Sharif Digital Repository

Cancer has been known as one of the main reasons for disease-related deaths in the last decades. Early diagnosis could significantly reduce the level of fatality chances. Among the known cancer types, lung cancer is one of the most malignant ones. The common diagnosticmethods are expensive and using high-technology methods; therefore, the introduction of simple and cheap methods is very urgent to detect it. In this project, surface and interfacial tension measurement of cancerous and normal lung cells have been investigated as an easy detection technique. Among the common measurement methods, Pendant Drop and Capillary height techniques have been utilized in this research work. The obtained... 

According to human needs and in line with the development of advanced technologies, different biomedical Engineering fields like hard tissue implants are growing rapidly. Despite significant biotechnology Developments in recent years, some problems to the recognition of implants related osseointegration phenomena persist. The deficient osseointegration and implant-associated infections are key issues for the long-term clinical success of titanium and titanium alloy implants, while development of multifunctional surfaces that can simultaneously overcome these problems remains highly challenging. Therefore, the ultimate goal of this paper was to improve bone cell attachment and simultaneously... 

Mobile and wireless services industry has been among the most attractive businesses recently and is progressing at a fast pace. In this huge industry various organizations and entities cooperate to deliver value to the end user. The mobile operator plays the pivotal role in this chain. Hence mobile operator’s market was chosen in this study as the representative of the industry. Market segmentation and customer satisfaction are the main topics of this study.
Market segmentation for MCI was done using data mining with two-step algorithm. Input data included the consumer behavior extracted from mobile post-paid bills. The results indicated five distinctive clusters. The next part included... 

Titanium dioxide, due to its specific semiconductive properties, has been a highly investigated material for a variety of applications including gas sensors, hydrogen generation by water photoelectrolysis, photocatalysis, dye-sensitized solar cells and purification of water and air. Several recent studies have indicated that titania nanotubes have improved properties compared to any other form of titania for mentioned application. Titania nanotubes have been produced by a variety of methods including deposition into a template and hydrothermal processes. Anodic oxidation of titanium foil in a fluoride-based solution is one of the best methods to produce of titania nanotube arrays. Highly... 

In this study, aqueous two-phase systems (ATPS) containing Tween 20 as a biocompatible nonionic surfactant and three different salts (NH4HPO4, NH4CH3COO and Mg(CH3COO)2 ) were prepared and their extractive potential for Lysozyme enzyme was evaluated. These systems have surfactant-rich top phase and salt-rich bottom phase. Phase equilibrium diagrams at 23 ° C were obtained by using the cloud point method and the results were successfully fitted to the Merchuk correlation and their trends were correlated with the effective excluded volume (EEV) parameter. Afterward, the partitioning behavior of the lysozyme and its extraction efficiency in the systems of Tween 20/diammonium hydrogen phosphate,... 

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... 

Dietary CLA production for medicinal purposes needs a safe and selective process. Biological production methods meet this goal. In this study, the microbial species that was suitable for CLA production was selected; then the CLA produced by bioconversion methods was utilized to produce CLA-enriched triglycerides by trans-esterification. Also the biochemical kinetics of CLA production and esterification reactions to produce CLA-enriched triglycerides was studied. In the presence of two substrates, the kinetics of enzymatic reaction was studied. Then the factors influencing on the microbial yield and CLA production including reaction conditions (reaction time, cell concentration and substrate... 

Mechanosensitive (MS) channels are ubiquitous molecular force sensors that respond to a number of different mechanical stimuli including tensile, compressive and shear stress. One of the main mechanisms to functionally study these channels is the patch clamp technique. Here we use continuum mechanics to probe the question of how curvature, in a standard patch clamp experiment, at different length scales (global and local) affects a model MS channel. Firstly, to increase the accuracy of the Laplace’s equation in tension estimation in a patch membrane and to be able to more precisely describe the transient phenomena happening during patch clamping, we propose a modified Laplace’s equation. In... 

In this work, partitioning of amino acids such as glutamic acid, phenyl anine and tryptophan in aqueous and ionic liquid phases at 298.15 K and atmospheric pressure was measured. [C4mim][Tf2N] is used due can produce two phase with water rapidly. Studying the effect of liquid solution pH on amino acids partitioning shows that increasing of pH results in decreasing of amino acid partitioning coefficient. This phenomenon pertains to electrostatic interactions between cation of amino acid and anion of ionic liquid which reduces when pH increases. Considering the effect of pH, liquid-liquid equilibrium data of amino acids was obtained in a pH that owning maximum partioning coefficient. Chemical... 

Diabetes mellitus is a global endemic that is rapidly increasing prevalence in both developing and developed countries. Recently, the American Diabetes Association has recommended the hemoglobin A1c as a possible substitute to fasting blood glucose for diagnosis of diabetes because it is an indicator of long-term glycemic control. Also, centrifugal microfluidics systems have a good potential to be used in the point of care testing systems. In this study, two centrifugal microfluidic discs were designed and manufactured in order to separately measure the hemoglobin and hemoglobin A1c in the whole blood. In the first part of the study, the hemoglobin measurement disc consists of two chambers... 

Laser ultrasonic is a novel method for measuring sheet parameters. In this technique an intense pulse is irradiated to the target which instantaneously vaporizes the surface layer into the high temperature and high pressure plasma. Expansion of plasma produces shock wave that propagates through the surface. Mechanical properties of target can be calculated by measuring and analyzing produced shock wave. In this project wave propagation is simulated using finite element and numerical-computation methods. The numerical-computation simulation was performed using lamb wave equations. ANSYS software was employed for finite element simulation. The results corroborate each other. Next, simulation... 

Nowadays, autonomous underwater vehicles (AUVs) are implemented to carry out various activities under water. Amongst applications of these vehicles we can mention monitoring of marine creatures, mine installation and neutralization, and many military applications. The objective of this research is designing a control algorithm for underwater vehicles such that an under actuated vehicle can reckon a moving target as a reference and whilst chasing it, vehicle can keep a fixed distance from this target. First the dynamics of underwater vehicles are modeled and in this modeling different effects due to under water motion such as drag force, buoyancy force, and also added mass are included... 

In this paper, the general research of impedance control is addressed for a robotic manipulator with a moving flexible base. Impedance control imposes a relation between force and displacement at the contact point with the environment. The concept of impedance control of flexible base moving manipulators (FBMM) is rather new and is being considered. The dynamic of manipulator is decomposed into slow and fast dynamics using singular perturbation method. New sliding mode impedance control method (SMIC), using an element on the end effector is proposed for high precision impedance control of FBMM. The sliding mode impedance control method as a robust impedance control law is derived for the... 

The reflective optical rotary encoders are used greatly in automation systems for speed and position measurements. Their approach of reading code as pulses which results in position and speed information is very similar to what a CD-ROM driver performs to read the saved data as pits and lands on the compact disc data layer. Moreover, the micron size of pits and lands in compact disc promise a high-resolution, and low cost rotary encoder based on CD-ROM technology. In this thesis, two concepts of length coding and hybrid incremental-absolute coded discs are proposed. To verify the implementation of these concepts, the rotary encoder set based on CD-ROM technology is designed and tested. It... 

The main objective of this project is to investigate modeling for a robotic swarm with suitable sensors and to analyze effect of sensory noise on the control and unity of the swarm. This project is an extension of analytical study done by S. Etemadi, A. Alasty and G. Vossoughi in Sharif University of technology. The flocking frame assumed to have a leader robot that controls over all behavior of the swarm made of agents’ robots with limited equipments and low intelligence that only obey some basic attraction and repulsion laws that will be explained. As an initial step of the analysis, we investigate proper physical model, sensors and navigation systems suitable to the model. Next, the... 

Modeling and Control are fundamental issues for fish robots, which can play basic roles in design, optimization, fabrication, and eventually utilization of them. A review on the literature reveals the shortage of an analytical closed form model with little simplifications and high precision, and also control works based on such models. Studying LAEBT theory, it is shown that this theory is suitable for determining the forces produced due to the tail movements considered in the present work, and then it is used to determine the forces. Experimental investigations by means of the setup made for this purpose showed that the obtained equations for the forces have got acceptable precision.... 

Temperature noise phenomenon in nuclear reactors results to the vital information about the system. This phenomenon may originate from coolant inlet temperature fluctuations, coolant fluid velocity fluctuations or the reactor power fluctuations in PWR reactors. Diagnosis of such temperature noise sources shall improve the reactor control and protection.The present research aims to develop a software to model the temperature noise in the axial direction of a single channel comprises of fuel rod and the associated coolant to recognize the type of temperature noise sources. In this regard, research stages are as follows: first the temperature noise caused by three conventional noise sources in... 

The Very-High Temperature Reactor (VHTR) design is one of the six candidates for the Generation IV nuclear reactors. The reactor core type of the VHTR design is either prismatic or pebble-bed. In pebble bed reactors, the core is filled of thousands of graphite and fuel pebbles. Fuel pebbles in these reactors consist of TRISO particles, which are embedded in a graphite matrix stochastically. The reactor core is also stochastically filled up of fuel and dummy pebbles with an unequal ratio. These two stochastic geometries are the so-called double heterogeneous of this type of reactors. In the current study, a... 

This research focuses on the robust mobile robot localization exploiting motion information acquired from an optical mouse operating based on optical flow technology. Most techniques of visual motion measurement are based on the well research discipline called “optical flow”. Theoretically, optical flow as a method of localization can be highly accurate, but it is sensitive to the noise and surface texture/optical characteristics and distance variations between the CCD detector and surface. As one could not achieve acceptable results in practical situations, to handle these problems, we propose to attach an acceleration – gyro (INS) sensor on the CCD detector (optical mouse) to improve the...