BACKGROUND Defining the optimal cutting plane for derotational osteotomy at the distal femur for correction of torsion in cases of patellofemoral instability is still challenging. This preliminary study investigates changes of frontal alignment by a simplified trigonometrical model and demonstrates a surgical guidance technique with the use of femur cadavers. The hypothesis was that regardless ...

The thesis deals with some aspects of conventional, artificial neural network, Fuzzy logic and adaptive network fuzzy inference system (ANFIS) based dual input power system stabilizers for an interconnected power system. A linear dynamic model of a single machine-infinite bus (SMIB) system has been developed in state-space form considering governor, turbine, turbine-generator shaft and excitati...

Cortisol concentrations in hair collected from young male and female adults were assayed and compared for differences along shaft length and between body sites. No significant differences were found between hair shaft sites, supporting a model of the hair shaft as "alive" and responsive to environmental demand in terms of cortisol production. Hair taken from forearms had significantly higher co...

Rotating shafts are important and responsible components of many machines, such as power generation plants, aircraft engines, machine tool spindles, etc. A transverse shaft crack can occur due to cyclic loading, creep, stress corrosion, and other mechanisms to which rotating machines are subjected. If not detected early, the developing shaft crack can lead to a serious machine damage resulting ...

In this paper, dual-rotor counter-rotating (CR) configurations of vertical axis wind turbines (VAWTs) are briefly inspected and divided into three types. This investigation was focused on one these types—the CR-VAWT with co-axial rotors, in which two equal rotors placed the same shaft, displaced from each other along it rotated opposite directions. For three-blade H-Darrieus properties design t...

An accurate average value model of synchronous machine-rectifier system considering the effect of stator resistance is derived in this paper. A proper voltage-behind-reactance synchronous machine model without any approximations is used for the generator that allows effective calculation of commutation displacement angle. All rectification modes of the rectifier are studied. A detailed switchin...

In this paper, the behavior of a doubly fed induction generator (DFIG) is proposed under an unbalanced grid voltage and without using a rotor position sensor. There are two main methods that have been used for the detection of rotor position: use of a shaft sensor and use of a sensorless algorithm. In this paper the shaft sensor is eliminated and a position sensorless algorithm is used for esti...

Considering backlash, time-varying mesh stiffness and radial clearance of bearing, nonlinear dynamic model of gear bearing flexible shaft system is established taking into account breathing crack in shaft and tooth wear. Nonlinear dynamic equations are solved by Runge-Kutta method. Effect of backlash, crack in shaft and tooth wear faults on the nonlinear dynamic behavior of gear-shaft-bearing s...