Sharif Digital Repository

In present study, it is tried to investigate the effect of physical properties on hydrodynamic and overall mass transfer coefficient of single drops using different experiments and then simulation of drop motion with OpenFOAM software version 1.7.1. the systems were choosen are toluene/acetone/water and n-butanol/succinic acid/water which their interfacial tensions are 36 and 1.6 mN/m respectively. Various type of nozzles have been used for produce of 1.5, 2, 3 and 4 millimeter drops. The results show that in absence of solute component, the rising velocity of toluene drops in each size is higher than rising velocity of butanol drops inside the water between 25 to 75 percent. But with... 

In this research, the effect of feed flow concentration on the separation of gas mixture of carbon dioxide and oxygen was investigated by using supported liquid membrane in the presence of nano particles. In order to achieve this purpose, supported liquid membranes were prepared by impregnating a porous hydrophilic PVDF support with TEG, cyclohexanol, TEG/Fe3O4 nano particles and cyclohexanol/ Fe3O4 nano particles. Permeability and selectivity of mixed gases CO2 and O2 were examined at five different CO2 concentrations in feed flow, constant feed flow rate and constant total pressure difference.
In all tests, the permeance of carbon dioxide through cyclohexanol and TEG membranes was... 

Mass transfer and axial dispersion coefficients for continues phase were calculated by axial mixing model for continues phase and forward mixing model for dispersed phase simultaneously. Experimental data was achieved in pulsed sieve plate column with 22 cm diameter. Toluene –water-acetone and Butanol-Succinic acid- water were used in this experiment. In these systems continues phase is water and mass transfer takes place from continues phase to dispersed phase. Experimental data involves drop size distributions and operating conditions andconcentration in both phases.For calculating overall mass transfer coefficient for drops the handlos and Baron Model was used. The axial dispersion... 

In this research, separation of carbon dioxide from a mixture of CO_2-N_2 with the aid of liquid membrane containing immobilized solution of diethanolamine-triethylene, known as facilitated liquid membrane, (DEA-TEG) in porous and hydrophilic poly vinylidene fluoride (PVDF) substrate was experimentally and theoretically carried out. The effects of DEA concentration, CO_2 partial pressure, and thickness of membrane on permeability coefficient, facilitation factor, permeation rate and selectivity of liquid membranewere investigated and importance of mass transfer resistance in gas phase on permeability or liquid membrane performance was also shown. Reversible reaction of complex formation... 

In this experimental work terminal velocity, velocity profile and aspect ratio of bubble with 1.49 mm diameter which ascend in pure water and infected by surfactant nonionic C10DMPO and surfactant ionic SDS in regime that surface tension is dominant, have been considered. Observations showed that with respect to entering nozzle, bubbles with this diameter have two initial stable shape; spherical and extended form on surface for horizontal needle and vertical nozzle. Results are (1) Bubbles with initial spherical shape had lower terminal velocity and higher aspect ratio with respect to bubbles with initial extended form, (2) Spherical bubble had aspect ratio about 1 at whole bubble column... 

In liquid-liquid extraction, as in gas absorption, two phases must be brought into good contact to permit transfer of material. The presence of nanoparticles in liquid phase can enhanced the rate of gas-liquid mass transfer. The benefits of nanofluids can be used to enhance the heat and mass transfer of liquid-liquid extraction. Standard test system with low interfacial tension that recommended by EFCE: n-butanol/water/succinic acid, was used in this project. The CNTs/n-butanol that was saturated of water used as dispersed phase. Water and succinic acid used as continuous phase and solute. Since there is no chemical reaction to take place between CNTs and n-butanol, In order to obtain well... 

Fractured carbonate reservoirs are mostly oil-wet to intermediate-wet. Due to the negative capillary pressure of the matrix poor spontaneous imbibition of reservoir brine occurs in such reservoirs, and water flooding leads into early break through due to the high conductivity of the fracture network. Some surfactants have the ability to change the wettability of rock matrix toward water-wet state by adsorbing onto the rock surface. The phenomenon can result in spontaneous imbibition improvement and thereby increasing water flooding efficiency and recovery from fractured carbonate reservoirs. In this thesis the effect of some surfactants on the wettability of Iranian carbonate reservoir rocks... 

Nanofluids are new engineering materials with great potential for application in process industries. Their enhanced heat-transfer properties are reported in recent literatures. However, with respect to the influence of nanoparticles on mass transfer characteristics, limited number of studies available in the literature, deal primarily with gas-liquid systems. In this work, mass transfer performance and droplet behavior along a pulsed liquid-liquid extraction column, is studied where SiO2 nanoparticles with concentrations of 0.01, 0.05 and 0.1 vol% and different hydrophobicities are applied to the dispersed phase. Using ultrasonication, nanoparticles were dispersed in kerosene as the base... 

In this study the effect of nanoparticles on the mass transfer of dispersed phase in the liquid-liquid extraction systems, containing toluene with acetic acid as dispersed phase and saturated water of toluene as continues phase was investigated. For the ease of dispersion of nanoparticles in nonpolar organic dispersed phase, with the use of a novel method, hydrophobic tiania nanoparticles were synthesized and during producing with the sole-gel method were modified by adding Tetraethyl Ortho titanate as modifying agent, also the smallest hydrophobic nanoparticles of magnetite were synthesized by co-precipitating method and then, under optimum thermal condition were coated by adding Oleic... 

The aim of the current project is preparation, characterization and microfiltration evaluation of nanofiberous membrane. In order to prepare membranes, the electrospinning method was utilized and polyacrylonitrile and N-N, dimethylformamide (DMF) were used as the polymer and the solvent, respectively. As the nanofiber diameter controls the structure of the membrane and also bead formation reduces the membrane uniformity, at first the effects of four most influential electrospinning parameters, such as solution concentration, applied voltage, floe rate, and the distance between needle tip and the collector, on average fiber diameter and bead area density were investigated via response surface... 

In this research, modification of polysolfune ultrafiltration membranes is investigated. The enhancement is done via grafting of the acrylic acid as a hydrophilic monomer on the membrane surface. This is a free radical grafting method in which free radicals are formed via redox reaction of ammonium persulfate and sodium metabisulfite as an initiator. Water contact angle, molecular weight cut-off, pure water flux and fouling experiments were used to figure out the optimum conditions for the membrane performance. In addition, scanning electron microscopy (SEM) and atomic force microscopy (AFM) were utilized to determine morphological changes of the membrane surface. Furthermore, Fourier... 

Phenolic compounds are important environmental pollutants that the removal and separation of them from the water and industrial wastewater especially in the oil industry is essential before entering the environment. In the present study, the removal efficiency of the adsorbent silica aerogel 4-Chlorophenol and 4-Bromophenol as phenolic compounds from aqueous solution was surveyed. In this research, the effects of various factors such as contact time, pH, and initial concentration of the pollutant and the adsorbent on the adsorption were studied. It was observed that there is a large amount of adsorption in acidic pH and this amount increases by incrementing the concentration of the... 

Regarding to the effect of nanoparticles on mass transfer and hydrodynamics characteristics, limited number of studiesavailableinthe literature.In this work, mass transfer performanceand hydrodynamic characteristics nanofluidshavebeeninvestigated in the liquid−liquid extraction process. The chemical system of toluene-acetic acid-water was used, and two Extraction columnswith diameter of 10cm and height of 55cm and 6 cm were designed. The drops were organic nanofluids containing silica nano-particles and carbon nano-tubes.Synthesized silica nanoparticles by sol-gel methods, were modified with Triethoxyoctylsilane and Polydimethylsiloxane as well as Carbon nano-tubes were modified with dodecyl... 

composite membranes with PVC as the matrix, Alumina nanoparticles as filler and PVP as additives, were optimized and built. First, the interaction of PVC, PVP and alumina particles on the membrane structure and its performance was investigated by using Design expert software. The membranes which the software proposed were prepared and pure water permeability and flux decline tests were done according to evaluate the membranes performance in membrane bioreactor (MBR). And the results were imported in software and material effects on the performance of each membrane were analyzed. In order to better assess the efficiency and effectiveness of alumina nanoparticles on membrane, different values... 

In this study the main goal is preparing an appropriate UltraFiltration membrane from PolyVinyl Chloride for using as substrate in producing efficient Reverse Osmosis membranes to use in sea water desalination. each membrane should have some specifications to use it as reverse osmosis membrane’s substrate. One of the most important specifications is the appropriate pore sizes. To investigate this subject pure water flux and PolyEthylene glycol rejection of prepared membranes is tested. After investigation of this parameters and proving them, RO membranes are prepared using this membranes.
Salt rejection of Brackish water (2000ppm) and sea water (Persian gulf,32000ppm) are measured in... 

Fischer-Tropsch synthesis is a major part of gas-to-liquid (GTL) technology, which converts natural gas into liquid fuels with very low sulfur and aromatic content. Nowadays, this exothermic reaction is performed in slurry reactors; therefore it is essential to separate solid catalyst particles, suspended in the liquid products. In this study, without performing real experiment and chemical reaction, separation of Alumina supported Cobalt Catalyst from wax is carried out by internal filtration. For the first time in this research, the effect of different parameters like pressure difference, wax viscosity and filter pore size on the quantity and quality of filter performance is investigated.... 

Surface phenomena and dynamic Interfacial properties play an important role in gas- liquid and liquid-liquid multiphase process from various industrial applications to understand fundamental phenomena. However, there is no experimental equipment and efficient methods for quantitative and detail investigation of interfacial properties under fast and non-equilibrium dynamic condition due to mobility and refreshing of interface (such as rising bubble). Also existing models accompanied with a lot of simplifications which is not yet validated with a proper experimental data. In presented thesis work for the first time, quantitative study of dynamic adsorption layer in multiphase systems and more... 

One of the chief kinds of receptors in cancer angiogenesis is the tyrosine kinase VEGFR-2. This target receptor is presented in both forms; active and inactive. adenosine triphosphate (ATP) residue is the location of deformational change from inactive to active form. Small molecule inhibitors have been designed for various forms of this receptor. In current study, the interaction of small molecular inhibitors including; Regorafenib, Cabozantinib and Thiosanib with dual VEGFR-2 receptor forms was investigated by molecular dynamics with Gromacs software. Cabozantinib and Regorafenib inhibitors had a lower binding energy in interaction with the inactive state however, Thiosanib inhibitors in...