(SoE) School of Engineering

<p>Shiv Nadar University is a comprehensive, multidisciplinary, research-focused, and student-centric University offering a full range of academic programs at the undergraduate, postgraduate and doctoral level. With state-of-the-art infrastructure, the University comprises of academic wings, sophisticated labs, international standard sports facilities, amphitheaters, auditorium, conference rooms and smart classrooms. The University&rsquo;s goal is to become internationally recognized for the quality of its research and creative endeavors and their applicability to improving quality of life, generating new insights and expanding the boundaries of human knowledge creativity. Committed to excellence in teaching, research and service, the University aims to serve the higher education needs of India and the world beyond.</p>

Shiv Nadar University

The electric field distribution (magnitude only) near a radiating source (antenna) can be easily determined using infrared thermography. A thin screen (made of carbon fiber reinforced polymers) is placed in front of a microwave source. The electromagnetic waves impinging on the screen are partially absorbed, resulting in temperature rise of the screen. This temperature rise is monitored by an infrared camera. The temperature distribution thus observed is mapped to the electric field strength (magnitude of electric field) of the electromagnetic waves. Points on the screen where the temperature rise is low correspond to weak electromagnetic fields whereas points with high temperature rise correspond to strong electromagnetic fields. In this paper electro-thermal modelling is done so as to obtain the temperature distribution over the screen, when an electromagnetic field is incident on it. This model can conversely be used for finding electromagnetic field distributions from IR thermal images. © 2017, Springer Science+Business Media, LLC.

World University root node

Electrical Engineering

Journal of Nondestructive Evaluation

Modelling and Analysis of Power Distribution of Electromagnetic Waves on Plane Surfaces Using Lock-in IR Thermography

High entropy alloys (HEAs) represent a new paradigm of structural alloys comprising of multiple principal elements in equimolar or near-equimolar concentration. The superior corrosion and oxidation resistance of HEAs at high temperature make them attractive for several structural applications. In this context, erosion behavior of HEAs has been largely unexplored. In this study, the slurry erosion performance of single phase Al0.1CoCrFeNi high entropy alloy was investigated. For comparison, mild steel and stainless steel (SS316L) were also investigated under similar conditions. The slurry erosion was conducted at different impingement angles and at a constant velocity of 20 m/s. The microstructural and mechanical characterization were conducted using scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), x-ray diffraction (XRD), nanoindentation and micro-hardness testing. Similar to the mild steel and stainless steel, HEA also showed ductile mode of erosion. The erosion rate for HEA was found to be higher compared to stainless steel, however in spite of lower tensile strength and hardness, HEA exhibited higher erosion resistance compared to mild steel. The high erosion resistance of HEA compared to mild steel is explained on the basis of its work hardening behavior, low stacking fault energy, and superior corrosion resistance. Erosion response of the investigated materials showed significant correlation with ultimate strength and ultimate resilience. In depth analysis of the eroded HEA samples showed ploughing as the prominent material removal mechanism at oblique angles compared to micro-cutting for SS316L and mild steel. In contrast, highly deformed and work-hardened platelets were observed at normal impingement angle for all materials. © 2017 Elsevier B.V.

Mechanical Engineering

Wear

Slurry erosion behavior of high entropy alloys

Marine and off-shore components including propellers, pumps, valves, pipelines and other submerged surfaces are subjected to severe degradation by erosion. Impingement of solid particles mixed in a liquid, referred as slurry, leads to significant material loss and shortens the life span of components. Tailoring the surface properties of materials is an economical way for addressing their degradation. Surface modification through high strain-rate deformation is widely used to enhance functional properties of materials. However, surface modification, particularly at low temperature, is extremely challenging for high strength materials such as stainless steel and has not been investigated comprehensively so far. In the present work, high strain-rate deformation of austenitic steel, SS316L, was performed by innovative submerged friction stir processing technique. For comparative studies, friction stir processing was also performed under ambient cooling conditions. Electron back scatter diffraction studies showed significant grain refinement for the sample processed under submerged conditions. The erosion behavior of as-received and processed steel was investigated using slurry erosion tests. Erosion tests were performed at constant impact velocity of 20 m/s and particle size, while varying the impingement angles. The sample processed under submerged conditions showed nearly two times higher erosion resistance compared to as-received steel. The enhancement in erosion resistance is explained using structural rejuvenation achieved at high strain-rate deformation. All the samples showed similar erosion mechanisms with micro-cutting and ploughing being evident at acute angles and platelet mechanism at normal impingement angle. Erosion phenomena showed a strong correlation with material's hardness at oblique impingement angle while, erosion behavior at normal impingement is explained by the flow work given as hardness to elastic modulus ratio. The study provides fundamental insights into material design for advanced structural applications. © 2017 Elsevier B.V.

High strain deformation of austenitic steel for enhancing erosion resistance

The paper presents a low cost method of actuation which is called lead-screw actuation for braille refreshable display. An array of six small sized independent motors are arranged in an array of 3×2 matrix. The shaft is coupled with a lead screw. Another internally threaded hexagonal nut is fitted on the lead screw which is constrained to move only in axial direction which actuates the pins. The device requires very low voltage and its operation is independent of temperature. The actuation of the pins can be achieved within 0.08 seconds as compared to 50 seconds in electrothermal braille refreshable display and 0.5 seconds in ionic polymer metal composite (IPMC) actuators. Moreover, no continuous power supply is required to retain the pins in the position once they have been actuated. © 2017 IEEE.

2017 4th IEEE Uttar Pradesh Section International Conference on Electrical, Computer and Electronics, UPCON 2017

Braille refreshable display using lead screw actuation

Centrality is an important measure to identify the most important actors in a network. This paper discusses the various Centrality Measures used in Social Network Analysis. These measures are tested on complex real-world social network data sets such as Video Sharing Networks, Social Interaction Network and Co-Authorship Networks to examine their effects on them. We carry out the correlation analysis of these centralities and plot the results to recommend when to use those centrality measures. Additionally, we introduce a new centrality measure - Cohesion Centrality based on the cohesiveness of a graph, develop its sequential algorithm and further devise a parallel algorithm to implement it. © 2016 IEEE.

Computer Science and Engineering

2016 IEEE International Conference on Advanced Networks and Telecommunications Systems, ANTS 2016

Correlating centralities of social networks

Deterioration of concrete due to sulphate attack is a major durability problem for concrete structures exposed to sulphate-rich soil and groundwater such as septic tanks, sewage pipes and water treatment plants. The continuous exposure to a sulphate-rich environment, concrete loses its strength and durability resulting in a reduction of the designed service life. The widespread occurrence of sulphate attack and the destruction caused by it have attracted researchers over the years into the study of the deterioration mechanism and methods to combat it. This paper deals with the monitoring of deterioration in concrete for accelerated sulphate environment and detecting damage using half-cell potential method, powder X-Ray diffraction and acid penetration test. The accelerated testing adopted here provides a realistic approach for predicting the deterioration of concrete under Sulphur attack. The paper demonstrates the various stages of changes occurred in cement composite during exposed environment and successfully monitored through conventional NDT Techniques. The results give in depth understanding microstructural behaviour of concrete elements during chemical attack. © 2017 Taylor & Francis Group, London.

Civil Engineering

Life-Cycle of Engineering Systems: Emphasis on Sustainable Civil Infrastructure - 5th International Symposium on Life-Cycle Engineering, IALCCE 2016

Monitoring and detection of damage in cement composite under sulphate attack

In this paper, we first make a theoretical and numerical analysis of electromagnetic (EM) vertex wave, which carries rotating phase (helical) front and orbital angular momentum (OAM). Subsequently 8 elements rectangular inset feed incrementally phased Circular Array (CA) Antenna is simulated which can generate Orbital Angular Momentum beam at 10 GHz. The simulated results verifies rotating phase with the result from the mathematical analysis. © 2016 IEEE.

Asia-Pacific Microwave Conference Proceedings, APMC

Generation of OAM mode using radially oriented Circular Array

Power conversion using multilevel convertes became very popular in past few years. They have the advantages of quality power output, high voltage compatibility, low electromagnetic compatibility concerns. © 2016 IEEE.

1st IEEE International Conference on Power Electronics, Intelligent Control and Energy Systems, ICPEICES 2016

Phase shifted PWM cascaded multilevel inverter for solar PV grid integration

Vehicle Indoor Air Quality (VIAQ) is a very important parameter that we often tend to ignore in our daily driving. VIAQ can worsen due to build-up of carbon dioxide (CO2), carbon monoxide (CO) and other harmful gases emitted by vehicles. Poor VIAQ can lead to short term health conditions like drowsiness, breathlessness, discomfort and headache. Drowsiness while driving is a predominant health condition that leads to large number of accidents and deaths all over the world. Standard equipment of air intake and recirculation in both low end and high end cars do not completely support pervasive maintenance of VIAQ. Due to unavailability of miniaturized sensors, a general purpose solution to this problem was rarely studied and addressed. In this work, we propose a novel mobile sensing system to monitor and understand change in VIAQ. Our mobile sensing system is general purpose, built by using an Android Smartphone and a mobile sensor, is independent of car age and model, and monitors VIAQ at all times. © 2016 IEEE.

2016 IEEE Annual India Conference, INDICON 2016

Real time in-vehicle air quality monitoring using mobile sensing

In this paper, we design a single transistor and zero-capacitor dynamic random access memory (DRAM or ZRAM) using band-gap engineered silicon-germanium (SiGe) Junctionless Double Gate Field Effect Transistor (JL-DGFET) device structure through 2D Sentaurus TCAD numerical simulations. We see that the inadequate charge storage capability of silicon-based 1T-DRAM is the main reason for short retention time. However, our simulations show that the performance can be further improved by replacing silicon substrate with silicon-germanium material. Moreover, a reduced breakdown voltage and hysteresis IDS-VDS characteristics are observed by putting SiGe as a bulk. Furthermore, the thickness of oxide and bulk material, and doping concentration are varied and their impacts are shown on the hysteresis output characteristic. High value of bipolar gain (β) is attained in designed band-gap engineered Si(1-x)Gex JL-DGFET transistors, which can be employed for enhancement of sensing margin in dynamic memories. © 2015 IEEE.