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Tehran, Iran

The Iran University of Science and Technology is a research institution and university of engineering and science in Iran, offering both undergraduate and postgraduate studies. Located on Hengam Street in the Narmak neighborhood in northeast Tehran, IUST and its surrounding communities provide a cultural and recreational environment suited to the work of a major research institution. The university consistently ranks among Iran's top three technical universities. Wikipedia.

A new, efficient, one-pot multicomponent reaction for the synthesis of diazepine derivatives in excellent yields is described. The reactions of various 1,2-diamines, terminal alkynes, and an isocyanide take place in the presence of a catalytic amount of magnetically recoverable silica-supported superparamagnetic Fe3O4 nanoparticles in ethanol (as a green reaction medium) at ambient temperature. © 2013 Elsevier Ltd. All rights reserved.

In this research, a new protocol for the one-pot multicomponent synthesis of diazepine derivatives using a 1,2-diamine, a linear or cyclic ketone, and an isocyanide in the presence of a catalytic amount of silica-supported iron oxide (Fe 3O 4/SiO 2) nanoparticles at ambient temperature in excellent yields is described. © 2012 Elsevier Ltd. All rights reserved.

Khaburi D.A.,Iran University of Science and Technology
IEEE Transactions on Instrumentation and Measurement | Year: 2012

In this paper, a new resolver-to-digital conversion method is presented. This method is based on synchronous demodulation of resolver's output signals. A modified angle-tracking observer is proposed to extract the rotor angle in high speeds as well as in low speeds. An estimation algorithm, which is based on the sign and absolute values of sine and cosine of the rotor angle, is introduced to find an appropriate initial value for this observer. This method can be incorporated in a DSP-based motor drive system. The proposed method is simple and cost effective when an appropriate microcontroller is selected for motor control. This method has been successfully implemented in a DSP board. Several tests at different speeds and initial positions have been performed to evaluate the proposed method. © 2012 IEEE.

Samavati V.,Iran University of Science and Technology
Carbohydrate Polymers | Year: 2013

Crude polysaccharide extraction from the Iranian Abelmoschus esculentus was performed using water decoction. Response surface methodology (RSM), based on a five level, four variable central composite rotatable design (CCRD), was employed to obtain the best possible combination of extraction time (X 1: 0.5-6.5 h), extraction temperature (X2: 80-100 °C), number of extraction (X3: 1-5), and water to the raw material ratio (X4: 4-28) for maximum polysaccharide extraction. The experimental data obtained were fitted to a second-order polynomial equation using multiple regression analysis and also analyzed by appropriate statistical methods (ANOVA). The optimum extraction conditions were as follows: extraction time of 4.94 h, extraction temperature of 94.97 °C, number of extraction of 4, and the ratio of water to raw material of 21.74. Under these conditions, the experimental yield was 16.895 ± 0.29%, which is well in close agreement with the value predicted by the model 16.916%. © 2013 Elsevier Ltd.

Rafee Nekoo S.,Iran University of Science and Technology
ISA Transactions | Year: 2013

The state-dependent Riccati equation (SDRE), as a controller, has been introduced and implemented since the 90s. In this article, the other aspects of this controller are declared which shows the capability of this technique. First, a general case which has control nonlinearities and time varying weighting matrix Q is solved with three approaches: exact solution (ES), online control update (OCU) and power series approximation (PSA). The proposed PSA in this paper is able to deal with time varying or state-dependent Q in nonlinear systems. As a result of having the solution of nonlinear systems with complex Q containing constraints, using OCU and proposed PSA, a method is introduced to prevent the collision of an end-effector of a robot and an obstacle which shows the adaptability of the SDRE controller. Two examples to support the idea are presented and conferred. Supplementing constraints to the SDRE via matrix Q, this approach is named a modified SDRE. © 2012 ISA.

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