Apparatus and method for reducing thermal stress in a turbine rotor

A gas turbine is described wherein the thermal stresses in the turbine rotor are reduced. The rotor includes a central disc with a peripheral rim, and a plurality of blades extending radially outward from the rim. To reduce thermal stresses, a duct arrangement is provided which selectively directs hot gases from the turbine combustor to the rim during the turbine start up. The hot gases from the combustor serve to heat the rim, and decrease the start up period necessary to bring the temperature profile of the rotor into the operating temperature range. After the start up period, the duct arrangement is then used to direct cool gases from the turbine compressor to the rim of the rotor in order to maintain a lower rotor equilibrium temperature

Screening Masses and Improvement in Pure SU(2) Lattice Gauge Theory at High Temperatures

From the long-distance behaviour of gluon and Polyakov loop correlation functions we extract masses resp. energies in the electric and magnetic sectors. We discuss their dependence on the temperature and on the momentum as well as the relevance of an improvement of the lattice discretization of the action.Comment: Talk presented at LATTICE97 (Finite Temperature and Density) by J. Rank, 3 pages, LaTeX File, espcrc2.sty Style File and 2 eps figures include

A comparative study of 1959-60 referrals to the school adjustment counselling services of Malden and Needham

Thesis (M.S.)--Boston Universit

Quantum Flux and Reverse Engineering of Quantum Wavefunctions

An interpretation of the probability flux is given, based on a derivation of its eigenstates and relating them to coherent state projections on a quantum wavefunction. An extended definition of the flux operator is obtained using coherent states. We present a "processed Husimi" representation, which makes decisions using many Husimi projections at each location. The processed Husimi representation reverse engineers or deconstructs the wavefunction, yielding the underlying classical ray structure. Our approach makes possible interpreting the dynamics of systems where the probability flux is uniformly zero or strongly misleading. The new technique is demonstrated by the calculation of particle flow maps of the classical dynamics underlying a quantum wavefunction.Comment: Accepted to EP

Real trajectories in the semiclassical coherent state propagator

The semiclassical approximation to the coherent state propagator requires complex classical trajectories in order to satisfy the associated boundary conditions, but finding these trajectories in practice is a difficult task that may compromise the applicability of the approximation. In this work several approximations to the coherent state propagator are derived that make use only of real trajectories, which are easier to handle and have a more direct physical interpretation. It is verified in a particular example that these real trajectories approximations may have excellent accuracy.Comment: 19 pages, 6 figure