Showing papers on "Transverse plane published in 1969"

Measurement of Hip-joint Motion during Walking: Evaluation Of An Electrogoniometric Method

Abstract: An accurate, simple, and relatively inexpensive method for measuring hip-joint motion during walking with an electrogoniometer has been described. Average motion at the hip joint during walking for thirty-three normal subjects was 52 degrees in the sagittal plane, 12 degrees in the coronal plane, and 13 degrees in the transverse plane. Test-retest measurements for this method resulted in high coefficients of correlation. A typical normal pattern of motion was presented. We believe this method of measurement is practical and valuable for use in the study of hip disease.

Bending-Extensional Coupling in Laminated Plates Under Transverse Loading

Abstract: Anti-symmetric cross-ply and angle-ply laminates under transverse loading are analyzed. By expanding the load in a double Fourier series a closed form solution is obtained for special types of simp...

The effect of bends on dispersion in streams

Abstract: Bends in streams induce secondary currents that alter the rates of both transverse mixing and longitudinal dispersion. Within a bend the transverse mixing coefficient depends on the square of the mean velocity, cube of the depth, and inversely on the shear velocity and square of the radius of curvature, as verified by a laboratory experiment. The longitudinal dispersion coefficient depends on the channel geometry, velocity distribution, rate of transverse mixing, and a dimensionless parameter that includes the mean velocity and length of an average bend. A numerical program for predicting dispersion coefficients in streams differs from previous theories by including the effect of the alternating direction of curvature in a series of bends; the difference is important for wide streams but not for narrow ones. Experimental findings in two streams, the Green-Duwamish in Washington (width 20 meters), and the Missouri near Omaha, Nebraska (width 180 meters), verify the numerical program.

Resonant modes of GaAs junction lasers

Abstract: The resonant modes of GaAs junction lasers are obtained from a proposed model and compared with experimental results. Theoretical results are based on an assumed laser medium whose dielectric constant varies both along and perpendicular to the junction plane. The frequency separations of the transverse modes are found to be in very good agreement with presented high-resolution spectral measurements of stripe-geometry laser radiation. Furthermore, the theoretical field distributions are also in good agreement with observed transverse field variations reported previously. The laser output spectrum usually shows a number of "satellites" located adjacent to each longitudinal (Fabry-Perot) resonance. It is shown that each satellite represents the frequency of a transverse resonance having a different mode number along the junction plane and a corresponding Hermite-Gaussian intensity profile along the plane. Theory shows that the frequency separation of two adjacent satellites is related to the falloff rate of the dielectric constant along the junction plane. This focusing is measured from the intensity profile of a far-field pattern. From this information, the theoretical frequency separation is calculated and found to agree well with the measured separation of 6.4 GHz (0.15 A).

Fluctuations of a Beam Wave Propagating Through a Locally Homogeneous Medium

Abstract: : General formulations for the fluctuations of a beam wave propagating through a homogeneous or locally homogeneous medium are given in terms of the spectral density of the index of refraction. The amplitude and phase correlation functions and the mean square fluctuations are derived for a homogeneous medium showing the dependence on the radial distance in the transverse plane of the beam. The amplitude and phase structure functions are derived for a locally inhomogeneous medium. The correlation functions and the structure functions do not depend only on the difference coordinate, but they are functions of the radial coordinates in the beam cross section. This particular inhomogeneity, however, is shown to be an analytic continuation of the homogeneous or locally homogeneous case. The mean square amplitude fluctuation for the Kolmogorov's locally homogeneous medium is shown to behave as a plane wave for short distance and then becomes less than that of a spherical wave, and its spectrum is shown to behave as 1/K for large K in contrast with the plane and spherical waves. The spread of the beam radius is shown to be approximately the 8/3 powers of the distance L for small distance and its increase depends on the magnitude of the index of refraction fluctuation. (Author)

Transverse edge effect in sheet-rotor induction motors

Abstract: A 2-dimensional-field analysis is presented for the problem of the sheet-rotor induction motor with finite width. Account is taken of the redistribution of the air-gap flux under the action of currents which flow in the active portion of the sheet in the direction of motion. The performance is shown to depend on three dimensionless parameters which are functions of the design data and the slip. It is seen that, for certain motors, the flux redistribution can affect the performance considerably. Measurements of force and flux density made on a linear motor, although showing reasonable agreement with the analysis, suggest that it would be desirable to take into account also, at least for those motors in which severe transverse redistribution occurs, the neglected secondary leakage fluxes that exist in the end regions and within the air gap.

Large‐Amplitude Damped Free Vibration of a Stretched String

Abstract: The equations of motion of a vibrating string are derive, and it is shown that a coupling exists between the longitudinal and transverse modes of vibration. Free transverse vibration of small order, under sinusoidal initial conditions, is analyzed. Under these conditions, the equations are separable. The time‐dependent parts of the equations are solved by the method of variable amplitude and phase. It is seen that, when the vibration is nonplanar, part of the energy oscillates between the mutually perpendicular transverse components with a frequency proportional to the nonlinearity parameter α. The path of any point on the string is shown to be an ellipse with slowly rotating and shrinking axes.

Transverse Mode Locking.

Abstract: The possibility of phase locking the transverse modes of a laser is considered. It is shown that if a transverse mode set having a Poisson intensity distribution can be phase locked, a scanning laser beam can be produced.

Properties of low order transverse modes in argon ion lasers.

Abstract: A study has been conducted to determine the trade-offs among beam divergence, output power, and mirror alignment tolerances of high power argon ion lasers operating in various low order transverse modes. The radial intensity distribution and angular divergence of the actual laser modes from the active cavity have been measured and are compared with the theoretical passive cavity modes. The intensity distributions of higher order laser modes are found to differ markedly from those predicted by theory. The differences consist primarily of enhancement of the intensity of the off-axis peaks relative to that of the center peaks. These differences are caused by the relative high small-signal gain and the saturable gain characteristics of the medium. The beam divergence in free space of different transverse modes agrees very closely with that predicted for the passive cavity modes. The three lowest order transverse modes (i.e., TEM00, TEM01*, and TEM10) diverge at 1.1, 2.4, and 3.6 times the rate of a diffraction limited gaussian beam having the same diameter at the 1/e2 intensity points. The mirror alignment tolerances associated with different transverse modes have been measured for both double concave and plano concave cavity configurations using a wide variety of spherical mirrors. For a given cavity configuration, as the order of the transverse mode increases, the alignment requirements become progressively less stringent. In accordance with theory, the alignment tolerances are found to be less severe for double concave cavities than for plano concave cavities. For a given cavity configuration, higher order transverse modes have a larger beam diameter and consequently couple to a larger volume of the laser medium. Therefore, a greater power output may be obtained in a given length by using a higher order transverse mode. Data on the relative power available in different transverse modes as a function of cavity configuration are given. A knowledge of the trade-offs among beam divergence, cavity stability, and power output for different transverse modes allows the optimum transverse mode and cavity configuration for a given laser application to be selected.

Plasma flux transport.

Abstract: An electric shock tube has been used in an interaction experiment with a transverse, dc magnetic field. A simple magnetohydrodynamic analysis, assuming a conductivity of 130 mho/cm, emphasizes the importance of tensor conductivity and transverse field diffusion.

Investigation of the structure of detonation waves in gases

Abstract: The application of advanced compensating methods of photography has made it possible to obtain an undistorted picture of the luminosity fields and location of shocks in the region of a spinning detonation head. The essential elements are a transverse front moving into gas precompressed by the primary shock. Calculation of the flow near triple points that appear due to interaction of the transverse front and the primary shock has been made. The correctness of the accepted hydrodynamic configuration has been confirmed by pressure-profile measurements with small piezoceramic gauges. The specific configurations, similar to spinning detonation, have been revealed in multi-headed detonation in a flat channel. Luminosity of the transverse fronts ceases only in unstable regimes associated with the local or general attenuation of the detonation wave. The analysis of the transverse wave regularities in three-dimensional cases allows one to assume that burning in detonation waves is again caused mainly by the transverse waves. Further study of transverse waves has permitted us to obtain a long-duration detonation process—a continuous detonation. The basis of this new process is a transverse wave rotating in a circular channel.

Transverse edge effects in linear induction motors

Abstract: Currents in the secondary member of a linear induction motor flow in roughly elliptical paths. The secondary appears to have a resistivity greater than the natural value, and the cross-gap flux density peaks towards the edges of the stators. This phenomenon is known as the transverse edge effect. In most previous work, the edge effect has been allowed for only by the use of a resistivity-increase factor. This paper gives a more exact treatment. The method used takes account of flux leakage in the space between the stators and the secondary member, and in the secondary itself. Some approximation is necessary in the treatment of the machine end-turn flux. Equations are derived for the flux-density distribution in the air gap and for thrust, in each case as a function of stator current. Static-field measurements on two linear induction devices of different design, and with secondaries of different materials, showed good correlation for the two frequencies used, except at the extreme edges. In a simulated dynamic test using a rotary machine, calculated and measured field distributions and forces agreed well over the whole slip range

Effect of Shear and Load Behavior on Ring Stability

Abstract: The problem of buckling of a thin circular ring under uniform external transverse loading is investigated for the force normal to the deformed ring, the force parallel to its initial direction, and the force directed toward the initial center of curvature. Results are derived through a simple treatment within the framework of thin ring theory and without the assumption of inextensionality. It is assumed that the uniform pressure is applied quasistatically, the material is linearly elastic, and the strains are small while the rotations are moderate. In addition, the effect of transverse shear deformation is included.

Resonant modes of GaAs junction lasers - II: High-injection level

Abstract: Previous work on the resonant modes of GaAs junction lasers operating near threshold is extended to include spectra obtained at currents 15 to 3 times the threshold level At these currents, two families of modes are shown to oscillate simultaneously with different center frequencies The modal families are demonstrated to correspond to different mode numbers in the direction perpendicular to the junction plane These observations are found to be in agreement with a previously reported theory for the GaAs laser cavity, which allows a dielectric constant variation in both directions transverse to the laser axis The general characteristics of the observed spectra are explained qualitatively in terms of a derived mode dependence of the steady-state gain function It is suggested that the strong frequency dependence of the spatial gain distribution perpendicular to the junction plane can allow two modal families with different mode numbers perpendicular to the junction to oscillate simultaneously with different center frequencies

Standing Alfvn Waves in the Magnetosphere

Abstract: Transverse, low-frequency oscillations in the magnetic field have been recorded in the equatorial plane at 66 Rr (earth radii) with the UCLA magnetometer on board ATS 1 The oscillations have peak-to-peak amplitudes of 2 to 20 y and have been observed predominantly on geomagnetically quiet days in the morning and noon quadrants The fluctuations are very nearly monochromatic, and those with periods ranging from 50 to 300 sec have been studied This paper reports on observations made during January 1967, when 25 separate events were recorded with durations ranging from 10 to 400 min The oscillations could be grouped into two period ranges, one centered about T _-- 190 sec and the other about T _-- 102 sec The oscillations were confined to a plane that was approximately perpendicular to the main magnetic field vector They were generally elliptically polarized in this plane, with the major axis of the polarization ellipse typically inclined eastward at an angle of _30 o to the radially outward direction An MHD analysis is given for an idealized model in which the earth is considered a perfect conductor, the background magnetic field is that of a dipole, and the plasma

Three-Dimensional Electromagnetic Scattering from a Circular Tube of Finite Length

Abstract: An electromagnetic plane wave in either E or H polarization is normally incident on a cylinder which is assumed to be an infinitely thin‐walled, perfectly conducting, circular tube of finite length with complete generality both in radius and length. For either polarization both axial and transverse currents are induced. The problem is transformed into determining an infinity of Fourier components by expanding each function of θ into a Fourier series. For each Fourier component a pair of integral equations for the total currents is obtained. These are decoupled in a special sense permitting the transverse total current to be obtained first, followed by the axial total current. The diflerence current is then defined and expressed in terms of the total current, making possible the determination of the inside and the outside total current. These are experimentally measurab e quantities. The theoretical formulas for the scattered fields, the far field patterns, and the scattering cross sections are also derived in terms of the total current. Finally, sample results, both theoretical and experimental, are included.

The flow induced by the transverse motion of a thin disk in its own plane through a contained rapidly rotating viscous liquid

Abstract: A thin circular disk translates slowly in its own plane transverse to the axis of rotation of parallel plane boundaries filled with viscous incompressible liquid. It is shown that the indeterminateness of the geostrophic flow is removed by constraints imposed by the dynamics of free shear layers (Stewartson layers), which surround a Taylor column whose boundary is not a stream surface. Fluid particles cross the Taylor column at the expense of deflexion through a finite angle. A comparison is made with the flow past a fat body (Jacobs 1964), where the geostrophic flow is determined without appeal to the dynamics of the shear layers. The problem is also considered for a disk in an unbounded fluid, and it is shown that to leading order there is no disturbance.

Cable support tray system

Abstract: A cable support tray and tray system for the support of cables, tubes and the like, comprised of parallel longitudinal rail sections connected by transverse rungs, which support the cables, tubes, pipes, etc., in a longitudinal direction corresponding to the direction of the rails, and in which the rungs are constructed and arranged so as to accommodate fastening means in such manner as not to protrude beyond the general plane of the cable trays.

Transverse Kerr Magneto‐Optic Effect and Optical Properties of Transition‐Rare‐Earth Alloys

Abstract: The transverse Kerr magneto‐optic effect and optical properties have been measured in Fe and GdFe5 for the optical wavelength range of 0.35 to 1.0 μ. The metals were evaporated onto the base of glass prisms at 1×10−9 mm Hg vacuum. The properties were measured at two angles of incidence. The maximum transverse Kerr effect at a 60° angle of incidence is 5.55% for Fe and occurs at 0.7 μ. The maximum transverse Kerr effect at a 60° angle of incidence for GdFe5 is 1.9% and occurs at 0.65 μ. From the experimental measurements, the spectral distribution of the diagonal and off‐diagonal components of the dielectric tensor were determined. Structure indicative of optical transitions was found in the absorptive parts of both components for GdFe5 but was absent for Fe. A discussion is given relating this structure to the conduction electrons in Gd.

Transverse magneto-plasma wave propagation in a periodic structure

Abstract: The propagation of transverse magneto-plasma waves in an absorptive plasma whose density is spatially periodic has been investigated. Numerical results are presented where the real and imaginary parts of the wave vector are studied as a function of the electronic collision frequency for a metal-semiconductor sandwich structure. These results show that scattering can play a major role in determining the dispersion relationship of plasma waves in a periodic structure. The source of the effects introduced by scattering is discussed, together with some comments concerning their implications for a proposed tunable microwave filter.

Non-linear transverse vibrations and waves in spinning membrane discs☆

Abstract: Two exact solutions are obtained to non-linear equations governing transverse motions of spinning circular membrane discs. One solution is a vibration having two nodal diameters and no nodal circles. The other is a transverse wave of the same shape which travels circumferentially around the membrane. The membrane is whole at its center and its edge is free. Results are compared with solutions from linear theories.

The effect of water on some properties of oriented nylon

Abstract: Samples of 66 nylon were oriented by rolling to produce structures in which the polymer chains are preferentially in the machine direction and the hydrogen bonds are in the transverse direction. Conditioning to 50 or 100% relative humidity (R.H.) produces anisotropic swelling with the transverse direction expanding much less than the other two directions. The dependence on temperature of the tensile modulus in the machine and transverse directions was examined for specimens which were dry, conditioned to 50% R.H., and saturated with water. At high temperatures, the modulus was larger in the transverse direction. At-40°C, it was larger in the machine direction and increased with increasing moisture. The data are interpreted in terms of crystals which have their largest dimension in the hydrogen bond direction.

Slope diffraction analysis of TEM parallel-plate guide radiation patterns

Abstract: The radiation pattern of the transverse electromagnetic- (TEM) mode parallel-plate waveguide is analyzed by the wedge-diffraction theory in conjunction with a slope-correction term. This term takes into account the nonuniform wave in the analysis of second-order diffractions for an open-ended guide. This slope-correction term provides improved accuracy of the pattern in the region near the plane of the aperture when compared to the usual wedge-diffraction method.

Vehicle stabilization apparatus

Abstract: A controlled pendulum is utilized to automatically tilt a vehicle frame uphill to compensate for transverse inclination of the terrain on which the vehicle is riding. The normal gravitational forces exerted on the pendulum due to such transverse inclination are partially counteracted by tension forces proportional to the degree of inclination. The frame is thereby tilted uphill an angular amount in proportion to the amount of transverse inclination encountered. The vehicle frame is pivoted to a ground engaging structure about a longitudinal axis. The pendulum is pivoted about an elevated parallel axis. A pair of control devices are mounted to the frame to detect pendulum movement to either side of a plane containing said axes. Tension springs extend outwardly and downwardly from the pendulum to the vehicle''s ground engaging structure. They serve to force the pendulum to an equilibrium condition at an angle relative to the vertical. The monitoring function of the control devices causes the frame to be aligned along this plane which is inclined uphill.

Stationary Electric Arc in a Cross‐Flow and Transverse Magnetic Field

Abstract: An electric are is held stationary against a gas flowing transverse to the arc axis by applying a magnetic field perpendicular both to the arc axis and the direction of the gas flow. A theoretical analysis of the problem is undertaken for the case where the arc is sufficiently long for a central region of the arc (called the uniform column) to exist where a two‐dimensional treatment, in the plane of the gas flow, is adequate. The Reynolds number of the flow is taken to be small compared with one. The technique of matched asymptotic expansions is used to calculate the two‐dimensional distributions of the quantities of interest, e.g., the temperature and velocity of the gas.

Continuous crystallizing apparatus for sugar-bearing liquor

Abstract: A crystallizer for sugar has a shell which is approximately cylindrical about a horizontal axis, and symmetrical relative to a vertical plane through the axis. A group of plate-shaped heating elements in the shell define a horizontal plane which upwardly bounds the group and divides the interior of the shell into a top portion and a bottom portion. The numerical value of the combined surface area in square meters of the heating elements which are upright and parallel to the axis is 13 to 20 times the numerical value of the capacity of the bottom portion in cubic meters, and the capacity of the bottom portion is 0.2 to 0.35 times the total capacity of the shell. The bottom portion is axially divided into compartments by partitions transverse to the axis.

Cutting tool insert

Abstract: A cutting tool insert formed from a cylindrical blank to include a cutting edge in an axial plane across at least one end thereof and having a chip control relief therebehind and extending relatively below the cutting edge plane to provide side clearance.