Sharif Digital Repository

A circuit model has been proposed for two-dimensional metallic arrays of metallic square holes located on a homogeneous substrate. Although the proposed circuit model holds true, the surface admittance between the metallic hole array and the cover was erroneously calculated since the presence of the cross-polarization terms had been neglected. Furthermore, there have been mistakes in numerical simulation and in analytical calculations based on the presented formulas. The correct formulation is now given, and erroneous figures are replotted  

Impure rhenium and molybdenum bearing solution was passed through a column of Varian strong base anionic resin for selective adsorption of rhenium and molybdenum ions from the solution. Elution of molybdenum and rhenium was carried out using 2 N NaOH and 0.2 N NH4SCN, respectively. The effect of resin bed height on breakthrough time was investigated. Experimental and theoretical curves were compared with good agreement. The results showed that the behavior pattern of these curves was repeatable and almost constant. © 2006 Elsevier B.V. All rights reserved  

In the present study, the main purpose is investigation of the coatings thickness effect on the fatigue life of AISI 1045 steel. Herein, two different coatings of warm galvanization and hardened chromium have been used on the specimens. Fatigue tests were performed on specimens with different coating thicknesses of 13 and 19 µm. In the high-cycle level, S–N curves are extracted with 13 points for each sample. The results show that the galvanized coating is the most appropriate coating with low thickness, but with significant increasing of coating thickness, the best choice is hardened chromium coating. However, artificial neural network (ANN) has been used as an efficient approach instead of... 

In 1974 Dijkstra introduced the seminal concept of self-stabilization that turned out to be one of the main approaches to fault-tolerant computing. We show here how his three solutions can be formalized and reasoned about using the concepts of game theory. We also determine the precise number of steps needed to reach self-stabilization in his first solution. © Springer International Publishing AG, part of Springer Nature 2018  

Effects of pH, D2EHPA, Cyanex® 272 and Cyanex® 302 on extraction of zinc, manganese and cobalt from a Zn-Mn-Co-Cd-Ni containing solution at the room temperature was comprehensively investigated. Addition of Cyanex® 302 indicated a left-shifting-effect on the extraction curve of zinc, a right-shifting-effect on the extraction curve of manganese and no effect on the extraction of cobalt. Addition of Cyanex® 272 shifted all three curves to the right. Therefore, the most suitable extractant for separation of zinc from manganese was therefore 0.3-0.3 mixture of D2EHPA and Cyanex® 302, and that for separation of manganese from cobalt was pure D2EHPA. The stoichiometric coefficient for the... 

This paper presents the results of an analytical study on the dynamic characteristics of the Shaking Table facilities at Sharif University. This 3 degree of freedom shaking table is driven by 3 servo-control hydraulic actuators, and consists of a 12 ton, 4m×4m×0.6m steel deck. The main objective of this investigation is to identify the degree of flexibility of the deck, and its adverse effects in causing errors in the simulation of seismic effects on different structural specimens. Many frame specimens of different weights and configurations are subjected to seismic motions, and their responses are calculated using FE models. Some of these models were designed to account for eccentric... 

Content-based image retrieval (CBIR) has turned into an important and active potential research field with the advance of multimedia and imaging technology. It makes use of image features, such as color, texture and shape, to index images with minimal human intervention. A CBIR system can be used to locate medical images in large databases. In this paper we propose a CBIR system which describes the methodology for retrieving digital human brain magnetic resonance images (MRI) based on textural features and the Adaptive neuro-fuzzy inference system (ANFIS) learning to retrieve similar images from database in two categories: normal and tumoral. A fuzzy classifier has been used, because of the... 

Content-based image retrieval (CBIR) makes use of low-level image features, such as color, texture and shape, to index images with minimal human interaction. Considering the gap between low-level image features and the high-level semantic concepts in the CBIR, we proposed an image retrieval system for brain magnetic resonance images based on saliency map. The saliency map of an image contains important image regions which are visually more conspicuous by virtue of their contrast with respect to surrounding regions. First, the proposed approach exploits the ant colony optimization (ACO) technique to measure the image's saliency through ants' movements on the image. The textural features are... 

The adverse effect of graphene-titanium oxide composite films (containing sheet-like surface morphology) on Caenorhabditis elegans nematodes (as a model for minuscule animals) was investigated in a solar light-induced photocatalytic process. X-ray photoelectron spectroscopy demonstrated photocatalytic reduction of the chemically exfoliated graphene oxide sheets included in the TiO 2 film. Furthermore, formation of TiC and Ti-O-C bonds in the composite film (obtained through annealing at 450 °C in air) resulted in a substantial delay in the recombination rate of the photoexcited electron-hole pairs and more efficient photocatalytic processes. The composite film showed a type of... 

Content-based image retrieval (CBIR) makes use of image features, such as color, texture or shape, to index images with minimal human intervention. Content-based image retrieval can be used to locate medical images in large databases. In this paper, the fundamentals of the key components of content-based image retrieval systems are introduced first to give an overview of this area. Then, a case study which describes the methodology of a CBIR system for retrieving human brain magnetic resonance images, is presented. The proposed method is based on Adaptive Neuro-fuzzy Inference System (ANFIS) learning and could classify an image as normal and tumoral. This research uses the knowledge of CBIR... 

Content-based image retrieval (CBIR) has been one of the most active areas of research. The retrieval principle of CBIR systems is based on visual features such as colour, texture and shape or the semantic meaning of the images. A CBIR system can be used to locate medical images in large databases. This paper presents a CBIR system for retrieving digital human brain magnetic resonance images (MRI) based on textural features and the support vector machine (SVM) learning method. This system can retrieve similar images from the database in two groups: normal and tumoural. This research uses the knowledge of the CBIR approach to the application of medical decision support and discrimination... 

Multi-site photoplethysmography is an optoelectronic technique that measures changes in blood volume associated with cardiac contraction. Photoplethysmogram (PPG) recording enables researchers to study the vascular and hemodynamic properties of human subjects. Currently, there is no commercial system available in the market to perform multi-channel PPG recording. The measurements can be obtained from fingertips, ear lobes and toes due to their low absorption and high degree of vasculature. The main objective of this project is to develop a suitable data compression algorithm for two-channel simultaneous high resolution wireless PPG recording system. MATLAB software was used during the... 

In the present study, the potential of doxorubicin hydrochloride (DOX)-loaded electrospun chitosan/cobalt ferrite/titanium oxide nanofibers was studied to investigate the simultaneous effect of hyperthermia and chemotherapy against melanoma cancer B16F10 cell lines. The cobalt ferrite nanoparticles were synthesized via microwave heating method. The titanium oxide nanoparticles were mixed with cobalt ferrite to control the temperature rise. The synthesized nanoparticles and nanofibers were characterized using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and vibrating sample magnetometer (VSM) analysis. The DOX loading efficiency and in vitro drug release of... 

Karyotyping, is the process of classification of human chromosomes within the microscopic images. This is a common task for diagnosing many genetic disorders and abnormalities. Automatic Karyotyping algorithms usually suffer the poor quality of the images due to the non rigid nature of the chromosomes which makes them to have unpredictable shapes and sizes in various images. One of the main problems that usually need operator's interaction is the identification and separation of the overlapping/touching chromosomes. This paper presents an effective algorithm for identification of any cluster of the overlapping/touching chromosomes together with the number of chromosomes in the cluster, which... 

In the present work, two cavitation modeling strategies, namely the barotropic cavitation model and the transport equation-based model are applied and assessed for the numerical simulation of inviscid cavitating flows over two-dimensional and axisymmetric geometries. The algorithm uses the preconditioned Euler equations employing the interface capturing method for both the cavitation models. A same numerical solution procedure is used herein for discretizing the governing equations resulting from these two cavitation modeling strategies for the assessment to be valid and reliable. A central difference finite-volume scheme employing the suitable dissipation terms to account for density jumps... 

It is important to distinguish overlapped cell for tracking and segmentation biological cells from images. In this research, a novel or comprehensive method is provided with morphological features of cell and minimum distance for overlapped cells separation (OCS). it's necessary to say that this algorithm is not based on type and number of Overlapped cells. In this presented method based on a distance chart. At first, every cell or rectangle of cell is separated of the original image. Also, multiplex cell is distinguished by using minimum perimeter polygon (MPP) method. Distance chart is achieved on the base of morphological procedure and Computing of cell boundary distance to Cell middle... 

Cell dynamics and motion stages are very important issues in the biological cell investigation in this novel method, we propose a novel method based on Kalman filter and second momentum for tracking cells on Sequential Microscopic Images. In proposed manner at first, we select a cell and cut covering rectangle. in the next step, we predict rectangle center of the cell in Next frame based on a modeling of velocity-acceleration using Kalman filter. The rectangle with triple covering area of previous cell rectangle and predicting center by Kalman filter is considered as a searching area. So, if all objects in the search areas have second momentum error less than threshold, it is selected as a... 

We present an efficient method to control the evolution of unsteady cloud cavitation around the CAV2003 benchmark hydrofoil using passive cavitation controllers so called cavitation-bubble generators (CGs). Cavitation control may be used in many engineering applications, particularly in the marine and turbo machinery field. We first simulated the unsteady cavitating flow around the hydrofoil without CGs using a Partially-averaged Navier–Stokes (PANS) method, and validated the acquired results against experimental data. We coupled the turbulence model with a mass transfer model and successfully implemented it in the open source toolbox OpenFOAM. Next, we studied the effect of different CGs on... 

A seeding-growth approach was used to prepare Au@Ag@Au core double shell nanoparticles which were loaded on a rutile-nanorods/anatase-nanobranches thin film via the impregnation method. The thin film was synthesized on a fluorine-doped SnO 2 substrate via three stages of (i)TiCl 4 treatment, (ii)hydrothermal, and (iii)aqueous chemistry. The photocatalytic capability of the newly developed nanostructure was higher than P25 TiO 2 thin film by 40% under visible light and by 100% under UV light irradiation. Photogenerated charges separation at the junctions of rutile-nanorods and anatase-nanobranches along with localized surface plasmon resonance followed by the hot electron transfer from the...