Sharif Digital Repository

In this paper, as an application in biometrics, the electrical capacitance of normal and cancerous blood samples is experimentally determined in order to test the null hypothesis that the electrical capacitance of the two samples differs. The samples taken from healthy donors and patients diagnosed with different types of hematologic cancer are examined by a cylindrical capacitor with blood as its dielectric. The capacitance of these samples is measured at room temperature and a single frequency of 120 Hz, well below the frequency where β-dispersion starts, using a simple LCR meter device. The measurements indicate that the capacitance of the blood increases under applied electric field for... 

Treatment of cancer involves many invasive procedures that could be a source of distress in kids suffering from cancer. Distress itself can be an important obstacle in patients' acceptance of treatment and their adaptation to it, consequently reducing its efficiency. Distress symptoms, in a spectrum from mild to critical, are shown to be widespread in children struggling with cancer. In recent years to alleviate this psychological condition, researchers have proposed and examined several methods such as relaxation, hypnosis, desensitization, and distraction. This study presents a new approach to explore the impact of utilizing a humanoid robot as a therapy-assistant in dealing with patients'... 

Treating cancer encompasses many invasive procedures that can be a source of distress in oncology patients. Distress itself can be a major obstruction in the path of acceptance of treatment and the patient's adaptation to it, thereby reducing its efficiency. These distress symptoms have been found to be prevalent in children suffering from cancer, in a spectrum from mild to critical. In the past years in response to this psychological suffering, researchers have proposed and tested several methods such as relaxation, hypnosis, desensitization, and distraction. This paper propounds a new approach by exploring the effect of utilizing a humanoid robot as a therapy-assistive tool in dealing with... 

Identification of different flow regimes in industrial systems operating under two-phase flow conditions is necessary in order to safely design and optimize their performance. In the present work, experiments on two-phase flow have been performed in a large scale test facility with the length of 6 m and diameter of 5 cm. Four main flow regimes have been observed in vertical air-water two-phase flow at moderate superficial velocities of gas and water namely: Bubbly, Slug, Churn, and Annular. An image processing technique was used to extract information from each picture. This information includes the number of bubbles or objects, area, perimeter, as well as the height and width of objects... 

Two-phase flow simulations around a body were not studied before and considering these flows can play a significant role in long-term reliability and safety of industrial systems. In this paper, flow regimes, drag coefficient and void fraction around different cross-section prisms were considered. To achieve this aim, main equations of flow have been developed for investigation of drag coefficient in air-water two phase. Our numerical analyses were performed by a designed and written CFD package which is based on Eulerian-Eulerian approach. Geometries, which have been studied in this article, are: circle, rectangle and triangle, for different aspect ratio (length over width) and leading edge... 

Micro/Nano mechatronic systems might be defined as systems that include nano- or micro-scale components. These components can be sensors, actuators, and/or physical structures. Furthermore, the high-precision control laws for such small scales are important to ensure stability, accuracy, and precision in these systems. In this writing, four categories of such small-scale systems are considered by providing multifarious novel or key examples from the literature: control engineering and modeling, design and fabrication, measurement engineering, and sensor/actuator development. The applications discussed in the examples vary from nano-positioners, crucial in systems such as atomic force... 

In order to safe design and optimize performance of industrial systems which work under two phase flow conditions, it's often needed to categorize flow into different regimes. In present work the experiments of two phase flow were done in a large scale test facility with length of 6m and 5cm diameter. Four main flow regimes were observed in vertical air-water two phase flows at moderate superficial velocities of gas and water: Bubbly, Slug, Churn and Annular. Some image processing techniques were used to extract information from each picture. This information include number of bubbles or objects, area, perimeter, height and width of objects (second phase).Also a texture feature extraction... 

In this study, the flow patterns of air-water, two-phase flows have been investigated experimentally in a vertical mini pipe. The flow regimes were observed by a high speed video recorder in pipes with diameters of 2,3 and 4 mm and length 27, 31 and 25 cm, respectively. The comprehensive visualization of air-water, two-phase flow in a vertical mini pipe has been performed to realize the physics of such a two-phase flow. Different flow patterns of air-water flow were observed simultaneously in the mini pipe at different values of air and water flow rates. Consequently, the flow pattern map was proposed for flow in the mini-pipe, in terms of superficial velocities of liquid and gas phases. The... 

In order to safe design and optimize performance of some industrial systems, it's often needed to categorize two-phase flow into different regimes. In each flow regime, flow conditions have similar geometric and hydrodynamic characteristics. Traditionally, flow regime identification was carried out by flow visualization or instrumental indicators. In this research3 kind of neural networks have been used to predict system characteristic and flow regime, and results of them were compared: radial basis function neural networks, self organized and Multilayer perceptrons (supervised) neural networks. The data bank contains experimental pressure signalfor a wide range of operational conditions in... 

Central Nervous System (CNS) malignant tumors are a leading cause of death worldwide with a high mortality rate. While numerous strategies have been proposed to treat CNS tumors, the treatment efficacy is still low mainly due to the existence of the Blood–Brain Barrier (BBB). BBB is a natural cellular layer between the circulatory system and brain extracellular fluid, limiting the transfer of drug particles and confining the routine treatment strategies in which drugs are released in the blood. Consequently, direct drug delivery methods have been devised to bypass the BBB. However, the efficiency of these methods is not enough to treat deep and large brain tumors. In the study at hand, the... 

Airlift systems (ALS) are widely used in various fields such as petroleum and oil extracting industries. As gas-liquid two phase flow is the main part of the flow through these systems, the analysis of such systems accompanies with problems of two phase flow modeling. However, exergy analysis could be a simple method for modeling of airlift systems. In the present study, an analytical model based on thermodynamic principles has been implemented on each phase to analyze the performance of airlift systems. The experimental data were collected at a large scale multiphase flow test rig for the airlift pump with 6m height and diameter of 50 mm. Finally, irreversibility terms, energy destruction,... 

This study proposes a new method for the detection of a weak scatterer among strong scatterers using prior-information ultrasound (US) imaging. A perfect application of this approach is in vivo cell detection in the bloodstream, where red blood cells (RBCs) serve as identifiable strong scatterers. In vivo cell detection can help diagnose cancer at its earliest stages, increasing the chances of survival for patients. This work combines time-domain US with frequency-domain compressive US imaging to detect a 20-μ MCF-7 circulating tumor cell (CTC) among a number of RBCs within a simulated venule inside the mouth. The 2D image reconstructed from the time-domain US is employed to simulate the... 

Within the compressive sensing (CS) framework, one effective way to increase the likelihood of successful signal reconstruction is to employ random processes in the construction of the sensing matrix. This study presents a 3D holey cavity, with diverse frequency modes, to spectrally code, that is, randomize, the ultrasound wave fields. The simulated results show that the use of such a cavity enables imaging simple or complex targets, such as spheres or the letter E, by only a single transceiver—something that is not possible without the use of a coding structure like the cavity. The effect of noise on imaging results and the size of the targets on the first-order Born approximation (BA) are...