In the paper the principle and performances of the pulsating current injection based sensorless control of permanent magnet synchronous motor (PMSM) are analyzed theoretically and investigated by simulations. In the analyses, the effects of the speed EMF terms and the deviation between the actual d-axis high-frequency current and the command, which results from the limited gain and bandwidth of...

This paper presents the motion characteristics for high-speed catamarans travelling in waves. Two mathematical models, threedimensional translating-pulsating source distribution technique and three-dimensional pulsating source distribution technique, are used for predicting the motions of the wave-piercing catamaran in oblique waves. The comparison between numerical predictions and experimental...

In their recent topical review, Nabavi and Siddiqui (Meas. Sci. Technol. 2010 21 042002) recommended the use of hot-wire anemometry for velocity measurements in pulsating flows, especially at high frequency. This recommendation is misleading. The procedures invoked by these authors are valid only for small-amplitude fluctuations, which are of little interest for pulsating flows. When large-ampl...

the applications of electrochemical machining are increasing because of increasing requests of industries for materials with high strengh and high hardness. regular ecm uses a tool with spicified profile shape that is similar to final shape of workpiece. in this reasearch a nozzle that delivers electrolyte to the machining gap is used for machining cylinderical workpieces. by moving the electro...

We describe flight variability in the woodwasp Sirex noctilio Fabricius, 1793 (Hymenoptera: Siricidae) by studying tethered females in a flight mill device and analyzing output data by a time series methodology. Twenty-eight wasps were flown during 24 h-long periods, under controlled temperature and lighting conditions. The maximum distance recorded was 49 km, and mean velocity was 0.37 m s(-1)...

The processes of dehydration and granulation are associated with the heat transfer to solid particles from gas coolant, which acts as a fluidizing agent causes stochastic movement granular material in apparatus. To implement layered structure mechanism organic-mineral fertilizers it is necessary ensure intensive circulation gradual passage through appropriate technological zones main problem lo...