, and resting on an inclined weak décollement are examined by analytical means. The first mode consists of the gravitational collapse by the action of a half-graben, rooting on the décollement and pushing seaward the frontal part of the wedge. The second mode results from the tectonics extension at the back wall with a similar half-graben kinematics and the landward sliding of the rear part of the wedge. The predictions of the maximum strength theorem, equivalent to the kinematic approach of limit analysis and based on these two collapse mechanisms, not only match exactly the solutions of the critical Coulomb wedge theory, once properly amended, but generalizes them in several aspects: wedge of finite size, composed of cohesive material and of arbitrary topography. This generalization is advantageous to progress in our understanding of many laboratory experiments and field cases. For example, it is claimed from analytical results validated by experiments that the stability transition for a cohesive, triangular wedge occurs with the activation of the maximum length of the décollement. It is shown that the details of the topography, for the particular example of the Mejillones peninsula (North Chile) is, however, responsible for the selection of a short length-scale, dynamic instability corresponding to a frontal gravitational instability. A reasonable amount of cohesion is sufficient for the pressures proposed in the literature to correspond to a stability transition and not with a dynamically unstable state.

  3. Los recursos tecnológicos en la estadística bidimensional en los textos españoles de bachillerato

    Directory of Open Access Journals (Sweden)

    María M. Gea

    2015-12-01

    Full Text Available Los currículos actuales recomiendan el uso de los recursos tecnológicos en la enseñanza de la estadística, por la ventaja que suponen en el cálculo y representación gráfica, el trabajo con datos reales y el aprendizaje de conceptos a través de la simulación. En esta investigación se analizan los recursos tecnológicos que los libros de texto sugieren para la enseñanza y aprendizaje de la estadística bidimensional en bachillerato (organización y representación de datos bidimensionales, correlación y regresión. La importancia de este aspecto se debe a que extiende la dependencia funcional a situaciones aleatorias y proporciona al alumno oportunidades de modelizar numerosas aplicaciones. Por otro lado, la investigación didáctica muestra dificultades de comprensión y concepciones erróneas en esta área. Mediante un análisis de contenido se han estudiado dieciséis libros de texto españoles, ocho libros de cada una de las dos especialidades de bachillerato que incluyen “Humanidades y Ciencias Sociales” y “Ciencia y Tecnología”. En dichos libros se estudia el uso que se hace de recursos tecnológicos en los problemas y procedimientos propuestos, los tipos de recursos que se referencian para trabajar con internet y el contenido de un CD que acompaña a la mayoría de estos textos. Los resultados muestran una escasa presencia de recursos tecnológicos en los textos analizados, a la vez que una gran variabilidad de los recursos descritos. La referencia a recursos en internet se suele restringir a unidades didácticas y no a conjuntos de datos que puedan usarse en proyectos o a simuladores que faciliten la comprensión conceptual. El CD que acompaña a los textos a veces reproduce el mismo texto o se reduce a colecciones de ejercicios tradicionales; son minoría los problemas y procedimientos que usan recursos tecnológicos. Se concluye con algunas recomendaciones para la mejora de estos textos, teniendo en cuenta dichos

  4. Multisource Remote Sensing Imagery Fusion Scheme Based on Bidimensional Empirical Mode Decomposition (BEMD and Its Application to the Extraction of Bamboo Forest

    Directory of Open Access Journals (Sweden)

    Guang Liu

    2016-12-01

    Full Text Available Most bamboo forests grow in humid climates in low-latitude tropical or subtropical monsoon areas, and they are generally located in hilly areas. Bamboo trunks are very straight and smooth, which means that bamboo forests have low structural diversity. These features are beneficial to synthetic aperture radar (SAR microwave penetration and they provide special information in SAR imagery. However, some factors (e.g., foreshortening can compromise the interpretation of SAR imagery. The fusion of SAR and optical imagery is considered an effective method with which to obtain information on ground objects. However, most relevant research has been based on two types of remote sensing image. This paper proposes a new fusion scheme, which combines three types of image simultaneously, based on two fusion methods: bidimensional empirical mode decomposition (BEMD and the Gram-Schmidt transform. The fusion of panchromatic and multispectral images based on the Gram-Schmidt transform can enhance spatial resolution while retaining multispectral information. BEMD is an adaptive decomposition method that has been applied widely in the analysis of nonlinear signals and to the nonstable signal of SAR. The fusion of SAR imagery with fused panchromatic and multispectral imagery using BEMD is based on the frequency information of the images. It was established that the proposed fusion scheme is an effective remote sensing image interpretation method, and that the value of entropy and the spatial frequency of the fused images were improved in comparison with other techniques such as the discrete wavelet, à-trous, and non-subsampled contourlet transform methods. Compared with the original image, information entropy of the fusion image based on BEMD improves about 0.13–0.38. Compared with the other three methods it improves about 0.06–0.12. The average gradient of BEMD is 4%–6% greater than for other methods. BEMD maintains spatial frequency 3.2–4.0 higher than

  5. 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.

  6. Molecular depth profiling with cluster secondary ion mass spectrometry and wedges.

    Science.gov (United States)

    Mao, Dan; Wucher, Andreas; Winograd, Nicholas

    2010-01-01

    Secondary ion mass spectrometry and atomic force microscopy are employed to characterize a wedge-shaped crater eroded by 40 keV C(60)(+) bombardment of a 395 nm thin film of Irganox 1010 doped with four delta layers of Irganox 3114. The wedge structure creates a laterally magnified cross section of the film. From an examination of the resulting surface, information about depth resolution, topography, and erosion rate can be obtained as a function of crater depth in a single experiment. This protocol provides a straightforward way to determine the parameters necessary to characterize molecular depth profiles and to obtain an accurate depth scale for erosion experiments.

  7. Global Solutions of Shock Reflection by Wedges for the Nonlinear Wave Equation

    Institute of Scientific and Technical Information of China (English)

    Xuemei DENG; Wei XIANG

    2011-01-01

    When a plane shock hits a wedge head on,it experiences a reflection-diffraction process and then a self-similar reflected shock moves outward as the original shock moves forward in time.In this paper,shock reflection by large-angle wedges for compressible flow modeled by the nonlinear wave equation is studied and a global theory of existence,stability and regularity is established.Moreover,C0,1 is the optimal regularity for the solutions across the degenerate sonic boundary.

  8. Laparoscopic wedge resection of synchronous gastric intraepithelial neoplasia and stromal tumor: a case report.

    Science.gov (United States)

    Mou, Yi-Ping; Xu, Xiao-Wu; Xie, Kun; Zhou, Wei; Zhou, Yu-Cheng; Chen, Ke

    2010-10-21

    Synchronous occurrence of epithelial neoplasia and gastrointestinal stromal tumor (GIST) in the stomach is uncommon. Only rare cases have been reported in the literature. We present here a 60-year-old female case of synchronous occurrence of gastric high-level intraepithelial neoplasia and GIST with the features of 22 similar cases and detailed information reported in the English-language literature summarized. In the present patient, epithelial neoplasia and GIST were removed en bloc by laparoscopic wedge resection. To the best of our knowledge, this is the first reported case treated by laparoscopic wedge resection.

  9. RESEARCH ON THE MOTION CHARACTERISTICS OF FIBER SUSPENSIONS IN A WEDGE-SHAPED FLOW

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this paper the motion of cylindrical particles in a wedge-shaped flow was studied. The velocity distribution of wedge-shaped flow was simulated first, then the Euler-Lagrange model used to calculate the motion of cylindrical particles. The evolution of particle location, velocity and orientation with time was examined. The trajectories of the particles with different particle Stokes number, rate of flow and initial particle orientation were drawn. The results indicate that the Stokes number and initial orientation are important parameters which affect the particle motion. The conclusions are helpful to the engineering applications.

  10. Reconstruction of Bulk Operators within the Entanglement Wedge in Gauge-Gravity Duality

    Science.gov (United States)

    Dong, Xi; Harlow, Daniel; Wall, Aron C.

    2016-07-01

    In this Letter we prove a simple theorem in quantum information theory, which implies that bulk operators in the anti-de Sitter/conformal field theory (AdS/CFT) correspondence can be reconstructed as CFT operators in a spatial subregion A , provided that they lie in its entanglement wedge. This is an improvement on existing reconstruction methods, which have at most succeeded in the smaller causal wedge. The proof is a combination of the recent work of Jafferis, Lewkowycz, Maldacena, and Suh on the quantum relative entropy of a CFT subregion with earlier ideas interpreting the correspondence as a quantum error correcting code.

  11. Bulk Reconstruction in the Entanglement Wedge in AdS/CFT

    CERN Document Server

    Dong, Xi; Wall, Aron C

    2016-01-01

    In this note we prove a simple theorem in quantum information theory, which implies that bulk operators in the Anti-de Sitter / Conformal Field Theory (AdS/CFT) correspondence can be reconstructed as CFT operators in a spatial subregion $A$, provided that they lie in its entanglement wedge. This is an improvement on existing reconstruction methods, which have at most succeeded in the smaller causal wedge. The proof is a combination of the recent work of Jafferis, Lewkowycz, Maldacena, and Suh on the quantum relative entropy of a CFT subregion with earlier ideas interpreting the correspondence as a quantum error correcting code.

  12. 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

    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...

  13. 76 FR 24856 - Heavy Forged Hand Tools (i.e., Axes & Adzes, Bars & Wedges, Hammers & Sledges, and Picks...

    Science.gov (United States)

    2011-05-03

    ..., and Picks & Mattocks) From the People's Republic of China: Final Results of the Expedited Sunset... & Adzes, Bars & Wedges, Hammers & Sledges, and Picks & Mattocks) from the People's Republic of China..., track tools and wedges; (3) picks and mattocks; and (4) axes, adzes and similar hewing tools. Hand...

  14. 76 FR 52313 - Heavy Forged Hand Tools (i.e., Axes & Adzes, Bars & Wedges, Hammers & Sledges, and Picks...

    Science.gov (United States)

    2011-08-22

    ..., and Picks & Mattocks) From the People's Republic of China: Continuation of Antidumping Duty Orders... & 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...

  15. 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.

  16. Semi-infinite $q$-wedge construction of the level 2 Fock Space of $U_q(\\widehat{sl}_2)$

    CERN Document Server

    Petersen, J U H

    1997-01-01

    In this proceedings a particular example from \\cite{KMPY} (q-alg/9603025) is presented: the construction of the level 2 Fock space of $\\U_q(\\affsl{2})$. The generating ideal of the wedge relations is given and the wedge space defined. Normal ordering of wedges is defined in terms of the energy function. Normally ordered wedges form a base of the wedge space. The q-deformed Fock space is defined as the space of semi-infinite wedges with a finite number of vectors in the wedge product differing from a ground state sequence, and endowed with a separated q-adic topology . Normally ordered wedges form a base of the Fock space. The action of $\\U_q(\\affsl{2})$ on the Fock space converges in the q-adic topology. On the Fock space the action of bosons, which commute with the $\\U_q(\\affsl{2})$-action, also converges in the q-adic topology. Hence follows the decomposition of the Fock space into irreducible $\\U_q(\\affsl{2})$-modules.

  17. The effects of various kinds of lateral wedge insoles on performance of individuals with knee joint osteoarthritis

    Directory of Open Access Journals (Sweden)

    Masoud Rafiaee

    2012-01-01

    Conclusion: Using lateral wedge insole is a simple, inexpensive therapy for decreasing pain and improving quality of life; however, most research must be carried out to find the effects of lateral wedge on severity of knee joint OA and aligning TFA.

  18. 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.

  19. Accuracy and initial stability of open- and closed-wedge high tibial osteotomy: a cadaveric RSA study.

    NARCIS (Netherlands)

    Gaasbeek, R.D.A.; Welsing, R.T.C.; Verdonschot, N.J.J.; Rijnberg, W.J.; Loon, C.J.M. van; Kampen, A. van

    2005-01-01

    We analyzed the difference in angle-correction accuracy and initial stability between open-wedge (OWO) and closed-wedge tibial valgus osteotomy (CWO). Five fresh-frozen pairs of human cadaver lower limbs were used; their bone mineral density (BMD) was measured with DEXA and a planned 7 degrees valgu

  20. Long range hybrid tube-wedge plasmonic waveguide with extreme light confinement and good fabrication error tolerance.

    Science.gov (United States)

    Ding, Li; Qin, Jin; Xu, Kai; Wang, Liang

    2016-02-22

    We studied a novel long range hybrid tube-wedge plasmonic (LRHTWP) waveguide consisting of a high index dielectric nanotube placed above a triangular metal wedge substrate. Using comprehensive numerical simulations on guiding properties of the designed waveguide, it is found that extreme light confinement and low propagation loss are obtained due to strong coupling between dielectric nanotube mode and wedge plasmon polariton. Comparing with previous studied hybrid plasmonic waveguides, the LRHTWP waveguide has longer propagation length and tighter mode confinement. In addition, the LRHTWP waveguide is quite tolerant to practical fabrication errors such as variation of the wedge tip angle and the horizontal misalignment between the nanotube and the metal wedge. The proposed LRHTWP waveguide could have many application potentials for various high performance nanophotonic components.

  1. The distribution and depth of ion doses implanted into wedges by plasma immersion ion implantation in drifting and stationary plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Tarrant, R N; Devasahayam, S; McKenzie, D R; Bilek, M M M [School of Physics (A28), University of Sydney, NSW 2006 (Australia)

    2006-08-15

    The distribution of ion dose arising from plasma immersion ion implantation (PIII) of a complex shape in the form of a wedge is measured. Two types of plasma are considered: a drifting titanium plasma derived from a pulsed cathodic arc and a stationary plasma generated by PIII pulses in oxygen or nitrogen gas. The distributions of the implanted material over the surface of the aluminium wedge were studied using secondary ion mass spectroscopy and Rutherford backscattering. The effects of varying the apex angles of the wedge and the plasma density are investigated. We conclude that ion-focusing effects at the apex of the wedge were more important for the drifting plasma than for the stationary plasmas. In a drifting plasma, the ion drift velocity directed towards the apex of the wedge compresses the sheath close to the apex and enhances the concentration of the dose. For the stationary plasma, the dose is more uniform.

  2. Effects of two different degrees of lateral-wedge insoles on unilateral lower extremity load-bearing line in patients with medial knee osteoarthritis

    Directory of Open Access Journals (Sweden)

    Bilge Yılmaz

    2016-08-01

    Conclusion: Both wedge insoles was effective in moving of the unilateral lower extremity load carrying line to the lateral. Lateral wedged insoles are biomechanically effective and reduce loading of the medial compartment in patients with medial knee osteoarthritis.

  3. Analysis on electromagnetic scattering by a wedge with impedance faces under exact impedance boundary

    Institute of Scientific and Technical Information of China (English)

    吴良超; 汪茂光

    1995-01-01

    Under the exact impedance boundary condition (EIBC), by using wave equations and the longitudinal field method, the electromagnetic scattenng by an impedance wedge has been analysed in detail, following the Maliuzhinets approach, and the uniform diffraction coefficient of the diffracted field has been presented.

  4. Estimation of treatment efficacy with complier average causal effects (CACE) in a randomized stepped wedge trial.

    Science.gov (United States)

    Gruber, Joshua S; Arnold, Benjamin F; Reygadas, Fermin; Hubbard, Alan E; Colford, John M

    2014-05-01

    Complier average causal effects (CACE) estimate the impact of an intervention among treatment compliers in randomized trials. Methods used to estimate CACE have been outlined for parallel-arm trials (e.g., using an instrumental variables (IV) estimator) but not for other randomized study designs. Here, we propose a method for estimating CACE in randomized stepped wedge trials, where experimental units cross over from control conditions to intervention conditions in a randomized sequence. We illustrate the approach with a cluster-randomized drinking water trial conducted in rural Mexico from 2009 to 2011. Additionally, we evaluated the plausibility of assumptions required to estimate CACE using the IV approach, which are testable in stepped wedge trials but not in parallel-arm trials. We observed small increases in the magnitude of CACE risk differences compared with intention-to-treat estimates for drinking water contamination (risk difference (RD) = -22% (95% confidence interval (CI): -33, -11) vs. RD = -19% (95% CI: -26, -12)) and diarrhea (RD = -0.8% (95% CI: -2.1, 0.4) vs. RD = -0.1% (95% CI: -1.1, 0.9)). Assumptions required for IV analysis were probably violated. Stepped wedge trials allow investigators to estimate CACE with an approach that avoids the stronger assumptions required for CACE estimation in parallel-arm trials. Inclusion of CACE estimates in stepped wedge trials with imperfect compliance could enhance reporting and interpretation of the results of such trials.

  5. Nanoscale guiding for cold atoms based on surface plasmons along the tips of metallic wedges

    Institute of Scientific and Technical Information of China (English)

    Wang Zheng-Ling; Tang Wei-Min; Zhou Ming; Gao Chuan-Yu

    2013-01-01

    We propose a novel scheme to guide neutral cold atoms in a nanoscale region based on surface plasmons (SPs) of one pair and two pairs of tips of metallic wedges with locally enhanced light intensity and sub-optical wavelength resolution.We analyze the near-field intensity distribution of the tip of the metallic wedge by the FDTD method,and study the total intensity as well as the total potential of optical potentials and van der Waals potentials for 87Rb atoms in the light field of one pair and two pairs of tips of metallic wedges.It shows that the total potentials of one pair and two pairs of tips of metallic wedges can generate a gravito-optical trap and a dark closed trap for nanoscale guiding of neutral cold atoms.Guided atoms can be cooled with efficient intensity-gradient Sisyphus cooling by blue-detuned light field.This provides an important step towards the generation of hybrid systems consisting of isolated atoms and solid devices.

  6. 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. Recen...

  7. Impingement of water droplets on wedges and diamond airfoils at supersonic speeds

    Science.gov (United States)

    Serafini, John S

    1953-01-01

    An analytical solution has been obtained for the equations of motion of water droplets impinging on a wedge in a two-dimensional supersonic flow field with a shock wave attached to the wedge. The closed-form solution yields analytical expressions for the equation of the droplet trajectory, the local rate of impingement and the impingement velocity at any point on the wedge surface, and the total rate of impingement. The analytical expressions are utilized to determine the impingement on the forward surfaces of diamond airfoils in supersonic flow fields with attached shock waves. The results presented include the following conditions: droplet diameters from 2 to 100 microns, pressure altitudes from sea level to 30,000 feet, free-stream static temperatures from 420 degrees to 460 degrees R. Also, free-stream Mach numbers from 1.1 to 2.0, semi-apex angles for the wedge from 1.14 degrees to 7.97 degrees, thickness-to-chord ratios for the diamond airfoil from 0.02 to 0.14, chord lengths from 1 to 20 feet, and angles of attack from zero to the inverse tangent of the airfoil thickness-to-chord ratio.

  8. Optical necklaces generated by the diffraction on a stack of dielectric wedges

    Energy Technology Data Exchange (ETDEWEB)

    Izdebskaya, Yana [Nonlinear Physics Centre, Research School of Physical Sciences and Engineering, Australian National University, Canberra ACT 0200 (Australia); Department of Physics, V.I. Vernandsky Taurida National University, Simferopol 95007, Crimea (Ukraine)], E-mail: yvi124@rsphysse.anu.edu.au

    2008-05-19

    We demonstrate that the regular ring-shaped arrays of Gaussian beams, or optical necklaces, can be generated using diffraction on a stack of dielectric wedges. A condition for self-similarity and structural stability of the beams has been derived and shows good comparison with experimental data.

  9. 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-optical di...

  10. On the shape of a droplet in a wedge: new insight from electrowetting

    NARCIS (Netherlands)

    Baratian, D.; Cavalli, A.; Ende, van den H.T.M.; Mugele, F.

    2015-01-01

    The equilibrium morphology of liquid drops exposed to geometric constraints can be rather complex. Even for simple geometries, analytical solutions are scarce. Here, we investigate the equilibrium shape and position of liquid drops confined in the wedge between two solid surfaces at an angle α. Usin

  11. Quantitative planar Raman imaging through a spectrograph: visualisation of a supersonic wedge flow

    NARCIS (Netherlands)

    Tolboom, R.A.L.; Dam, N.J.; Meulen, J.J. ter; Bakker, P.G.

    2005-01-01

    Planar Raman imaging through a spectrograph is demonstrated as a diagnostic tool for quantitative flow visualisation of internal supersonic wedge flow. A dedicated Bayesian deconvolution filter is used to remove the spectral structure that is introduced by the spectrograph. The 2D density field is d

  12. Fossil predation: did some clavilithine fasciolariid gastropods employ valve-wedging to feed on bivalves?

    NARCIS (Netherlands)

    Vermeij, Geerat J.

    2015-01-01

    Several gastropods, including members of the Busyconinae, wedge or chip bivalve prey by inserting the outer lip between the valves. This habit, which is associated with an abapically downwardly convex outer lip, often results in breakage and subsequent repair of the lip. I tested the hypothesis that

  13. Thick-Walled Cylinder Theory Applied on a Conical Wedge Anchorage

    DEFF Research Database (Denmark)

    Bennitz, Anders; Grip, Niklas; Schmidt, Jacob Wittrup

    2011-01-01

    Conical wedge anchorages are frequently used to anchor steel tendons in prestressing applications within the construction industry. To replace the steel tendons with non-corrosive and low weight FRPs (Fiber Reinforced Polymers), the different mechanical interactions between the steel and FRPs call...

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

    NARCIS (Netherlands)

    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.

    2013-01-01

    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 an

  15. A reciprocating ledge technique in closing wedge osteotomy for genu valgum in adolescents.

    Science.gov (United States)

    Dhar, Shabir Ahmed; Butt, Mohammed Farooq; Mir, Mohammed Ramzan; Dar, Tahir Ahmed; Sultan, Asif

    2009-12-01

    To describe a technique that preserves anterior and posterior alternate ledges in a closing wedge osteotomy. Five patients aged 14 to 19 years underwent a closing wedge osteotomy for genu valgum in 8 limbs using a reciprocating ledge technique. A unicortical wedge of bone was removed, with the anterior and posterior cortices spared. The anterior cortex at the proximal level and the posterior cortex at the distal level were cut through. With a wobbling action, the osteotomy site was rotated, and the distal fragment externally rotated. Manual force was applied to close the osteotomy site ensuring overlapping of the reciprocal ledges. The distal fragment was translated laterally to prevent club deformity. The osteotomy site was held with one or 2 staples. Stability was tested by flexion and extension of knee. All 8 limbs attained bone union within 12 weeks, and full range of motion within a mean of 13 (range, 12-15) weeks. The mean correction of the tibiofemoral angle was 13 degrees. At a mean follow-up of 12 months, all patients were pain-free and none developed club deformity. Sparing reciprocal ledges in a closing wedge osteotomy for genu valgum may increase stability in the flexion-extension axis, enable early range-of-motion exercises, and facilitate early bone union.

  16. Laterally wedged insoles in knee osteoarthritis: do biomechanical effects decline after one month of wear?

    Directory of Open Access Journals (Sweden)

    Bennell Kim L

    2009-11-01

    Full Text Available Abstract Objective This study aimed to determine whether the effect of laterally wedged insoles on the adduction moment in knee osteoarthritis (OA declined after one month of wear, and whether higher reported use of insoles was associated with a reduced effect on the adduction moment at one month. Methods Twenty people with medial compartment OA underwent gait analysis in their own shoes wearing i no insoles and; ii insoles wedged laterally 5° in random order. Testing occurred at baseline and after one month of use of the insoles. Participants recorded daily use of insoles in a log-book. Outcomes were the first and second peak external knee adduction moment and the adduction angular impulse, compared across conditions and time with repeated measures general linear models. Correlations were obtained between total insole use and change in gait parameters with used insoles at one month, and change scores were compared between high and low users of insoles using general linear models. Results There was a significant main effect for condition, whereby insoles significantly reduced the adduction moment (all p Conclusion Effects of laterally wedged insoles on the adduction moment do not appear to decline after one month of continuous use, suggesting that significant wedge degradation does not occur over the short-term.

  17. 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.

  18. Some Historical Treatments should not be Forgotten: A Review of Cast Wedging and A Trick to Normalize Non-Standardized Digital X-rays

    OpenAIRE

    2014-01-01

    Introduction: Cast wedging is a simple and reproducible method of manipulating a sub-optimally reduced fracture producing a correction and a final alignment that is amenable to definitive closed treatment. Multiple successful techniques have been previously described in the literature (opening wedge, closing wedge and combination). Technical Note: We present a simple reproducible method of templating and executing a proper cast wedging technique using digital imaging systems that are not cont...

  19. Three Years of High Resolution Year-Round Monitoring of Ice-Wedge Thermal Contraction Cracking in Svalbard

    Science.gov (United States)

    Christiansen, H. H.

    2006-12-01

    Most likely ice-wedges are the most widespread periglacial landform in lowlands with continuous permafrost. With a changing climate it is important to understand better the geomorphological processes controlling ice- wedge growth and decay, as they might cause large changes to the surface of the landscape, particularly if the active layer thickness increases causing melting of the most ice-rich permafrost top layer. As most settlements on permafrost are located in lowland areas, ice-wedge formation can also influence the infrastructure. Understanding the processes of ice-wedge growth and their thaw transformation into ice-wedge casts are essential when using contemporary ice wedges as analogues of Pleistocene thermal contraction cracking in palaeoenvironmental reconstructions. As ice-wedges are largely controlled by winter conditions, improved understanding of the factors controlling their growth will enable better palaeoclimatic reconstructions both directly from ice-wedges, but also from ice-wedge casts, than just mean winter temperatures. Detailed studies of ice-wedge dynamics, including quantification of movement, have only been done in very few places in the Arctic. In high arctic Svalbard at 78°N climate at sea level locates these islands close to the southern limit of the continuous permafrost zone, with MAAT of as much as -4 to -6°C. However, thermal contraction cracking is demonstrated to be widespread in the Adventdalen study area in Svalbard. The year-round field access from the University Centre in Svalbard, UNIS, has enabled the collection of different continuous or high frequency ice-wedge process monitoring data since 2002 to improve the understanding of the geomorphological activity of this landform. In all the winters the air temperature was below -30°C for shorter or longer periods. During all the winters, the temperature in the top permafrost was below -15°C both in the ice-wedge top for shorter or longer periods. The snow cover was

  20. Crustal and Fault Strengths from Critical Taper Measurements: Insights into the behavior of Accretionary Wedges using Distinct-Element Models

    Science.gov (United States)

    Strayer, L.; Suppe, J.

    2012-12-01

    It is increasingly clear that many major faults are weak relative to quasistatic friction because of dynamical effects involving the microprocesses of high-velocity friction and the energetics of large-scale fault rupture. Even at the toes of accretionary wedges where velocity strengthening is expected, large displacements can occur dynamically. We seek to better understand the relationship between the large-scale strength of such faults and of the crust containing them over a timescale much greater than seismic cycles. Critical-taper theory provides straightforward quantitative relationships between accretionary wedge geometry and absolute basal fault and wedge strengths with minimal assumptions. Wedge tapers constrain the far-field stresses under which detachments slip and wedges grow during wedge-growing events, whether they are dynamical or quasistatic. To date most applications of wedge mechanics to accretionary wedges involve analog and numerical modeling with largely conceptual insight, for example illuminating the role of geological heterogeneity. Here we demonstrate that recent theoretical advances that are successful in extracting absolute wedge and detachment strengths from the geometry of active wedges can also be applied to extract large-scale strengths in distinct element numerical models in both mechanically homogeneous and heterogeneous wedges. The distinct element method (DEM) is an ideal tool for the study and modeling of critical taper wedges: model wedges can be initially cohesive (bonded) or cohesionless. Faults and folds form naturally as the result of progressive bond breakage during shortening and wedge growth. Heterogeneity can be introduced by creating layered groups of particles of differing mechanical properties. The DEM suffers to some extent in that macro material properties cannot be directly prescribed but rather must be defined by a modest number of micro-properties and the process in necessarily iterative and developing a wide

  1. Complex interactions between diapirs and 4-D subduction driven mantle wedge circulation.

    Science.gov (United States)

    Sylvia, R. T.; Kincaid, C. R.

    2015-12-01

    Analogue laboratory experiments generate 4-D flow of mantle wedge fluid and capture the evolution of buoyant mesoscale diapirs. The mantle is modeled with viscous glucose syrup with an Arrhenius type temperature dependent viscosity. To characterize diapir evolution we experiment with a variety of fluids injected from multiple point sources. Diapirs interact with kinematically induced flow fields forced by subducting plate motions replicating a range of styles observed in dynamic subduction models (e.g., rollback, steepening, gaps). Data is collected using high definition timelapse photography and quantified using image velocimetry techniques. While many studies assume direct vertical connections between the volcanic arc and the deeper mantle source region, our experiments demonstrate the difficulty of creating near vertical conduits. Results highlight extreme curvature of diapir rise paths. Trench-normal deflection occurs as diapirs are advected downward away from the trench before ascending into wedge apex directed return flow. Trench parallel deflections up to 75% of trench length are seen in all cases, exacerbated by complex geometry and rollback motion. Interdiapir interaction is also important; upwellings with similar trajectory coalesce and rapidly accelerate. Moreover, we observe a new mode of interaction whereby recycled diapir material is drawn down along the slab surface and then initiates rapid fluid migration updip along the slab-wedge interface. Variability in trajectory and residence time leads to complex petrologic inferences. Material from disparate source regions can surface at the same location, mix in the wedge, or become fully entrained in creeping flow adding heterogeneity to the mantle. Active diapirism or any other vertical fluid flux mechanism employing rheological weakening lowers viscosity in the recycling mantle wedge affecting both solid and fluid flow characteristics. Many interesting and insightful results have been presented based

  2. Late Holocene stable-isotope based winter temperature records from ice wedges in the Northeast Siberian Arctic

    Science.gov (United States)

    Opel, Thomas; Meyer, Hanno; Laepple, Thomas; Dereviagin, Alexander Yu.

    2016-04-01

    The Arctic is currently undergoing an unprecedented warming. This highly dynamic response on changes in climate forcing and the global impact of the Arctic water, carbon and energy balances make the Arctic a key region to study past, recent and future climate changes. Recent proxy-based temperature reconstructions indicate a long-term cooling over the past about 8 millennia that is mainly related to a decrease in solar summer insolation and has been reversed only by the ongoing warming. Climate model results on the other hand show no significant change or even a slight warming over this period. This model-proxy data mismatch might be caused by a summer bias of the used climate proxies. Ice wedges may provide essential information on past winter temperatures for a comprehensive seasonal picture of Holocene Arctic climate variability. Polygonal ice wedges are a widespread permafrost feature in the Arctic tundra lowlands. Ice wedges form by the repeated filling of thermal contraction cracks with snow melt water, which quickly refreezes at subzero ground temperatures and forms ice veins. As the seasonality of frost cracking and infill is generally related to winter and spring, respectively, the isotopic composition of wedge ice is indicative of past climate conditions during the annual cold season (DJFMAM, hereafter referred to as winter). δ18O of ice is interpreted as proxy for regional surface air temperature. AMS radiocarbon dating of organic remains in ice-wedge samples provides age information to generate chronologies for single ice wedges as well as regionally stacked records with an up to centennial resolution. In this contribution we seek to summarize Holocene ice-wedge δ18O based temperature information from the Northeast Siberian Arctic. We strongly focus on own work in the Laptev Sea region but consider as well literature data from other regional study sites. We consider the stable-isotope composition of wedge ice, ice-wedge dating and chronological

  3. Stable isotope and gas properties of two ice wedges from Cape Mamontov Klyk, Laptev Sea, Northern Siberia

    Directory of Open Access Journals (Sweden)

    T. Boereboom

    2011-12-01

    Full Text Available This paper presents and discusses the texture, fabric and gas properties (contents of total gas, O2, N2, CO2, and CH4 of two ice wedges from Cape Mamontov Klyk, Laptev Sea, 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 its sides (referred to as ice-sand wedge. A comparison of gas properties, crystal size, fabrics and stable isotope data (δ18O and δD allows discriminating between three different facies of ice with specific paleoenvironmental signatures, suggesting different climatic conditions and rates of biological activity. More specifically, total gas content and composition reveal variable intensities of meltwater infiltration and show the impact of biological processes with contrasting contributions from anaerobic and aerobic conditions. Stable isotope data are shown to be valid for discussing changes in paleoenvironmental conditions and/or decipher different sources for the snow feeding into the ice wedges with time. Our data also give support to the previous assumption that the composite ice wedge was formed in Pleistocene and the ice wedge in Holocene times. This study sheds more light on the conditions of ice wedge growth under changing environmental conditions.

  4. Orthotic Heel Wedges Do Not Alter Hindfoot Kinematics and Achilles Tendon Force During Level and Inclined Walking in Healthy Individuals.

    Science.gov (United States)

    Weinert-Aplin, Robert A; Bull, Anthony M J; McGregor, Alison H

    2016-04-01

    Conservative treatments such as in-shoe orthotic heel wedges to treat musculoskeletal injuries are not new. However, weak evidence supporting their use in the management of Achilles tendonitis suggests the mechanism by which these heel wedges works remains poorly understood. It was the aim of this study to test the underlying hypothesis that heel wedges can reduce Achilles tendon load. A musculoskeletal modeling approach was used to quantify changes in lower limb mechanics when walking due to the introduction of 12-mm orthotic heel wedges. Nineteen healthy volunteers walked on an inclinable walkway while optical motion, force plate, and plantar pressure data were recorded. Walking with heel wedges increased ankle dorsiflexion moments and reduced plantar flexion moments; this resulted in increased peak ankle dorsiflexor muscle forces during early stance and reduced tibialis posterior and toe flexor muscle forces during late stance. Heel wedges did not reduce overall Achilles tendon force during any walking condition, but did redistribute load from the medial to lateral triceps surae during inclined walking. These results add to the body of clinical evidence confirming that heel wedges do not reduce Achilles tendon load and our findings provide an explanation as to why this may be the case.

  5. Differential wedging of vertebral body and intervertebral disc in thoracic and lumbar spine in adolescent idiopathic scoliosis – A cross sectional study in 150 patients

    Directory of Open Access Journals (Sweden)

    Kim Hak-Jun

    2008-08-01

    Full Text Available Abstract Background Hueter-Volkmann's law regarding growth modulation suggests that increased pressure on the end plate of bone retards the growth (Hueter and conversely, reduced pressure accelerates the growth (Volkmann. Literature described the same principle in Rat-tail model. Human spine and its deformity i.e. scoliosis has also same kind of pattern during the growth period which causes wedging in disc or vertebral body. Methods This cross sectional study in 150 patients of adolescent idiopathic scoliosis was done to evaluate vertebral body and disc wedging in scoliosis and to compare the extent of differential wedging of body and disc, in thoracic and lumbar area. We measured wedging of vertebral bodies and discs, along with two adjacent vertebrae and disc, above and below the apex and evaluated them according to severity of curve (curve 30° to find the relationship of vertebral body or disc wedging with scoliosis in thoracic and lumbar spine. We also compared the wedging and rotations of vertebrae. Results In both thoracic and lumbar curves, we found that greater the degree of scoliosis, greater the wedging in both disc and body and the degree of wedging was more at apex supporting the theory of growth retardation in stress concentration area. However, the degree of wedging in vertebral body is more than the disc in thoracic spine while the wedging was more in disc than body in lumbar spine. On comparing the wedging with the rotation, we did not find any significant relationship suggesting that it has no relation with rotation. Conclusion From our study, we can conclude that wedging in disc and body are increasing with progression on scoliosis and maximum at apex; however there is differential wedging of body and disc, in thoracic and lumbar area, that is vertebral body wedging is more profound in thoracic area while disc wedging is more profound in lumbar area which possibly form 'vicious cycle' by asymmetric loading to spine for the

  6. Short- and long-term deformation and the earthquake cycle in the southern Bolivia Subandes: Implications for orogenic wedge processes

    Science.gov (United States)

    Brooks, B. A.; Bevis, M. G.; Whipple, K. X.; Kendrick, E. C.; Smalley, R.; Arrowsmith, R.; Zapata, T.

    2009-12-01

    In the context of critical taper wedge mechanics, we analyze a new GPS-derived surface velocity field from the southern Subandean (SSA) range on the east flank of the central Andean Plateau. The SSA is one of the few active orogenic wedges located far enough from a plate boundary so that the geodetic signature of contractional processes may be isolated. We observe and model a strong strike-perpendicular surface velocity gradient as arising from the change in frictional behaviour of the SSA basal decollement from freely slipping to locked. The estimated width of the locked zone is ~130 km, a value that is significantly larger than in other similar wedges in Nepal or Taiwan and implies the SSA thrust front could host great (larger than M 8) intraplate thrust earthquakes. In support of this, topographic data (individual scarps and landslide scars) are consistent with the surface expression of the ~500 km long Mandeyepecua thrust fault resulting from large earthquake ruptures with long recurrence intervals. In comparison to other similar wedges (the northern Subandes, Nepal, and Taiwan) precipitation rates in the SSA are significantly lower and thus a wider orogenic wedge width is predicted by critical taper theory. We explore the hypothesis that the geodetically-determined width is equivalent to the orogenic wedge width by using earthquake scaling relations for individual faults and surface displacements predicted from decollement ruptures to model the velocity profile derived from published, sequentially restored balanced cross-sections in the region. Our work provides two new important insights on the interaction between climate and tectonics in orogenic wedges: 1) a drier climate favours increased size of potential thrust-front earthquakes by permitting the width of the active wedge to increase; 2) frictional variations on a decollement may be spatially persistent over geologic time-scales and so should be taken into account in surface process models of orogenic

  7. .Gov Domains API

    Data.gov (United States)

    General Services Administration — This dataset offers the list of all .gov domains, including state, local, and tribal .gov domains. It does not include .mil domains, or other federal domains outside...

  8. Hydrodynamic controls on oxygen dynamics in a riverine salt wedge estuary, the Yarra River estuary, Australia

    Science.gov (United States)

    Bruce, L. C.; Cook, P. L. M.; Teakle, I.; Hipsey, M. R.

    2014-04-01

    Oxygen depletion in coastal and estuarine waters has been increasing rapidly around the globe over the past several decades, leading to decline in water quality and ecological health. In this study we apply a numerical model to understand how salt wedge dynamics, changes in river flow and temperature together control oxygen depletion in a micro-tidal riverine estuary, the Yarra River estuary, Australia. Coupled physical-biogeochemical models have been previously applied to study how hydrodynamics impact upon seasonal hypoxia; however, their application to relatively shallow, narrow riverine estuaries with highly transient patterns of river inputs and sporadic periods of oxygen depletion has remained challenging, largely due to difficulty in accurately simulating salt wedge dynamics in morphologically complex areas. In this study we overcome this issue through application of a flexible mesh 3-D hydrodynamic-biogeochemical model in order to predict the extent of salt wedge intrusion and consequent patterns of oxygen depletion. The extent of the salt wedge responded quickly to the sporadic riverine flows, with the strength of stratification and vertical density gradients heavily influenced by morphological features corresponding to shallow points in regions of tight curvature ("horseshoe" bends). The spatiotemporal patterns of stratification led to the emergence of two "hot spots" of anoxia, the first downstream of a shallow region of tight curvature and the second downstream of a sill. Whilst these areas corresponded to regions of intense stratification, it was found that antecedent conditions related to the placement of the salt wedge played a major role in the recovery of anoxic regions following episodic high flow events. Furthermore, whilst a threshold salt wedge intrusion was a requirement for oxygen depletion, analysis of the results allowed us to quantify the effect of temperature in determining the overall severity and extent of hypoxia and anoxia. Climate

  9. Subsurface Thermal Erosion Of Ice-Wedge Polygon Terrains: Implications For Arctic Geosystem In Transition

    Science.gov (United States)

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

    2014-12-01

    Subsurface thermal erosion is triggered by convective heat transfers between flowing water and permafrost. For inland ice-wedge polygon terrains, 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 along exposed permafrost 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 and carbon within the permafrost geosystem. Exportation of sediments by fluvial processes within gullies are positive mechanical feed-back effects that keep gully channels active over decades. Along gully margins, drainage of disturbed polygons and ponds, slope drainage, soil consolidation, plant colonization of disturbed gully slopes and wet to mesic plant succession of drained polygons 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 mapped and 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 a numerical, fully-coupled, heat and mass (water) transfer model of ice-wedge thermal erosion. We used data collected over 10 years of geomorphological gully monitoring, regional climate scenarios, our physics-based numerical thermal erosion model and our field

  10. Some Historical Treatments should not be Forgotten: A Review of Cast Wedging and A Trick to Normalize Non-Standardized Digital X-rays

    Science.gov (United States)

    Jacobson, Nathan A.; Lee, Christopher L.

    2014-01-01

    Introduction: Cast wedging is a simple and reproducible method of manipulating a sub-optimally reduced fracture producing a correction and a final alignment that is amenable to definitive closed treatment. Multiple successful techniques have been previously described in the literature (opening wedge, closing wedge and combination). Technical Note: We present a simple reproducible method of templating and executing a proper cast wedging technique using digital imaging systems that are not controlled for magnification with an illustrative case. Conclusion: Renewed interest in cast wedging can provide a cost effective treatment with proven clinical outcomes in an ever changing and uncertain reimbursement climate. PMID:27298956

  11. 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.

  12. A Numerical Study on the Asymmetric Water Entry of A Wedge Section

    Institute of Scientific and Technical Information of China (English)

    M. S. Seif; S. M. Mousaviraad; S. H. Saddathosseini

    2004-01-01

    The effect of the asymmetric water entry over a submerged part of a ship on the hydrodynamic impact is investigated numerically. A wedge body is considered and the problem is assumed to be two-dimensional. The results of symmetric and asymmetric impacts are compared. The effect is found significant in the numerical simulation. The maximum hydrodynamic pressure at a heel angle of 10 degrees becomes about 95% more than that of the symmetric entry. The result of the present work proves the importance of asymmetrical hydrodynamic impact loading for structural design of a ship. Besides, the numerical procedure is not limited to a wedge type cross section and it is possible to apply it for any real geometry of ships and high-speed craft.

  13. 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.

  14. Plasmonic angular momentum on metal-dielectric nano-wedges in a sectorial indefinite metamaterial

    CERN Document Server

    Jin, Dafei

    2013-01-01

    We present an analytical study to the structure-modulated plasmonic angular momentum trapped on periodic metal-dielectric nano-wedges in the core region of a sectorial indefinite metamaterial. Employing a transfer-matrix calculation and a conformal-mapping technique, our theory is capable of dealing with realistic configurations of arbitrary sector numbers and rounded wedge tips. We demonstrate that in the deep-subwavelength regime strong electric field carrying high azimuthal variation can exist within only ten-nanometer length scale close to the structural center, and is naturally bounded by a characteristic radius of the order of hundred-nanometer away from the center. These extreme confining properties suggest that the structure under investigation may be superior to the conventional metal-dielectric waveguides or cavities in terms of nanoscale photonic manipulation.

  15. 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 phase equilibria, melt compositions, and reaction coefficients provide a framework for understanding how melt-wall rock reaction occurs in the natural system during melt ascent in the mantle wedge.

  16. 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.

  17. Wedge excision of the nail fold in the treatment of ingrown toenail.

    Science.gov (United States)

    Persichetti, Paolo; Simone, Pierfranco; Li Vecchi, Giancarlo; Di Lella, Filippo; Cagli, Barbara; Marangi, Giovanni Francesco

    2004-06-01

    Many treatment modalities of ingrown toenail are reported in the literature, often associated with unacceptably high recurrence rate. The authors present their technique, which aims at reducing the convexity of the nail fold. After complete removal of the nail plate and accurate debridement of the granulomatous tissue, a wedge-shaped ellipsis of skin and subcutaneous tissue, lateral to the affected nail fold, is removed. Approximation of the margins of the resulting defect determines eversion of the nail fold. One hundred twenty ingrown toenails were treated with the wedge excision of the nail fold at the outpatient clinic of the department of plastic surgery, Campus Bio-Medico University, Rome, Italy, between January 1998 and January 2002. Six recurrences were observed. In addition to the high cure rate, short postoperative pain duration, and morbidity as well as low risk of postoperative infection, the remarkable esthetic results achievable with this method are indicated.

  18. Structural control of the Gagua "Wedge" Zone east of Taiwan Island on the southern Okinawa Trough

    Institute of Scientific and Technical Information of China (English)

    ZHENG Yanpeng; LIU Baohua; WU Jinlong; LIANG Ruicai; LIU Chenguang; ZHANG Zhengmin

    2005-01-01

    Based on compositive analysis and interpretation of the observed and historical data, the geophysical field characters and structural properties of the Gagua "Wedge" Zone of the sea area east of Taiwan Island and the primary tectonic stress direction and its variabilities of backarc spreading in the southern Okinawa Trough are studied. It is concluded from the study results that the Gagua "Wedge" Zone is structurally consistent with the Gagua ridge and two fault basins on both sides of the Gagua ridge, and adjusts the moving direction and distance of the western Philippine Sea plate to make the northwestward motion of the plate on its east side change to the northward subduction of the plate on its west side so that the primary tectonic stress direction of the Okinawa Trough changed from NW-SE to nearly N-S, which provided the stress source for the Okinawa Trough to enter the second spreading stage.

  19. 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.

  20. Heat Transfer Analysis of MHD Water Functionalized Carbon Nanotube Flow over a Static/Moving Wedge

    Directory of Open Access Journals (Sweden)

    Waqar A. Khan

    2015-01-01

    Full Text Available The MHD flow and heat transfer from water functionalized CNTs over a static/moving wedge are studied numerically. Thermal conductivity and viscosity of both single and multiple wall carbon nanotubes (CNTs within a base fluid (water of similar volume are investigated to determine the impact of these properties on thermofluid performance. The governing partial differential equations are converted into nonlinear, ordinary, and coupled differential equations and are solved using an implicit finite difference method with quasi-linearization techniques. The effects of volume fraction of CNTs and magnetic and wedge parameters are investigated and presented graphically. The numerical results are compared with the published data and are found to be in good agreement. It is shown that the magnetic field reduces boundary layer thickness and increases skin friction and Nusselt numbers. Due to higher density and thermal conductivity, SWCNTs offer higher skin friction and Nusselt numbers.

  1. Direct Preparation of Nano-Quasicrystals via a Water-Cooled Wedge-Shaped Copper Mould

    Directory of Open Access Journals (Sweden)

    Zhifeng Wang

    2012-01-01

    Full Text Available We have successfully synthesized multicomponent Mg-based nano-quasicrystals (nano-QCs through a simple route by using a water-cooled wedge-shaped copper mould. Nanoscale QCs are prepared directly on tip of wedge-shaped castings. The further study shows that nano-QCs in the Mg71Zn26Y2Cu1 alloy show well microhardness of greater than HV450. Electrochemical properties of three kinds of quasicrystal alloys are investigated in simulated seawater. The Mg71Zn26Y2Cu1 nano-QC alloy presents the best corrosion resistance in this study for the formation of well-distributed nano-QC phases (1~5 nm and polygonal Mg2(Cu,Y nanophases (40~50 nm.

  2. On the shape of a droplet in a wedge: new insight from electrowetting.

    Science.gov (United States)

    Baratian, D; Cavalli, A; van den Ende, D; Mugele, F

    2015-10-21

    The equilibrium morphology of liquid drops exposed to geometric constraints can be rather complex. Even for simple geometries, analytical solutions are scarce. Here, we investigate the equilibrium shape and position of liquid drops confined in the wedge between two solid surfaces at an angle α. Using electrowetting, we control the contact angle and thereby manipulate the shape and the equilibrium position of aqueous drops in ambient oil. In the absence of contact angle hysteresis and buoyancy, we find that the equilibrium shape is given by a truncated sphere, at a position that is determined by the drop volume and the contact angle. At this position, the net normal force between drop and the surfaces vanishes. The effect of buoyancy gives rise to substantial deviations from this equilibrium configuration which we discuss here as well. We eventually show how the geometric constraint and electrowetting can be used to position droplets inside a wedge in a controlled way, without mechanical actuation.

  3. Soil carbon sequestration is a climate stabilization wedge: comments on Sommer and Bossio (2014).

    Science.gov (United States)

    Lassaletta, Luis; Aguilera, Eduardo

    2015-04-15

    Sommer and Bossio (2014) model the potential soil organic carbon (SOC) sequestration in agricultural soils (croplands and grasslands) during the next 87 years, concluding that this process cannot be considered as a climate stabilization wedge. We argue, however, that the amounts of SOC potentially sequestered in both scenarios (pessimistic and optimistic) fulfil the requirements for being considered as wedge because in both cases at least 25 GtC would be sequestered during the next 50 years. We consider that it is precisely in the near future, and meanwhile other solutions are developed, when this stabilization effort is most urgent even if after some decades the sequestration rate is significantly reduced. Indirect effects of SOC sequestration on mitigation could reinforce the potential of this solution. We conclude that the sequestration of organic carbon in agricultural soils as a climate change mitigation tool still deserves important attention for scientists, managers and policy makers.

  4. 用楔子撬开问题%Using a Wedge to Pry Open a Problem

    Institute of Scientific and Technical Information of China (English)

    马提索夫

    2001-01-01

    When I elicited the Pumi word ts6 'wedge' in Kunming (March 1996), I was struck by its resemblance to Lahu jfl 'wedge'. Since the Qiangic languages are not particularly close to Loloish on the TB family tree,this apparent cognate for an item of non-core vocabulary was of interest. The first task in establishing a relationship between the Pumi and the Lahu forms was to reconstruct the PLB ancestor of Lahu jfi. Then possible cognates to the Pumi form in other Qiangic languages had to be examined.Given our present rudimentary knowledge of comparative Qiangic,could parallel examples establish a Proto-Qiangic reconstruction resembling our newly reconstructed PLB form?

  5. Behavior of the Siemens Virtual Wedge following an interruption to beam delivery.

    Science.gov (United States)

    Richmond, N D; Walker, C P

    2003-01-01

    Investigations were made into the beam profile shape and dose delivered by the Siemens Virtual Wedge trade mark under standard operational conditions compared with those following delivery interruption on two Siemens Primus linear accelerators (Type 7445 and 8067) running different versions of control software (7.2 and 7.0, respectively). The shape of the Virtual Wedge trade mark profiles was found to be unaffected by beam delivery interruption. An increase in the dose delivered to the central axis was found when delivery was interrupted and subsequently resumed using information recorded in a recall data file on one of the accelerators. This dose increase was attributed to a difference in delivered monitor units recorded in the recall data file compared to those displayed on the linear accelerator control console.

  6. Large negative Goos-H(a)nchen shift from a wedge-shaped thin film

    Institute of Scientific and Technical Information of China (English)

    Jianping Bai; Yaoju Zhang

    2009-01-01

    The analytical expression for the complex amplitude of light reflected from a wedge-shaped thin film is derived.For plane wave incidence,a simple ray tracing approach is used to calculate Goos-H(a)nchen(GH)shifts;and for non-plane wave incidence,for example,a Gaussian beam,the angular spectrum approach of plane wave is used in simulation.The two approaches predict that a wedge-shaped thin film can produce large negative longitudinal GH shifts.Although the reflectivity is small near the condition of resonance,the large negative GH shifts can be more easily detected in comparison with the shift from a plane-paxallel film in vacuum.

  7. Effect of ultrasonic power on wedge bonding strength and interface microstructure

    Institute of Scientific and Technical Information of China (English)

    WANG Fu-liang; LI Jun-hui; HAN Lei; ZHONG Jue

    2007-01-01

    During the aluminum wire wedge bonding, the ultrasonic power and bonding strength were obtained. Based on those data, the relationship between ultrasonic power and bonding strength was studied. The results show that: 1) ultrasonic power is affected by ultrasonic power ratio and other uncontrolled factors such as asymmetric substrate quality, unstable restriction on the interface between wedge tool and aluminum wire; 2) when ultrasonic power is less than 1.0 W, increasing ultrasonic power leads to increasing bonding strength and decreasing failure bonding; on the contrary, when ultrasonic power is greater than 1.6 W, increasing power leads to decreasing bonding strength and increasing failure bonding; 3) only when ultrasonic power is between 1.0 W and 1.6 W, can stable and high yield bonding be reached. Finally, the microstructure of bonding interface was observed, and a ring-shaped bond pattern is founded in the center and friction scrape besides the ring area.

  8. Analytic Study of Magnetohydrodynamic Flow and Boundary Layer Control Over a Wedge

    Institute of Scientific and Technical Information of China (English)

    M. Chandrasekar; S. Baskaran

    2008-01-01

    A genuine variational principle developed by Gyarmati, in the field of thermodynamics of irreversible processes unifying the theoretical requirements of technical, environmental and biological sciences is employed to study the effects of uniform suction and injection on MHD flow adjacent to an isothermal wedge with pressure gradient in the presence of a transverse magnetic field. The velocity distribution inside the boundary layer has been considered as a simple polynomial function and the variational principle is formulated. The Euler-Lagrange equation is reduced to a simple polynomial equation in terms of momentum boundary layer thickness. The velocity profiles, displacement thickness and the coefficient of skin friction are calculated for various values of wedge angle parameter m, magnetic parameter ε and suction/injection parameter H. The present results are compared with known available results and the comparison is found to be satisfactory. The present study establishes high accuracy of results obtained by this variational technique.

  9. 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 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.

  10. A Single Photon Imaging System Based on Wedge and Strip Anodes

    Institute of Scientific and Technical Information of China (English)

    MIAO Zhen-Hua; ZHAO Bao-Sheng; ZHANG Xing-Hua; LIU Yong-An

    2008-01-01

    A new prototype of single photon imaging system based on wedge and strip anodes is developed. The prototype can directly measure the intensity and position information for an ultra-weak radiant source which takes on the character of single photons. The image of the ultra-weak radiant source can be reconstructed with a wedge and strip anodes detector and an electronic readout subsystem by photon counting and photon position sensitive detecting in a period of time. With proper evaluation, the prototype reveals a spatial resolution superior to 150μm, a 66-kHz maximal counting rate and a dark-count below 0.67count/cm2s.

  11. Combined effect of tobacco smoking and alcohol drinking in the risk of head and neck cancers: a re-analysis of case-control studies using bi-dimensional spline models.

    Science.gov (United States)

    Dal Maso, Luigino; Torelli, Nicola; Biancotto, Elisa; Di Maso, Matteo; Gini, Andrea; Franchin, Gianni; Levi, Fabio; La Vecchia, Carlo; Serraino, Diego; Polesel, Jerry

    2016-04-01

    The synergistic effect of tobacco smoking and alcohol consumption on the risk of head and neck cancers has been mainly investigated as a cross-product of categorical exposure, thus leading to loss of information. We propose a bi-dimensional logistic spline model to investigate the interacting dose-response relationship of two continuous exposures (i.e., ethanol intake and tobacco smoking) on the risk of head and neck cancers, representing results through three-dimensional graphs. This model was applied to a pool of hospital-based case-control studies on head and neck cancers conducted in Italy and in the Vaud Swiss Canton between 1982 and 2000, including 1569 cases and 3147 controls. Among never drinkers and for all levels of ethanol intake, the risk of head and neck cancers steeply increased with increasing smoking intensity, starting from 1 cigarette/day. The risk associated to ethanol intake increased with incrementing exposure among smokers, and a threshold effect at approximately 50 g/day emerged among never smokers. Compared to abstainers from both tobacco and alcohol consumption, the combined exposure to ethanol and/or cigarettes led to a steep increase of cancer risk up to a 35-fold higher risk (95 % confidence interval 27.30-43.61) among people consuming 84 g/day of ethanol and 10 cigarettes/day. The highest risk was observed at the highest levels of alcohol and tobacco consumption. Our findings confirmed a combined effect of tobacco smoking and alcohol drinking on head and neck cancers risk, providing evidence that bi-dimensional spline models could be a feasible and flexible method to explore the pattern of risks associated to two interacting continuous-exposure variables.

  12. Evolution of Landau levels in graphene-based topological insulators in the presence of wedge disclinations

    CERN Document Server

    Oliveira, J R S; Furtado, C; Sergeenkov, S

    2016-01-01

    In this paper we consider modification of electronic properties of graphene-based topological insulator in the presence of wedge disclination and magnetic field by adopting the Kane-Mele model with intrinsic spin-orbit coupling. Using the properly defined Dirac-Weyl equation for this system, an exact solution for the Landau levels is obtained. The influence of the topological defect on the evolution of Landau levels is discussed.

  13. 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.

  14. Margin Distance Does Not Influence Recurrence and Survival After Wedge Resection for Lung Cancer.

    Science.gov (United States)

    Maurizi, Giulio; D'Andrilli, Antonio; Ciccone, Anna Maria; Ibrahim, Mohsen; Andreetti, Claudio; Tierno, Simone; Poggi, Camilla; Menna, Cecilia; Venuta, Federico; Rendina, Erino Angelo

    2015-09-01

    The relationship between the free margin distance and the recurrence rate and overall survival after R0 wedge resection for non-small cell lung cancer (NSCLC) is still not clear. We retrospectively evaluated the long-term oncologic outcome of patients who had undergone wedge resection for NSCLC to assess the prognostic effect of margin distance in this setting. Between 2003 and 2013, 243 consecutive patients with a functional contraindication to major lung resection underwent wedge resection with systematic lymph node dissection for clinical stage I NSCLC. The study enrolled 182 patients with pathologic stage I and R0 resection and divided them into three subgroups according to margin distance of less than 1 cm (n = 30), 1 to 2 cm (n = 80), and more than 2 cm (n = 72). The histologic assessment was adenocarcinoma in 112 patients, squamous cell in 30, and other in 40. Postoperative morbidity was 18.7%, and postoperative mortality was 1.1%. The median follow-up was 31 months (range, 2 to 133 months). The locoregional (lung parenchyma, hilum, mediastinum) recurrence rate was 26.4% (n = 48). The distant recurrence rate was 11% (n = 20). Overall 5-year survival was 70.4%. Disease-free 5-year survival was 51.7%. There was no statistical difference in locoregional (p = 0.9) and distant (p = 0.3) recurrence rate and no difference in overall survival (p = 0.07) when the three groups were compared. Wedge resection is a viable option for the surgical treatment of stage I NSCLC when lobectomy is contraindicated. The distance between the tumor and the parenchymal suture margin does not influence recurrence or the survival rate when an R0 resection is achieved. Copyright © 2015 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.

  15. A Concise UTD Formulation for the Scattering by a Wedge with Impedance Faces

    Institute of Scientific and Technical Information of China (English)

    YUAN Fei; ZHU Guo-qiang

    2004-01-01

    A concise formulation of the uniform geometrical theory of diffraction (UTD) solution for the scattering by a wedge with isotropic impedance faces at a plane wave normally incident case is deduced in this paper, which inherits the uniformity of the original result. It overcomes the complexity of the former, expresses clearly physical meanings, and is very prone to calculation with computer. The numerical results agree well with those given by published papers.

  16. Supersonic flow onto solid wedges, multidimensional shock waves and free boundary problems

    Science.gov (United States)

    Chen, Gui-Qiang

    2017-08-01

    When an upstream steady uniform supersonic flow impinges onto a symmetric straight-sided wedge, governed by the Euler equations, there are two possible steady oblique shock configurations if the wedge angle is less than the detachment angle -- the steady weak shock with supersonic or subsonic downstream flow (determined by the wedge angle that is less or larger than the sonic angle) and the steady strong shock with subsonic downstream flow, both of which satisfy the entropy condition. The fundamental issue -- whether one or both of the steady weak and strong shocks are physically admissible solutions -- has been vigorously debated over the past eight decades. In this paper, we survey some recent developments on the stability analysis of the steady shock solutions in both the steady and dynamic regimes. For the static stability, we first show how the stability problem can be formulated as an initial-boundary value type problem and then reformulate it into a free boundary problem when the perturbation of both the upstream steady supersonic flow and the wedge boundary are suitably regular and small, and we finally present some recent results on the static stability of the steady supersonic and transonic shocks. For the dynamic stability for potential flow, we first show how the stability problem can be formulated as an initial-boundary value problem and then use the self-similarity of the problem to reduce it into a boundary value problem and further reformulate it into a free boundary problem, and we finally survey some recent developments in solving this free boundary problem for the existence of the Prandtl-Meyer configurations that tend to the steady weak supersonic or transonic oblique shock solutions as time goes to infinity. Some further developments and mathematical challenges in this direction are also discussed.

  17. Hemi-wedge osteotomy in the management of large angular deformities around the knee joint.

    Science.gov (United States)

    El-Alfy, Barakat Sayed

    2016-08-01

    Angular deformity around the knee joint is a common orthopedic problem. Many options are available for the management of such problem with varying degrees of success and failure. The aim of the present study was to assess the results of hemi-wedge osteotomy in the management of big angular deformities about the knee joint. Twenty-eight limbs in 21 patients with large angular deformities around the knee joint were treated by the hemi-wedge osteotomy technique. The ages ranged from 12 to 43 years with an average of 19.8 years. The deformity ranged from 20° to 40° with a mean of 30.39° ± 5.99°. The deformities were genu varum in 12 cases and genu valgum in 9 cases. Seven cases had bilateral deformities. Small wedge was removed from the convex side of the bone and put in the gap created in the other side after correction of the deformity. At the final follow-up, the deformity was corrected in all cases except two. Full range of knee movement was regained in all cases. The complications included superficial wound infection in two cases, overcorrection in one case, pain along the lateral aspect of the knee in one case and recurrence of the deformity in one case. No cases were complicated by nerve injury or vascular injury. Hemi-wedge osteotomy is a good method for treatment of deformities around the knee joint. It can correct large angular deformities without major complications.

  18. Solution for a system of fractional heat equations of nanofluid along a wedge

    Directory of Open Access Journals (Sweden)

    Ibrahim Rabha W.

    2015-01-01

    Full Text Available In this article, authors set a new system of fractional heat equations of nanofluid along a wedge and establish the existence and uniqueness of a solution based on the Riemann-Liouville differential operators. Sufficient conditions on the parameters of the system are imposed. A numerical solution of the system is discussed, and applications are illustrated. The technique is based on the ability of Podlubny’s matrix in Matlab to formulate the operation of fractional calculus.

  19. 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).

  20. Comparative Study between a Curved and a Wedge PEEK Cage for Single-level Anterior Cervical Discectomy and Interbody Fusion

    National Research Council Canada - National Science Library

    Kim, Hwan Soo; Song, Joon Suk; Heo, Weon; Cha, Jae Hoon; Rhee, Dong Youl

    2012-01-01

    This study evaluated the efficiency of a curved polyetheretherketone (PEEK) cage in comparison with a wedge PEEK cage according to radiologic and clinical outcomes in patients with cervical degenerative disease...

  1. Cubitus varus in adults correction with lateral closing wedge osteotomy and fixation with posterior plating

    Directory of Open Access Journals (Sweden)

    S Pandey

    2012-09-01

    Full Text Available To share the result of lateral closing wedge osteotomy and fixation with posterior reconstruction plate in correction of cubitus varus in adults. It is a retrospective case analysis of 8 cases of cubitus varus in adult treated with lateral closing wedge osteotomy through posterior triceps retracting approach. Internal fixation was done with two posterior reconstruction plates. All cases were from 15 to 29 years of age (mean 22.3 with 3 female and 5 male. All had cubitus varus ranging from 15- 28 deg (mean 20.16 deg due to childhood malunited supracondylar fracture of humerus. Indication for operation was cosmetic reason only. Follow up duration was 4-22 months (mean 12.5 months. All the osteotomy united clinically in mean duration of 9 weeks ( range 8-12 weeks with mean carrying angle 8.33 degree in postoperative phase. There was no loss of motion, no loss of fixation, no surgical site infection, nonunion or neurovascular deficit. Lateral closing wedge corrective osteotomy and fixation with posterior reconstruction plate is easy technique with satisfactory result in correction of cubitus varus in adults. Journal of College of Medical Sciences-Nepal,2012,Vol-8,No-2, 49-53 DOI: http://dx.doi.org/10.3126/jcmsn.v8i2.6839

  2. Duodenal Wedge Resection for Large Gastrointestinal Stromal Tumour Presenting with Life-Threatening Haemorrhage

    Directory of Open Access Journals (Sweden)

    Alexander Shaw

    2013-01-01

    Full Text Available Background. Duodenal gastrointestinal stromal tumours (GISTs are an uncommon malignancy of the gastrointestinal (GI tract. We present a case of life-threatening haemorrhage caused by a large ulcerating duodenal GIST arising from the third part of the duodenum managed by a limited duodenal wedge resection. Case Presentation. A 61-year-old patient presented with acute life-threatening gastrointestinal bleeding. After oesophagogastroduodenoscopy failed to demonstrate the source of bleeding, a 5 cm ulcerating exophytic mass originating from the third part of the duodenum was identified at laparotomy. A successful limited wedge resection of the tumour mass was performed. Histopathology subsequently confirmed a duodenal GIST. The patient remained well at 12-month followup with no evidence of local recurrence or metastatic spread. Conclusion. Duodenal GISTs can present with life-threatening upper GI haemorrhage. In the context of acute haemorrhage, even relatively large duodenal GISTs can be treated by limited wedge resection. This is a preferable alternative to duodenopancreatectomy with lower morbidity and mortality but comparable oncological outcome.

  3. 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.

  4. 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.

  5. The self-interaction of a fluid interface, the wavevector dependent surface tension and wedge filling

    Science.gov (United States)

    Parry, Andrew O.; Rascón, Carlos

    2011-01-01

    We argue that whenever an interface, separating bulk fluid phases, adopts a non-planar configuration (induced by a confining geometry or thermal fluctuations, say), the energy cost of it will contain a non-local self-interaction term. For systems with short-ranged forces and Ising symmetry, we determine the self-interaction by integrating out bulk-like degrees of freedom from a more microscopic Landau-Ginzburg-Wilson model. The self-interaction can be written in a simple diagrammatic form involving integrals over effective two-body forces acting at the interface and consistently accounts for a number of known features of the microscopic model, including the wavevector dependence of the surface tension describing the fluctuations of a near planar interface. When applied to wedge filling transitions, the self-interaction describes the attraction between the wetting films on either side of the wedge. We show that, for sufficiently acute wedges, this can alter the order of the filling phase transition.

  6. The self-interaction of a fluid interface, the wavevector dependent surface tension and wedge filling

    Energy Technology Data Exchange (ETDEWEB)

    Parry, Andrew O [Department of Mathematics, Imperial College London, London SW7 2BZ (United Kingdom); Rascon, Carlos [Grupo Interdisciplinar de Sistemas Complejos (GISC), Departamento de Matematicas, Universidad Carlos III de Madrid, 28911 Leganes, Madrid (Spain)

    2011-01-12

    We argue that whenever an interface, separating bulk fluid phases, adopts a non-planar configuration (induced by a confining geometry or thermal fluctuations, say), the energy cost of it will contain a non-local self-interaction term. For systems with short-ranged forces and Ising symmetry, we determine the self-interaction by integrating out bulk-like degrees of freedom from a more microscopic Landau-Ginzburg-Wilson model. The self-interaction can be written in a simple diagrammatic form involving integrals over effective two-body forces acting at the interface and consistently accounts for a number of known features of the microscopic model, including the wavevector dependence of the surface tension describing the fluctuations of a near planar interface. When applied to wedge filling transitions, the self-interaction describes the attraction between the wetting films on either side of the wedge. We show that, for sufficiently acute wedges, this can alter the order of the filling phase transition.

  7. Spatial variability of E. coli in an urban salt-wedge estuary.

    Science.gov (United States)

    Jovanovic, Dusan; Coleman, Rhys; Deletic, Ana; McCarthy, David

    2017-01-15

    This study investigated the spatial variability of a common faecal indicator organism, Escherichia coli, in an urban salt-wedge estuary in Melbourne, Australia. Data were collected through comprehensive depth profiling in the water column at four sites and included measurements of temperature, salinity, pH, dissolved oxygen, turbidity, and E. coli concentrations. Vertical variability of E. coli was closely related to the salt-wedge dynamics; in the presence of a salt-wedge, there was a significant decrease in E. coli concentrations with depth. Transverse variability was low and was most likely dwarfed by the analytical uncertainties of E. coli measurements. Longitudinal variability was also low, potentially reflecting minimal die-off, settling, and additional inputs entering along the estuary. These results were supported by a simple mixing model that predicted E. coli concentrations based on salinity measurements. Additionally, an assessment of a sentinel monitoring station suggested routine monitoring locations may produce conservative estimates of E. coli concentrations in stratified estuaries. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Partial wedge resection of nail, nail bed and nail matrix in ingrown toenail treatment

    Directory of Open Access Journals (Sweden)

    Mustafa Dönmez

    2010-05-01

    Full Text Available Objectives: Ingrown toenail is a frequent problem which can be seen in all ages. There are many treatment methods both surgical and nonsurgical. In this study we evaluated the results of wedge resection of ingrown toe nail.Patients and Methods: A total of 80 toenails of 74 patients (55 female, 19 male who complaint with discharge and deformity of their toenail underwent partial wedge resection of the nail and nail matrix. According to the Heifetz’s staging system, 34 toenails were grade II, 46 toenails were grade III. There was active drainage due to an infectious process in all effected toe nails. All patients were operated after 10 day of oral antibiotic treatment. We evaluated the recurrence, postoperative infection, patient satisfaction and time to return to work.Results: The mean follow up period was 8 months (4-12 months. There was no recurrence in any patient. Two patients came with wound drainage in postoperative 14th day. Intravenous antibiotic treatment, debridement and wound dressing with rifampicine every other day were accomplished. All patients expressed their satisfaction with surgery.Conclusion: In treatment of ingrown toenail; wedge resection of nail, nail matrix and nail bed is a very effective treatment. Recurrence rate following this technique is negligible if it is done properly and it has high patient satisfaction.

  9. Computational analysis of asymmetric water entry of wedge and ship section at constant velocity

    Science.gov (United States)

    Rahaman, Md. Mashiur; Ullah, Al Habib; Afroz, Laboni; Shabnam, Sharmin; Sarkar, M. A. Rashid

    2016-07-01

    Water impact problems receive much attention due to their short duration and large unsteady component of hydrodynamic loads. The effect of water entry has several important applications in various aspects of the naval field. Significant attention has been given to various water entry phenomena such as ship slamming, planning hulls, high-speed hydrodynamics of seaplanes, surface-piercing propellers and the interaction of high-speed liquid drops with structural elements. Asymmetric water entry may be caused by various natural phenomena such as weather conditions or strong winds. Since the determination of hydrodynamic impact load plays a vital role in designing safe and effcient vessels, an accurate and reliable prediction method is necessary to investigate asymmetric water entry problems. In this paper, water entry of a two-dimensional wedge and ship section at constant velocity in asymmetric condition will be analysed numerically and the effects of asymmetric impact on the velocity and pressure distribution will be discussed. The finite volume method is employed to solve the dynamic motion of the wedge in two-phase flow. During the water entry, the air and water interface is described implicitly by the volume of fluid (VOF) scheme. The numerical code and method was first validated for symmetric condition by one of the present author is applied for asymmetric wedge and ship section. The free surface, velocity and pressure distribution for asymmetric water entry are investigated and visualized with contour plots at different time steps.

  10. Extension of a double-wedged orogen potentially leads to the current South China Sea

    Science.gov (United States)

    Wu, G.; Lavier, L. L.

    2015-12-01

    The South China Sea (SCS) is surrounded by South China on the NW, Palawan and Reed Bank on the SE, as well as several microplates, resembling a jigsaw puzzle. In an attempt to better understand its evolution, we designed simplified thermomechanical models to simulate extension of a double-wedge-shaped orogen with highlands on both sides and lowland in the center to mimic the geological condition of the proto-SCS. We imposed constant extension rates on both sides and Gaussian-shaped thermal impulse in the center. We also varied the strength of lower crust but did not explicitly incorporate mid-ocean ridges and searfloor spreading mechanisms. We currently used symmetric double-wedge, but further tests are planed for asymmetric double-wedges. Our preliminary results show that the models produced many structures that resemble those of SCS, such as 1) a series of domino or conjugate faults sitting above a subsurface detachment (or décollement), 2) exhumed domes of middle-lower crust, 3) extreme thinning of both upper crust and lower crust, and 4) propagation of extension towards NW and SE margins. Our models suggest that superimposition of these modeled characteristics produced during several phases of extension of the SCS that may be due to thermal impulsion, magmatic events, and subduction related relaxation potentially produces high resemblance of the SCS.

  11. 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.

  12. The self-interaction of a fluid interface, the wavevector dependent surface tension and wedge filling.

    Science.gov (United States)

    Parry, Andrew O; Rascón, Carlos

    2011-01-12

    We argue that whenever an interface, separating bulk fluid phases, adopts a non-planar configuration (induced by a confining geometry or thermal fluctuations, say), the energy cost of it will contain a non-local self-interaction term. For systems with short-ranged forces and Ising symmetry, we determine the self-interaction by integrating out bulk-like degrees of freedom from a more microscopic Landau-Ginzburg-Wilson model. The self-interaction can be written in a simple diagrammatic form involving integrals over effective two-body forces acting at the interface and consistently accounts for a number of known features of the microscopic model, including the wavevector dependence of the surface tension describing the fluctuations of a near planar interface. When applied to wedge filling transitions, the self-interaction describes the attraction between the wetting films on either side of the wedge. We show that, for sufficiently acute wedges, this can alter the order of the filling phase transition.

  13. Flow Visualization around a Double Wedge Airfoil Model with Focusing Schlieren System

    Institute of Scientific and Technical Information of China (English)

    Masashi KASHITANI; Yutaka YAMAGUCHI

    2006-01-01

    In the present study, aerodynamic characteristics of the double wedge airfoil model were investigated in a transonic flow by using the shock tube as an intermittent wind tunnel. The driver and driven gases of the shock tube are dry air. The airfoil model of double wedge has the span of 58 mm, chord length c = 75 mm and its maximum thickness is 7.5 mm. The apex of the double wedge airfoil model is located on the 35% chord length from the leading edge. The range of hot gas Mach numbers are from 0.80 to 0.88, and the Reynolds numbers based on chord length are 3.11×105~3.49×105, respectively. The flow visualizations were performed by the sharp focusing schlieren method which can visualize the three dimensional flow fields. The results show that the present system can visualize the transonic flowfield clearer than the previous system, and the shock wave profiles of the center of span in the test section are visualized

  14. 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.

  15. Midterm results following medial closed wedge distal femoral osteotomy stabilized with a locking internal fixation device.

    Science.gov (United States)

    Forkel, Philipp; Achtnich, Andrea; Metzlaff, Sebastian; Zantop, Thore; Petersen, Wolf

    2015-07-01

    Aim of this study was to evaluate the subjective and radiological outcome and to evaluate the complications of a medial closing wedge osteotomy at the femur for lateral osteoarthritis with genu valgum. Twenty-three patients with grade III to IV cartilage damage and valgus knee alignment were treated with medial closing wedge osteotomy at the distal femur. The osteotomy was stabilized with an internal plate fixator. Age varied between 25 and 55 years (mean 47 years). One patient was lost to final follow-up. After 3.5 years, all Knee Osteoarthritis Outcome Score (KOOS) subitems increased significantly. There was no significant difference in the subgroup analysis of KOOS subitems for patients with and without microfracture or age (>50 vs. <50 years). There were no perioperative complications. One patient had an overcorrection. All, but one osteotomy, showed stable bone healing. There was a loss of correction due to delayed bone healing in one case. Possible explanations for this complication were injury of the lateral cortex or smoking. This case required revision with bone graft and an additional lateral plate. In no case, a conversion to an endoprosthesis was necessary. The femoral medial closing wedge osteotomy is a surgical method for improving symptoms of lateral osteoarthritis in the valgus knee. IV.

  16. 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. Panel test articles included a metallic separation bolt imbedded in the compression-pad and heat shield materials, resulting in a circular protuberance over a flat 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.

  17. Integrated waste management as a climate change stabilisation wedge for the Maltese islands.

    Science.gov (United States)

    Falzon, Clyde; Fabri, Simon G; Frysinger, Steven

    2013-01-01

    The continuous increase in anthropogenic greenhouse gas emissions occurring since the Industrial Revolution is offering significant ecological challenges to Earth. These emissions are leading to climate changes which bring about extensive damage to communities, ecosystems and resources. The analysis in this article is focussed on the waste sector within the Maltese islands, which is the largest greenhouse gas emitter in the archipelago following the energy and transportation sectors. This work shows how integrated waste management, based on a life cycle assessment methodology, acts as an effective stabilisation wedge strategy for climate change. Ten different scenarios applicable to the Maltese municipal solid waste management sector are analysed. It is shown that the scenario that is most coherent with the stabilisation wedges strategy for the Maltese islands consists of 50% landfilling, 30% mechanical biological treatment and 20% recyclable waste export for recycling. It is calculated that 16.6 Mt less CO2-e gases would be emitted over 50 years by means of this integrated waste management stabilisation wedge when compared to the business-as-usual scenario. These scientific results provide evidence in support of policy development in Malta that is implemented through legislation, economic instruments and other applicable tools.

  18. Groundwater response to tidal fluctuations in wedge-shaped confined aquifers

    Science.gov (United States)

    Cuello, Julián E.; Guarracino, Luis; Monachesi, Leonardo B.

    2017-08-01

    Most of the analytical solutions to describe tide-induced head fluctuations assume that the coastal aquifer has a constant thickness. These solutions have been applied in many practical problems ignoring possible changes in aquifer thickness, which may lead to wrong estimates of the hydraulic parameters. In this study, a new analytical solution to describe tide-induced head fluctuations in a wedge-shaped coastal aquifer is presented. The proposed model assumes that the aquifer thickness decreases with the distance from the coastline. A closed-form analytical solution is obtained by solving a boundary-value problem with both a separation of variables method and a change of variables method. The analytical solution indicates that wedging significantly enhances the amplitude of the induced heads in the aquifer. However, the effect on time lag is almost negligible, particularly near the coast. The slope factor, which quantifies the degree of heterogeneity of the aquifer, is obtained and analyzed for a number of hypothetical scenarios. The slope factor provides a simple criterion to detect a possible wedging of the coastal aquifer.

  19. Automatic lumbar vertebra segmentation from clinical CT for wedge compression fracture diagnosis

    Science.gov (United States)

    Ghosh, Subarna; Alomari, Raja'S.; Chaudhary, Vipin; Dhillon, Gurmeet

    2011-03-01

    Lumbar vertebral fractures vary greatly in types and causes and usually result from severe trauma or pathological conditions such as osteoporosis. Lumbar wedge compression fractures are amongst the most common ones where the vertebra is severely compressed forming a wedge shape and causing pain and pressure on the nerve roots and the spine. Since vertebral segmentation is the first step in any automated diagnosis task, we present a fully automated method for robustly localizing and segmenting the vertebrae for preparation of vertebral fracture diagnosis. Our segmentation method consists of five main steps towards the CAD(Computer-Aided Diagnosis) system: 1) Localization of the intervertebral discs. 2) Localization of the vertebral skeleton. 3) Segmentation of the individual vertebra. 4) Detection of the vertebrae center line and 5) Detection of the vertebrae major boundary points. Our segmentation results are promising with an average error of 1.5mm (modified Hausdorff distance metric) on 50 clinical CT cases i.e. a total of 250 lumbar vertebrae. We also present promising preliminary results for automatic wedge compression fracture diagnosis on 15 cases, 7 of which have one or more vertebral compression fracture, and obtain an accuracy of 97.33%.

  20. Open Wedge High Tibial Osteotomy and Combined Arthroscopic Surgery in Severe Medial Osteoarthritis and Varus Malalignment: Minimum 5-Year Results

    OpenAIRE

    Yoo, Moon-Jib; Shin, Yong-Eun

    2016-01-01

    Purpose To evaluate the radiologic and functional outcomes of medial open wedge high tibial osteotomy (HTO) combined with arthroscopic procedure in patients with medial osteoarthritis. Materials and Methods From June 1996 to March 2010, 26 patients (32 knees) who underwent medial open wedge osteotomy and arthroscopic operation for medial osteoarthritis were retrospectively reviewed. Measurements included hip-knee-ankle (HKA) angle, femorotibial angle, medial proximal tibial angle, posterior t...

  1. Structural basis of Smoothened regulation by its extracellular domains

    Science.gov (United States)

    Byrne, Eamon F. X.; Sircar, Ria; Miller, Paul S.; Hedger, George; Luchetti, Giovanni; Nachtergaele, Sigrid; Tully, Mark D.; Mydock-McGrane, Laurel; Covey, Douglas F.; Rambo, Robert P.; Sansom, Mark S. P.; Newstead, Simon; Rohatgi, Rajat; Siebold, Christian

    2016-07-01

    Developmental signals of the Hedgehog (Hh) and Wnt families are transduced across the membrane by Frizzled-class G-protein-coupled receptors (GPCRs) composed of both a heptahelical transmembrane domain (TMD) and an extracellular cysteine-rich domain (CRD). How the large extracellular domains of GPCRs regulate signalling by the TMD is unknown. We present crystal structures of the Hh signal transducer and oncoprotein Smoothened, a GPCR that contains two distinct ligand-binding sites: one in its TMD and one in the CRD. The CRD is stacked atop the TMD, separated by an intervening wedge-like linker domain. Structure-guided mutations show that the interface between the CRD, linker domain and TMD stabilizes the inactive state of Smoothened. Unexpectedly, we find a cholesterol molecule bound to Smoothened in the CRD binding site. Mutations predicted to prevent cholesterol binding impair the ability of Smoothened to transmit native Hh signals. Binding of a clinically used antagonist, vismodegib, to the TMD induces a conformational change that is propagated to the CRD, resulting in loss of cholesterol from the CRD-linker domain-TMD interface. Our results clarify the structural mechanism by which the activity of a GPCR is controlled by ligand-regulated interactions between its extracellular and transmembrane domains.

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

    Institute of Scientific and Technical Information of China (English)

    Zhongxian Liu; Lei Liu

    2015-01-01

    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.

  3. Great Earthquakes and Orogenic Wedge Front Processes in the Bolivian Backarc

    Science.gov (United States)

    Brooks, B. A.; Arrowsmith, R.; Echalar, A.; Yagupsky, D.; Ericksen, T. L.; Weiss, J. R.; Ahlgren, K.; Bevis, M. G.; Whipple, K. X.

    2011-12-01

    The potential for earthquakes greater than Mw 8 rupturing the decollement below Bolivia's Southern Subandes orogenic wedge has been recently recognized although great events are not documented in historical seismicity catalogs and paleoseismologic studies in this part of Bolivia are non-existent. Here, we present the first evidence for a recent surface-rupturing event of at least 7m at the range-front Mandeyapecua fault near the town of Carandaiti. SRTM topography and published industry sub-surface data demonstrate that the ~500km long fault has at least three main segments, each greater than 100 km, with total relief of 10s of meters. We acquired kinematic GPS and terrestrial laser scanner surveys at 26 sites along the 2 northern segments of the fault. Everywhere the profiles of the frontal scarp are very similar to one another: relief is ~8-12m and scarp face inclination is ~7 degrees. Moreover, the slope faces are unbroken and have constant dip, consistent with a single event rupturing each site. We estimate paleo- Mw using thrust earthquake scaling relations and an across-strike rupture length of 85-100km (the locked zone from the geodetic studies). A rupture aspect ratio of ~1:1 sets the lower limit at ~ Mw 8.0 although, if a single event is responsible, then minimum magnitude is more likely Mw ~ 8.2-8.4. Regional geomorphic studies constrain the age of the faulted lithofacies from 1.6 to 4.4ka and minimum short-term slip rates from 4.3 to 1.8 mm/yr. For comparison, published dates and seismic reflection data yield a Quaternary slip rate of 2.4mm/yr. Each of these estimates is significantly less than the geodetically-determined, currently accumulating slip rate of ~10mm/yr. The implication, then, is that some of the other structures within the wedge must be active, although, as yet, we have found no field evidence for this. We use minimum work orogenic models to investigate the physical controls on fault activity in the wedge and show that, whereas for high

  4. Alternating augite-plagioclase wedges in basement dolerites of Lockne impact structure, Sweden: A new shock wave-induced deformation feature

    Science.gov (United States)

    Agarwal, A.; Reznik, B.; Alva-Valdivia, L. M.; Srivastava, D. C.

    2017-03-01

    This paper reports peculiar alternating augite-plagioclase wedges in basement dolerites of Lockne impact structure, Sweden. The combined microscopic and spectroscopic studies of the micro/nanoscale wedges reveal that these are deformation-induced features. First, samples showing wedges, 12 out of 18 studied, are distributed in the impact structure within a radius of up to 10 km from the crater center. Second, the margins between the augite and labradorite wedges are sharp and the {110} prismatic cleavage of augite develops into fractures and thereafter into wedges. The fractures are filled with molten labradorite pushed from the neighboring bulk labradorite grain. Third, compared to the bulk labradorite, the dislocation density and the residual strain in the labradorite wedges are significantly higher. A possible mechanism of genesis of the wedges is proposed. The mechanism explains that passing of the shock waves in the basement dolerite induced (i) formation of microfractures in augite and labradorite; (ii) development of the augite prismatic cleavages into the wedges, which overprint the microfracture in the labradorite wedges; and (iii) thereafter, infilling of microfractures in the augite wedges by labradorite.

  5. Velocity asymmetry of Dzyaloshinskii domain walls in the creep and flow regimes.

    Science.gov (United States)

    Vaňatka, M; Rojas-Sánchez, J-C; Vogel, J; Bonfim, M; Belmeguenai, M; Roussigné, Y; Stashkevich, A; Thiaville, A; Pizzini, S

    2015-08-19

    We have carried out measurements of domain wall dynamics in a Pt/Co/GdOx(t) wedge sample with perpendicular magnetic anisotropy. When driven by an easy-axis field Hz in the presence of an in-plane field Hx, the domain wall propagation is different along [Formula: see text]x, as expected for samples presenting Dzyaloshinskii-Moriya (DMI) interaction. In the creep regime, the sign and the value of the domain wall velocity asymmetry changes along the wedge. We show that in our samples the domain wall speed versus Hx curves in the creep regime cannot be explained simply in terms of the variation of the domain wall energy with Hx, as suggested by previous works. For this reason the strength and the sign of the DMI cannot be extracted from these measurements. To obtain reliable information on the DMI strength using magnetic field-induced domain wall dynamics, measurements have been performed with high fields, bringing the DW close to the flow regime of propagation. In this case we find large values of the DMI, consistent in magnitude and sign with those obtained from Brillouin light scattering measurements.

  6. Comparison of Lateral Closing-Wedge Versus Medial Opening-Wedge High Tibial Osteotomy on Knee Joint Alignment and Kinematics in the ACL-Deficient Knee.

    Science.gov (United States)

    Ranawat, Anil S; Nwachukwu, Benedict U; Pearle, Andrew D; Zuiderbaan, Hendrik A; Weeks, Kenneth D; Khamaisy, Saker

    2016-12-01

    Lateral closing-wedge (LCW) and medial opening-wedge (MOW) high tibial osteotomies (HTOs) correct varus knee alignment and stabilize the anterior cruciate ligament (ACL)-deficient knee. Tibiofemoral and patellofemoral alignment and kinematics after HTO are not well quantified. To compare the effect of LCW and MOW HTO on tibiofemoral and patellofemoral alignment in the ACL-deficient knee. Controlled laboratory study. Anterior drawer, Lachman, and pivot-shift tests were performed on cadaveric specimens (N = 16), and anterior tibial translation and tibial rotation were measured for the native and ACL-sectioned knee. The right and left knee of each cadaveric specimen underwent an LCW and MOW HTO, respectively, and stability testing was repeated. All cadavers underwent pre- and postosteotomy computerized tomography with 3-dimensional computer modeling to determine the effect of HTO on posterior tibial slope, as well as tibial and patellofemoral axial plane alignment (tibial axial rotation and patellar axial tilt). Correction to neutral coronal alignment was obtained with both osteotomy techniques; however, larger posterior tibial slope neutralization was achieved with LCW compared with MOW (mean ± SD, 11° ± 3.8° vs 5° ± 5°). LCW demonstrated a greater decrease in anterior tibial translation (P rotation with pivot shift. Relative to MOW, LCW resulted in greater tibial axial rotation and patellar axial tilt (7.7° ± 4° and 5.6° ± 3.9° [LCW], 2.8° ± 2.3° and 2.4° ± 0.9° [MOW], respectively; P rotation and lateral patellar tilt, which may adversely affect the patellofemoral joint. More work is needed to understand the clinical and functional outcome of these biomechanical findings in the ACL-deficient knee. © 2016 The Author(s).

  7. 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.

  8. Control of structural inheritance on thrust initiation and material transfer in accretionary wedges

    Science.gov (United States)

    Leever, Karen; Geersen, Jacob; Ritter, Malte; Lieser, Kathrin; Behrmann, Jan

    2016-04-01

    Faults in the incoming sediment layer are commonly observed in subduction zone settings and well developed in the incoming plate off Sumatra. To investigate how they affect the structural development of the accretionary wedge, we conducted a series of 2D analogue tectonic experiments in which a 2 cm thick quartz sand layer on top of a thin detachment layer of glass beads was pulled against a rigid backstop by a basal conveyor belt in a 20cm wide box with glass walls. A gap at the base of the back wall avoids entrainment of the glass beads. At regular spacing of either 2.3, 5.5 or 7.8 cm (fractions of the thrust sheet length in the reference model), conjugate pairs of weakness zones dipping 60deg were created by cutting the sand layer with a thin (1 mm) metal blade. Both the undisturbed sand and the pre-cuts have an angle of internal friction of ~29o, but their cohesion is different by 50 Pa (110 Pa for the undisturbed material, 60 Pa along the pre-cuts). Friction of the glass beads is ~24deg. The experiments are monitored with high resolution digital cameras; displacement fields derived from digital image correlation are used to constrain fault activity. In all experiments, a critically tapered wedge developed with a surface slope of 7.5deg. In the reference model (no weakness zones in the input section), the position of new thrust faults is controlled by the frontal slope break. The average length of the thrust sheets is 11 cm and the individual thrusts accommodate on average 8 cm displacement each. The presence of weakness zones causes thrust initiation at a position different from the reference case, and affects their dip. For a fault spacing of 7.8 cm (or 75% of the reference thrust sheet length), every single incoming weakness zone causes the formation of a new thrust, thus resulting in thrust sheets shorter than the equilibrium case. In addition, less displacement is accommodated on each thrust. As a consequence, the frontal taper is smaller than expected

  9. Observations of the Columbia River salt wedge and estuarine turbidity maximum using AUVs

    Science.gov (United States)

    McNeil, C. L.; Shcherbina, A.; Litchendorf, T.; Sanford, T. B.; Martin, D.; Baptista, A. M.; Lopez, J.; Crump, B.

    2012-12-01

    We present detailed observations of the salt wedge and estuarine turbidity maxima (ETM) in the North Channel of the Columbia River estuary (OR, USA) under conditions of high river discharge during May 2012. Measurements were made using two REMUS-100 autonomous underwater vehicles (AUVs; Hydroid, Inc.) equipped with SBE-49 CTDs (Seabird-Electronics, Inc.) for water temperature and salinity, upward/downward looking ADCPs (Teledyne RDI, Inc.) for currents, and ECO Puck triplets (WET Labs, Inc.) for optical backscatter measurement of turbidity. The acoustic backscatter intensity from the ADCP was also used as a proxy measurement for suspended sediments and was found to correlate quite well with the optical backscatter measurements. Daily forecasts of tidal currents in the estuary were used to simulate the AUV path in advance of deployment to aid data collection. Repeat AUV sections were made along and across the channel during flood tide. The turbidity and height above riverbed of the bottom boundary layer was observed to increase toward the deeper waters at the center of the channel. An ETM-like feature was observed ahead of the advancing salt wedge front with locally higher turbidity levels, presumably the result of flocculation and resuspension. To visualize better the repeat section measurements we made data movies. Each frame of the movie is our best estimate of a synoptic snapshot of along-section tracer distribution at a given point in time. These snapshots were created by re-location of non-synoptic AUV measurements to account for the advection of water parcels. An example data movie showing the intrusion of the salt wedge during the flood tide will be presented.

  10. Earthquake occurrence processes in the Indo-Burmese wedge and Sagaing fault region

    Science.gov (United States)

    Kundu, Bhaskar; Gahalaut, V. K.

    2012-02-01

    Earthquakes in the Indo-Burmese wedge and Sagaing fault regions occur in response to the partitioning of the India-Sunda motion along these two distinct boundaries. Under the accretionary wedge of the Indo-Burmese arc, majority of the earthquakes occur in the depth range of 30-60 km and define an eastward gently dipping seismicity trend surface that coincides with the Indian slab. The dip of the slab steepens in the east direction and earthquakes occur down to a depth of 150 km, though the slab can be traced up to the 660 km discontinuity. Although these features are similar to a subduction zone, the nature of the earthquakes and our analysis of their focal mechanisms suggest that these earthquakes are of intra-slab type which occur on steep plane within the Indian plate and the sense of motion implies a northward relative motion with respect to the Sunda plate. Thus these earthquakes and the stress state do not support active subduction across the Indo-Burmese arc which is also consistent with the relative motion of India-Sunda plates. The absence of inter-plate earthquakes, lack of evidence of the occurrence of great earthquakes in the historical records and non-seismogenic nature of the plate interface under the accretionary wedge suggest that seismic hazard due to earthquakes along the plate boundary may be relatively low. However, major intra-slab earthquakes at shallow and intermediate depths may still cause damage in the sediment filled valley regions of Manipur and Cachar in India and Chittagong and Sylhet regions of Bangladesh. In the Sagaing fault region, earthquakes occur through dextral strike slip motion along the north-south oriented plane and the stress state is consistent with the plate motion across the Sagaing fault.

  11. Numerical modeling of mantle wedge processes and exhumation of UHP mantle in subduction zones

    Science.gov (United States)

    Gorczyk, W.; Gerya, T. V.; Guillot, S.; Connolly, J. A.; Yuen, D.

    2007-12-01

    The upwelling of subduction generated partially molten rocks is potentially a mechanism for the exhumation of UHP rocks through the mantle wedge. We investigated this processes using a 2-D coupled petrological- thermomechanical model that incorporates slab dehydration and water transport as well as partial melting of mantle and crustal rocks. This approach allows us to study the dynamics of mantle wedge processes including evolution of partially molten plumes and their interaction with surrounding dry mantle. To study the internal structure of the plumes we used ultra-high resolution numerical simulations with 10 billion active markers to detail the internal structure of natural plumes originating from the slab. The plumes consist of partially molten hydrated peridotite, dry solid mantle and subducted oceanic crust, which may comprise up to 12 volume % of the plume. As the plumes grow and mature these materials mix chaotically resulting in attenuation and duplication of the original layering on scales of 1-1000 m. Comparison of numerical results with geological observations from the Horoman ultramafic complex in Japan suggests that mixing and differentiation processes related to development of partially molten plumes above slabs may be responsible for strongly layered lithologically mixed (marble cake) structure of asthenospheric mantle wedges. The recent discovery of garnet bearing peridotites in the subduction zone of the Great Antilles in Hispaniola has raised questions about the process that leads to their exhumation. To evaluate whether upwelling plumes are a plausible exhumation mechanism we investigated the dynamics of subduction of slow spreading ridges. The results show that subduction of strongly serpentinized oceanic plate causes strong dehydration of the slab and leads to a rheological weakening of the interface between subducting and overriding plate. This weakening triggers trench retreat and massive asthenospheric upwelling into the gap between the

  12. PROPERTIES OF NATURAL CAVITATION FLOWS AROUND A 2-D WEDGE IN SHALLOW WATER

    Institute of Scientific and Technical Information of China (English)

    CHEN Xin; LU Chuan-jing; LI Jie; CHEN Ying

    2011-01-01

    When a body navigates with cavity in shallow water,both flexible free surface and rigid bottom wall will produce great influences on the cavity shape and hydrodynamic performances,and further affect the motion attitude and stability of the body.In the present work,characteristics of the natural cavitating flow around a 2-D symmetrical wedge in shallow water were investigated and the influences of two type boundaries on the flow pattern were analyzed.The Volume Of Fluid (VOF) multiphaseflow method which is suitable for free surface problems was utilized,coupled with a natural cavitation model to deal with the mass-transfer process between liquid and vapor phases.Within the range of the cavitation number for computation (0.07-1.81),the cavity configurations would be divided into three types,viz.,stable type,transition type and wake-vortex type.In this article,the shapes of the free surface and the cavity surface,and the hydrodynamic performance of the wedge were discussed under the conditions of relatively small cavitation number ( < 0.256 ).The present numerical cavity lengths generally accord with experimental data.When the cavitation number was decreased,the cavity was found to become longer and thicker,and the scope of the deformation of the free surface also gradually extends.The free surface and the upper cavity surface correspond fairly to their shapes.However,the lower side of the cavity surface was rather leveled due to the influence of wall boundary.The lift and drag coefficients of this 2-D wedge basically keep linear relations with the natural cavitation number smaller than 0.157,whereas direct proportion for drag and inverse proportion for lift.

  13. 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.

  14. 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.

  15. 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...... effect between a transverse magnetic (or transverse electric) incident plane wave and the transverse electric (or transverse magnetic) slope-diffracted field. The coupling effect is not described by the existing GTD slope diffraction coefficient...

  16. Polarization sensitive localization based super-resolution microscopy with a birefringent wedge

    Science.gov (United States)

    Sinkó, József; Gajdos, Tamás; Czvik, Elvira; Szabó, Gábor; Erdélyi, Miklós

    2017-03-01

    A practical method has been presented for polarization sensitive localization based super-resolution microscopy using a birefringent dual wedge. The measurement of the polarization degree at the single molecule level can reveal the chemical and physical properties of the local environment of the fluorescent dye molecule and can hence provide information about the sub-diffraction sized structure of biological samples. Polarization sensitive STORM imaging of the F-Actins proved correlation between the orientation of fluorescent dipoles and the axis of the fibril.

  17. A possible relict mantle wedge:Geochemical evidence from Paleogene volcanics in North China

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The major and trace element and isotopic composition were analyzed for the Paleogene volcanics in North China dated by the K-Ar method. The geochemical data show that most volcanics are in caic-alkaline series and the minor is in alkaline series. They differ obviously from Neogene and Quaternary volcanics in geochemistry. In particular, the Paleogene volcanics from the southern part of North China were derived from enriched lithospheric mantle (EMⅡ), which were likely to be a relict mantle wedge formed during the subduction of the Yangtze plate into the North China plate in late Triassic (Indo- Sinian).

  18. Design, performance, and calibration of CMS hadron-barrel calorimeter wedges

    Energy Technology Data Exchange (ETDEWEB)

    Abdullin, S. [Fermi National Accelerator Lab., Batavia, IL (United States)]|[Univ. of Maryland, College Park, MD (United States); Abramov, V.; Goncharov, P.; Khmelnikov, A.; Korablev, A.; Korneev, Y.; Krinitsyn, A.; Kryshkin, V.; Lukanin, V.; Pikalov, V.; Ryazanov, A.; Talov, V.; Turchanovich, L.; Volkov, A. [IHEP, Protvino (Russian Federation); Acharya, B.; Banerjee, S.; Banerjee, S.; Chendvankar, S.; Dugad, S.; Kalmani, S.; Katta, S.; Mazumdar, K.; Mondal, N.; Nagaraj, P.; Patil, M.; Reddy, L.; Satyanarayana, B.; Sudhakar, K.; Verma, P. [Tata Inst. of Fundamental Research, Mumbai (India); Adams, M.; Burchesky, K.; Qian, W. [Univ. of Illinois at Chicago, Chicago, IL (United States); Akchurin, N.; Carrell, K.; Guemues, K.; Thomas, R. [Texas Tech Univ., Dept. of Physics, Lubbock, TX (United States); Akgun, U.; Ayan, S.; Duru, F.; Merlo, J.P.; Mestvirishvili, A.; Miller, M.; Norbeck, E.; Olson, J.; Onel, Y.; Schmidt, I. [Univ. of Iowa, Iowa City, IA (United States); Anderson, E.W.; Hauptman, J. [Iowa State Univ., Ames, IA (United States); Antchev, G.; Hazen, E.; Lawlor, C.; Machado, E.; Posch, C.; Rohlf, J.; Wu, S.X. [Boston Univ., Boston, MA (United States); Aydin, S.; Dumanoglu, I.; Eskut, E.; Kayis-Topaksu, A.; Polatoz, A.; Onengut, G.; Ozdes-Koca, N. [Cukurova Univ., Adana (Turkey); Baarmand, M.; Ralich, R.; Vodopiyanov, I. [Florida Inst. of Technology, Melbourne, FL (United States); Baden, D.; Bard, R.; Eno, S.; Grassi, T.; Jarvis, C.; Kellogg, R.; Kunori, S.; Skuja, A. [Univ. of Maryland, College Park, MD (United States); Barnes, V.; Laasanen, A.; Pompos, A. [Purdue Univ., West Lafayette, IN (United States); Bawa, H.; Beri, S.; Bhatnagar, V.; Kaur, M.; Kohli, J.; Kumar, A.; Singh, J. [Panjab Univ., Chandigarh (India); Baiatian, G.; Sirunyan, A. [Yerevan Physics Inst., Yerevan (Armenia); Bencze, G.; Vesztergombi, G.; Zalan, P. [KFKI-RMKI, Research Inst. for Particle and Nuclear Physics, Budapest (Hungary)] [and others

    2008-05-15

    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. 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. The energy dependent time slewing effect was measured and tuned for optimal performance. (orig.)

  19. Modified closing-opening wedge osteotomy for the treatment of sagittal malalignment in thoracolumbar fractures malunion.

    Science.gov (United States)

    Bourghli, Anouar; Boissière, Louis; Vital, Jean-Marc; Bourghli, Mohamed Aiman; Almusrea, Khaled; Khoury, Ghassan; Obeid, Ibrahim

    2015-12-01

    Many techniques have been described for the surgical treatment of rigid posttraumatic thoracolumbar kyphosis, but none is well adapted to the modified shape of the wedged vertebra. The study aimed to describe the modified closing-opening wedge osteotomy (MCOWO), a new osteotomy technique that adapts to the triangular shape of the wedged apical vertebra of the deformity. A retrospective assessment of the degree of correction before and after the MCOWO was carried out. Ten patients presenting rigid posttraumatic thoracolumbar kyphosis were enrolled in this study. We used preoperative and postoperative whole spine radiographs to assess the sagittal plane parameters, and computed tomography scan for measurement of the vertebral segment height at the osteotomy level, spinal cord length, aorta length, and fusion rate. Ten patients underwent the MCOWO at T12 or L1. The procedure involves removing the postero-superior triangular corner of the wedged vertebra and transforming it to a shape similar to a trapezoid. The patients' mean age was 36.6±7.5 years, the mean time between the fracture and the surgery was 12.2±5.6 months, and the mean follow-up was 30.6±5 months. In all patients, statistically significant improvement was observed in the sagittal plane after surgery. The thoracolumbar angle improved from 52±6° preoperatively to 7.1±5.7° at the last follow-up. Mean osteotomy angle was 38.1±2.6°, mean spinal cord shortening was 1.2±0.2 cm, and mean aorta lengthening was 2.3±0.4 cm. All the patients showed complete fusion at 2 years, and none required revision surgery. Two patients presented a temporary unilateral weakness that recovered completely within 3 months after the surgery. The MCOWO is an interesting procedure for patients with posttraumatic thoracolumbar kyphosis. The modified osteotomy is adapted to the modified shape of the compressed vertebra. Spinal cord shortening and aorta lengthening were well tolerated in all patients. Copyright © 2015

  20. External post-tensioning of cfrp tendons using integrated sleeve-wedge anchorage

    DEFF Research Database (Denmark)

    Schmidt, Jacob Wittrup; Bennitz, Anders; Goltermann, Per

    2012-01-01

    Strengthening of structures using external post-tension CFRP systems have proven to be anefficient method as such system increases the structural capacity and reduces cracks and deflection. Sufficient anchorage is of significant importance since the anchorage provides the connection between...... the post-tensioning system and the remaining structure. A special designed integrated sleeve-wedge anchorage has therefore been designed to improve the reliability of the mounting procedure, reduce the possible modes of failure and thus provide desired anchorage. The present research shows that adequate...

  1. 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

    coupling angle, and transducer actuation method (single-frequency actuation or frequency-modulation actuation). The energy-density analysis is based on measuring the transmitted light intensity through a microfluidic channel filled with a suspension of 5-μm-diameter beads and the results with the tunable...... particle patterns with average acoustic energy densities comparable to those obtained using single-frequency actuation.......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...

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

    DEFF Research Database (Denmark)

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

    2013-01-01

    coupling angle, and transducer actuation method (single-frequency actuation or frequency-modulation actuation). The energy-density analysis is based on measuring the transmitted light intensity through a microfluidic channel filled with a suspension of 5 µm diameter beads and the results with the tunable...... uniform particle patterns with average acoustic energy densities comparable to those obtained using single-frequency actuation.......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 transducer geometry, transducer...

  3. Solution of the Falkner Skan equation for wedge by Adomian Decomposition Method

    Science.gov (United States)

    Alizadeh, Ebrahim; Farhadi, Mousa; Sedighi, Kurosh; Ebrahimi-Kebria, H. R.; Ghafourian, Akbar

    2009-03-01

    The Adomian Decomposition Method is employed in the solution of the two dimensional laminar boundary layer of Falkner-Skan equation for wedge. This work aims at the solution of momentum equation in the case of accelerated flow and decelerated flow with separation. The Adomian Decomposition Method is provided an analytical solution in the form of an infinite power series. The effect of Adomian polynomials terms is considered on accuracy of the results. The velocity profiles in boundary layer are obtained. Results show a good accuracy compared to the exact solution.

  4. Researches on the distribution law of vector sound field in elastic wedge bottom

    Institute of Scientific and Technical Information of China (English)

    ZHANG Haigang; PIAO Shengchun; YANG Shi'e; AN Xudong

    2011-01-01

    The method based on elastic parabolic equation method for calculating the sound vector field has been studied. The vector field in water and corresponding seismic wave field had been calculated for infra-sound in oceanic environment with elastic wedge bottom. The effects on sound field distribution for different frequency and depth of sound source had been researched, result shows that there is sound energy leakage into the bottom, the position where leakage occurred can be determined by the ratio of the ocean depth to the wavelength, as compared with normal mode theory.

  5. On the Accuracy of Asymptotic Solutions for TM Waves Diffracting on an Impedance Wedge

    Directory of Open Access Journals (Sweden)

    Sonia Fu

    2014-01-01

    Full Text Available The contribution focuses on the accuracy of two asymptotic solutions aimed at representing the electromagnetic field scattered by penetrable wedges. One is a heuristic manipulation of the solution for the perfect electrical conductor, and the other one is a more rigorous coefficient based on approximate boundary conditions. The results presented here extend those proposed by other authors by illustrating the accuracy of such solutions at the edge of validity of the uniform theory of diffraction. In particular, they show that the heuristic formulation can be freely applied in similar conditions, while the other might not always lead to accurate predictions.

  6. CHIRP seismic reflection study of falling-stage (forced regressive) sediment wedges on the New Jersey outer continental shelf

    Science.gov (United States)

    Santra, M.; Goff, J.; Ron, S.; Austin, J.

    2007-12-01

    High-resolution (1-12 kHz), deep-towed and hull-mounted CHIRP seismic data were collected on the New Jersey outer shelf in 2001, 2002 and 2006 as part of Office of Naval Research-funded projects. These data have imaged two well-developed, offlapping sedimentary wedges (named outer-shelf wedge and deep-shelf wedge) that are now postulated to have developed on the falling-stage limb of the last glacial cycle, during some time prior to the Last Glacial Maximum (20-22 kyrs BP). These wedges formed atop the high-amplitude, regional R horizon, a complex erosional unconformity that formed about 40,000 years ago. The outer shelf wedge is also characterized in part by an enigmatic, erose boundary separating layered horizons below from a mostly transparent section above. New Jersey shelf wedges appear analogous to forced-regressive units imaged on the Rhone shelf edge, as well as Eocene sections documented from seismic-scale outcrops on Spitsbergen Island. These examples can reach thicknesses up to 100 m on the shelf edge and uppermost slope, but usually thin rapidly downslope. Such wedges represent one of two documented mechanisms involving sand transport across a shelf margin into deeper water settings, the other being a canyonized shelf-edge. Our study will includes analysis of the CHIRP data and, if available, additional ground truth provided by short cores collected in summer 2007 at numerous intra-wedge stratigraphic horizons. Our goals are to understand the external and internal geometry of the wedges and sediment pathways across the paleo-shelf. These data should allow us to characterize margin segments that build during sea-level fall by slope-apron accretion rather than by the formation of channel-levee complexes. The literature is heavily weighted by the latter and their associated canyon systems, but information on shelf-edge attached slope aprons and how they contribute to deep-water sedimentation, and in particular the delivery of clean sands to slope settings

  7. 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

    2017-08-01

    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

  8. 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.

  9. Study on effect of segments erection tolerance and wedge-shaped segment on segment ring in shield tunnel

    Institute of Scientific and Technical Information of China (English)

    CHEN Jun-sheng; MO Hai-hong

    2006-01-01

    Deformation and dislocations of segments of shield tunnel in construction stage have apparent effect on tunnel structure stress and even cause local cracks and breakage in tunnel. 3D finite element method was used to analyze two segment ring models under uniform injected pressure: (1) segment ring without wedge-shaped segment, which has 16 types of preinstall erection tolerance; (2) segment ring with wedge-shaped segment, which has no preinstall erection tolerance. The analysis results indicate that different erection tolerances can cause irregular deformation in segment ring under uniform injected pressure, and that the tolerance values are enlarged further. Wedge-shaped segment apparently affects the overall deformation of segment ring without erection tolerances. The uniform injected pressure can cause deformation of ring with wedge-shaped segment irregular,and dislocations also appear in this situation. The stress of segment with erection tolerances is much larger than that of segment without erection tolerances. Enlarging the central angle of wedge-shaped segment can make the irregular deformation and dislocations of segments smaller. The analysis results also provide basis for erection tolerance control and improvement of segment constitution.

  10. Comparative Study between a Curved and a Wedge PEEK Cage for Single-level Anterior Cervical Discectomy and Interbody Fusion.

    Science.gov (United States)

    Kim, Hwan Soo; Song, Joon Suk; Heo, Weon; Cha, Jae Hoon; Rhee, Dong Youl

    2012-09-01

    This study evaluated the efficiency of a curved polyetheretherketone (PEEK) cage in comparison with a wedge PEEK cage according to radiologic and clinical outcomes in patients with cervical degenerative disease. A total of 37 patients who suffering from cervical disc disease with radiculopathy or myelopathy were reviewed retrospectively. Seventeen patients were underwent anterior cervical discectomy and interbody fusion with a curved shape PEEK cage (curved cage group), and twenty patients with wedge shape PEEK cage (wedge cage group). Clinical assessment was graded using Odom's criteria, NDI score and VAS score. For radiologic analysis, disc height (DH), segmental angle (SA), subsidence were measured at the preoperative and last follow up. A comparison of the preoperative and postoperative results revealed improvements after the surgery in the DH and SA in both cage groups. The change of postoperative DH between the preoperative and the last follow-up in wedge cage group and curved cage group was 6.85% and 25.5%, respectively. The change of postoperative SA was 1.75° and 0.95°, respectively. There was no statistically significant difference in the DH and SA between the 2 groups. The subsidence rate in the wedge cage group and curved cage group was 20% and 6%, respectively. The 2 different cage groups showed significant improvements in the disc height, segmental angle and clinical outcomes. However, the shape of PEEK Cage influences the tendency for subsidence. Increasing contact surface area and fitting into two adjacent vertebral body prevent significant subsidence.

  11. Changes in basal dip and frictional properties controlling orogenic wedge propagation and frontal collapse: the External central Betics case

    Science.gov (United States)

    Jiménez-Bonilla, Alejandro; Torvela, Taija; Balanyá, Juan-Carlos; Díaz-Azpiroz, Manuel; Expósito, Inmaculada

    2016-04-01

    Orogenic wedges and their key component, thin-skinned fold-and-thrust belts (FTBs), have been extensively studied through both field examples and modelling. The overall dynamics of FTBs are, therefore, well understood. One of the less understood aspects is: what is the combined influence of across-strike changes in the detachment properties and the basement topography on the behaviour of an orogenic wedge, as the deformation progresses towards the foreland? In this study, we use field data combined with reflection seismic interpretation and well data from the External Zones of the Central Betics FTB, S Spain, to identify a basement "threshold" coinciding with a thinning out of a weak substrate (Triassic evaporites) in the wedge basal detachment. The basal changes influenced the tempo-spatial (4D) local wedge dynamics at ~Early Langhian times, leading to stagnation of FTB propagation, topographic build-up and subsequent collapse of the FTB front, which was enhanced by arc-parallel stretching. This development led to a formation of an important depocentre filled with a thick Langhian mélange unit and later sediments deposited in the NW-migrating foreland basin. This case study illustrates the importance of across-strike changes in wedge basal properties to the stability of the FTB front, especially in terms of the collapse/extensional structures.

  12. Protein domain prediction

    NARCIS (Netherlands)

    Ingolfsson, Helgi; Yona, Golan

    2008-01-01

    Domains are considered to be the building blocks of protein structures. A protein can contain a single domain or multiple domains, each one typically associated with a specific function. The combination of domains determines the function of the protein, its subcellular localization and the interacti

  13. Membrane binding domains

    OpenAIRE

    Hurley, James H.

    2006-01-01

    Eukaryotic signaling and trafficking proteins are rich in modular domains that bind cell membranes. These binding events are tightly regulated in space and time. The structural, biochemical, and biophysical mechanisms for targeting have been worked out for many families of membrane binding domains. This review takes a comparative view of seven major classes of membrane binding domains, the C1, C2, PH, FYVE, PX, ENTH, and BAR domains. These domains use a combination of specific headgroup inter...

  14. 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.

  15. Simulation of arrested salt wedges with a multi-layer Shallow Water Lattice Boltzmann model

    Science.gov (United States)

    Prestininzi, P.; Montessori, A.; La Rocca, M.; Sciortino, G.

    2016-10-01

    The ability to accurately and efficiently model the intrusion of salt wedges into river beds is crucial to assay its interaction with human activities and the natural environment. We present a 2D multi-layer Shallow Water Lattice Boltzmann (SWLB) model able to predict the salt wedge intrusion in river estuaries. The formulation usually employed for the simulation of gravity currents is here equipped with proper boundary conditions to handle both the downstream seaside outlet and the upstream river inlet. Firstly, the model is validated against highly accurate semi-analytical solutions of the steady state 1D two-layer Shallow Water model. Secondly, the model is applied to a more complex, fully 3D geometry, to assess its capability to handle realistic cases. The simple formulation proposed for the shear interlayer stress is proven to be consistent with the general 3D viscous solution. In addition to the accuracy, the model inherits the efficiency of the Lattice Boltzmann approach to fluid dynamics problems.

  16. Composite wedge failure using photogrammetric measurements and DFN-DEM modelling

    Directory of Open Access Journals (Sweden)

    Viviana Bonilla-Sierra

    2017-02-01

    Full Text Available Analysis and prediction of structural instabilities in open pit mines are an important design and operational consideration for ensuring safety and productivity of the operation. Unstable wedges and blocks occurring at the surface of the pit walls may be identified through three-dimensional (3D image analysis combined with the discrete fracture network (DFN approach. Kinematic analysis based on polyhedral modelling can be used for first pass analysis but cannot capture composite failure mechanisms involving both structurally controlled and rock mass progressive failures. A methodology is proposed in this paper to overcome such limitations by coupling DFN models with geomechanical simulations based on the discrete element method (DEM. Further, high resolution photogrammetric data are used to identify valid model scenarios. An identified wedge failure that occurred in an Australian coal mine is used to validate the methodology. In this particular case, the failure surface was induced as a result of the rock mass progressive failure that developed from the toe of the structure inside the intact rock matrix. Analysis has been undertaken to determine in what scenarios the measured and predicted failure surfaces can be used to calibrate strength parameters in the model.

  17. 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.

  18. Compact multi-projection 3D display using a wedge prism

    Science.gov (United States)

    Park, Soon-gi; Lee, Chang-Kun; Lee, Byoungho

    2015-03-01

    We propose a compact multi-projection system based on integral floating method with waveguide projection. Waveguide projection can reduce the projection distance by multiple folding of optical path inside the waveguide. The proposed system is composed of a wedge prism, which is used as a waveguide, multiple projection-units, and an anisotropic screen made of floating lens combined with a vertical diffuser. As the projected image propagates through the wedge prism, it is reflected at the surfaces of prism by total internal reflections, and the final view image is created by the floating lens at the viewpoints. The position of view point is decided by the lens equation, and the interval of view point is calculated by the magnification of collimating lens and interval of projection-units. We believe that the proposed method can be useful for implementing a large-scale autostereoscopic 3D system with high quality of 3D images using projection optics. In addition, the reduced volume of the system will alleviate the restriction of installment condition, and will widen the applications of a multi-projection 3D display.

  19. 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.

  20. 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.

  1. Enhanced performance of fast-response 3-hole wedge probes for transonic flows in axial turbomachinery

    Energy Technology Data Exchange (ETDEWEB)

    Delhaye, D.; Paniagua, G. [von Karman Institute for Fluid Dynamics, Turbomachinery and Propulsion Department, Rhode-Saint-Genese (Belgium); Fernandez Oro, J.M. [Universidad de Oviedo, Area de Mecanica de Fluidos, Gijon (Spain); Denos, R. [European Commission, Directorate General for Research, Brussels (Belgium)

    2011-01-15

    The paper presents the development and application of a three-sensor wedge probe to measure unsteady aerodynamics in a transonic turbine. CFD has been used to perform a detailed uncertainty analysis related to probe-induced perturbations, in particular the separation zones appearing on the wedge apex. The effects of the Reynolds and Mach numbers are studied using both experimental data together with CFD simulations. The angular range of the probe and linearity of the calibration maps are enhanced with a novel zonal calibration technique, used for the first time in compressible flows. The data reduction methodology is explained and demonstrated with measurements performed in a single-stage high-pressure turbine mounted in the compression tube facility of the von Karman Institute. The turbine was operated at subsonic and transonic pressure ratios (2.4 and 5.1) for a Reynolds number of 10{sup 6}, representative of modern engine conditions. Complete maps of the unsteady flow angle and rotor outlet Mach number are documented. These data allow the study of secondary flows and rotor trailing edge shocks. (orig.)

  2. Measurement of tibial slope angle after medial opening wedge high tibial osteotomy: case series

    Directory of Open Access Journals (Sweden)

    Ricardo Hideki Yanasse

    Full Text Available CONTEXT AND OBJECTIVE: In the past, changes in tibial slope were not considered when planning or evaluating osteotomies, and success in high tibial osteotomy was related to the alignment and amount of femorotibial angular correction. The aim here was to measure changes in tibial slope after medial opening wedge tibial osteotomy and investigate the effect of tibial slope angle on the clinical results. DESIGN AND SETTING: Retrospective review study on a series of cases, at the Department of Orthopedics and Traumatology, Faculdade de Medicina de Marília (Famema, Marília, Brazil. METHODS: Twenty-eight patients were studied, and a total of thirty-one knees. Lateral roentgenograms of the tibia were used pre and postoperatively to measure the tibial slope based on the proximal tibial anatomical axis. The clinical results were measured using the Lysholm knee score. RESULTS: There was an average increase in tibial slope angle after surgery of 2.38° (95% confidence interval: ± 0.73°. There was no correlation (r = -0.28 between the postoperative Lysholm knee score and the difference in tibial slope angle from before to after surgery (P = 0.13. CONCLUSION: Medial opening wedge tibial osteotomy led to a small increase in tibial slope. No significant correlation was found between increased tibial slope and short-term clinical results after high tibial osteotomy. Other clinical studies are needed in order to establish whether extension or flexion osteotomy could benefit patients with medial compartment gonarthrosis.

  3. 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.

  4. Analytical correction of an extension of the "MU Fraction Approximation" for Varian enhanced dynamic wedges.

    Science.gov (United States)

    Gossman, Michael S; Sharma, Subhash C

    2010-04-01

    The most common method to determine enhanced dynamic wedge factors begins with the use of segmented treatment tables. These segmental dose delivery values set as a function of upper jaw position are the backbone of a calculation process coined the "MU Fraction Approximation." Analytical and theoretical attempts have been made to extend and alter the mathematics for this approximation for greater accuracy. A set of linear equations in the form of a matrix are introduced here which correct one published extension of the MU Fraction Approximation as it applies to both symmetric and asymmetric photon fields. The matrix results are compared to data collected from a commissioned Varian Eclipse Treatment Planning System and previously published research for Varian linear accelerators. A total enhanced dynamic wedge factor with excellent accuracy was achieved in comparison to the most accurate previous research found. The deviation seen here is only 0.4% and 1.0% for symmetric and asymmetric fields respectively, for both 6MV and 18MV photon beams.

  5. Enhanced performance of fast-response 3-hole wedge probes for transonic flows in axial turbomachinery

    Science.gov (United States)

    Delhaye, D.; Paniagua, G.; Fernández Oro, J. M.; Dénos, R.

    2011-01-01

    The paper presents the development and application of a three-sensor wedge probe to measure unsteady aerodynamics in a transonic turbine. CFD has been used to perform a detailed uncertainty analysis related to probe-induced perturbations, in particular the separation zones appearing on the wedge apex. The effects of the Reynolds and Mach numbers are studied using both experimental data together with CFD simulations. The angular range of the probe and linearity of the calibration maps are enhanced with a novel zonal calibration technique, used for the first time in compressible flows. The data reduction methodology is explained and demonstrated with measurements performed in a single-stage high-pressure turbine mounted in the compression tube facility of the von Karman Institute. The turbine was operated at subsonic and transonic pressure ratios (2.4 and 5.1) for a Reynolds number of 106, representative of modern engine conditions. Complete maps of the unsteady flow angle and rotor outlet Mach number are documented. These data allow the study of secondary flows and rotor trailing edge shocks.

  6. Quantitative Verification of Dynamic Wedge Dose Distribution Using a 2D Ionization Chamber Array.

    Science.gov (United States)

    Sahnoun, Tarek; Farhat, Leila; Mtibaa, Anis; Besbes, Mounir; Daoud, Jamel

    2015-10-01

    The accuracy of two calculation algorithms of the Eclipse 8.9 treatment planning system (TPS)--the anisotropic analytic algorithm (AAA) and pencil-beam convolution (PBC)--in modeling the enhanced dynamic wedge (EDW) was investigated. Measurements were carried out for 6 and 18 MV photon beams using a 2D ionization chamber array. Accuracy of the TPS was evaluated using a gamma index analysis with the following acceptance criteria for dose differences (DD) and distance to agreement (DTA): 3%/3 mm and 2%/2 mm. The TPS models the dose distribution accurately except for 20×20 cm(2) field size, 60 (°) and 45 (°) wedge angles using PBC at 6 MV photon energy. For these latter fields, the pass rate and the mean value of gamma were less than 90% and more than 0.5, respectively at the (3%/3 mm) acceptance criteria. In addition, an accuracy level of (2%/2 mm) was achieved using AAA with better agreement for 18 MV photon energy.

  7. Template-Stripped Multifunctional Wedge and Pyramid Arrays for Magnetic Nanofocusing and Optical Sensing.

    Science.gov (United States)

    Kumar, Shailabh; Johnson, Timothy W; Wood, Christopher K; Qu, Tao; Wittenberg, Nathan J; Otto, Lauren M; Shaver, Jonah; Long, Nicholas J; Victora, Randall H; Edel, Joshua B; Oh, Sang-Hyun

    2016-04-13

    We present large-scale reproducible fabrication of multifunctional ultrasharp metallic structures on planar substrates with capabilities including magnetic field nanofocusing and plasmonic sensing. Objects with sharp tips such as wedges and pyramids made with noble metals have been extensively used for enhancing local electric fields via the lightning-rod effect or plasmonic nanofocusing. However, analogous nanofocusing of magnetic fields using sharp tips made with magnetic materials has not been widely realized. Reproducible fabrication of sharp tips with magnetic as well as noble metal layers on planar substrates can enable straightforward application of their material and shape-derived functionalities. We use a template-stripping method to produce plasmonic-shell-coated nickel wedge and pyramid arrays at the wafer-scale with tip radius of curvature close to 10 nm. We further explore the magnetic nanofocusing capabilities of these ultrasharp substrates, deriving analytical formulas and comparing the results with computer simulations. These structures exhibit nanoscale spatial control over the trapping of magnetic microbeads and nanoparticles in solution. Additionally, enhanced optical sensing of analytes by these plasmonic-shell-coated substrates is demonstrated using surface-enhanced Raman spectroscopy. These methods can guide the design and fabrication of novel devices with applications including nanoparticle manipulation, biosensing, and magnetoplasmonics.

  8. A dual wedge microneedle for sampling of perilymph solution via round window membrane.

    Science.gov (United States)

    Watanabe, Hirobumi; Cardoso, Luis; Lalwani, Anil K; Kysar, Jeffrey W

    2016-04-01

    Precision medicine for inner-ear disease is hampered by the absence of a methodology to sample inner-ear fluid atraumatically. The round window membrane (RWM) is an attractive portal for accessing cochlear fluids as it heals spontaneously. In this study, we report on the development of a microneedle for perilymph sampling that minimizes the size of RWM perforation, facilitates quick aspiration, and provides precise volume control. Here, considering the mechanical anisotropy of the RWM and hydrodynamics through a microneedle, a 31G stainless steel pipe was machined into wedge-shaped design via electrical discharge machining. The sharpness of the needle was evaluated via a surface profilometer. Guinea pig RWM was penetrated in vitro, and 1 μL of perilymph was sampled and analyzed via UV-vis spectroscopy. The prototype wedge shaped needle was successfully fabricated with the tip curvature of 4.5 μm and the surface roughness of 3.66 μm in root mean square. The needle created oval perforation with minor and major diameter of 143 and 344 μm (n = 6). The sampling duration and standard deviation of aspirated volume were 3 s and 6.8 % respectively. The protein concentration was 1.74 mg/mL. The prototype needle facilitated precise perforation of RWMs and rapid aspiration of cochlear fluid with precise volume control. The needle design is promising and requires testing in human cadaveric temporal bone and further optimization to become clinically viable.

  9. 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)

  10. 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...

  11. Computational Analysis of Arc-Jet Wedge Tests Including Ablation and Shape Change

    Science.gov (United States)

    Goekcen, Tahir; Chen, Yih-Kanq; Skokova, Kristina A.; Milos, Frank S.

    2010-01-01

    Coupled fluid-material response analyses of arc-jet wedge ablation tests conducted in a NASA Ames arc-jet facility are considered. These tests were conducted using blunt wedge models placed in a free jet downstream of the 6-inch diameter conical nozzle in the Ames 60-MW Interaction Heating Facility. The fluid analysis includes computational Navier-Stokes simulations of the nonequilibrium flowfield in the facility nozzle and test box as well as the flowfield over the models. The material response analysis includes simulation of two-dimensional surface ablation and internal heat conduction, thermal decomposition, and pyrolysis gas flow. For ablating test articles undergoing shape change, the material response and fluid analyses are coupled in order to calculate the time dependent surface heating and pressure distributions that result from shape change. The ablating material used in these arc-jet tests was Phenolic Impregnated Carbon Ablator. Effects of the test article shape change on fluid and material response simulations are demonstrated, and computational predictions of surface recession, shape change, and in-depth temperatures are compared with the experimental measurements.

  12. Microchip and wedge ion funnels and planar ion beam analyzers using same

    Science.gov (United States)

    Shvartsburg, Alexandre A; Anderson, Gordon A; Smith, Richard D

    2012-10-30

    Electrodynamic ion funnels confine, guide, or focus ions in gases using the Dehmelt potential of oscillatory electric field. New funnel designs operating at or close to atmospheric gas pressure are described. Effective ion focusing at such pressures is enabled by fields of extreme amplitude and frequency, allowed in microscopic gaps that have much higher electrical breakdown thresholds in any gas than the macroscopic gaps of present funnels. The new microscopic-gap funnels are useful for interfacing atmospheric-pressure ionization sources to mass spectrometry (MS) and ion mobility separation (IMS) stages including differential IMS or FAIMS, as well as IMS and MS stages in various configurations. In particular, "wedge" funnels comprising two planar surfaces positioned at an angle and wedge funnel traps derived therefrom can compress ion beams in one dimension, producing narrow belt-shaped beams and laterally elongated cuboid packets. This beam profile reduces the ion density and thus space-charge effects, mitigating the adverse impact thereof on the resolving power, measurement accuracy, and dynamic range of MS and IMS analyzers, while a greater overlap with coplanar light or particle beams can benefit spectroscopic methods.

  13. 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.

  14. Wedge cutting of mild steel by CO 2 laser and cut-quality assessment in relation to normal cutting

    Science.gov (United States)

    Yilbas, B. S.; Karatas, C.; Uslan, I.; Keles, O.; Usta, Y.; Yilbas, Z.; Ahsan, M.

    2008-10-01

    In some applications, laser cutting of wedge surfaces cannot be avoided in sheet metal processing and the quality of the end product defines the applicability of the laser-cutting process in such situations. In the present study, CO 2 laser cutting of the wedge surfaces as well as normal surfaces (normal to laser beam axis) is considered and the end product quality is assessed using the international standards for thermal cutting. The cut surfaces are examined by the optical microscopy and geometric features of the cut edges such as out of flatness and dross height are measured from the micrographs. A neural network is introduced to classify the striation patterns of the cut surfaces. It is found that the dross height and out of flatness are influenced significantly by the laser output power, particularly for wedge-cutting situation. Moreover, the cut quality improves at certain value of the laser power intensity.

  15. Temporal evolution of fO2 in the Mariana mantle wedge

    Science.gov (United States)

    Brounce, M. N.; Kelley, K. A.; Cottrell, E.

    2013-12-01

    The elevated oxygen fugacity (fO2) recorded by arc lavas appears to be linked to slab fluid influence globally and locally; however, many details regarding the capacity that slab fluids have to oxidize the mantle wedge remain unknown. At the time of subduction initiation, melts may be produced by a combination of decompression and fluid-fluxed melting and the role of flux melting may increase as the subduction zone matures (Reagan et al., 2010, G3 11(3)). Immediately prior to subduction initiation, the mantle presumably has fO2 and fluid concentrations similar to mid-ocean ridge (MOR) source mantle (near the quartz-fayalite-magnetite buffer, QFM, and relatively dry). As subduction zones mature, slab fluids may become more dominant in melt generation as evidenced by increases in fluid-mobile trace element signatures, but the fO2 of slab fluids and temporal changes in the fO2 of erupted basalt remains undocumented. The Mariana forearc southwest of Guam records the initiation of Pacific plate subduction (Reagan et al., 2010). At the base, fore-arc basalts (FAB) erupted at the immediate onset of subduction (51-52 Ma) show minor traces of slab fluid influence and likely reflect decompression melting that occurred as mantle rose to accommodate the sinking Pacific plate. The FAB are overlain by 37-44 Ma 'transitional' basalts whose fluid mobile trace element enrichments indicate that slab fluids have greater influence in their petrogenesis. These lavas provide the opportunity to directly constrain the timescales of mantle wedge oxidation during the initiation and maturation of an oceanic subduction zone. We present Fe3+/ΣFe ratios (μ-XANES) determined on FAB and transitional basalt glasses, paired with previously published major and trace element data. These glasses range in MgO from 2.75 - 7.56 wt% and have Fe3+/ΣFe ratios (0.171 - 0.208) that are slightly more oxidized than MORB (0.16), similar to Mariana trough lavas that reflect minor traces of slab fluid influence

  16. Coulomb theory applied to accretionary and nonaccretionary wedges: Possible causes for tectonic erosion and/or frontal accretion

    Science.gov (United States)

    Lallemand, Serge E.; Schnürle, Philippe; Malavieille, Jacques

    1994-06-01

    Based on observations from both modem convergent margins and sandbox modeling, we examine the possible conditions favoring frontal accretion and/or frontal and basal tectonic erosion. Mean characteristic parameters (μ, μ*b and λ) are used to discuss the mechanical stability of 28 transects across the frontal part of convergent margins where the Coulomb theory is applicable. Natural observations reveal that "typical accretionary wedges" are characterized by low tapers with smooth surface slope and subducting plate, low convergence rates and thick trench sediment, while "nonaccretionary wedges" display large tapers with irregular surface slopes and rough subducting plate, high convergence rates and almost no trench fill. Sandbox experiments were performed to illustrate the effects of seamounts/ridges in the subduction zone on the deformation of an accretionary wedge. These experiments show that a wedge of sand is first trapped and pushed in front of the seamount which acts as a moving bulldozer. This is followed by a tunnelling effect of the subducting seamount through the frontal wedge material, which results in considerable sand reworking. At an advanced subduction stage, the décollement jumps back from a high level in the wedge to its former basal position. We conclude that a high trench sedimentation rate relative to the convergence rate leads to frontal accretion. In contrast, several conditions may favor tectonic erosion of the upper plate. First, oceanic features, such as grabens, seamounts or ridges, may trap upper plate material during their subduction process. Second, destabilization of the upper plate material by internal fluid overpressuring causing hydrofracturing is probably another important mechanism.

  17. DYNAMICS OF FREIGHT CARS ON BOGIES MODEL 18-1711 WITH DIFFERENT WEDGE DE-SIGNS OF SPRING SUSPENSION

    Directory of Open Access Journals (Sweden)

    N. B. Mankevych

    2014-01-01

    Full Text Available Purpose. To analyze the results of the study of dynamic parameters of a gondola car, model 12-1704-04 with axle load 23.5 ton in bogies, models 18-1750 and two gondola cars, model 12-1905 with axial load of 25 ton, one of which is equipped with bogies, model 18-1711 with friction wedges of spring suspension with spatial form with increased angle to the horizontal line of intersection of the contact surfaces between the wedge and bolster, the other gondola car, model 12-1905 is equipped with bogies of the same model on which the friction wedges fitted with a flat form of contact surface. It has an angle of inclination like a wedge of bogie, model 18-100. On the basis of the obtained results to draw conclusions about the feasibility of unification design bogie bolster, model 18-1711 with bogie, model 18-100 by contact surfaces with elements of spring suspension. Methodology. Research on dynamic performance of cars was performed during running dynamic tests of specimens of freight cars in experimental train consisting of two locomotives, a laboratory, and three gondola cars of the above mentioned models. Findings. Main results of dynamic studies are presented as graphs of indicators on the speed of the train and the experimental evidence that the freight gondola cars on bogies, model 18-1711 with flat-shaped wedges, in most cases are better than the others. Originality. Research results of cars on bogies, model 18-1711 were obtained. They let assess the dependence of the dynamic performance of the car from the design of the friction wedges of spring suspension. Practical value. Cast parts of bogie, model 18-1711 with 25 ton axle load can be used as a replacement of defective parts of bogie, model 18-100 and its analogs.

  18. 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

  19. Numerical Simulation on Ramp Initiation and Propagation in a Fold-and-thrust Belt and Accretionary Wedge

    Science.gov (United States)

    Hu, C.; Liu, X.; Shi, Y.

    2015-12-01

    Fold-and-thrust belts and accretionary wedge develop along compressive plate boundaries, both in hinterland and foreland. Under the long-term compressive tectonic loading, a series ramps will initiate and propagate along the wedge. How do the ramps initiate? What are the timing and spacing intervals between the ramps? How many patterns are there for the ramp propagation? These questions are basic for the study of ramp initiation and propagation. Many scholars used three different methods, critical coulomb wedge theory, analogue sandbox models, and numerical simulation to research the initiation and propagation of the ramps, respectively. In this paper, we set up a 2-D elastic-plastic finite element model, with a frictional contact plane, to simulate the initiation and propagation of the ramps. In this model, the material in upper wedge is homogenous, but considering the effects of gravity and long-term tectonic loading. The model is very simple but simulated results are very interesting. The simulated results indicate that the cohesion of upper wedge and dip angle of detachment plane have strong effects on the initiation and propagation of ramps. There are three different patterns of ramp initiation and propagation for different values of the cohesion. The results are different from those by previous analogue sandbox models, and numerical simulation, in which there is usually only one pattern for the ramp initiation and propagation. The results are consistent with geological survey for the ramp formation in an accretionary wedge. This study will provide more knowledge of mechanism of the ramp initiation and propagation in Tibetan Plateau and central Taiwan.

  20. Structural basis for Smoothened regulation by its extracellular domains

    Science.gov (United States)

    Miller, Paul S.; Hedger, George; Luchetti, Giovanni; Nachtergaele, Sigrid; Tully, Mark D.; Mydock-McGrane, Laurel; Covey, Douglas F.; Rambo, Robert P.; Sansom, Mark S. P.; Rohatgi, Rajat; Siebold, Christian

    2016-01-01

    Developmental signals of the Hedgehog (Hh) and Wnt families are transduced across the membrane by Frizzled-class G-protein coupled receptors (GPCRs) composed of both a heptahelical transmembrane domain (TMD) and an extracellular cysteine-rich domain (CRD). How such large extracellular domains of GPCRs regulate signalling by the TMD is unknown. We present crystal structures of the Hh signal transducer and oncoprotein Smoothened (SMO), which contains two distinct ligand-binding sites in its TMD and CRD. The CRD is stacked atop the TMD, separated by an intervening wedge-like linker domain (LD). Structure-guided mutations show that the interface between the CRD, LD and TMD stabilises the inactive state of SMO. Unexpectedly, we find a cholesterol molecule bound to SMO in the CRD-binding site. Mutations predicted to prevent cholesterol binding impair the ability of SMO to transmit native Hh signals. Binding of a clinically used antagonist, vismodegib, to the TMD induces a conformational change that is propagated to the CRD, resulting in loss of cholesterol from the CRD-LD-TMD interface. Our work elucidates the structural mechanism by which the activity of a GPCR is controlled by ligand-regulated interactions between its extracellular and transmembrane domains. PMID:27437577

  1. 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)

  2. 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

    PURPOSE: Our purpose was to evaluate the 3-year clinical results of patients with medial-compartment osteoarthritis of the knee and varus malalignment who underwent open-wedge high tibial osteotomy (HTO) with an internal plate fixator (TomoFix; Synthes, Solothurn, Switzerland). Clinical results...... of patients reported discomfort related to the implant at some point during the follow-up period (40.6%). CONCLUSIONS: Open-wedge osteotomy by use of the TomoFix system leads to reliable 3-year results. Results do not depend on the severity of medial cartilage defects, whereas partial-thickness defects...

  3. Mixed convection flow over a stretching porous wedge with Newtonian heating in the presence of heat generation or absorption

    Science.gov (United States)

    Ashraf, M.; Narahari, Marneni; Muthuvalu, Mohana Sundaram

    2016-11-01

    Time independent mixed convective boundary layer flow of a viscous fluid over a porous stretching wedge is investigated analytically. The porous wedge is subjected to Newtonian heating in the existence of heat generation /absorption. Employing non-dimensional transformations the governing PDE's converted to nonlinear ODE's which are further solved by using homotopy analysis method. The convergence of the solution is properly checked and the effects of various involved parameters on velocity and temperature distributions are illustrated through graphs. The reliability and effectiveness of HAM have been verified by comparing the present analytical results with existing numerical results for skin-friction coefficient. The results are found to be in good agreement.

  4. Domains via Graphs

    Institute of Scientific and Technical Information of China (English)

    ZHANG Guoqiang; CHEN Yixiang

    2001-01-01

    This paper provides a concrete and simple introduction to two pillars of domain theory: (1) solving recursive domain equations, and (2) universal and saturated domains. Our exposition combines Larsen and Winskel's idea on solving domain equations using information systems with Girard's idea of stable domain theory in the form of coherence spaces, or graphs.Detailed constructions are given for universal and even homogeneous objects in two categories of graphs: one representing binary complete, prime algebraic domains with complete primes covering the bottom; the other representing ω-algebraic, prime algebraic lattices. The backand-forth argument in model theory helps to enlighten the constructions.

  5. 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

  6. Wedge Versus Core Biopsy at Time Zero: Which Provides Better Predictive Value for Delayed Graft Function With the Remuzzi Histological Scoring System?

    Science.gov (United States)

    Yong, Z Z; Aitken, E L; Khan, K H; Kingsmore, D B

    2015-01-01

    Histopathological features on time-zero renal biopsies correlate with graft outcome after renal transplantation. With increasing numbers of marginal donors, assessment of pre-implantation graft quality is essential. The clinician's choice of wedge or core biopsy is performed without evidence of efficacy or safety. This study aims to compare the information derived from wedge biopsy versus core biopsy. Prospective evaluation of 37 wedge biopsies and 30 core biopsies was performed. Histopathological data were collected on number of glomeruli and arterioles observed, and Remuzzi scoring for glomerulosclerosis, tubular atrophy, interstitial fibrosis, and arteriolar narrowing was performed. Clinical data on delayed graft function (DGF) were also collated. Sensitivity, specificity, and positive and negative predictive values for DGF were compared. Patient demographics between the two cohorts were comparable. No complications of biopsies occurred; 81% of wedge biopsies versus 50% of core biopsies had >10 glomeruli (P = .01), whereas 32% of wedge biopsies and 57% of core biopsies had >2 arterioles (P = .02). Wedge biopsies were more likely to identify pathology with more glomerulosclerosis, tubular atrophy (P value of Remuzzi ≥ 4 for predicting DGF was better on wedge biopsy (45.5% versus 0%; P core biopsies for identifying clinically significant histopathological findings on pre-implantation renal biopsy. We believe that the wedge biopsy is the method of choice for time-zero biopsies. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Beam data measurements for dynamic wedges on Varian 600C (6 MV) and 2100C (6 and 10 MV) linear accelerators.

    Science.gov (United States)

    Bidmead, A M; Garton, A J; Childs, P J

    1995-03-01

    The measurement of beam data for dynamic wedge dosimetry requires the integration of radiation dose at points across the radiation field during the dose delivery. The different measurement techniques required when using a linear diode array to measure beam profiles and when using ionization chambers to measure depth doses and effective wedge factors are described. The segmented treatment tables (STTS), which specify the delivered dose as a function of jaw position, are used by the control algorithm to deliver dynamic wedge fields. The reproducibility achieved using STTS is very consistent (and the stability of the accelerators is very good) so there is no significant variation in effective wedge factor or profile shape. There is a unique set of 132 STTS for each energy and design of treatment machine, which encompasses all the dynamic wedge data. There are significant discontinuities of up to 14% in wedge factors at certain field sizes. This means that wedge factors have to be measured at small increments (0.5 cm) in field size, as it is the width of the dynamic wedge field that determines the STT used. Considerable care must be taken when implementing these data on a current generation treatment planning computer.

  8. Thrust fault growth within accretionary wedges: New Insights from 3D seismic reflection data

    Science.gov (United States)

    Orme, H.; Bell, R. E.; Jackson, C. A. L.

    2015-12-01

    The shallow parts of subduction megathrust faults are typically thought to be aseismic and incapable of propagating seismic rupture. The 2011 Tohoku-Oki earthquake, however, ruptured all the way to the trench, proving that in some locations rupture can propagate through the accretionary wedge. An improved understanding of the structural character and physical properties of accretionary wedges is therefore crucial to begin to assess why such anomalously shallow seismic rupture occurs. Despite its importance, we know surprisingly little regarding the 3D geometry and kinematics of thrust network development in accretionary prisms, largely due to a lack of 3D seismic reflection data providing high-resolution, 3D images of entire networks. Thus our current understanding is largely underpinned by observations from analogue and numerical modelling, with limited observational data from natural examples. In this contribution we use PSDM, 3D seismic reflection data from the Nankai margin (3D Muroto dataset, available from the UTIG Academic Seismic Portal, Marine Geoscience Data System) to examine how imbricate thrust fault networks evolve during accretionary wedge growth. Previous studies have reported en-echelon thrust fault geometries from the NW part of the dataset, and have related this complex structure to seamount subduction. We unravel the evolution of faults within the protothrust and imbricate thrust zones by interpreting multiple horizons across faults and measuring fault displacement and fold amplitude along-strike; by doing this, we are able to investigate the three dimensional accrual of strain. We document a number of local displacement minima along-strike of faults, suggesting that, the protothrust and imbricate thrusts developed from the linkage of smaller, previously isolated fault segments. We also demonstrate that the majority of faults grew upward from the décollement, although there is some evidence for downward fault propagation. Our observations

  9. 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

  10. Crystallization of soft matter under confinement at interfaces and in wedges

    Science.gov (United States)

    Archer, Andrew J.; Malijevský, Alexandr

    2016-06-01

    The surface freezing and surface melting transitions that are exhibited by a model two-dimensional soft matter system are studied. The behaviour when confined within a wedge is also considered. The system consists of particles interacting via a soft purely repulsive pair potential. Density functional theory (DFT) is used to calculate density profiles and thermodynamic quantities. The external potential due to the confining walls is modelled via a hard wall with an additional repulsive Yukawa potential. The surface phase behaviour depends on the range and strength of this repulsion: when the repulsion is weak, the wall promotes freezing at the surface of the wall. The thickness of this frozen layer grows logarithmically as the bulk liquid-solid phase coexistence is approached. Our mean-field DFT predicts that this crystalline layer at the wall must be nucleated (i.e. there is a free energy barrier) and its formation is necessarily a first-order transition, referred to as ‘prefreezing’, by analogy with the prewetting transition. However, in contrast to the latter, prefreezing cannot terminate in a critical point, since the phase transition involves a change in symmetry. If the wall-fluid interaction is sufficiently long ranged and the repulsion is strong enough, surface melting can occur instead. Then the interface between the wall and the bulk crystalline solid is wetted by the liquid phase as the chemical potential is decreased towards the value at liquid-solid coexistence. It is observed that the finite thickness fluid film at the wall has a broken translational symmetry due to its proximity to the bulk crystal, and so the nucleation of the wetting film can be either first order or continuous. Our mean-field theory predicts that for certain wall potentials there is a premelting critical point analogous to the surface critical point for the prewetting transition. When the fluid is confined within a linear wedge, this can strongly promote freezing when the

  11. Big mantle wedge, anisotropy, slabs and earthquakes beneath the Japan Sea

    Science.gov (United States)

    Zhao, Dapeng

    2017-09-01

    The Japan Sea is a part of the western Pacific trench-arc-backarc system and has a complex bathymetry and intense seismic activities in the crust and upper mantle. Local seismic tomography revealed strong lateral heterogeneities in the crust and uppermost mantle beneath the eastern margin of the Japan Sea, which was determined using P and S wave arrival times of suboceanic earthquakes relocated precisely with sP depth phases. Ambient-noise tomography revealed a thin crust and a thin lithosphere beneath the Japan Sea and significant low-velocity (low-V) anomalies in the shallow mantle beneath the western and eastern margins of the Japan Sea. Observations with ocean-bottom seismometers and electromagnetometers revealed low-V and high-conductivity anomalies at depths of 200-300 km in the big mantle wedge (BMW) above the subducting Pacific slab, and the anomalies are connected with the low-V zone in the normal mantle wedge beneath NE Japan, suggesting that both shallow and deep slab dehydrations occur and contribute to the arc and back-arc magmatism. The Pacific slab has a simple geometry beneath the Japan Sea, and earthquakes occur actively in the slab down to a depth of ∼600 km beneath the NE Asian margin. Teleseismic P and S wave tomography has revealed that the Philippine Sea plate has subducted aseismically down to the mantle transition zone (MTZ, 410-660 km) depths beneath the southern Japan Sea and the Tsushima Strait, and a slab window is revealed within the aseismic Philippine Sea slab. Seismic anisotropy tomography revealed a NW-SE fast-velocity direction in the BMW, which reflects corner flows induced by the fast deep subduction of the Pacific slab. Large deep earthquakes (M > 7.0; depth > 500 km) occur frequently beneath the Japan Sea western margin, which may be related to the formation of the Changbai and Ulleung intraplate volcanoes. A metastable olivine wedge is revealed within the cold core of the Pacific slab at the MTZ depth, which may be related

  12. Upper crustal mechanical stratigraphy and the evolution of thrust wedges: insights from sandbox analogue experiments

    Science.gov (United States)

    Milazzo, Flavio; Storti, Fabrizio; Nestola, Yago; Cavozzi, Cristian; Magistroni, Corrado; Meda, Marco; Salvi, Francesca

    2016-04-01

    Crustal mechanical stratigraphy i.e. alternating mechanically weaker and stronger layers within the crust, plays a key role in determining how contractional deformations are accommodated at convergent plate boundaries. In the upper crust, evaporites typically provide preferential décollement layers for fault localization and foreland ward propagation, thus significantly influencing evolution of thrust-fold belts in terms of mechanical balance, geometries, and chronological sequences of faulting. Evaporites occur at the base of many passive margin successions that underwent positive inversion within orogenic systems. They typically produce salient geometries in deformation fronts, as in the Jura in the Northern Alps, the Salakh Arch in the Oman Mountains, or the Ainsa oblique thrust-fold belt in the Spanish Pyrenees. Evaporites frequently occur also in foredeep deposits, as in the Apennines, the Pyrenees, the Zagros etc. causing development of additional structural complexity. Low-friction décollement layers also occur within sedimentary successions involved in thrust-fold belts and they contribute to the development of staircase fault trajectories. The role of décollement layers in thrust wedge evolution has been investigated in many experimental works, particularly by sandbox analogue experiments that have demonstrated the impact of basal weak layers on many first order features of thrust wedges, including the dominant fold vergence, the timing of fault activity, and the critical taper. Some experiments also investigated on the effects of weak layers within accreting sedimentary successions, showing how this triggers kinematic decoupling of the stratigraphy above and below the décollements, thus enhancing disharmonic deformation. However, at present a systematic experimental study of the deformation modes of an upper crustal mechanical stratigraphy consisting of both low-friction and viscous décollement layers is still missing in the specific literature. In

  13. 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.

  14. Domains of laminin

    DEFF Research Database (Denmark)

    Engvall, E; Wewer, U M

    1996-01-01

    Extracellular matrix molecules are often very large and made up of several independent domains, frequently with autonomous activities. Laminin is no exception. A number of globular and rod-like domains can be identified in laminin and its isoforms by sequence analysis as well as by electron...... microscopy. Here we present the structure-function relations in laminins by examination of their individual domains. This approach to viewing laminin is based on recent results from several laboratories. First, some mutations in laminin genes that cause disease have affected single laminin domains, and some...... laminin isoforms lack particular domains. These mutants and isoforms are informative with regard to the activities of the mutated and missing domains. These mutants and isoforms are informative with regard to the activities of the mutated and missing domains. Second, laminin-like domains have now been...

  15. Thermal partition function of photons and gravitons in a Rindler wedge

    CERN Document Server

    Iellici, D; Iellici, Devis; Moretti, Valter

    1996-01-01

    The thermal partition function of photons in any covariant gauge and gravitons in the harmonic gauge, propagating in a Rindler wedge, are computed using a local zeta-function regularization approach. The correct Planckian leading order temperature dependence T^4 is obtained in both cases. For the photons, it is confirmed the existence of a surface term giving a negative contribution to the entropy, as earlier obtained by D.Kabat, but this term is shown to be gauge-dependent in the four dimensional case and therefore discarded. It is argued that similar terms could appear dealing with any integer spin s\\geq 1 in the massless case and in more general manifolds. Our conjecture is checked in the case of a graviton in the harmonic gauge, where different surface terms also appear, and physically consistent results arise dropping these terms. The results are discussed in relation to the quantum corrections to the black-hole entropy.

  16. The Wedge Splitting Test: Influence of Aggregate Size and Water-to-Cement Ratio

    DEFF Research Database (Denmark)

    Pease, Bradley Justin; Skocek, Jan; Geiker, Mette Rica;

    2007-01-01

    of various concrete mixtures there are limitations to the current analysis techniques. To date these techniques analyze the result of one WST specimen, thereby providing an estimate of material properties from single result. This paper utilizes a recent improvement to the inverse analysis technique, which......Since the development of the wedge splitting test (WST), techniques have been used to extract material properties that can describe the fracture behavior of the tested materials. Inverse analysis approaches are commonly used to estimate the stress-crack width relationship; which is described...... by the elastic modulus, tensile strength, fracture energy, and the assumed softening behavior. The stress-crack width relation can be implemented in finite element models for computing the cracking behavior of cementitious systems. While inverse analysis provides information about the material properties...

  17. Casimir-Polder repulsion near edges: wedge apex and a screen with an aperture

    CERN Document Server

    Milton, Kimball A; Parashar, Prachi; Pourtolami, Nima; Brevik, Iver; Ellingsen, Simen A

    2011-01-01

    Although repulsive effects have been predicted for quantum vacuum forces between bodies with nontrivial electromagnetic properties, such as between a perfect electric conductor and a perfect magnetic conductor, realistic repulsion seems difficult to achieve. Repulsion is possible if the medium between the bodies has a permittivity in value intermediate to those of the two bodies, but this may not be a useful configuration. Here, inspired by recent numerical work, we initiate analytic calculations of the Casimir-Polder interaction between an atom with anisotropic polarizability and a plate with an aperture. In particular, for a semi-infinite plate, and, more generally, for a wedge, the problem is exactly solvable, and for sufficiently large anisotropy, Casimir-Polder repulsion is indeed possible, in agreement with the previous numerical studies. In order to achieve repulsion, what is needed is a sufficiently sharp edge (not so very sharp, in fact) so that the directions of polarizability of the conductor and t...

  18. Analysis of Metal Forming in Two-Roll Cross Wedge Rolling Process Using Finite Element Method

    Institute of Scientific and Technical Information of China (English)

    WANG Min-ting; LI Xue-tong; DU Feng-shan

    2009-01-01

    A simulation model for two-roll cross wedge rolling (CWR) was presented by using three-dimensional rigid-plastic finite element method (FEM).The whole forming process of CWR,including knifing zone,guiding zone,stretching zone,and sizing zone,was simulated using the model in which dynamic adaptive remeshing technology for tetrahedral solid elements was used to fix element distortion.Based on the simulation results,the distributions of metal flow field,strain field,and damage field,and the geometry of the workpiece's end were analyzed.These results could provide theoretical guidance for realizing net shaping and reasonable design of tools.

  19. Shielding effect of a nano-circular inclusion acting on semi-infinite wedge cracks

    Institute of Scientific and Technical Information of China (English)

    Song Hao-Peng; Gao Cun-Fa

    2013-01-01

    The model of a screw dislocation near a semi-infinite wedge crack tip inside a nano-circular inclusion is proposed to investigate the shielding effect of nano inclusions acting on cracks.Utilizing the complex function method,the closed-form solutions of the stress fields in the matrix and the inclusion region are derived.The stress intensity factor,the image force,as well as the critical loads for dislocation emission are discussed in detail.The results show that the nano inclusion not only enhances the shielding effect exerted by the dislocation,but also provides a shielding effect itself.Moreover,dislocations may be trapped in the nano inclusion even if the matrix is softer than the inclusion.This helps the dislocation shield crack,and reduces the dislocation density within the matrix.

  20. Synergistic effect of a new wedge-bond-type anchor for CFRP tendons

    Institute of Scientific and Technical Information of China (English)

    谢桂华; 刘荣桂; 陈蓓; 李明君; 石天罡

    2015-01-01

    In order to improve the anchoring force of anchors for carbon fiber reinforced polymer (CFRP) tendons further, a new wedge-bond-type anchor for CFRP tendons was developed. The increment in anchoring force induced by the clamping segment of anchor was studied. Taking the deformation of all parts in clamping segment in the transverse direction into consideration, the calculation formula for the increment of anchoring force was proposed based on the linear elastic hypotheses. The proposed model is verified by experiments and conclusions are drawn that the anchoring force is influenced mainly by the inclination angle of clamping pieces, the length of clamping part and the thickness of bonding medium. Especially, the thickness of bonding medium should be lowered in design to improve the synergistic effect of anchors.

  1. Benchmarking the Sandbox: Quantitative Comparisons of Numerical and Analogue Models of Brittle Wedge Dynamics (Invited)

    Science.gov (United States)

    Buiter, S.; Schreurs, G.; Geomod2008 Team

    2010-12-01

    When numerical and analogue models are used to investigate the evolution of deformation processes in crust and lithosphere, they face specific challenges related to, among others, large contrasts in material properties, the heterogeneous character of continental lithosphere, the presence of a free surface, the occurrence of large deformations including viscous flow and offset on shear zones, and the observation that several deformation mechanisms may be active simultaneously. These pose specific demands on numerical software and laboratory models. By combining the two techniques, we can utilize the strengths of each individual method and test the model-independence of our results. We can perhaps even consider our findings to be more robust if we find similar-to-same results irrespective of the modeling method that was used. To assess the role of modeling method and to quantify the variability among models with identical setups, we have performed a direct comparison of results of 11 numerical codes and 15 analogue experiments. We present three experiments that describe shortening of brittle wedges and that resemble setups frequently used by especially analogue modelers. Our first experiment translates a non-accreting wedge with a stable surface slope. In agreement with critical wedge theory, all models maintain their surface slope and do not show internal deformation. This experiment serves as a reference that allows for testing against analytical solutions for taper angle, root-mean-square velocity and gravitational rate of work. The next two experiments investigate an unstable wedge, which deforms by inward translation of a mobile wall. The models accommodate shortening by formation of forward and backward shear zones. We compare surface slope, rate of dissipation of energy, root-mean-square velocity, and the location, dip angle and spacing of shear zones. All models show similar cross-sectional evolutions that demonstrate reproducibility to first order. However

  2. Commissioning Varian enhanced dynamic wedge in the PINNACLE treatment planning system using Gafchromic EBT film.

    Science.gov (United States)

    Fontanarosa, Davide; Orlandini, Lucia Clara; Andriani, Italo; Bernardi, Luca

    2009-10-01

    In external photon beam therapies, the technique of dynamic wedge is a well established method for dose inhomogeneity compensation. The introduction of the enhanced dynamic wedge (EDW) on Varian LINACs considerably improved the pre-existing techniques. In the process of commissioning a Varian LINAC into a PINNACLE3 treatment planning system (TPS), the user is required to import quite a few measurements of EDW profiles and percentage depth doses (PDDs). Standard measurement devices like ionization chambers in a water phantom are not the most indicated ones for this situation where each measurement point is obtained by integrating during the entire exposure: Measurements would result to be a very laborious and time consuming operation, most of the times not practically possible. The goal of the present work is to introduce an alternative and hands-on procedure to perform the measurements using a combination of GafchromicTM EBT films, irradiated sideways in one single shot for both profiles and PDDs, and a single standard ionization chamber. The scanned profiles obtained at different depths have easily been imported in the TPS; for the PDD measurements, a correction was proven necessary to account for a "self-shielding" effect introduced by the presence of the films themselves, when irradiated sideways, resulting in an underestimation of the dose at deeper depths. A correction curve was derived comparing TPS open field validated measurements with the curves extracted from GafchromicTM EBT films. Finally, the curve was applied to all the wedged fields PDD measurements and could minimize the errors. The comparison for the 15 MV photon beam between the measured and the calculated 48 profiles and 12 PDDs (field sizes from 5 x 5 to 20 x 20 cm2, wedge angles ranging from 15 degrees to 60 degrees) was acceptable. The confidence limit (CL) was used as fit indicator, as suggested by the ESTRO Booklet No. 7: For the investigated PDDs the maximum value was 6.40 in the build up

  3. The process parameters effect of ovality in cross wedge rolling for hollow valve without mandril

    Directory of Open Access Journals (Sweden)

    Ji Hongchao

    2016-01-01

    Full Text Available This paper presents the experimental and numerical results of the effect process parameters on ovality in cross wedge rolling (CWR for hollow engine valve without mandrel. Numerical simulation model for ovality was established by means of the rigid-plastic finite element modeling (FEM method for hollow engine valve. The experiments and numerical analyses suggest that the following parameters represent the best conditions for CWR of hollow engine valve: 30°-34° for the forming angle(α, 5°-7° for the stretching angle(β, 0.2-0.3mm for the mold void width(L, and 65%-70% for the area reduction(Ψ.

  4. 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%.

  5. Double-wedged Wollaston-type polarimeter design and integration to RTT150-TFOSC

    Science.gov (United States)

    Helhel, Selcuk; Kirbiyik, Halil; Bayar, Cevdet; Khamitov, Irek; Kahya, Gizem; Okuyan, Oguzhan

    2016-07-01

    Photometric and spectroscopic observation capabilities of 1.5-m Russian- Turkish Telescope RTT150 has been broadened with the integration of presented polarimeter. The well-known double-wedged Wollaston-type dual-beam technique was preferred and applied to design and produce it. The designed polarimeter was integrated into the telescope detector TFOSC, and called TFOSC-WP. Its capabil- ities and limitations were attempted to be determined by a number of observation sets. Non-polarized and strongly polarized stars were observed to determine its limi- tations as well as its linearity. An instrumental intrinsic polarization was determined for the 1×5 arcmin field of view in equatorial coordinate system, the systematic error of polarization degree as 0.2% %, and position angle as 1.9°. These limitations and capabilities are denoted as good enough to satisfy telescopes' present and future astrophysical space missions related to GAIA and SRG projects.

  6. 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)

  7. [Medial closing wedge osteotomy for correction of genu valgum and torsional malalignment].

    Science.gov (United States)

    Petersen, W; Forkel, P

    2013-12-01

    Femoral medial closing wedge osteotomy for the correction of valgus malalignment to unload the cartilage in the lateral compartment and/or correction of symptomatic torsional malalignment. Lateral unicompartmental osteoarthritis of the knee with genu valgum in young patients. Symptomatic torsional malalignement of > 30° and genu valgum with medial closing osteotomy of the distal femur (6 men and 17 women). After 3.5-years follow-up, the KOOS increased from 48.4 points to 84.9 points. In one case, there was an early loss of correction, with subsequent revision with bone grafting and lateral osteosynthesis. No peri-or postoperative complications such as infection, thrombosis, and embolism occurred. In 5 cases a torsional osteotomy was performed. The torsional osteotomy was performed 4 times due to chronic patellofemoral instability, and once due to a medial tibiofemoral instability. Healing complications were not observed in this population. Recurrent instability was not observed.

  8. Electric currents of a substorm current wedge on 24 February 2010

    Science.gov (United States)

    Connors, Martin; McPherron, Robert L.; Anderson, Brian J.; Korth, Haje; Russell, Christopher T.; Chu, Xiangning

    2014-07-01

    The three-dimensional "substorm current wedge" (SCW) was postulated by McPherron et al. (1973) to explain substorm magnetic perturbations. The origin and coherence as a physical system of this important paradigm of modern space physics remained unclear, however, with progress hindered by gross undersampling, and uniqueness problems in data inversion. Complementing AMPERE (Active Magnetosphere and Planetary Electrodynamics Response Experiment) space-derived radial electric currents with ground magnetic data allowing us to determine currents from the ionosphere up, we overcome problems of uniqueness identified by Fukushima (1969, 1994). For a substorm on 24 February 2010, we quantify SCW development consistently from ground and space data. Its westward electrojet carries 0.5 MA in the more poleward part of the auroral oval, in Region 1 (R1) sense spanning midnight. The evening sector electrojet also feeds into its upward current. We thus validate the SCW concept and obtain parameters needed for quantitative study of substorms.

  9. The role of subducting bathymetric highs on the oceanic crust to deformation of accretionary wedge and earthquake segmentation in the Java forearc

    Science.gov (United States)

    Singh, S. C.; Mukti, M.; Deighton, I.

    2014-12-01

    Stratigraphic and structural observations of newly acquired seismic reflection data along the offshore south Java reveal the structural style of deformation along the forearc and the role of subducting bathymetric highs to the morphology of the forearc region. The forearc region can be divided in to two major structural units: accretionary wedge and forearc and forearc basin where a backthrust marks the boundary between the accretionary wedge and the forearc basin sediments. The continuous compression in the subduction zone has induced younger landward-vergent folds and thrusts within the seaward margin of the forearc basin sediments, which together with the backthrust is referred as the Offshore South Java Fault Zone (OSJFZ), representing the growth of the accretionary wedge farther landward. Seaward-vergent imbricated thrusts have deformed the sediments in the accretionary wedge younging seaward, and have developed fold-thrust belts in the accretionary wedge toward trench. Together with the backthrusts, these seaward-vergent thrusts characterize the growth of accretionary wedge in South of Java trench. Based on these new results, we suggest that accretionary wedge mechanic is not the first order factor in shaping the morphology of the accretionary wedge complex. Instead the subducting bathymetric highs play the main role in shaping the forearc that are manifested in the uplift of the forearc high and intense deformation along the OSJFZ. These subducting highs also induce compression within the accretionary sediments, evident from landward deflection of the subduction front at the trench and inner part of accretionary wedge in the seaward margin of the forearc basin. Intense deformation is also observed on the seaward portion of the accretionary wedge area where the bathymetric highs subducted. We suggest that these subducted bathymetric features define the segment boundaries for megathrust earthquakes, and hence reducing the maximum size of the earthquakes in the

  10. Comparison between two angular stable locking plates for medial opening-wedge high tibial osteotomy: Decisive wedge locking plate versus TomoFix™.

    Science.gov (United States)

    Shin, Young-Soo; Kim, Keong-Ho; Sim, Hyun-Bo; Yoon, Jung-Ro

    2016-11-01

    An adequate stable fixation implant should be used for medial opening-wedge high tibial osteotomy (MOWHTO) to promote rapid bone healing without complications. This study compared the radiographic and clinical outcomes as well as plate-specific complications between two angular stable locking plates in patients following MOWHTO. This prospective study involved 97 patients (50 with DWL(®), group I; 47 with TomoFix™, group II) undergoing MOWHTO for primary medial compartment osteoarthritis between 2010 and 2013. Clinical and radiographic evaluations were performed by using the HSS and WOMAC scores, and calculating mechanical femorotibial angle (mFTA), medial proximal tibial angle (MPTA), joint line convergence angle (JLCA), and posterior tibial slope (PTS) on radiographs both preoperatively and after 3 years. A statistically significant difference was observed for the MPTA at the last follow-up between the two groups (P = 0.033). Additionally, the last follow-up MPTA of group I was associated with the osteotomy technique (P = 0.004) and preoperative JLCA (P = 0.034) whereas the last follow-up MPTA of group II was associated with gender (P = 0.001) and BMI (P = 0.008). Furthermore, the results showed that group I had a higher rate of non-union (4%) compared to that in group II (0%). Both locking plates are useful tools in the treatment of medial compartment knee osteoarthritis with varus deformity in young, active patients. However, under special consideration of the complication we found in present study, the TomoFix™ seems to be a better alternative in using the MOWHTO for highly demanding patients. Copyright © 2016 The Japanese Orthopaedic Association. Published by Elsevier B.V. All rights reserved.

  11. Osteotomy configuration of the proximal wedge and analysis of the affecting factors in the medial open-wedge high tibial osteotomy.

    Science.gov (United States)

    Lee, Yong Seuk; Kang, Jong Yeal; Lee, Myung Chul; Elazab, Ashraf; Choi, Uk Hyun; Kang, Seo Goo; Lee, Kyoung Jae; Lee, Sahnghoon

    2017-03-01

    The purposes of this study were (1) to confirm the disparity of the measured thickness at the lateral hinge between anterior-posterior (AP) radiograph and 3D CT image, (2) to evaluate the affecting factors, and (3) to evaluate the differences between uniplanar and biplanar osteotomies. From 2012 to 2014, a prospective comparative study was performed with 30 patients who received uniplanar osteotomy (group I) and 35 patients who received biplanar osteotomy (group II). For measurement of the proximal wedge, postoperative AP radiograph and 3D CT images were used. In the AP radiograph, medial and lateral bony bridge thicknesses were measured. In the 3D CT, the anterior and posterior images parallel to the coronal plane were selected for the evaluation. Coronal osteotomy slope was measured with the anterior image of the 3D CT scan. Sagittal osteotomy slope was measured with the sagittal section of the CT scan. Differences between the lateral bony bridge thicknesses measured in AP radiograph and the posterolateral posterolateral bony bridge thicknesses measured in 3D CT were statistically significant in both groups. Negative correlation was observed in the biplanar osteotomy group. Differences of the sagittal osteotomy slope from the native tibial slope showed negative correlation in the biplanar osteotomy group. Thickness of the posterolateral bony bridge was smaller compared to the observed thickness on the AP radiograph image that is routinely used for the follow-up. The thickness would be getting smaller if osteotomy is performed with an abrupt angle on the coronal plane and reverse slope on the sagittal plane. Therefore, osteotomy with abrupt angle on the coronal plane and reverse slope on the sagittal plane should be avoided for the proper thickness of the posterolateral bony bridge. III.

  12. Anatexis of accretionary wedge, Pacific-type magmatism, and formation of vertically stratified continental crust in the Altai Orogenic Belt

    Science.gov (United States)

    Jiang, Y. D.; Schulmann, K.; Sun, M.; Å típská, P.; Guy, A.; Janoušek, V.; Lexa, O.; Yuan, C.

    2016-12-01

    Granitoid magmatism and its role in differentiation and stabilization of the Paleozoic accretionary wedge in the Chinese Altai are evaluated in this study. Voluminous Silurian-Devonian granitoids intruded a greywacke-dominated Ordovician sedimentary succession (the Habahe Group) of the accretionary wedge. The close temporal and spatial relationship between the regional anatexis and the formation of granitoids, as well as their geochemical similarities including rather unevolved Nd isotopic signatures and the strong enrichment of large-ion lithophile elements relative to many of the high field strength elements, may indicate that the granitoids are product of partial melting of the accretionary wedge rocks. Whole-rock geochemistry and pseudosection modeling show that regional anatexis of fertile sediments could have produced a large amount of melts compositionally similar to the granitoids. Such process could have left a high-density garnet- and/or garnet-pyroxene granulite residue in the deep crust, which can be the major reason for the gravity high over the Chinese Altai. Our results show that melting and crustal differentiation can transform accretionary wedge sediments into vertically stratified and stable continental crust. This may be a key mechanism contributing to the peripheral continental growth worldwide.

  13. CALCULATION OF DISPLACEMENT FIELD AND DEFORMATIONS OF WEDGE SHAPED TWIN WITH THE HELP OF MESOSCOPIC DISLOCATIONAL MODEL

    Directory of Open Access Journals (Sweden)

    Y. V. Vasilevich

    2011-01-01

    Full Text Available Displacements and deformations of a wedge-shaped twin have been calculated with the help of mesoscopic dislocational model. It has been shown that deformations are localized at twin boundaries and twin top and also at some limited areas which are rather far from the twin. 

  14. Detection of elevated pulmonary capillary wedge pressure in elderly patients with various cardiac disorders by the Valsalva manoeuvre.

    NARCIS (Netherlands)

    Remmen, J.J.; Aengevaeren, W.R.M.; Verheugt, F.W.A.; Jansen, R.W.M.M.

    2006-01-01

    In the present study, we assessed whether elevated (> or =15 mmHg) PCWP (pulmonary capillary wedge pressure) can be detected using the blood pressure response to the Valsalva manoeuvre in a group of elderly patients with various cardiac disorders, including atrial fibrillation and valvular heart dis

  15. 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.

  16. 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.

  17. LBP and lower limb discrepancy: 3D evaluation of postural rebalancing via underfoot wedge correction.

    Science.gov (United States)

    D'Amico, Moreno; Roncoletta, Piero; Di Felice, Francesca; Porto, Daniele; Bellomo, Rosagrazia; Saggini, Raoul

    2012-01-01

    Leg Length Discrepancy (LLD) is very often associated to Low Back Pain (LBP), but still controversial is the use of underfoot wedge correction (heel rise) to re-balance pelvis and trunk posture. In a review of our last 5 years clinical activity we observed that more than 70% out of 300 LBP patients presented a LLD. In more than 80 % we ascertained, via Baropodography, the presence of underfoot asymmetric load, during standing. More durable therapy recovery effect has been observed when LLD correction had been adopted. These reasons led us to start a study to assess if a Full 3D multifactorial Posture evaluation approach, by means of Opto-electronic device associated to foot pressure maps recording, was able to quantitatively discriminate the clinically observed phenomena. On a 94 LBP (av. age 46.3±16 Y range 15-82 Y) patients sample, 83 (88%) have been found to improve posture when LLD was corrected. The 94 patients showed a mean lower limb discrepancy of μ=8±3.2mm associated to a mean scoliotic lumbar curve μ=10.5°±5.1° Cobb (frontal plane), mean Spinal offset μ=6.6±4.9mm and mean Global offset 10.7±8.8mm. The applied paired t-test comparison (indifferent vs. corrected orthostasis) showed significant (p < 0.05) postural improvements could be obtained in the whole or in a part of the considered parameters, both in rebalancing and in spine deformities reduction after the application of suitable under-foot wedge. The joint 3D opto-electronic and foot pressure map approach proved to be effective to control several clinical parameters with statistical significance.

  18. Fast-track rehabilitation following video-assisted pulmonary sublobar wedge resection: A prospective randomized study

    Directory of Open Access Journals (Sweden)

    Christos Asteriou

    2016-01-01

    Full Text Available Background: Postoperative morbidity and inhospital length of stay are considered major determinants of total health care expenditure associated with thoracic operations. The aim of this study was to prospectively evaluate the role of video-assisted thoracic surgery (VATS compared to mini-muscle-sparing thoracotomy in facilitating early recovery and hospital discharge after pulmonary sublobar wedge resections. Patients and Methods: A total number of 120 patients undergoing elective pulmonary sublobar wedge resection were randomly assigned to VATS (n = 60 or mini-muscle-sparing thoracotomy (n = 60. The primary endpoint was time to hospital discharge. Postoperative complications, cardiopulmonary morbidity and 30-day mortality served as secondary endpoints. Results: Patients' baseline demographic and clinical data did not differ among study arms as well as the number of pulmonary segments resected and the morphology of the nodular lesions. Total hospital stay was significantly shorter in patients assigned to the thoracoscopic technique as opposed to those who were operated using the mini-muscle-sparing thoracotomy approach (4 ± 0.6 versus 4.4 ± 0.6 days respectively, P = 0.006. Multivariate analysis revealed that VATS approach was inversely associated with longer inhospital stay whereas the number of resected segments was positively associated with an increased duration of hospitalization. Patients in the VATS group were less likely to develop atelectasis (≥1 lobe compared to those who underwent thoracotomy (0% versus 6.7% respectively, P = 0.042. Kaplan-Meier analysis revealed similar 30-day mortality rates in both study arms (Log-rank P = 0.560. Conclusion: VATS was associated with shorter duration of hospitalization positively affecting the patients' quality of life and satisfaction. Significant suppression of the total cost of recovery after thoracoscopic pulmonary resections is expected.

  19. Sagittal osteotomy inclination in medial open-wedge high tibial osteotomy.

    Science.gov (United States)

    Lee, Seung-Yup; Lim, Hong-Chul; Bae, Ji Hoon; Kim, Jae Gyoon; Yun, Se-Hyeok; Yang, Jae-Hyuk; Yoon, Jung-Ro

    2017-03-01

    Unlike postoperative changes in posterior tibial slope after medial open-wedge high tibial osteotomy, sagittal osteotomy inclination has not been examined. It has been recommended that the osteotomy line in the sagittal plane be parallel to the medial posterior tibial slope. The purpose of this study was to determine the frequency of parallel osteotomy in medial open-wedge high tibial osteotomy. To determine the sagittal osteotomy inclination, the angle between the medial joint line and the osteotomy line was measured in the lateral radiograph. A positive angle value indicates that the osteotomy is anteriorly inclined relative to the medial posterior tibial slope. Correlation between the sagittal osteotomy inclination and posterior tibial slope was also evaluated. The mean sagittal osteotomy inclination was 15.1 ± 7.5°. The majority 87.1 % of knees showed an anterior-inclined osteotomy. There was a significantly positive correlation between the postoperative posterior tibial slope and the sagittal osteotomy inclination (r, 0.33; 95 % confidence interval (CI) 0.19-0.46; P osteotomy inclination (r, 0.35; 95 % CI 0.21-0.47; P osteotomy in the sagittal plane relative to the medial joint line was planned, only 12.9 % of cases achieved osteotomy parallel to the medial posterior tibial slope in the sagittal plane. Because of high rate of the anterior-inclined osteotomy and their correlations with posterior tibial slope, surgeons should make all efforts to perform parallel osteotomy relative to medial posterior tibial slope. IV.

  20. Personalized implant for high tibial opening wedge: combination of solid freeform fabrication with combustion synthesis process.

    Science.gov (United States)

    Zhim, Fouad; Ayers, Reed A; Moore, John J; Moufarrège, Richard; Yahia, L'Hocine

    2012-09-01

    In this work a new generation of bioceramic personalized implants were developed. This technique combines the processes of solid freeform fabrication (SFF) and combustion synthesis (CS) to create personalized bioceramic implants with tricalcium phosphate (TCP) and hydroxyapatite (HA). These porous bioceramics will be used to fill the tibial bone gap created by the opening wedge high tibial osteotomy (OWHTO). A freeform fabrication with three-dimensional printing (3DP) technique was used to fabricate a metallic mold with the same shape required to fill the gap in the opening wedge osteotomy. The mold was subsequently used in a CS process to fabricate the personalized ceramic implants with TCP and HA compositions. The mold geometry was designed on commercial 3D CAD software. The final personalized bioceramic implant was produced using a CS process. This technique was chosen because it exploits the exothermic reaction between P₂O₅ and CaO. Also, chemical composition and distribution of pores in the implant could be controlled. To determine the chemical composition, the microstructure, and the mechanical properties of the implant, cylindrical shapes were also fabricated using different fabrication parameters. Chemical composition was performed by X-ray diffraction. Pore size and pore interconnectivity was measured and analyzed using an electronic microscope system. Mechanical properties were determined by a mechanical testing system. The porous TCP and HA obtained have an open porous structure with an average 400 µm channel size. The mechanical behavior shows great stiffness and higher load to failure for both ceramics. Finally, this personalized ceramic implant facilitated the regeneration of new bone in the gap created by OWHTO and provides additional strength to allow accelerated rehabilitation.

  1. 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.

  2. Climate stabilization wedges in action: a systems approach to energy sustainability for Hawaii Island.

    Science.gov (United States)

    Johnson, Jeremiah; Chertow, Marian

    2009-04-01

    Pacala and Socolow developed a framework to stabilize global greenhouse gas levels for the next fifty years using wedges of constant size representing an increasing use of existing technologies and approaches for energy efficiency, carbon free generation, renewables, and carbon storage. The research presented here applies their approach to Hawaii Island, with modifications to support local scale analysis and employing a "bottom-up" methodology that allows for wedges of various sizes. A discretely bounded spatial unit offers a testing ground for a holistic approach to improving the energy sector with the identification of local options and limitations to the implementation of a comprehensive energy strategy. Nearly 80% of total primary energy demand across all sectors for Hawaii Island is currently met using petroleum-based fuels.The Sustainable Energy Plan scenario included here presents an internally consistent set of recommendations bounded by local constraints in areas such as transportation efficiency, centralized renewable generation (e.g., geothermal, wind), reduction in transmission losses, and improved building efficiency. This scenario shows thatthe demand for primary energy in 2030 could be reduced by 23% through efficiency measures while 46% could be met by renewable generation, resulting in only 31% of the projected demand being met by fossil fuels. In 2030, the annual releases of greenhouse gases would be 3.2 Mt CO2-eq/year under the Baseline scenario, while the Sustainable Energy Plan would reduce this to 1.2 Mt CO2-eq/year--an annual emissions rate 40% below 2006 levels and 10% below 1990 levels. The total for greenhouse gas emissions during the 24-year study period (2007 to 2030) is 59.9 Mt CO2-eq under the Baseline scenario and 32.5 Mt CO2-eq under the Sustainable Energy Plan scenario. Numerous combinations of efficiency and renewable energy options can be employed in a manner that stabilizes the greenhouse gas emissions of Hawaii Island.

  3. 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.

  4. Monte Carlo simulation of the Varian Clinac 600C accelerator dynamic and physical wedges

    Energy Technology Data Exchange (ETDEWEB)

    Soares, S [Universidade da Beira Interior, Av. Marques d' Avila e Bolama, Covilha 6201-001 (Portugal); Chaves, A [Instituto Portugues de Oncologia Doutor Francisco Gentil (IPO), Av. Bissaya Barreto, Coimbra 3000-075 (Portugal); Peralta, L [Laboratorio de Instrumentacao e Fisica Experimental de PartIculas (LIP), Av. Elias Garcia no14 1o, Lisbon 1000-149 (Portugal); Lopes, Mc [Faculdade de Ciencias da Universidade de Lisboa, Campo Grande EdifIcio C5, Lisbon 1149-016 (Portugal)

    2007-06-15

    The present paper describes the study done on the dosimetric characteristics of the Varian Clinac 600C dynamic wedges (DW) and their comparison with the physical wedges (PW) in terms of the differences affecting the dose distributions, beam spectra, energy fluence and angular distributions. The geometry of the 4 MV photon beam and the dose distributions in a water phantom were simulated with GEANT3 and DPM Monte Carlo code systems. The DW was modelled through the constant movement of the upper jaws. The depth dose distributions and lateral profiles for the DW, PW and open fields were measured and compared with the Monte Carlo simulations and the global agreement was found to be within 3%. It was also found that the effects of a DW on beam spectral and angular distributions are much less significant than those produced by a PW. For example, in our study we found out that the 45{sup 0}PW, when compared with the corresponding open field, can introduce a 30% increase in the mean photon energy due to the beam hardening effect and that it can also introduce a 4.5% dose reduction in the build-up region because of the reduction of the contaminated electrons by the PW. For the DW neither this mean-energy increase nor such dose reduction was found. The PW, when compared to the DW, significantly alters the photon-beam spectrum and these dosimetric differences are significant and further investigation must be performed to quantify the impact in clinical use of these beams.

  5. 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).

  6. Sandbox modeling of evolving thrust wedges with different preexisting topographic relief: Implications for the Longmen Shan thrust belt, eastern Tibet

    Science.gov (United States)

    Sun, Chuang; Jia, Dong; Yin, Hongwei; Chen, Zhuxin; Li, Zhigang; Shen, Li; Wei, Dongtao; Li, Yiquan; Yan, Bin; Wang, Maomao; Fang, Shaozhi; Cui, Jian

    2016-06-01

    To understand the effects of substantial topographic relief on deformation localization in the seismically active mountains, like the Longmen Shan thrust belt in the eastern Tibet, sandbox experiments were performed based on the framework of the critical taper theory. First, a reference experiment revealed that the critical taper angle was 12° for our experimental materials. Subsequently, different proto wedges (subcritical (6° in taper angle), critical (12°), and supercritical (20°)) were introduced to cover the range of natural topographic relief, and we used two setups: setup A considered only across-strike topographic relief, whereas setup B investigated along-strike segmentation of topography, consist of two adjacent proto wedges. In all experiments, thrust wedges grew by in-sequence accretion of thrust sheets. Setup A revealed an alternating mode of slip partitioning on the accreted thrusts, with large-displacement thrust and small-displacement thrust developing in turn. And contrasting wedge evolutions occurred according to whether the proto wedge was subcritical or critical-supercritical. In setup B, the differential deformation along the strike produced transverse structures such as tear fault and lateral ramp during frontal accretion. The observed tear fault and its associated thrust system resemble the seismogenic fault system of the 2008 Mw7.9 Wenchuan earthquake. Our experimental results could also explain first-order deformation features observed in the Longmen Shan. Consequently, we conclude that topographic features, including topographic relief across the range and along-strike segmentation of topography, contribute significantly to the kinematics and deformation localization in such active mountains.

  7. Role of Neogene Exhumation and Sedimentation on Critical-Wedge Kinematics in the Zagros Orogenic Belt, Northeastern Iraq, Kurdistan

    Science.gov (United States)

    Koshnaw, R. I.; Horton, B. K.; Stockli, D. F.; Barber, D. E.; Tamar-Agha, M. Y.; Kendall, J. J.

    2014-12-01

    The Zagros orogenic belt and foreland basin formed during the Cenozoic Arabia-Eurasia collision, but the precise histories of shortening and sediment accumulation remain ambiguous, especially at the NW extent of the fold-thrust belt in Iraqi Kurdistan. This region is characterized by well-preserved successions of Cenozoic clastic foreland-basin fill and deformed Paleozoic-Mesozoic hinterland bedrock. The study area provides an excellent opportunity to investigate the linkage between orogenic wedge behavior and surface processes of erosion and deposition. The aim of this research is to test whether the Zagros orogenic wedge advanced steadily under critical to supercritical wedge conditions involving in-sequence thrusting with minimal erosion or propagated intermittently under subcritical condition involving out-of-sequence deformation with intense erosion. These endmember modes of mountain building can be assessed by integrating geo/thermochronologic and basin analyses techniques, including apatite (U-Th)/He thermochronology, detrital zircon U-Pb geochronology, stratigraphic synthesis, and seismic interpretations. Preliminary apatite (U-Th)/He data indicate activation of the Main Zagros Fault (MZF) at ~10 Ma with frontal thrusts initiating at ~8 Ma. However, thermochronometric results from the intervening Mountain Front Flexure (MFF), located between the MZF and the frontal thrusts, suggest rapid exhumation at ~6 Ma. These results suggest that the MFF, represented by the thrust-cored Qaradagh anticline, represents a major episode of out-of-sequence deformation. Detrital zircon U-Pb analyses from the Neogene foreland-basin deposits show continuous sediment derivation from sources to the NNE in Iraq and western Iran, suggesting that out-of-sequence thrusting did not significantly alter sedimentary provenance. Rather, intense hinterland erosion and recycling of older foreland-basin fill dominated sediment delivery to the basin. The irregular distribution of

  8. 3D Stress-Strain Analysis of a Failed Limestone Wedge Influenced by an Intact Rock Bridge

    Science.gov (United States)

    Paronuzzi, Paolo; Bolla, Alberto; Rigo, Elia

    2016-08-01

    This paper presents a back-analysis of a rock wedge failure (volume = 25-30 m3) that involved a limestone scarp in the Rosandra valley (Trieste karst, NE Italy). Thanks to the mechanical survey of the detachment surface, a single rock bridge having a size of about 15 cm × 30 cm has been ascertained. A 3D stress-strain analysis has been performed to examine the influence of the rock bridge on the block stability (initial unweathered condition: strength reduction factor SRF equal to 1.14). The shear strength provided by the basal and lateral joints represents the main contributing factor for the wedge stability (about 60-75 % of the whole resisting system). However, the equilibrium of the wedge was temporarily attained thanks to the strength contribution provided by the rock bridge (25-40 %) until the acting forces locally exceeded the resisting forces, thus determining the bridge rupture and, as a consequence, the wedge collapse. The mean shear stress acting on the rock bridge at failure ranges from about 3.5 to 5 MPa. Calculated block displacements up to failure vary from 0.6 to 1.5 mm, depending on the different elastic modulus assumed for the wedge ( E = 30, 10, and 4 GPa). Pre-collapse block displacements increase as a result of the shear strength decrease that was initially caused by the weathering of the delimiting rock joints and, further, by the progressive failure of the rock bridge. The cohesion at failure of the rock bridge ranges from 2.1 to 2.6 MPa (friction angle of intact rock φ = 40°).

  9. Recent movements along the Main Boundary Thrust of the Himalayas: Normal faulting in an over-critical thrust wedge?

    Science.gov (United States)

    Mugnier, Jean-Louis; Huyghe, Pascale; Chalaron, Edouard; Mascle, Georges

    1994-11-01

    The Main Boundary Thrust (MBT) is one of the major Himalayan thrusts occurring during the Cainozoic, and it is presently incorporated within the Himalayan thrust wedge (Lesser and Outer Himalayas) displaced above the Indian lithosphere. Nonetheless the MBT shows recent normal displacement along most of its length. We suggest that the orientation of the major principal stress within the Himalayan thrust wedge deviates significantly from the horizontal and when this deviation exceeds the dip of the vectors normal to back-tilted thrusts, the normal component of displacement may act along these faults. Steep north-dipping segments of the MBT therefore show a normal component of displacement if a geometrical definition is used, but they are faults in a compressional regime where the major principal stress axis has deviated from the horizontal. Micro-structural data recorded along the Surkhet-Ghorahi segment of the MBT are consistent with a strong deviation of the state of stress. The presence of such peculiar normal faulting along the MBT is used to calibrate the mechanical characteristics of the belt considered as a Coulomb wedge. The following characteristics are suggested: (a) very poor strength contrast between basal decollement and rocks in the wedge body, (b) a high pore fluid pressure ratio (probably close to 0.8-0.9) and a higher fluid pressure ratio (close to 1.0) along the active normal faults if a high internal friction angle (close to the Byerlee value) is considered. The strong deviation in principal stress direction may have recently increased, due to a taper of the Himalayan wedge exceeding the stability boundary and may be controlled by erosion and isostatic uplift rebound of the Himalayan range.

  10. Seafloor morphology in the different domains of the Calabrian Arc subduction complex - Ionian Sea

    Science.gov (United States)

    Riminucci, F.; Polonia, A.; Torelli, L.; Mussoni, P.

    2010-05-01

    The Calabrian Arc (CA) is a subduction system that develops along the African-Eurasian plate boundary in the Ionian Sea and connects the E-W trending Sicilian Maghrebian belt with the NW-SE trending Southern Apennines. The first systematic geophysical investigation in the offshore region of the CA was conducted during the 70's by the Institute of Marine Geology (now ISMAR) with the R/V 'Bannock' [1]. In the last 30 years, further geophysical data (high penetration multichannel seismics, CHIRP and multibeam data) has been acquired in the offshore of the CA, down to the Ionian Abyssal Plain. The integrated interpretation of the existing geophysical data [2] has outlined the regional architecture of the subduction complex, the main tectonic features absorbing plate motion and variation of seafloor morphology in the different structural domains. Pre-stack depth migrated seismic profiles has revealed that the accretionary complex is constituted by two distinct wedges whose geometry, structural style and seafloor morphology widely vary. The outermost accretionary wedge has been emplaced in post-messinian times. It is a salt-bearing complex as pointed out by the internal structure of the wedge (acoustically transparent assemblage), very low taper angle and high seismic velocities. The seafloor shows a rough morphology, short wavelength folds and depressions superimposed on a rather constant gentle regional slope. Landward of the outer wedge, the evaporites are no longer present and the transition to the clastic rock assemblage is reflected in a different structural architecture, which shows steeper slopes and a succession of topographic scarps separated by sedimentary basins and mid slope terraces. The topographic scarps are controlled in depth by a series of high angle landward dipping reflectors, that we interpreted as out of sequence thrust faults absorbing shortening at the rear of the wedge. Landward of the inner wedge a mid slope terrace develops (inner plateau

  11. 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.

  12. Effects of medially wedged foot orthoses on knee and hip joint running mechanics in females with and without patellofemoral pain syndrome.

    Science.gov (United States)

    Boldt, Andrew R; Willson, John D; Barrios, Joaquin A; Kernozek, Thomas W

    2013-02-01

    We examined the effects of medially wedged foot orthoses on knee and hip joint mechanics during running in females with and without patellofemoral pain syndrome (PFPS). We also tested if these effects depend on standing calcaneal eversion angle. Twenty female runners with and without PFPS participated. Knee and hip joint transverse and frontal plane peak angle, excursion, and peak internal knee and hip abduction moment were calculated while running with and without a 6° full-length medially wedged foot orthoses. Separate 3-factor mixed ANOVAs (group [PFPS, control] x condition [medial wedge, no medial wedge] x standing calcaneal angle [everted, neutral, inverted]) were used to test the effect of medially wedged orthoses on each dependent variable. Knee abduction moment increased 3% (P = .03) and hip adduction excursion decreased 0.6° (P < .01) using medially wedged foot orthoses. No significant group x condition or calcaneal angle x condition effects were observed. The addition of medially wedged foot orthoses to standardized running shoes had minimal effect on knee and hip joint mechanics during running thought to be associated with the etiology or exacerbation of PFPS symptoms. These effects did not appear to depend on injury status or standing calcaneal posture.

  13. Translation domains in multiferroics

    OpenAIRE

    Meier, D; Leo, N; Jungk, T.; Soergel, E.; Becker, P.; Bohaty, L.; Fiebig, M.

    2010-01-01

    Translation domains differing in the phase but not in the orientation of the corresponding order parameter are resolved in two types of multiferroics. Hexagonal (h-) YMnO$_3$ is a split-order-parameter multiferroic in which commensurate ferroelectric translation domains are resolved by piezoresponse force microscopy whereas MnWO$_4$ is a joint-order-parameter multiferroic in which incommensurate magnetic translation domains are observed by optical second harmonic generation. The pronounced ma...

  14. Frustratingly Easy Domain Adaptation

    CERN Document Server

    Daumé, Hal

    2009-01-01

    We describe an approach to domain adaptation that is appropriate exactly in the case when one has enough ``target'' data to do slightly better than just using only ``source'' data. Our approach is incredibly simple, easy to implement as a preprocessing step (10 lines of Perl!) and outperforms state-of-the-art approaches on a range of datasets. Moreover, it is trivially extended to a multi-domain adaptation problem, where one has data from a variety of different domains.

  15. Staggered domain wall fermions

    CERN Document Server

    Hoelbling, Christian

    2016-01-01

    We construct domain wall fermions with a staggered kernel and investigate their spectral and chiral properties numerically in the Schwinger model. In some relevant cases we see an improvement of chirality by more than an order of magnitude as compared to usual domain wall fermions. Moreover, we present first results for four-dimensional quantum chromodynamics, where we also observe significant reductions of chiral symmetry violations for staggered domain wall fermions.

  16. Collinear spin-density-wave ordering in Fe/Cr multilayers and wedges

    Energy Technology Data Exchange (ETDEWEB)

    Fishman, R.S. [Solid State Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6032 (United States); Shi, Z. [Read-Rite Corporation, R D Division, 345 Los Coches Street, Milpitas, California 95035 (United States)

    1999-06-01

    Several recent experiments have detected a spin-density wave (SDW) within the Cr spacer of Fe/Cr multilayers and wedges. We use two simple models to predict the behavior of a collinear SDW within an Fe/Cr/Fe trilayer. Both models combine assumed boundary conditions at the Fe-Cr interfaces with the free energy of the Cr spacer. Depending on the temperature and the number {ital N} of Cr monolayers, the SDW may be either commensurate ({ital C}) or incommensurate ({ital I}) with the bcc Cr lattice. Model I assumes that the Fe-Cr interface is perfect and that the Fe-Cr interaction is antiferromagnetic. Consequently, the {ital I} SDW antinodes lie near the Fe-Cr interfaces. With increasing temperature, the Cr spacer undergoes a series of transitions between {ital I} SDW phases with different numbers {ital n} of nodes. If the {ital I} SDW has n=m nodes at T=0, then {ital n} increases by one at each phase transition from {ital m} to m{minus}1 to m{minus}2 up to the {ital C} phase with n=0 above T{sub IC}(N). For a fixed temperature, the magnetic coupling across the Cr spacer undergoes a phase slip whenever {ital n} changes by one. In the limit N{r_arrow}{infinity}, T{sub IC}(N) is independent of the Fe-Cr coupling strength. We find that T{sub IC}({infinity}) is always larger than the bulk N{acute e}el transition temperature and increases with the strain on the Cr spacer. These results explain the very high IC transition temperature of about 600 K extrapolated from measurements on Fe/Cr/Fe wedges. Model II assumes that the {ital I} SDW nodes lie precisely at the Fe-Cr interfaces. This condition may be enforced by the interfacial roughness of sputtered Fe/Cr multilayers. As a result, the {ital C} phase is never stable and the transition temperature T{sub N}(N) takes on a seesaw pattern as n{ge}2 increases with thickness. In agreement with measurements on both sputtered and epitaxially grown multilayers, model II predicts the {ital I} phase to be unstable above the bulk N

  17. Deformation processes in orogenic wedges: New methods and application to Northwestern Washington State

    Science.gov (United States)

    Thissen, Christopher J.

    Permanent deformation records aspects of how material moves through a tectonic environment. The methods required to measure deformation vary based on rock type, deformation process, and the geological question of interest. In this thesis we develop two new methods for measuring permanent deformation in rocks. The first method uses the autocorrelation function to measure the anisotropy present in two-dimensional photomicrographs and three-dimensional X-ray tomograms of rocks. The method returns very precise estimates for the deformation parameters and works best for materials where the deformation is recorded as a shape change of distinct fabric elements, such as grains. Our method also includes error estimates. Image analysis techniques can focus the method on specific fabric elements, such as quartz grains. The second method develops a statistical technique for measuring the symmetry in a distribution of crystal orientations, called a lattice-preferred orientation (LPO). We show that in many cases the symmetry of the LPO directly constrains the symmetry of the deformation, such axial flattening vs. pure shear vs. simple shear. In addition to quantifying the symmetry, the method uses the full crystal orientation to estimate symmetry rather than pole figures. Pole figure symmetry can often be misleading. This method works best for crystal orientations measured in samples deformed by dislocation creep, but otherwise can be used on any mineral without requiring information about slip systems. In Chapter 4 we show how deformation measurements can be used to inform regional tectonic and orogenic models in the Pacific Northwestern United States. A suite of measurements from the Olympic Mountains shows that uplift and deformation of the range is consistent with an orogenic wedge model driven by subduction of the Juan de Fuca plate, and not northward forearc migration of the Oregon block. The deformation measurements also show that deformation within the Olympic Mountains

  18. Pragmatic circuits frequency domain

    CERN Document Server

    Eccles, William

    2006-01-01

    Pragmatic Circuits: Frequency Domain goes through the Laplace transform to get from the time domain to topics that include the s-plane, Bode diagrams, and the sinusoidal steady state. This second of three volumes ends with a-c power, which, although it is just a special case of the sinusoidal steady state, is an important topic with unique techniques and terminology. Pragmatic Circuits: Frequency Domain is focused on the frequency domain. In other words, time will no longer be the independent variable in our analysis. The two other volumes in the Pragmatic Circuits series include titles on DC

  19. Deformation in the mantle wedge associated with Laramide flat-slab subduction

    Science.gov (United States)

    Behr, Whitney M.; Smith, Douglas

    2016-07-01

    Laramide crustal deformation in the Rocky Mountains of the west-central United States is often considered to relate to a narrow segment of shallow subduction of the Farallon slab, but there is no consensus as to how deformation along the slab-mantle lithosphere interface was accommodated. Here we investigate deformation in mantle rocks associated with hydration and shear above the flat-slab at its contact with the base of the North American plate. The rocks we focus on are deformed, hydrated, ultramafic inclusions hosted within diatremes of the Navajo Volcanic Field in the central Colorado Plateau that erupted during the waning stages of the Laramide orogeny. We document a range of deformation textures, including granular peridotites, porphyroclastic peridotites, mylonites, and cataclasites, which we interpret to reflect different proximities to a slab-mantle-interface shear zone. Mineral assemblages and chemistries constrain deformation to hydrous conditions in the temperature range ˜550-750°C. Despite the presence of hydrous phyllosilicates in modal percentages of up to 30%, deformation was dominated by dislocation creep in olivine. The mylonites exhibit an uncommon lattice preferred orientation (LPO) in olivine, known as B-type LPO in which the a-axes are aligned perpendicular to the flow direction. The low temperature, hydrated setting in which these fabrics formed is consistent with laboratory experiments that indicate B-type LPOs form under conditions of high stress and high water contents; furthermore, the mantle wedge context of these LPOs is consistent with observations of trench-parallel anisotropy in the mantle wedge above many modern subduction zones. Differential stress magnitudes in the mylonitic rocks estimated using paleopiezometry range from 290 to 444 MPa, and calculated effective viscosities using a wet olivine flow law are on the order of 1019-1023 Pa s. The high stress magnitudes, high effective viscosities, and high strains recorded in these

  20. Mud volcano venting induced gas hydrate formation at the upper slope accretionary wedge, offshore SW Taiwan

    Science.gov (United States)

    Lin, Saulwood; Tseng, Yi-Ting; Cheng, Wan-Yen; Chou, Cheng-Tien; Chen, NeiChen; Hsieh, I.-Chih

    2016-04-01

    TsanYao Mud Volcano (TYMV) is the largest mud volcano cone in the Hengchun Mud Volcano Group (HCMVG), located at the upper slope of the accrretionary wedge, southwest of Taiwan. The region is under active tectonic activity with the Philippine Plate, moving northwestward at a rate of ~8 cm/year. This region also receives huge quantity of suspended particle load of ~100 mT/year at present time from adjacent small rivers of the Island of Taiwan. Large loads of suspended sediments influx become a major source of organic carbon and later gas and other hydrocarbon. Gas and fluid in the mud volcano are actively venting from deep to the sea floor on the upper slope of the accretionary wedge. In order to understand venting on the HCMVG, echo sounder, towcam and coring were carried out. Pore water sulfate, chloride, potassium, calcium, stable isotope O-18, gas compositions, dissolved sulfide were analysed. The HCMVG consists of 12 volcano cones of different sizes. Large quantity of gas and fluid are venting directly from deep to the TYMV structure high, as well as 50+ other vents as appeared as flares on the echo sounder. Some flares are reaching to the atmosphere and likely a source of green house gases to the atmosphere. Venting fluids include gas bubbles, suspended particle, mud, and breccia. Breccia size could reach more than 12 cm in diameter. Circular bands in different color appeared around the cone may represent stages of vent eruptions. Compositions of vent gas include methane, ethane and propane. High proportions of ethane and propane in the vent gas demonstrated that source of gas are thermogenic in origin. Patchy authigenic carbonate, bacterial mats, bivalves, tube worms and other chemosynthesis organisms were supported by venting gas AOM process near the sea floor. Pore water chloride concentrations show distinct variation pattern from center cone to the side of the volcano, with low in the center and high away from the cone. Pore water with higher than seawater