Showing papers on "Rotation published in 1999"

Synchronized Formation Rotation and Attitude Control of Multiple Free-Flying Spacecraft

Abstract: Intheobservationslewingoflongbaselineinterferometersformedbymultiplefree-e yingspacecraftinformation, it is required to rotate the entire formation about a given axis and to synchronize individual spacecraft rotation with formation rotation. Using a particle model for spacecraft formation dynamics and a rigid-body model for spacecraft attitude dynamics, control laws are derived for this mode of operation in the absence of a gravitational e eld and disturbances. A simplie ed control law suitablefor implementation isalso obtained. It is shown thatunder mild conditionstheformation alignmenterrordecaystozeroexponentiallywith time. Computersimulationstudies are made for a free-e ying spacecraft triad in a triangular formation. The results show that the developed control laws are effective in synchronized formation rotation.

Central rotation curves of spiral galaxies

Abstract: We present high-resolution central-to-outer rotation curves for Sb, SBb, Sc, and SBc galaxies. We discuss their general characteristics, particularly their central behavior, as well as dependencies on morphological types, activity, and peculiarity. The rotation curves generally show a steep nuclear rise and high-velocity central rotation, followed by a broad maximum in the disk and then a flat rotation due to the massive halo. Since the central high velocity and steep rise are common to all massive galaxies, they cannot be due to noncircular motions. Disk rotation curves of barred galaxies show larger dispersion than those of normal galaxies, probably because of noncircular motions. Interacting galaxies often show perturbed outer rotation curves, while their central rotation shows no particular peculiarity. In addition, central activities, such as starbursts and active galactic nuclei, appear to show no particular correlation with the property of rotation curves. This would suggest that the central activities are triggered by a more local effect than the global dynamical property.

Helioseismic Constraints on the Structure of the Solar Tachocline

Abstract: This paper presents a series of helioseismic inversions aimed at determining with the highest possible confidence and accuracy the structure of the rotational shear layer (the tachocline) located beneath the base of the solar convective envelope. We are particularly interested in identifying features of the inversions that are robust properties of the data, in the sense of not being overly influenced by the choice of analysis methods. Toward this aim we carry out two types of two-dimensional linear inversions, namely Regularized Least-Squares (RLS) and Subtractive Optimally Localized Averages (SOLA), the latter formulated in terms of either the rotation rate or its radial gradient. We also perform nonlinear parametric least-squares fits using a genetic algorithm-based forward modeling technique. The sensitivity of each method is thoroughly tested on synthetic data. The three methods are then used on the LOWL 2 yr frequency-splitting data set. The tachocline is found to have an equatorial thickness of w/R☉ = 0.039 ± 0.013 and equatorial central radius rc/R☉ = 0.693 ± 0.002. All three techniques also indicate that the tachocline is prolate, with a difference in central radius Δrc/R☉ 0.024 ± 0.004 between latitude 60° and the equator. Assuming uncorrelated and normally distributed errors, a strictly spherical tachocline can be rejected at the 99% confidence level. No statistically significant variation in tachocline thickness with latitude is found. Implications of these results for hydrodynamical and magnetohydrodynamical models of the solar tachocline are discussed.

Dry powder inhaler

Abstract: A metering device suitable for use in a dry powder inhaler comprises a housing defining a reservoir The reservoir contains a powder A rotatable auger, having a first and second end, has one or more flutes extending between the ends The first end of the auger communicates with the reservoir A dosing member, defining a dosing recess having a desired volume, is positionable adjacent said second end of said auger Rotation of said auger causes the powder to be transferred through the flutes and into the dosing recess to fill the recess volume with a specific dose of powder

Bose-Einstein condensates with vortices in rotating traps

Abstract: We investigate minimal energy solutions with vortices for an interacting Bose-Einstein condensate in a rotating trap. The atoms are strongly confined along the axis of rotation z, leading to an effective 2D situation in the x-y plane. We first use a simple numerical algorithm converging to local minima of energy. Inspired by the numerical results we present a variational ansatz in the regime where the interaction energy per particle is stronger than the quantum of vibration in the harmonic trap in the x-y plane, the so-called Thomas-Fermi regime. This ansatz allows an easy calculation of the energy of the vortices as function of the rotation frequency of the trap; it gives a physical understanding of the stabilisation of vortices by rotation of the trap and of the spatial arrangement of vortex cores. We also present analytical results concerning the possibility of detecting vortices by a time-of-flight measurement or by interference effects. In the final section we give numerical results for a 3D configuration.

Hybrid energy recovery system

Abstract: A system for recovering energy from the natural and man made sources of wind, water and sunshine provides within a given local area wind, water and solar apparatuses for converting all three wind, water and solar energies to electrical power to provide a reasonably steady supply of electrical power at all times. The wind and water apparatuses may be double speed Savonius rotor electrical generating apparatuses each of which includes two Savonius type rotors mounted adjacent to one another for rotation about a common axis with the blades of the rotor units being arranged so that the rotor units rotate in opposite directions relative to one another under the influence of a given wind or flow of water. The electrical generator of each apparatus includes a field means attached to one of the two rotors and an armature attached to the other of the two rotors so that the field means and armature rotate relative to one another at a speed approximately double the speed of rotation of each of the rotor units about the common rotational axis.

Apparatus and method for providing spherical viewing during endoscopic procedures

Abstract: The present invention is an improved apparatus and method for providing variable-angle endoscopic views in a cavity, such as an internal cavity in a human patient. The apparatus includes an elongated tubular portion with a viewer at its proximal end and a reflector assembly at its distal end. The reflector assembly includes a first reflector and a second reflector, with the second reflector rotationally mounted to permit its rotation about an axis generally aligned with an optical path portion passing from the first reflector to the second reflector. The viewer is preferably a camera rotatably secured to the apparatus. A rotator controls rotation of the second reflector and the camera, so that rotation of the second reflector causes a corresponding rotation of the camera. The assembly thus permits near-spherical viewing of the cavity without requiring substantial movement of the endoscope.

Structure and vibrational dynamics of the benzene dimer

Abstract: Point-wise evaluated coupled-cluster single double triple [CCSD(T)] stabilization energies are used to parameterize the nonempirical model (NEMO) empirical intermolecular potential of the benzene dimer in the ground electronic state. The potential is used for theoretical interpretation of the dimer structure and the dynamics of its intermolecular motions. Only one energy minimum, corresponding to the T-shaped structure, is found. A parallel displaced structure is the first-order transition structure separating the molecular symmetrically equivalent T-shaped structures. Due to a relatively high transition barrier (∼170 cm−1), the interconversion tunneling is unimportant in the energy region spanned by the available rotational spectra and is thus neglected (accordingly, the molecular symmetry group which is used for interpretation of the available experimental spectra is related to the T-shaped structure with two feasible internal rotations and nonequivalent monomers). The dimer undergoes a nearly free internal rotation along the axis connecting the benzene centers of mass in the T-shaped equilibrium geometry and a hindered internal rotation (the barrier being ∼46 cm−1) along the axis that is perpendicular to the “nearly free” internal rotation axis. The tunneling splittings observed in the rotational spectrum are likely due to this hindered rotation. An analysis assuming the latter rotation as an independent motion and using purely vibrational tunneling splittings (obtained by extrapolating to zero values of the rotational quantum numbers) indicates that the genuine value of the hindered rotation barrier is nearly twice higher than its ab initio value. Similarly, the difference ΔR=0.25 A between the ab initio (equilibrium) and experimental (ground state) values for the distance of the mass centers of the benzene monomers is strong evidence that our theoretical potential is much shallower than the genuine one. The Raman bands observed at the 3–10 cm−1 region seem to involve states associated with the nearly free rotation and the “energy minimum path” bending motion. Unambiguous assigning of the weaker Raman features is infeasible, partly due to limitations in the accuracy of the theoretical potential, and partly due to the lack of knowledge of the polarizability tensor of the dimer and temperature at which the spectra were taken.

Dual-mass micromachined vibratory rate gyroscope

Abstract: A microfabricated gyroscopic sensor for measuring rotation about a Z-axis. The sensor includes a substrate, a first mass, a second mass, a coupling system connecting the first mass and the second mass, and a suspension system connecting the first mass and the second mass to the substrate. The sensor further includes a drive system to cause the first mass and the second mass to vibrate in an antiphase mode along a drive axis, and a position sensor to measure a displacement of the first mass and the second mass along a sense axis perpendicular to the drive axis and generally parallel to the surface of the substrate, wherein rotation of the first mass and the second mass about the Z-axis perpendicular to the surface of the substrate and vibration of the first mass and the second mass along the drive axis generates a Coriolis force to vibrate the first mass and the second mass along the sense axis in antiphase to each other.

The Second-Parameter Effect in Metal-Rich Globular Clusters

Abstract: Recent Hubble Space Telescope observations have found that the horizontal branches (HB's) in the metal-rich globular clusters NGC 6388 and NGC 6441 slope upward with decreasing B-V. Such a slope is not predicted by canonical HB models and cannot be produced by either a greater cluster age or enhanced mass loss along the red-giant branch (RGB). The peculiar HB morphology in these clusters may provide an important clue for understanding the second-parameter effect. We have carried out extensive evolutionary calculations and numerical simulations in order to explore three non-canonical scenarios for explaining the sloped HB's in NGC 6388 and NGC 6441: i) A high cluster helium abundance scenario, where the HB evolution is characterized by long blue loops; ii) A rotation scenario, where internal rotation during the RGB phase increases the HB core mass; iii) A helium-mixing scenario, where deep mixing on the RGB enhances the envelope helium abundance. All three of these scenarios predict sloped HB's with anomalously bright RR Lyrae variables. We compare this prediction with the properties of the two known RR Lyrae variables in NGC 6388. Other possible observational tests are suggested.

Bony tissue resector

Abstract: The present invention provides a system (12) for resecting bony tissue such as the facet joint processes (18) using a cannulated resector held by a guidance platform (11). Rotation of the support holding the cannula (14) causes the resecting surface of a rotating burr (16) to move into contact with the facet joint.

Coordinate input stylus

Abstract: A stylus for use in a coordinate input system (e.g. digitizer tablet system) includes a finger wheel. The degree of rotation of the finger wheel by the user determines the extent to which a chosen graphical parameter (e.g. line thickness, color, shading, gray scale, etc.) is varied. Thus, a user can easily vary the graphical parameter while drawing by merely rotating the finger wheel about its fixed rotational axis. Preferably, rotation of the wheel causes an intermediate gear wheel with teeth thereon to rotate which in turn causes a potentiometer to detect the degree of rotation of the finger wheel. In alternative embodiments of this invention, a touchpad for inputting finger position and/or finger pressure information may be provided on the side of the stylus instead of the finger wheel.

Central impurity toroidal rotation in ICRF heated Alcator C-Mod plasmas

Abstract: Central impurity toroidal rotation has been observed in Alcator C-Mod ICRF heated plasmas, from the Doppler shifts of argon X ray lines. Rotation velocities of up to 1.3 × 105 m/s in the co-current direction have been observed in H mode discharges with no direct momentum input. There is a strong correlation between the increase in the central impurity rotation velocity and the increase in the plasma stored energy, induced by ICRF heating, although other factors may be involved. This implies a close association between energy and momentum confinement. Co-current rotation is also observed during purely ohmic H modes. In otherwise similar discharges with the same stored energy increase, plasmas with lower current rotate faster. For hydrogen minority (D(H)) heating, plasmas with the highest rotation have an H/D ratio between 5 and 10% and have the resonance location in the inner half of the plasma, i.e. in the same conditions that are conducive to the best ICRF absorption and heating. Comparisons with neoclassical theory indicate that the ion pressure gradient is an unimportant contributor to the central impurity rotation and the presence of a substantial core radial electric field is inferred during the ICRF pulse. An inward shift of ions induced by ICRF waves could give rise to a non-ambipolar electric field in the plasma core.

Method of producing liquid crystal display panel

Abstract: PROBLEM TO BE SOLVED: To prevent stripe alignment failures in a liquid crystal display panel having a columnar spacer. SOLUTION: A color filter substrate 1 having a columnar spacer 3 is subjected to rubbing by using a rubbing roll 17. If the color filter substrate 1 is sent only in the rotation direction while the rubbing roll 17 is rotated, alignment failures are caused from the bottom of the columnar spacer 3, and therefore, the color filter 1 is first sent to the direction 21 and then sent to the direction 22. Thus, a part with insufficient rubbing is eliminated and uniform display is possible. COPYRIGHT: (C)2001,JPO

Ink-jet recording apparatus

Abstract: PROBLEM TO BE SOLVED: To send out a paper without disturbing images on the paper by providing a means rotating a middle spur when the paper is transferred while caught by a plurality of rollers, spurs opposite to the rollers and the middle spur not facing the rollers arranged at the downstream side of a recording head. SOLUTION: In order to carry out a paper after recorded by a recording head, a plurality of paper discharge rollers 26 are arranged intermittently in a breadthwise direction of the paper and moreover, a plurality of spur units 27 are provided on a shaft 46 extending in parallel via a space to a paper discharge roller shaft 41. Two spurs 42 facing the paper discharge rollers 26 and one middle spur 43 not facing the paper discharge rollers 26 are integrally arranged on a hollow shaft 44 to constitute the spur unit. Each spur unit 27 is urged by the action of an elastic member 45 such as a leaf spring, etc., towards the paper discharge roller 26. Accordingly, the paper receiving a nip force generated between the paper discharge rollers 26 and spurs 42 is transferred by the rotation of the paper discharge rollers 26. A stable transfer is ensured because of the synchronously rotated middle spur 43.

Angular Momentum Transport in Magnetized Stellar Radiative Zones. IV. Ferraro's Theorem and the Solar Tachocline

Abstract: We consider the circumstances under which the latitudinal differential rotation of the solar convective envelope can (or cannot) be imprinted on the underlying radiative core through the agency of a hypothetical weak, large-scale poloidal magnetic field threading the solar radiative interior. We do so by constructing steady, two-dimensional axisymmetric solutions to the coupled momentum and induction equations under the assumption of a purely zonal flow and time-independent poloidal magnetic field. Our results show that the structure of the interior solutions is entirely determined by the boundary conditions imposed at the core-envelope interface. Specifically, in the high Reynolds number regime a poloidal field having a nonzero component normal to the core-envelope interface can lead to the transmission of significant differential rotation into the radiative interior. In contrast, for a poloidal field that is contained entirely within the radiative core, any differential rotation is confined to a thin magnetoviscous boundary layer located immediately beneath the interface, as well as along the rotation/magnetic axis. We argue that a magnetically decoupled configuration is more likely to be realized in the solar interior. Consequently, the helioseismically inferred lack of differential rotation in the radiative core does not necessarily preclude the existence of a weak, large-scale poloidal field therein. We suggest that such a field may well be dynamically significant in determining the structure of the solar tachocline.

Time-Optimal Control of Axisymmetric Rigid Spacecraft Using Two Controls

Abstract: In this paper, we consider the minimum-time reorientation problem of an axisymmetric rigid spacecraft with two independent control torques mounted perpendicular to the spacecraft symmetry axis. The objective is to reorient the spacecraft from an initial attitude, with some angular velocity, to a e nal attitude with a certain angular velocity in minimum time. All possible control structures, including both singular and nonsingular arcs, arestudied completely byderivingthecorrespondingformulasand thenecessary optimality conditions. Itisshown that a second-order singular control can be part of the optimal trajectory. It is also shown that for an inertially symmetric and a nonspinning axisymmetric rigid body, it is possible for ine nite-order singular controls to be part of or the whole optimal trajectory. In particular, for a nonspinning axisymmetric rigid body, the second-order singular trajectory is shown to be an eigenaxis rotation. An efe cient method for numerically solving the optimal controlproblem,basedonacascadedcomputationalschemethatusesbotha directmethodand anindirectmethod, is also presented. Numerical examples demonstrate optimal reorientation maneuvers with both nonsingular and singular subarcs, and comparisons are made between eigenaxis rotations and the true time-optimal rotations.

CCS Imaging of the Starless Core L1544: An Envelope with Infall and Rotation

Abstract: We have carried out observations of the starless core L1544 in the CCS (JN = 32-21) line at 9 mm wavelength using the Berkeley-Illinois-Maryland Association array. The maps show an elongated condensation, 0.15×0.045 pc in size, with stronger emission at the edges. The appearance is consistent with a flattened, ringlike structure viewed at high inclination to the line of sight. The CCS molecule is likely heavily depleted in the inner part of the core. The position velocity diagram along the major axis shows a remarkable pattern, a "tilted ellipse," that can be reproduced by a simple model ring with motions of both infall and rotation. The models suggest comparable velocities for infall and rotation, ~0.1 km s-1, in the outermost envelope, at radius 15,000 AU.

Device for rotatably positioning a camera or similar article about two orthogonal axes

Abstract: A positioning device (100) is provided for rotatably positioning a camera (102) or other article about orthogonal rotational axis by a yoke (106) The yoke (106) is in turn rotatably coupled to a base assembly for rotation of the yoke about a vertical axis Rotation of the camera about the horizontal and vertical axes is respectively effected by first and second voice coil actuators (110 and 112), each comprising a pair of magnets and at least one coil to which current is supplied The amplitude and direction of the current supplied to the coil determines the speed and direction of rotation of the camera The second voice coil actuator preferably includes a coil assembly comprising two opposed coils This design overcomes the angular range limitations associated with prior art voice coil actuator and enables rotation of the camera about an extended angular range The device can be advantageously utilized for adjustment of pan and tilt angles of a video camera in a conferencing system

Superfluid Hydrodynamic Model for the Enhanced Moments of Inertia of Molecules in Liquid 4 He

Abstract: We present a superfluid hydrodynamic model for the increase in moment of inertia, $\Delta I$, of molecules rotating in liquid $^4$He. The static inhomogeneous He density around each molecule (calculated using the Orsay-Paris liquid $^4$He density functional) is assumed to adiabatically follow the rotation of the molecule. We find that the $\Delta I$ values created by the viscousless and irrotational flow are in good agreement with the observed increases for several molecules [ OCS, (HCN)$_2$, HCCCN, and HCCCH$_3$ ]. For HCN and HCCH, our model substantially overestimates $\Delta I$. This is likely to result from a (partial) breakdown of the adiabatic following approximation.

Direct numerical simulations of turbulence with confinement and rotation

Abstract: The goal of this work is to analyse how solid body rotation affects forced turbulence enclosed within solid boundaries, and to compare it to results of the experiment performed by Hopfinger et al. (1982). In order to identify various mechanisms associated with rotation, confinement, and forcing, a numerical pseudo-spectral code is used for performing direct numerical simulations. The geometry is simplified with respect to the experimental one. First, we are able to reproduce the linear regime, as propagating inertial waves that undergo reflections at the walls. Second, the Ekman pumping phenomenon, proportional to the rotation rate, is identified in freely decaying turbulence, for which the evolution of the flow bounded by walls is compared to the evolution of unbounded homogeneous turbulence. Finally we introduce a local forcing on a plane in physical space, for simulating the effect of an oscillating grid, so that diffusive turbulence is created, and we examine the structuring of the flow under the combination of the linear and nonlinear mechanisms. A transition to an almost two-dimensional state is shown to occur between the region close to the forcing and an outer region in which vortices appear, the number of which depends on the Reynolds and Rossby numbers. In this region, the anisotropy of turbulence is examined, and the numerical predictions are shown to reproduce many of the most important features present in the experimental flow.

The Pattern Speed of the Galactic Bar

Abstract: Most late-type stars in the solar neighborhood have velocities similar to the local standard of rest (LSR), but there is a clearly separated secondary component corresponding to a slower rotation and a mean outward motion. Detailed simulations of the response of a stellar disk to a central bar show that such a bimodality is expected from outer Lindblad resonant scattering. When constraining the run of the rotation curve by the proper motion of Sagittarius A* and the terminal gas velocities, the value observed for the rotation velocity separating the two components results in a value of 53 ± 3 km s-1 kpc-1 for the pattern speed of the bar, only weakly dependent on the precise values for R0 and bar angle .

Effect of field size, head motion, and rotational velocity on roll vection and illusory self-tilt in a tumbling room.

Abstract: The effect of field size, velocity, and visual fixation upon the perception of self-body rotation and tilt was examined in a rotating furnished room. Subjects sat in a stationary chair in the furnished room which could be rotated about the body roll axis. For full-field conditions, complete 360 degrees body rotation (tumbling) was the most common sensation (felt by 80% of subjects). Constant tilt or partial tumbling (less than 360 degrees rotation) occurred more frequently with a small field of view (20 deg). The number of subjects who experienced complete tumbling increased with increases in field of view and room velocity (for velocities between 15 and 30 degrees s-1). The speed of perceived self-rotation relative to room rotation also increased with increasing field of view.

Dual-mass vibratory rate gyroscope with suppressed translational acceleration response and quadrature-error correction capability

Abstract: A microfabricated vibratory rate gyroscope to measure rotation includes two proof-masses mounted in a suspension system anchored to a substrate. The suspension has two principal modes of compliance, one of which is driven into oscillation. The driven oscillation combined with rotation of the substrate about an axis perpendicular to the substrate results in Coriolis acceleration along the other mode of compliance, the sense-mode. The sense-mode is designed to respond to Coriolis accelerationwhile suppressing the response to translational acceleration. This is accomplished using one or more rigid levers connecting the two proof-masses. The lever allows the proof-masses to move in opposite directions in response to Coriolis acceleration. The invention includes a means for canceling errors, termed quadrature error, due to imperfections in implementation of the sensor. Quadrature-error cancellation utilizes electrostatic forces to cancel out undesired sense-axis motion in phase with drive-mode position.

CFHT Adaptive Optics Observations of the Central Kinematics in M15

Abstract: We have used an Imaging Fabry-Perot Spectrophotometer with the Adaptive Optics Bonnette on the Canada-France-Hawaii Telescope to measure stellar radial velocities in the globular cluster M15. An average seeing of 0.15" full-width at half maximum, with the best-seeing image having 0.09", allowed us to measure accurately the velocities for five stars within 1" of the center of M15. Our estimate of the second moment of the velocity distribution inside a radius of 2" is 11.5 km/s, the same value we find out to a radius of about 6". However, the projected net rotation does increase dramatically at small radii, as our previous observations led us to suspect. The rotation amplitude inside a radius of 3.4" is v = 10.4 +- 2.7 km/s and the dispersion after removing the rotation is sigma = 10.3 +- 1.4 km/s, so v/sigma = 1 in this region. In addition, the position angle (PA) of the projected rotation axis differs by 100 degrees from that of the net cluster rotation at larger radii. Current theoretical models do not predict either this large an increase in the rotation amplitude or such a change in the PA. However, a central mass concentration, such as a black hole, could possibly sustain such a configuration. The rotation increase is consistent with the existence of a central dark mass concentration equal to 2500 M_solar.

Floating apparatus and method for extracting power from sea waves

Abstract: An apparatus for extracting power from ocean waves comprises a number of buoyant cylindrical body members (2, 3, 4) connected together at their ends to form an articulated chain-like structure (1). Each pair of adjacent cylindrical members is connected to each other by a coupling member (5a, 5b) which permits relative rotational movement of the cylindrical members about at least one transverse axis (40). Adjacent coupling members may permit relative rotation about mutually orthogonal transverse axes (A, B). Each coupling member is provided with elements such as a set of hydraulic rams (33, 34, 35) which resist and extract power from the relative rotational movement of the body members, and which can provide applied constraints to rotation about one or both of the transverse axes. The transverse axes of rotation (A, B) are skewed from the horizontal (41) and vertical (42) by a roll bias angle (γ), selected to optimise the dynamic response of the apparatus to incoming waves. The roll bias angle (γ) is applied by differential ballasting of the body members (2, 3, 4) and/or mooring constraints.

A Possible Mechanism for the Eye Rotation of Typhoon Herb

Abstract: An elliptical eye that rotated cyclonically with a period of approximately 144 minutes in Typhoon Herb 1996 was documented. The elliptical region had a semimajor axis of 30 km and a semiminor axis of 20 km. Two complete periods of approximately 144 min were observed in the Doppler radar data. The rotation of the elliptical eye in the context of barotropic dynamics at three levels were explored: linear waves on a Rankin vortex, a nonlinear Kirchhoff vortex, and with a nonlinear spectral model. The linear wave theory involves the existence of both the high (potential) vorticity gradient near the eye edge and the cyclonic mean tangential flow in the typhoon. The propagation of (potential) vorticity waves in the cyclonic mean flow makes the elliptical eye rotate cyclonically. The rotation period is longer than the period of a parcel trajectory moving in the cyclonic mean flow around the circumference, because the vorticity wave propagates upwind. The nonlinear theory stems from the rotation of Kirchhoff’s vortex. Estimates of the eye rotation period from both linear and nonlinear theories agree with observations of the eye rotation period when the observed maximum wind from Herb is used. Nonlinear numerical computations suggest the importance of the interaction of neutral vorticity waves, which determine the shape and the rotation period of the eye. The calculations also support the rotation of the eye in approximately 144 min in the presence of axisymmetrization, vorticity redistribution, wave breaking, and vortex merging processes.

X-ray diagnosis apparatus

Abstract: An X-ray generator is rotatably attached to one end of a C-shaped arm, and a planar X-ray detector is attached to the other end of the C-shaped arm via a link mechanism capable of freely changing a position/direction of the detector. The X-ray generator is rotated to achieve imaging in an oblique direction, without sliding/rotating the C-shaped arm. The link mechanism is driven in association with the rotation of the X-ray generator so that the X-ray detector may face the X-ray generator. Thus, the limit to the slide angle range can substantially be eliminated without degrading accessibility, and various positioning is achieved exactly and easily.