Sharif Digital Repository

Artificial immune systems (AIS) constitute a novel area of bio-inspired computing. Biological models of the natural immune system, in particular the theories of clonal selection, immune networks and negative selection, have provided the inspiration for AIS algorithms. Moreover, such algorithms have been successfully employed in a wide variety of different areas, but have not been applied for chemical processes yet. One important part of the immune systems is lymphatic system. Clonal selection is one of the few algorithms that belong to the family of AIS techniques. Clonal selection algorithm is the computational implementation of the clonal selection principle. In this project, we have... 

The chemical vapor deposition (CVD) of graphene from methane on a copper substrate is the most promising method for production of large-area graphene films. There have been long-standing challenges in this field such as controlling the graphene coverage, film quality, the number of layers, and the nucleation density of graphene domain. These challenges can be overcome by developing a fundamental understanding of the graphene growth process. The main aim of this study is to control nucleation density of graphene domains. Chemical vapor deposition (CVD) graphene is polycrystalline, and grain boundaries in graphene film have been identified to degrade the properties of graphene as a membrane... 

The increasing utilization of silver nanoparticles (Ag-NPs) in industrial and consumer products has raised concern to wastewater treatment utilities, due to its antimicrobial activity. In this research, recovery of silver nanoparticles from wastewater via using activated carbon and convert it into usable nanoparticles is presented. real waste of silver nanoparticles have been used and activated carbon as adsorbent has a high absorption recovery for silver. Under the optimized experimental parameters e.g. pH, temperature, time of process, and amount of activated carbon, an absorption maximum was achieved and over than 99% of silver nanoparticles can be removed from wastewater. After the... 

The optimum wave functions and calculation method were obtained using a 24 factorial design. Based on preliminary experiences, the following four factors at two level was selected: electron correlation, triple-ξ valence shell, diffuse function and polarization function.
The wave functions for calculating gas phase 1H chemical shifts of primary and secondary alcohols were optimized using factorial design as multivariate technique. Gas-phase experimental 1H chemical shifts of 18 alcohols were used to establish the best levels of theory for obtaining 1H chemical shift, among them the new experimental values of 1H chemical shifts of 10 alcohols were obtained in our laboratory. HF/6-31G(d,p)... 

Aseptic loosening and infection are two major problems of bone implants. Aseptic loosening occurs due to poor cell growth and poor adhesion to the implant surface over time. Bone infection at the implant site occurs mainly by the staphylococcus aureus bacteria. In some cases, infection occurs in the short term and in the early times after implantation, and in some cases, infection occurs in later times. The aim of this study is to synthesize and evaluate antibacterial coatings, while having cell growth-promoting components and cell differentiation to solve bone implant problems simultaneously. Also, the issue of bacterial resistance to antibiotics and their risks in bone implants is another... 

Cane sugar impurities cause reduse production sugar in cane sugar industry.These impurities include polysaccharide for example starch, dextran and inorganic ash constituent such as potassium, sodium calcium magnesium and silica .The amount of impurities in the cane sugar depend on many factors including variety , grooving conditions and regional climate. Removal of impurities from cane sugar juice by clarification is an essential part of process of raw sugar manufacture. This process is based on the addition of lime, phosphates and polyelectrolyte. In this study effect of the amount of lime, phosphates and poly electrolyte on removal of various impurities has been investigated.In addition... 

Nowadays a major part of energy, fresh water and sewer water in over the world are transmitted by buried pipe, and always these lines are under the loads and different stresses such as corrosion, earth quick and etc.
In many countries the age of these lines are more than 30 years which causes corrosion of the pipe wall and the necessity of health investigating of transmission lines has a special importance for the governments and leak detection can also keep the natural environment healthyand the costs will come down significantly, scientists and researchers have always tried different ways to check the health of the pipes.
In the field of leak detection and the problems of age... 

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... 

As nuclear energy continues to be used as a useful energy resource, waste management, especially management of high-level nuclear waste (HLW), will always be a major concern, as the future generations should not be deprived of the valuable benefits of this energy. Vitrification of liquid high-level radioactive waste (HLW) has received greater attention, worldwide, than any other high-level waste solidification process. The high solubility of HLW in borosilicate glass, the controllable temperature of this type of glass and its low leaching rate in repository environment, have introduced borosilicate glass as a suitable host for HLW immobilization. In this project, the immobilization of the... 

Focus of the present research is on the study and cognition of sources of carbonaceous compounds present in PM2.5, particularly secondary organic carbon. For this purpose, two different approaches were used. The first approach investigates the SOA formation from internal combustion engines exhaust and unburned fuel (bottom-up approach). The second approach studies the contribution of each of the primary and secondary sources to PM2.5 mass, whereby secondary organic carbon share is obtained (top-down approach). Modeling SOA formation from vehicles exhaust showed that diesel vehicles have greater SOA formation potential than gasoline vehicles, due to large amount of S/IVOCs present in their... 

Considering the operation of the current nuclear reactors and the country's policy to achieve 10,000 megawatts of nuclear power in the horizon of 1420, as well as the construction of research reactors, we will face a huge amount of radioactive waste in the coming years. Meanwhile, spent ion exchange resins constitute a large amount of low and intermediate level (LILW) solid radioactive waste produced from the nuclear industry. Therefore, appropriate precautionary measures should be taken for the immobilization and disposal of these radioactive wastes in order to ensure the sustainable development of the nuclear industry and the protection of the environment and human health. In this study,... 

Moderate and Intense Low-oxygen Dilution(MILD) is the new member of combustion field. Highly preheated reactants and lowering the oxygen level in MILD combustion has some promising advantages. In this study the MILD burner, Jet-in-Hot-Coflow(JHC), is taken as the main test case. In this Research, Eddy Dissipation Concept combustion model ,introduced by Magnussen et al,is investigated in detail and governing equations are re-extracted. EDC combsution model due to moderate compuational cost in comparison with other combustion model and well prediction ability has drawn attention. Simulations on the Jet-in-Hot-Coflow(JHC) has shown the promising performance of the EDC combustion model. It seems... 

In this thesis, reactivity controlled compression ignition (RCCI) combustion fueled by diesel and natural gas is experimentally and numerically investigated. Natural gas as a fuel with low reactivity is injected into the intake manifold, and diesel as a fuel with high reactivity is injected directly into the combustion chamber. One of the main goals of this thesis is to experimentally examine the effect of important parameters on combustion phasing control, operational range extension, and pollutants. Natural gas is one of the important sources of energy in Iran and the world. Using natural gas in internal combustion engines can cause methane to slip into the atmosphere and intensify the... 

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... 

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... 

The role of a mathematical model is to explain a set of experiments, and to make predictions. In setting up a mathematical model of a biological process, by a set of differential equations, it is very important to determine the numerical value of the parameters. For biological processes are typically valid only within a limited range of parameters. In the last decades, various cancer models have been developed in which the evolution of the densities of cells (abnormal, normal, or dead) and the concentrations of biochemical species are described in terms of differential equations. Some of these models use only ordinary differential equations (ODEs), ignoring the spatial effects of tumor... 

Whenever continuous and discrete dynamics interact, hybrid systems arise. Basically, models of such systems consisted of differential or difference equations to represent continuous dynamics and automata or other discrete variables to describe behavioral mode of the systems. Our main concern is focused on two types of hybrid systems: Discrete controllers which are combined with continuous physical process like biological systems can often be well described by hybrid systems. Our approach in this thesis deals with optimal multiple daily insulin injections which are introduced as an offline control approach on a simulated patient with type I diabetes. Simulated patient is provided via GlucoSim... 

Molecular communication (MC) is a relatively new branch in telecommunication science. This branch is designed to transmit information in small environments (about nanometers). Applications of molecular communication include identification of abnormalities, detection of cancers, etc. The smallness of the transmission environment has caused new challenges and areas in this field. One of the unique features of MC with no parallel in classical wireless communication is chemical reactions: different types of molecules can react with each other and form new types of molecules in the medium. This feature of MC poses a challenge in macroscale MC since equations describing chemical reaction with... 

In this research, a comprehensive numerical model for Thermo-Hydro-Mechanical and Chemical multiphysics problems in fractured porous media was introduced using the eXtended Finite Element Method (XFEM), and its efficiency was demonstrated in two-dimensional problems. For the simplicity of the formulation and according to the common assumptions in the corresponding fields of study, the solid phase was assumed linear elastic and the flow was taken into account via Darcy's law. The system of governing equations comprised the linear momentum balance of the solid phase, mass conservation of pore fluids, thermal energy balance, and mass conservation of chemical species. The coupling of these... 

This study investigates three-dimensional modeling of nanodroplets over chemically patterned surfaces. The pattern can be established by changing the contact angle on the surface. The problem is studied numerically by solving the thin film equations.Both the long-range and short-range inter-molecular interactions are considered. The numerical procedure is validated by using the theoretical studies. The effects of parameters such as the size of the droplets, the gradient of the surface, and the slip coefficient on the dynamics and speed of droplets and the shape of them during the motion are inspected.By examining the dynamics of the system it is revealed that the velocity of the droplets...