This paper investigates the applicability to sperm whales of the theory of sound radiating from a piston. The theory is applied to a physical model and to a series of sperm whale clicks. Results show that wave forms of off-axis signals can be reproduced by convolving an on-axis signal with the spatial impulse response of a piston. The angle of a recorded click can be estimated as the angle prod...

A closed macroscopic equation for the motion of the two-dimensional adiabatic piston is derived from standard hydrodynamics. It predicts a damped oscillatory motion of the piston towards a final rest position, which depends on the initial state. In the limit of large piston mass, the solution of this equation is in quantitative agreement with the results obtained from both hard disk molecular d...

It was decided at SLAC to use removable liners mechanically mounted to the chamber walls and the piston. This would allow faster replacement of the pre-fabricated units, should the Scotchlite be damaged, without the need to chisel the remains of the material from chamber walls. The problems of eddy current heating of the piston further required that the piston liner be an insulator. It seemed n...

We study a heavy piston that separates finitely many ideal gas particles moving inside a one-dimensional gas chamber. Using averaging techniques, we prove precise rates of convergence of the actual motions of the piston to its averaged behavior. The convergence is uniform over all initial conditions in a compact set. The results extend earlier work by Sinai and Neishtadt, who determined that th...

This paper proposes a novel method to test the dynamic damping characteristics of valve. The testing system employs the vertical movement pattern, and has a suspension support structure. Force sensors are installed to measure the dynamic friction of the working valve directly. Making use of LuGre friction model and both adaptive genetic algorithm and chaos particle swarm optimization algorithm,...

In optimal trajectory control, one formulates an optimization problem in which one is interested in minimizing a certain criteria like, say, energy used per unit distance travelled subject to various constraints like say walking speed, no foot scuffing, respecting actuator bounds and so forth. The optimal trajectory problem is then cast into a parameter optimization by, e.g., finding control to...

The Stirling cycle and related terminology is defined. Selected contemporary research involving the cycle in environmentally friendly applications is cited. Three conventional engine configurations that utilize a reciprocating power piston and crank shaft (the Alpha, Beta, and Gamma) are characterized, in terms of minimum number of components, advantages, and disadvantages. A new type of Stirli...