Mohamed Dallel - Academia.edu (original) (raw)

Papers by Mohamed Dallel

ETUDE DE L’EFFET DE LA TEMPERATURE D’ARRHENIUS SUR LA VISCOSITE DES SOLVANTS PURS ET MIXTES M. Da... more ETUDE DE L’EFFET DE LA TEMPERATURE D’ARRHENIUS SUR LA VISCOSITE DES SOLVANTS PURS ET MIXTES M. Dallel a, M. Hichri b, H. Hamda c, A.A. Al-Arfaj d, N.O. Alzamil d, N. Ouerfelli a,d. a) Université de Tunis El Manar, Laboratoire Biophysique et de Technologies Médicales LR13ES04, Institut Supérieur des Technologies Médicales de Tunis, 9 Avenue Dr. Zouhaier Essafi 1006 Tunis, Tunisie.; b)Université de Tunis El Manar, Faculté des Sciences de Tunis, LR01SE10, Laboratoire de Thermodynamique Appliquée, Département de Chimie, 2092 Tunis, Tunisie. c) Laboratoire d’Ingénierie Mathématique, Ecole Polytechnique de Tunisie, Université de Carthage, Rue El Khawarizmi, B.P.743, 2078 La Marsa, Tunisia. d) University of Dammam, Department of Chemistry, College of Science, P.O. Box 1982, Dammam 31441, Saudi Arabia.; abstract: Les mélanges binaires et ternaires occupent une grande place dans les domaines de Chimie Appliquée. Les grandeurs physico-chimiques des mélanges liquides sont importantes pour comp...

Among the physicochemical properties of binary liquid mixtures, viscosity is valuable tool for de... more Among the physicochemical properties of binary liquid mixtures, viscosity is valuable tool for developing theoretical models to understand the liquid state and structure. On the other hand, excess thermodynamic properties and deviations of analogous non-thermodynamic functions of liquid mixtures are fundamental for investigating different types of intermolecular interactions in these mixtures. Hence, the knowledge and prediction of physicochemical and thermophysical properties of binary liquid mixtures is of great importance for understanding and characterization of intermolecular interactions. In the same context, some models attempt to correlate shear viscosity in liquid mixtures to release information on eventual interactions, structure and peculiar behaviors.

Physics and Chemistry of Liquids

Excess properties calculated from literature values of experimental density and viscosity in N,N-... more Excess properties calculated from literature values of experimental density and viscosity in N,N-dimethylacetamide + methanol binary mixtures (from 303.15 to 318.15) K can 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 H* shows 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 main distinct behaviors separated by particular mole fractions in N,N-dimethylacetamide. In addition, we add that correlation between Arrhenius parameters reveals interesting Arrhenius temperature which is closely related to the vaporization temperature in the liquid vapor equilibrium and the limiting corresponding partial molar p...

Estimation and knowledge of transport properties of fluids are essential for heat and mass flow. ... more Estimation and knowledge of transport properties of fluids are essential for heat and mass flow. Viscosity is one of the important properties which are affected by temperature and pressure.

Supplement extended Abstract of funded Proposal research project 2014070 in Deanship of Scientifi... more Supplement extended Abstract of funded Proposal research project 2014070 in Deanship of Scientific Research of University of Dammam, Saudi Arabia.

In transport phenomena, precise knowledge or estimation of fluids properties are necessary, for m... more In transport phenomena, precise knowledge or estimation of fluids properties are 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 non linear regression analysis, 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). Empirical validations, using about 90 data set of viscosity of pure solvents studied at different temperature ranges are provided from literature, give excellent statistical correlations, thus allowing us to rewrite the Arrhenius equation using a single parameter instead of two. Then, taking some mathematical considerations, we try in the present work to suggest an empirical exponential law-type equation valid even for the very viscous fluids (Ea < 40 kJ· mol-1) and (-20 < ln(As /Pa·s)). In addition, we have tried to give some physical meaning of the proposed equation parameters. Also, the suggested model is very beneficial for engineering data since it would permit to estimate the missing parameter value, if a well established estimate of the other is readily available.

Supplement extended Abstract of funded Proposal research project 2014207 in Deanship of Scientifi... more Supplement extended Abstract of funded Proposal research project 2014207 in Deanship of Scientific Research of University of Dammam, Saudi Arabia.

2 3 Viscosité des liquides purs. 4 5 6 Introductio n  Les mélanges binaires et ternaires occupen... more 2 3 Viscosité des liquides purs. 4 5 6 Introductio n  Les mélanges binaires et ternaires occupent une grande place dans les domaines de Chimie Appliquée  La recherche, menée sur les propriétés des mélanges des liquides, a porté dans un premier temps sur la compréhension de leurs propriétés physico-chimiques. La viscosité La viscosité dynamique: La viscosité cinématique : Viscosité spécifique : Viscosité réduite : Viscosité intrinsèque : Viscosité relative :  Dans l'industrie chimique, les industries alimentaires, cosmétiques et pharmaceutiques Pour les calculs hydrauliques de transport de fluides. Pour les calculs de transfert d'énergie.  Les opérations de filtration, de pompage et de transvasement des liquides.  La pulvérisation (peintures et vernis).

Based on the same experimental data of shear viscosities and densities of DMA + Met binary mixtur... more Based on the same experimental data of shear viscosities and densities of DMA + Met binary mixtures at four different temperatures from 303.15 to 318.15 K and at atmospheric pressure Based on the same experimental data of shear viscosities and densities of DMA + Met binary mixtures at four different temperatures from 303.15 to 318.15 K and at atmospheric pressure [1], some new theoretical approaches have been reported, for improving investigations of variation of Arrhenius activation energy and derived partial molar properties versus molar fraction composition. Arrhenius parameters of pure components (DMA and Met) as a function of temperature can be estimated. Correlation between the two Arrhenius parameters for binary mixtures permits us to reveal the viscosity Arrhenius temperature which characterizes the studied binary liquid mixture and can provide information on the vaporization temperature of the isobaric liquid vapor equilibrium. Also, this correlation can give evidence of the existence of distinct composition regions with different behaviours. Thus, supposing that the activation energy is a thermodynamic magnitude, we have determined the partial molar activation energy to release individual interaction's contributions of each pure component within the mixture for each well-defined composition. Correlation between the molar quantities relative to the activation energies and the logarithm of the entropic factors of Arrhenius for DMA + Met mixtures over the temperature range can give a roughly linear behavior i.e. no observable change in curvature. This quasi-straight line behavior suggests us to make an empirical equation by introducing a new parameter T A denoted as viscosity Arrhenius temperature which characterizes each binary system. In the case of molar quantities, we consider that the Arrhenius temperature (T A ) is no longer a constant over the whole range of composition, we introduce a new concept of the Arrhenius' current temperature (T Ai ) for each pure component (i) to find its value at the two extreme positions i.e., at very high concentration and very high dilution respectively. The results derived in the studied binary system gives an interesting fact that the isobaric boiling point (T bi ) of the pure components is very close or strongly depends upon the viscosity Arrhenius' current temperature (T Ai ). In conclusion, we can ascertain that with more mathematical

Physical and chemical properties of solvent mixtures are important for understanding their thermo... more Physical and chemical properties of solvent mixtures are important for understanding their thermodynamic behavior. One of the most important considerations is that these properties may provide information about molecular interactions [1]. Excess molar volumes, viscosity deviations and excess molar Gibbs energy of activation of viscous flow in 1,2-dimethoxyethane + water binary mixtures at (303.15, 308.15, 313.15, 318.15 and 323.15) K. were calculated from experimental density and viscosity data presented in previous work [2]. Here these experimental values were used to test the applicability of the correlative reduced Redlich-Kister equation and the Herráez and Belda equations as well as their corresponding relative properties. Their correlation ability at different temperatures, and the use of appropriate numbers of parameters, is discussed for the case of limited experimental data. The relative functions are important to reduce the effect of temperature and, consequently, to revea...

Physics and Chemistry of Liquids