− A new controlled-clearance pressure balance has been developed to improve the hydraulic pressure standard for pressures up to 1 GPa. For several controlledclearance piston-cylinders, characterization experiments based on the Heydemann-Welch model were performed to estimate the effective area of them. The results for the piston-cylinders of different pressure ranges are exemplified in this pap...

We consider a massive inelastic piston, whose opposite faces have different coefficients of restitution, moving under the action of an infinitely dilute gas of hard disks maintained at a fixed temperature. The dynamics of the piston is Markovian and obeys a continuous Master Equation: however, the asymmetry of restitution coefficients induces a violation of detailed balance and a net drift of t...

The piston shock problem is a classical result of shock wave theory. In this work, the analogous dispersive shock wave (DSW) problem for a fluid described by the nonlinear Schrödinger equation is analyzed. Asymptotic solutions are calculated for a piston (step potential) moving with uniform speed into a dispersive fluid at rest. In contrast to the classical case, there is a bifurcation of shock...

A dynamic model of a free liquid piston that exploits piston geometry to produce a high inertance was developed for use in a free piston engine compressor. It is shown that for the size scale targeted, advantageous piston dynamics can be achieved with a reduced piston mass compared to a rigid piston design. It is also shown that the viscous losses associated with the liquid piston are negligibl...

Pressure and performance requirements of axial piston pumps and the proportion of churning losses in axial piston pumps increase significantly with increasing speed. To investigate the primary distribution of churning losses in axial piston pumps at various ranges of speed, a test rig was set up in which other friction losses can be eliminated, thus making it possible to investigate the net chu...

We calculate the scalar Casimir energy and Casimir force for a R×N Kaluza-Klein piston setup in which the extra dimensional space N contains a non-commutative 2sphere, SFZ . The cases to be studied are T d × SFZ and SFZ respectively as extra dimensional spaces, with T d the d dimensional commutative torus. The validity of the results and the regularization that the piston setup offers are exami...

Friction-related failures are a frequent cause of catastrophic damage in mechanical systems, resulting significant repair expenses and/or production delays industry worldwide. Scuffing is one the most concerning friction-related mechanisms. It characterized by an abrupt failure mechanism, which makes its prediction unresolved today. Therefore, any situ and real-time monitoring system such great...

This paper shows the mixed lubrication analysis between the vane tip and rolling piston in a rotary refrigerant compressor, coupling the motion equations of vane and rolling piston, the elastohydrodynamic lubrication (EHL) analysis of line contact and the equations of viscosity characteristics of lubricating oil as a function of oil pressure, oil temperature and concentration of refrigerant. Th...

OBJECTIVE To evaluate the effect of piston diameter in primary stapedotomy for otosclerosis patients measured by hearing outcome. DATA SOURCES PubMed, Embase, and the Cochrane Library. REVIEW METHODS A systematic search was conducted. Studies reporting original data on the effect of piston diameter on pure-tone audiometric results in patients undergoing primary stapedotomy for otosclerosis ...

We provide a completely new perspective for the analysis of Casimir forces in very general piston configurations. To this end, in order to be self-contained, we prove a “gluing formula” well known in mathematics and relate it with Casimir forces in piston configurations. At the center of our description is the Dirichlet-to-Neumann operator, which encodes all the information about those forces. ...