Sharif Digital Repository

The aim of this study was to investigate the rate of increase in temperature of a phantom equivalent to body tissue by different groups of magnetic iron nanoparticles in the external magnetic field to kill cancer cells based on the hyperthermia method. To achieve this goal, three groups of dextran magnetic nanoparticles with different properties and reduced iron oxide-graphene oxide magnetic nanoparticles by M-rGO supercritical synthesis method were used. After XRD, FTIR, SEM, FESEM, VSM, TEM characterization tests, these materials were placed in a phantom made of agarose gel and with the same properties, in a magnetic field with fixed characteristics for all groups and during the process of... 

Iodine isotopes are among the most significant medical radioisotopes with a wide range of applications in therapy and diagnosis. The I-131 isotope is usually synthesized by irradiation of natural tellurium in atomic reactors. But there is an alternative route in which this isotopes is produced along with two other significant medical radioisotopes (i.e. Mo-99, Xe-131) by neutronic irradiation of uranium in the reactors. To separate iodine isotopes especially in the extraction process of fission fragments, it is necessary to be selective adsorption of iodine on a selective adsorbent. One of the most selective adsorbent for this application is copper. The aim of this study is to compare the... 

The main methods have been used clinically for cancer treatment are included: surgery, chemotherapy, radiation therapy and hyperthermia. Hyperthermia (heat therapy) treatment method in which by raising the temperature of the tumor it removed. Magnetic hyperthermia is known as a kind of hyperthermia that have been represent appropriate results. In this study, using iron oxide nanoparticle coated with graphene for cancer treatment under a magnetic field of the laser. In the first stage, graphene oxide nanosheets and nanoparticles Magntayt are synthesized by chemical oxidation and co-precipitation, respectively. At the end, the nanoparticles on the substrate of graphene layer is obtained... 

Bimetallic nanoparticles with unique structure, synergistic effect between two metals, and the tunable physical/chemical properties have been used for catalysis. Various methods exist for the staibility, and improvement of the catalytic performance of nanoparticles. In this thesis, different co-catalysts were applied to increase tha staibility, and activity of nanoparticles and metal oxides. In this way, Ni-based bimetallic nanoparticles including CuNi, CoNi, and AgNi, and AgPt with different concentrations were synthesized on the cerium oxide nanorods derived from cerium metal-organic frameworks and magnetic graphene oxide nanosheets, respectively and characterized. The catalytic... 

One the basic challenges during drilling of both vertical and horizontal wellbores is due to mud filtrate invasion into the formation. Addition of nanoparticles to composition of drilling fluid has been recognized as a measure of control and reduction of filtrate invasion. Despite notable advances in formulation of nano-enhanced drilling fluids, effects of surface wettability of nanoparticles on their performance have not been studied with any precision. Moreover, return permeability of a grain packed porous media after extreme invasion by mud filtrate has not been experimentally measured in a radial system, yet. The last but not least, Generation and development of mud cake opposite the... 

One of the most well-established methods of increasing oil production rate from existing fields is infill drilling. However, drilling these depleted reservoirs with conventional high density drilling fluids may cause formationdamage problems and subsequently reduce the expected production rate. To overcome these technical problems, the use of lightweight aphron based fluids isincreasing rapidly in the petroleum industry. Rheological and fluid loss performance of aphron based drilling fluids can be improved in the presence of nanoparticles; however, very limited information is available in this field. Moreover, a thorough knowledge about the hydrodynamic flow behavior of drilling fluids... 

Recent studies in nanotechnology field have shown this technology could solve many challenges and needs in oil and gas industry. As yet, many applications of nanoparticles in enhanced oil recovery have been reported. One of the most important applications is wettability alteration due to presence of nanoparticles in injecting fluid, which has recently been studied by several research groups. These studies indicate that, presence of nanoparticles in injecting water would improve oil recovery. However, there is no adequate information about the mechanisms affecting fluid flow in reservoir rock and its mathematical modeling.The aim of this project is to evaluate the effect of injection of... 

Today, due to limited number of light oil reservoirs, enhanced recovery from heavy oil reservoirs is taken into consideration. During the early production from heavy oil reservoirs, due to high viscosity, only a small amount (about 5%) of the oil can be produced; also after water injection operation due to unfavorable mobility ratio of water and oil, sorely more than about 10% of the original oil can be produced. On the other hand, fractured reservoirs represent about 20% of the world's oil reserves, while over 60% of the world's remaining oil reserves are in fractured reservoirs. Water flooding process leaves very high amounts of oil as remaining oil in these reservoirs too. One of the... 

Foam injection for enhanced oil recovery is concerned by petroleum engineers because it decreases adverse effects of fingering and gravity segregation caused by the injected fluid .Obviously foam stability is an important factor in the efficiency of this process. So investigating it is an imperative. One of the ways that less studied and can improve foam stability is using of nanoparticles. In this project effect of nanoparticles on foam stability and displacement mechanism during foam flooding has been discussed.
Study consisted of two sets of experiments. In the first part, the static foam stability in the presence of silica nanoparticles has been investigated. Also influence of... 

Using foam for reducing undesirable effects of fingering and gravity segregation in enhanced oil recovery through gas injection has attracted a rapidly increasing interest in recent years. Lack of stability of foam often limits its application. However there is a lack of systematic study of effects of unmodified and in-situ modified silica nano-particle on foam stability and foam behavior in the presence and absence of oil and also polymer effects from the prospective of analysis of foam dynamic stability, size of foam bubbles, and foam flow behavior in Hele – Shaw cell. Main objectives of this study are mechanistic investigation of effects of polymer – surfactant systems and in-situ... 

Ag / AgCl /TiO2 , 2 Ap / Ag / AgCl /TiO , 2 AgI /TiO and 2 Ap / AgI /TiO were prepared by the deposition-precipitation method on 2TiO (P25) nanoparticles and their photocatalyctic activities have been investigated under visible light and dark environments. Cationic surfactant plus 2 PVPI (topical solution and dry powder) as an iodine ion source and nonionic surfactant plus KI as an iodide ion source were used to prepar 2 AgI /TiO . In less than 30 minutes, 2 AgI /TiO which has been resulted from combination of cationic surfactant and 2 PVPI showed high efficiency on Escherichia coli under visible light when small quantities of it is used . However, AgCl sample prepared with cationic... 

In the first part of this work, citric acid monomer was selected to produce dendrimer through the divergent method using logical conditions (for controlling its functional groups) on the base of poly (ethylene glycol) as the core. Triblock copolymers (ABA-type) of citric acid and poly (ethylene glycol) (PCA-PEG-PCA) as biocompatible compounds were synthesized in four different molecular weights and applied as nanocarriers. The structure definition of the molecules and nanoparticles were carried out using different spectroscopy methods. Diameter of the synthesized copolymers was investigated using dynamic light scattering (DLS) experiments and transmission electron microscopy (TEM) and it was... 

In this research, an adsorptive affinity membrane has been prepared based on the combination of the nanofiber structure’s intrinsic characteristic in the dye adsorption and its membrane filtration properties. Electrospinning method has been used to prepare chitosan/poly(vinyl alcohol) (PVA) nanofibers. The morphology and properties of the prepared nanofibrous membranes were characterized using Fourier-transform infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (FE-SEM), image processing, atomic force microscopy (AFM), and thermogravimetric analysis (TGA). Also, the major drawback of electrospun nanofibrous membranes (ENMs) is their low mechanical resistance. So,... 

Acceleration of healing process for crucial wounds has been remained a challenging issue and it is critical to improve treatments against infection during wound healing period. Among various antimicrobial agents, silver components has been extensively since they are resistant against a wide range of bacteria. In this study, we developed electrospun mats composed of Polycaprolactone (PCL) and Polyvinyl alcohol (PVA) loaded with major silver components using co-electrospinnig method. Chitosan- Ag nanoparticles was synthesized using chitosan via heating prior to electrospinning. Various amounts of Silver components including Ag+, Silversulfadiazine (SSD) and Chitosan- Ag NPs were added to PVA... 

Immobilization of β-D-galactosidase represents an important approach for development of lactose hydrolysis technology.Chitosan proved to be an excellent carrier for β-Dgalactosidase immobilization, by both covalent binding and sol-gel entrapment combined with adsorption. Among different preparation methods of chitosan support particles for covalent binding, emulsion cross-linking was the most efficient, producing narrow-sized microspheres, without aggregation.The best process parameters of β-D-galactosidase immobilization by covalent coupling on chitosan microspheres were found as 3% glutaraldehyde cross-linker concentration, enzyme loading of 27 mg protein/g dry support, 6 h reaction time,... 

The effects of adding nanoparticles in partitioning of α-amylase in polymer/salt aqueous two phase system (ATPS) was studied in this research. First the binodal curves of magnesium sulfate salt with PEGs 2000,3000,4000,6000 and 10000 at 23 ° C has been plotted and the suitable system which was PEG 6000/ magnesium sulfate has been selected for studying the partitioning of enzyme. Thereupon the partition coefficient of α-amylase was measured and then effect of adding silica and graphene oxide nanoparticles was investigated. It was observed that nanoparticles caused a dramatic increase in partition coefficient and yield recovery (of top phase). For further investigation the partitioning of... 

In this study, a comprehensive 2D mathematical model has been developed for the simulation of physical and chemical absorption of carbon dioxide in hollow fiber membrane contactors in the presence of nanoparticles. The model were developed by considering molecular diffusion in radial and axial directions as well as non-wetting conditions. Carbon dioxide absorption was simulated from a gas mixture containing carbon dioxide and air, that flows in the shell. Also, absorbent containing nanoparticles flows in tube side and counter currently. Effects of presence of nanoparticles were modeled by taking into account two prominent mechanisms proposed in the literature for mass transfer enhancement in... 

One of the steps in the production of nuclear fuel pellets used in the core of a nuclear reactor is sintering. Sintering means the consolidation of a pressed powder sample into an integrated solid. This process can be done in different ways, such as traditional sintering, microwave, spark plasma, etc. In the process of fabrication of nuclear fuel pellets, after producing uranium dioxide in powder form and making corrections on the size distribution of powder grains, it would be nolded and then sintered. In this research, the temperature evolution of the green pellets introduced to microwave heating were investigated. In this report, a brief overview of the principles of microwave heating is... 

Optical metasurfaces are 2D structures of a repetitive arrangement of a number of nanoparticles that are artificially constructed and do not exist in nature. Important applications of optical metasurfaces are meta lenses, flexible solar cells and extremely small antennas. Fabricating surfaces with nanoparticles of proper geometry under light radiation along with elastic deformation, we can have optical metasurfaces with selective reflection or transparency in the visible spectrum. The aim of this project is modeling of an optical metasurface with elastic deformation leading to change of color and transparency. For this purpose, assuming vertical light radiation and linear polarization, we... 

In recent years, application of nanotechnology in medicine is growing rapidly, specially, in the area of drug delivery. One of most import applications of nanotechnology is the using of nanoparticles as a carrier in targeted drug delivery systems. Simulation of drug delivery and prediction of drug release are developing in experimental and industrial areas. Mathematical modeling is used in drug delivery systems because they are time and cost saving and also can be used to predict drug behavior. The aim of this research, is to provide a framework for designing nano drug carriers. To this end, uptake of nanoparticles into different types of cells with different characteristics, in different...