National Institute of Technology, Meghalaya

About: National Institute of Technology, Meghalaya is a education organization based out in Shillong, India. It is known for research contribution in the topics: Control theory & Electric power system. The organization has 503 authors who have published 1062 publications receiving 6818 citations. The organization is also known as: NIT Meghalaya & NITM.

Structural, electrical and optical studies on ruthenium doped ZnO pellets for device applications

Abstract: Doped and undoped specimens of nano-particulate ZnO with 0.5 wt% and 1 wt% ruthenium were prepared through a chemical route. Structural characterization of the samples performed with XRD established that all the nanoparticles are of zinc oxide having polycrystalline nature. Morphological studies were conducted using FESEM to confirm the grain size and texture. Electrical measurements showed that the ac conductivity increases with frequency but decreases with increasing ruthenium concentration, making it a potential option for device applications. It is found that the absorbance does not significantly change with doping. The above fact is further confirmed from the bandgap calculations using the reflectance graphs. A decrease of bandgap from 3.42 to 3.19 eV with increasing Ru concentration is observed making it an important and advantageous material for potential visible light photocatalytic applications involving metal oxide nanostructures.

Damage-Free Hole Making in Fiber-Reinforced Composites: An Innovative Tool Design Approach

Abstract: Drilling is an inevitable machining technique that facilitates the assembly of composite parts. Drilling with the traditional tools causes significant damage to the composite parts. The forces that are produced during drilling are mostly accountable for the damage or rejection of the parts. Therefore, the main aim of the present investigation is to reduce the forces and subsequent damage that is induced during drilling operation. Thus, new tool geometry has been conceptualized, designed, developed, and implemented to investigate the drilling behavior of sisal-epoxy and nettle-epoxy laminates. A comparative analysis has been made to compare the performance of the developed tool with the widely used twist drill. The performance has been compared based on the forces and associated drilling-induced damage. It was found that the developed tool geometry gives better results than the traditional twist drill in terms of minimization of forces and damage as well.

A Novel Modified Control Scheme in Grid-Tied Photovoltaic System for Power Quality Enhancement

Abstract: In this article, a modified reduced order generalized integrator-based frequency-locked loop (MROGI-FLL) is proposed for controlling the interfacing inverter of the grid-tied photovoltaic system to mitigate the harmonics. Additionally, a fuzzy tuned PID controller is integrated in the proposed scheme to minimize the steady-state error, which results the voltage level is maintained constant at the common dc-link bus terminals. The MROGI-FLL is designed to evaluate the three-phase reference currents by extracting the fundamental constituents from the load currents and grid voltages. The proposed MROGI-FLL has several advantages such as better harmonic mitigation capability, control adaptivity, adaptive frequency and phase, grid synchronization, and low computation burden. The proposed reference current generator is simulated on MATLAB/Simulink platform under steady state and various transient conditions.The comparative study of proposed scheme is compared with the existing and adaptive control techniques, which assures the potency of the proposed control algorithm in-terms of harmonic mitigation, dc-offset rejection, frequency variation, and computation burden. Finally, the experimental results are verified through an experimental platform by using the dSPACE evaluation kit and both the simulation and hardware characteristics are well justified to the IEEE-519 standard limits.