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Messaadi A.,Center National des Recherche en science des Materiaux | Dhouibi N.,Center National des Recherche en science des Materiaux | Hamda H.,University of Carthage | Adbelkader Y.H.,Alexandria University | And 2 more authors.
Journal of Chemistry | Year: 2015

In transport phenomena, precise knowledge or estimation of fluids properties is necessary, for mass flow and heat transfer computations. Viscosity is one of the important properties which are affected by pressure and temperature. In the present work, based on statistical techniques for nonlinear regression analysis and correlation tests, we propose a novel equation modeling the relationship between the two parameters of viscosity Arrhenius-type equation, such as the energy (Ea) and the preexponential factor (As). Then, we introduce a third parameter, the Arrhenius temperature (TA), to enrich the model and the discussion. Empirical validations using 75 data sets of viscosity of pure solvents studied at different temperature ranges are provided from previous works in the literature and give excellent statistical correlations, thus allowing us to rewrite the Arrhenius equation using a single parameter instead of two. In addition, the suggested model is very beneficial for engineering data since it would permit estimating the missing parameter value, if a well-established estimate of the other parameter is readily available. Copyright © 2015 Aymen Messaâdi et al.


Marzougui H.,University of Carthage | Martin I.R.,University of La Laguna | Attia-Essaies S.,University of Carthage | Attia-Essaies S.,Center National des Recherche en science des Materiaux | And 3 more authors.
Optical Materials | Year: 2015

Eu3+ doped K2Mg(SO4)2.6H2O crystal was prepared by evaporation method at room temperature. A complete structure characterization including X-ray diffraction, Raman and infrared was carried out. The results reveal that this crystal crystallizes in a monoclinic structure and the most active phonons are associated with vibrations of molecular water and sulfate environments. On the other hand, the emission spectrum indicates that Eu3+ ions occupy two different sites. Therefore, a study about the luminescence from each local environment is presented. The emission spectra and luminescence decays of Eu3+ ions indicate than there are not energy transfer processes between both sites. © 2015 Elsevier B.V. All rights reserved.


Marzougui H.,University of Carthage | Martin I.R.,University of La Laguna | Attia-Essaies S.,University of Carthage | Attia-Essaies S.,Center National des recherche en science des Materiaux | And 3 more authors.
Optical Materials | Year: 2015

Eu3+ doped K2Mg(SO4)2{dot operator}6H2O crystal was prepared by evaporation method at room temperature. A complete structure characterization including X-ray diffraction, Raman and infrared was carried out. The results reveal that this crystal crystallizes in a monoclinic structure and the most active phonons are associated with vibrations of molecular water and sulfate environments. On the other hand, the emission spectrum indicates that Eu3+ ions occupy two different sites. Therefore, a study about the luminescence from each local environment is presented. The emission spectra and luminescence decays of Eu3+ ions indicate than there are not energy transfer processes between both sites. © 2015.


Messaadi A.,El Manar Campus University | Ouerfelli N.,El Manar Campus University | Das D.,Dinhata College | Hamda H.,Laboratoire dIngenierie Mathematique | Hamzaoui A.H.,Center National des Recherche en science des Materiaux
Journal of Solution Chemistry | Year: 2012

The study of physical properties of binary liquid mixtures is of great importance for understanding and characterizing intermolecular interactions. Similarly, some models attempt to correlate viscosity in liquid mixtures in order to illuminate interacting structures and peculiar behaviors. Grunberg-Nissan parameters for viscosity (η) in isobutyric acid + water mixtures over the entire range of mole fractions under atmospheric pressure and from 302.15 to 313.15 K were calculated from experimental dynamic viscosities presented in previous works. Many experimenters investigate physicochemical properties using various models to develop interpretations and conclusions. The present work comes within the framework of correlating different equations. Relationships between the Grunberg-Nissan and Arrhenius and Jouyban-Acree parameters for viscosity are shown in one critical binary mixture. © 2012 Springer Science+Business Media New York.


Dhouibi N.,Center National des Recherche en science des Materiaux | Dallel M.,Tunis el Manar University | Das D.,North Bengal University | Bouaziz M.,King Saud University | And 2 more authors.
Physics and Chemistry of Liquids | Year: 2015

Excess properties calculated from the experimental values of densities and viscosities have been presented in the previous work. These experimental values can also lead us to test different correlation equations as well as their corresponding relative functions. Inspection of the Arrhenius activation energy Ea and the enthalpy of activation of viscous flow ΔH* found very close values, here we can define partial molar activation energy Ea1 and Ea2 for N,N-dimethylacetamide and methanol respectively along with their individual contribution separately. Correlation between the two Arrhenius parameters of viscosity in all compositions shows existence of distinct behaviours separated by particular mole fractions of N,N-dimethylacetamide. In addition, the correlation between Arrhenius parameters reveals interesting Arrhenius temperature which is closely related to the vaporisation temperature in the liquid vapour equilibrium and the limiting corresponding partial molar properties that can permit us to estimate the boiling points of the pure components. © 2014, © 2014 Taylor & Francis.


Messaadi A.,Center National des Recherche en science des Materiaux | Salhi H.,Tunis el Manar University | Das D.,North Bengal University | Alzamil N.O.,University of Dammam | And 3 more authors.
Physics and Chemistry of Liquids | Year: 2015

Calculation of excess properties in N,N-dimethylacetamide + 2-methoxyethanol binary mixtures at (298.15, 308.15 and 318.15) K from experimental density, viscosity and sound velocity values were presented in previous work. Applications of these experimental values to test different correlation equations as well as their corresponding relative functions were also reported. Considering the quasi-equality between the Arrhenius activation energy Ea and the enthalpy of activation of viscous flow ΔH*, here we can define partial molar activation energy Ea1 and Ea2 for N,N-dimethylacetamide and 2-methoxyethanol, respectively, along with their individual contribution separately. Correlation between Arrhenius parameters reveals interesting Arrhenius temperature with a comparison to the vaporisation temperature in the liquid vapour equilibrium, and the limiting corresponding partial molar properties that can permit us to estimate the boiling points of the pure components. © 2015, © 2015 Taylor & Francis.


Das D.,Dinhata College | Messaadi A.,Tunis el Manar University | Dhouibi N.,Tunis el Manar University | Ouerfelli N.,Tunis el Manar University | Hamzaoui A.H.,Center National des Recherche en science des Materiaux
Physics and Chemistry of Liquids | Year: 2013

Calculation of excess properties in N,N-dimethylacetamide + water binary mixtures at (298.15, 308.15 and 318.15) K from experimental density, viscosity and sound velocity values were presented in previous work. Applications of these experimental values to test different correlation equations as well as their corresponding relative functions were also reported. Considering the quasi-equality between the Arrhenius activation energy Ea and the enthalpy of activation of viscous flow ΔH*, here we can define partial molar activation energy Ea 1 and Ea 2 for N,N-dimethylacetamide and water respectively along with their individual contribution separately. Correlation between the two Arrhenius parameters of viscosity in all the domains of composition shows the existence of two main distinct behaviours separated by a stabilised structure in a short range of mole fraction in N,N-dimethylacetamide from 0.2 to 0.3. We add that correlation reveals interesting Arrhenius temperature which is closely related to the vapourisation temperature in the liquid vapour equilibrium. © 2013 Taylor and Francis Group, LLC.


Marzougui H.,University of Carthage | Attia-Essaies S.,University of Carthage | Attia-Essaies S.,Center National des Recherche en science des Materiaux | Ben Hassen-Chehimi D.,University of Carthage
Journal of Molecular Structure | Year: 2016

Tutton's salts K2M(SO4)2·6H2O (M = Mg, Ni) have been synthesized by the slow evaporation method at room temperature. A complete structural characterization has been carried out by means of powder X-ray diffraction (XRD). The results indicate that the structure of these salts is monoclinic system with the space group P21/a (Z = 2). IR and Raman spectra of KMS6 (M = Mg,Ni) have been recorded and analyzed. From the spectra, the vibrations due to SO4 2- ion, the complex [M(H2O)6]2+ and the water molecules have been identified. Thermogravimetry, differential thermal analysis and XRD at high-temperature investigations show that the dehydration of these salts occurs between 300 and 500 K. This indicates the removal of all water molecules around 426 K. © 2016 Published by Elsevier B.V.

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