Faculty Publications

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Publications by NITK Faculty

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A 28 nm CMOS low-noise amplifier with novel redundant noise cancellation technique beyond ultra-wideband for 6G-based wireless systems
(Elsevier GmbH, 2024) Naik, D.N.; Gorre, P.; Prasad Gupta, M.; Kumar, S.; Al-Shidaifat, A.; Song, H.
In the current scenario, almost 5G-based wireless systems have been deployed everywhere but still performance trade-offs of RF amplifiers in the sub-nanometer regime are challenging. In this work, a high-performance low-noise amplifier (LNA) is realized in a 28 nm CMOS process with a novel redundant noise cancellation technique (RnC). The proposed technique improves the noise figure (NF) beyond the ultra-wideband of a low-noise amplifier (LNA) and minimizes the trade-off in the 28 nm process. An ultra-low NF is achieved in two approaches; Firstly, a current mirror network is employed in the primary path to cancel the thermal noise of the dominant transistor of a common gate-common source (CG-CS) without an extra power supply. Secondly, an auxiliary amplifier stage is introduced here to reduce the noise which contributes to the current mirror circuit and cancels the distortion in CG-CS topology without violating the traditional noise cancellation condition. In addition, an analytical approach is followed to optimize the input impedance, gain bandwidth and noise figure. Hence, the proposed RnC LNA benefits in achieving good tradeoffs among gain, bandwidth, NF, and power consumption in 28 nm technology node. The proposed RnC LNA is analyzed and fabricated using CMOS 28 nm technology, occupying an area of 0.011 mm2. The proposed design achieves an optimum performance: nearly flat gain of 15.3 dB, minimum NF of 1.7 dB over 1.7 to 12.52 GHz, and an IIP3 of − 2.6 dBm at 6.5 GHz. The proposed LNA consumes ultra-low power consumption of 1.8 mW under the power supply of 1 V. © 2023
A new reaction coordinate to study the translocation pathway of cell-penetrating peptides across lipid bilayers: The cases of transportan-10 and penetratin
(American Institute of Physics, 2025) Mathath, A.V.; Chakraborty, D.
Translocation pathway of cell-penetrating peptides remains elusive, as it is hard to observe by experimental and theoretical studies, which limits their effective use. Furthermore, lipid dynamics influence the translocation pathway, which is often overlooked due to its slow timescale. Current studies lack the effect of multiple peptides on the translocation process. Therefore, in this work, we employ the umbrella sampling technique with a preferential lipid–peptide interaction term in the reaction coordinate to explore the translocation activity of penetratin and transportan-10 (TP10) peptides in a heterogeneous membrane. In experiments, they follow different pathways according to their concentration, but the cause of this difference is unknown. We considered single and multiple (two and four) peptide translocation processes to understand the differences. Self-aggregation process is taken into account for multiple peptides. The interaction between peptides and peptides–lipids is found to be important for a proper overview of the translocation process. Peptide translocation was found to be related to the dynamics of the lipids, which change during the translocation process, making the system complex to study. In the case of multiple penetratin translocation, the anionic lipids were found to aggregate on the positive curvature of the upper leaflet, helping fold the membrane. Lipid composition of the TP10 multiple peptide case was found random. The increased mass and size of the solute in this case helped attain a radius more than the threshold value, leading to pore formation. Free energy barriers of single TP10 and penetratin are found to be 45.4 ± 2 and 33.7 ± 0.8 kJ mol?1, respectively. © 2025 Author(s).
A Novel Single Source Bridgeless Nine-Level Switched-Capacitor-Based Quadruple Boost Inverter With Reduced Voltage Stress
(Institute of Electrical and Electronics Engineers Inc., 2024) Kumar, D.; Raushan, R.; Ahmad, M.W.; Dutta, S.
The attractiveness of switched capacitor multilevel inverters (SCMLIs) stems from their ability to operate without transformers, providing voltage-boosting capabilities, inherent capacitors' voltage balancing ability, and reduced electromagnetic interference. Recent developments in SCMLI structures make it a compelling choice among various converters for diverse applications. The evolution of these topologies is primarily influenced by factors such as the number of output voltage levels, overall voltage gain, and the simultaneous reduction of component counts and stresses on devices. To address these issues further, a novel bridgeless common neutral switched capacitor multilevel inverter has been proposed in this article. The maximum voltage stress on the devices is just half of the peak output voltage, and the total standing voltage is also lower in this inverter. It has quadruple voltage gain and inherent voltage balancing of the switched capacitors. Additionally, it can operate under various loads and modulation indexes. Moreover, the proposed inverter's leakage current can be almost zero due to the presence of the common ground (CG) feature. The nearest level pulse width control technique has been implemented to operate the proposed inverter. Comparative analysis was carried out to show the advantages of the inverter. Further, a hardware prototype of the experimental setup has been developed, and results have been analyzed and discussed to strengthen the performance of the proposed inverter. © 2013 IEEE.
A Novel Two Five-Level Double-Boost Inverters for Grid-Tied Photovoltaic Applications
(Springer, 2025) Maheswari, G.; Manjunatha Sharma, K.M.; P, P.
This paper proposes two novel five-level inverters, both featuring a common ground configuration and double-boosting capability. The common ground configuration in the proposed topologies effectively eliminates leakage current, making them ideal for grid-connected photovoltaic applications. The first proposed inverter topology consists of a single DC source, six power switches, two diodes, two capacitors, and one charging inductor. The second topology also uses a single DC source but comprises seven power switches, one diode, two capacitors, and one charging inductor. In both proposed inverter topologies, the switched capacitors automatically balance to voltages of Vdc and 2Vdc. Additionally, the charging inductor helps reduce spike currents in the capacitor charging path. These inverters offer several advantages, including a reduced component count, low per-unit total standing voltage, high efficiency, increased power density due to fewer components, reduced spike currents, and a common ground (CG) structure that entirely eliminates leakage current. The proposed inverters employ a proportional-integral (PI) controller with phase disposition pulse-width modulation (for the first converter) and staircase modulation (for the second converter). A comparative analysis of existing and proposed five-level inverters is presented, demonstrating their suitability for grid-tied photovoltaic applications through MATLAB Simulink simulations and experimental validation using Hardware-in-the-Loop (HIL). © The Author(s), under exclusive licence to Springer Nature Singapore Pte Ltd. 2025.
A Reduced Capacitance H-9 Five-Level Switched Boost Capacitor Transformerless Inverter
(Institute of Electrical and Electronics Engineers Inc., 2025) Ahmed, Md.S.; Raushan, R.; Ahmad, Md.W.
Transformerless switched capacitor-based multi-level inverters are well-known for their applications in industrial and renewable energy systems. The primary features of a switched capacitor-based transformerless inverter should be minimizing leakage current for safety and minimizing ripple current for efficiency and reliability. This brief proposes a new single-stage, single-phase, five-level H-9-based transformerless inverter for standalone PV systems. This H-9 inverter, utilizes nine switches to produce the desired output voltage levels. It achieves boost functionalities by combining the switched capacitor (SC) unit with the switched boost (SB) unit in a single design. This topology effectively mitigates the leakage current by virtually grounding the load terminal through the filter capacitor. Furthermore, the ripple current of the capacitors in the switched-capacitor unit is minimized, and it is inherently balanced. To this end, the feasibility of utilizing the modulation technique for control is demonstrated, and the relevant results are experimentally validated using a laboratory prototype of the proposed converter. © 2004-2012 IEEE.
A review on analysis of biochar produced from microwave-assisted pyrolysis of agricultural waste biomass
(Elsevier B.V., 2023) Ramesh, R.; Surya, D.V.; Sankar Rao, C.S.; Yadav, A.; Sridevi, V.; Remya, N.
Every year the agricultural product processing industries produce large quantities of agricultural waste biomass (AWB). Whose disposal has become a serious issue concerning solid waste management due to environmental and health issues. Microwave-assisted pyrolysis (MAP) is an intriguing technology for producing valuable products from waste feedstocks. AWB is converted into a valuable product like biochar by using MAP. The conversion of AWB into biochar by MAP is influenced by several factors such as type of feedstock, pyrolysis temperature, residence time, pressure, heating rate, susceptor, particle size, and microwave power. However, no review article is available to understand the role of MAP on biochar production from AWB. The current review focused on understanding the fundamentals of biochar production. It also reviews the challenges in producing biochar process by compatible, acceptable, and sustainable and its future directions to gain economic benefits even at small-scale applications. The generation of biochar from MAP and its uses in agriculture are discussed. The current review would address the knowledge gap and highlight the critical implications in biochar production and applications. © 2023 Elsevier B.V.
Accelerating randomized image secret sharing with GPU: contrast enhancement and secure reconstruction using progressive and convolutional approaches
(Springer, 2024) Holla, M.; Suma, D.; Pais, A.R.
Image Secret Sharing (ISS) is a cryptographic technique used to distribute secret images among multiple users. However, current Visual Secret Sharing (VSS) schemes produce a halftone image with only 50% contrast when reconstructing the original image. To overcome this limitation, the Randomized Image Secret Sharing (RISS) scheme was introduced. RISS achieves a higher contrast of 70% when extracting the secret image but comes with a high computational cost. This research paper presents a novel approach called Graphics Processing Unit (GPU)-based Randomized Image Secret Sharing (GRISS), which utilizes data parallelism within the RISS pipeline. The proposed technique also incorporates an Autoencoder-based Single Image Super-Resolution (ASISR) to enhance the contrast of the recovered image. The performance of GRISS is evaluated against RISS, and the contrast of the ASISR images is compared to current benchmark models. The results demonstrate that GRISS outperforms state-of-the-art models in both efficiency and effectiveness. © The Author(s) 2024.
Ag2Cu2O3 Nanorods as Electrocatalysts for Hydrogen Production and Overall Water Splitting
(American Chemical Society, 2025) Kumar, A.; Hegde, A.P.; Puttur, M.; Gangadharappa, L.S.; Hosakoppa, N.S.
In this research, a series of Ag2Cu2O3 nanorods as electrocatalysts were prepared with three different drying temperatures (namely, W - 50, W - 80, and W - 120), utilizing a regular coprecipitation approach. These nanorods’ surface morphology and structural attributes were thoroughly characterized using Field Emission Scanning Electron Microscopy and High-Resolution Transmission Electron Microscopy, while X-ray diffraction provided insight into their crystal structures. The compositional analysis was accomplished via X-ray photoelectron spectroscopy and Raman spectroscopy. The W - 50 catalyst exhibited the most promising electrochemical response among the synthesized samples. In the solution of 1 M KOH, at a current density of 10 mA cm-2, it demonstrated modest overpotential values and Tafel slopes of 81 and 97 mV dec-1 for the hydrogen evolution reaction (HER), whereas 409 and 140 mV dec-1 for the oxygen evolution reaction (OER). When tested with a two-electrode electrolyzer, W - 50 serving as together the anode and cathode, a trivial cell voltage of 1.9842 V was required to accomplish a current density of 100 mA cm-2, with surprising stability over 50 h of continuous operation at 200 mA cm-2 for overall water splitting. Additionally, W - 50 displayed excellent performance for HER; it necessitated an overpotential of 337 mV to accomplish an extreme current density of 800 mA cm-2. This inquiry provides precious perceptions into the importance of confined spaces within transition metal oxide-based catalysts, advancing their application in electrocatalysis. © 2025 American Chemical Society.
An Improved Noise Reduction Technique for Enhancing the Intelligibility of Sinewave Vocoded Speech: Implication in Cochlear Implants
(Institute of Electrical and Electronics Engineers Inc., 2023) Poluboina, V.; Pulikala, A.; Pitchaimuthu, A.N.P.
A cochlear implant (CI) is the most suitable option for individuals with severe profound hearing loss. CI restores the audibility to near perfection and offers good speech understanding in quiet. However, the speech perception in noise with CIs is less optimal as most speech coding strategies of CIs encode only the temporal envelope. Besides the current CI signal coding strategies lacks sophisticated pre-processing. In the current study, we proposed a novel pre-processing method to improve speech Intelligibility in noise and tested using the acoustic simulations of cochlear implants. The proposed noise reduction technique aims to minimize the mean square error (MSE) between the temporal envelopes of the enhanced speech and its clean speech. Therefore, the proposed method will be suitable for CI applications. This paper provides an analysis of the theoretical derivation of the noise suppression function and also the performance evaluation using objective and subjective tests. The effectiveness of the proposed method was objectively evaluated using the SRMR-CI and ESTOI. Additionally, speech recognition through the acoustic simulations of the cochlear implant was done for the subjective evaluation. Performance of the proposed method was compared with the Weiner filter (WF) and sigmoidal functions. The sinewave vocoder was used to simulate the cochlear implant perception. Both objective and subjective scores revealed that the performance of the proposed technique is superior to the WF and sigmoidal function. © 2013 IEEE.
Analysing the constraints of circular economy models and policy challenges in waste management
(Inderscience Publishers, 2024) Jena, P.R.
The exponential growth in the production of goods in the last few decades has raised concerns about ecological degradation. The current design of the linear structure of the industries would create an uneven balance between natural resources and technological advances. There has been a surge of research regarding a paradigm-altering structure to industries that is known as – circular economy (CE). The CE structure aims to convert the ‘take-make-dispose’ pattern of production and consumption. However, there is less understanding regarding its specific components. This paper reviews the results of the existing studies on CE and proposes solutions. The analysis is based on three thematic areas such as challenges in implementing CE models, public policy on CE, and the limitations of CE models. The major challenges for CE models stem from a lack of precise information on the costs, benefits, and technical knowledge of the circular use of resources. © © 2024 Inderscience Enterprises Ltd.
Analysis of Fluid Flows in Bounded Domain with Particular Shape of a Cavity using Lattice Boltzmann Method
(Bentham Science Publishers, 2023) Shetty, V.V.; Balashanker, K.; Arumuga Perumal, A.P.; Patel, V.U.
The present work numerically models the incompressible, continuous phase, viscous flow of Newtonian fluid flow in a bounded domain of two-dimensional cavity that is driven by walls and contains grooves in the shape of squares on the lower wall. With the help of the mesoscopic lattice Boltzmann method (LBM) and D2Q9 square lattice model, simulation results are found stable and reliable. The flow physics of the problem by varying Reynolds number, the height and quantity of lower wall grooves, and other fluid flow characteristics within the bounded domain are studied in detail. It is seen that the effects of the groove heights and wavelengths on the fluid flow are structured within the bounded domain. The study is performed from low Re = 100 to high Re = 3200, with minimum two and maximum four-wavelength grooves evaluated on the bottom surface, each having a height of low 0.25 and high 0.75. Additionally, a thorough discussion of complicated vortex dynamics is provided regarding the input parameters and geometry. Objective: The current study aims to use mesoscopic LBM to analyze incompressible viscous fluid flows on complex geometries other than rectangular shapes. Methods: Mesoscopic approach of kinetic theory-based Lattice Boltzmann method (LBM) is implemented in the current work. The popular Single Relaxation Time Lattice Boltzmann method with D2Q9 square lattice model and second-order accurate boundary condition is adopted for the current study. Results: The numerical approach of LBM is used to simulate fluid flows in a 2D bounded domain with grooved bottom surfaces. The influence of different factors, such as the height of bottom-wall surface grooves, flow Reynolds number, and wavelength of these grooves on flow patterns, is then investigated. Conclusion: The numerical study of the bounded domain is considered, and the Reynolds number is varied from 100 to 3200, with two and four-wavelength grooves evaluated on the bottom surface, each having a height of 0.25 and 0.75. The impacts on the flow pattern both within and slightly above the grooves of the computational findings for different Reynolds numbers, groove heights, and groove wavelengths are evaluated. As the Reynolds number rises, the mixing phenomenon of fluid is shown to flow more quickly in the wall-driven enclosures. © 2023 Bentham Science Publishers.
Buckling and free vibrations behaviour through differential quadrature method for foamed composites
(Elsevier B.V., 2023) Duryodhana, D.; Waddar, S.; Bonthu, D.; Jeyaraj, P.; Powar, S.; Doddamani, M.
The current work focuses on predicting the buckling and free vibration frequencies (fn) of cenosphere reinforced epoxy based syntactic foam beam under varying loads. Critical buckling loads (Ncr) and fn are predicted using the differential quadrature method (DQM). Ncr and fn have been calculated for beams of varying cenosphere volume fractions subjected to axial load under clamped-clamped (CC), clamped-simply (CS), simply-simply (SS), and clamped-free (CF) boundary conditions (BC′s). Upon increasing the cenosphere volume fraction, Ncr and fn of syntactic foam composites increases. These numerical outcomes are compared with the theoretical values evaluated through the Euler-Bernoulli hypothesis and further compared with experimental outcomes. Results are observed to be in precise agreement. The results of the DQM numerical analysis are given out for the different BC′s, aspect ratios, cenosphere volume fractions, and varying loads. It is perceived that depending on the BC′s, the type of axial varying loads and aspect ratios has a substantial effect on the Ncr and fn behaviour of the syntactic foam beams. A comparative study of the obtained results showed that the beam subjected to parabolic load under CC boundary conditions exhibited a higher buckling load. © 2023 The Authors
Carbon Nanotube-Supported Vanadium Substituted Phospho-Molybdate Nanohybrid for Supercapacitor Applications
(John Wiley and Sons Inc, 2025) Biradar, B.R.; Swetha, M.T.; Thathron, N.; Puniyanikkottil, M.A.; Hanchate, A.; Das, P.P.; Mal, S.S.
Owing to the depletion of conventional energy sources, our civilization is slowly transitioning to renewables. Therefore, designing effective energy storage systems is one of the most pressing technical demands. The quest for improved energy and power densities in energy storage devices, particularly those with long cycle life, has pushed the investigation of novel materials intended to build effective supercapacitors. In this work, nanohybrid materials are synthesized using a hydrothermal technique by mixing carbon nanotubes and a polyoxometalate cluster, H4[PVMo11O40].xH2O. Henceforth, this complex is acronymed as CNT-PVMo11. Further, electrochemical analysis of CNT-PVMo11 nanohybrid is carried out to examine various characteristics of the supercapacitor cell made with this nanohybrid. The cyclic voltammetry confirms the diffusive-dominant charge-storage process, quantifying a 72.83% diffusion mechanism at a scan rate of 1 mV s?1. The galvanostatic charge–discharge analysis of CNT-PVMo11 nanohybrid material showed a specific capacitance of 229.35 F g?1 with energy and power densities of 31.85 Wh kg?1 and 2000 W kg?1, respectively, at 1 A g?1 current density. The electrode material also shows 90% capacitance retention even after 6000 cycles at 8 A g?1 current density, indicating the material's remarkable stability. The high specific capacitance, excellent energy density, and impressive cycling stability of the hybrid material make it a promising candidate for next-generation supercapacitor electrodes. © 2025 Wiley-VCH GmbH.
Cerium doping of FeS2 for the effective hydrogen evolution reaction (HER) electrocatalysis
(Taylor and Francis Ltd., 2025) Hegde, A.P.; Gonde, A.; Kumawat, A.; Mukesh, P.; Lakshmisagar, G.; Kumar, A.; Nagaraja, H.S.
Crafting and developing nanostructured electrocatalyst materials that are both active and stable plays a pivotal role in the shift toward economically viable hydrogen production through electrochemical water splitting, paving the way for the future replacement of fossil fuels. Such materials need to be cost-effective, simple to produce, and durable. In this context, the current research delves into improving the hydrogen evolution reaction (HER) electrocatalytic performance by incorporating cerium (Ce) into iron disulfide (FeS2) catalysts, using an uncomplicated hydrothermal fabrication approach. The study systematically examines the effects of various Ce doping levels on electrocatalytic activity. Notably, the catalyst with 15% Ce doping demonstrated exceptional efficiency, reducing the overpotential to 369 mV at 100 mA cm?2 current density. This enhanced performance can be attributed to the reduction in total charge-transfer resistance and a significant increase in the electrochemical active surface area (ECSA). Furthermore, the durability assessment of the 15% Ce-doped sample revealed its ability to sustain its catalytic activity for over 100 h under a continuous HER operation at 300 mA cm-2, with low performance-falloff. These results highlight the potential of Ce-dopping of FeS2 catalysts as a formidable choice for achieving efficient and long lasting HER electrocatalysis. © 2025 Taylor & Francis Group, LLC.
Comparative study on low velocity impact behavior of natural hybrid and non hybrid flexible thermoplastic based composites
(SAGE Publications Ltd, 2023) Kumbhare, K.; Mahesh, V.; Joladarashi, S.; Kulkarni, S.M.
The current study attempts to evaluate the low-velocity impact (LVI) behavior of jute and banana fiber-based hybrid and non hybrid green composites. The proposed composites are fabricated using compression moulding method with variety of positioning of layers namely jute-rubber-jute-rubber-jute (JRJRJ), banana-rubber-banana-rubber-banana (BRBRB), jute-rubber-banana-rubber-jute (JRBRJ) and banana-rubber-jute-rubber-banana (BRJRB). Thus developed composites are subjected to LVI testing using conical and hemispherical shaped impactor in drop weight impact testing machine and different impact velocities of 5 m/s, 10 m/s and 15 m/s. Based on the ability of the proposed composites to absorb energy, coefficient of restitution (CoR), energy loss percentage (ELP), and failure behaviour, the suggested flexible composites’ performances are assessed. The study reveals that JRJRJ composite exhibits better energy absorption capability and BRBRB exhibits least energy absorption capability compared to its counterparts. The damage study reveals that hemispherical impactor leads to more damage area due to its larger contact area whereas, conical impactor results in local penetration. Results reveals that inclusion of jute fiber as reinforcement results in better LVI properties compared to banana fiber. It is also clear that the presence of a compliant matrix improves energy absorption and damage resistance in flexible composites. © The Author(s) 2022.
Design and Laboratory Validation of a Grid-Interfaced Totem-Pole PFC Converter With PR Controller and Isolated Phase Modulated Converter for Solar-Powered Next-Gen EV Charging System
(China Power Supply Society, 2025) Kanimozhi, K.; Kesavan, P.K.; Nagendrappa, N.; Balasubramanian, B.
This paper proposes a stationery reference frame proportional-resonant (PR) controller for current control of grid-tied converters in an EV charger application. Since it is a viable alternative to rotational reference frame PI compensators in AC applications, the PR controller has been adopted for achieving zero steady state error without using any computationally intensive reference frame transformations. In this paper, a method to design the structure of PR controller and its coefficients according to the desired transient behaviour of AC signal amplitude in PFC converter current loop has been proposed. The importance of suggested PR controller design method is that the grid current magnitude is varying constantly based on the available PV power and battery charger levels which necessitates the controller to act in desired transient behaviour. So, by this way the impact of variation in system parameters have been completely overcome by operating the converter controllers appropriately in a solar powered EV charger system. To verify the effectiveness of the proposed controller design, extensive simulations and experimental studies are performed in a 1.5 kW EV charger system under various PV irradiances and charger power levels. The experimental results obtained from the laboratory prototype confirms the simulation findings. © 2025 China Power Supply Society. All rights reserved.
Detection of ethanol gas at room temperature by In2O3-based screen-printed films fabricated through particle-free aqueous solution combustible inks
(Institute of Physics, 2024) Vardhan, R.V.; Praveen, L.L.; Manjunath, G.; Pothukanuri, P.; Seikh, A.H.; Alnaser, I.A.; Mandal, S.
The current work investigates the room temperature ethanol gas detection capabilities of pristine, Sn-doped, Zn-doped, Sn & Zn co-doped In2O3-based screen-printed films, fabricated using particle-free aqueous solution combustible inks on glass substrates. The fabricated films were pure, polycrystalline with cubic bixbyite crystal structure, porous, and transparent (∼75 to 95%) in the visible range. Relatively high surface roughness was detected in pristine film than in doped films. Ethanol gas was detected by all the films at room temperature. Among all, the pristine film showed a relatively greater gas response at all concentrations of ethanol gas ranging from 25 ppm to 100 ppm. This superior gas response was attributed to comparatively greater oxygen vacancy concentration (OV/OL), relative area fraction of surface adsorbed oxygen (% of OA), and high surface roughness with porosity. The maximum ethanol gas response attained was ∼17 at 100 ppm concentration by the pristine film, which also demonstrated high selectivity to ethanol gas. © 2024 The Author(s). Published by IOP Publishing Ltd.
Determining the optimal composition of magnetorheological fluid for a short-stroke magnetorheological damper
(Springer, 2023) Aralikatti, S.S.; Puneet, N.P.; Kumar, H.
The current study investigates the effect of viscosity of base oil and weight fraction of carbonyl iron particles on maximum yield stress and effective damping range of a short-stroke magnetorheological damper (stroke length of 2 mm) designed for tool vibration mitigation. It is difficult to find the exact composition of magnetorheological fluid (MRF) based on the design equations, as unidentified practical parameters influence their behaviour hence, optimization by experimental techniques is necessary. Optimal composition of MRF are identified by genetic algorithm through central composite design of experiment. A validation study is conducted to cross verify the optimum values delivered by the algorithm. The damper is fitted onto lathe machine with the optimal fluid composition to evaluate its performance in controlling the tool vibration. The damper has been designed for the specific speed, feed and depth of cut however, the design procedure for developing a damper for higher/other cutting conditions can be achieved by the design scheme mentioned in this article. The vibration level of tool reduced by 28.66% and the amplitude of cutting force reduced by 68.18% indicating reduction of chatter vibration with the damper. An improved surface finish has been observed from 4.8 to 1.6 μm. © 2023, Indian Academy of Sciences.
Development of polymeric ionic poly(VBC-co-VI) nanoparticle incorporated thin film nanocomposite membranes for dye and salt rejection
(Royal Society of Chemistry, 2025) Mendonca, N.R.; Isloor, A.M.; Farnood, R.
Water is an important life-sustaining liquid. However, due to the current anthropogenic activities, this resource is diminishing. This work explores a method for the potential reuse of textile wastewater containing salts by utilization of thin film composite (TFC) membranes fabricated by means of interfacial polymerization on a macroporous membrane substrate composed of 15% polysulfone (PSf). A relatively lesser known variety of nanoparticles termed ionic polymeric nanoparticles were integrated into the dense polyamide (PA) layer. The ionic poly(VBC-co-VI) nanoparticles were synthesized in the laboratory via quaternary precipitation polymerization (QPP) of the monomers 1-vinyl imidazole (VI) and 4-vinybenzyl chloride (VBC) by the utilization of 2,2?-azobis(2-methylpropionitrile) (AIBN) as the free radical initiator in the solvent acetonitrile (ACN) in a single step. The synthesized nanoparticles existing in the PA layer improved the water permeability as well as the rejection capacity of the membranes. The fabricated membranes showed a dye rejection of 98% for Reactive Black 5 and >95% for Sunset Yellow FCF having a concentration of 100 ppm. The salt rejection for NaCl, MgCl, Na2SO4 and MgSO4 at 1000 ppm concentration was found to be 36%, >50%, 85% and 85%, respectively. © 2025 The Royal Society of Chemistry.
Development of Sustainable Jute/Epoxy Composite and Assessing the Effect of Rubber Crumb on Low Velocity Impact Response
(Taylor and Francis Ltd., 2022) Mahesh, V.; Mahesh, V.; Harursampath, D.; Joladarashi, S.; Kulkarni, S.M.
In the current study, the experimental assessment of influence of rubber crumb on the low velocity impact (LVI) behavior of jute epoxy composites are carried out using two types of impactors namely hemispherical and conical. Hand layup technique is used to fabricate the proposed composites. The rubber crumb is incorporated in the epoxy resin with 1.5 wt%, 3 wt%, and 5 wt%. Results revealed that incorporation of 3 wt% of rubber crumb resulted in better LVI response compared to its counterparts. Fractography studies revealed that inclusion of rubber crumb particles enhances the adhesion between resin and fiber, thereby increasing the energy absorption. In addition, they aid in reducing damage area and increasing penetration threshold of proposed composites. The current study’s systematic technique serves as a model for the efficient use and conversion of waste rubber crumb into usable natural fiber reinforced polymer matrix composites for LVI applications. © 2022 Taylor & Francis.