(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

In the current study, the high temperature oxidation behavior of AlCoCrFeNi high entropy alloy (HEA) following severe shear deformation was investigated. X-ray diffraction and transmission electron microscopy analysis confirmed spinodal distribution of B2 and BCC phase in the as cast specimen. In contrast, the processed specimen showed a dual phase microstructure (B2/BCC+FCC) after shear deformation. Electron backscattered diffraction analysis revealed significant grain refinement from 90 µm for the as-cast HEA to nearly 2 µm for the processed specimen. The processed specimen showed up to 66% reduction in the oxidation kinetics compared to the as cast alloy. The remarkable improvement in the high-temperature oxidation performance following processing is attributed to complete microstructure refinement. The current study provides a sustainable solution and a new pathway for addressing the looming problem of material deterioration at high temperatures. © 2022 Elsevier B.V.

World University root node

Mechanical Engineering

Journal of Alloys and Compounds

High oxidation resistance of AlCoCrFeNi high entropy alloy through severe shear deformation processing

Isogeometric collocation (IGA-C) method is a computational approach to solve boundary value problems. In this method (IGA-C), the differential equations are solved in strong form instead of the weak form approach adopted by Galerkin based formulations. IGA-C method is computationally efficient in comparison to conventional finite element method and Galerkin-Isogeometric approaches. IGA-C method does not involve the process of assembling global stiffness matrix from element stiffness matrix. Another advantage of IGA-C is that it requires a single integration point per element irrespective of the order of Non-Uniform Rational B-Spline functions (NURBS) adopted. Isogeometric collocation has also been demonstrated as a stable, efficient and accurate higher order computational method for explicit problems. For a wider adoption of isogeometric collocation method, beam/plate/shell finite elements within the framework of IGA-C method need to be formulated. Owing to the extensive adoption of laminated composites in structural components, development of beam finite elements for laminated composite beams based on isogeometric collocation method will prove useful during analysis of composite structures. IGA-C method is proposed in this study for the static bending, free vibration and buckling analysis of laminated composite beams. Classical laminated plate theory (CLPT), first order shear deformation theory (FSDT) and higher order shear deformation theory (HSDT) are considered for all the three analyses. The computational approach proposed for laminated beam based on HSDT contains two Degrees of Freedom (DOF) per node. Computational approach for analysing laminated composite beams based on each of these kinematic theories and using IGA-C method is presented. Accuracy of the proposed computational approaches is checked by solving different numerical examples. Values of normalized transverse displacement, normalized stresses, normalized natural frequencies and normalized critical buckling loads are compared with results from the literature and are found to be accurate. © 2022 Elsevier Masson SAS

Civil Engineering

European Journal of Mechanics, A/Solids

Static, free vibrational and buckling analysis of laminated composite beams using isogeometric collocation method

In this article, a V-groove weld joint of P92 steel, typically used in ultra-supercritical power plants, has been numerically analyzed to estimate transient temperature distributions and residual stresses. A weld simulation model using Prescribed Temperature approach was developed. This approach was used to reduce the computational expenditure and speed up the time-intensive analysis setup. The finite element method was employed to compute the residual stresses generated in the weld region and the heat-affected zone along the thickness of the plate. In the experimental investigation, the through-thickness residual stresses were measured using the deep-hole drilling (DHD) method. Good agreement was observed between numerically and experimentally obtained residual stresses. The maximum temperature was observed at the weld pool area which decreased in the parabolic trend toward the base metal. © 2022, The Indian Institute of Metals - IIM.

Transactions of the Indian Institute of Metals

Numerical Simulation of Temperature Fields and Residual Stresses in Multi-Pass Weld Using the Novel Prescribed Temperature Approach with Experimental Validation

The influence of circular cut-outs and geometric imperfection on the free vibration analysis of functionally graded material (FGM) sandwich plates with (2-1-2) plate configuration conditions has been investigated in this paper. Geometric imperfections, such as sine-type and global-type imperfections, are especially susceptible to plate vibration analysis, and these imperfections can be considered while studying plate vibration behavior. The governing equations are formulated based on the Lagrangian principle for the vibration analysis of the FGM sandwich plates subjected to the simply-supported and clamped boundary conditions. The results have been obtained using a C0-continuity isoparametric formulation with four noded elements having seven degrees of freedom per node. The accuracy of the present results has been confirmed by comparing the present results with the reported literature. © 2022

Materials Today: Proceedings

Influence of geometric imperfections on the free vibrational response of the functionally graded material sandwich plates with circular cut-outs

This study presents the utilization of paper mill sludge (PMS) as biomass for producing hydrogen from steam gasification. PMS is a wet waste and its utilization for hydrogen production would give a new direction to its management. In this work, the performance of PMS during steam gasification was studied by varying the steam flow rate (SFR) and by determining the various characteristics of product gas such as syngas yield, syngas composition, and its high heating value (HHV). The SFR was varied from 0.25 mL/min to 1.0 mL/min depending upon the steam to biomass ratio. The performance parameter, cold gas efficiency (CGE) was also determined to evaluate the performance of PMS during steam gasification and the highest CGE was found to be around 96% at optimal SFR. The optimal SFR was found to be 0.75 mL/min and the syngas characteristics at optimal SFR were found to be 1.4 m3/Kg (syngas yield), 58% (hydrogen fraction in syngas), and 11.92 MJ/m3 (HHV). The feasibility of the PMS management and its utilization using steam gasification methods can further be increased by using renewable sources of energy for heating the gasifier. © 2022 Informa UK Limited, trading as Taylor & Francis Group.

Chemical Engineering

Biofuels

Utilization of paper mill sludge as a sustainable source of hydrogen production

Skin cancer is considered to be the most common human malignancy. Around 5 million new cases of skin cancer are recorded in the United States annually. Early identification and evaluation of skin lesions are of great clinical significance, but the disproportionate dermatologist-patient ratio poses a significant problem in most developing nations. Therefore a novel deep architecture, named as SkiNet, is proposed to provide faster screening solution and assistance to newly trained physicians in the process of clinical diagnosis of skin cancer. The main motive behind SkiNet’s design and development is to provide a white box solution, addressing a critical problem of trust and interpretability which is crucial for the wider adoption of Computer-aided diagnosis systems by medical practitioners. The proposed SkiNet is a two-stage pipeline wherein the lesion segmentation is followed by the lesion classification. Monte Carlo dropout and test time augmentation techniques have been employed in the proposed method to estimate epistemic and aleatoric uncertainty. A novel segmentation model named Bayesian MultiResUNet is used to estimate the uncertainty on the predicted segmentation map. Saliency-based methods like XRAI, Grad-CAM and Guided Backprop are explored to provide post-hoc explanations of the deep learning models. The ISIC-2018 dataset is used to perform the experimentation and ablation studies. The results establish the robustness of the proposed model on the traditional benchmarks while addressing the black-box nature of such models to alleviate the skepticism of medical practitioners by incorporating transparency and confidence to the model’s prediction. Copyright: © 2022 Singh et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.

Computer Science and Engineering

Fulltext

PLoS ONE

SkiNet: A deep learning framework for skin lesion diagnosis with uncertainty estimation and explainability

Structural integrity of oil and gas pipelines depends on fracture toughness and metallurgical properties of pipeline steel welded joints. Dynamic fracture toughness (JId) is an important parameter to measure structural integrity in terms of fracture toughness of pipeline steel welded joints under impact loading. Welding input parameters such as current (A), voltage (V), and travel speed (cm/m) significantly affect the mechanical and metallurgical properties of the weldments; therefore, to study the cumulative effect of these parameters, author(s) used different heat input (kJ/cm) as an input parameter in the present work. In the present work, three different levels of heat input such as low heat input (LHI)15 kJ/cm, medium heat input (MHI)20 kJ/cm, and high heat input (HHI) 25 kJ/cm were employed for the fabrication of X80 pipeline steel welded joints. Thereafter, mechanical and metallurgical behavior of different locations (Fusion line (FL), FL + 1 mm, FL + 2 mm, and FL + 3 mm) in multi-pass X80 pipeline steel weld joint was investigated under cold climatic conditions (− 20 °C). The dynamic fracture toughness was measured from instrumented Charpy impact test results using three different estimation methods. Furthermore, a finite element model was developed to simulate the Charpy impact test and validate the experimental results, using the Johnson–Cook constitutive model. © 2022, International Institute of Welding.

Welding in the World

Experimental characterization of dynamic fracture toughness behavior of X80 pipeline steel welded joints for different heat inputs

This paper presents the influence of randomness in material properties on the vibration response of functionally graded (FG) nanoplates using the nonlocal continuum model. Material properties such as Elastic modulus, Poisson’s ratio, and volume fraction index are modeled as independent random variables. A trigonometric shear-strain shape function-based refined shear deformation theory in conjunction with non-local theory has been presented for the first time to investigate the stochastic vibrational response of FG nanoplate. An efficient stochastic finite element formulation has been documented to capture the first- and second-order statistics of natural frequency. The first-order perturbation technique has been used to accommodate the effect of various material uncertainties parameters. The effective material properties have been computed using the recently developed modified rule of mixture to incorporate the porosity inclusion. The influence of conventional and unconventional (partial support) boundary constraints, porosity inclusion, small-scale effects, and material uncertainties on the vibration response of FG plates has been investigated in detail. In addition to this, the sensitivity of the functionally graded nanoplate has been observed in response to initial geometrical imperfection. It is observed that the variations in elastic modulus have a significant influence on the stochastic characteristics compared to Poisson’s ratio. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.

Archive of Applied Mechanics

Size-dependent stochastic vibration response of compositionally graded nanoplates with system randomness using nonlocal continuum model with partial support

5G is expected to support enhanced Mobile broadband (eMBB), massive machine-type communication (mMTC), and ultra-reliable low latency communication (uRLLC). 5G vision relies on a successful rollout of mmWave frequency technology. The millimeter (mm) Wave frequency band 6–100 GHz range provides more BW to achieve higher data rate but it supports 50–200 m short range only. 5G NR leverages the latest development in multi-input multi-output antennas (MIMO) and beam formation to minimize spectral efficiency and provide better quality of service for large number of users. Beam forming technology has been introduced in mmWave frequency band to compensate high path losses due to mmWave frequencies. Beam formation aims to generate different beams for different user equipment (UE) using an array of antennas elements at the base station (BS) to communicate between different users. The effective beams undergo minimum power loss and interferences and are aimed to direct towards the user equipment. In this paper, we have simulated different types of arrays and analyzed different beam contours that are generated from the arrays of antennas to transmit to the user equipment. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

Electrical Engineering

Lecture Notes on Data Engineering and Communications Technologies

Impact of Beam Formation on 5G Mobile Communication Network in mmWave Frequency Band

This work proposes a design of triangular metamaterial loaded antenna with low RCS, which can be employed for space research and stealth applications. Circular and upturned C-shaped resonating slots are introduced in the rectangular patch to aid in miniaturization and impedance matching respectively. The reduced RCS, triangular SRR and CSRR are entrenched on the top and ground plane respectively; these have the added advantage of a compact unit cell. The two radiating edges of the antenna are loaded with dual-section stepped impedance resonators to curb the reflection of the impinging signal. The proposed antenna resonates at 2.25 GHz with a reflection coefficient of -20.83dB. The gain of the antenna is 4.11dBi, which is typical of a low RCS radiator. The impedance bandwidth is 46.5MHz and the antenna has a low monostatic RCS of -23.796dBsm at the fundamental resonant frequency. Since the antenna has a low RCS at the resonance frequency, it can be utilized for defense and stealth applications. © 2022 IEEE.