Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "correlations" wg kryterium: Temat


Wyświetlanie 1-7 z 7
Tytuł:
NMR Spectral correlations in some Tröger’s bases
Autorzy:
Thirunarayanan, G
Suresh, M.
Powiązania:
https://bibliotekanauki.pl/articles/412650.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
tröger’s bases
NMR spectra
hammett correlations
substituent effects
Opis:
Some Tröger’s bases have been synthesised from substituted anilines and paraformaldehyde in presence of Lewis acid catalyst such as anhydrous AlCl3, through electrophilic substitution reaction. The purities of these Tröger’s bases have been checked by their physical constants and spectroscopic data published earlier in the literature. The NMR chemical shift (δ, ppm) of methylene protons and carbon were assigned. The assigned methylene protons and carbon chemical shifts (δ, ppm) of synthesised Tröger’s bases have been correlated with Hammett substituent constants, F and R parameters using single and multi-regression analyses. From the results of statistical analyses, the effects of substituent on methylene protons and carbon were discussed.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 4; 1-11
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quantitative Evidence for Direct Effects Between Earth-Ionosphere Schumann Resonances and Human Cerebral Cortical Activity
Autorzy:
Saroka, K. S.
Persinger, M. A.
Powiązania:
https://bibliotekanauki.pl/articles/412383.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Schumann harmonics
quantitative electroencephalography
brain-ionosphere similarities
picoTesla intensities
correlations
Opis:
The multiple quantitative similarities of basic frequencies, harmonics, magnetic field intensities, voltages, band widths, and energetic solutions that define the Schumann resonances within the separation between the earth and ionosphere and the activity within the human cerebral cortices suggest the capacity for direct interaction. The recent experimental demonstration of the representations of the Schumann resonances within the spectral densities of normal human quantitative electroencephalographic (QEEG) activity suggests a casual interaction. Calculations supported by correlations between amplitudes of the global Schumann resonances measured several thousands of km away (which were nearly identical to our local measurements) and the coherence and current densities or these frequency bands between cerebral hemispheres for a large population of human QEEG measures indicate that such interaction occurs. The energies are within the range that would allow information to be exchanged between cerebral and Schumann sources. The near-identical solution for current density from the increasing human population and background vertical electric fields suggests that changes in the former might determine the degree of coherence between the Schumann resonances. Direct comparisons of local Schumann measurements and brain activity exhibited powerful intermittent coherence within the first three harmonics. Implications of the contributions of solar transients, surface temperature, and rapidly developing technologies to modify the ionosphere‟s Schumann properties are considered.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 20, 2; 166-194
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:
Synthesis and spectral studies of some N-[(E)-phenylmethylidene]benzenesulfonamides
Autorzy:
Sekar, K. G.
Thirunarayanan, G.
Powiązania:
https://bibliotekanauki.pl/articles/412358.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
N-[(E)-phenylmethylidene]benzenesulfonamides
SiO2-H3PO4
Greener synthesis
Hammett correlations
Opis:
A series of some N-[(E)-phenylmethylidene]benzenesulfonamide derivatives have been synthesised using solid SiO2-H3PO4 catalyst under solvent free conditions in microwave irradiation. The synthesised E-N-benzene sulfonilimines purities have been verified by their physical constants and spectroscopic data. The spectral frequencies are correlated with Hammett substituent constants, F and R parameters using linear regression analysis. From the results of statistical analysis the effect of substituents on the group frequencies will be discussed.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 8, 3; 249-258
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and spectral correlation study of some 3-(3,4-dichlorophenyl)-5-(substituted phenyl)-4,5-dihydro-1H-pyrazole-1-yl-ethanones
Autorzy:
Thirunarayanan, G.
Ravi, K.
Powiązania:
https://bibliotekanauki.pl/articles/412390.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Solvent-free cyclization cum acetylation
N-acetyl pyrazoles
IR spectra
NMR spectra
Hammett correlations
Opis:
Some N-acetyl pyrazoles including 3-(3,4-dichlorophenyl)-5-(substituted phenyl)-4,5-dihydro-1H-pyrazole-1-yl-ethanones have been synthesised by solvent free cyclization cum acetylation of chalcones including substituted styryl 3,4-dichlorophenyl ketones using hydrazine hydrate and acetic anhydride in presence of catalytic amount of fly-ash: H2SO4 catalyst. The yield of these N-acetyl pyrazole derivatives are more than 75 %. The synthesised N-acetyl pyrazoline derivatives were characterized by their physical constants and spectral data. The infrared spectral νC=N and C=O (cm-1) frequencies, NMR chemical shifts (δ, ppm) of Ha, Hb, Hc, CH3 protons, C=N, C=O and CH3 carbons of 1-(3-(3,4-dichlorophenyl)-5-(substitutedphenyl)-4,5-dihydro-1H-pyrazole-1-yl) ethanones have been assigned and correlated with Hammett substituent constants and Swain-Lupton’s parameters using single and multi-regression analysis. From the results of statistical analyses the effect of substituents on the above group frequencies and chemical shifts of the acetylated pyrazoles were discussed.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 14; 44-57
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Solvent-free synthesis and spectral linearity of some (E)-2-(substituted benzylideneamino)-N-(3-chloro-4-fluorophenyl)-hexahydro-2H cyclopenta[b]thiophene-3-carboxamides
Autorzy:
Thirunarayanan, G.
Sekar, K. G.
Powiązania:
https://bibliotekanauki.pl/articles/412418.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Solvent-free condensation
SiO2-H3PO4
Imine-carboximido derivatives
IR and NMR spectra
Hammett correlations
Opis:
Some (E)-2-(substituted benzylideneamino)-N-(3-chloro-4-fluorophenyl)-hexahydro-2H-cyclopenta[b]thiophene-3-carboxamide derivatives have been synthesized by SiO2:H3PO4 catalyzed solvent-free condensation of 2-amino-N-(3-chloro-4-fluorophenyl)-hexahydro-2H-cyclopenta [b]thiophene-3-carboxamide and various substituted benzaldehydes in microwave irradiation. The yield of the imine-carboximido derivatives has been found to be more than 85 %. The purity of all imine-carboximido derivatives has been checked using their physical constants and spectral data. The spectral data of the imine-carboximido derivatives such as infrared ? (cm-1) of CO, NH, C-N, C-Cl, C-F, C=N, and the NMR chemical shifts (?, ppm) of NH, CH, CO and C=N have been correlated with Hammett substituent constants, F and R parameters. From the results of statistical analysis, the effects of substituent on the above spectral group absorptions have been discussed.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 8, 2; 160-174
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preheated fly-ash catalyzed cyclization ofchalcones: Synthesis of some substituted pyrazole-1-carbothioamides and spectral correlations in 3-(3,4-dichlorophenyl)-5-(substituted phenyl)-4,5-dihydro-1H-pyrazole-1 carbothioamides
Autorzy:
Thirunarayanan, G.
Sekar, K. G.
Powiązania:
https://bibliotekanauki.pl/articles/412612.pdf
Data publikacji:
2013
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Pre-heated fly-ash
solvent-free synthesis
Hammett correlations
3-(3, 4-dichlorophenyl)-5-(substituted phenyl)-4
5-dihydro-1H-pyrazole-1-carbothioamides
Opis:
Some substituted 1-thiocarbomyl pyrazolines including 3-(3,4-dichlorophenyl)-5-(substituted phenyl)-4,5-dihydro-1H-pyrazole-1-carbothioamides using solvent-free preheated fly-ash catalyzed cyclization between chalcones and thiosemicarbazide microwave irradiation. The yields of these thiocarbomyl pyrazolines are more than 80 %. The purities of these synthesised pyrazoline derivatives are checked by their physical constants and spectral data earlier reported in the literature The spectral data of these 3-(3,4-dichlorophenyl)-5-(substituted phenyl)-4,5-dihydro-1H-pyrazole-1-carbothioamides had been correlated, using single and multi-linear regression analysis.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2013, 10, 1; 18-34
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-7 z 7

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies