in this paper, based on equations of lateral vibrations of wires, a non contact method for measuring instantaneous tension in a wire is introduced. the lateral vibration of the string is measured using an eddy current transducer and is sent to a computer. this signal is then imported to suitable software for fast fourier transform (fft) processing. the first natural frequency of the string is c...

We study geodesic motion in expanding spherical impulsive gravitational waves propagating in a Minkowski background. Employing the continuous form of the metric we find and examine a large family of geometrically preferred geodesics. For the special class of axially symmetric spacetimes with the spherical impulse generated by a snapping cosmic string we give a detailed physical interpretation o...

We consider a new 3-parameter class of exact 4-dimensional solutions in closed string theory and solve the corresponding string model, determining the physical spectrum and the partition function. The background fields (4-metric, antisymmetric tensor, two KaluzaKlein vector fields, dilaton and modulus) generically describe axially symmetric stationary rotating (electro)magnetic flux-tube type u...

We study the symmetries of the two dimensional Heterotic string theory by following the approach of Kinnersley et al for the study of stationary axially-symmetric Einstein-Maxwell equations. We identify the finite dimensional symmetries which are the analogues of the groups G and H ′ for the Einstein-Maxwell equations. We also give the constructions for the infinite number of conserved currents...

Vacuum static, axially symmetric space-times in D -dimensional general relativity with a Ricciflat internal space are discussed. It is shown, in particular, that some of the monopole-type solutions are free of curvature singularities and their source can be a disk membrane bounded by a ring with a string or branching type singularity. Another possibility is a wormhole configuration where a part...

In this paper, with the utilization of a transport theorem and three-dimensional version of Leibniz’s rule, the procedure for deriving the time rate of change of an energy functional for axially moving continua is investigated. In the control engineering, the correct solution of the time derivation of an energy functional is essential for designing an effective controller, especially, in the Ly...

Beginning with the stress-energy tensor of an elastic string this paper derives a relativistic string and its form in a parallel transported Fermi frame including its reduction in the Newtonian limit to a Cosserat string. In a Fermi frame gravitational curvature is seen to induce three dominant relative acceleration terms dependent on: position, velocity and position, strain and position, respe...