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Control of Eutrophication in Anzali Wetland by Artificial Floating Islands
,
M.Sc. Thesis
Sharif University of Technology
;
Abrishamchi, Ahmad
(Supervisor)
Abstract
Anzali wetland, in the Caspian Sea, northern Iranian province of Gilan, ranges from fresh near the tributary streams to brackish near the mouth into the harbor and the sea. Anzali wetland has faced with the serious levels of eutrophication because on the other hand, the lagoon has decreased in size during current century, to less than a quarter of its former extent and on the other hand, this wetland is faced with entering a huge amount of nutrient elements due to human activities in its watershed. Discharge of industrial wastewater, animal wastes, timber harvesting and the most important entering, rice farms irrigated wastewater are of the considerable causes of eutrophication in wetland....
کلیدواژه های تکراریCurcumin loading potentiates the neuroprotective efficacy of Fe3O4 magnetic nanoparticles in cerebellum cells of schizophrenic rats
, Article Biomedicine and Pharmacotherapy ; Volume 108 , 2018 , Pages 1244-1252 ; 07533322 (ISSN) ; Ashrafi Hafez, A ; Abdorahim, M ; Abdollahifar, M. A ; Shabani, R ; Peirovi, H ; Simchi, A ; Ashtari, K ; Sharif University of Technology
Abstract
Background: The aim of this study was to investigate the neurotoxic effects of Fe3O4 magnetic- CurNPs on isolated schizophrenia mitochondria of rats as an in vivo model. Methods: We designed CMN loaded superparamagnetic iron oxide nanoparticles (SPIONs) (Fe3O4 magnetic- CurNPs) to achieve an enhanced therapeutic effect. The physicochemical properties of Fe3O4 magnetic- CurNPs were characterized using X-ray diffraction (XRD), and dynamic laser light scattering (DLS) and zeta potential. Further, to prove Fe3O4 magnetic- CurNPs results in superior therapeutic effects, and also, the mitochondrial membrane potential collapse, mitochondrial complex II activity, reactive oxygen species generation,...
Electrochemical Properties and Stability of Ruddlesden-Popper (RP) Nickelates as Cathodes for IT-SOFC
, Ph.D. Dissertation Sharif University of Technology ; Faghihi Sani, Mohammad Ali (Supervisor) ; Madaah Hosseini, Hamid Reza (Co-Supervisor)
Abstract
For improving cost competitiveness of both SOEC and SOFC technology, it is desirable to reduce the temperature of operation preferably down towards 500 oC – 600 oC, as this will slow down the rate of various degradation processes and allow use of much cheaper materials for auxiliary components. In this range, the oxygen electrode typically dominates the cell resistance, and hence there is a need to develop cost effective electrodes with improved performance at low temperature. Whereas the oxygen exchange on Ruddlesden-Popper type Ni based compounds like Pr2NiO4 with interstitial oxygen defects is known to be very fast, reported electrode performance of micron-sized composites based on these...
Performance Comparison of Membrane Bioreactor and Activated Sludge Processes in Starch Wastewater Treatment
, M.Sc. Thesis Sharif University of Technology ; Shayegan, Jalaledin (Supervisor)
Abstract
In this study the performance of the conventional activated sludge and the membrane bioreactor systems were investigated and their operations were compared. . A membrane bioreactor and a conventional activated sludge system which includes one aeration basin and one settling tank were designed and constructed. The feed was synthetic and the BOD:N:P ratio was 100:5:1. In order to starting the systems, the sludge supplied from the municipal wastewater treatment plant and inoculated. Then, the inoculated sludge was adapted to treat the starch wastewater with step by step increasing the feed COD. . The performance of two systems investigated in inlet COD=2500 mg/L and four hydraulic retention...
Kinetic and Mechanistic Study of Oxidation of Dopamine by Manganese (IV) Clusters with Relevance to Photosystem II
, M.Sc. Thesis Sharif University of Technology ; Mohammadi Boghaei, Davar (Supervisor)
Abstract
Studying of synthetic models which have many similarities to Oxygen Evolving Complex (OEC) in Photosystem II (PS II) can play a very significant role in gaining an insight to mechanism of oxidation of water in PS II. The aim of this study is to investigate the mechanistic and kinetic aspects of oxidation of dopamine as an important neurotransmitter in body by tri and tetranuclear oxo-bridge manganese clusters which have been reported in the past to get some information about the influence of protonation and deprotonation of oxo-bridges and water molecules bonded to these clusters on properties of them in redox reactions.In aqueous media, the trinuclear complex...
Numerical Study of Combustion of H2-O2 Cryogenic Propellant under Supercritical Condition
, M.Sc. Thesis Sharif University of Technology ; Mardani, Amir (Supervisor)
Abstract
In order to improve performance and optimize design of high pressure combustion devices such as liquid rocket engine, gas turbine engine, and diesel engine there is a need for comprehensive understanding of injection, mixing and combustion in supercritical condition. Under this condition chamber pressure is higher than critical pressure of fuel and oxidizer. The characteristic of supercritical condition, include changing thermophysical properties such as density, CP, and compressibility factor. Therefore under this condition ideal state equation cannot correctly predict the mentioned properties. These characteristics make supercritical combustion different from other combustion regimes....
Numerical Investigation of Kerosene Spray Combustion with Preheated and Diluted Airflow
, M.Sc. Thesis Sharif University of Technology ; Mardani, Amir (Supervisor)
Abstract
MILD combustion can be a promising technology to prevent global warming. In this study, for the first time, the numerical simulation of MILD spray combustion of kerosene fuel with preheated and diluted air has been conducted in the faculty's SMSTR test stand. The modeling framework is based on the Reynolds averaged Navier-Stokes turbulence approach and the standard k–ε model, the DPM discrete phase model, and the EDC combustion model, using the skeletal chemical mechanism of Jet A POSF10325 kerosene with the air and droplet being tracked in Lagrangian coordinates. The simulation is done in a steady state and by an axisymmetric method, and the effects of inlet oxygen concentration, inlet air...
Kinetic Study of Heterogeneous and Homogeneous Catalytic Reactions in Molecular Solvents and Ionic Liquids
, Ph.D. Dissertation Sharif University of Technology ; Gholami, Mohammad Reza (Supervisor)
Abstract
Selective oxidation of cyclohexene and styrene were investigated using molecular oxygen under mild conditions. Au/TiO2 and Au/Al2O3 surfaces were impregnated with three different Ionic Liquids. Supported Ionic Liquids gold nanocatalysts are particularly versatile catalysts for oxidation reaction with exceptionally high efficiency and significant selectivity.
Selective oxidation of alkenes by hexadecyl-trimethyl-ammonium bromide-stabilized gold nanorods and gold nanosphere were investigated using molecular oxygen in aqueous solution under mild conditions. Colloidal gold nanoparticles are particularly versatile catalysts for oxidation reaction with exceptionally high efficiency and...
Selective oxidation of alkenes by hexadecyl-trimethyl-ammonium bromide-stabilized gold nanorods and gold nanosphere were investigated using molecular oxygen in aqueous solution under mild conditions. Colloidal gold nanoparticles are particularly versatile catalysts for oxidation reaction with exceptionally high efficiency and...
Study of Electronic Structure of 3d Transition Matals-Doped TiO2 Based on Band Calculations:a DFT Study
, M.Sc. Thesis Sharif University of Technology ; Gholami, Mohammad Reza (Supervisor) ; Elahifard, Mohammad Reza (Co-Advisor)
Abstract
We present a systematic study of the composition, electronic structure, and the band gap energy in pure, Cu-doped and O-vacancy@Cu-doped TiO2 using periodic density functional theory (DFT) calculations by several techniques implemented by Abinit code. Herein, the effect of Cu impurity and O-vacancy in three famous crystalline structures of TiO2 i.e. rutile, anatase and brookite, with 6.25% and 12.5% of Cu impurity were investigated. Bulk titania was modeled using 2×2×1, 2×1×1 and 1×1×1 super cells (24 atoms with formula of Ti8O16) and 2×2×2, 2 2×1 and 1×2×1 super cells (48 atoms with formula of Ti16O32) for rutile, anatase and brookite phases, respectively. One Ti atom replaces with Cu atom...
Comprehensive Study of an Ag@Pt Core–shell Nanoparticles Supported on Carbon Structure in a Proton Exchange Membrane Fuel Cell
, Ph.D. Dissertation Sharif University of Technology ; Kazemeini, Mohammad (Supervisor) ; Bastani, Dariush (Supervisor)
Abstract
Core-shell structures of Ag@Pt nanoparticles (NPs) dispersed on Carbon Vulcan XC-72, Multiwalled carbon nanotube and reduced graphene oxide (rGO) support containing different Ag:Pt mass ratios and applied to the oxygen reduction reaction (ORR) in a proton exchange membrane fuel cell (PEMFC) were synthesized by the ultrasonic and reduction treatment method. The morphology of as-prepared catalysts characterized by the high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and induced coupled plasma atomic emission spectroscopy (ICP-OES). The ORR activities and stabilities of catalysts were studied through electrochemical measurements utilizing the Cyclic Voltammetry...
Experimental Study of Oxygen Reduction Reaction (ORR) on Cu-alloys, Electrocatalysts in Alkaline Solution and Theoretical Investigation of Oxygen Adsorption on Cu-alloys Nano-clusters
, Ph.D. Dissertation Sharif University of Technology ; Gobal, Fereydoon (Supervisor)
Abstract
In this study, electrochemical oxygen reduction reaction (ORR) was studied on Cu, Pd, Rh, Pd-Cu and Rh-Cu alloys in alkaline solution. Pd-Cu and Rh-Cu alloys were prepared by electrochemical methods. On copper electrode it is found that direct oxygen reduction is accompanied by the electrochemical reductions of copper oxides. Also, mechanism and kinetics of reaction change as the amount of copper oxides increase on the surface. For electrodeposited alloys, it is indicated that the reactivity of Pd-Cu and Rh-Cu alloys toward oxygen reduction is higher than pure Pd and pure Rh. The maximum reactivity among Pd-Cu alloys is related to the sample with 24.5% copper content while the maximum...
Experimental Study of Oily Wastewater Treatment by Hybrid Baffled Bioreactor
, M.Sc. Thesis Sharif University of Technology ; Alemzadeh, Iran (Supervisor) ; Vosoughi, Manochehr (Supervisor)
Abstract
Oil refineries, petrochemical factories and oil platforms produce a large amount of oily wastewater every day. If these wastewaters are released in environment, it can damage soil and water seriously. Although, Biological treatment of oily wastewaters is a well-established method for remediation of these wastes, efficiency of conventional systems such as Activated Sludge, aren’t very high. Also these systems have many problems such as instability during hydraulics shocks and bulking phenomena. the hybrid bioreactor system are designed to increase the efficiency of treatment by allowing greater organic loads, increasing microbial concentration by using attached and suspended bacteria, and...
Management Treatment of MDF Effluent by Soil Aquifer Treatment (SAT)
, M.Sc. Thesis Sharif University of Technology ; Oskoee, Mohammad Mahdi (Supervisor) ; Jamali, Sirous (Co-Advisor)
Abstract
This study deals with the treatment of medium density fiberboard (MDF) effluent aiming at the removal of TSS, COD, BOD and Turbidity by means of soil aquifer treatment (SAT). Removal of parameters were evaluated during transport of MDF effluent under unsaturated flow conditions in 1-m soil (sandy-clay soil) depth. The experimental results showed that the new process with SAT to be very effective. The TSS, COD, BOD and turbidity removal average was about 99%, 30%, 89 and 98.5% at the optimum operation condition, respectively. The SAT should be added before the UASB in order to achieve high removal rate of COD and BOD. The UASB (concentration sludge 40000 mg/l) after SAT treatment MDF...
Structural and Functional Models for the Molybdenum, Tungsten and Copper Enzymes: Synthesis, Properties and Reactivity
, Ph.D. Dissertation Sharif University of Technology ; Mohammadi Boghaei, Davar (Supervisor)
Abstract
In order to obtain more insight into the enzymatic oxygen-atom-transfer (OAT) process and elucidate the relation between the structure and function of the synthetic model complexes, new molybdenum and tungsten complexes containing different chelating ligands were systematically prepared and investigated. Herein, the cis-dioxo-molybdenum(VI) complexes with new aromatic dithiolene ligands, formulated as [MoO2(2,3ppdt)2]NR4 and [MoO2(3,4ppdt)2]NR4, (2,3ppdt= pyrido-2,3-pyrazine-2,3-dithiolato, 3,4ppdt= pyrido-3,4-pyrazine-2,3-dithiol and R= Et or Bu) were prepared and investigated by elemental analysis, IR, 1H NMR and UV-Vis spectroscopic methods. An OAT reaction of [MoO2(2,3ppdt)2]2– with PPh3...
Modeling of Biological Matter Cycling in Shallow Lake by System Dynamic Method
, M.Sc. Thesis Sharif University of Technology ; Abrishamchi, Ahmad (Supervisor)
Abstract
Modeling of water quality in shallow lake is the goal of this roject.Matters cycling in environment will be explained. The dissolved Oxygen will be assigned the most important factor in water quality. The phytoplankton Growth rate and fatality rate will be modeled By LOTKAVOLTERRA equations. The nitrification by nitrifying bacteria and Michael Menton equations will be explained. Modeling will be executed By System Dynamic which feedbacks are the most com ponents of it.The model will be built with equations and coefficients in literatures and this model run by VENSIM®software. We will assure by some extreme condition tests about the structure of the model and finally we will make a...
Deling and Simulation of Human Lung
, Ph.D. Dissertation Sharif University of Technology ; Bozorgmehry Boozarjomhery, Ramin (Supervisor)
Abstract
The bronchial tree consists of two main parts: conducting airways and respiratory airways. Parametric Lindenmayer System (L-System) has been used for modeling of the structure. The conducting airways are divided into two parts: central region consisting of trachea up to segmental bronchi and bronchioles located in the bronchopulmonary segments. The boundary of these segments has been found by image processing techniques. Stochastic Parametric L-system has been used for modeling of acinar region. To find the characteristic properties of conducting airways and respiratory bronchioles, an intelligent method has been developed. The parameters of the model are either age dependent or...
Mathematical Modeling and Simulation of Hyperbaric Oxygen Therapy in Tumor Growth Process
, M.Sc. Thesis Sharif University of Technology ; Abdekhodaei, Mohammad Jafar (Supervisor) ; Saadatmand, Maryam (Co-Supervisor)
Abstract
Today cancer is one of the leading causes of death worldwide. It is caused by some cells that they gather together in part of the body and they have an abnormal and very high proliferation rate. Investigations on tumors have shown that when tumor volume increases, oxygen concentration in some regions of tumors decreases and this hypoxic condition leads to some cancer hallmarks, e.g. angiogenesis, deregulation of apoptosis, and shift in cell energy sources. So treatment strategies that can increase tissue oxygenation are good choices for cancers. Hyperbaric oxygen therapy (HBOT) which is used to treat diabetic ulcers and carbon monoxide poisoning, have been used experimentally for cancer and...
Kinetic Modeling of Propane Dehydrogenation on Industrial Pt-Sn/γ-Al2O3 in Presence of Oxygenated Compounds
, M.Sc. Thesis Sharif University of Technology ; Khorasheh, Farhad (Supervisor)
Abstract
The study on the propane dehydrogenation process has been receiving significant attention due to the growing demand for propylene. The aim of this research is to develop an appropriate kinetic mechanism for dehydrogenation of propane over an industrial Pt–Sn/γ-Al2O3 catalyst in the presence of a very small amount of water. The reaction is carried out over the temperature range of 575 – 620 º C at atmospheric pressure. The results showed that a small amount of water and methanol can improve the performance of catalyst and also, increase the selectivity to COx. Addition the 0.5, 0.45, 0.3 water and 0.1, 0.05, 0.02 methanol are the optimum amount of these oxygenated compounds in order at...
Oxygen Enrichment of Air by Membrane Technology to Reduce Energy Consumption
, M.Sc. Thesis Sharif University of Technology ; Bastani, Dariush (Supervisor)
Abstract
In various industries, for energy production, fossil fuels are burned. Oxygen needed for combustion, taken directly from the ambient air; So that the inert gas is about 80%. The presence of this inert gas, mainly nitrogen, reduce combustion efficiency and increase the use of combustible material. In this project with the help of membrane technology, was used to remove the amount of nitrogen in the air so that the incoming air into the combustion chamber is enriched with oxygen. For this purpose, several gas separation membrane was applied and evaluated. Then, according to the oxygen enrichment, fuel efficiency and the amount of savings, increasing chamber temperature, reduction manufacturing...
Impermeability of Oxygen in Passive/Active Polyethylene Nanocomposite Films
, Ph.D. Dissertation Sharif University of Technology ; Bagheri, Reza (Supervisor) ; Shojaei, Akbar (Supervisor)
Abstract
In this study, polyethylene films made of LDPE / LLPE / reinforced with mechanical barrier of clay and reactant of iron nanoparticles were made in their optimal combination and necessary improvements were made on them. Investigations show that, independent of volume fraction, the addition of spherical nanoparticles does not have much effect on reducing the polymer matrix’s permeability. In nanocomposites containing cylindrical particles, for considerable reduction of the permeability, over 20 volume percent of nanoparticles it is required, while in platelet nanoparticles, less than 10% vol is sufficient. In clays with modifier concentration above the cation exchange capacity, there is less...