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.

Entropy Generation Analysis of the MHD Flow of Couple Stress Fluid between Two Concentric Rotating Cylinders with Porous Lining

Abstract: An attempt has been made to study the entropy generation analysis of couple stress fluid flow in an annulus between two concentric rotating vertical cylinders. There is a porous lining attached to the inside of an outer cylinder. The flow is under the influence of a radial magnetic field. The flow in the annular gap is caused by rotation of the cylinders. The Stokes couple stress flow model is employed. The flow in the porous sleeve is governed by Darcy's law. The velocity, temperature, entropy generation number, Bejan number, wall shear stress and heat transfer rate at the inner and outer cylinders are obtained numerically by employing a finite difference scheme with vanishing of couple stresses on the boundary. The effect of relevant parameters on the flow and entropy generation rate are discussed and depicted through graphs.

Microwave assisted synthesis of Co3O4 and NiO nanoplates and structural, optical, magnetic characterizations

Abstract: The surfactant and template free Co3O4 and NiO nanoplates have synthesized using microwave assisted method. Synthesized Co 3 O 4 and NiO nanoplates were characterized using X-ray diffraction (XRD), Scanning electron microscope (SEM), Energy dispersive spectrometer (EDS) for their Structural, morphological and elemental analysis respectively. The Fourier transform infrared (FTIR) spectra of both samples were recorded for the oxide compound confirmation. Optical and magnetic characterizations were studied by using UV–Visible absorption spectroscopy, photoluminescence (PL) and vibrating sample magnetometer (VSM) respectively. Average crystallite sizes for Co 3 O 4 and NiO nanoplates were found to be 21 nm and 17 nm respectively by using Debye–Scherrer’s formula. The energy band gaps for Co 3 O 4 and NiO nanoplates were calculated using Tauc plot and values are 3.3 eV and 3.1 eV respectively. BET surface areas of Co 3 O 4 and NiO nanoplates were measured to be 29 m2/g and 92 m2/g respectively. The magnetization of Co 3 O 4 and NiO nanoplates as a function of magnetic field were recorded at room temperature showing a small hysteresis loop with coercivity of ∼ 534 and ∼ 152 Oe respectively. Microwave assisted method can be useful for the synthesis of Co 3 O 4 and NiO nano morphological materials for supercapacitor application.

A Context-Aware Fog Enabled Scheme for Real-Time Cross-Vertical IoT Applications

Abstract: As the Internet of Things (IoT) paradigm is maturing, innovative, and novel services are being envisioned. An upcoming trend is the depiction of services enacted through seamless integration of multiple vertical IoT services, termed as cross-vertical or unified IoT services in this paper. Traditional Cloud-based centralized network architectures cannot cater to real-time responses demanded by such unified IoT applications. Moreover, introducing Fog nodes within the network architecture, though a promising alternative, cannot sustain the burden of a huge number of applications that culminates in massive data handling. In this paper, we envision employing lessons learned from context-aware computing, specifically context sharing among interdependent vertical IoT applications to address this delay requirement of such unified IoT applications by enacting context sharing among Fog nodes for minimizing system delay. The detailed network model and context sharing mechanism have been presented and the service time minimization has been framed as an optimization problem. Algorithms for context sharing and delay tolerant load balancing have been presented and simulation results carried out demonstrate the efficacy of the proposed methodology.

A Self-Reliant DC Microgrid: Sizing, Control, Adaptive Dynamic Power Management, and Experimental Analysis

Abstract: This paper presents an adaptive power management and control for a self-reliant dc microgrid powered by photovoltaic (PV) array and fuel cell stack that is escorted with the supercapacitor- and electrolyzer-based hybrid energy storage device. The prime operational impediments associated with this dc microgrid are the unpredictable variations in the PV generation and load demand, fuel starvation phenomenon of the fuel cell, the time constant associated with the electrolyzer operation, and state-of-charge limitation of the supercapacitor. In this paper, the above-mentioned issues are addressed by employing an adaptive dynamic power management strategy (ADPMS) that supervises the overall power flow in the system. The ADPMS enables the co-existence of high power density and high energy density storage devices to deliver the power flow required by the loads. The expeditious support extended by the supercapacitor helps in swift regulation of the dc-link voltage during unforeseen transient load/source power variations. The electrolyzer–fuel cell combination employed in this system can supplement a battery bank and can equip high energy density and self-reliance to the system. The set-reset flip-flop based fixed frequency current controller is simple and effective in accurately tracking the reference currents established by the ADPMS. The proposed ADPMS along with the control is validated for transient unforeseen load profiles and renewable generation changes via simulation studies and its performance is also validated through an experimental analysis on a laboratory-scale dc microgrid testbed.

Microplastics in soils: an environmental geotechnics perspective

Abstract: Microplastics (MPs) are emerging persistent contaminants in the terrestrial subsurface, and evidence has emerged for significant effects of MPs on the biological and ecosystem functions of soils. M...