Islamic Azad University

About: Islamic Azad University is a education organization based out in Tehran, Iran. It is known for research contribution in the topics: Population & Catalysis. The organization has 83635 authors who have published 113437 publications receiving 1275049 citations. The organization is also known as: Azad University.

Nanomaterial-based biosensors for detection of pathogenic virus

Abstract: Viruses are real menace to human safety that cause devastating viral disease. The high prevalence of these diseases is due to improper detecting tools. Therefore, there is a remarkable demand to identify viruses in a fast, selective and accurate way. Several biosensors have been designed and commercialized for detection of pathogenic viruses. However, they present many challenges. Nanotechnology overcomes these challenges and performs direct detection of molecular targets in real time. In this overview, studies concerning nanotechnology-based biosensors for pathogenic virus detection have been summarized, paying special attention to biosensors based on graphene oxide, silica, carbon nanotubes, gold, silver, zinc oxide and magnetic nanoparticles, which could pave the way to detect viral diseases and provide healthy life for infected patients.

Design and Tuning of a Modified Power-Based PLL for Single-Phase Grid-Connected Power Conditioning Systems

Abstract: One of the most important aspects for the proper operation of the single-phase grid-tied power-conditioning systems is the synchronization with the utility grid. Among various synchronization techniques, phase locked loop (PLL)-based algorithms have found a lot of interest for the advantages they present. Typically, the single-phase PLLs use a sinusoidal multiplier as the phase detector (PD). These PLLs are generally referred to as the power-based PLL (pPLL). In this paper, the drawbacks associated with the pPLL technique (i.e., the sensitivity to the grid voltage variations, and the double-frequency oscillations that appear in the estimated phase/frequency) are discussed in detail, and some of the previously reported solutions are examined. Then, to overcome these drawbacks, a simple and effective technique, called the double-frequency and amplitude compensation (DFAC) method is proposed. The effectiveness of the proposed method is evaluated through a detailed mathematical analysis. A systematic design method to fine-tune the PLL parameters is then suggested, which guarantees a fast transient response, a high disturbance rejection capability, and a robust performance. Finally, the simulation and experimental results are presented, which highlight the effectiveness of the proposed PLL.