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1
Content available remote Wear characterization of HNT filled glass-epoxy composites using Taguchi’s design of experiments and study of wear morphology
Ravichandran G., Rathnakar G., Santhosh N., Suresh R.
Composites Theory and Practice
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2020
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R. 20, nr 2
85--91
EN
Glass-epoxy composites are increasingly being used in several industrial applications, viz. automobile, marine, aerospace, electrical and electronics components, especially in tribological components, viz. bearings, impellers, cams, driving wheels, bolts, nuts, seals, bushes and gears, which are used extensively in machinery because their lower weight, exceptional strength, resistance to corrosion capabilities, and cost effectiveness. The work focuses on optimization of the process parameters of the dry sliding wear test, viz. the applied load, disc rotation speed, weight percentage (wt.%) of the Halloysite nanotube (HNT) filler, time as well as the track diameter to minimize the wear rate of the glass fabric reinforced epoxy composite against EN-32 steel. In this research, the specimens are fabricated in accordance with the ASTM G-99 standard and the experiment is carried out with various combinations of parameters using a pin-on-disc tribometer, while keeping the time and track diameter constant. To proceed further, trial runs are conducted using MINITAB 19 software to optimize the process parameters for minimum wear by developing Taguchi’s design of experiments (DOE) based on the L45 orthogonal array (OA), and subse-quent analysis of the signal-to-noise (S/N) ratio. The results of the optimization clearly indicate that the wt.% of HNT is the most significant parameter that has a significant effect on minimizing the applied load, speed and sliding wear rate. In over-view, the experiment results showed that the combined parameters influenced the wear. In addition, scanning electron microscopy (SEM) is performed to study the surface morphologies of the worn specimens and determine the wear mechanism in accordance with the test results. The wear mechanism clearly indicates that there is a larger amount of matrix debris, fiber breakage and fiber-matrix debonding in the neat composites as compared to the HNT filled glass-epoxy composites since a distinct pattern of micro coring and segregation of the filler along the peripheries of the glass fiber-epoxy interstitial sites, leading to strong bonding between the fibers and matrix are observed in the HNT filled composites. The strong bonding thus resists the wear to a certain extent, and the wear debris is relatively less in the HNT filled composites as compared to the neat composites.
2
Content available (E)-N-substitutedbenzylidene-4-methoxyanilines as Insect Antifeedants
Lakshmanan K., Sekar K. G., Sathiyendiran V., Suresh R.
International Letters of Chemistry, Physics and Astronomy
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2015
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Vol. 41
118--123
EN
Some substituted aryl Schiff’s bases[(E)-N-substitutedbenzylidene-4-methoxyanilines] have been prepared and their purities were checked by their physical constants and spectroscopic data reported earlier. The insect antifeedant activities of these Schiff’s bases have been studied by leafdiscs bio assay method using 4th instar larvae Achoea Janata L.
3
Content available Spectral correlations in some substituted styryl (E)-4-((2-oxopropyl) diazenyl) benzoic acids
Sathiyendiran V., Sekar K. G., Thirunarayanan G., Arulkumaran R., Sundararajan R., Kamalakkannan D., Suresh R., Manikanadan V., Vijayakumar R., Vanangamudi G.
International Letters of Chemistry, Physics and Astronomy
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2014
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Vol. 11, iss. 1
33-43
EN
A series of titled compounds were prepared and analyzed their purities by literature method. The infrared and NMR spectral group frequencies of the compounds were assigned and correlated with Hammett substituent constants, F and R constants using single and multi linear regression analysis. From the results of statistical analysis, the effect of substituents on the above spectral frequencies was discussed.
4
Content available Spectral correlation analysis of Hammett substituent constants and biological activities of some (E)-1-(4-phenoxyphenyl)-3-phenylprop-2-en-1-ones
Kalyanasundaram N., Sakthinathan S. P., Suresh R., Kamalakkannan D., Joseph S. J., Vanangamudi G., Thirunarayanan G.
International Letters of Chemistry, Physics and Astronomy
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2014
|
Vol. 9
23--47
EN
A series of aryl chalcones have been synthesized from 4-phenoxyacetophonone with various substituted benzaldehydes. The purity of all chalcones has been checked using their physical constants and spectral data. These spectral data have been correlated with Hammett substituent constants and F and R parameters using single and multi-linear regression analysis. From the results of statistical analysis, the effect of substituents on the above spectral data has been studied. The single parameter correlation with few Hammett constants and F and R parameters gave satisfactory correlation coefficients whereas all multiple correlations gave satisfactory correlation coefficients with Resonance, Field and Swain-Lupton’s parameters. The antimicrobial activities of all chalcones have been studied using Bauer-Kirby method.
5
Content available Spectral correlation analysis and antimicrobial activities of some 2,4-dimethoxy phenyl chalcones
Joseph S. J., Arulkumaran R., Kamalakkannan D., Sakthinathan S. P., Sundararajan R., Suresh R., Vijayakumar S., Ranganathan K., Kalyanasundaram N., Vanangamudi G., Thirunarayanan G.
International Letters of Chemistry, Physics and Astronomy
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2014
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Vol. 4
48--65
EN
A series of 2,4-dimethoxy phenyl chalcones have been synthesized by Crossed-Aldol condensation of 2,4-dimethoxy phenyl and various substituted benzaldehydes. The purities of these chalcones have been checked by their physical constants, UV, IR, NMR and MASS spectral data. The spectral data of these chalcones have been correlated with Hammett sigma constants, F and R parameters using single and multi-linear regression analysis. From the results of statistical analysis, the effects of substituents on the spectral group frequencies have been discussed. The anti-microbial activities of these chalcones have been evaluated using Bauer-Kirby method.
6
Content available Insect antifeedant potent halogen substituted phenyl chalcones
Sundararajan R., Arulkumaran R., Vijayakumar S., Kamalakkannan D., Suresh R., John J. S., Ranganathan K., Sakthinathan S. P, Vanangamudi G., Thirunarayanan G.
International Letters of Chemistry, Physics and Astronomy
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2014
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Vol. 1
67-73
EN
Some 2′,3′,4′-trichlorophenyl chalcones [(E)-1-(2,3,4-trichlorophenyl)-3-(substituted phenyl)-2-propen-1-ones] have been synthesised using sulfated Titania catalyzed solvent-free aldol condensation between 2,3,4-trichloroacetophenone and substituted benzaldehydes. The purities of synthesised chalcones were checked by their analytical, physical and spectroscopic data reported in literature. The insect antifeedant activities of these chalcones have been studied using 4th instar larvae Achoea Janata L by castor leaf disc bio-assay method. The chloro substituted chalcones shows significant insect antifeedant activity.
7
Content available Assessment of substituent effects and antimicrobial activities of some 2ʹ,5ʹ-dimethyl phenyl chalcones
Joseph S. J., Kamalakkannan D., Arulkumaran R., Sakthinathan S. P., Suresh R., Sundararajan R., Vijayakumar S., Ranganathan K., Vanangamudi G., Thirunarayanan G.
International Letters of Chemistry, Physics and Astronomy
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2014
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Vol. 5
99-123
EN
Some 2ʹ,5ʹ-dimethyl phenyl chalcones have been synthesized by Crossed-Aldol condensation between 2,5-dimethyl acetophenone and various substituted benzaldehydes using catalytic amount of sodium hydroxide and ethanol. The yields of the chalcones are more than 93 %. The purities of these chalcones have been checked by their physical constants, UV, IR, NMR and MASS spectral data. The spectral data of these chalcones have been correlated with Hammett sigma constants, F and R parameters using single and multi-linear regression analysis. From the results of statistical analysis, the effects of substituents on the spectral group frequencies have been discussed. The anti-microbial activities of these chalcones have been evaluated using Bauer-Kirby method.
8
Content available Synthesis, spectral correlations and antimicrobial activities of some 2-hydroxyphenyl-styrylketone
Sathiyamoorthi K., Mala V., Suresh R., Sakthinathan S.P., Kamalakkannan D., Ranganathan K., Arulkumaran R., Sundararajan R., Vijayakumar S., Vanangamudi G., Thirunarayanan G.
International Letters of Chemistry, Physics and Astronomy
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2013
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Vol. 7, iss. 2
102--119
EN
Some 2’-hydroxyphenylchalcones have been synthesized under microwave irradiation by Claisen-Schmidt condensation between substituted 2-hydroxyacetophenone and substituted benzaldehydes using catalytic amount of SiO2-H3PO4. These chalcones were established by their physical constants and spectroscopic data published earlier. The UV, IR, 1H NMR and 13C NMR spectral data of these chalcone have correlated with Hammett substituent constants, F and R parameters. All the compounds have been subjected to screened for antimicrobial activity.
9
Content available Spectral correlations and antimicrobial activities of some 1-pyrenyl chalcones
Arulkumaran R., Vijayakumar S., Sundararajan R., Sakthinathan S.P., Kamalakkannan D., Suresh R., Ranganathan K., Rajakumar P.R.
International Letters of Chemistry, Physics and Astronomy
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2013
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Vol. 5
21-38
EN
A series of 1-pyrenyl chalcones have been synthesized by Crossed-Aldol condensation of 1-acetylpyrene and substituted benzaldehydes. The purities of these chalcones have been checked by their physical constants, UV, IR, NMR and MASS spectral data. The spectral data of these chalcones have been correlated with Hammett sigma constants, F and R parameters using single and multi-linear regression analysis. From the results of statistical analysis, the effect of substituents on the spectral group frequencies have been discussed. The anti-microbial activities of these chalcones have been evaluated using Bauer-Kirby method.
10
Content available Spectral correlations and antimicrobial activities of some (E)-N-Benzylidenepyridin-2-amines
Sakthinathan S. P., Suresh R., Mala V., Sathiyamoorthi K., Kamalakkannan D., Ranganathan K., Arulkumaran R., Vijayakumar S., Sundararajan R., Vanangamudi G., Thirunarayanan G.
International Letters of Chemistry, Physics and Astronomy
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2013
|
Vol. 6
77-90
EN
A series of aryl imines have been synthesized by Fly-ash: PTS catalyzed microwave assisted oxidative coupling of amines and aldehydes under solvent-free conditions. The yield of the imines has been found to be more than 90 %. The purity of all imines has been checked using their physical constants and spectral data as published earlier in literature. The UV ?maxC=N(nm), infrared ?C=N(cm-1), NMR ?(ppm) of CH=N and C=N spectral data have been correlated with Hammett substituent constants and F and R parameters using single and multi-linear regression analysis. From the results of statistical analysis, the effect of substituents on the above spectral data has been studied. The antimicrobial activities of all imines have been studied using Bauer-Kirby method.
11
Content available Microwave assisted synthesis, spectral studies and antimicrobial activities of some 2′,4′-difluorophenyl chalcones
Vijayakumar S., Arulkumaran R., Sundararajan R., Sakthinathan S. P., Suresh R., Kamalakkannan D., Ranganathan K., Sathiyamoorthy K., Mala V., Vanangamudi G., Thirunarayanan G.
International Letters of Chemistry, Physics and Astronomy
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2013
|
Vol. 9, iss. 1
68-86
EN
Some 2′,4′-difluorophenyl chalcones have been synthesized under microwave irradiation using aldol condensation between 2,4-difluoroacetophenone and substituted benzaldehydes using catalytic amount of hydroxyapatite. The yields of the chalcones are more than 85 %. The purities of these synthesized chalcones were examined by their physical constants and spectroscopic data. The UV absorption maxima (λmax, nm), infrared stretches (ν, cm-1) of CO, fingerprint region of CHip/op, CH=CHop, C=Cop modes, NMR chemical shifts (δ, ppm) of vinyl proton, carbon and carbonyl carbons have been assigned and correlated with Hammett substituent constants, F and R parameters using single and multi-regression analysis. From the statistical analysis the effect of substituent on the above spectral frequencies can be discussed. The antimicrobial activities of these synthesized chalcones have been screened using Bauer-Kirby method.
12
Content available Thionylchloride catalyzed aldol condensation: Synthesis, spectral correlation and antibacterial activities of some 3,5-dichloro-2-hydroxyphenyl chalcones
Arulkumaran R., Vijayakumar S., Sundararajan R., Sakthinathan S. P., Kamalakkannan D., Suresh R., Ranganathan K., Vanangamudi G., Thirunarayanan G.
International Letters of Chemistry, Physics and Astronomy
|
2012
|
Vol. 4
17-38
EN
A series of substituted styryl 3,5-dichloro-2-hydroxyphenyl ketones [1-(3, 5-dichloro-2-hydroxy)- 3-phenylprop-2-en-1-one] were synthesized using thionyl chloride assisted Crossed Aldol reaction. The yields of chalcones were more than 80%. The synthesized chalcones were characterized by analytical and spectroscopic data. From the spectroscopic data the group frequencies were correlated with Hammett substituent constants, F and R parameters. From the results of statistical analysis the effect of substituents were discussed. The antibacterial activities of these chalcones have been evaluated using Bauer-Kirby method.
13
Content available Electrochemical reduction potential correlation of some insect antifeedant potent 2-phenothiazinyl chalcones
Ranganathan K., Suresh R., Kamalakkannan D., Arulkumaran R., Sundararajan R., Sakthinathan S. P., Vijayakumar S., Thirumurthy K., Mayavel P., Thirunarayanan G.
International Letters of Chemistry, Physics and Astronomy
|
2012
|
Vol. 4
66-75
EN
A series containing twelve substituted styryl 2-phenothiazenyl ketones have been synthesized. The electrochemical potentials of carbonyl and vinyl groups were measured. These potentials are correlated with Hammett substituent constants, F and R parameters. From the results of statistical analyses, the effects of substituent on the group reduction potentials have been discussed. The insect antifeedant activities of these chalcones have been studied using 4th instar larvae Achoea Janata L with castor leaf discs.
14
Content available Hybrid synchronization of n-scroll Chua and Lur’e chaotic systems via backstepping control with novel feedback
Suresh R., Sundarapandian V.
Archives of Control Sciences
|
2012
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Vol. 22, no. 3
343-365
EN
This paper investigates the backstepping control design with novel feedback input approach for controlling chaotic systems to guarantee the complete synchronization as well as the anti-synchronization of chaotic systems, viz. n-scroll Chua (K. Wallace et.al. 2001) and Lur’e chaotic systems. Our theorems on hybrid synchronization for n-scroll Chua and Lur’e (J.Suyken et.al. 1997) chaotic systems is established using Lyapunov stability theory. Based on the Lyapunov function, the backstepping control is determined to tune the controller gain based on the precalculated feedback control inputs. The backstepping scheme is recursive procedure that links the choice of a Lyapunov function with the design of a controller and guarantees global stability performance of strict-feedback chaotic systems. Since the Lyapunov exponents are not required for these calculations, the backstepping control method is effective and convenient to synchronize the chaotic systems. Mainly this technique gives the flexibility to construct a control law. Numerical simulations are also given to illustrate and validate the hybrid synchronization results derived in this paper.
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