A study was carried out to assess primary production and associated export flux in the coastal waters of the western Antarctic Peninsula at an oceanographic time-series site. New, i.e. exportable, primary production in the upper water-column was estimated in two ways; by nutrient deficit measurements, and by primary production rate measurements using separate C-labelled radioisotope and N-label...

Induction motor drives using field oriented control (FOC) for torque and flux control have been used in high performance industrial applications instead of dc motors for many years. In FOC, torque and flux of an induction motor can be controlled independently by decoupling the stator current into its orthogonal components. The FOC method has achieved a quick torque response. But in order to ach...

Geomagnetic field is a one of the candidates for creation of anisotropy in azimuth distribution of extensive air showers over the entered cosmic rays to the atmosphere. Here we present the question: Is there any azimuth anisotropy flux in the upper level of the atmosphere due to the geomagnetic field over the entered cosmic-rays? The obtained answer is: yes. This investigation showed an agreeme...

A major obstacle to using superconducting quantum interference devices (SQUIDs) as qubits is flux noise. We propose that the heretofore mysterious spins producing flux noise could be O_{2} molecules adsorbed on the surface. Using density functional theory calculations, we find that an O_{2} molecule adsorbed on an α-alumina surface has a magnetic moment of ~1.8 μ_{B}. The spin is oriented perpe...

Direct torque control (DTC) of Switched reluctance motor is known to have simple control structure with comparable performance to that of field oriented control techniques. However, the role of optimal selection of the voltage space vector is one of the weakest points in a conventional DTC drive. In this paper optimal selection of voltage space vectors is achieved using neuro fuzzy controller. ...

In this paper we propose a multiobserver switching control strategy for fault tolerant control of induction motors. The strategy combines three current sensors and associated observers that estimate the rotor flux. The estimates provided by the observers are compared at each sampling time by a switching mechanism which selects the sensors–observer pair with the smallest error between the estima...

This paper considers the design of an observer-based adaptive controller for variable speed threephase AC induction motors. The proposed controller allows for the simultaneous and independent control of the speed (torque) and the flux of the motor without requiring the measurement of the flux, and without the knowledge of the rotor resistance and the motor load. The control adaptively estimates...

In this letter, a new sliding-mode sensorless control algorithm is proposed for the field-oriented induction machine drive. In the proposed algorithm, the terms containing flux, speed, and rotor time constant, which are common in both current and flux equations, in the current model of the induction machine are estimated by a sliding function. The flux and speed estimation accuracy is guarantee...