Sharif Digital Repository

Synthesis and characterization of Nafion/TiO2 membranes whit different solvent (DMF, DMAc, NMP) for proton exchange membrane fuel cell (PEMFC) were investigated in this study. Nafion/ TiO2 nanocomposite membranes have been prepared by solution casting Method. The structures of membranes were investigated by Scanning Electron Microscopy (SEM). Also water uptake, proton conductivity and ion exchange capacity (IEC) of membranes were measured and compared whit Nafion 112 in microbial fuel cell. The membrane was prepared whit DMF solvent has maximum proton conductivity and best morphology and maximum cell voltage  

Early detection of prostate cancer using biosensors has been a subject of research for nearly two decades due to its critical importance. The timing of detection plays a crucial role in determining treatment success rates. However, a significant limitation of these studies has been the cost and limited sensitivity of the sensors. In this research, various treatments used in biosensors were compared and necessary parameters to develop a sensitive, low-cost sensor have been subject of optimization. For this reason, we used pencil graphite and graphite sheet electrodes, both of which have potential for low-cost production on a large scale. Additionally, we tested graphene oxide, amine-treated... 

Business Processes are a set of activities which is designed for produce specific output for specific customer or market. Nowadays business processes have a significant role in organizations and they progress to mechanized business processes and transform them to executable workflows. Existence of complex domains with particular requirements from one hand and scale of business projects on the other hand, make existing business processes, which only consider structure and flow of work, are not enough for fulfillment of organizational requirements. By provision of semantics into business processes, which Semantic Web technologies is used in them, business processes become more flexible and... 

The goal of this research is to elucidate the mechanism of Cell recognition in molecularly imprinted polymers (MIPs) using already utilized techniques. Our approach employs a more flexible non-covalent imprinting method which starts from a readily available polymer and utilizes an aqueous environment for both MIP synthesis and testing. Cell MIPs against MG-63 cell were synthesized. The synthesis procedure was optimized to obtain better binding characteristics to the targeted cell. Adsorption of target cell onto imprinted Alginate Spheres was facilitated by these macromolecular fingerprints as revealed by various microscopical examinations The imprinted Spheres showed high selectivity toward... 

Due to largre number of patients treated by dialysis and its significant increasing progress, dialysis efficiency and patients' life quality are of great interest.Dialyzer, the dialysis beating heart, has the role of cleaning blood by removing toxic solutes and balancing volume of bood's water through hollow fiber membranes. In this thesis, firstly we tried to focus on performance characteristics of dialyzer by studying effective parameters influencing dialyzer efficiency and ultimately we set two important performance characteristics, ultrafiltration coefficient and solute clearance, as our goal parameters for evaluating dialyzer's yield. To this purpose, we designed an experimental set... 

Platelet-rich plasma as a juvenile to the narrow repertoire of orthopedic medicine, has risen hope to attain a generic autologous regenerative formula for different conditions. Vast plethora of GFs, cytokines and chemokines has endowed PRP with excellent regenerative properties, however not all of them would favor different conditions. Vascular endothelial growth factor has been demonstrated to be involved in the progress of Osteoarthritis by amplifying the catabolic processes which deteriorate the extracellular matrix of cartilage. Though cumbersome, the result of eliminating VEGF from platelet lysate would be promising. VEGF isolation from platelet lysate requires selectivity. By employing... 

After passing many iterations of tests, video games still suffers from major bugs after they’ve been released. One of these problems is the incompatibility between the video game and target audience’s computers. In this thesis, we have proposed a testing strategy by utilizing Cloud Computing infrastructure for video games and Deep Convolutional Neural Networks. We used a simple algorithm to make the graphical output of a video game partially deterministic and thus it’s possible for us to compare different instances of the game in Draw Call level. We’ve used two separate Deep Convolutional Neural Networks for 1. detecting visual artifacts in frames and 2. comparing pairs of Draw Calls for... 

The aim of this study is the fabrication of 3D porous PCL scaffolds contain core-shell fibers for cartilage tissue engineering. The novel fabrication method is co-axial wet electrospinning simultaneously. These tablets like scaffolds have superior porosity and pore sizes for cell culturing and cell-cell interaction as they have good mechanical properties for cartilage tissue engineering in comparison to 2D electrospun scaffolds. The structure of these 3D scaffolds is mimicking the ECM of cartilage. This study presents the coaxial electrospinning of PCL nanofibers encapsulated with bovine serum albumin and platelet rich plasma for demonstration of controlled release and bioactivity retention,... 

Cancer is a class of diseases characterized by out-of-control cell growth. Cancer is among the leading causes of death worldwide.Cancer modeling is increasingly being recognized as a powerful tool to refine hypotheses, focus experiments, and enable predictions that are more accurate.We investigate a three-dimensional multiscale model of vascular tumour growth, which couples blood flow, angiogenesis, vascular remodelling, nutrient/growth factor transport, movement of, and interactions between, normal and tumour cells. We constructed a hybrid multi- scale agent-based model that combines continuous and discrete methods.Each cell is represented as an agent. The agents have rules that they must... 

Thyroid gland is one of the important internal organs of the body that is responsible for T3 and T4 hormones secretion. Concentration of these hormones directly influences growth of body, thus measurement concentration of thyroid hormones is one of the most common experiments all of the world, specially in our country that Hypothyroidism is common among people. Secretion of hormones in thyroid gland controlled by TSH (thyroid Stimulating Hormone) that released from Pituitary gland. TSH concentration is opposite of level of thyroid secretion. Because of interconnected relationship between these three hormones, measurement of each of them is so important. Many researches for developing... 

Corneal diseases are one of the most common causes of blindness worldwide. The most common way to treat these diseases is to replace the damaged cornea with the donor cornea by corneal transplant. But limitations such as donor tissue deficiency, the risk of disease transmission and transplant rejection have made treatment of these diseases very difficult. A cornea made by tissue engineering can be used as a suitable alternative because of the limitations mentioned for corneal transplantation with donated tissue. At the same time, similarity of the scaffold to normal corneal tissue, both in terms of matrial and structural properties, is essential for proper repair of this scaffold by cells... 

Drug delivery systems (DDS), which, are sensitive to tumor medium have high importance. one of the most important problem of current treatment of cancer is damage of the normal tissue, which, it is expected to solve by smart drug delivery systems. In such cases, one or more features of cancer medium cause to release of the drug. One of features of cancer medium is high concentration of reactive oxygen species and hydrogen peroxide in the most common between them. The purpose of this study is to build a drug delivery system, which it is sensitive to hydrogen peroxide. This carrier has 4 main parts. The first part is anti-cancer drug, which, it is located in the carrier. Second part is... 

The main goal of petroleum reservoir simulation is finding of Pressure (P) and Saturation (S) of fluid in different places of prose media environment of the reservoir in a specific time interval. In this project we will implement a distributed reservoir simulator of a cluster. In fact parallelization of reservoir simulator is finding a method to decompose the reservoir domain into some region and assigning each region to a computer in a cluster of parallel computers in order to minimize the total amount of dependency of regions to each other and messages between nodes in the parallel network according to fluid equation in the system and finaly minimize' the duration of simulation. In this... 

The ongoing Covid-19 pandemic has driven our attention to a simulation of virus dispersion to complete our understanding of airborne transmission. A myriad of studies have shown that respiratory diseases such as MERS, SARS, and COVID-19 can be transmitted by virus-laden droplets released during coughs, sneezing, and normal breathing. To mitigate and prevent the spread of such infectious diseases, investigation of the transmission routes is of great importance. This study has been fueled to harness the CFD tool to simulate the virus-laden droplets dispersion in hospitals inwards. Because of the limitations intertwined with experimental works such as the risk of infection of experimenters, and... 

The emerging blockchain technology has introduced a new approach in today's industry, creating new opportunities in technical, financial, and economic domains. With the emergence of blockchain-based platforms such as Ethereum and the capability of smart contracts, the possibility of creating decentralized systems has arisen. One of the most popular decentralized systems in the realm of finance is crowdfunding platforms that assist technical and academic projects in need of capital for industrialization. Startups or research-academic projects secure the necessary funding by selling initial offering tokens to both small and large-scale investors. In this research, we aim to present an... 

In the pas few years, the use of web-based education systems have grown exponentially spurred by the fact that neither students nor teachers are bound to a specific location and that this form of computer-based education is virtually independent of any specific hardware platforms. These systems can offer a great variety of channels and workspaces to facilitate information sharing and communication between participants in a course, let educators distribute information to students, produce content material, prepare assignments and tests, engage in discussions, manage distance classes and enable collaborative learning with virtual classroom sessions, forums, chats, file storage areas, news... 

The aim of this project is to design and build degradable in-situ injectable hydrogels used for encapsulating and delivering bioactive agents, such as drugs, growth factors play a vital role in cartilage tissue repair. Among these bioactive agent platlate lysate act the important role in healing. Designing novel hydrogels which provide perfect mechanical properties are essential for carriers used for cartilage repair. The method is an enzymatic method based on incorporation of a mixed cocktail of tyramine, hyaluronic acid and heparin. Using different ratios of the mentioned materials will enable us to tailor gels with different mechanical properties. To evaluate the potential of our hydrogel... 

Tumor markers are substances that are naturally found in blood and other fluids in body, but in abnormal conditions such as cancer and metastasis, their level increase. The aim of researching about tumor markers is to find a way for discovering cancer only with a blood test and replace with the current methods such as ELISA, and any type of cancer can be detected by these tests. In this study, molecular imprinted polymers were synthesized with biomolecules. To do that, silica microparticles were used as solid base and after functionalizing their surface, a thin film of polymer was synthesized on them. To optimize the components concentrations and the polymer thickness on the silica surface,... 

In this researh, we study the problem of profit maximization using viral marketing in social networks. In our model, the individual’s ultility value consists of two parts: a private utility and a value obtained by effects of other network members. Each member selects the service that maximizes its utility and Server can exhibit services in different qualities. First we focus on the problem from the Game Theory viewpoint and discuss on the existence and optimality of equilibrium. Next, we show that finding the best equilibrium is NP-hard. For the case of two services, we show that while P ̸= NP, no approximation algorithm with factor better than 2 exists for this problem. Finally, we try to... 

As diseases of eye’s posterior segment has got widespread outbreak in the world, the selection of treatment is very important. Until now, intravitreal injecton has been the most common way of drug delivery to the posterior segment. Although this method is effective, halflife of some drugs in the vitreous cavity, especially those with low molecular weight, is just about some hours. Therefore, it is necessary to repeat injection in order to maintain drug concentration level of the posterior segment in the desired level. Intravitreal injection is invasive and may cause severe adverse effects such as vitreous hemorrhage, retinal detachment, endophthalmitis and cataract. In order to decrease the...