Results of internal friction measurements on the commercial aluminum-magnesium alloys 5052,5086 and 5486 are reported here over the temperature range 50 mK to 300 K, and compared with published data on alloy 5056. Effects of heat treatment and explosive bonds on the internal friction are evaluated. The quality factor of proposed multi-layer aluminum-alloy spherical resonant-mass detectors of gr...

An enhanced dynamic force model of a type of small and soft McKibben-type pneumatic muscle (PM) actuator has been developed. This model takes the factor of external loads and a more sophisticated form of friction into account, and is presented as a polynomial function of pressure, contraction length, contraction velocity and external load. The coefficients in this model are determined from a se...

Drops placed on very hot solids levitate on a cushion of their own vapor, as discovered by Leidenfrost. This confers to these drops a remarkable mobility, which makes problematic their control and manipulation. Here we show how crenelated surfaces can be used to increase the friction of Leidenfrost drops by a factor on the order of 100, making them decelerate and be trapped on centimetric dista...

79 L~ST OF ILLUSTRATIONS 1. Elastic Hysteresis 2. Overdamped Vibration 3. Critically Damped Vibration 4. Underdamped Vibration 5. Optimum Damping Factor for Specified Error 6. Free Gyroscope 7. Inclined Plane 8. Sliding Shoe 9. Kingsbury Thrust :Bearing 10. Circular Pad Air :Bearing 11. Cylindrical Pad 12. Oil-Ring-Bearing 13. Lo\-T Friction Ball :Bearing 14. Low Friction Roller Bearing 15. Sec...

A nonlinear servomotor model with friction, saturation, backlash and motor starting voltage is presented in this paper. Fuzzy control and nonlinear PID control are compared using numerous computer simulations. A systematical method for tuning a PD-type fuzzy controller with training data is introduced. 1.0 Introduction Actual servomotors always have nonlinearities that have to be considered in ...

The performance of an explicit algebraic stress model is assessed in predicting the turbulent ow and forced heat transfer in straight ducts, with square, rectangular, trapezoidal and triangular cross sections, under fully developed conditions over a range of Reynolds numbers. Iso-thermal conditions are imposed on the duct walls, and the turbulent heat uxes are modeled by gradient-di usion type ...

A boundary layer analysis is presented for the mixed convection past a vertical plate in a porous medium saturated with a nanofluid in the presence of variable viscosity effect. The governing partial differential equations are transformed into a set of similar equations and solved numerically by an efficient, implicit, iterative, finite-difference method. A parametric study illustrating the inf...