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Wyszukujesz frazę "Vijayakumar, S." wg kryterium: Autor


Tytuł:
Clique irreducibility of some iterative classes of graphs
Autorzy:
Aparna Lakshmanan, S.
Vijayakumar, A.
Powiązania:
https://bibliotekanauki.pl/articles/743328.pdf
Data publikacji:
2008
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
line graphs
Gallai graphs
anti-Gallai graphs
clique irreducible graphs
clique vertex irreducible graphs
Opis:
In this paper, two notions, the clique irreducibility and clique vertex irreducibility are discussed. A graph G is clique irreducible if every clique in G of size at least two, has an edge which does not lie in any other clique of G and it is clique vertex irreducible if every clique in G has a vertex which does not lie in any other clique of G. It is proved that L(G) is clique irreducible if and only if every triangle in G has a vertex of degree two. The conditions for the iterations of line graph, the Gallai graphs, the anti-Gallai graphs and its iterations to be clique irreducible and clique vertex irreducible are also obtained.
Źródło:
Discussiones Mathematicae Graph Theory; 2008, 28, 2; 307-321
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electrochemical reduction potential correlation of some insect antifeedant potent 2-phenothiazinyl chalcones
Autorzy:
Ranganathan, K.
Suresh, R.
Kamalakkannan, D.
Arulkumaran, R.
Sundararajan, R.
Sakthinathan, S. P.
Vijayakumar, S.
Thirumurthy, K.
Mayavel, P.
Thirunarayanan, G.
Powiązania:
https://bibliotekanauki.pl/articles/411842.pdf
Data publikacji:
2012
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
elektrochemia
potencjał redukcji
analiza korelacji
2-phenothiazenyl
chalkony
2-Phenothiazenyl chalcones
electrochemistry
reduction potential
correlation analysis
insect antifeedant activities
Opis:
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.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2012, 4; 66-75
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Infrared spectral analysis of waste pet samples
Autorzy:
Vijayakumar, S.
Rajakumar, P. R.
Powiązania:
https://bibliotekanauki.pl/articles/411833.pdf
Data publikacji:
2012
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
butelki PET
ABS
FTIR
mieszanki kompozytowe
PET bottles
FT-IR spectra
blended composites
Opis:
There are fifteen waste pet bottles and a commercial grade ABS was collected from local supplier of Chidambaram town. The ABS was used to study the mechanical properties of PET blend composites. This study was performed by FT-IR spectroscopy. From the characteristics infra-red stretching bands the mechanical properties of samples were discussed.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2012, 4; 58-65
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thionylchloride catalyzed aldol condensation: Synthesis, spectral correlation and antibacterial activities of some 3,5-dichloro-2-hydroxyphenyl chalcones
Autorzy:
Arulkumaran, R.
Vijayakumar, S.
Sundararajan, R.
Sakthinathan, S. P.
Kamalakkannan, D.
Suresh, R.
Ranganathan, K.
Vanangamudi, G.
Thirunarayanan, G.
Powiązania:
https://bibliotekanauki.pl/articles/411825.pdf
Data publikacji:
2012
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
chlorek tionylu
widma IR i NMR
korelacja Hammeta
aktywność antybakteryjna
wpływ podstawników
styrylo 3,5-dichloro-2-hydroksy fenylo ketony
thionyl chloride
styryl 3,5-dichloro-2-hydroxyphenyl ketones
IR and NMR spectra
Hammett correlation
substituent effects
antimicrobial activities
Opis:
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.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2012, 4; 17-38
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Microwave assisted synthesis, spectral studies and antimicrobial activities of some 2′,4′-difluorophenyl chalcones
Autorzy:
Vijayakumar, S.
Arulkumaran, R.
Sundararajan, R.
Sakthinathan, S. P.
Suresh, R.
Kamalakkannan, D.
Ranganathan, K.
Sathiyamoorthy, K.
Mala, V.
Vanangamudi, G.
Thirunarayanan, G.
Powiązania:
https://bibliotekanauki.pl/articles/412217.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Microwave irradiation
Aldol condensation
Hydroxyapatite
Spectral correlations
Hammett σ constants
antimicrobial activities
Opis:
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.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 9, 1; 68-86
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spectral correlations and antimicrobial activities of some 1-pyrenyl chalcones
Autorzy:
Arulkumaran, R.
Vijayakumar, S.
Sundararajan, R.
Sakthinathan, S.P.
Kamalakkannan, D.
Suresh, R.
Ranganathan, K.
Rajakumar, P.R.
Powiązania:
https://bibliotekanauki.pl/articles/411776.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
substituted styryl 1-pyrenyl ketones
UV spectra
IR spectra
NMR spectra
substituent effects
antimicrobial activities
Opis:
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.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 5; 21-38
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spectral correlations and antimicrobial activities of some (E)-N-Benzylidenepyridin-2-amines
Autorzy:
Sakthinathan, S. P.
Suresh, R.
Mala, V.
Sathiyamoorthi, K.
Kamalakkannan, D.
Ranganathan, K.
Arulkumaran, R.
Vijayakumar, S.
Sundararajan, R.
Vanangamudi, G.
Thirunarayanan, G.
Powiązania:
https://bibliotekanauki.pl/articles/412108.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Oxidative coupling Solvent-free synthesis
fly-ash
PTS
Aryl imines
IR and NMR spectra
Opis:
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.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 6; 77-90
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis, spectral correlations and antimicrobial activities of some 2-hydroxyphenyl-styrylketone
Autorzy:
Sathiyamoorthi, K.
Mala, V.
Suresh, R.
Sakthinathan, S.P.
Kamalakkannan, D.
Ranganathan, K.
Arulkumaran, R.
Sundararajan, R.
Vijayakumar, S.
Vanangamudi, G.
Thirunarayanan, G.
Powiązania:
https://bibliotekanauki.pl/articles/411660.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
solvent-free synthesis
SiO2-H3PO4
2’-hydroxyphenylchalcones
UV
IR
NMR spectra
Opis:
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.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 7, 2; 102-119
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of substituent effects and antimicrobial activities of some 2ʹ,5ʹ-dimethyl phenyl chalcones
Autorzy:
Joseph, S. J.
Kamalakkannan, D.
Arulkumaran, R.
Sakthinathan, S. P.
Suresh, R.
Sundararajan, R.
Vijayakumar, S.
Ranganathan, K.
Vanangamudi, G.
Thirunarayanan, G.
Powiązania:
https://bibliotekanauki.pl/articles/412597.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
substituted styryl 2
5ʹ-dimethyl phenyl chalcones
UV spectra
IR spectra
NMR spectra
substituent effects
antimicrobial activities
Opis:
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.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 5; 99-123
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Insect antifeedant potent halogen substituted phenyl chalcones
Autorzy:
Sundararajan, R.
Arulkumaran, R.
Vijayakumar, S.
Kamalakkannan, D.
Suresh, R.
John, J. S.
Ranganathan, K.
Sakthinathan, S. P
Vanangamudi, G.
Thirunarayanan, G.
Powiązania:
https://bibliotekanauki.pl/articles/412081.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Substituted styryl 2′,3′,4′-trichlorophenyl ketones
sulfated Titania
IR and NMR spectra
Insect antifeedant activities
Opis:
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.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 1; 67-73
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the uniqueness of $D$-vertex magic constant
Autorzy:
Arumugam, S.
Kamatchi, N.
Vijayakumar, G.R.
Powiązania:
https://bibliotekanauki.pl/articles/30148233.pdf
Data publikacji:
2014-05-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
distance magic graph
D-vertex magic graph
magic constant
dominating function
fractional domination number
Opis:
Let $G = (V,E)$ be a graph of order n and let $D ⊆ {0, 1, 2, 3, . . .}$. For $v ∈ V$, let $N_D(v) = {u ∈ V : d(u, v) ∈ D}$. The graph $G$ is said to be $D$-vertex magic if there exists a bijection $f : V (G) → {1, 2, . . ., n}$ such that for all $v ∈ V, _{∑uv∈ND(v)} f(u)$ is a constant, called $D$-vertex magic constant. O’Neal and Slater have proved the uniqueness of the $D$-vertex magic constant by showing that it can be determined by the $D$-neighborhood fractional domination number of the graph. In this paper we give a simple and elegant proof of this result. Using this result, we investigate the existence of distance magic labelings of complete $r$-partite graphs where $r ≥ 4$.
Źródło:
Discussiones Mathematicae Graph Theory; 2014, 34, 2; 279-286
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spectral correlation analysis and antimicrobial activities of some 2,4-dimethoxy phenyl chalcones
Autorzy:
Joseph, S. J.
Arulkumaran, R.
Kamalakkannan, D.
Sakthinathan, S. P.
Sundararajan, R.
Suresh, R.
Vijayakumar, S.
Ranganathan, K.
Kalyanasundaram, N.
Vanangamudi, G.
Thirunarayanan, G.
Powiązania:
https://bibliotekanauki.pl/articles/412661.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
substituted styryl 2
4-dimethoxy phenyl ketones
UV spectra
IR spectra
NMR spectra
substituent effects
antimicrobial activities
Opis:
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.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 4; 48-65
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biosorption of aniline blue from aqueous solution using a novel biosorbent Zizyphus oenoplia seeds: Modeling studies
Autorzy:
Kumar, M.
Elangovan, G
Tamilarasan, R
Vijayakumar, G.
Mukeshkumar, P. C.
Sendhilnathan, S.
Powiązania:
https://bibliotekanauki.pl/articles/778750.pdf
Data publikacji:
2015
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
aniline blue
removal
biosorption
Zizyphus oenoplia seed
modeling
Opis:
This article presents the feasibility for the removal of Aniline Blue dye (AB dye) from aqueous solution using a low cost biosorbent material Zizyphus oenoplia seeds. In this study, a batch mode experiments of the adsorption process were carried out as a function of pH, contact time, concentration of dye, adsorbent dosage and temperature. The experimental data were fitted with Freundlich and Langmuir isotherm equations. The feasibility of the isotherm was evaluated with dimensionless separation factor (RL). The kinetic data of sorption process are evaluated by using pseudo-first order and pseudo-second order equations. The mode of diffusion process was evaluated with intra-particle diffusion model. The thermodynamic parameters like change in enthalpy (ΔHº); change in entropy (ΔSº) and Gibbs free energy change (ΔGº) were calculated using Van’t Hoff plot. The biosorbent material was characterized with Fourier Transform Infrared (FTIR) spectroscopy and the morphology was identified with Scanning Electron Microscope (SEM) in before and after adsorption of AB dye.
Źródło:
Polish Journal of Chemical Technology; 2015, 17, 3; 70-77
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Floral morphology and HPTLC fingerprint profile of Saraca asoca (Roxb.) De Wilde (Caesalpiniaceae): A consecrated tree of India
Autorzy:
Mishra, S.B.
Vijayakumar, M.
Powiązania:
https://bibliotekanauki.pl/articles/11140.pdf
Data publikacji:
2015
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Opis:
Pharmacognosy of the flowers of Saraca asoca (Roxb.) De Wilde has been carried out to lay down standards for the genuine drug Ashoka with the detailed anatomy of various floral appendages. The aim of the present study is to determine the physico-chemical profile, preliminary phytochemical screening, fluorescence analysis and chemical composition by HPTLC of the medicinally important plant Saraca asoca. These observations would be of immense value in the botanical identification and standardization of the drug in crude form. This study would help distinguish the drug from its other species.
Źródło:
International Letters of Natural Sciences; 2015, 43
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and correlation analysis of spectral data of some (E)-2-benzylidenehydrazine carbothioamides
Autorzy:
Vijayakumar, R.
Rajarajan, M.
Balaji, S.
Manikandan, V.
Senbagam, R.
Vanangamudi, G.
Thirunarayanan, G.
Powiązania:
https://bibliotekanauki.pl/articles/1194021.pdf
Data publikacji:
2015
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Benzaldehyde
Hydrazones
IR & NMR spectral data and substituent effect
Thiosemicarbazide
UV-Vis
Opis:
A series containing ten substituted (E)-2-benzylidenehydrazinecarbothioamide were synthesized by condensation between thiosemicarbazide and various substituted benzaldehydes. The synthesized (E)-2-benzylidenehydrazinecarbothioamide were characterized by their physical constants and spectral data. The UV C=N λmax (nm), infrared ν C=N (cm-1), 1H NMR δ (CH= N) and 13C δ (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.
Źródło:
World Scientific News; 2015, 9; 70-87
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł

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