Hypereutectic aluminum silicon alloys are mainly used in cast form in important components like pistons, cylinder liners, rocker arms, air conditioner compressors, brake drums, engine blocks, etc. These have inherent advantages of being high wear resistance, high strength to weight ratio, high corrosion resistance, good cast performance, high thermal conductivity, good weldability, etc. The inf...

Fundamental understanding of tribochemical wear mechanism of oxide-free single crystalline silicon (without native oxide layer) is essential to optimize the process of ultra-precision surface manufacturing. Here, we report sliding speed-dependent nanowear of oxide-free silicon against SiO2 microspheres in air and in deionized water. When contact pressure is too low to induce Si yield, tribochem...

A novel sliding mode observer for current-based sensorless speed control of induction motors is presented in this paper. The control objective is to guarantee asymptotic tracking of prespecified speed and rotor flux references without mechanical sensors. To this end, an adaptive sliding mode speed and flux observer is introduced: it is based on a different and original approach with respect to ...

We investigate the mechanisms of histone sliding and detachment with a stochastic model that couples thermally induced, passive histone sliding with active motor-driven histone unwrapping. Analysis of a passive loop or twist defect-mediated histone sliding mechanism shows that diffusional sliding is enhanced as larger portions of the DNA is peeled off the histone. The mean times to histone deta...

A new close loop current model flux observer is designed to estimate the rotor flux, position and velocity of an induction machine. The current observer includes carefully designed sliding mode functions which are derivative of the fluxes along the and axes. Therefore, when the estimated current converges to the measured one, the flux estimation is a mere integration of the sliding mode functio...

We study numerically the propagation of an acoustic pulse through a loaded granular material under the hypothesis that the conventional modeling of solid friction used in soft sphere discrete element modeling remains valid at acoustic time scales. As a pulse crosses the material, it temporarily suppresses sliding contacts, making it difficult to prepare states that correspond to experimental co...

A finite element method is used to solve the problem involving thermoelastodynamic instability (TEDI) in frictional sliding systems. The resulting matrix equation contains a complex eigenvalue that represents the exponential growth rate of temperature, displacement, and velocity fields. Compared to the thermoelastic instability (TEI) in which eigenmodes always decay with time when the sliding s...

This paper presents application of parametric techniques (Estimation of signal parameter by rotational invariance techniques (ESPRIT), Root multiple signal classification (Root MUSIC)) for the estimation of harmonics/inter harmonics produced by wind generator under constant, variable rotor speed, load imbalance. Accuracy of estimation by parametric techniques is checked on synthetic signal as w...

This paper presents a speed estimation scheme based on second-order sliding-mode Super Twisting Algorithm (STA) and Model Reference Adaptive System (MRAS) estimation theory for Sensorless control of multiphase induction machine. A stator current observer is designed based on the STA, which is utilized to take the place of the reference voltage model of the standard MRAS algorithm. The observer ...

This paper deals with the Active and Reactive Power control of double-fed induction generator (DFIG) for variable speed wind turbine. For controlling separately the active and the reactive power generated by a DFIG, field oriented control (FOC) and indirect sliding mode control (ISMC) are presented. These non linear controls are compared on the basis of topology, cost, efficiency. The main cont...