Time filter

Source Type

Mohammadpour H.,Islamic Azad University | Moghimipour E.,Ahvaz Jundishapur University of Medical Sciences | Rasooli I.,Shahed University | Fakoor M.H.,Islamic Azad University | And 4 more authors.
Jundishapur Journal of Natural Pharmaceutical Products | Year: 2012

Background: Aflatoxin B1 (AFB1) is a highly toxic and hepatocarcinogenic metabolite produced by Aspergillus species. Some natural products are known to kill fungi and destroy toxins and toxin-producing agents. Objectives: The purpose of this study is to provide experimental data on the antifungal activity of cumin oils and their components that could be considered suitable for application in foods and drugs. Materials and Methods: The essential oil (EO) of Cuminum cyminum L. collected from Alborz Mountain, Iran, was obtained by hydro-distillation. The oil was analyzed by gas chromatography (GC) and chromatography/mass spectrophotometry (GC/MS). The antifungal activity of the oil was studied with regard to the inhibition of the growth of Aspergillus flavus PICC-AF39, Aspergillus flavus PICC-AF24, Aspergillus parasiticus NRRL-2999 and Aspergillus niger. The minimal inhibitory (MIC) and minimal fungicidal (MFC) concentrations of the oil were determined. Results: α-Pinene (29.2%), limonene (21.7%), 1,8-cineole (18.1%), linalool (10.5%), linalyl acetate (4.8%), and α-terpineole (3.17%) were the major components of the essential oil from C. cyminum L., and the oil showed a strong inhibitory effect on fungal growth. Conclusions: Essential oils could be safely used as preservatives in pharmaceuticals as well as health and food products to protect them against toxigenic fungal infections. © 2012 Kowsar Corp.

Ghorbani A.,Islamic Azad University at Abhar | Masoudi S.,Islamic Azad University at Abhar | Shabani A.,Islamic Azad University at Hidaj
Turkish Journal of Electrical Engineering and Computer Sciences | Year: 2012

In this paper, the Posicast control method is used for decreasing the reactive power oscillations of static shunt compensators. Shunt compensators such as the static synchronous compensator (STATCOM) and static VAR compensator (SVC) are considered to be FACTS devices. The applied control method decreases the amount of oscillations in the outputs of STATCOM and SVC considerably, with fast damping. In this paper, a PI controller is added to the model to decrease the sensitivity of the Posicast controller to the parameter variations and plant model mismatch. Simplicity and applicability are the main features of this controller. The model is simulated in a MATLAB/Simulink environment. © TÜBITAK.

Ashouri A.,Islamic Azad University | Bagheri A.,Islamic Azad University at Hidaj | Beykverdi M.,Islamic Azad University at Tehran
International Review on Modelling and Simulations | Year: 2012

This paper implements optimal PMU placement to make the network observable, and guarantees the observability of network under probabilistic events. With regards to the high cost of PMU units, another objective of the paper is minimizing of PMUs' installation cost. In this paper, for constructing and solving of optimization problem and optimal placement of PMU, an Improved Binary Shuffled Frog Leaping Algorithm (IBSFLA) has been used. To demonstrate the effectiveness of the propose method, it is applied to two test systems, IEEE 14-bus and 57-bus networks and the results of simulation in different scenarios are presented. The strength of solution method is examined by comparing the results with those obtained from Genetic Algorithm (GA) one from the optimality and convergence speed points of view. © 2012 Praise Worthy Prize S.r.l. - All rights reserved.

Shabani A.,Islamic Azad University at Hidaj
International Review on Modelling and Simulations | Year: 2011

The problem of power system expansion planning has large dimensions in generation and transmission sections. One of the required tools which have an important role in this problem analysis is power flow. Optimal DC power flow is faster than AC power flow and it is preferred for large problems. In this paper, an approach of fast optimal power flow based on DC power flow is presented and is formulated simply to be user friendly. The linear programming is used as an optimization tool to solve this problem. Finally, performance of the proposed approach is studied on a case. The results verify that this approach can be used as a tool in planning problems easily. © 2011 Praise Worthy Prize S.r.l. - All rights reserved.

Zavvari M.,Islamic Azad University at Urmia | Abedi K.,Shahid Beheshti University | Yusefli A.,Islamic Azad University at Hidaj | Karimi M.,Islamic Azad University at Mahabad
Optik | Year: 2015

In this paper, a novel design of quantum ring infrared photodetector (QRIP) is proposed based on an additional avalanche multiplication region and its performance theoretically is investigated. The device consists of two intrinsic regions including: (i) quantum ring based absorption region which is responsible for absorption longer wavelength radiations and (ii) avalanche multiplication region for multiplying the generated carriers in absorption layer. Since lower electric fields are needed for absorption region to keep the dark current low and higher fields are required for multiplication region, a highly doped charge layer is used to separate absorption and multiplication regions and non-uniformly distribute the electric field. Also to further reduction of dark current, resonant tunneling barriers are embedded in absorption region to provide only a pass for optically excited electrons. Simulation results shows a higher responsivity and specific detectivity about 40 A/W and 2 × 1010 cm Hz1/2/W at λ = 20 μm, respectively. © 2015 Elsevier GmbH. All rights reserved.

Discover hidden collaborations