Sharif Digital Repository

The present study is aimed at the development of a novel approach based on the magnetically improvement of DNA-directed immobilization to prepare a highly efficient sensor for prostate diagnosis. The novelty of this work is in the use of antibody conjugated magnetic nanoparticles via DDI. DNA-modified magnetic nanoparticles are added in solution to capture DNA-conjugated, fluorescently-labeled immunocomplexes formed in solution free of steric constraints. The DDI-based nanoconstructs are then concentrated and immobilized using a magnetic field. Compared to a process in which the immunocomplex directly forms on the sensing surface, the proposed approach provides higher mass transfer and lower... 

Dye-Sensitized solar cells are the third generation of solar cells that have the potential to increase efficiency as much as solar cells of previous generations, along with lower prices. The cathode electrode of the pigmented solar cell as one of the essential components of the cell plays the role of accelerating the oxidation reaction reduction of the electrolyte. Platinum often is used as a catalyst layer. To reduce production costs and maintain cell viability, platinum should replace with other materials at a lower cost and higher electrochemical activity. Recently, carbon materials have been considered for the production of inexpensive solar cells with suitable performance. Among... 

This study investigates and enumerates instances of conflict of interests in some job positions in Iran’s Ministry of Health, Treatment and Medical Education. To achieve this goal, we interviewed people involved in the health field and reviewed job descriptions as well. By adopting the prevalent definition of conflict of interests regarding the duties, authorities, and responsibilities, instances of conflict of interests has been relatively identified in each position. The results show that the main reasons (determinants) for cases of conflict of interests can fall into three categories. First, duties of positions are in such a way that being a shareholder, CEO, and member of the board of... 

An important issue in aerospace propulsion systems is the reacting flow analyses, which involve many different concepts and physics including various chemical reactions mechanisms and radiation and convection heat transfer physics. As known, the computer simulation is a powerful tool to analyze the reacting flow physics in various combusting environments. It can suitably provide details of both chemical reaction occurrences and heat transfer physics. In combustion environments, the temperature gradient is noticeably affected by the density gradient. On the other hand, the accurate modeling of density gradients highly affects the computational results. In practice, the density-based methods... 

Cryptocurrencies (cryptos), as a new type of money, are considered a medium of exchange, an investment asset, and a hedging tool in today's world. In 2008, bitcoin as the first cryptocurrency was introduced, which has survived through recent years and has gained more and more popularity every day. Cryptos are one of the first applications of blockchain, the technology that many expect to revolutionize the future world in different ways. We aim to investigate what affects the bitcoin price, based on artificial intelligence and, in particular, machine learning. First, we find features impacting bitcoin price via a thorough investigation of the literature. Then, applying machine learning and... 

Toxic flow occurs when a trader with confidential information trades with a market maker without that information. The trade price is such that the market maker is obliged to provide the desired liquidity by taking the risk of loss for the order. The PIN (Probability of Informed Trading) is widely used to calculate the amount of toxic flow in a market and evaluate the market condition in terms of informed trading. However, Easley et al. (2012a) propose a new alternative method based on high-frequency data and daily orders called VPIN (Volume-Synchronized Probability of Informed Trading), and we apply it in the Iran stock market. This method can give the market makers the ability to predict... 

In this thesis we evaluate VIC hydrological model’s simulated soil moisture and discharge at Saghez synoptic station, located at ZarinehRood sub basin, Urmia Lake basin in three time periods to overcome observational and satellite data scarcity in the basin. All the input files for this macro scale semi-distributed model chose from satellite data. With a multi-objective calibration algorithm called NSGA-II and utilizing Nash-Sutcliffe (NSE) and R2 as objective functions for discharge calibration and correlation coefficient and RMSE for soil calibration, the model results evaluated. As where as we didn’t have access to observational soil moisture data, we utilized SMAP satellite soil moisture... 

It has always been a human challenge to inspire natural configurations and phenomena and benefit from their merits in improving the performances of man-made proposed aero/hydro vehicles. For example, the manta rays are known for their great swimming performances. To design and fabricate an underwater robot based on the manta ray geometry and its kinematic characteristics, it is important to initially study its hydrodynamic behavior and possibly arrive at some key design parameters, which can remarkably help to figure out an optimum geometry with high swimming performances. The main objective of this study is to focus on the merits of gliding motion inspired by the manta ray fish considering... 

Although the differences between retail and institutional investors in the stock market can have important effects on key processes such as liquidity and price formation in this market, there are significant differences of opinion about how these differences would affect mentioned processes. An interesting question for financial researchers is how the effects of different groups affect the liquidity of the stock market. Liquidity is defined as the ability to carry out transactions with high speed, low cost and without being heavily influenced by the price. In this research, using 10-year stock information (2012-2022) such as order book, price and volume of transactions, we showed that the... 

The accurate assessment of biomarkers likes proteins, hormones or other biomolecules that amount of them changes with state of disease or level of treatment and gives diagnostic information is a difficult duty. In these samples, pathogens exist in small quantity compared to other background molecules. Therefore, appropriate sampling process for concentrating and separating pathogens from the matrix should be developed in order to provide rapid and accurate pathogen detection test. In this thesis design and fabrication of microfluidic biosensors based on the modified nanofibrous membranes were investigated and explained. PES nanofibrous membrane with carboxyl functional groups for covalent... 

There are different kinds of ownership structures. In every economy special kinds of these structures are common. These structures include Pyramidal ownership, cross-ownership, etc. These structures empower shareholders to make a gap between their cash flow right and ownership right in a special firm so they could control more firms with the same capital. These structures have their pros and cons, like the internal capital market and tunneling. Of important factors affecting these structures are Legal protection of minor shareholders, shareholder concentration, and largest shareholder. In this research, we find that, unlike most countries, there is a negative relationship between a firm's... 

Tensors or multi-way arrays are useful tools to identify unknown quantities thanks to the uniqueness of their decomposition. Tensor decompositions have been widely applied to obtain unknown components with physical meanings in many applications such as medical image and signal processing, hyperspectral images analysis, chemometrics, etc.In this thesis, we investigate the application of tensor decomposition for probability estimations, which are required for some targeted data/text mining tasks such as unsupervised clustering of data/documents. Besides criticizing the existing tensor decomposition algorithms for probability estimations, we propose to apply some proper constrained tensor... 

In this study, chitosan-based nanoparticles were prepared due to their biocompatibility, availability, high loading capacity of drug, stimulus responsive behavior and the presence of active functional groups. Chitosan was chemically functionalized with reactive oxygen species (ROS)-responsive moiety to respond to the oxidative stess and endosomal pH in nerve injuries. To prepare nanoparticles, functinalized chitosan ionically gelated with pH-responsive polyanions with ROS-scavenging properties such as polyacrylic acid and hyaluronic acid. Then, pH- and ROS-responsive nanoparticles were used for selective transfection into reactive astrocytes and axonal regeneration in spinal cord injuries.... 

Game theory, renowned for its transformative impact on economic theory, has often remained on the periphery of strategic decision-making within businesses, primarily due to its inherent mathematical complexity. This research offers a novel perspective to address this challenge, particularly in the realm of strategic pricing and revenue management. When analyzing strategic positions becomes challenging due to structural or informational complexities, this study proposes a strategic incorporation of these dimensions into a serious gaming framework. By distilling complex market dynamics into key modeling parameters, an environment closely mirroring real-world scenarios is created. In this... 

In this research, direct synthesis of dimethyl ether (DME) from CO2 hydrogenation in three phase slurry reactor was investigated. Bifunctional catalysts composed of Cu- ZnO-Al2O3-ZrO2 as hydrogenation component and zeolite Na-Mordenite as dehydration component, with different Al2O3 and ZrO2 contents were synthesized by coprecipitating sedimentation and influences of Al2O3 and ZrO2 on CO2 conversion and DME selectivity were evaluated. Results show, both Al2O3 and ZrO2 enhanced conversion, but Al2O3 markedly increase selectivity of DME. However, when the total contents of Al2O3 and ZrO2 was increased up to 16 wt% , CO2 conversion and DME selectivity remarkably decreased. BET and XRD analyzes... 

This thesis presents a variety of methods have been proposed for optimal locating and sizing of Distributed Resource (DR) in restructured power system to reduce congestion and enhance security. Initially three different methodologies, based upon LMP and congestion rent, are presented that form priority list of candidate buses to reduce solution space. For taking into account security, The N−1 contingency criterion is performed and then a priority list of the worst contingencies from congestion rent point of view is organized. Based upon both normal condition and selected contingencies of the network a priority list of buses for optimal placement and for each level of power output of DR is... 

A new structure of implantable neural recording microsystem base on multiple valued logic (MVL) has been proposed. MVL is a new idea for reduction of occupied area and the power consumption of microelectronic. In another side, in implantable microsystems , occupied area and power consumption by this type of micro systems is a challenging problem in this field. Therefore, the problem of power consumption and occupied area can introduce as a prime stage of suggested microsystem completed design of convertor of analog to digital in usage of multiple level in this micro system worked. Design of convertor of analog to digital is a convertor of quaternary successive approximation. And also,... 

In an era of data revolution, information systems (IS) and information technologies (IT) play a vital role in the survival of organisations. However, technology application within organisations does not happen automatically or seamlessly. Various external and internal factors can affect the different stages of the technology adoption process, from decision-making to inter- and intra-organisational diffusion. The investigation of factors that influence the adoption level of various technological solutions in different contexts has been an interesting subject for scholars. This study examines the mechanisms through which various factors affect organisations in the architecture, engineering and...