Showing papers on "Rotation published in 1978"

Tidal friction and the Earth's rotation.

Abstract: Historical Background and Introduction.- References.- Pre-Telescopic Astronomical Observations.- 1. Introduction.- 2. Historical Development.- 3. Inter-Relation of Parameters.- 4. Recent Investigations.- 5. Remarks on the Selection of Suitable Observations.- 6. Observations of Total and Near-Total Solar Eclipses.- 7. Method of Analysis.- 8. Geophysical Discussion.- 9. Conclusions.- References.- Tidal Deceleration of the Earth's Rotation Deduced from Astronomical bservations in the Period A.D. 1600 to the Present.- 1. Introduction and Principle of Method.- 2. Moon's Orbital Angular Deceleration.- 2.1 Deceleration with Respect to Dynamical Time.- 2.2 Deceleration with Respect to Atomic Time.- 3. Tidal Deceleration of Earth's Rotation.- 4. Conclusions.- References.- Determination of the Rotation of the Earth (at Present).- 1. Introduction.- 1.1 Preview.- 2. General Features of the Rotation of the Earth.- 2.1 Variation in the Earth's Rate of Rotation.- 2.2 Polar Motion.- 3. Equatorial System.- 4. Astronomic Longitude and Latitude.- 5. Time Scales.- 5.1 Astronomic Time.- 5.2 Atomic Time.- 6. Methods and Instruments of Observation.- 6.1 Optical Instruments.- 6.2 Doppler Satellite Measurements.- 7. Data Analysis Centers.- 8. Results on the Rotation of the Earth.- References.- Effect of Tidal Friction on the Lunar Orbit and the Rotation of Earth and Its Determination by Laser Ranging.- 1. Introduction.- 2. The Physical Problem.- 3. The Laser Technique and Its Application.- 4. Determination of the Lunar Acceleration.- 5. Comparisons and Difficulties of Interpretation.- References.- Appendix A: Comments on the Perturbed Mean Motion 52 ppendix B: Reality of the Venus Effect 53 ides of the Solid Earth from Gravimetric Measurements.- 1. Introduction.- 2. Basic Concepts.- 3. The Tidal Potential.- 4. Determination of LOVE numbers from Gravimetric Data.- 5. Instrumentation.- 6. Actual Problems.- 7. Recent Results.- 8. Future Activities.- References.- Tidal Friction in the Solid Earth: Loading Tides Versus Body Tides.- 1. Introduction.- 2. Dissipated Tidal Energy in the Solid Earth.- 2.1 Theory of Dissipation in a Heterogeneous Incompressible Earth.- 2.2 Dissipation of Body Tide Energy.- 2.3 Dissipation of Loading Tide Energy.- 3. Global Tidal Q and Tidal Phase Shifts.- 3.1 Loading Tide Q Versus Body Tide Q.- 3.2 Numerical Results for the Body Tide.- 3.3 Theoretical Relationship between Tidal Bulge Angles, Body Tide Phase Shifts, and the Global Body Tide Q.- 3.4 Some More Numerical Examples.- 3.5 Numerical Results for the Loading Tides.- 4. Conclusions.- References.- Tidal Dissipation in the Oceans.- References.- The Influence of Solid Earth Deformations on Semidiurnal and iurnal Oceanic Tides.- 1. Introduction.- 2. Considering Tidal Loading and Ocean Self-Attraction in.- Ocean-Tide Models.- 2.1 Tidal Integrodifferential Equations and the Energy-Equation Belonging to Them.- 2.2 Properties of Different Ocean-Tide Models.- 3. Generalization of the 4 -Primitive-Equations Model.- 3.1 The Finite-Difference Scheme.- 3.2 Oceanic Tides on a Nonrotating Earth.- 4. The Computed Global M2-Tide.- 5. The Computed Global K1-Tide.- 6. Conclusions.- Glossary of Symbols.- References.- The Numerical Computation of Tidal Friction for Present and ncient Oceans.- 1. Introduction.- 2. Computation of Tidal Friction by Hydrodynamic-Numerical.- Models.- 2.1 Basic Equations.- 2.2 Analytic Considerations.- 2.3 Hydrodynamic-Numerical Models.- 3. A Numerical Model for the Present Ocean.- 3.1 Requirements.- 3.2 Balance of Angular Momentum.- 4. Numerical Model for Ancient Oceans.- 4.1 Necessity of Such a Model.- 4.2 Bathymetry.- 4.3 Application to the Permian Ocean.- 4.4 Verification.- 5. Further Activities.- References.- The Earth's Palaeorotation.- 1. The Coral Data.- 2. The Bivalve Data.- 3. Stromatolite Data.- 4. Combined Data 1.- References.- Periodic Growth Features in Fossil Organisms and the Lenght of the ay and Month.- 1. Introduction.- 2. Biological Considerations.- 2.1 Growth Increments in Corals.- 2.2 Growth Increments in Bivalves.- 2.3 Growth Increments in Stromatolites.- 2.4 Biological Clocks.- 3. The Data.- 3.1 Recording the Data.- 3.2 The Published Data.- 4. Implications of the Growth Increment Data.- 5. Conclusions.- References.- Geological and Geophysical Evidence Relating to Continental rowth and Dynamics and the Hydrosphere in Precambrian Times: Review and Analysis.- 1. Introduction.- 2. The Hydrosphere.- 3. The Continental Crust.- 4. Precambrian Dynamics of the Continental Crust.- 5. Palaeomagnetic Analysis of Precambrian Crustal Movements.- 5.1 Gondwanaland-Late Precambrian and Lower Palaeozoic.- 5.2 Laurentian Shield-Upper Proterozoic.- 5.3 African Shield-Upper Proterozoic.- 5.4 Laurentian Shield-Middle-Lower Proterozoic.- 5.5 Africa-Middle-Lower Proterozoic.- 5.6 Australia-2600-1100 my.- 5.7 Baltic-Ukrainian Shield-2000-1200 my.- 6. Palaeomagnetic Correlations Between the Proterozoic Shields.- 7. Proterozoic Supercontinent.- 8. Age of the Earth-Moon System.- 9. Stromatolite Evidence for Precambrian Tidal Parameters.- 10. Sedimentologic Evidence for Precambrian Tidal Parameters.- 11. The Tidal Couple and Changes in the Earth's Rotation in Precambrian Times.- References.- Concluding Remarks.

Vector measuring current meter

Abstract: The present meter is characterized by its very accurate cosine response tourrent vector components of fluid (air or water) velocity parallel to the rotational axes of its propeller-like flow sensors. Structurally, it employs two flow sensors rotatably mounted on a rod or `sting` carried by a casing. Each sensor includes a pair of back-to-back propellers or fans mounted on a single axial shaft rotatably supported by the rod. The rotational axes of the two flow sensors are normal one to the other and also normal to the axis of the rod. Rotation of the fans activates a switch-like arrangement electrically coupled to an up-down counter carried in the casing. Blade rotation in one direction yields an `up` count and vice versa.

Compliant assembly system device

Abstract: A compliant assembly system device including operator means for holding parts to be assembled; first and second interconnected deformable structures for supporting the operator means; the first deformable structure including a deformable portion having a first center being responsive to a force and to a moment applied to the operator means to permit rotation of the operator means about the first center; the second deformable structure including a deformable portion having a second center spaced from the first center and remote from the system, being responsive to a force and to a moment applied to the operator means to permit rotation of the operator means about the second remote center; the force causing generally equal and opposite offsetting rotations about the first and second centers which result in translational motion of the assembly device and a moment causing generally equal and opposite offsetting translations which result in rotation of the assembly device about an intermediate compliance center between the first and second centers at or near the parts to be assembled.

Phase nulling optical gyro

Abstract: A beam of light is split and introduced into different ends of a light path whose rotation is to be sensed. At least one frequency shifter is placed in the light path to affect the frequency difference of the two beams so as to introduce or adjust a nonreciprocal phase shift. The beams are then mixed back together and the resultant beam is detected and analyzed by suitable circuitry to provide an output indicative of rotation of the light path.

Venus' rotation and atmospheric tides

Abstract: VENUS rotates with a period of 243.00 ± 0.04 d retrograde. The obliquity, or angle between the spin vector and orbit vector is 178 ± 1° (ref. 1). Both the long period and the near 180° obliquity suggest that the spin has evolved under the influence of tidal torques. Tides raised by the Sun in the body of Venus would de-spin the planet in ~10^8 yr if no other torques were acting. The final state would be one of synchronous rotation (one side always facing the Sun). So either we are living during the final stages of Venus' tidal evolution, an unlikely circumstance, or else Venus has already reached a stable equilibrium in which other influences balance the solar body tide. It is possible that the Earth has ‘captured’ Venus into a resonance in which the spin period is 243.165 d. However, for this resonance to be a stable equilibrium, either Venus must have a gravitational field that is ~10 times ‘rougher’ than the Earth's, a possibility that is largely ruled out by direct observation, or a third torque must balance the body torque due to the Sun. Tides in the atmosphere driven by periodic solar heating could supply the necessary third torque, but no quantitative theory has previously been published. Such a theory is presented here, in which we argue that the current rotation is a stable balance between atmospheric and solar body tides.

Shower spray heads

Abstract: A shower spray head for providing a fluid spray with mechanical vibration of a part of the spray head, comprises, in combination, a fluid flow for delivering a shower spray; a turbine mounted in the path and drivable in rotation about an axis by fluid flow through the path; an eccentric rotatable form mounted for rotation about the axis and drivable by the turbine and eccentrically mounted with respect to the axis; and a vibratory housing connected by a pivotal connection to the eccentric form whereby rotation of the turbine during use causes vibration of the vibratory housing.

Vortices in magnetospheric plasma flow

Abstract: Vortical motion in the early morning sector of the plasma sheet was detected by means of two-dimensional and three-dimensional plasma measurements obtained by the LASL/MPI analyzers on the ISEE 1 and 2 satellites. The vortices, when present, are manifested as a recurrent or continuing rotation of the bulk flow vector in a plane sometimes moderately inclined with respect to the ecliptic plane. The preferred sense of the rotation is clockwise when viewed from above the ecliptic plane. The vortex rotation period ranges from 5 to 20 min., and several rotations can occur in a relatively uninterrupted sequence. The plasma vortices are estimated to be several earth radii in size. The possibility of a 'vortex street' convecting earthward along the axis of the magnetotail is considered.

Child's safety seat for vehicles

Abstract: A safety seat has a frame with interconnecting legs intermediate structure and back structure. Securing means such as hooks are associated with the frame to removably mount the frame to a vehicle passenger seat. A seat proportioned to accommodate a child is positionable within the frame. The seat is mounted to the frame by rotation means adapted to the intermediate structure so that the center of gravity of the seat with the child residing therein is below the pivot means. Deceleration means such as a hydraulic cylinder is secured to the seat by attachment means extending below the seat and the center of gravity and to the back structure. Upon application of external forces the seat tends to rotate about the rotation means. The deceleration means acts to retard rotation of the seat about the rotation means.

Portable wrapping film dispenser

Abstract: A hand-held device for dispensing plastic film for wrapping stacked items including a hand-actuated braking mechanism to permit the holder to stretch the film as he winds it around a stack. The braking mechanism is actuated by rotation of one of the handles so that the stability of the roll is not affected during tensioning and wrapping.

Flow between a stationary and a rotating disk with suction

Abstract: The equations for the viscous flow between two coaxial infinite disks, one stationary and the other rotating, are solved numerically. The effects of applying a uniform suction through the rotating disk are determined. Initially, the fluid and disks are at rest. The angular velocity of one disk and the amount of suction through it are gradually increased to specific values and then held constant. At large Reynolds numbers R, the equilibrium flow approaches an asymptotic state in which thin boundary layers exist near both disks and an interior core rotates with nearly constant angular velocity. We present graphs of the equilibrium flow functions for R = 104 and various values of the suction parameter a (0 ≤ a ≤ 2). When a = 0, the core rotation rate ωc is 0·3131 times that of the disk. Fluid near the rotating disk is thrown centrifugally outwards. As a increases, ωc increases and the centrifugal outflow decreases. When a > 1·3494, the core rotation rate exceeds that of the disk and the radial flow near the rotating disk is directed inwards. We also present accurate tabular results for two flows of special interest: (i) the flow between a stationary and a rotating disk with no suction (a = 0) and (ii) Bodewadt flow. The latter can be obtained by suitable scaling of the boundary-layer solution near the stationary disk for any a ≥ 0. Since several solutions to the steady-state equations of motion have been reported, the question arises as to whether other solutions to the time-dependent equations of motion with zero initial conditions can be found. We exhibit a rotational start-up scheme which leads to an equilibrium solution in which the interior fluid rotates in a direction opposite to that of the disk.

Vertical axis wind turbine

Abstract: An improved type of wind turbine comprising a rotating assembly attached to a central hub, which is supported for rotation in a horizontal plane about a vertical axis, in a bearing on top of a tower of selected elevation The rotating assembly comprises at least two radial spokes or arms positioned from each other at equal angles in a horizontal plane The outer ends of the arms are attached to a connector assembly which generally is in the form of a U-shaped member lying in a vertical plane A long thin vertically oriented airfoil is mounted on the ends of each connector, the plane of the chord of the airfoil is perpendicular to the axis of the arm which supports it A torque shaft is attached at the axis of the hub and passes axially downwardly through the tower to an energy conversion device mounted in a housing on the base, which supports the tower The tower may be guyed by means of cables, etc which are attached below the level of the rotating assembly Means are provided for using wind power to bring the rotating assembly up to a selected operating speed Braking vanes are provided to limit the top speed of rotation of the assembly

Equipment for the detection of rotation parameters in particular for a wheel-velocity sensor

Abstract: A wheel velocity sensor of the type having a toothed rotor and a stator with a detecting head mounted adjacent the rotor in proximity with the rotor teeth. The rotor is assembled with the bearing seal in the wheel hub as an integrated unit, being encased within a cavity formed in the seal to receive the rotor. The detecting head of the stator contacts the face of the seal, which is coated with a low friction material, so that a constant gap is maintained between the detecting head and rotor during rotation of the wheel to obtain more accurate wheel velocity signals.

Visible and infrared polarization ratio spectroreflectometer

Abstract: The instrument disclosed assists in determining the refractive index and absorption index, at different spectral frequencies, of a solid sample by illuminating the sample at various angles in incidence and measuring the corresponding reflected intensities at various spectral frequencies and polarization angles. The ratio of the intensity of the reflected light for parallel polarized light to that for perpendicular polarized light at two different angles of incidence can be used to determine the optical constants of the sample. The invention involves an apparatus for facilitating the utilization of a wide variety of angles of incidence. The light source and polarizing element are positioned on an outer platform; the sample is positioned on an inner platform. The two platforms rotate about a common axis and cooperate in their rotation such that the sample is rotated one degree for every two degrees of rotation of the light source. This maintains the impingement of the reflected light upon the detector for any angle of incidence without moving or adjusting the detector which allows a continuous change in the angle of incidence.

Bearing with bearing cage

Abstract: An annular cage for the rollers of a bearing is located in the annular space between two bearing races and is normally spaced from both races when concentric. The cage is so constructed that, when unbalanced forces on the cage during rotation in the bearing tend to move the cage from its concentric position into contact with a piloting surface, hydrodynamic forces are developed which act to keep the cage out of contact with that surface.

Internal refractor focusing solar energy collector apparatus and method

Abstract: A solar energy collector apparatus and method, the apparatus including an open-top shell-like structure. A Fresnel lens system and a mirror system inside the shell structure focus and direct solar energy toward a solar energy absorber apparatus also inside the shell structure. The shell structure is mounted upon a hollow axle in a framework for rotation about its longitudinal axis. The framework supports the longitudinal axis in a position generally parallel to the axis of rotation of the earth to provide an equatorial mounting for the solar energy collector. Rotation about the longitudinal axis adapts the solar collector for following the east-west movement of the sun. The optical apparatus in the shell structure is adapted for movement to follow the north-south seasonal changes in the sun's position. The solar energy absorber apparatus is nonrotatably supported inside the shell structure by the hollow axle and heat transfer conduits pass through the hollow axle to the solar energy absorber apparatus in nonrotable relationship therewith. A photovoltaic apparatus may be included within the shell structure for converting at least a portion of the incoming solar spectrum to electrical energy. This combination of features provides higher solar efficiencies and higher temperatures in the heat transfer fluid. The method includes tracking the sun with the solar energy collector apparatus thereby maximizing the amount of solar energy collected while eliminating coupling failures in the heat transfer conduits.

Secure bottle with novel cap

Abstract: A secure bottle for storing of pills, or the like, wherein the novel cap member comprises a rotatable member and a stationary member positioned for relative rotation with one another; the rotation being opposed by a biasing means between said members; and the rotation also being opposed by a locking construction engaging the member until the upper member is lifted free thereof.

Mapping apparatus employing two input axis gyroscopic means

Abstract: Mapping apparatus comprises: (a) a gyroscope and a carrier frame therefor, (b) the gyroscope characterized as having a spinning rotor and torsion structure defining a gimbal, and wherein the rotor spin frequency has a predetermined relation to a resonant frequency of said structure, (c) the gyroscope further characterized as having two input axes, and an output axis about which the spin rotor rotates, (d) drive means operatively connected with said frame to rotate the frame about one of said axis, and (e) the gyroscope having means to detect rotor pivoting about one of said two input axes in response to said rotation of the frame. A second gyroscope may be employed, with its frame. rotated by the same drive means; and the output axes of the two gyroscopes are typically orthogonally related.

Golf swing muscle developer

Abstract: This invention consists of a rotatable pulley or reel attached to an inverted U-shaped mounting bracket, with a flexible cord attached to and wound around the pulley or reel, whose rotation is retarded or resisted by the strong force or tension of a coiled spring or elastic cord, with a handle of wood or other material attached to the other end of the flexible cord so that when the inverted U-shaped mounting bracket is hooked or fitted in place over the horizontal top of a door or other appropriate support the handle may be pulled downward and away from the pulley or reel in a simulated golf stroke downswing to unwind the flexible cord as it rotates the pulley or reel against the strong force or tension of the retarding or resisting coiled spring or elastic cord that is connected to the pulley or reel. By making many repeated downswings against the strong force of the resistance to the rotation of the pulley or reel all muscles used in driving a golf ball are strained and strengthened, enabling the golfer to drive a golf ball farther when playing on a golf course.

Self-contained solar tracking device

Abstract: A trough type solar collector or other body is mounted to rotate about a generally north-south pivotal axis. A balance weight is supported on an elongated heat sensitive beam anchored at its ends to the westerly side of the collector. The beam is adapted to bow away from the collector when it is heated by the sun's rays, thereby causing the balance weight to exert westward rotational force on the collector. A reflector may be positioned behind the beam to concentrate the sun's rays on the beam. A shutter is fixed to the collector to shade the beam when the collector is pointing toward the sun. Biasing means, such as a fixed weight secured to the easterly side of the collector, oppose the torque exerted by the balance weight and urge the collector to rotate eastwardly when the beam is unbowed. Damping means control the speed of westward and eastward rotation of the collector, and a pair of stops limit its westward and eastward travel. Alternative forms of heat sensitive support means for the balance weight and biasing means are shown and described. The motion of the solar tracking body can be utilized to control the orientation of other structures, such as adjustable louvres, with respect to the diurnal motion of the sun.

Roll sheet dispenser

Abstract: A sheet material dispensing apparatus wherein the sheet passes through a nip formed by a drive roller and a pressure roller. A lever is mounted for rotation about a first point and a gear segment is mounted for rotation about a second point. When the lever is rotated, a point or surface on the lever slidingly contacts a point or surface on the gear segment causing the gear segment to rotate through a greater angle than the lever. The teeth of the gear segment are operably engaged with gear means which causes rotation of the drive roller. In another aspect of the invention, the gear means for rotating the drive roller includes a floating gear mounted in a slot that is aligned generally parallel to the teeth of the gear segment and which causes rotation of the drive roller during one direction of travel of the gear segment and is disengaged from the drive roller during the other direction of travel of the lever. The invention also employs an overload mechanism which prevents excessive force from being applied to the gears in the event the dispenser becomes jammed.

A rotation shearing interferometer with phase-compensated roof-prisms

Abstract: The variation with rotation angle, of the fringe visibility at the output of a rotation shearing interferometer illuminated with unpolarised light, is investigated both theoretically and experimentally. It is shown that highly contrasted fringes can be obtained for any rotation angle, by cementing an appropriate phase plate to the entrance face of each roof-prism. Neither a polarizer nor an analyzer is necessary. The method can be applied to any interferometer using roof-prisms.

Hemispherical collector of direct dispersed and reflected waves

Abstract: A collector of waves, such as of solar radiations entering from any direction, concentrates them upon a receiver that converts them to useful purposes. Moderate concentration factors are achieved without the necessity of tracking the sun. The reflective surface of the collector is a semicircular arc developed by rotation about an axis either in the plane of the arc passing through the center of curvature to form a hemisphere, or in the panel of the arc and tangent to one end to form a hemitoroid with a central cusp, or about some other axis; or some combination of these shapes. The device is compounded to provide an increased concentration factor. Means are taught for adapting the device to heat-collecting plates, heat pipes, or photovoltaic conversion devices (solar cells) of either disc, ribbon, or tube construction and for installing the device on surfaces of buildings with or without the capability of tracking the sun.

Vibrator with eccentric weights

Abstract: Two eccentric weights of a vibrator are mounted, respectively, on two coaxial shafts, one of which is a hollow shaft mounted on the other shaft The two shafts can be connected for rotation in unison, and can be separated for relative rotation to alter the angular relationship between the weights The mechanism is provided to alter the angular relationship between the weights while both shafts continue to rotate An electric clutch is connected between the driven shaft and the hollow shaft to connect the two coaxial shafts for rotation in unison, and a brake is provided to slow the rotation of the hollow shaft after the clutch is disengaged Thus, the angular relationship between the eccentric weights, and hence the stroke of the vibrator, can be changed