Browsing by Author "Sharma, S."

Now showing 1 - 20 of 22

Acoustic fingerprinting for rock identification during drilling
(Inderscience Publishers, 2014) Shreedharan, S.; Hegde, C.; Sharma, S.; Vardhan, H.
During the process of mining, it is imperative to know the type and properties of the rocks being handled. The current technology for this involves core drilling, and subsequently subjecting the drilled cores to various tests in the laboratory, to identify the rocks and establish their properties. In many cases, obtaining a sample may be cumbersome and/or non-profitable. This paper presents a novel method to monitor and evaluate the sounds produced as undesirable by-products, at the drill-bit and rock interface, to predict the type of rock being drilled. A rotary drill was fabricated in the laboratory and vertical drilling was carried out on cubical rock samples, keeping various drilling parameters constant. The results obtained are promising and reinforce that it may be possible to extend the proposed methodology in the field as well, with appropriate modifications. This method may be extrapolated further in the estimation of rock properties as well. Copyright © 2014 Inderscience Enterprises Ltd.
Analytical insights into threshold voltage behaviour of vertical linearly doped fully depleted silicon-on-insulator MOSFETs
(Institute of Physics, 2025) Sharma, S.; Goel, V.; Rawat, G.
This paper presents a novel two-dimensional (2D) analytical model for the surface potential of a vertical linearly doped (VLD) fully depleted silicon-on-insulator (FDSOI) FET. Moreover, the channel electric field and threshold roll-off are modeled using the surface potential equations. The evanescent-mode analysis method has been employed to determine the channel potential, and ATLAS TCAD is utilised to simulate the subthreshold I–V characteristics of the device. The performance of the proposed device has been compared with the calibrated FDSOI FET. The proposed device demonstrates remarkable improvements over conventional FDSOI FETs: off-state leakage current plunges from 100 nA to 12 pA, while subthreshold swing sharpens from 110 mV dec?1 to 85 mV dec?1, yielding an exceptional ON-to-OFF current ratio enhancement from 7.2 × 103 to 2.8 × 107. The linearly doped channel in the proposed device is developed using the hetero epitaxy method. The proposed device can be used in integrated circuits (ICs) for low-power applications such as laptops and mobile phones. © 2025 IOP Publishing Ltd. All rights, including for text and data mining, AI training, and similar technologies, are reserved.
Copper-graphene nanocomposite fabrication through LP-DED process: Powder preparation, characterization and printability studies
(Elsevier Ltd, 2024) Sharma, S.; Thanumoorthy, R.S.; Bontha, S.; Balan, A.S.S.
Copper and its alloys play a crucial role in various engineering applications due to their excellent conductive properties. However, their poor laser absorptivity and high conductivity make them a complex material to work with using laser additive manufacturing processes, hindering the ease of fabrication of precise and complex geometries. To overcome this challenge, graphene-reinforced copper powders were employed to enhance laser absorptivity. With graphene addition, there was a substantial increase in the laser absorptivity. The addition of graphene improved laser absorptivity from 15 % for pure copper to ~60 % in Gr-Cu composites. However, the flowability deteriorated at higher compositions, which could result from increased specific surface area due to graphene agglomeration and its nanoscale surface. The influence of graphene on the ease of fabrication employing laser powder-directed energy deposition was evaluated with a single-track and bulk deposition. A single-track study revealed that pure copper tracks were inconsistent and exhibited poor bonding due to their poor laser absorptivity. Meanwhile, graphene?copper composite tracks displayed stable melt pools and uniform tracks, which could result from enhanced absorptivity. Geometrically sound and defect-free Gr-Cu tracks were deposited using 750 W laser power with composite powders, while pure copper tracks at 950 W laser power deposition yielded defective tracks. However, a graphene percentage above 0.1 % resulted in the formation of keyhole porosity due to a significant enhancement in laser absorption (~60 %). A similar observation was made for bulk deposition, i.e., defect-free deposition for Gr-Cu composites ?0.1 % graphene and keyhole porosities in the deposition of 0.25Gr-Cu and 0.8Gr-Cu. © 2024 The Society of Manufacturing Engineers
Crop Classification Based on Optimal Hyperspectral Narrow Bands Using Machine Learning and Hyperion Data
(Institute of Electrical and Electronics Engineers Inc., 2023) Reddy, B.S.; Sharma, S.; Shwetha, H.R.
In view of global climate change and the limited availability of cropland, crop classification plays a critical role in maintaining food security. Hyperspectral remote sensing has emerged as a valuable tool for classifying crops using detailed spectral information. To explore the potential of hyperspectral data for nationwide crop classification, the research uses the GHISACONUS library to identify Optimal Hyperspectral Narrow Bands (OHNBs) across seven Agricultural Experimental Zones (AEZ) in the USA. Principal Component Analysis (PCA) techniques are employed to identify 24 OHNBs from the data. OHNBs achieved notable accuracy rates, ranging from 75% to 91% when classifying different crop types and their growth stages. However, accuracy drops below 90% in significant cases, likely due to the limited selection of 24 OHNBs and the variation in crop phenology across the seven study areas. The research indicates that systematically selecting OHNBs based on crop phenological stages consistently achieves satisfactory classification accuracy. This approach effectively classifies crops in any Hyperion image. Overall, the study contributes significantly to our knowledge of using OHNBs for nationwide crop classification, highlighting the importance of considering phenological stages and data acquisition conditions to enhance accuracy. Â© 2023 IEEE.
Development of low-cost real-time driver drowsiness detection system using eye centre tracking and dynamic thresholding
(2020) Khan, F.; Sharma, S.
One in every five vehicle accidents on the road today is caused simply due to driver fatigue. Fatigue or otherwise drowsiness, significantly reduces the concentration and vigilance of the driver thereby increasing the risk of inherent human error leading to injuries and fatalities. Hence, our primary motive being - to reduce road accidents using a non-intrusive image processing based alert system. In this regard, we have built a system that detects driver drowsiness by real time tracking and monitoring the pattern of the driver�s eyes. The stand alone system consists of 3 interconnected components - a processor, a camera and an alarm. After initial facial detection, the eyes are located, extracted and continuously monitored to check whether they are open or closed on the basis of a pixel-by-pixel method. When the eyes are seen to be closed for a certain amount of time, drowsiness is said to be detected and an alarm is issued accordingly to alert the driver and hence, prevent a casualty. � Springer Nature Switzerland AG 2020.
Development of low-cost real-time driver drowsiness detection system using eye centre tracking and dynamic thresholding
(Springer Verlag service@springer.de, 2020) Khan, F.; Sharma, S.
One in every five vehicle accidents on the road today is caused simply due to driver fatigue. Fatigue or otherwise drowsiness, significantly reduces the concentration and vigilance of the driver thereby increasing the risk of inherent human error leading to injuries and fatalities. Hence, our primary motive being - to reduce road accidents using a non-intrusive image processing based alert system. In this regard, we have built a system that detects driver drowsiness by real time tracking and monitoring the pattern of the driverâ€™s eyes. The stand alone system consists of 3 interconnected components - a processor, a camera and an alarm. After initial facial detection, the eyes are located, extracted and continuously monitored to check whether they are open or closed on the basis of a pixel-by-pixel method. When the eyes are seen to be closed for a certain amount of time, drowsiness is said to be detected and an alarm is issued accordingly to alert the driver and hence, prevent a casualty. Â© Springer Nature Switzerland AG 2020.
Exploring the fungal protein cadre in the biosynthesis of PbSe quantum dots
(Elsevier B.V., 2017) Jacob, J.M.; Sharma, S.; Mohan Balakrishnan, R.M.
While a large number of microbial sources have recently emerged as potent sources for biosynthesis of chalcogenide quantum dots (QDs), studies regarding their biomimetic strategies that initiate QD biosynthesis are scarce. The present study describes several mechanistic aspects of PbSe QD biosynthesis using marine Aspergillus terreus. Scanning electron microscopic (SEM) studies indicated distinctive morphological features such as abrasion and agglomeration on the fungal biomass after the biosynthesis reaction. Further, the biomass subsequent to the heavy metal/metalloid precursor was characterized with spectral signatures typical to primary and secondary stress factors such as thiol compounds and oxalic acid using Fourier Transform Infra-Red Spectroscopic (FTIR) analysis. An increase in the total protein content in the reaction mixture after biosynthesis was another noteworthy observation. Further, metal-phytochelatins were identified as the prominent metal-ion trafficking components in the reaction mixture using Liquid Chromatography Mass Spectroscopic analysis (LCMS). Subsequent assays confirmed the involvement of metal binding peptides namely metallothioneins and other anti-oxidant enzymes that might have played a prominent role in the microbial metal detoxification system for the biosynthesis of PbSe QDs. Based on these findings a possible mechanism for the biosynthesis of PbSe QDs by marine A. terreus has been elucidated. © 2016 Elsevier B.V.
Fabrication of Î²-Phase PVDF/MWCNTs Nanofibers on a Flexible Substrate for Energy Harvesting Application
(Institute of Electrical and Electronics Engineers Inc., 2024) Chauhan, S.S.; Sharma, S.; Muhiuddin, M.; Rahman, M.R.
It is challenging to deposit the pristine polyvinylidene difluoride (PVDF) in Î² crystalline phase on a flexible substrate since pristine PVDF exists in the Î±-phase. This paper presents a novel formation of nanofibers membrane of PVDF in which multiwall carbon nanotubes (MWCNT) is added as the composite in PVDF for transformation from Î± to Î² phase. The PVDF/MWCNTs nanofibers is electro spun after adding carboxyl functionalized MWCNT with PVDF to form the Î² phase. The field emission scanning electron microscope (FE-SEM) is used to characterize the presence of the nanofiber's membrane. X-ray diffraction (XRD) is used to characterize the Î² phase and Fourier-transform infrared spectroscopy (FTIR) is used to detect the functionalized bonds in the formation of PVDF/MWCNTs nanofibers on a flexible Polyethylene Terephthalate (PET). The measurement of the polarization of electric field hysteresis shows good characteristics with Ps, Pr, and EC are 9.58 Î¼C/m2, 4 Î¼C/m2, and 1 MV/m, respectively. The optimized film has a high potential for application as the piezoelectric material in energy harvesting devices fabricated on a flexible PET film. Â© 2024 IEEE.
Fatigue and Modal Analysis of Pylon of Aircraft Using Metal Matrix Composites
(Springer, 2025) Sharma, S.; Joladarashi, S.
The aviation sector is working to make airplanes lighter to conserve fuel and eventually reduce overall expenses. This study presents the efforts made to decrease the weight of pylons through material composition changes. This study uses metal matrix composites instead of titanium alloy, which is often employed, to reduce weight while maintaining the structure's ideal strength. Modeling uses Dassault Systèmes products like SolidWorks®, and Abaqus®, software. Commercially accessible analytic products like Abaqus® and Ansys® software were used for the analysis. For modeling and analysis, the dimensions of the pylons and the load data are obtained from available literature sources. The model's fatigue life and modal frequency data were examined. The results were compared with accessible data from the literature and quantitatively examined for fatigue life and critical frequency. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2025.
High energy density supercapacitor based on Ag doped MoO3 nanorods on a flexible carbon cloth
(Elsevier B.V., 2025) Sharma, S.; Chauhan, S.S.; Chappanda, K.N.; Rahman, M.R.
In this study, the plain MoO3 and Ag-doped MoO3 nanorods are anchored on a flexible fibrous carbon cloth using a hydrothermal method, and their performances are thoroughly evaluated by fabricating the supercapacitors using both types of nanorods. The doped substrate shows drastic enhancement in specific capacitance which is nearly four times greater than undoped MoO3 nanorods at a current density of 0.5 mA/cm2. Additionally, the Ag doped MoO3 shows an excellent energy density of 43 µWh/cm2. The superior performance of the doped nanorods is attributed to its pseudocapacitive behaviour, higher conductivity, and improved charge kinetics at the electrode–electrolyte interface, enabling a more efficient and potential supercapacitor-based energy storage system to drive future low power flexible and wearable electronic devices. © 2024 Elsevier B.V.
Laser powder-directed energy deposition of CuCrZr using increasing LEPF approach: process development and characterization for mechanical and thermal properties
(Springer Science and Business Media Deutschland GmbH, 2025) Thanumoorthy, R.S.; Sharma, S.; Bontha, S.; Balan, A.S.S.
Laser Powder-Directed Energy Deposition (LP-DED) process offers potential scope in the fabrication of large-scale components and in the areas of remanufacturing technology. As the LP-DED process offers higher build volume and better control over the properties compared to other additive manufacturing techniques real-time critical components such as rocket nozzles, turbine blades, etc., can be fabricated. Fabrication of copper alloys using the LP-DED process is challenging due to the material’s poor laser absorptivity and unstable melt-pool dynamics. Hence, the current study focuses on developing a process map for fabricating sound CuCrZr deposits using the LP-DED process. Single-track analysis revealed that continuous and stable single tracks were achieved at low-power settings. Tracks with high power conditions exhibited keyhole porosity as a result of the vaporization of copper elements. However, low power conditions were not sufficient in the fabrication of bulk specimens as a result of variance in the cooling rate near the substrate (SS316L) and after deposition (CuCrZr). As a result, the increasing laser energy per unit feed (LEPF) approach was followed i.e., laser power of 200 W for the first three layers followed by 1000W for further layers. Fabricated samples exhibited superior density (97.5%) with no solute segregation (Cr or Zr). CuCrZr samples revealed long preferentially oriented columnar grains with < 111 > crystallographic texture extending parallel to the build direction. Tensile and thermal property testing revealed anisotropic behavior as a result of varying mean aspect ratios of the grains, dislocation density across planes, and the preferential orientation of the crystals. © The Author(s), under exclusive licence to Springer Nature Switzerland AG 2024.
Mitigating Man-in-the-Middle Attack in Digital Signature
(Institute of Electrical and Electronics Engineers Inc., 2020) Jain, S.; Sharma, S.; Chandavarkar, B.R.
We all are living in the digital era, where the maximum of the information is available online. The digital world has made the transfer of information easy and provides the basic needs of security like authentication, integrity, nonrepudiation, etc. But, with the improvement in security, cyber-attacks have also increased. Security researchers have provided many techniques to prevent these cyber-attacks; one is a Digital Signature (DS). The digital signature uses cryptographic key pairs (public and private) to provide the message's integrity and verify the sender's identity. The private key used in the digital signature is confidential; if attackers find it by using various techniques, then this can result in an attack. This paper presents a brief introduction about the digital signature and how it is vulnerable to a man-in-the-middle attack. Further, it discusses a technique to prevent this attack in the digital signature. Â© 2020 IEEE.
Multi-response optimization of the turn-assisted deep cold rolling process parameters for enhanced surface characteristics and residual stress of AISI 4140 steel shafts
(Elsevier Editora Ltda, 2020) Prabhu, P.R.; Kulkarni, S.M.; Sharma, S.
Surface and near-surface areas play an important role as far as safety and dependability ofengineering components particularly when it is subjected to fatigue loading. By applyingdiverse mechanical surface enhancement (MSE) strategies, close to surface layers can becustom-made bringing about enhanced fatigue strength. MSE methods are used to gener-ate surface hardened components without the time and energy-consuming heat treatment.Deep cold rolling (DCR) is one such method that can be employed where the mechanicalenergy induced enables surface-hardening of steels and thereby the combination of hard-ening and finishing in one single step. The objective of this work is to enhance residualstress and near-surface properties of AISI 4140 steel which is the most commonly usedmaterial in the automobile and aerospace industry. The samples were first turned and thendeep cold rolled with various process parameters. Microstructure, surface hardness, sur-face finish, fatigue life, and residual compressive stress after the treatment were examined.Response surface methodology (RSM) and desirability function approach (DFA) was used torelate the empirical relationship between the various process variables and responses andalso to determine the optimum parameter settings for better responses. Further, numericalsimulation of turn-assisted deep cold rolling (TADCR) process was done by utilizing ANSYS-LS-DYNA software to understand the state of residual stress under various treating settings.Confirmation experiments conducted with the optimum parameter setting to validate theimprovements in response and it is found that the deviation between optimum predictedand confirmatory experimental values is about 5%. © 2020 The Authors.
Multiple response optimisation of process parameters during drilling of GFRP composite with a solid carbide twist drill
(Elsevier Ltd, 2020) Bhat, R.; Mohan, N.; Sharma, S.; Dayananda Pai, D.; Kulkarni, S.M.
The article focuses on investigating the effect of operational parameters like feed and speed along with the composite material thickness on the damages caused in the glass fibre reinforced polymer (GFRP) composites during the drilling process. The GFRP composite studied in the presented work comprises E-glass fibre as the reinforcing material and the marine-grade isophthalic polyester as the binding matrix. Multiple responses considered in work comprises Peel-up delamination, push-down delamination and surface roughness. The technique for order of preference by similarity to ideal solution (TOPSIS) is used to develop the performance index and optimise the multiple response problem. Stepwise analysis of variance (S-ANOVA) is used to investigate the significance of each input parameter. The interaction effects of the variables are investigated using the response surface plots. The results indicate that the composite thickness contributes maximum towards the variance in the overall performance index (21.30%) and the optimum combination obtained using TOPSIS approach within the experimental limits for the selected GFRP is N3f1t1 with the maximum value of Pi (0.888). The regression model developed proves to have high goodness of fit with just 6.01% average error between predicted and experimental values. Â© 2019 Elsevier Ltd.
Nonce: Life Cycle, Issues and Challenges in Cryptography
(Springer Science and Business Media Deutschland GmbH info@springer-sbm.com, 2021) Sharma, S.; Jain, S.; Chandavarkar, B.R.
We all are living in the era of online processing, where the maximum of the information is available online. As the facilities of computer technology have increased, threats of losing personal and sensitive information have also increased. Cryptographic software and algorithms are good at some extent but as we all are seeing several attacks like Plaintext attack, Replay attack on Apply pay, Interleaving attack on PKMv2, etc. show us that our cryptographic software is less likely to be broken due to the weakness in the underlying deterministic cryptographic algorithms. A nonce is another attempt to improve security from these kinds of attacks. A nonce is an input value that will not repeat in a given context. Nonce use to prevent replay and interleaving attacks. Nonce also protects websites against malicious exploits that are based on Cross-Site Request Forgery (CSRF). The main aim of this paper is to introduce, What is Nonce, how it works and what are the issues and challenges in cryptography that we can solve with Nonce. Â© 2021, The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.
Performance assessment of solar PV panels under varying environmental conditions: a laboratory and field-based approach for sustainable energy in mining operations
(Springer, 2025) Tripathi, A.K.; Mangalpady, M.; Sharma, S.; Kumar, C.; Didwania, M.
This study provides a novel and comprehensive assessment of solar photovoltaic (PV) panel performance under varying environmental conditions, integrating laboratory experiments with real-world field studies to address challenges specific to mining operations. The research uniquely explores the combined effects of shading, temperature, humidity, dust deposition, and tilt angle, delivering actionable insights for optimizing PV systems in harsh conditions. Laboratory experiments demonstrated that a parallel configuration significantly minimizes power losses under partial shading, while a rise in temperature from 35 to 75 °C resulted in a notable 21.34% and 29.12% power output reduction for monocrystalline and polycrystalline panels, respectively. Furthermore, increased humidity (65.40 to 98.20%) caused a 35.82% decline in power output due to scattering effects. Field studies conducted in a surface mining environment revealed that dust accumulation led to a substantial 43.18% drop in maximum power output after 5 days, emphasizing the importance of regular cleaning. Optimal energy capture was achieved at a 15° tilt angle, aligning with the site’s latitude. These findings underscore the novelty of using combined experimental approaches and field validation to improve PV performance in mining operations. Practical recommendations, including parallel configurations to mitigate shading losses, temperature regulation strategies, and frequent cleaning protocols, are proposed to enhance the sustainability and efficiency of renewable energy systems in challenging environments. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2025.
Predictive analysis of peel up delamination in glass fibre reinforced polyester composite drilling
(Transstellar Journal Publications and Research Consultancy Private Limited (TJPRC) editor@tjprc.org, 2019) Bhat, R.; Mohan, N.; Kulkarni, S.M.; Sharma, S.
Composites are the engineering materials, comprising two constituents: reinforcing and the matrix or binder material. the composite machining, particularly, drilling is a complex process in comparison to the machining of traditionally employed engineering structural materials. Delamination is the most prevalent integrity issue in composite drilling. In the present work, the independent variables are categorized as continuous and categorical variables. Speed and feed are chosen as the continuous variables, whereas, the drill tool diameter and material thickness are considered as categorical variables. The peel up delamination is chosen as the response. The central composite design form of RSM is employed to develop the experimental design and develop the response regression model. The developed model is then validated using an additional set of small number of experiments and the degree of affirmation is determined. The standard error obtained analytically is 5.91%. The experimental mean standard error for the randomly conducted validating experiment obtained is 4.23%. The validation shows a high degree of agreement (99.75%) between the theoretical and analytical values. © TJPRC Pvt. Ltd.
Recast Layer Formation during Wire Electrical Discharge Machining of Titanium (Ti-Al6-V4) Alloy
(Springer, 2021) Pramanik, A.; Basak, A.K.; Prakash, C.; Shankar, S.; Sharma, S.; Narendranath, S.
Titanium alloys, in particularly Ti-6Al-4V alloy is used enormously in many high-tech sectors specially in aerospace industries due to its superior properties. Machining process (for example wire electrical discharge machining) to reshape this alloy affects the integrity of the newly generated surfaces. This experimental study has identified three affected layers using scanning electron microscopy on the cross section of the machined titanium (Ti-6Al-4V) alloy surface generated from wire electrical discharge machining (WEDM). This study also explained the formation mechanism of those three layers as no detail investigation is available in this area so far. It was found that the top flaky layers are formed due to the highest cooling rate at the outermost surface, which is induced due to the low thermal conductivity of the titanium alloy as well as the quenching effect because of the existence of dielectric. The recast layer is formed at a cooling rate lower than that at the outer surface, where the melted material is resolidified very quickly without having any grain boundaries. The heat-affected zone appears at a slightly different color, which does not melt but experience heat treatment during the machining process. © 2021, ASM International.
Recovery strategies for EoL solar panels: Sustainable and circular economy practices
(ICE Publishing, 2025) Tripathi, A.K.; Mangalpady, M.; Thandlam, A.K.; Sharma, S.; Jhalani, A.; Kumar, R.
The rapid expansion of solar PV technology highlights the need for sustainable End-of-Life (EoL) management to address resource scarcity and environmental sustainability. This study, aligned with SDG 7 and SDG 12, proposes an integrated EoL recycling approach combining thermal, chemical, and green methods to maximize material recovery while minimizing environmental impact. Thermal treatment delaminates panels, preserving silicon wafers and glass, followed by eco-friendly chemical treatments to recover metals like silver and aluminum. This method achieves high-purity material recovery for reuse in solar panel manufacturing and high-value products. By overcoming limitations of traditional methods and incorporating green solvents, it supports circular economy principles and offers cost-effective solutions for global solar panel waste management. Future research should focus on industrial scalability and economic feasibility to advance solar energy's role in sustainable development. © 2025 Emerald Publishing Limited: All rights reserved.
Reliability Analysis Using Bayesian Belief Network on Drone System: A Case Study
(Institute of Electrical and Electronics Engineers Inc., 2024) Das, M.; Mohan, B.R.; Ram Mohana Reddy, G.; Chhaparwal, E.; Krishna Kumar, K.; Chowdhury, S.; Sharma, S.
Ensuring the reliability of software components is of paramount importance in safety-critical systems. Grave consequences might occur if software failures in such systems. Hence, predicting software reliability is important in these systems. This research uses Bayesian Belief Network(BBN) and leverages historical failure data to find fault interdependencies, giving much more insights than methodologies like Fault Tree Analysis (FTA) and Reliability Block Diagrams (RBD). By comparing BBNs with these traditional methods, the research shows the dynamic capabilities of BBNs. BBN also shows the capability of using real-time data and machine learning together to increase the software reliability of the software components, making this system much safer. Â© 2024 IEEE.