Sharif Digital Repository

In the recent years, nanophotocatalytic process for E. coli inactivation has become considerable choice for water treatment. Having suitable catalytic characterizations, nanophotocatalysis could be considered as an alternative to current E. coli disinfections methods.
In this study, antibacterial effect of Fe-Cd/TiO2 (TiO2 doped with Fe and Cd) under visible light was reported for the first time. The Results show that by comparing Fe-Cd/TiO2 with commercial TiO2 (P25 Degussa), bactericidal efficiency of this codoped photocatalysis under visible light is high and effective. Indeed, Nanoparticle of Fe-Cd/TiO2 disinfects E. coli (cell density: 107 CFU/ml) almost completely within 55 min... 

Paclitaxel is used as a drug against breast and ovarian cancers. Although paclitaxel has high biologic activity, it has very pour solubility in water like some other drugs. Since drugs should be solved in water to be absorbed by the body, for absorb enhancement, we should use carriers which includes both polar and non polar sites. eta-Cyclodextrin which has this feature is capable for producing inclusion complex in its hydrophobic pores with non polar materials. In this project by adding polymeric polyacrylamide branches on beta-Cyclodextrin, polymeric nano structure has been developed to enhance water solubility in comparison with pure beta-Cyclodextrin. Study on producing polymeric nano... 

MOFs are new class of materials that are used in different scientific fields because of their hybrid structure. In this project, focused on two specific applications, and aim is synthesis of a nanostructure which has antibacterial and photocatalytic activity. ZIF-8 because of its chemical and physical stability has been studied. For improving antibacterial influence and photocatalytic activity, silver nanoparticles are added to the structure. Magnetic nanoparticles covered by silica were used as core to facilitate separation process, ZIF-8 structure was constructed as shell on SiO2@Fe2O3 nano spheres. Magnetic nanoparticles improving stability of ZIF-8 in aqueous solutions. Synthetic nano... 

The partition coefficients of L-Lysine HCL were measured in polymer-salt aqueous two-phase systems. These systems contain polyethylene glycol with nominal molecular weight of 4000 or 10000 and two different salts (di-potassium hydrogen phosphate or tri-sodium citrate 5,5-hydrate). The experimental data were obtained at temperatures 293.15, 298.15 and 303.15 K. The effects of temperature, pH, polymer and salt concentrations, polymer molecular weight and salt type on the partitioning of L-Lysine HCL were also studied. The results showed that salt concentration has a significant effect on the partition coefficient while temperature has a low effect. The experimental partition coefficients of... 

In this research, the partitioning of Penicillin G-Acylase in aqueous two-phase systems (ATPS) containing poly ethylene glycol (PEG) 20000 or 35000 and potassium di-hydrogen phosphate (KH2PO4) or sodium citrate (C6H5Na3O7.5H2O) is measured at three temperature (301.2, 307.2 and 310.2) K. The effects of temperature, polymer molecular weight, polymer and salt concentrations on partitioning of Penicillin G in the aqueous two-phase systems are studied. The experimental data showed that composition of salt has a large effect on partitioning of Penicillin G in ATPS and temperature of system has small effect on the partitioning. The modified local composition model was used to obtain the activity... 

This project surveys bioregeneration of granular activated carbons contaminated with phenolic compounds. To carry out this survey, the procedure of phenol absorption on the surface of activated carbon was studied and their adsorption isotherms were calculated. In the first step, newly activated carbon was contaminated with phenol solution and optimum amount of carbon in phenol elimination was 0.5g. Then, the effect of time contact on phenol elimination was studied and eventually 1 hour of time contact was determined as the equilibrium time of phenol adsorption. In the second step, kinetics of adsorption of phenol and different stages of adsorption were studied. The results of this study... 

In this project an enzymatic peroxidase biosensor based on two naono structured material 1-Polyaniline nananofibers 2-Polyethylene glycol-Poly citric acid copolymer was studied for phenol detection.Polyaniline nanofibers and poly ethylene glycol-poly citric acid copolymer were synthetized by chemical polymerization.Electrochemical behaviors of these biosensors were studied using cyclic voltammetry (CV) and amperometric techniques. The amperometric response of the coated electrodes is highly stable with 92% of the initial activity remaining after 5 determinations. These phenol biosensors show an oxidation peak at 0.55V. The amperometric response for phenol biosensor based on Polyaniline... 

In this research, Response Surface Methodology was applied to study the effects of Na-Montmorillonite and glycerol on some functional properties of corn starch films. Films were prepared by casting method according to central composite design. No antimicrobial activities were observed against Escherichia coli and Staphylococcus aureus. The minimum of hydrophilicity and the maximum of tensile strength were obtained by maximization of clay and minimization of plasticizer in the considered range, which resulted in minimum transparency. Biodegradation of corn starch/glycerol/Na-MMT nanocomposites by soil burial according to ASTM D6400 and enzymatic degradation tests were carried out for up to 6... 

In First part, the electrophoretic deposition method was utilized to immobilize TiO2 particles on stainless steel substrates. In addition, for the first time, statistics-based experimental design using response surface methodology (RSM) was employed to investigate the effect of four key coating parameters (i.e. applied voltage, calcination temperature, photocatalyst weight percentage, and deposition time) on the photocatalytic degradation. Analysis of variance revealed that the proposed model was adequate. X-ray diffraction (XRD) and scanning electron microscope (SEM) were used to evaluate the effects of the parameters on degradation efficiency. The optimum applied voltage, calcination... 

Sustainable development requires the development and promotion of environmental management and a constant search for green technologies to treat a wide range of aquatic and terrestrial habitats contaminated by increasing anthropogenic activities. In this work we investigated the ability of four previously isolated fungi, BBRC 9057, BBRC 20020, BBRC 9058 and BBRC 9002, in degradation of polycyclic (PAHs) and the effect of UV irritation on fungi cell growth and degradation of PAHs. Also we studied the degradation of anthracene by thermophilic filamentous fungi in liquid and soil slurry bioreactor. Cell growth and anthracene degradation ability of BBRC 9057 increased 6.51 and 1.82 times rather... 

β-galactosidase enzyme is immobilized from Kluyveromyces lactis by Microencapsulation method in various compositions of sodium alginate and Carboxymethyl cellulose. Optimum stabilization was gained at 1.85% sodium alginate, 0.9% carboxymethyl cellulose and 2% calcium chloride through applying Surface response methodology. Yield of immobilization and activity was 54.94% and 65.27%. variation of yield of immobilization versus alginate concentration was a quadratic curve with the maximum. When alginate's concentrations is low, the cavities diameter is great, so the enzyme leaks from capsule while immobilizing. At high concentrations of alginate, despite the smaller cavities, immobilization... 

In this research, experimental study and modeling of biodiesel production process from microalgae has been investigated. First, to have a biomass with suitable lipid content, a novel two-step process based on cultivation under nutrient sufficient followed by cultivation under nitrogen starvation condition has been proposed. Then the effect of using different organic and inorganic carbon sources on this process has been investigated which the results indicated that sodium acetate had a better performance compare to other carbon sources. In the following, the effect of using different light regimes on growth rate, lipid content and fatty acid composition have been investigated. Experimental... 

Combined composites consisting of nanofibers and hydrogels were fabricated to grow cells in an environment that mimicked the extracellular matrix. Electrospan nanofibers were spun and hydrolyzed under optimized conditions consisting of polycaprolactone (PCL) and gelatin and then incorporated into alginate and gelatin hydrogels. Nanofibril-containing (NF / hydrogel) hydrogel hybrids were ligated by calcium chloride in the presence of encapsulated beta cells. The mechanical properties of NF / hydrogel scaffolds were significantly increased in proportion to the NF content in NF / hydrogels. Beta cells killed in NF / hydrogels showed higher adhesion to the matrix compared to samples without NF.... 

The main strategy for treating solid cancers is based on the very early diagnosis of a malignant tumor, and in general the smaller the tumor, the greater the likelihood of successful treatment. Magnetic Resonance Imaging (MRI), based on the nuclear magnetic resonance phenomenon, provides the possibility of detecting early malignant tumors with the assistance of appropriate contrast agents. Hence, researchers continue to develop novel magnetic materials to achieve this aim. Superparamagnetic nanoparticles have become the focus of these studies because their superparamagnetic, biocompatible and hydrophilic properties would be revealed after modifying the particle surface by suitable... 

Some widely used drugs such as paclitaxel (PTX) are poorly water soluble. The clinical use of PTX with solubilizer causes side effects. These problems limited its application in treatments. In this work has been studied the effect of β-CD-g-PG (HPCD) hybrid nanomaterials, conjugated PG branches onto β-CD core, on the water solubility of PTX. First HPCD has been synthesized. Then the inclusion complex of PTX with HPCD was prepared. The inclusion complex efficiency for PTX:HPCD complex in 1:25 mole ratio was 87%. Then solubility of PTX with HPCD in water has been determined, showing Ap type phase solubility diagram. Then stability constants were calculated. The first order and second order... 

The main objective of this project is the deposition of photo-catalysts on cement and concrete blocks with an emphasis on commercialization. We started with an extensive study of common methods introduced in previous literature, and conclude with a number of suggestions for industrialization. First, slurry and sol-gel deposition of the photo-catalysts on blocks of type 2 commercial cement which is one of the most used materials in construction of buildings and waste-water treatment plants has been examined to reach a method of sample formation. Due to the simplicity of common methods and low quality of formed samples (less than 5 percent aging efficiency), the obtained experience was used to... 

Design, simulation, optimization and manufacturing of an enzyme-based microfluidic biosensor has been carried out during this research to measure histamine concentration in a sample. The designed biosensor is composed of a micro-bioreactor to degrade histamine and yield hydrogen peroxide, and a chemical reactor to measure the amount of hydrogen peroxide, using chemiluminescence methods. The geometry of the bioreactor and chemical reactor is developed through comparison and optimization of several different geometries. In theory, the designed sensor can determine histamine concentration in a range of 10M to 1mM under one minute, with a maximum error of 5%. Designed biosensor is built using... 

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... 

Due to the high cost and destructive effects of fossil fuels, the biogas production as a renewable and environmentally friendly fuel attracted much attention. In this regard, several targets are considered in this research. First, in order to increase of biogas production yield and accelerating the rate limiting steps in anaerobic digestion of wheat straw (lignocellulosic feedstock), the effect of additives containing trace elements (Fe and Ni) in form of nanoparticles and their salts was investigated through batch experiments. The results showed that addition of nanoparticles or salts resulted in the increase of methane production rate during the first 4 days of experiments. Then, a... 

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,...