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Showing papers on "Transverse plane published in 1987"


Journal ArticleDOI
01 Mar 1987-Spine
TL;DR: Pedicles were widest at L5 and narrowest at T5 in the transverse plane and in the sagittal plane, and the depth to the anterior cortex was significantly longer along the pedicle axis than along a line parallel to the midline of the vertebral body.
Abstract: A total of 2,905 pedicle measurements were made from T1-L5. Measurements were made from spinal computerized tomography (CT) scan examinations and individual vertebral specimen roentgenograms. Parameters considered were the pedicle isthmus width in the transverse and sagittal planes, pedicle angles in the transverse and sagittal planes, and the depth to the anterior cortex in a line parallel to the midline of the vertebral body and along the pedicle axis. There was no significant difference between data obtained from CT scans and specimen roentgenograms. Pedicles were widest at L5 and narrowest at T5 in the transverse plane. The widest pedicles in the sagittal plane were seen at T11, the narrowest at T1. Due to the oval shape of the pedicle, the sagittal plane width was generally larger than the transverse plane width. The largest pedicle angle in the transverse plane was at L5. The posterolateral to anterolateral pedicle axis orientation in the transverse plane, seen at other levels throughout the thoracolumbar spine, reversed at T12. In the sagittal plane, the pedicles angled caudally at L5 and cephaladly from L3-T1. The depth to the anterior cortex was significantly longer along the pedicle axis than along a line parallel to the midline of the vertebral body at all levels with the exception of T12 and T11.

491 citations


Journal ArticleDOI
Abstract: Summary. We report herein on a finite element algorithm for 2-D magnetotelluric modelling which solves directly for secondary variations in the field parallel to strike, plus the subsequent vertical and transverse auxiliary fields, for both transverse electric and transverse magnetic modes. The governing Helmholtz equations for the secondary fields along strike are the same as those for total field algorithms with the addition of source terms involving the primary fields and the conductivity difference between the body and the host. Our approach has overcome a difficulty with numerical accuracy at low frequencies observed in total field solutions with 32-bit arithmetic far the transverse magnetic mode especially, but also for the transverse electric mode. Matrix ill-conditioning, which affects total field solutions, increases with the number of element rows with the square of the maximum element aspect ratio and with the inverse of frequency. In the secondary formulation, the field along strike and the auxiliary fields do not need to be extracted in the face of an approximately computed primary field which increasingly dominates the total field solution towards low frequencies. In addition to low-frequency stability, the absolute accuracy of our algorithm is verified by comparison with the TM and the TE mode analytic responses of a segmented overburden model.

337 citations


Journal ArticleDOI
TL;DR: In this article, large-scale organized structures in the turbulent plane wake of a circular cylinder are investigated in air up to a downstream distance of 40d at a Reynolds number of Red = 1.3 × 104; d is the cylinder diameter.
Abstract: Large-scale organized structures in the turbulent plane wake of a circular cylinder are investigated in air up to a downstream distance of 40d at a Reynolds number of Red = 1.3 × 104; d is the cylinder diameter. Velocity signals from a linear transverse rake of 8 X-wires are sampled simultaneously to calculate the instantaneous span wise vorticity. We have appropriately smoothed the temporal traces of vorticity to obtain time evolutions (including the transverse displacement, sign, strength and size distributions) of organized structures identified by vorticity contour maps. The periodicity of the initial structures is rapidly lost: dispersion in streamwise spacing, transverse displacement, strength and size of structures increases with increasing downstream distance.Particular emphasis is placed on examining alternative general schemes for educing coherent structures in natural or unexcited turbulent shear flows, especially in their fully developed states. The optimal eduction scheme employed involves centring the rake at the most probable transverse location of centres of advected structures and accepting those structures that: (i) are centred at the midpoint of the rake, (ii) have a peak value of (smoothed) vorticity of a given sign above a specified level, and (iii) have streamwise and transverse extents of the (smoothed) vorticity contours above a specified size. From successive accepted structure signatures the instants of occurrence of structure centres (i.e. smoothed vorticity peaks) are identified. Un-smoothed signals are then time-aligned with respect to these instants and ensemble averaged to educe coherent structure and incoherent turbulence characteristics. Further enhancement is achieved by iteratively improving the time-alignment by maximizing the cross-correlation of individual structure vorticity with the ensemble-averaged vorticity and by discarding structures that require excessive time shifts or that produce significantly weak peak correlation values.Following this optimal scheme, large-scale coherent structures have been educed in the fully turbulent wake. The average structure centre is found to be closer to the wake centreline than the half-width location, and the structure size does not increase in proportion to the wake width, suggesting that transverse wandering of structures (including their three-dimensionality) increases significantly with increasing downstream distance. The various flow properties associated with coherent and incoherent turbulence, and the coherent structure dynamics, in particular the role of vortex stretching (at the saddle) in turbulence production and mixing, are discussed.

225 citations


Journal ArticleDOI
TL;DR: The theory and experimental feasibility of measuring Doppler spectra in transverse geometries is presently investigated, finding that the probing of flows transverse to the axis of finite diameter beams, particularly focused beams, is feasible.
Abstract: It is an accepted fact that transverse Doppler effects of the first order in v/c are nonexistent for all physical wave phenomena, including acoustics, i.e., the Doppler effect is zero for radiation normal to the direction of motion. However, this statement assumes that the incident field is a plane wave, which is not true in general for finite aperture sources. Consequently, the probing of flows transverse to the axis of finite diameter beams, particularly focused beams, is feasible. This geometry will be advantageous in many applications where the classical orientation of the sound beam, oblique to the flow, is not possible. With this motivation in mind, the theory and experimental feasibility of measuring Doppler spectra in transverse geometries is presently investigated.

191 citations


Journal ArticleDOI
TL;DR: In this article, the alternating direction Galerkin technique was applied to the simulation of field-scale contaminant transport scenarios in two and three dimensions, and dimensionality effects were examined.
Abstract: The alternating direction Galerkin technique developed in the first paper of this series is applied to the simulation of field-scale contaminant transport scenarios in two and three dimensions, and dimensionality effects are examined. In the case of vertical-plane simulation, the dimensionality effect, which becomes noticeable at a transverse dispersivity of only 1 cm, can result in significant overestimation of plume length. In the case of vertically averaged horizontal plane simulation, the apparent length of a plume defined in terms of vertical averages will be much less than that of the equivalent plume defined in terms of peak concentrations. Only the three-dimensional simulation is capable of producing the actual concentration values that drive local processes such as chemical reactions. The cost of the three-dimensional simulations, while substantially greater than that of the two-dimensional simulations, is shown to be reasonable.

128 citations


Journal ArticleDOI
TL;DR: In this article, a large reversible degradation of the critical current of multifilamentary Nb3Sn superconductors was observed when uniaxial compressive stress is applied transverse to the conductor axis at 4 K.
Abstract: A large reversible degradation of the critical current of multifilamentary Nb3Sn superconductors has been observed when uniaxial compressive stress is applied transverse to the conductor axis at 4 K. In bronze‐process multifilamentary Nb3Sn, the onset of significant degradation occurs at about 50 MPa. In an applied field of 10 T, the magnitude of the effect is about seven times larger for transverse stress than for stress applied along the conductor axis. The transverse stress effect increases with magnetic field and is associated with a reversible degradation of the upper critical field. The intrinsic effect of transverse stress on the upper critical field is about ten times greater than for axial stress. Although axial stresses on the Nb3Sn filaments are greater than transverse stresses in most applications, the transverse stress effect will need to be considered in the internal design of large magnets because of the greater sensitivity of Nb3Sn to transverse stress. It is shown that the transverse stre...

124 citations


Journal ArticleDOI
TL;DR: In this article, a technique that quantifies the in-plane flow properties of fibrous networks is pre sented, which allows the simultaneous study of more than one in- plane flow direction.
Abstract: A technique that quantifies the in-plane flow properties of fibrous networks is pre sented. A radial flow geometry allows the simultaneous study of more than one in- plane flow direction. The shape and position of a radially advancing fluid front define directional permeabilities in the plane, which can be used to compare structurally different fibrous networks. Confirmatory studies reinforce the method of data analysis and show that the directional permeabilities are independent of driving pressure, fluid viscosity, and fiber surface wettability properties. The methodology was applied to the study of multilayer assemblies. The in-plane flow of fluids in heterogeneous multilayer constructions is governed by the high permeability layer. A transverse flow mechanism is proposed as being responsible for filling the low permeability layers and, therefore, the transverse permeability is coupled into this flow process.

119 citations


Journal ArticleDOI
James F. Doyle1
TL;DR: In this article, the contact force during the transverse impact of a plate is determined from dynamic strain-gage measurements made on the plate, and comparisons are made with finite-element predictions and measurements from a force transducer.
Abstract: The contact force during the transverse impact of a plate is determined from dynamic strain-gage measurements made on the plate. Experimental results for the impact of an aluminum plate are presented, and comparisons are made with finite-element predictions and measurements from a force transducer.

91 citations


Journal ArticleDOI
TL;DR: In this paper, two frequency and amplitude-modulated pulses are described that can accomplish a 90 and 180° plane rotation in the presence of large B, field inhomogeneities.

89 citations


Journal ArticleDOI
TL;DR: In this paper, a theoretical study of transverse self-phase modulation effects in the transmission of a laser beam through a nonlinear thin film is presented, where the occurrence of interference rings, intensification or dimming of the on-axis beam intensity, and transverse optical bistability in the presence of a feedback are systematically documented in terms of geometrical/optical parameter classifications.
Abstract: We present a theoretical study, with reference to experimental results, of transverse self-phase modulation effects in the transmission of a laser beam through a nonlinear thin film. The occurrence of interference rings, intensification or dimming of the on-axis beam intensity, and transverse optical bistability in the presence of a feedback can all be systematically documented in terms of geometrical/optical parameter classifications. These studies provide further insights and useful guides for experimental studies.

77 citations


Patent
19 Jun 1987
TL;DR: In this article, a joint profile for the longitudinal edges of profiled-edge boards is proposed for producing profiled edge boards which interlock with their longitudinal edge profiles and are preferably glued at the profile joint, for producing wooden panels, in particular glued solidwood panels.
Abstract: Described is a novel joint profile for the longitudinal edges of profiled-edge boards for producing profiled-edge boards which interlock with their longitudinal edge profiles and are preferably glued at the profile joint, for producing wooden panels, in particular glued solid-wood panels. The joint profile has two rectilinear vertical legs, parallel to one another and staggered laterally in the direction of the panel or board plane, and a rectilinear transverse leg, connecting the vertical legs to one another at their inner ends, in such a configuration and mutual arrangement that the joint profile has the overall shape of a "victory rune", the transverse leg facing the vertical leg which is offset laterally inwards. A number of important advantages are obtained with this design: the transfer of the profiled-edge boards, at first placed only in a loosely interlocking position, into the closing position and the pressing for the gluing can be effected by applying pressure both transversely to the panel plane and parallel to the panel plane, automatic joint closing and locking of the joints in the closed state being guaranteed. In both cases, whether external pressure is applied transversely or longitudinally, sufficient force components acting transversely to the leg surface are obtained in the process at all joint-profile legs for pressing the glue layer into the ... Original abstract incomplete.

Journal ArticleDOI
TL;DR: In this article, a simple and inexpensive method is proposed to measure time-averaged concentrations under waves, which is defined by sucking samples in a direction normal to the ambient water motion at an intake velocity which exceeds the ambient flow velocity more than three times.

Patent
06 Oct 1987
TL;DR: In this article, a double-layer or multi-layer fabric of interwoven longitudinal and transverse threads is used for sheet forming in a paper making machine, where the transverse thread is disposed below the plane formed by the transversal threads of the paper supporting side.
Abstract: The fabric for the sheet forming section of a paper making machine includes a double-layer or multi-layer fabric of interwoven longitudinal and transverse threads and additional transverse threads floating on the paper supporting side. The additional transverse threads are interwoven in a plane disposed below the plane formed by the transverse threads of the paper supporting side. The additional transverse threads preferably have a smaller diameter than the ordinary transverse threads.


Journal ArticleDOI
TL;DR: It is suggested that cross-polarization measurement using a null detector can serve as a new method for accurate determination of the center of Gaussian laser beams.
Abstract: Polarization properties of Gaussian laser beams are analyzed in a manner consistent with the Maxwell equations, and expressions are developed for all components of the electric and magnetic field vectors in the beam. It is shown that the transverse nature of the free electromagnetic field demands a nonzero transverse cross-polarization component in addition to the well-known component of the field vectors along the beam axis. The strength of these components in relation to the strength of the principal polarization component is established. It is further shown that the integrated strengths of these components over a transverse plane are invariants of the propagation process. It is suggested that cross-polarization measurement using a null detector can serve as a new method for accurate determination of the center of Gaussian laser beams.

Journal ArticleDOI
TL;DR: In this article, a spectral domain analysis based method for solving the electromagnetic wave scattering by an infinite plane metallic grating is presented, which discretizes the spectral formulation in terms of the sampling theorem.
Abstract: A new method, based on the spectral domain analysis, is presented for solving the electromagnetic wave scattering by an infinite plane metallic grating. The key point of the present method is discretization of spectral formulation in terms of the sampling theorem. Two different polarizations, transverse magnetic (TM) and transverse electric (TE) excitations, are considered here. Accuracy of the present method is examined numerically by comparison with the rigorous Wiener-Hopf solutions which are applicable only to a special case. Since the end effect of a conducting strip is taken into account analytically, final results show enough convergence to evaluate the near fields as well as the far fields with small matrix calculations. Some numerical examples are shown mainly for surface current distributions to make clear the differences between the two different polarizations.

Journal ArticleDOI
Young-Pil Park1
TL;DR: In this paper, a finite element model of the beam transverse motion in the plane is formulated through the extended Hamilton's principle, and the dynamic stability of the model is studied with respect to (i) the location of the follower force direction control sensor, (ii) the sensor gain, (iii) the magnitudes of the rotary inertia and shear deformation parameters of a beam, and (iv) the magnitude of the constant follower force.

Journal ArticleDOI
TL;DR: In this article, an inverse scattering method was proposed to reconstruct simultaneously the permittivity profile and the conductivity profile of one-dimensional inhomogeneons medium which makes use of the transverse electric (TE) wave and/or transverse magnetic (TM) wave.
Abstract: An inverse scattering method to reconstruct simultaneously the permittivity profile and the conductivity profile of one-dimensional inhomogeneons medium which makes use of the transverse electric (TE) wave and/or transverse magnetic (TM) wave, is proposed. The medium is illuminated by the TE and/or TM plane wave at oblique incidence, and the data are taken as the reflection coefficients for a set of discrete frequencies and/or a finite number of incident angles. Furthermore, the reflection coefficient data contain the Gaussian noise. The nonlinear integral equation relating the unknown constitutive parameter of the medium to the reflection coefficient for TE wave and/or TM wave is solved by the Newton iteration method. The inverse operator in the Newton method is determined by the regularization method. It is demonstrated in terms of the numerical examples that this method utilizing both polarizations and the incident angle of the incident plane wave is very effective even if the reflection coefficient contains the practical measurement error, or the phase of the reflection coefficient is unknown. Moreover, the relationships between the errors of reconstructed profile and the measured reflection coefficient are also discussed.

Patent
18 Sep 1987
TL;DR: In this paper, an array of conveyor rollers in a glass sheet bending and tempering section is adapted to be curved around an axis of curvature transverse to the traveling direction in a manner that, beginning from a horizontal plane, the plane of a roller line curves with a continuously diminishing radius of curvatures until the final radius is reached.
Abstract: The invention relates to a method of bending a glass sheet to be tempered as well as to a glass sheets bending and tempering apparatus. An array of conveyor rollers in a glass sheets bending and tempering section is adapted to be curved around an axis of curvature transverse to the traveling direction in a manner that, beginning from a horizontal plane, the plane of a roller line curves with a continuously diminishing radius of curvature until the final radius of curvature is reached. During the curving process, the tangent of the mid-portion of a curved conveyor section is maintained substantially in a horizontal plane. Thus, each point in a glass sheet curves substantially at the same rate over the entire glass sheet area and, hence, local rapid deformations do not occur. During the curving process, a glass sheet is maintained in motion by means of the rollers of a curved roller conveyor.

Journal ArticleDOI
TL;DR: In this article, a set of coupled integral equations based on a plane wave representation of the fields in a simply connected and anisotropic medium has been derived in order to handle the problem of scattering by a homogeneous aisotropic cylinder for an obliquely incident plane wave of arbitrary linear polarization.
Abstract: A set of two coupled integral equations based on a plane wave representation Of the fields in a simply connected and anisotropic medium has been derived in order to handle the problem of scattering by a homogeneous anisotropic cylinder for an obliquely incident plane wave of arbitrary linear polarization. The unknowns are scalar, the range of integration is finite, and the kernels are not singular. Numerical results are presented and discussed in detail. The gyrotropic type case is emphasized, and it is found that as in the isotropic case, the depolarization is the same for transverse electric (TE) and transverse magnetic (TM) incident waves.

Journal ArticleDOI
TL;DR: In this article, the theory of characteristic modes for apertures is applied to solve the problem of infinite long slot in a perfectly conducting plane in an unbounded medium illuminated by a uniform transverse electric (TE) plane wave.
Abstract: Consider an infinitely long slot in a perfectly conducting plane in an unbounded medium illuminated by a uniform transverse electric (TE) (to the slot axis) plane wave. The theory of characteristic modes for apertures is applied to solve the problem. For a narrow slot, analytic expressions for the first two characteristic currents and the equivalent magnetic current are given. As computed by the method of moments, numerical results for the characteristic currents and fields, the equivalent magnetic current, and the transmitted field pattern are presented for the slot whose width is one wavelength.

Journal ArticleDOI
TL;DR: Regional transverse stiffness appears to allow quantitative estimation of regional in-plane stresses and can distinguish between actively generated and passively applied stress.
Abstract: Determination of regional ventricular wall stress would allow quantification of both regional contractile state and its interplay with global function. Current methods for quantifying regional stress include mathematical modelling and measurements with strain gauges. Both methods are difficult to validate. We hypothesized that transverse stiffness (i.e., the ratio of indentation stress to strain as the ventricular wall is indented in the direction perpendicular to the wall) would be proportional to the stresses in the plane of the wall and could be used to estimate the latter. To test this hypothesis, 6 arterially perfused canine ventricular septa were mounted in an apparatus that could exert biaxial load in the plane of the wall. A servo system maintained the central third of the septa isometric during active contractions while the septa were paced at 30-60 pulses/min. In the center of the isometric region, a probe of 7 mm diameter indented the septa while the transverse indentation stress and strain were measured. For values of peak systolic in-plane stress from 0.56 to 2.6 g/mm2, the transverse stiffness varied from 1.2 to 11.7 g/mm2 and was linearly related to the in-plane wall stress in each septum (p less than 0.001, ANOVA). After cardioplegia, the transverse stiffness also correlated with passively applied wall stress for each dog (p less than 0.001). The slopes of the individual relations between transverse stiffness and wall stress from active contractions were similar to those from passively applied stress (mean +/- SEM; 1.82 +/- 0.36 versus 1.45 +/- 0.31, NS).(ABSTRACT TRUNCATED AT 250 WORDS)


Journal ArticleDOI
TL;DR: In this paper, the transverse vibrations of an axially moving (travelling in its own plane) membrane submerged in ideal fluid are analyzed using the FEM, which differs from the equations of the common coupled problem in that there appear two additional inertia terms due to the convective acceleration.
Abstract: Transverse vibrations of an axially moving (travelling in its own plane) membrane submerged in ideal fluid are analysed using the FEM. The discrete equations differ from the equations of the common coupled problem in that there appear two additional inertia terms due to the convective acceleration. The effect of the density of the element mesh, the effect of the truncation distance and the effect of various lumping techniques on the accuracy of the results are studied. The FEM-results are compared with available analytical and experimental results. The agreement seems to be rather good.

Proceedings ArticleDOI
24 Mar 1987
TL;DR: The response of circular air jets to combined streamwise and transverse acoustic excitation is described in this article, where the jet evolution and structure are documented by flow visualization when the ratio of axial to transverse excitation frequencies is two, the jet ‘bifurcates into two distinct jets
Abstract: The response of circular air jets to combined streamwise and transverse acoustic excitation is described The jet evolution and structure are documented by flow visualization When the ratio of axial to transverse excitation frequencies is two, the jet ‘bifurcates” into two distinct jets The spreading angle increases dramatically with excitation amplitude

Patent
07 Dec 1987
TL;DR: In this article, the authors proposed a method and apparatus for reducing the amount of an external fluid which travels through an opening into an enclosed area, by causing a fluid to flow, in laminar form, in proximity to or directly across an opening, a surface or an area plane to be protected.
Abstract: A method and apparatus for reducing the amount of an external fluid which travels through an opening into an enclosed area. Also, a method and apparatus for protecting a surface area or plane from contact with or intermixing with an external fluid. The method, in general, comprises causing a fluid to flow, in laminar form, in proximity to or directly across an opening, a surface or an area plane to be protected. The depth or thickness of the flowing laminar fluid layer at its source of origin is at least about 0.05 times the distance across the opening, surface area or plane to be protected, in the principal direction of flow of the fluid at its source of origin. The width of fluid flow at its source of origin and transverse the direction of fluid flow is at least about as great as the maximum width of the opening, surface or area plane to be protected, transverse the direction of fluid flow. The Force Number of the fluid must range between about 0.05 and about 50; the preferred range for the Force Number is from about 0.1 to about 10.

Journal ArticleDOI
TL;DR: In this article, the design and basic operating characteristics of a co-axial radio-frequency discharge carbon dioxide laser which employs a multipass Herriott cell folding system within a linear resonator were reported.
Abstract: We report the design and basic operating characteristics of a co‐axial radio‐frequency discharge carbon dioxide laser which employs a multipass Herriott cell folding system within a linear resonator. A continuous wave laser power output of 65 W was obtained from a device 35 cm in length in a high‐quality TEM00 mode without gas flow. The characteristics of transverse rf discharges and the image rotation properties of such resonators indicate that this approach may be scalable to provide much higher laser powers with excellent transverse mode properties.

Journal ArticleDOI
TL;DR: In this paper, the problem of transverse impact on an elastic plate for which the effect of deformation due to transverse shear cannot be neglected, e.g., a thick plate or one reinforced with aligned fibres in its plane, is investigated.

Journal ArticleDOI
TL;DR: In this paper, a new theoretical model has been developed to explain the behavior of transverse particle transport in turbulent flow of a dilute two-phase suspension due to turbulent diffusion, which is based on the ability of a particle to respond to surrounding fluid motion and depends on particle size and density relative to the carrier fluid, the fractional variation in particle concentration in the transverse direction as well as the existing turbulence structure of the surrounding fluid.

Patent
23 Jan 1987
TL;DR: In this paper, the properties of aerofoil sectioned wings are exploited to extract energy in the form of thrust from water agitated by waves, where the wing is positioned as close as practicable to the surface, where water movement is at its maximum, and constrained against substantial movement perpendicular to the transverse chordal plane of the wing thus utilizing the kinetic energy of the moving water directly to produce a nett thrust.
Abstract: Wave energy devices which employ the properties of aerofoil sectioned wings to extract energy in the form of thrust from water agitated by waves, wherein the wing (10) is positioned as close as practicable to the surface, where water movement is at its maximum, and constrained against substantial movement perpendicular to the transverse chordal plane (17) of the wing thus utilizing the kinetic energy of the moving water directly to produce a nett thrust (16) in the chordal plane of the wing. In one form, aerofoil sectioned wings may be fitted to the hull of a ship to project laterally therefrom and be subject to wave motion. In alternative forms, aerofoil sectioned wings may be applied to rotors submerged in wave agitated water, thrust generated in the wings causing rotation of the rotor to drive a load. Support means to vary the attitude of the wings within a predetermined range of angles of attack relative to apparent flow of the water are also disclosed.