Dr. Montaha Aoun
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Researches:
Popular Uses and Medical Treatments of Frankincense
Natural resins played an important role in the daily life and rituals of religious ceremonies of aromatic aroma and its various medicinal effects since ancient. Boswellia, one of the most important natural resins, is the subject of our research. The Boswellia plants are species of Saponins. They produce aromatic resins given by laticiferous ducts through a process of stripping the bark of the branches; a yellow gum is released, then frozen in natural conditions in small granules known as Boswellia resins or frankincense. Through the study of combinations and mixtures contained in some manuscripts and modern research, it was found that frankincense was used in several fields in different historical periods. It is still used in religious ceremonies in Roman Catholic, Episcopal, Orthodox and Indian churches. - Aleppo University Research Journal, Medical Science Series, N° 133.
Read More >>Alum in Pharmaceutical Products: Between the Past and the Present
- Aleppo University Research Journal, Medical Science Series, N° 128.
Read More >>Investigation of nucleation and crystal growth kinetics of nickel manganese oxalates
The nucleation and the crystal growth rates of mixed nickel manganese oxalates have been determined from the changes of the ionic concentration of the solution and the crystal size distribution during the precipitation process within a supersaturation range 0–0.1 M. Thermodynamic solubility calculations have been used to identify the different species contributing the precipitation reaction and for estimation of the thermodynamic constant. Experimental data show that the nucleation rate of mixed nickel manganese oxalate in this supersaturation range is consistent with a primary heterogeneous mechanism and was found to obey to an exponential law. The crystal growth rates indicate a surface-integration-controlled mechanism with a first-order law with respect to the supersaturation. - Journal of Crystal Growth, vol. 279, pp. 531-539
Read More >>High quality nickel manganese oxalate powders in a new segmented flow tubular reactor
High-quality nickel manganese oxalates have been prepared using an innovative approach for the production of homogeneous powders, the continuous Segmented Flow Tubular Reactor (SFTR). This new reactor is mainly composed of a mixer, a segmenter, a tubular section and a decanter. Mixed Ni–Mn oxalates are synthesized in the SFTR. The powders present controlled morphology, narrow particle size distribution, high purity and desired stoichiometry. Their characteristics are compared to those of powders obtained in a batch reactor. These oxalates are precursors for nickel manganites, used as negative temperature coefficient thermistor (NTC) ceramics. - Solid State Ionics, vol. 171, pp. 135-140, 2004
Read More >>Development of a Continuous Segmented Flow Tubular Reactor and the “Scale-out” concept – In Search of Perfect Powders
The synthesis of powders with controlled shape and narrow particle size distributions is still a major challenge for many industries. A continuous Segmented Flow Tubular Reactor (SFTR) has been developed to overcome homogeneity and scale-up problems encountered when using batch reactors. Supersaturation is created by mixing the co-reactants in a micromixer inducing precipitation; the suspension is then segmented into identical micro-volumes by a non-miscible fluid and sent through a tube. These micro-volumes are more homogeneous when compared to large batch reactors leading to narrower size distributions, better particle morphology, polymorph selectivity and stoichiometry. - Chemical Engineering Technology, vol. 26-3, pp. 303-305
Read More >>An experimental method and a Markov chain model to describe axial and radial mixing in a hoop mixer
An experimental methodology is developed to investigate the simultaneous axial and radial mixing of particles in a hoop mixer. This involves following the migration of a colored tracer, with flow properties identical to that of the bulk using tracer detection by image analysis. The particle transitions from all initial tracer positions inside the mixer are calculated and the experimental conditions are established which improve the homogeneity of the mixture. Finally, a Markov chain model is derived which gives a good representation of the experimental data. - Powder technology, vol. 128, pp. 159-167
Read More >>Mathematical model of a periodical mixer
- Mathematical model of periodical mixer, vol. 44, pp.140-141.
Read More >>A simultaneous determination of nucleation and growth rates from batch spontaneous precipitation
A review of the literature shows that many methods for determining the nucleation and growth rates from batch precipitation experiments are inaccurate. Therefore, a new method has been developed to derive these two rates based on the simultaneous measurement of the supersaturation and the crystal size distribution during a batch spontaneous precipitation. All experimental data are used without any previous numerical treatment and the differential kinetic equations are replaced by integral ones to avoid numeric derivation. The kinetic parameters of the two postulated laws of nucleation and crystal growth rates in kinetic equations are separately determined by non-linear optimization. - Chemical Engineering Science, vol. 54, pp. 1161-1180.
Read More >>Are Barium Sulphate Kinetics Sufficiently Known for Testing Precipitation Reactor Models?
Barium sulphate precipitation, widely used to validate micromixing models, requires the knowledge of nucleation and crystal growth kinetics under non stoichiometric conditions, which is generally the case when two fluids are mixed. Therefore, the spontaneous precipitation of barium sulphate was studied under both stoichiometric and non stoichiometric conditions. A new method was developed to derive the nucleation and crystal growth rates based on the simultaneous measurement of concentration and crystal size distribution. Two expressions were proposed describing well nucleation and crystal growth kinetics. The kinetic parameters were determined as a function of the initial concentration ratio, showing the crucial effect of stoichiometry on the nucleation and crystal growth kinetics. Consequently, attention should be paid to the use of kinetic laws of barium sulphate precipitation to validate micromixing models. - Chemical Engineering Science, vol. 51, pp. 2449-2458.
Read More >>Influence de la pression de vapeur d'eau sur la cristallisation d'un sel de phosphate magnésien
- Journal de la Société Chimique de Tunisie, vol III n°2, pp. 105-112
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