Browsing by Author "Rai, S.K."

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Cross Platform Web Accessible Remote Experiment Architecture using NI PXI, LabVIEW Web Server and Javascript Libraries
(Institute of Physics, 2025) Bidari, L.; Kaup, P.S.; Bidari, K.; Rai, S.K.; Gangadharan, G.
Remote Laboratories have become vital tools for education, research and industrial training, enabling experimentation beyond spatial and temporal constraints. The increasing need for flexible and accessible experimentation necessitates the development of robust remote laboratory architectures built using reliable proprietary hardware. This work presents such a remote laboratory architecture developed for two vibration experiments. The current work leverages a National Instruments PXI system alongside LabVIEW for experiment automation and web based control. The backend is built using the LabVIEW web server coupled with Google Javascript and AJAX libraries. This kind of design ensures platform-independent access via standard web browsers on laptops and mobile devices. Performance evaluation of the developed system demonstrated the system's efficiency and responsiveness. Upon receiving the user input via the browser based user interface, the experiment is triggered swiftly within 0.5 seconds. A ten-second graphical representation of acquired vibration data complete with precise acquisition timestamps is displayed on the client's browser, providing real-time feedback. This accelerated processing power is due to the integration of web server and controller in a single system. Â© Published under licence by IOP Publishing Ltd.
Development of thick SiC coating on thin wall tube of zircaloy-4 using laser based directed energy deposition technique
(Elsevier B.V., 2020) Rai, A.K.; Srinivasulu, B.; Paul, C.P.; Singh, R.; Rai, S.K.; Mishra, G.K.; Bontha, S.; Bindra, K.S.
In the present study, optimization of various laser-processing parameters for the deposition of thick SiC coating on zircaloy-4 (Zry-4) tube is studied in view of the development of accident tolerant fuel clad material for current and future nuclear reactors with the enhanced safety. The SiC coatings are deposited using laser directed energy deposition (LDED). It is found to be quite challenging to deposit desired SiC coating on a thin (~400 ?m) substrate of Zry-4 tubes due to either its excessive melting or damage. This is minimized largely by cooling the tube from inside by passing Ar gas (20 l min?1). It is observed that different processing parameters play a vital role on homogeneity, uniformity and defects-free SiC coatings as well as on the melting and oxidation of Zry-4 substrate. A uniform and homogeneous coating of SiC is deposited on Zry-4 at the optimized laser power density of 4.52 kW cm?2, powder feed rate of 2.71 g min?1and scan speed of 325 mm min?1. The interface between SiC coatings and substrate is characterized using different techniques such as optical microscopy, scanning electron microscopy and X-ray diffraction to access the homogeneity, uniformity, defects and to identify the different phases formed in the coated layer. Coated layer is found to be consisting of Zr(?), SiC, ZrSi2, ZrSi and ZrC types of phases and the same is also confirmed by the ThermoCalc(R) based ternary phase diagram. Further, the effect of processing parameters on substrate melting and the nature of SiC coating is explained by simulating the substrate temperature using COMSOL@ multi-physics. To the author's best knowledge, this would be the first study to report the laser directed energy deposition of SiC on Zry-4 alloy. © 2020 Elsevier B.V.
Experimental investigation for vibration attenuation for power tools
(American Institute of Physics, 2025) Kamath, N.; Shenoy, P.; Tanappagol, P.S.; Rai, S.K.; Kalluvalappil, G.
Construction zones are often buzzing with "chatter"emanating from different machines. The most commonly used machines are hand-held power tools that handle materials such as bricks, concrete, and other masonry-related materials. The labourers are exposed to vibrations from the device during operation for a prolonged period, causing lasting damage to the hand-arm system. Many factors lead to the unpredictable behaviour of the machine, making it difficult to manoeuvre. Increased gripping forces result in the hand-arm system being a better vibration medium. To counteract this effect, smart materials can stabilise the system. Magnetorheological Elastomers are one such material that can solve the problem of stabilising the device as they can adapt to different conditions, providing semi-active isolation for a wide range of frequencies and demonstrating its force-dependent behaviour. A handle made of MRE can be used to replace the conventional handle at the chuck region. This paper presents how the handle behaves in static conditions under the influence of different magnetic fields for an impact hammer test. Â© 2025 Author(s).
Tunable Vibration Control in Power Tool Handles Using a Magnetorheological Elastomer Device
(Institute of Physics, 2025) Sathiyasai, S.; Kamath, N.; Shenoy, K.P.; Rai, S.K.; Tanappagol, P.S.; Rajesh; Gangadharan, G.
A novel modular device integrating a magnetorheological elastomer (MRE) has been designed for adaptable attachment to various power tool auxiliary handles using their standard circular clamp and T-headed bolt mechanism. The core of the electromagnet of the device serves as the primary attachment interface. A relative validation approach was adopted to characterize its vibration control capabilities across different tool configurations. Instead of device-specific testing, the modular unit, loaded with supplementary masses of 1 kg and 1.5 kg to simulate various power tool weights, was mounted on a shaker and exposed to a defined vibration spectrum. The effect of varying the magnetic field strength on the dynamic behavior of the MRE-based isolator was examined. Experimental results reveal a notable positive shift in the system's natural frequency of approximately 3 Hz, transitioning from 12 Hz to 15 Hz when the maximum magnetic field was applied. Concurrently, the transmitted vibration amplitude was substantially reduced, averaging around 12%, under the same maximum field conditions. These findings highlight the potential of this modular MRE device as a versatile and easily integrable solution for tunable vibration damping in a wide array of power tools. Its semi-active nature offers a pathway to significantly enhance user comfort, reduce operator fatigue, and improve overall operational stability across diverse applications. Â© Published under licence by IOP Publishing Ltd.