Showing papers on "Transverse plane published in 1968"

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.

Transverse Vibrations of a Moving Thin Rod

Abstract: The linearized transverse vibrations of a moving thin rod between two supports is investigated. Since the governing differential equation in the steady state is not self adjoint, the vibration frequencies and mode shapes are obtained via infinite systems of simultaneous equations using the mode functions of the corresponding stationary rod. Detailed calculations are performed for both end supports fixed and for both end supports simply supported. The energy of vibration is also investigated.

On the diffusion of load from a transverse tension-bar into a semi-infinite elastic sheet.

Abstract: : The paper deals with the load-diffusion from a tension-bar of finite length and uniform cross-section into a semi-infinite sheet, the axis of the bar being perpendicular to the edge of the sheet. The bar is regarded as a one-dimensional elastic continuum, whereas the elastic sheet is treated within the two-dimensional theory of generalized plane stress. Three alternative models for the stringer-attachment are considered: (a) line-contact; (b) area-contact based on matching the axial stringer-strain and the corresponding average sheet-strain across the width of the strip of adhesion; (c) area-contact based on matching the stringer-strain and the corresponding sheet-strain along the centerline of the strip of adhesion. It is shown that the line-contact model, in contrast to both area-contact models, does not admit the transmission of portions of the applied load through forces concentrated at the ends of the adhering bar-segment. Further, asymptotic estimates are deduced for the end-slopes of the load-diffusion curves appropriate to the three models under consideration. The integro-differential equation for the stringer-force in Case (b) and Case (c) is reduced to a standard Fredholm integral equation, which is solved numerically. The results thus obtained are compared with available experimental findings. (Author)

Transverse Vibration of a Class of Non-Uniform Beams

Abstract: The free and forced transverse vibrations of a class of non-uniform beams, which includes as special cases the wedge and cone, are considered. Receptances, frequency equations, mode shapes and natural frequencies are presented for simple end conditions.

The geomagnetic tail - Topology, reconnection and interaction with the moon

Abstract: A preliminary assessment of the geometry of the geomagnetic tail is made using data from the Ames magnetometer on the Explorer 33 satellite. The general shape corresponds to the earlier findings of Ness and coworkers. The tail is found regular to distances greater than 82 R E. The field values vary for Kp ⩽ 2 + from a low of about 4 gamma to a high value of 40 gamma. Generally the values are in the neighborhood of 10–20 gamma. A distinct skewing of the field lines away from the solar-antisolar direction is observed, such that an added component of magnetic field in the direction of planetary motion is present on both sides of the null plane. The skewing appears to be greatest near the null plane. Increase in field magnitude with increasing Kp is observed. The radial gradient can be shown to fit a power or exponential law with near equal validity. A correlation analysis of field magnitude with radial distance, ap, and transverse position coordinates also is discussed. Little cross gradient is observed in the tail field. Strong evidence for reconnection of field lines is found, and statistics are presented for a dual effect regarding the residual Z field across the null plane. Lastly the interaction of the tail field with the moon is discussed in terms of the mechanism of Sonett and Colburn.

Simultaneous phase‐locking of longitudinal and transverse laser modes

Abstract: By using a discharge tube filled with pure neon as a nonlinear element, it has been found possible to obtain simultaneous locking of both longitudinal and transverse modes of a 6328 A He–Ne laser Under certain circumstances, each transverse mode has all its longitudinal resonances phase locked to form a narrow pulse, but the pulses corresponding to the various transverse mode orders do not coincide in time Beam scanning has been observed when the frequency spacing between the transverse modes is a simple fraction of the longitudinal mode spacing Under these conditions, a ``spot'' of light traces out a zig‐zag path in the laser cavity

Excitation of Magnetoelastic Waves in YIG Delay Lines

Abstract: The excitation mechanism based on the propagation of magnetoelastic waves in axially magnetized single‐crystal samples of yttrium iron garnet (YIG), of nonellipsoidal geometry, is proposed for microwave delay lines. A qualitative theory is advanced that excitation takes place by electromagnetic energy being coupled to a spin wave through magnetostatic modes, driven at the minimum value of internal dc magnetic field. The theoretical model decomposes the guided wave propagation in a ferrimagnetic slab, between metal plates, into pairs of plane waves, which essentially propagate in an inhomogeneous and anisotropic medium. This theory is supported by experiments in which a YIG rod was precisely translated along the dc field axis, with respect to the coupling antenna. These experiments demonstrate that minimum insertion loss requires that a large transverse rf magnetic field exist at the end face of the rod, that loss increases monotonically when the coupler is moved away from the end face, and that no minimum...

Properties of thin metal films at microwave frequencies.

Abstract: Thin metal films electromagnetic properties at microwave frequencies, analyzing power transmission, reflection and absorption in transverse plane of rectangular waveguide

An ultrastructural study of vegetative cell division in oedogonium borisianum12

Abstract: SUMMARY Vegetative cell division in Oedogonium borisianum is initiated by the formation of a 3-layered ring adjacent to the wall in the upper portion of the cell. This structure enlarges by the coalescence of vesicles. When the ring is fully developed, the parent wall splits adjacent to the ring, and the ring expands into a cylinder, which becomes the cuticle of the upper daughter cell. The lateral wall then forms between this cuticle and the plasmalemma of the cell. Concurrent with ring development and expansion, the nucleus migrates to a position in the center of the cell and karyokinesis occurs. Commencing with late telophase, evidence of transverse wall formation becomes apparent. The zone between the daughter nuclei contains a layer of microtubules in a plane parallel to the plane in which the transverse wall will develop. Subsequently a random coalescence of vesicles occurs along this plane. During the latter stages of this process, the ring expands and the plane of the transverse wall moves upward to the base of the ring cylinder. The completed transverse wall then fuses at is periphery with the newly formed lateral wall.

Transverse vibrations of a clamped spinning membrane.

Abstract: Transverse vibrations of spinning disk clamped by central hub, noting hub to disk radius ratio effect on frequency parameter

Variable position means for holding a nonrotating workpiece in friction welding apparatus

Abstract: Friction welding apparatus including a pair of members having transversely facing workpiece engaging surfaces thereon for holding a nonrotating workpiece and adjusting means for varying the positions of the members relative to each other and a machine support. The adjusting means includes transverse adjusting means for selectively and independently moving the members toward or away from each other along an axis transverse to the normal welding axis and for selectively and independently moving the members as a unit in either direction along the transverse axis.

Apparatus for turning advancing flat workpieces in their plane of travel,from a longitudinal to a transverse attitude

Abstract: THE APPARATUS COMPRISES A PLURALITY OF TWO-PART TURNING DEVICES, WHICH HAVE UPPER PARTS THAT HAVE THE SAME PITCH AS THE TUBE SECTIONS AND ARE SECURED TO AN UPPER CHAIN OR SIMULAR CONVEYOR ELEMENT, WHICH REVOLVES ABOVE THE PLANE OF TRAVEL OF THE TUBE SECTIONS AT THE SAME SPEED AS THE LATTER, AND LOWER PARTS, WHICH HAVE THE SAME PITCH AND ARE CARRIED BY A LOWER CHAIN OR THE LIKE, WHICH REVOLVES BELOW THE PLANE OF TRAVEL AS THE TUBE SECTIONS AND AT THE SAME SPEED OF THE LATTER. THE DISTANCE BETWEEN THE ADJACENT COURSE OF THE TWO REVOLING CHAINS IS SUCH THAT THE TURNTABLES OF THE PARTS OF THE TURNING DEVICES ENGAGE THE TUBE SECTIONS FROM ABOVE AND BELOW AND GRIP THE TUBE SECTIONS AS SAID PARTS MOVE AROUND THE SPOCKET WHEELS. AT LEAST ONE OF THE TURNTABLES IS TURNED THROUGH 90* AS ITS CONTINUES TO MOVE SO THAT THE TUBE SECTIONS AREW TURNED FROM A LONGITUDINAL ATTITUDE TO A TRANSVERSE ONE WHILE THEY ARE MOVED JOINTLY WITH THE TURNTABLES.

Two‐Dimensional Theta‐Pinch Dynamics with Transverse Magnetic Fields

Abstract: The complete set of equations for the two‐fluid model of a fully ionized plasma, the parameters of which depend on two spatial dimensions and time, is solved by a computer program. This program is applied to the problem of plasma rotation in a theta pinch caused by transverse multipole fields. The results show that the plasma does not rotate like a cylindrical rigid body, rather the velocity varies strongly with azimuth. Moreover, the rotation changes direction along the radius. Therefore, transfer of angular momentum from outside is not necessary for the existence of rotation. Even in small transverse fields (B ∼ 500 G) the rise time for the angular velocity is of the order of 10−7 sec and very short compared with those obtained from previous theoretical models.

Optical Probing of Magnetoelastic Waves

Abstract: The use of an optical probe to observe magnetoelastic (ME) waves in yttrium iron garnet gives new information not obtainable by other methods. The interaction of the light with the elastic and magnetic parts of a transverse ME wave gives rise to some unusual polarization properties, which are explained by a simple theory of the diffraction. For the laser polarized parallel or perpendicular to the plane of diffraction, a relation is found between the laser polarization giving maximum diffracted intensity and the sign of the frequency shift of the diffracted light. For a frequency shift of given sign, the optimum laser polarization is reversed for waves on the quasielastic portions of the upper and lower branches of the ME dispersion curves. When the spin-wave component is larger (near the turning points in the bar), the optimum polarization is the same on both branches, contrary to the theory. This anomaly is probably due to the large amplitude of the ME signals used in the experiments.

Method and apparatus for straightening sheet materials

Abstract: 1,217,013. Rolling. HOESCH A.G. 5 March, 1968 [6 March, 1967; 22 Sept., 1967], No. 10741/68. Heading B5A. [Also in Division B3 A sheet of metal or other material having at least a transverse curvature is straightened by passing it between two sets of rotating, straightening rollers 1, 2 having concave and convex outer surfaces so that the sheet is deformed in the longitudinal direction beyond its elastic limit to cause the transverse curvature to be eliminated.

Perturbation Measurement of Transverse R/Q in Iris-Loaded Waveguides

Abstract: The measurement of transverse R/Q in iris-loaded waveguides by perturbation techniques is described. The underlying pertrurbation theory for resonant cavities is reviewed, and formulas for metallic needles, a sapphire rod, and a teflon bead are given, A calibration of the perturbing objects in TM/sub 010/ and TM/sub 110/ cavities shows good agreement with theory. Conventional oscillator and transmission methods are compared, and a systematic error of the oscillator method is explained. A more sensitive null method is described. A definition of the transverse R/Q is given, from which it follows that the knowledge of the longitudinal electric field component is sufficient to determine the deflecting properties of a structure. The accuracy of perturbation measurements was tested on a cavity for which the R/Q was known from computer calculations and deflection tests. It was found that the various values agree to within 20 percent. Perturbation measurements of deflectors with small coupling holes showed the theoretically predicted interaction parameters. Values close to 2.2 k/spl Omega/ /m at 2.856 GHz were measured on a 2/3 /spl pi/ wave structure with about a 2-cm beam hole.

Transverse Shearing Stress in Rectangular Plates

Abstract: By means of the plate equations developed by Eric Reissner, the transverse shearing stresses in a thin, simply-supported, rectangular plate are determined. The load distribution may be defined by any function which can be represented by a double cosine series. The solution for uniform loading is discussed in detail. Experimental results obtained by the frozen-stress technique of photoelasticity are compared with the predictions of the Reissner theory and the classical theory. The boundary conditions used are the vanishing of deflection, bending moments, and twisting moments. The results show a marked difference between the two theories near the corner zones of the plate.

A Transverse Voltage in a Longitudinal Magnetic Field in Bismuth

Abstract: A transverse voltage along the binary axis is observed in bismuth in a longitudinal magnetic field along the bisectrix direction. This voltage is found to be directly related to the tilt of electron energy ellipsoid around the binary axis. The observed transverse voltage is proportional to the longitudinal electric and magnetic fields in the classical high magnetic field region and gives a value of 8°31' for the tilt angle. This transverse voltage is relatively unaffected by the presence of impurities and can be a useful tool to estimate the tilt angle of energy ellipsoids with respect to the crystal axes in semimetals. Prediction of the sign of this transverse voltage requires an exact knowledge of the relative crystalline and field directions. The anomalous longitudinal magnetoresistance is also discussed.

The infinite cylindrical antenna in a compressible plasma

Abstract: A theoretical model of an infinite cylindrical antenna, fed by a delta-function generator and immersed in a compressible, isotropic, lossless plasma, is considered in detail. A modal solution is found for the associated wave-guide problem inside the antenna; apart from the slow mode, the wave-guide modes are grouped into three sets: optical, acoustic, and hybrid modes. The current wave on the outside wall of the antenna is separated into its components: the familiar electromagnetic wave, the "transverse electroacoustic" wave which is due to the axial oscillation of electrons near the gap, and the slow surface wave. These wave components have been calculated numerically using an IBM 1130 digital computer. It is found that the electromagnetic as well as the "transverse plasma" waves have a logarithmic singularity at the gap. It is also found that at a relatively large distance from this gap the first component decays as I/] 21, while the second component decays very rapidly to zero.

Hydromagnetic flow in a rotating straight pipe.

Abstract: A theoretical analysis is made of the flow of a conducting viscous and incompressible fluid through a straight pipe of circular cross-section flowing under a constant pressure gradient. The pipe is rotated about an axis perpendicular to it and also there is imposed a uniform magnetic field transverse to the motion. It is assumed for the purpose of mathematical analysis, the angular velocity about the axis of rotation, is small. A solution is developed by successive approximations in ascending powers of the Hartmann number, the first approximation corresponds to the non-magnetic case, formulated and discussed by Barua. The stream lines in the central plane and the projection of the stream lines on the cross-section of the pipe are compared with those in the non-magnetic case. An expression for the induced electric potential difference and sensitivity has been obtained.

Transverse mode switching and image amplification in optical masers

Abstract: Transverse mode switching is accomplished in a laser oscillating in at least one transverse mode by the injection therein of a low level seeding signal of the desired output mode. If the laser is designed to enhance transverse mode competition (i.e., the cavity geometry approaches either a concentric or plane parallel configuration), then a seeding signal of the correct frequency will cause the laser to switch (i.e., spatially lock) to oscillation entirely in the injected mode. In addition, if the cavity resonator is frequency degenerate at the frequency of a complex (i.e., many transverse modes) input signal, and if the resonator is designed to provide approximately equal gain for all of these transverse modes, then the laser will lock onto the transverse modes of the input signal and image-amplify the signal.

Optimization of a Slot End Configuration in a Finite Plate Subjected to Uniformly Distributed Load

Abstract: Two-dimensional photoelasticity is used to determine the distribution of stresses at the ends of a transverse slot symmetrically located in the uniform field of a thin birefringent strip subjected to tension. The ends of the slot are ellipses with different axes ratios, ranging from a flat ellipse to a semicircle. The stress-concentration factors are found for different ratios of the transverse width of the slot to the total width of the tensile specimen. Optimum shapes are given for each ratio of the transverse width of the slot to the total width of the tensile specimen. The results obtained may prove useful in the design of solid propellant grains.

Transverse negative differential mobilities for hot electrons and domain formation in germanium

Abstract: In n‐type germanium samples biased with a field in the range 4–10 kV/cm along (110) direction, the differential mobility along the (001) direction is found to be negative. Such transverse negative mobilities give rise to the formation of electrically polarized domains at right angles to the drift velocity of electrons. A brief discussion of the origin of negative transverse mobility is presented.

Magnetohydrodynamic flow along cylindrical pipes under non-uniform transverse magnetic fields

Abstract: The unidirectional flow of an incompressible, electrically conducting, viscous fluid along cylindrical pipes is considered. An external magnetic field, B0, which lies in the plane transverse to the flow is applied. It is shown that the governing equations, written in the co-ordinate system traced out by B0, are mathematically very similar to those for a uniform field.The paper deals mainly with ducts whose walls are insulators. Though exact solutions (valid for all values of the Hartmann number) are derived, the limit of high Hartmann number is taken for detailed discussion. Transition layers (or, loosely, ‘wakes’) can arise which are centred on curved field lines. In some cases, reversed flow occurs in part of the core (‘radial-type’ fields). Situations also arise where the magnitude (and sign) of the velocity remains the same as for B0 = 0, whatever the strength of the applied, transverse (azimuthal) magnetic field.

Elastic-plastic dynamic behavior of a beam-column model

Abstract: An elastoplastic beam-column model with one degree of freedom subjected statically to an on-center or off-center axial compressive force is considered. Its dynamic behavior in the elastoplastic range, resulting from a transverse periodic acting force in resonance with the structure in the elastic range, is examined. The principal features are highlighted by a phase plane study.