sensorless speed torque control of induction machines has been widely used in many industrial applications. the simple method of direct vector control can provide tacholess control as well as more complex approaches. in this method, the motor flux can be obtained by measuring voltage and current and integrating motor back electromotive force. the only required motor parameter is stator resistan...

this paper presents a fuzzy search controller approach along with the look-up tables, to optimize the efficiency of a pump-induction motor drive. the induction motor and the converter are modeled based on thermal loss; and for modeling the pump and the hydraulic system, which are non-linear and relatively complicated, the neural network is used. in the designed system, in order to optimize the ...

although, single-sided linear induction motor (slim) utilization has increased in railway applications due to their numerous advantages in comparison to rotational induction motors (rim), there are some sophistication in their mathematical models and electrical drive. this paper focuses on the problems of slim modeling, with assuming end-effect on the basis of field oriented control (foc) as a ...

in direct torque control, the selection of an applied voltage vector is based on the measuredparameters at the beginning of the sampling period. the delay between the measurement and the application of the voltage vector is the origin of an extra torque ripple. in this paper, a new predictive controller is proposed for compensating this delay and reducing the torque ripple. the stator current i...

considering the possibility of the harmful side effects of synthetic antioxidants, it is necessary to substitute the synthetic antioxidants by the natural ones, the antioxidants that have been consumed by man for years. the mango seeds were washed and air dried and the kernels were removed manually from the seeds. mango seed kernel oil was extracted by hexane using soxhlet extraction apparatus....

background and aim: moral psychology studies investigate cognitive and emotional systems involved in moral judgments. this research also examines the effect of emotion manipulation on reaction times to moral dilemmas. method and materials: this was a causal relational study executed on eighty five randomly selected 18-25 year old students from shahid beheshti university. to investigate moral ju...

the antioxidant activities of tbhq, bht and tocopherol mixtures at different concentrations (0, 100, 200, 400 mg/kg) have been evaluated by the application of differential scanning calorimetry (dsc) and rancimat apparatus. rancimat apparatus that measures the secondary oxidation products was set at 110 ⁰c with an air flow of 18-20 l/h to measure the induction period (ip) of the samples. the dsc...

due to the high efficiency and low switching losses of resonant power convertors in comparison with switching convertors, nowadays there is a growing trend towards these convertors. however, because of the high frequency of switching in such convertors, it is quite difficult to present an efficient control method. in this paper, based on the state feedback method and using pole placement techni...

objective: to compare the effectiveness of letrozole and clomiphene citrate (cc) on uterine blood flow rate in patients with unexplained infertility. materials and methods: in this randomized clinical trial 90 women with unexplained infertility referred to a university clinic from january 2011- december 2013 were enrolled. thirty patients were randomized for letrozole, 30 patients for cc and 3o...

both midazolam and thiopental sodium are being used as induction agents and for maintenance of anesthesia. in contrast to other benzodiazepines such as diazepam, midazolam has a rapid onset of action and fast distribution and causes few cardiovascular or respiratory effects. being water soluble, midazolam is also associated with a low incidence of venous irritation. the purpose of this study wa...