Abha Bhatnagar - Academia.edu (original) (raw)

Papers by Abha Bhatnagar

Journal of Molecular Liquids, Jul 1, 1988

Abstract Measurements of dielectric constant (e′) and loss (e″) have been made at five different ... more Abstract Measurements of dielectric constant (e′) and loss (e″) have been made at five different microwave frequencies from 1000 MHz to 67.7 GHz for acetophenone, benzophenone and propiophenone in four different non-polar solvents namely benzene, cyclohexane, 1-4-dioxane and n-heptane. Results are reported at five different temperatures from 25°C to 60°C. The dielectric data of these ketones in different solvents are analysed in terms of the Cole-Cole arc plots and superposition of two Debye-type absorptions. Values of mean relaxation times (τ o ), dipolement (μ), overall relaxation time (τ 1 ) and group relaxation time (τ 2 ) have been obtained and presented here. The values of relaxation time and dipolemoment are in reasonable good agreement, at the temperatures, at which there are available known data.

Recueil des Travaux Chimiques des Pays-Bas, Sep 2, 2010

Measurements of the static dielectric constant at 10 KHz, the refractive index (using a sodium li... more Measurements of the static dielectric constant at 10 KHz, the refractive index (using a sodium light) and the complex dielectric constant at 9.34 G H z have been made for three substituted acetophenones in a dilute solution of benzene over the temperature range 30-60°C. Dielectric relaxation times T(1) and r(2) have been calculated using the single-frequency concentrationvariation method as suggested by Higasi. Comparison with a few available results indicates that ~(2) leads to relaxation times for overall molecular rotation, whereas T(1) becomes an explicit function of both inter-and intramolecular-relaxation times. r(2), as well as the distribution parameter (a), show a systematic decrease with increase in temperature. Values of the dipole moments are also reported for these acetophenones.

Canadian Journal of Chemistry, May 1, 1989

Dielectric absorption measurements are reported at radio and microwave frequencies (at six differ... more Dielectric absorption measurements are reported at radio and microwave frequencies (at six different wavelengths) for acetylacetone and benzoylacetone solutions in benzene, in a temperature range 25-60°C. Analysis of dielectric data in terms of Cole-Cole arc plots and multiple relaxation processes reveals that, at higher temperatures, overall molecular relaxation is the dominant relaxation mechanism in these P-diketones. The observed relaxation times, distribution parameters, and dipole moments are in reasonable agreement with the few data reported for some temperatures, in the literature. The activation energy parameters are also evaluated assuming dielectric relaxation to be a rate process. Molar polarization vs. weight fraction (concentration) plots show anomalous behaviour for acetylacetone.

Journal of Molecular Liquids, 1988

Recueil des Travaux Chimiques des Pays-Bas, 2010

Measurements of the static dielectric constant at 10 KHz, the refractive index (using a sodium li... more Measurements of the static dielectric constant at 10 KHz, the refractive index (using a sodium light) and the complex dielectric constant at 9.34 GHz have been made for three substituted acetophenones in a dilute solution of benzene over the temperature range 30-60 °C. Dielectric relaxation times τ(1) and τ(2) have been calculated using the single-frequency concentration-variation method as suggested by Higasi. Comparison with a few available results indicates that τ(2) leads to relaxation times for overall molecular rotation, whereas τ(1) becomes an explicit function of both inter- and intramolecular-relaxation times. τ(2), as well as the distribution parameter (α), show a systematic decrease with increase in temperature. Values of the dipole moments are also reported for these acetophenones.

Journal of Molecular Liquids, 1988

Abstract Measurements of dielectric constant (e′) and loss (e″) have been made at five different ... more Abstract Measurements of dielectric constant (e′) and loss (e″) have been made at five different microwave frequencies from 1000 MHz to 67.7 GHz for acetophenone, benzophenone and propiophenone in four different non-polar solvents namely benzene, cyclohexane, 1-4-dioxane and n-heptane. Results are reported at five different temperatures from 25°C to 60°C. The dielectric data of these ketones in different solvents are analysed in terms of the Cole-Cole arc plots and superposition of two Debye-type absorptions. Values of mean relaxation times (τ o ), dipolement (μ), overall relaxation time (τ 1 ) and group relaxation time (τ 2 ) have been obtained and presented here. The values of relaxation time and dipolemoment are in reasonable good agreement, at the temperatures, at which there are available known data.

Canadian Journal of Chemistry, 1989

Dielectric absorption measurements are reported at radio and microwave frequencies (at six differ... more Dielectric absorption measurements are reported at radio and microwave frequencies (at six different wavelengths) for acetylacetone and benzoylacetone solutions in benzene, in a temperature range 25–60 °C. Analysis of dielectric data in terms of Cole–Cole arc plots and multiple relaxation processes reveals that, at higher temperatures, overall molecular relaxation is the dominant relaxation mechanism in these β-diketones. The observed relaxation times, distribution parameters, and dipole moments are in reasonable agreement with the few data reported for some temperatures, in the literature. The activation energy parameters are also evaluated assuming dielectric relaxation to be a rate process. Molar polarization vs. weight fraction (concentration) plots show anomalous behaviour for acetylacetone. Keywords: dielectric properties, dielectric losses, relaxation times, dipole moment, dielectric absorption and dispersion, microwave measurements.

Journal of Molecular Liquids, Jul 1, 1988

Abstract Measurements of dielectric constant (e′) and loss (e″) have been made at five different ... more Abstract Measurements of dielectric constant (e′) and loss (e″) have been made at five different microwave frequencies from 1000 MHz to 67.7 GHz for acetophenone, benzophenone and propiophenone in four different non-polar solvents namely benzene, cyclohexane, 1-4-dioxane and n-heptane. Results are reported at five different temperatures from 25°C to 60°C. The dielectric data of these ketones in different solvents are analysed in terms of the Cole-Cole arc plots and superposition of two Debye-type absorptions. Values of mean relaxation times (τ o ), dipolement (μ), overall relaxation time (τ 1 ) and group relaxation time (τ 2 ) have been obtained and presented here. The values of relaxation time and dipolemoment are in reasonable good agreement, at the temperatures, at which there are available known data.

Recueil des Travaux Chimiques des Pays-Bas, Sep 2, 2010

Measurements of the static dielectric constant at 10 KHz, the refractive index (using a sodium li... more Measurements of the static dielectric constant at 10 KHz, the refractive index (using a sodium light) and the complex dielectric constant at 9.34 G H z have been made for three substituted acetophenones in a dilute solution of benzene over the temperature range 30-60°C. Dielectric relaxation times T(1) and r(2) have been calculated using the single-frequency concentrationvariation method as suggested by Higasi. Comparison with a few available results indicates that ~(2) leads to relaxation times for overall molecular rotation, whereas T(1) becomes an explicit function of both inter-and intramolecular-relaxation times. r(2), as well as the distribution parameter (a), show a systematic decrease with increase in temperature. Values of the dipole moments are also reported for these acetophenones.

Canadian Journal of Chemistry, May 1, 1989

Dielectric absorption measurements are reported at radio and microwave frequencies (at six differ... more Dielectric absorption measurements are reported at radio and microwave frequencies (at six different wavelengths) for acetylacetone and benzoylacetone solutions in benzene, in a temperature range 25-60°C. Analysis of dielectric data in terms of Cole-Cole arc plots and multiple relaxation processes reveals that, at higher temperatures, overall molecular relaxation is the dominant relaxation mechanism in these P-diketones. The observed relaxation times, distribution parameters, and dipole moments are in reasonable agreement with the few data reported for some temperatures, in the literature. The activation energy parameters are also evaluated assuming dielectric relaxation to be a rate process. Molar polarization vs. weight fraction (concentration) plots show anomalous behaviour for acetylacetone.

Journal of Molecular Liquids, 1988

Recueil des Travaux Chimiques des Pays-Bas, 2010

Measurements of the static dielectric constant at 10 KHz, the refractive index (using a sodium li... more Measurements of the static dielectric constant at 10 KHz, the refractive index (using a sodium light) and the complex dielectric constant at 9.34 GHz have been made for three substituted acetophenones in a dilute solution of benzene over the temperature range 30-60 °C. Dielectric relaxation times τ(1) and τ(2) have been calculated using the single-frequency concentration-variation method as suggested by Higasi. Comparison with a few available results indicates that τ(2) leads to relaxation times for overall molecular rotation, whereas τ(1) becomes an explicit function of both inter- and intramolecular-relaxation times. τ(2), as well as the distribution parameter (α), show a systematic decrease with increase in temperature. Values of the dipole moments are also reported for these acetophenones.

Journal of Molecular Liquids, 1988

Abstract Measurements of dielectric constant (e′) and loss (e″) have been made at five different ... more Abstract Measurements of dielectric constant (e′) and loss (e″) have been made at five different microwave frequencies from 1000 MHz to 67.7 GHz for acetophenone, benzophenone and propiophenone in four different non-polar solvents namely benzene, cyclohexane, 1-4-dioxane and n-heptane. Results are reported at five different temperatures from 25°C to 60°C. The dielectric data of these ketones in different solvents are analysed in terms of the Cole-Cole arc plots and superposition of two Debye-type absorptions. Values of mean relaxation times (τ o ), dipolement (μ), overall relaxation time (τ 1 ) and group relaxation time (τ 2 ) have been obtained and presented here. The values of relaxation time and dipolemoment are in reasonable good agreement, at the temperatures, at which there are available known data.

Canadian Journal of Chemistry, 1989

Dielectric absorption measurements are reported at radio and microwave frequencies (at six differ... more Dielectric absorption measurements are reported at radio and microwave frequencies (at six different wavelengths) for acetylacetone and benzoylacetone solutions in benzene, in a temperature range 25–60 °C. Analysis of dielectric data in terms of Cole–Cole arc plots and multiple relaxation processes reveals that, at higher temperatures, overall molecular relaxation is the dominant relaxation mechanism in these β-diketones. The observed relaxation times, distribution parameters, and dipole moments are in reasonable agreement with the few data reported for some temperatures, in the literature. The activation energy parameters are also evaluated assuming dielectric relaxation to be a rate process. Molar polarization vs. weight fraction (concentration) plots show anomalous behaviour for acetylacetone. Keywords: dielectric properties, dielectric losses, relaxation times, dipole moment, dielectric absorption and dispersion, microwave measurements.