Browsing by Author "Sharma, A.K."

Now showing 1 - 15 of 15

Comparative study on bearing capacity of bottom ash-stabilized soil mixed with natural and synthetic fibers
(ASTM International service@astm.org, 2020) Prasannan, S.; Kolathayar, S.; Sharma, A.K.
This article assesses the strength behavior of bottom ash (BA)-stabilized soil mixed with different fibers through a series of laboratory tests. Optimum BA and fiber percentage were obtained by small scale lab tests like compaction tests and unconfined compressive strength (UCS) tests. From compaction tests with varying proportions of BA (10, 20, 30, and 40 %), the optimum BA content was found to be 30 %. With this optimum BA content, UCS tests were conducted on soil-BA mix with different fibers (coir, areca, sisal, and polyvinyl alcohol) at various percentages (0.5, 1, 1.5, and 2 %) to find the optimum fiber content. A set of model footing tests were done to check the credibility of using fibers as a strengthening material beneath footing to upgrade the engineering properties of soil to make a reasonable subsoil for the foundation. A total of six model footing tests were performed on raw soil, on soil with optimum BA content, and on BA-stabilized soil mixed with different fibers in their optimum percentage (1.5 %). The bearing capacity of unstabilized unreinforced soil was found to increase significantly with the inclusion of fibers. © © 2020 by ASTM International
Design and development of ITO/Ag/ITO spectral beam splitter coating for photovoltaic-thermoelectric hybrid systems
(Elsevier Ltd, 2017) Sibin, K.P.; Selvakumar, N.; Kumar, A.; Dey, A.; Sridhara, N.; Shashikala, H.D.; Sharma, A.K.; Barshilia, H.C.
ITO/Ag/ITO (IAI) multilayer coatings were designed for spectral beam splitter applications and these coatings were deposited on glass substrates by magnetron sputtering method. The thicknesses of the component layers, namely, Ag and ITO were varied to achieve high visible transmittance, high NIR-IR reflectance and optimum cut-off wavelength. The optimized ITO/Ag/ITO exhibits high visible transmittance (?88%) and high NIR-IR reflectance (>90%) with an optimum cut-off wavelength (?900 nm). A novel chemical etching method was used to improve the transmittance of the plain glass substrate. The optimized IAI multilayer coating deposited on single side etched glass substrate resulted in increase in transmittance (?91%), which is due to the nano-porous morphology of the etched glass substrate. The angular and polarization dependence studies of IAI multilayer coatings were also studied in detail. © 2016 Elsevier Ltd
Dielectric and piezoelectric properties of PVDF/PZT composites: A review
(John Wiley and Sons Inc, 2015) Jain, A.; Prashanth, K.J.; Sharma, A.K.; Jain, A.; P.n, R.
Smart materials, which exhibit piezoelectricity, find an eclectic range of applications in the industry. The direct piezoelectric effect has been widely used in sensor design, and the inverse piezoelectric effect has been applied in actuator design. Ever since 1954, PZT and BaTiO3 were widely used for sensor and actuator applications despite their toxicity, brittleness, inflexibility, etc. With the discovery of PVDF in 1969, followed by development of copolymers, a flexible, easy to process, nontoxic, high density alternate with high piezoelectric voltage coefficient was available. In the past 20 years, heterostructural materials like polymer ceramic composites, have received lot of attention, since these materials combine the excellent pyroelectric and piezoelectric properties of ceramics with the flexibility, processing facility, and strength of the polymers resulting in relatively high dielectric permittivity and breakdown strength, which are not attainable in a single phase piezoelectric material. The current review article is an attempt to provide a compendium of all the work carried out with reference to PVDF-PZT composites. The review article evaluates the effect of grain size, content and other factors under the purview of dielectric and piezoelectric properties while evaluating the sensitivity of the material for sensor application.
Electric vehicle intelligent monitoring and analysis for battery
(American Institute of Physics, 2024) Saxena, A.; Binod, S.; Maurya, S.; Kapoor, O.; Singh, U.; Kumar, R.; Sharma, A.K.
This article shows the intelligent monitoring of electric vehicle for battery energy management with soft computing techniques. Thereafter different soft computing techniques like fuzzy logic controller, energy hub method, dynamic programming, DRL method, model predictive control was proposed to get the best results for the performance of EV and it is observed that fuzzy logic controller gives the best results as compared to other techniques vehicle for battery energy management. Â© 2024 Author(s).
Environmental stability of transparent and conducting ITO thin films coated on flexible FEP and Kapton® substrates for spacecraft applications
(Elsevier B.V., 2018) Sibin, K.P.; Mary Esther, A.C.; Shashikala, H.D.; Dey, A.; Sridhara, N.; Sharma, A.K.; Barshilia, H.C.
Acquiring good adhesion of ITO thin films on polymer substrate is a major concern, especially for space related applications. Delamination of ITO coating on these polymers can seriously damage the spacecraft. This paper presents the development of highly transparent and conducting ITO thin films on as-received and surface treated fluorinated ethylene propylene (FEP) and Kapton® substrates by reactive direct current magnetron sputtering. Stability of the ITO coating on FEP and Kapton® substrates was studied in simulated space environments. Environmental tests such as: relative humidity, thermal cycling and thermo vacuum were performed. Thermo-optical properties and sheet resistance of ITO coated FEP and Kapton® substrates were studied before and after environmental tests. Optimized ITO coating with thickness of ~ 15 nm on FEP and Kapton® substrates showed sheet resistance in the range of 2–4 k?/sq. with high average transmittance and high IR emittance. Adhesion of ITO coating on FEP substrate was improved by Ar plasma etching. X-ray photoelectron spectroscopy and field emission scanning electron microscopic studies of etched FEP substrate showed defluorination and high roughness of the etched surface which helped for better adhesion of ITO coating. We demonstrated that ITO coated plasma etched FEP substrate showed no change in the sheet resistance and thermo-optical properties. Moreover, ITO coated etched FEP substrate showed good environmental stability than ITO coated untreated FEP substrates. © 2017 Elsevier B.V.
Highly transparent and conducting ITO/Ag/ITO multilayer thin films on FEP substrates for flexible electronics applications
(Elsevier B.V., 2017) Sibin, K.P.; Srinivas, G.; Shashikala, H.D.; Dey, A.; Sridhara, N.; Sharma, A.K.; Barshilia, H.C.
Transparent and conducting ITO/Ag/ITO (IAI) multilayer coatings were deposited on glass and flexible fluorinated ethylene propylene (FEP) substrates by reactive sputtering using metallic In:Sn (90%:10%) and Ag targets at room temperature. Middle Ag layer thickness was optimized to obtain maximum figure of merit (?) and the optimum Ag layer thickness was found to be ~13 nm. The optimized IAI multilayer on glass substrate showed transmittance of ~88.6% and sheet resistance of ~7.1 ?/sq. The transmittance increased to ~91.4% for the IAI multilayer deposited on one side etched glass. The optimized IAI multilayer coating was also deposited on flexible FEP substrates. The electrical, optical, structural and morphological properties of IAI deposited on glass and FEP substrates were compared. IAI deposited on FEP substrate showed transmittance of ~90.2% at ? = 550 nm, sheet resistance of ~6.9 ?/sq. and figure of merit of ~52 × 10?3 ??1. Bending test of IAI deposited FEP proved the high flexibility of IAI multilayer for the flexible transparent electrode applications. Solar selectivity study of IAI on FEP substrate showed it can effectively reflect the higher wavelength region of solar spectrum and can be used as a flexible solar spectrum segregator. Optical haze measurements of IAI coated glass and FEP show that high haze value can be achieved by increasing the roughness on non-coated side of the FEP substrate. © 2017
K means clustering for gene-gene interaction in episodic memory
(Serials Publications serialspublications@vsnl.net, 2016) Tripathi, S.; Sharma, A.K.; Mishra, R. B.; Pandey, B.
In this paper K means Clustering Algorithm is used for clustering of candidate genes related to human episodic memory. The clustering of genes is based on gene-gene interaction score. The clusters are supposed to be formed so that distribution of cluster as well as overall interaction Score of clusters should be better. The K-means clustering technique applied to cluster the genes such as in tool STRING 9.1 provides cluster outcome. We compare the results of K means Clustering provided by STRING 9.1 with our K means Clustering Algorithm. The results obtained using K-means shows that clusters formed have better distribution of genes. © International Science Press.
Novel application of graphite-talc hybrid nanoparticle enriched cutting fluid in turning operation
(Elsevier Ltd, 2021) Singh, V.; Sharma, A.K.; Sahu, R.K.; Katiyar, J.K.
In this study, the influence of hybrid nanocutting fluid (both graphite and talc nanoparticles dispersed in a base fluid) in turning of Titanium alloy grade 5. The hybrid nanocutting fluid was developed by the blending of graphite and talc nanoparticles in a constant volumetric proportion (50:50) in pure coconut oil as a base fluid. The prepared hybrid nanocutting fluid has been investigated for its tribological behaviour using a pin-on-disc machine. The Gray relational analysis (GRA) is applied as a conservative approach in the optimization of process variables of Titanium alloy with multiple performance characteristics. The turning performance of the hybrid nanocutting fluid is compared with that of pure coconut oil in terms of cutting force and surface roughness. From the Gray relational grade analysis, it is obtained that the feed rate has a larger influence on responses as compared to cutting speed and nanoparticle concentration as well. By the application of hybrid nanocutting fluid, it is obtained a significant reduction in cutting force and surface roughness compared to pure coconut oil by 21.19 % and 18.9 %, respectively. © 2020 The Society of Manufacturing Engineers
Optical and electrical properties of ITO thin films sputtered on flexible FEP substrate as passive thermal control system for space applications
(Elsevier, 2016) Sibin, K.P.; Swain, N.; Chowdhury, P.; Dey, A.; Sridhara, N.; Shashikala, H.D.; Sharma, A.K.; Barshilia, H.C.
ITO thin films were deposited on flexible fluorinated ethylene propylene (FEP) substrates by pulsed direct current reactive magnetron sputtering system using an In:Sn (90%-10% wt.) alloy target. The influence of the deposition parameters (argon and oxygen flow rates, and substrate temperature) and effect of coating thickness on the optical, electrical, structural and microstructural properties of ITO thin films deposited on FEP was investigated. The thickness of the ITO coatings was varied from 5 to 180 nm. The optimized ITO coating (10 nm thick) exhibited high IR emittance (79%) on FEP substrate with high average solar transmittance (94.0%) and moderate sheet resistance (3 k?/sq.). We also investigated in detail the angular dependence of reflectance as well as haze factor of thin ITO coatings. Our results suggest that 10 nm thick ITO coating exhibits an average haze factor of 8.6%. The high value of IR emittance, moderate sheet resistance and high solar transmittance along with low haze factor indicate the suitability of ITO thin films on FEP substrates as flexible optical solar reflector for space applications. © 2015 Elsevier B.V. All rights reserved.
Optical and electrical studies of sputter-deposited transparent and conducting ITO/Ag/ITO multilayer on KaptonÂ® substrate for transparent flexible electronic applications
(Elsevier Ltd, 2018) Sibin, K.P.; Srinivas, G.; Shashikala, H.D.; Dey, A.; Sridhara, N.; Sharma, A.K.; Barshilia, H.C.
Transparent and conducting thin films on flexible substrates have enormous applications in the areas of space, solar, displays, etc. We hereby report the sputter deposition of transparent and conducting ITO/Ag/ITO (IAI) thin films on commercially available flexible KaptonÂ® substrate at a lower substrate temperature. IAI multilayer has been deposited by magnetron sputtering system using an alloy In:Sn (90% :10%) and Ag targets at room temperature without breaking the vacuum. The optimized IAI coating shows high transmittance (âˆ¼81.3 % at Î³= 650 nm) along with very low resistance (8.36 Ï‰/). Optical haze value of IAI on Kapton was measured and found to be <7%. The figure of merit of IAI coating on KaptonÂ® has been calculated using the Haacke's formula Ï€ = r10/Rs. At Î³= 650 nm Ï€ = 15 Ã— 10 Ï‰ was observed. Our findings give worthful insight into the sputter deposition of transparent conducting IAI coating on flexible KaptonÂ® substrate for flexible electronics applications. Â© 2017 Elsevier Ltd. All rights reserved.
Optical and electrical studies of sputter-deposited transparent and conducting ITO/Ag/ITO multilayer on Kapton� substrate for transparent flexible electronic applications
(2018) Sibin, K.P.; Srinivas, G.; Shashikala, H.D.; Dey, A.; Sridhara, N.; Sharma, A.K.; Barshilia, H.C.
Transparent and conducting thin films on flexible substrates have enormous applications in the areas of space, solar, displays, etc. We hereby report the sputter deposition of transparent and conducting ITO/Ag/ITO (IAI) thin films on commercially available flexible Kapton� substrate at a lower substrate temperature. IAI multilayer has been deposited by magnetron sputtering system using an alloy In:Sn (90% :10%) and Ag targets at room temperature without breaking the vacuum. The optimized IAI coating shows high transmittance (?81.3 % at ?= 650 nm) along with very low resistance (8.36 ?/). Optical haze value of IAI on Kapton was measured and found to be <7%. The figure of merit of IAI coating on Kapton� has been calculated using the Haacke's formula ? = r10/Rs. At ?= 650 nm ? = 15 � 10 ? was observed. Our findings give worthful insight into the sputter deposition of transparent conducting IAI coating on flexible Kapton� substrate for flexible electronics applications. � 2017 Elsevier Ltd. All rights reserved.
State of the art on sustainable manufacturing using mono/hybrid nano-cutting fluids with minimum quantity lubrication
(Taylor and Francis Ltd., 2022) Singh, V.; Sharma, A.K.; Sahu, R.K.; Katiyar, J.K.
In machining operations, the application of cutting fluids has been of prime importance for the extraction of heat from rake surfaces, ease of removal of the chips and reduction of friction at the chip–tool interface. These three objectives are achieved by the supply of suitable conventional cutting fluid at the machining zone using different techniques. However, the misuse of these fluids and their wrong disposal methods were found to have an adverse effect on the environment and health of human. To reduce the usage of conventional cutting fluid, minimum quantity lubrication (MQL) technique has been emerged as an alternative means in the last few years, leading to better eco-friendly. Further, to increase the sustainability of MQL technique, it becomes necessary to use an appropriate exceptional nanostructured material with MQL that could be an effective cutting fluid (i.e. nanocutting fluids) with better tribological and thermophysical properties, and might be helpful in addressing the eco-friendly problem to a great extent. Therefore, the present paper focuses on the review of important published works related to the use of mono/hybrid nanocutting fluids with MQL technique at various processing parameters in different metal cutting operations. Most of the studies have shown a significant reduction in cutting forces, temperature at cutting zone, tool wear, and friction coefficient, and considerable improvement in surface quality by the addition of mono/hybrid nanoparticles enriched cutting fluid in MQL technique as compared to dry as well as wet machining processes. Further, the paper discusses the future scope in the area of hybrid nano-cutting fluids in different machining processes. © 2022 Taylor & Francis.
Strength Behavior of Rammed Earth Stabilized with Metakaolin
(Springer, 2020) Thiviya, S.K.; Krishnan, A.G.; Kalathuru, M.; Sharma, A.K.; Kolathayar, S.
Rammed earth is an ancient construction technique practiced in India and in other parts of the world. The ancient traditional technique was of the un-stabilized method but incorporating suitable stabilizing materials will improve the strength of rammed earth construction. The main objective of the present study is to assess the behavior of the rammed earth with metakaolin. The suitability of the soil was tested based on sieve analysis and followed by mini compaction tests; optimum moisture content for the rammed earth construction for the selected soil was fixed for different proportions of binders with the soil. From the compaction results, the binder content was fixed for stabilization of rammed earth. The unconfined compressive strength of the sample was found for the samples at 7, 14, 28 days of curing, and microstructural studies of the samples were performed. The compression strength of rammed earth cubes was tested and also the durability of the cubes was determined by the spray erosion test. © 2020, Springer Nature Singapore Pte Ltd.
Strength Tests and Model Experiments on Soil Reinforced with Areca and PVA Fibers
(Springer Science and Business Media Deutschland GmbH, 2020) Kolathayar, S.; Prasannan, S.; Sharma, A.K.
Uncertainties in geotechnical engineering are unavoidable. The soil properties may distribute within a significant range over a domain. The soil is often very weak in tension and has less stability under heavy loading. This paper presents stabilization of soil with bottom ash reinforcement of soil with natural or synthetic fibers. Several reinforcing materials are available in the market, but they are costly and not easily accessible. Bottom ash (BA) was used as a stabilizing agent, and areca fiber was used for reinforcement, in this study. Polyvinyl alcohol (PVA), which is a synthetic fiber, was also used to compare the performance of areca fiber. As compared to fly ash, the use of bottom ash is minimal all over the world. This study determines the strength of the soil stabilized with bottom ash and fibers at different proportions. The percentage of bottom ash was varied from 0 to 40%; fiber proportion was varied from 0 to 2%. Â© 2020, Springer Nature Singapore Pte Ltd.
XPM-induced crosstalk with higher order dispersion in SCM–WDM optical transmission link
(Elsevier GmbH journals@elsevier.com, 2012) Kumar, N.; Sharma, A.K.; Kapoor, V.
In this paper, the XPM-induced crosstalk has been evaluated with higher order dispersion in SCM–WDM optical transmission link at different modulation frequencies. It has been observed that there is exponent increase in XPM-induced crosstalk with the increase in modulation frequency from 0 to 3 GHz. The impact of 3OD, 4OD and 5OD is small as compared to 2OD but still contributes when the combined terms are considered. The combined effect of second, third, fourth and fifth-order dispersion parameters is that the induced crosstalk introduced by XPM increases. © 2011 Elsevier GmbH