National Institute of Technology Jamshedpur (NIT Jamshedpur or NITJSR), is an Institute of National Importance located at Jamshedpur, Jharkhand, India. Established as a Regional Institute of Technology on 15 August 1960, it was upgraded to National Institute of Technology (NIT) on 27 December 2002 with the status of a Deemed University. It is one of the 31 NITs in India, and as such is directly under the control of the Ministry of Human Resource Development (MHRD). It is the third in the chain of 8 NITs established as a part of the Second Five Year Plan (1956–61) by the Government of India.
Hydroxyapatite (HA) and functionally graded HA-Al2O3-TiO2 coatings were deposited on Ti-6Al-4V alloy via plasma spraying, followed by heat treatment at 750 °C for 2 h. The effects of compositional gradation and heat treatment on microstructure, corrosion behavior, wettability, surface energy, and in vitro bioactivity were systematically evaluated. Both coatings exhibited porous, rough surfaces conducive to osseointegration, with heat treatment reducing roughness (HA: 3.5 to 3.0 µm; graded: 3.9 to 3.54 µm) and porosity (HA: 20 to 17
This study examines the influence of silicon carbide (SiC) particle size on the mechanical performance of AA7075/SiC composites fabricated via microwave sintering. Composites reinforced with SiC particles of varying sizes (60.7, 10.91, 5.33, and 0.73 μm) were synthesized, and their tensile strength, compressive strength, hardness, impact energy, and relative density were systematically evaluated. Microstructural characterization, including x-ray diffraction (XRD), was performed to elucidate the mechanisms governing the observed behavior. The results reveal a progressive improvement in mechanical properties with decreasing particle size. The composite reinforced with 0.73 μm SiC exhibited the highest tensile strength ( 362 MPa) and compressive strength ( 451 MPa), while intermediate particle sizes of 5.33 and 10.91 μm showed moderate improvements compared to the coarse 60.7 μm reinforcement, which exhibited comparatively lower strength. These improvements are primarily attributed to strong interfacial bonding, reduced porosity, and the activation of multiple strengthening mechanisms, such as the Orowan strengthening, and Zener grain pinning. Microwave sintering facilitated uniform densification and microstructural homogeneity, yielding a maximum relative density of 98.26
Radio frequency (RF) energy harvesting (EH) for wireless networks offers a green and sustainable solution, enhancing energy efficiency and ensuring the longevity of devices, even in remote, inaccessible locations. Such RF-EH mechanisms are utilized in simultaneous wireless information and power transfer systems. This study evaluates wireless information and power transfer in two-way relay networks, where two source nodes communicate directly and via a battery-powered relay node. This research presents new analytical results assuming the time switching protocol with amplify-and-forward relaying, and selection combining receiver to combine direct-link and relay-assisted signals over generalized η -μ fading channels. Our study derives novel analytical formulations for key performance measures, namely outage probability, system throughput, system energy efficiency, and the average symbol error rate of a generalized rectangular quadrature amplitude modulation scheme. In addition, an asymptotic analysis of the outage probability is carried out to determine the diversity order of the system. The resulting expressions are formulated as rapidly converging infinite series, which can be efficiently evaluated using only a limited number of terms. The influence of key system parameters, such as fading characteristics, target rate threshold, time switching ratio, energy conversion efficiency, relay location, and constellation order, is thoroughly examined. The accuracy of the proposed analytical framework is verified through numerical evaluation and Monte Carlo simulations, demonstrating excellent agreement between analytical and simulation results.
Nowadays, a wide range of media, including pictures, are used to communicate vast volumes of information. Novel approach must employ cryptographic methods like encryption to guarantee data security and ownership. To improve data security, novel developed chaotic map method for image encryption by combining two chaotic map algorithms, which presented in this work. The two different approaches are the 3D Henon map and the 3D Arnold's Cat map. Both the encryption and decryption processes use them in tandem. Using a 3D Henon map first, then a 3D Arnold Cat map, the final encrypted picture for transmission in this work is produced. After the encrypted picture is created, it goes through a reverse process that first uses 3D Arnold's Cat to decode it, follow by 3D Henon map to recover the resulting image. This proposed solution has a high entropy value, and provides users with extra performance requirements for security and unpredictability. For every small change in pixels, the unified average changing intensity (UACI) and number of pixels change rate (NPCR) are employed to verify the efficacy of image encryption algorithms.
Friction stir additive manufacturing (FSAM) is an emerging solid-state technique for producing high-strength aluminum composites with refined microstructures. However, challenges such as non-uniform reinforcement dispersion and weak interlayer bonding still limit the performance of multilayer FSAM components. In this study, AA7075 hybrid composites reinforced with zirconium dioxide (ZrO2) and graphene were fabricated using a groove-assisted multilayer FSAM technique. The primary objective of this work is to examine the influence of a tapered octagonal pin tool geometry on material flow behavior, microstructural evolution, reinforcement dispersion, and mechanical performance. Optical microscopy, scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS) were used for microstructural characterization, while hardness, tensile, wear, and friction tests were conducted to evaluate mechanical and tribological properties. Fracture behavior and tool surface conditions were further analyzed using SEM-based fractography and tool wear observations. The results show that the tapered octagonal pin tool promotes improved material flow, leading to a relatively uniform distribution of ZrO2 and graphene reinforcements with limited agglomeration and improved interlayer bonding. The fabricated composite exhibited enhanced hardness (up to 187.5 VHN) and tensile strength (up to 325 MPa) compared with the base alloy. Fractographic analysis revealed predominantly ductile fracture characteristics, indicating effective load transfer between the matrix and reinforcements. In addition, the composite demonstrated improved wear resistance with a reduced coefficient of friction. Tool surface analysis indicated minimal tool degradation during the FSAM process. The findings highlight the role of tapered octagonal pin tool geometry in improving reinforcement dispersion and mechanical performance in FSAM-processed AA7075/ZrO2/Gr hybrid composites, providing insights for optimizing tool design in solid-state additive manufacturing.
