Analyse des Eisens

Ohne Zusammenfassung     

New lasers and laser schemes

Conclusion We have demonstrated the existence of an anomalous polarization coupling mechanism present in the injection locked TEA CO₂ laser. As a direct consequence of this work, a new injection technique has been formulated which permits efficient injection coupling and maximises energy extraction whilst eliminating the detrimental optical feedback effects to which other injection locking systems are prone.Supported by the Office of Naval Research and the National Science Foundation     

Acceleration noise generated by a random repeated impact process

Acceleration noise levels generated by a random repeated impact process have been predicted and compared with experimental measurements. The process consisted of a ball bouncing on a randomly vibrating surface, and is an idealized representation of random impact phenomena which can occur in machinery and transportation systems where a rolling element is in intermittent contact with the rolling surface. Predictions of the magnitudes of impacts and the times between them have been used in conjunction with established acoustic theory to estimate acceleration noise levels generated by the impacting ball. Measured sound pressure levels were in excellent agreement with the predicted levels.     

Ξ− and Ξ− inclusive production in Ξ− Be interactions at 116 GeV/c

The cross sections for Ξ^? and Ω^? inclusive production in Ξ^? Be collisions at 116 GeV/c have been measured in the kinematic domain [0.1<x _F <0.9, 0<p _T <1.7 GeV/c]. The integrated cross sections per nucleon are found to be about twice as large as in Ξ^? p collisions. The invariant cross sections increase by a factor of 70 for the Ξ^? s and of 100 for the Ω^? s between the central region (x _F ～0.2) and the projectile fragmentation region (x _F ～0.8). In the central region, they have about the same magnitude as the ones for Ξ^? and Ω^? inclusive production inp nucleon collisions. The Ξ^? and Ω^? polarisations have been measured over the same kinematic domain and are found to be compatible with zero.     

Energy constraints in vortex-excited vibrations

Excitation or damping of flow-induced vibrations depends upon the magnitude and the phase relationship between the fluid dynamic force and the oscillatory motion of the body. These have been measured for two aerofoil shapes in mechanically controlled heaving motion in a water channel. At the same time, measurements have been made of the strength and spacing of the associated vortex trails. To help interpret the significance of these measurements, an analysis based upon energy conservation has been performed. When taken together with the classical momentum equation, this yields a relationship giving the energy available for vibration work in terms of three dimensionless vortex trail parameters. Comparing this analysis with the experimental data leads to a qualitative discussion of the significance of the vortex formation mechanism in controlling the excitation or damping of that class of vibrations which is affected by vortex shedding.