Sharif Digital Repository

In this research, we focus on study and fabrication of organic inorganic solar cells. We use and optimize various methods such as one-step spin-coating, two-step sequential deposition and vapor-assisted solution process (VASP), to prepare high quality perovskite films. One-step deposition is simplest method for deposition of perovskite films. Although perovskite deposition by this method is very simple, the control of uniformity and surface film morphology is difficult. Chlorine inclusion, optimization of annealing conditions, and a sequential solution-based deposition method have been demonstrated to increase film coverage and uniformity. Hence, we use sequential deposition method for... 

Quantum entanglement and superposition are wonderful and mysterious phenomena of quantum mechanics. By means of quantum entanglement, two or more systems become partner in state of each other . As a result, measurements on each of these systems affect the status of other systems. Quantum superposition allows a system inhabits several of its possible quantum states simultaneously. These two features are applicable in many technologies in present age. Photons, as an quantum unit of light, are appropriate candidate for utilization these properties. Because they are robust to decoherence and for their preparation exist various methods. Hence, we interested to generation of quantum states of... 

Schizophrenia is a devastating disorder that steals the opportunity of having a normal life from the sufferers. Drugs used in treating this disorder usually target psychotic symptoms and do not affect negative symptoms effectively. One of the deficits falling into this category is the impaired reversal learning. These patients usually learn the rules but do not renounce them after the contingencies of reward have been reversed. To investigate the reasons of this impairment, first a hypothesis of how different parts of the brain communicate during reversal learning is proposed using the physiological evidence. Then considering the known relation between the actor-critic model of the... 

The use of renewable energy sources has received much attention due to the increasing need for energy, limited energy resources and the pollution of fossil fuels. Among all types of solar energy conversion technology, photovoltaics has the highest technical potential and Iran’s geographical location is very suitable for benefiting from this energy. So, in this thesis, the fabrication and characterization of nanostructured solar cells based on organic-inorganic perovskites have been investigated. Many research goups have tried to increase the efficiency of perovskite solar cells. The efficiency of this kind of solar cells depends mainly on the light-absorbing layer (perovskite) and its... 

Solar cells, as a part of photovoltaics (PV) industry, have a significant share in the renewable energy market. Perovskite solar cells (PSCs) and thin film solar cells (TFSCs) achieved 23% and 22% power conversion efficiencies (PCEs) respectively. However, the PV industry still faces challenges like “high manufacturing costs” and “stability”. Among the strategies to overcome these challenges are substitution of the costly materials with cheaper, more abundant ingredients along with utilizing inexpensive deposition methods like printing rather than vacuum-based methods such as evaporation and sputtering. Carbon materials attract more attention in the solar cell research community for their... 

Due to the environmental concern for the harmful effect of the release of HFCs on global warming there has been more interest for the use of hydrocarbons as refrigerants in recent years. In this project the performance of these refrigerants have been studied and compared with common refrigerants from the quantitative and qualitative point of view using a real-scale model of Peugeot-405 air conditioning system. Charging amount, inside temperature, cooling load, energy consumption of cycle, coefficient of performance and required time to steady state condition are the important comparative criteria for such a study. After carrying out a series of tests it has been considered that charge... 

Metabonomics is a quantitative measurement of time dependent metabolic interactions for living systems in response to the pathological or genetic variations. NMR spectroscopy has emerged as a key tool for understanding metabolic processes in living systems. In this project, the study of metabolomics was performed as classification and regression on samples of parkinson’s disease, multiple sclerosis disease, celiac disease and crohn’s disease. In classification part, various methods were applied using optimal parameters.classification methods in Parkinson’s disease, multiple sclerosis disease, celiac disease and crohn’s disease were RF, CART, PLS-DA, RF and RF respectively. Based on the... 

Prediction of groundwater level fluctuations is absolutely necessary for the proper manag ement of these precious resources. There are different methods to predict hydrological time series such as groundwater level. Linear models inefficiency in predicting nonlinear and n on-stationary time series cause researchers widely use artificial intelligence techniques such as Artificial Neural Networks (ANN), Fuzzy Inference System (FIS), Genetic Algorithm (GA) and their hybrid models such as Artificial Neural – Fuzzy Inference System (ANFIS). These smart models are capable to simulate nonlinear and non-stationary time series in suitable accu-racy using by a few time and data. By emersion of Wavelet... 

Foundation is the lowest load-bearing part of a structure and a part of underneath soil that is affected by the structure load. In fact, foundation transfers the loads from the superstructure to the substructure, preventing excessive settlement of soil or stresses exceeding soil bearing capacity. Indeed, almost all structures are placed on the ground, therefore the effects of soil and structure on each other, which is known as Soil Structure Interaction (SSI), is considered as a key factor in many important and engineered structures. In contrast to structures on a rigid footing, a flexible foundation may show stiffness degradation along with an increase of damping and natural period of the... 

In this project three models addressed before in the references are reviewed and the stability margins of radome error slope obtained by analytical method. Then a new model who is usefull in practical applications presented. Because of complication of this model the model is simplified and stability margins for radome error slope derived in simplified model. It is also shown that simplified applicative model is similar to model purposed in ref. [6]. Then a PD controller designed to stabilize some of models reviewed in chapter 3. The equations derived before verified in continuation of the project. The effects of parameters on the stability of missile analysed by equations derived in chapter... 

In this research the problem is the development and simulation of Transfer Alignment algorithm for an aerial launch space launch vehicle. In the references there is no complete study on development of this algorithm for the case space launch vehicle. In order to develop the algorithm, the carrying airplane and the space launch navigation systems are considered as the Master INS and Slave INS respectively. First a 6DOF simulation of the airplane is presented. Then the desired inputs for simulation of Master and Slave INS are generated. Also the differences of the inputs of Slave INS caused by the distance between the Master and Slave INS is considered. Master INS performs as an ideal INS and... 

One of the most important issues among defense is the increasing of the defense power using present facilities. Therefore, optimal setting and arrangement of equipment by considering different air-to-earth attack of enemy without knowing of properties and capabilities of available systems may not be possible. So, using defense equipment considering properties of them, and paying attention to existence restrictions and effective elements can have an effective role with the design of suitable algorithm.The main purposes of this thesis are: maximization of the efficiency of a defense system against. aerial invader targets, achieving the best arrangement of defense equipment based on suggested... 

With the increasingly collected biological data, appropriate usage of this data is of great importance for understanding and predicting biological systems and has been the aim of experiments and data collections. A famous category of biological data is known as “omics” which refers to transcriptomics, proteomics, metabolomics, and fluxomics, from different cells or tissues in various media and conditions. This set of data is regularly used for tasks such as studying cells and organisms, understanding cell states, cancer prediction, etc. and is of great importance in Systems Biology.In this thesis, we concentrate on studying cells or organisms using such data, where during that process, we... 

Topological combinatorics is an almost novel branch in mathematics whose dawn began to shine originally from Lovász studies at late 70's. The main purpose of the pursued subjects in this branch is to apply topological methods in order to conclude various combinatorial results based on the famous Borsuk-Ulam's theorem which itself is a very deep statement in algebraic topology and has many equivalent versions. For instance, one of these versions states that there is no continuous map f:S^n⟶S^(n-1) which behaves antipodally. In this thesis, we intend to take a considerably long journey in homology theory to pave the way toward a complete proof of this theorem and some of its generalizations.... 

With the advancement of the space industry and the expansion of space missions, the need for satellites and spacecraft with more precise sensors and equipment has increased, which in turn increases the payload mass. In today's world, designing launch vehicles that are merely suitable for the mission is not enough; the launch vehicle must be the best and most appropriate system. The best launch vehicle system is one that not only performs the mission well but is also cost-effective, has higher efficiency, higher reliability, and is easier to maintain. This project aims to develop a multi-disciplinary launch vehicle design software with a graphical interface. In this project, using a... 

Due to the increasing development of digital systems based on limited energy sources (i.e. battery), energy efficiency has become one of the most important concerns in the design of these systems. The use of multi-core architecture is an effective solution for the problem of reducing energy consumption. Hence using it in digital systems has become more common. In addition, enabling methods for reducing energy consumption on processor, helps in making energy more efficient. DVFS and DPM are the two major methods used for reducing dynamic and static energy consumption of processors. The using of multi-core architecture due to the higher chip density, results the static and dynamic energy... 

Integrated guidance and control (IGC) as a new approach to guidance and control methods has been studied in this thesis. A new approach to nonlinear aerodynamic formulation with backstepping controller has been proposed in order to improve interception. Various curve fitting techniques like Gram-schmidt method has been tested. But finally a planar aerodynamic formulation was used which only varies with angle of attack. Results showed that the proposed method requests smaller control input than the linear IGC formulation and conventional G&C methods, because of more precise knowledge of normal force coefficient. Thus the vehicle experiences smaller angle of attack and normal acceleration.... 

Plan irregularities of structures due to the governing regional and environmental conditions are a pretty important issue from the architectural as well as structural design point of view. Most of the time, especially in mid-rise and/or high-rise buildings with plan irregularities, dual system of Moment Resisting Frames (MRF), accompanied with shear walls are strongly suggested. Considering the previous works and investigations of researchers, reveals not too many studies and researches in this regards; specially, when it comes into new area and application of the Steel Shear Walls (SSW). In the present work, at first it is proposed to model and analyze a MRF steel structure with plan...