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 & Computer science. The organization has 503 authors who have published 1062 publications receiving 6818 citations. The organization is also known as: NIT Meghalaya & NITM.

Viscous Dissipation and Chemical Reaction Effects on Tangent Hyperbolic Nanofluid Flow Past a Stretching Wedge with Convective Heating and Navier’s Slip Conditions

Abstract: In this paper, an analysis is carried out for MHD boundary layer flow of a tangent hyperbolic nanofluid past a stretching wedge taking Navier’s velocity slip boundary condition along with convective heating at the wedge surface. The aspects of thermal radiation, internal heat generation, viscous dissipation and first-order chemical reaction are also considered. For approximating the radiative heat flux, Rosseland’s approximation is employed. The dimensional governing equations are converted into dimensionless forms by employing some suitable similarity transformation, and the resulting highly nonlinear boundary value problem is solved numerically with the help of shooting technique along with fourth-order Runge–Kutta method. The impacts of different controlling parameters on concentration, temperature and velocity fields are analyzed with the help of figures. Numerical values of Sherwood number, skin friction coefficient and Nusselt number are explained and presented in tabular form. For some special cases of the current investigation, obtained results are validated and are found to be in good agreement with the existing results. For growing values of velocity slip parameter, fluid velocity is accelerated, while temperature and concentration profiles are declined. Fluid temperature is enhanced upon increasing the heat generation parameter and Eckert number. For rising values of chemical reaction parameter, concentration profile is highlighted everywhere in the boundary layer region.

HLBC: A Hierarchical Layer-Balanced Clustering Scheme for Energy Efficient Wireless Sensor Networks

Abstract: Battery lifetime maximization of Wireless Sensor Network (WSN) nodes has been an area of prime research interest, and clustering of WSN nodes for realizing the goal of network lifetime maximization has been extensively addressed in the literature. Various clustering schemes for partitioning WSN nodes into equal, unequal or random cluster sizes have been prevalent, each having their own set of pros and cons. This paper proposes a Hierarchical Layer-Balanced Clustering (HLBC) scheme that partitions the WSN into a number of hierarchical layers of varied sizes while maintaining equal sized clusters at every layer. The proposed HLBC architecture is presented along with the proposed Frame Forwarding Algorithm (FFA) and the proposed TDMA Schedule for eliminating the synchronization problem. Extensive simulation experiments have been carried out under varying network scenarios to assess the performance of the proposed scheme, and the results demonstrate its efficacy. In particular, the proposed HLBC was found to outperform state of the art approaches LEACH, UCR and EMUC by 77.71%, 54.23% and 27.93%, respectively, in terms of Network Lifetime.

Reduced Switch Count Seven-level Self-Balanced Switched-Capacitor Boost Multilevel Inverter

Abstract: Active neutral point clamped multilevel inverters (MLIs) are most promising in photovoltaic systems to reduce the requirement of multiple sources and reduce the leakage current by clamping the ac-side neutral point to the mid-point of the dc-link. However, these structures suffer from the requirement of a more number of switches, voltage balancing problems and lack of voltage boosting. To get rid of these issues, this work first introduces a generalized single-dc MLI topology using switched-capacitor (SC) concept. After a detailed investigation of the structure, the seven-level (7L) configuration is derived. Only eight switches are required to generate a 7L output with 1.5 times voltage boosting. In medium and high-voltage applications, the proposed generalized MLI can be suitably operated as the peak switch stress is limited to the input voltage magnitude (V in ). Two floating capacitor voltages are effectively maintained at 0.5 V in and other capacitor voltages are maintained at V in without any additional sensors/voltage balancing controller. A detailed comparative analysis, along with simulation and experimental results under several dynamic test conditions are presented to validate the viability of the proposed single-phase MLI.