University of Tabriz

About: University of Tabriz is a education organization based out in Tabriz, Iran. It is known for research contribution in the topics: Population & Nanocomposite. The organization has 12141 authors who have published 20976 publications receiving 313982 citations.

Voltage Sag Compensation of Point of Common Coupling (PCC) Using Fault Current Limiter

Abstract: In this paper, voltage sag compensation of point of common coupling (PCC) using a new structure of fault current limiter (FCL) is proposed. The proposed structure prevents voltage sag and phase-angle jump of the substation PCC after fault occurrence. This structure has a simple control method. Using the semiconductor switch (insulated-gate bipolar transistor or gate turnoff thyristor at dc current rout leads to fast operation of the proposed FCL and, consequently, dc reactor value is reduced. On the other hand, the proposed structure reduces the total harmonic distortion on load voltage and it has low ac losses in normal operation. As a result, other feeders, which are connected to the substation PCC, will have good power quality. Analytical analysis and simulation results using PSCAD/EMTDC software and experimental results are presented to validate the effectiveness of this structure.

Cavity soliton laser based on VCSEL with saturable absorber

Abstract: We study theoretically a broad-area vertical cavity surface emitting laser (VCSEL) with a saturable absorber. We show numerically the presence of cavity solitons in the system: they exist as solitary structures formed through a modulationally unstable homogeneous lasing state that coexists with a background with zero intensity. Such a peculiar scenario endows the solitons with unique properties compared to cavity solitons in most previously studied optical systems. In particular, these solitons do not as such rely on a proper phase of the addressing pulses to be either created or deleted. We show that exciting and deleting the solitons depend crucially on whether a threshold in the soliton peak has been reached.

Treatment of oral lichen planus with photodynamic therapy mediated methylene blue: A case report

Abstract: Oral lichen planus (OLP) is a common chronic disease of uncertain origin. Many patients with OLP are refractory to all available therapies. The photodynamic therapy (PDT) was used as a possible alternative method in the treatment of lichen planus. Two patients with five oral lichen planus lesions were treated using topical PDT mediated by methylene blue (MB-PDT). The patients were followed up on sessions 3, 7, 15 days and 1 to 9 months after PDT. Clinical improvement was achieved in four lesions. Two lesions showed complete remission, and another two lesions had about 50% clinically improvement 3-9 months after a single session of PDT. No response detected in one lesion. MB-PDT blue seems to be an effective alternative treatment for control of OLP. In our opinion, this preliminary result warrant further studies in order to show the efficacy of MB-PDT in control of OLP for a longer period of time.