Abstract: A method and apparatus for measuring the mass of a dynamic load without being influenced by vibration caused by the apparatus itself or the environment. A dynamic load sensor that supports the dynamic load is periodically and continuously reciprocated in at least one predetermined direction. Within the dynamic load sensor, one end of a member comprising a spring system is fixed to a base of a non-spring system, the other end of the spring system is free. A load is applied to the free end of the spring system. The base is continuously and periodically agitated along with the spring system. A displacement of the base y.sub.1 and a displacement y.sub.2 of the free end of the spring mass system are continuously measured. By obtaining the first-order derivatives y.sub.1 and y.sub.2 and the second-order derivatives y.sub.1 and y.sub.2 from said displacements y, and y.sub.2 with respect to time, the mass of the load, m, can be calculated by the equation:m?y!=mg-?(mg+kf.sub.2 (y-y.sub.1 +y.sub.2))-f.sub.3 (y-y.sub.

Abstract: A method and apparatus for measuring a load under a dynamic state where variations such as swinging and vibration exist. One of the ends of a member constituting a spring system is fixed with the other end free. A stationary load We is calculated in accordance with equation ##EQU1## by attaching a load to the free end and measuring the instantaneous displacement Yi. In the above equation, Wi is the instantaneous load, g is gravitational acceleration, g.sub.(A/L)i is the acceleration of the free end obtained by differentiating twice the displacement Yi, and k is a spring constant. When a base to which the member constituting the spring system is fixed undergoes variations such as swinging and vibration the stationary load We is determined by ##EQU2## where g.sub.(G/L)i is the acceleration of variation of the base.

Abstract: A ship has an electromagnetic thrust generator including a cylindrical magnet in which there is arranged a helical duct for conducting sea water. The magnet includes a coil housing in which a superconducting coil is disposed. The duct includes an outer wall disposed opposite the internal surface of the coil housing. Electrode members are mounted on inner and outer walls of the duct to create an electrical field across the duct.

Abstract: A thrust generator including a superconducting solenoid magnet 1, a thrust duct 2 and a power supply device 3. The spiral portion of the thrust duct 2 is inserted in the hollow interior of the superconducting solenoid magnet 1. Anode 8 and cathode 9 are fixed at both inner walls of the thrust duct 2. Electric power is supplied to an electromagnetic fluid 10 in the duct 2 to produce a magnetic field and a Lorentz's force f. The electromagnetic fluid 10 flows into the thrust duct 2 through an opening 6a at the inlet end portion 6 where it is urged continuously by the Lorentz's force F and jetted outside from an opening 7a at the outlet end portion 7. The reaction of the jet force becomes a thrust. A Lorentz's force f, generated by the superconducting solenoid magnet 1 and by the current J flowing through each current feed element, rotates and drives the thrust duct 2.

Abstract: A superconductor for magnetic field shielding which is characterized in that it includes at least one composite lamination including a thin film of the superconductor and a metal layer laminated with the thin film of the superconductor having a thickness not more than that obtained at the turning point where the magnetic field shielding effect of a single film of the superconductor changes from an abrupt increase to a gradual increase as the thickness of the superconductor film increases. This superconductor for magnetic field shielding has an extremely great magnetic field shielding effect even though the superconductor is in thin layers.