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Design and Simulation of Panchromatic Organic Photodetector
, M.Sc. Thesis Sharif University of Technology ; Faez, Rahim (Supervisor)
Abstract
Organic photodetectrors(OPD) are new generation of photodetectors that use of organic materials to convert optical signal to electrical current. Organic photodetectors in recent decade have witnessed significant improvements and many recent research allocated to this photodetectors. This OPD’s have important application so that the inorganic photodetectors have some problems in that application , for example: wide area imagination , biomedical sensors , flexible application and . . . .This work focus on the design and simulation of a panchromatic photodetector that use of new material and have high bandwidth and low dark current. One of application of this OPD is to use in optical...
Adaptive routing in wormhole-switched necklace-cubes: analytical modelling and performance comparison
, Article Simulation Modelling Practice and Theory ; Volume 17, Issue 9 , 2009 , Pages 1522-1532 ; 1569190X (ISSN) ; Sarbazi Azad, H ; Sharif University of Technology
2009
Abstract
The necklace hypercube has recently been introduced as an attractive alternative to the well-known hypercube. Previous research on this network topology has mainly focused on topological properties, VLSI and algorithmic aspects of this network. Several analytical models have been proposed in the literature for different interconnection networks, as the most cost-effective tools to evaluate the performance merits of such systems. This paper proposes an analytical performance model to predict message latency in wormhole-switched necklace hypercube interconnection networks with fully adaptive routing. The analysis focuses on a fully adaptive routing algorithm which has been shown to be the most...
Mathematical performance modelling of stretched hypercubes
, Article 9th International Conference on Distributed Computing and Networking, ICDCN 2008, Kolkata, 5 January 2008 through 8 January 2008 ; Volume 4904 LNCS , 2008 , Pages 375-386 ; 03029743 (ISSN); 3540774432 (ISBN); 9783540774433 (ISBN) ; Sarbazi Azad, H ; Sharif University of Technology
Springer Verlag
2008
Abstract
The stretched hypercube has recently been introduced as an attractive alternative to the well-known hypercube. Previous research on this network topology has mainly focused on topological properties, VLSI and algorithmic aspects of this network. Several analytical models have been proposed in the literature for different interconnection networks, as the most cost-effective tools to evaluate the performance merits of such systems. This paper proposes an analytical performance model to predict message latency in wormhole-switched stretched hypercube interconnection networks with fully adaptive routing. The analysis focuses on a fully adaptive routing algorithm which has been shown to be the...
Empirical performance evaluation of adaptive routing in necklace hypercubes: a comparative study
, Article International Conference on Computing: Theory and Applications, ICCTA 2007, Kolkata, 5 March 2007 through 7 March 2007 ; 2007 , Pages 193-197 ; 0769527701 (ISBN); 9780769527703 (ISBN) ; Nayebi, A ; Sarbazi Azad, H ; Sharif University of Technology
2007
Abstract
The necklace hypercube network has recently been introduced as an attractive alternative to the well-known hypercube. Previous research on this network topology has mainly focused on topological properties and VLSI aspects of this network. In this paper, we propose some adaptive routing algorithm for the necklace hypercubes. The performance of necklace hypercubes using the proposed routing algorithm is then evaluated by means of simulation experiments. Experiments are realized under different working loads and for different network factors. Moreover, a comparison between the necklace hypercube and the well-known hypercube network is conducted. The comparison has been done considering...
Simulation-based performance evaluation of deterministic routing in necklace hypercubes
, Article 2007 IEEE/ACS International Conference on Computer Systems and Applications, AICCSA 2007, Amman, 13 May 2007 through 16 May 2007 ; June , 2007 , Pages 343-350 ; 1424410312 (ISBN); 9781424410316 (ISBN) ; Nayebi, A ; Sarbazi Azad, H ; Sharif University of Technology
2007
Abstract
The necklace hypercube has recently been introduced as an attractive alternative to the well-known hypercube. Previous research on this network topology has mainly focused on topological properties, VLSI and algorithmic aspects of this network. Several analytical models have been proposed in the literature for different interconnection networks, as the most cost-effective tools to evaluate the performance merits of such systems. This paper proposes an analytical performance model to predict message latency in wormhole-switched necklace hypercube interconnection networks with fully adaptive routing. The analysis focuses on a fully adaptive routing algorithm which has been shown to be the most...
Performance modelling of necklace hypercubes
, Article 21st International Parallel and Distributed Processing Symposium, IPDPS 2007, Long Beach, CA, 26 March 2007 through 30 March 2007 ; 2007 ; 1424409101 (ISBN); 9781424409105 (ISBN) ; Sarbazi Azad, H ; Patooghy, A ; Sharif University of Technology
2007
Abstract
The necklace hypercube has recently been introduced as an attractive alternative to the well-known hypercube. Previous research on this network topology has mainly focused on topological properties, VLSI and algorithmic aspects of this network Several analytical models have been proposed in the literature for different interconnection networks, as the most cost-effective tools to evaluate the performance merits of such systems. This paper proposes an analytical performance model to predict message latency in wormhole-switched necklace hypercube interconnection networks with fully adaptive routing. The analysis focuses on a fully adaptive routing algorithm which has been shown to be the most...
Empirical performance evaluation of stretched hypercubes
, Article 22nd International Conference on Advanced Information Networking and Applications Workshops/Symposia, AINA 2008, Gino-wan, Okinawa, 25 March 2008 through 28 March 2008 ; 2008 , Pages 75-79 ; 1550445X (ISSN) ; 0769530966 (ISBN); 9780769530963 (ISBN) ; Sarbazi Azad, H ; IEEE Computer Society ; Sharif University of Technology
2008
Abstract
Stretched hypercube has recently been introduced as an attractive alternative to the well-known hypercube. Previous research on this network topology has mainly focused on topological properties and VLSI aspects of this network In this paper, we propose some deterministic and adaptive routing algorithms for the stretched hypercubes. The performance of stretched hypercubes using the proposed routing algorithms is then evaluated by means of simulation experiments. Experiments are reahzed under different working loads and for different network actors. © 2008 IEEE
Evaluation of the fractured surface of five endodontic rotary instruments: A metallurgical study
, Article Iranian Endodontic Journal ; Volume 11, Issue 4 , 2016 , Pages 286-292 ; 17357497 (ISSN) ; Khalatbari, M. S ; Meraji, N ; Ghorbanzadeh, A ; Sadri, E ; Sharif University of Technology
Iranian Association of Endodontics
2016
Abstract
Introduction: The aim of this study was to compare several metallurgic properties of Neoniti instrument with four other commonly used endodontic rotary files. Methods and Materials: Neoniti A1 (25/0.08), RaCe (25/0.06), Mtwo (25/0.06), Twisted file (25/0.06) and ProTaper Next X2 (25/0.06) were examined by differential scanning calorimetry (DSC) before and after heat treatment at 500°C. X-ray diffraction (XRD) was also performed on the specimens. Furthermore, scanning electron microscopy (SEM) and x-ray energy-dispersive spectrometric (EDS) analyses were carried out on randomly selected fractured files. Results: In SEM tests, dimpled ruptures, characteristic of ductile fracture, were seen in...
Parallel numerical interpolation on necklace hypercubes
, Article 1st Asia International Conference on Modelling and Simulation - Asia Modelling Symposium 2007, AMS 2007, 27 March 2007 through 30 March 2007 ; 2007 , Pages 123-127 ; 0769528457 (ISBN); 9780769528458 (ISBN) ; Sarbazi Azad, H ; Al-Dabass D ; Zobel R ; Abraham A ; Turner S ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2007
Abstract
The Necklace Hypecube has been recently proposed as an attractive topology for multicomputers and was shown to have many desirable properties such as well-scalability and suitability for VLSI implementation. This paper introduces a parallel algorithm for computing an N-point Lagrange interpolation on a necklace hypercube multiprocessor. This algorithm consists of 3 phases: initialization, main and final. There is no computation in the initialization phase. The main phase consists of [E/2] steps (with E being the number of edges of the network), each consisting of 4 multiplications and 4 subtractions, and an additional step including 1 division and 1 multiplication. Communication in the main...
Synthesize of Graphene Nanoribbons with a Non-Zero Energy Band Gap for Inactivation of Alive Cells Using Infrared Irradiation
, M.Sc. Thesis Sharif University of Technology ; Akhavan, Omid (Supervisor)
Abstract
Graphene is a one layer atom thickness and zero energy gap so for using it in nano electronic and transistors baised on graphene it's energy gap should be opened.one of the methods for opening graphene band gap is creating nano scale boundaries or synthesize graphene nanoribbons. One of the new methods for graphene nanoribbon synthesize is longitudinal opening of carbon nanotube. In this thesis graphene nanoribbons synthesize with this method and analyze with AFM and Raman spectroscopy. Carbon nanotubes also have energy gap and IR absorption recently they used for living cell destruction. In this thesis we synthesize graphene nanoribbons and analyzing their optical absorption and use it for...
Fabrication of Graphene/TiO2 Nanowalls as Visible Lights Photocatalysts
, M.Sc. Thesis Sharif University of Technology ; Akhavan, Omid (Supervisor)
Abstract
TiO2 is known as a photocatalyst in near UV-Visible light region with better efficiency compared to other semiconductor photocatalysts. Many attempts have been done to increase the efficiency of this photocatalyst. also, application of 2D carbon nanostructures namely graphene for increasing the photocatalytic activity of TiO2 has shown positive results.
In this research, we first synthesized Graphene Oxide (GO) suspension by exfolation of graphite oxide suspension. then we fabricated TiO2 thin films on glass substrates by so-called sol-gel method. finally we fabricate Graphene Oxide/TiO2 nanowalls composite films as a photocatalyst in visible light. X-ray photoelectron spectroscopy...
In this research, we first synthesized Graphene Oxide (GO) suspension by exfolation of graphite oxide suspension. then we fabricated TiO2 thin films on glass substrates by so-called sol-gel method. finally we fabricate Graphene Oxide/TiO2 nanowalls composite films as a photocatalyst in visible light. X-ray photoelectron spectroscopy...
Fabrication of Graphene-WO3 Nanocomposites as Photocatalyst in the Visible Light Region
, M.Sc. Thesis Sharif University of Technology ; Akhavan, Omid (Supervisor)
Abstract
WO3 is known as a photocatalyst in the visible light region, but with lower efficiency compared to more interesting semiconductor photocatalysts such as TiO2 and ZnO. Many attempts have been done to increase the efficiency of this photocatalyst by incorporating metal and metal oxide nanoparticles or recently carbon nanotubes.On the other hand, application of graphene, as an unrolled carbon nanotube, for increasing the photocatalytic activity of TiO2 and ZnO has shown positive results. Furthermore, it was reported that such semiconductor photocatalysts (and very recently WO3) can photocatalytically reduce the chemically exfoliated graphene oxide sheets under UV-vis irradiation.
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Synthesis of Graphene Nanosheets for Stem Cells Applications
, M.Sc. Thesis Sharif University of Technology ; Akhavan, Omid (Supervisor)
Abstract
Graphene nanogrids fabricated by graphene nanoribbons obtained through oxidative unzipping of multi-walled carbon nanotubes, used as two-dimensional selective templates for accelerated differentiation of human mesenchymal stem cells (hMSCs), isolated from umbilical cord blood, into osteogenic lineage. The biocompatible and hydrophilic graphene nanogrids showed high actin cytoskeleton proliferations that coinciding with patterns of the nanogrids. The amounts of proliferations found are slightly better than proliferation on hydrophilic graphene oxide (GO) sheets, and significantly higher than non-uniform proliferations on hydrophobic reduced graphene oxide (rGO) sheets and polydimethylsiloxane...
Identifying the risks of Iranian Knowledge BasedFirms Using Fault Tree Analysis (FTA)
, M.Sc. Thesis Sharif University of Technology ; Fattahi, Omid (Supervisor)
Abstract
Knowledge Based Firms are considered to be important for the economic development of a country in regards to both employment growth and innovative activity. The latter is believed to contribute significantly to the increase in productivity and therefore the competitiveness of Iran’s economy. This study contributes to the above literature by investigating the factors that are believed to treat the growth of such firms in Iran. The purpose of this study is to identify functional risks of vital signs monitors via Fault Tree Analysis (FTA) method to use as a guide for manufacturers to identify and control hazards. Therefore, 30 knowledge based firms were selected as sample. Then, based on a...
Synthesis of Graphene from Waste by Chemical Exfoliation and Study of It’s Physical Characteristics
, M.Sc. Thesis Sharif University of Technology ; Akhavan, Omid (Supervisor)
Abstract
One atom thick layer of pure carbon in bonded and hexagonal lattice is named graphene. graphene has unique mechanical, optical, thermal and electrical properties and because of these properties has grabbed attention. graphene has been made from high pure graphite by different methods such as CVD(chemical vapor deposition) , chemical exfoliation , micromechanical cleavage and colloidal suspension. through these methods, green methods for synthesis of graphene, using eco-friendly reductants during synthesis of graphene instead of hydrazine and recently using waste(not graphite) are attractive for synthesis of graphene. Following this idea , a group has produced graphene from wastes such as...
The Use of Hydrogen Rich Water for Synthesis of Hydrogenized Graphene and Investigation of Its Properties
, M.Sc. Thesis Sharif University of Technology ; Akhavan, Omid (Supervisor)
Abstract
Graphene is a two dimensional lattice which is created from carbon atoms. Having special feature, it has such various medical usage, for example in diagnosing and treating cancer. Adding a particular factor to graphene could improve their efficiency. In comparis on with graphene itself, graphene oxide and reduced graphene oxide are much more successful in diagnosing and treating than others because of their higher hygroscopic. Recent studies state that hydrogenized combinations including hydrogenized graphene show desired results. Due to its higher hygroscopic and the possibility of adherence to the cells, hydrogenized graphene could be very effective in diagnosing and treating the sarcomas....
A Meta Heuristic Approach for Design of a Network System in Mass Customization
, M.Sc. Thesis Sharif University of Technology ; Fattahi, Omid (Supervisor)
Abstract
This study discusses about mass customization and optimization of supply network in which both goal considering to set the flow of raw material and final product to satisfy the customer demand. The mass customization is more important concept in this study, so that this goal is placed to the first objective. In this research, the model which contained both goal is presented. The model focus on mass customization and try to satisfy various products demand, which constitute 3 kind of speed demands. Each product can satisfy in 3 way: fast, normal, slow.In the first model the new approach present in which the speed affects all of supplying, manufacturing and distributing system. The system try...
Synthesis of Graphene Oxide and Study of its Fluorescence Properties
, M.Sc. Thesis Sharif University of Technology ; Akhavan, Omid (Supervisor)
Abstract
Graphene oxide is a single sheet of Carbon atoms which has been arranged on a two-dimensional honeycomb lattice. Functional groups such as epoxy, carboxyl and carbonyl are located on basal plane and at the edges of graphene oxide and they localize electrons on the surface of graphene oxide and open band gap in its band structure. Pure graphene has zero band gap, so existence of fluorescence properties is unlikely; but graphene oxide has fluorescence properties due to band gap in its band structure. Fluorescence properties of graphene have been used in live cell imaging and drug delivery, so study and increasing of fluorescence properties is significantly important. The purpose of this...
A Novel Reliability Model for Information Technology Web services
, M.Sc. Thesis Sharif University of Technology ; Fatahi Valilai, Omid (Supervisor)
Abstract
The Internet is often used for communication-based applications such as online banking, stock trading, and shopping where service interruption is unacceptable. Thus, analysis of the impact of the failures of hardware, software, and related services’ performance quality of the service provided to users is of importance to designers and managers in these functions. In this study, we developed a strategy to the design of a dynamic combination of file servers with the aim of providing reliability and SLA. At first, we examine the reasons for the violation of service level in file host services and datacenters, and then we introduce the criteria to measure the violation of service level on the...
Development of a novel solution to enable integration and interoperability for cloud manufacturing
, Article 6th International Conference on Changeable, September 2016 through 6 September 2016 ; Volume 52 , 2016 , Pages 6-11 ; 22128271 (ISSN) ; Fatahi Valilai, Omid ; Sharif University of Technology
Elsevier B. V
2016
Abstract
Nowadays, manufacturing enterprises have been faced with a globalized competitive environment. In this fierce condition, Cloud Manufacturing paradigm emerged as a promising concept for competition. It provides effective solutions and tools for manufacturing enterprises to collaborate in globalized market. The revolution that Cloud Manufacturing has created is based on the redefinition of the classic methods to those which are appropriate for todays' modern and globalized manufacturing environments. In parallel with cloud-based revolution, the expansion of internet-based technologies has been started. These technologies previously have been applied in many fields and resulted in...