(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 Jaya algorithm is a novel, simple, and efficient meta-heuristic optimization technique and has received a successful application in the various fields of engineering and sciences. In the present paper, we apply the Jaya algorithm to permutation flow shop scheduling problem (PFSP) with the multi-objective of minimization of maximum completion time (makespan) and tardiness cost under due date constraints. PFSP is a well-known NP-hard and discrete combinatorial optimization problem. Firstly, to retrieve a job sequence, a random preference is allocated to each job in a permutation schedule. Secondly, a job preference vector is transformed into a job permutation vector by means of largest order value (LOV) rule. To deal with the multi-objective criteria, we apply a multi-attribute model (MAM) based on Apriori approach. The correctness of the Jaya algorithm is verified by comparing the results with the total enumeration method and simulated annealing (SA) algorithm. Computational results reveal that the proposed optimization technique is well efficient in solving multi-objective discrete combinatorial optimization problems such as the flow shop scheduling problem in the present study. © Springer Nature Singapore Pte Ltd. 2020.

Mechanical Engineering

Advances in Intelligent Systems and Computing

An Efficient Jaya Algorithm for Multi-objective Permutation Flow Shop Scheduling Problem

In this manuscript, higher-order Orbital Angular Momentum (OAM) modes and parameters affecting vortex in the radiation pattern have been studied. A uniform circular array resonating at 10 GHz frequency is formed using eight identical rectangular patch antennas. Three uniform circular arrays are analyzed, simulated, and fabricated for OAM modes 0, +1, and-1 respectively. The higher-order OAM modes ±2, ±3, and ±4 are simulated and their effects on radiation and phase pattern are discussed. The effect of number of antenna elements and radius of the circular array on the phase purity of higher order OAM modes is presented. The results of simulated radiation patterns and phase front are well satisfying the generation of OAM modes. The measured results show a close agreement with the simulated result. © 2020, Iran University of Science and Technology. All rights reserved.

Electrical Engineering

World University root node

Iranian Journal of Electrical and Electronic Engineering

Study on generation of higher order orbital angular momentum modes and parameters affecting the vortex

Civil Engineering

Journal of Irrigation and Drainage Engineering

Closure to “Evaluation of the Vapor Pressure Models in the Estimation of Actual Vapor Pressure and Evapotranspiration” by Hitesh Upreti and C. S. P. Ojha

Fulltext

Journal of Hazardous, Toxic and Radioactive Waste

Climate Change and Sustainable Water Resources Management

In the present work, we developed eco-friendly and cost-effective nanocomposite coatings. These wax-derived coatings showed high superhydrophobicity while exhibiting mechanical and thermal robustness. The addition of nano-alumina particles in wax (Beeswax and Paraffin) significantly enhanced de-wetting (contact angle ~ 156°) with extremely low hysteresis (&lt;5°). The Paraffin-based composite coating showed better thermal (up to 50 °C) and mechanical (Δθ≈5°) (droplet impacts) stability than Beeswax counterpart, while also sustaining outdoor exposure. The superhydrophobic coatings showed self-cleaning ability with significantly low water consumption (&lt;1 μl/mm2). We showed that nanocomposite-wax coatings possess required durability and are potential candidates for developing non-fluorinated self-cleaning surfaces. © 2020 Elsevier B.V.

Materials Letters

High durability of non-fluorinated superhydrophobic nanocomposite coatings

A numerical investigation of the binary collision of two off-center unequal sized liquid droplets in the gaseous environment has been performed. The complete process of collision of droplets is dynamically simulated by solving the incompressible Navier–Stokes equations. Simulations are performed using three-dimensional, multiphase finite volume based solver in OpenFOAM platform. The gas-liquid interface is captured by using the volume of fluid (VOF) method. The solver is appropriately validated and is applied to study the effect of the droplet diameter ratio and the impact parameter on the droplet collision characteristics. The numerical study is done by fixing a moderately high Weber number and Reynolds number for unequal sized droplet collision, where stretching separation is expected as a collision outcome for equal sized droplets. The geometrical characteristics of ligament structures are presented both qualitatively and quantitatively. The satellite droplet formation is also well captured with the present simulations. Post-collision characteristics from the simulations are compared with an existing collision model. It is believed that the present study serves as a first step towards the development of a more accurate droplet collision models. © 2020

International Journal of Multiphase Flow

Detailed numerical simulations of unequal sized off-centre binary droplet collisions

In this current study, we developed SiC (10 wt\%) reinforced AlCoCrFeNi complex concentrated alloy composite claddings with different particle sizes (micro, nano and bimodal) on stainless steel 316L substrate using microwave irradiation. Microstructural analysis showed cellular structured claddings with intermetallic phases occupying the intercellular regions along with low porosity (&lt;1\%). The claddings were mainly composed of A2 (disordered BCC) and B2 (ordered BCC) along with Cr23C6. The bimodal (mixture of nano and micro) composite cladding showed highest hardness and fracture toughness (810 HV and ~12.2 MPa√m) followed by nano and micro composite claddings. Under cavitation erosion (distilled water) condition, bimodal cladding showed highest incubation period (IP) (~13 h) with extremely low mean depth erosion rate (MDER) (~0.089 μm/h) with 16 and 27 times lower than stainless steel 316L and WC-based coating, respectively. The cavitation erosion resistance observed for the bimodal composite cladding is among the highest demonstrated by the CCAs at present. However, under erosion-corrosion conditions, non-reinforced and micro-reinforced claddings showed higher degradation resistance with lower material removal rates than that observed for bimodal cladding. Standalone electrochemical corrosion studies also showed highest corrosion and passivation resistance for non-reinforced cladding. These results were explained on the basis of formation of Cr-depleted micro-galvanic cells due to high negative enthalpy of Cr with C dissociated from SiC particle. The detailed morphological analysis of the tested samples showed presence of tearing top surface as the primary degrading mechanism along with fracture of intermetallic phases. The results show that bimodal composite CCA cladding provides a potential surface engineering solution for improvising the serviceability of the many engineering systems. © 2020 Elsevier B.V.

Surface and Coatings Technology

Complex concentrated alloy bimodal composite claddings with enhanced cavitation erosion resistance

The leaching out of toxic elements from metallic bioimplants has serious repercussions, including allergies, peripheral neuritis, cancer, and Alzheimer's disease, leading to revision or replacement surgeries. The development of advanced structural materials with excellent biocompatibility and superior corrosion resistance in the physiological environment holds great significance. High entropy alloys (HEAs) with a huge compositional design space and outstanding mechanical and functional properties can be promising for bioimplant applications. However, microstructural heterogeneity arising from elemental segregation in these multiprinciple alloy systems is the Achilles heel in the development of next-generation HEAs. Here, we demonstrate a pathway to homogenize the microstructure of a biocompatible dual-phase HEA, comprising refractory elements, namely, MoNbTaTiZr, through severe surface deformation using stationary friction processing (SFP). The strain and temperature field during processing homogenized the elemental distribution, which was otherwise unresponsive to conventional annealing treatments. Nearly 15 min of the SFP treatment resulted in a significant elemental homogenization across dendritic and interdendritic regions, similar to a week-long annealing treatment at 1275 K. The SFP processed alloy showed a nearly six times higher biocorrosion resistance compared to its as-cast counterpart. X-ray photoelectron spectroscopy was used to investigate the nature of the oxide layer formed on the specimens. Superior corrosion behavior of the processed alloy was attributed to the formation of a stable passive layer with zirconium oxide as the primary constituent and higher hydrophobicity. Biocompatibility studies performed using the human mesenchymal stem cell line, showed higher viability for the processed HEA compared to its as-cast counterpart as well as conventional metallic biomaterials including stainless steel (SS316L) and titanium alloy (Ti6Al4V). Copyright © 2020 American Chemical Society.

ACS Applied Bio Materials

Enhanced Biocorrosion Resistance and Cellular Response of a Dual-Phase High Entropy Alloy through Reduced Elemental Heterogeneity

This paper presents an alternate design for a conventional 3dB Branch line coupler (Quadrature Coupler) for C Band applications. The proposed coupler is designed for 5.2GHz. The proposed coupler has parallel-coupled lines at the port of conventional 3dB coupler with slotted ground plane. The novel design of the coupler allows 82.6\% of bandwidth improvement with DC(Direct Current) isolation. The designs have been simulated and fabricated on FR4 dielectric substrate and measured using Vector Network Analyzer. Simulated and fabricated results of the S-parameters are presented. © 2020 IEEE.

2020 7th International Conference on Signal Processing and Integrated Networks, SPIN 2020

Quadrature coupler with enhanced coupling bandwidth and DC isolation for C-band applications

This paper presents an unconventional design for a circular rat race coupler operating at 5 GHz frequency. The size of the novel design implemented is 21.68mm x 15.72mm. The unconventional design of the coupler allows 40\% reduction in the size of the coupler as compared with the conventional rat race coupler without compromising on performance. Measured and simulated results of the S-parameters are provided. © 2020 IEEE.