Seminar khoa hoc

9.00 AM - 10.00 AM:  Dr. Minh-Tri Nguyen-Le (AIMaS, TDTU)  presents the topic: "A facile route to fabricate AgNPs/PVA/Cellulose for in-situ detection of residual pesticides"

Abstract: This study reported a facile method to fabricate AgNPs/PVA/Cellulose substrate and use it as a Surface Enhanced Raman Scattering (SERS) substrate for the detection of chlorfenapyr, a well-known pesticide. AgNPs deposited on the PVA/cellulose substrate had an average size of 15.4 nm. Different characterization methods such as SEM, zeta potential measurement and UV-VIS were used to study the morphology, structure and stability of the obtained AgNPs and AgNPs/PVA/Cellulose substrate. Under the excitation of 532 nm laser, several enhanced Raman peaks of chlorfenapyr deposited on AgNPs/PVA/Cellulose substrate were observed at 1033 cm-1, 1457 cm-1, 1660 cm-1, 2234 cm-1 and 3077 cm-1. The detection limit of chlorfenapyr was 1 ppm. The results indicated that AgNPs/PVA/Cellulose could be used as a SERS substrate for in-situ detection of residual pesticides.

10.00 AM – 11.00 AM:  MSc. Anh-Tu Le (FEEE, TDTU) presents the topic: "Performance analysis of RIS-based wireless communication network"

Abstract: In this study, we investigated the performance of Reconfigurable Intelligent Surfaces (RIS)-based wireless communication network. In addition, RIS is equipped with N-reflecting elements to help reflecting the received signal to the destination. Therefore, RIS can achieve high spectral and energy efficiency at a low cost in wireless networks. More specifically, we considered the channels as Rayleigh/Nakagami-m/Rician fading distribution and calculated signal to noise (SNR) ratio. Then, we derived the closed-form expressions of outage probability (OP), ergodic capacity (EC), bit error rate (BER), etc. based on SNR. Furthermore, the asymptotic OP system is studied to get a better insight. Finally, all analytical results are verified by Monte Carlo simulation.