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abdi-basir--abdullah
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A Comparative Evaluation of Prospect and Hip Hip Hooray English Textbooks
, M.Sc. Thesis Sharif University of Technology ; Jahangard, Ali (Supervisor)
Abstract
The current study aimed at both analyzing and evaluating Prospect course books(2012) with reference to a list of criteria which mainly consisted of: layout and physical appearance, different language skills, vocabulary, grammar, content and supplementary materials. Also a comparison was carried out between Prospect textbooks and Hip Hip hooray 2nd edition (2004) – a globally published ELT textbook taught at many Iranian private language institutes, in the related parts. The study is a qualitative one and makes use of descriptions and comparisons for providing data then content analysis has been used. The results showed that there are some positive points regarding Prospect, including...
Study of the behavior of ultrasonic piezo-ceramic actuators by simulations
, Article Electronic Materials Letters ; Vol. 10, Issue. 1 , 2014 , pp. 37-42 ; ISSN: 17388090 ; Pak, A ; Abdullah, M. M ; Shahidi, A ; Malaki, M ; Sharif University of Technology
2014
Abstract
In recent years, there has been a growing interest in the simulation and analysis of piezoelectric transducers with the he help of equivalent electrical circuit simulations (EECS). This paper has been devoted to study of such approach for two designed and fabricated ultrasonic sandwich transducers. By using analytical analysis, the dimensions of components of the two piezoelectric transducers were determined for the assumed resonance frequencies of 30 kHz and 40 kHz. Then, by using a two dimensional finite element model, and regarding two different modeling techniques for the transducers and by application of a current source which was connected directly to the piezoelectric pieces of the...
Produce of Nano composite Antibacterial Coating of PDMS+TiO2+ Ag3PO4 on 316SS Using Sol-Gel Methods and its Properties
, M.Sc. Thesis Sharif University of Technology ; Afshar, Abdullah (Supervisor)
Abstract
The aim of this research is to create coatings with antibacterial and superhydrophobic properties. To evaluate this, the sourness angle test, bacterial culture and halo diameter test have been used. The results show that 316L stainless steel containing PDMS+TiO2+7%Ag3PO4 coating, which is applied by immersion method on the substrate, has a water contact angle of 152 degrees, the number of bacteria cfu.cm2 is 44000 and the halo diameter is 24 mm. which has the best performance among other examples. In order to increase the adhesion of coatings on 316L stainless steel, first heat treatment was performed and then the samples were placed in H2SO4:H2O2 solution for 1 hour to form its OH- groups...
Investigation And Fabrication Super Hydrophobic Coating On Building Facades
, M.Sc. Thesis Sharif University of Technology ; Afshar, Abdullah (Supervisor)
Abstract
According to the creation of high-rise buildings and structures due to the increase in urbanization and population concentration in cities and attention to the beauty of these structures and the impact of this beauty on the morale of urban people, owners or municipalities costs a lot of money for cleaning the building facade every year. On the other hand, removing contaminants from high-rise buildings facades is difficult and lifethreatening. Today, with the advancement of science and the use of self-cleaning super hydrophobic coatings, many of these costs, as well as threats to life, can be prevented. On the other hand, protection of ancient structures as a cultural capital of a country,...
Design and manufacturing of a constant volume test combustion chamber for jet and flame visualization of CNG direct injection
, Article Applied Mechanics and Materials ; Volume 217-219 , 2012 , Pages 2539-2545 ; 16609336 (ISSN) ; 9783037855027 (ISBN) ; Ahmadisoleymani, S. S ; Abdullah, A ; Asgari, O ; Rezai, F
2012
Abstract
Constant volume transparent test combustion chambers are extensively used for investigating injection and fuel burning properties of various combustion engines. Their configuration depends on the engine type and the research purpose. Material of components, shape and dimensions of the chamber and its parts, ease of use, accessibility, sealing and safety of the assembly are the parameters needed to be considered in designing the test cell. This paper explains, structural design of a test combustion chamber and its optical windows using finite element analysis of ANSYS 12.0 software for bearing high pressure variations and thermal shocks of combustion. It was designed for conducting CNG direct...
Synthesis and characterization of porous PZT-PCN ceramics
, Article Journal of Ceramic Processing Research ; Volume 16, Issue 5 , 2015 , Pages 572-577 ; 12299162 (ISSN) ; Nemati, A ; Bagheri, R ; Sharif University of Technology
Hanyang University
2015
Abstract
Porous PZT-PCN ceramics were fabricated with this formula, “0.8 Pb(Zr1/2Ti1/2)O3-0.2 Pb(Co1/3Nb2/3)O3”, abbreviated as “PZTPCN” by introducing Polyvinyl chloride(PVC) and stearic acid (SA) as pore forming agents (PFA) with varied percentages (5, 10 and 15 wt%). The optimum sintering procedure was designed according to the thermogravimetric analysis of pore formers. XRD and FESEM were applied to study the formed phase and the microstructure of the system. Electrical Characterization was conducted using Piezo meter. A decrease in density reduced longitudinal piezoelectric coefficient (d33) and relative dielectric constant (ε) and enhanced hydrostatic figure of merit (dhgh) of PZTPCN ceramics....
Dielectric and piezoelectric properties of porous PZT-PCN ceramics sintered at different temperatures
, Article Materials Letters ; Volume 151 , July , 2015 , Pages 85-88 ; 0167577X (ISSN) ; Nemati, A ; Bagheri, R ; Sharif University of Technology
Elsevier
2015
Abstract
Abstract Porous lead zirconate titanate-lead cobalt niobate 0.8Pb(Zr1/2Ti1/2)O3-0.2Pb(Co1/3Nb2/3)O3 (PZT-PCN) piezoelectric ceramics were fabricated by introducing pore-forming agent polymethyl methacrylate (PMMA), and the effect of sintering behavior on their microstructure, dielectric, and piezoelectric properties were investigated. The optimum sintering procedure was designed according to the thermogravimetric analysis of pore former. Finally the electrical properties were measured. The porosity of PZT-PCN ceramics decreased and the grain size increased with an increase in the sintering temperature at a fixed PMMA addition. "An increase in density with sintering temperature from 1050 to...
Comments regarding: Pereira SA, Lopez M, Lavado N, Abreu JM, Silva H. A clinical risk prediction model of orthodontic-induced external apical root resorption. Revista Portuguesa de Estomatologia, Medicina Dentária e Cirurgia Maxilofacial 2014;55(2):66-72
, Article Revista Portuguesa de Estomatologia, Medicina Dentaria e Cirurgia Maxilofacial ; Volume 56, Issue 3 , 2015 , Pages 141-142 ; 16462890 (ISSN) ; Sharif University of Technology
Elsevier Doyma
2015
Investigation of engine's thermal management based on the characteristics of a map-controlled thermostat
, Article International Communications in Heat and Mass Transfer ; Volume 135 , 2022 ; 07351933 (ISSN) ; Hosseini, S. A ; Nasrollahnezhad, S ; Jahangiri, A ; Rosen, M. A ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
New concepts and strategies are continually being investigated to meet fuel efficiency targets for new generations of internal combustion engines. Thermal management methods can reduce fuel consumption by up to 4%. One approach for thermal management is a map-controlled thermostat. In the current work, this concept is investigated through a benchmarking approach and a methodology for deriving the response time curve for this type of thermostat. To better explore the benchmarking idea, characteristics of map-controlled thermostats for two different engines are identified, analyzed, and compared. Finally, the effects of two separate map-controlled thermostats on the average fuel consumption of...
Assessment of competitive dye removal using a reliable method
, Article Journal of Environmental Chemical Engineering ; Vol. 2, issue. 3 , September , 2014 , p. 1672-1683 ; Bastani, D ; Abdi, J ; Mahmoodi, N. M ; Shokrollahi, A ; Mohammadi, A. H ; Sharif University of Technology
2014
Abstract
In this study, a reliable and predictive model namely, least-squares support vector machine (LS-SVM) was developed to predict dye removal efficiency. Four LS-SVM models have been developed and tested using more than 630 series of experimental data which were obtained from our previous paper. These data consist of adsorbate type, adsorbent dosage, initial dye concentration, salt, absorbance time and dye removal efficiency. Direct Red 31 (DR31), Direct Green 6 (DG6) and Acid Blue (AB92) were used as a model dyes. The results show that the developed model is more accurate and reliable with the average absolute relative deviation of 0.678%, 0.877%, 0.581% and 0.978% for single systems and...
Risk Breakdown Structure (RBS) Identification and Designing for projects
, M.Sc. Thesis Sharif University of Technology ; Sepehri, Mehran (Supervisor)
Abstract
To actualize and making the outputs of a project effectual, it is necessary to conduct an effective management during a project. This case may not be possible without accurately planning for activities, management and controlling all phases of a project ignoring the risk management of that project. If risks of a project cannot be detected before conducting a project, it is possible to challenge the performance and even effectiveness of the project. In current conditions, the most important problem of managers and executives of construction projects through the country is risk management of projects, not acknowledging with definitions of risk, models of risk management and lack of a model for...
Entanglement and Decoherence in Optomechanical Systems Coupled through Photothermal Effects
, Ph.D. Dissertation Sharif University of Technology ; Bahrampour, Alireza (Supervisor)
Abstract
Optomechanical systems have attracted considerable attention in the last decade. Such a raising prominence is mainly due to its capability in providing new insight into the quantum behavior of macroscopic objects and exploring the interface between quantum and classical mechanics. Alongside this fundamental quest, cavity optomechanics has many other benefits, ranging from very precise measurements on forces and positions to quantum information processing. In this thesis, we investigate quantum properties of such systems. Particularly, we study cooling of the mechanical resonator toward its ground state and the entanglement between this mechanical resonator and the cavity field. Cooling the...
High Speed CDMA Communication in Optical Network on Chip
, M.Sc. Thesis Sharif University of Technology ; Hesabi, Shahin (Supervisor)
Abstract
As the number of processing cores on a single chip continues to grow, the need for a high band width, low power communication structure, will be the most important requirements of next generation chip multiprocessors. Today, a major part of power consumption in multi core architectures belongs to interconnects. Due to these facts, reducing consuming power, as well as supporting high performance, is concerned in these architectures. The concept of “network-on-chip” emerged to improve the performance of CMPs. But now a day, considering the circumstances of power budges, it’s incapable of presenting new strategies to decrease consuming power and delay. However, optical interconnects have the...
Clustering Data Streams using Core-Sets
, M.Sc. Thesis Sharif University of Technology ; Zarei, Alireza (Supervisor)
Abstract
We design a new algorithm for clustering data streams in any fixed di- mension, that use the framework of core-set to summarize data, in order to reduce the complexity of computation. Clustering is to separate data into distinct sets called clusters, which objects in the same cluster has the most similarity and objects in the different clusters has the least similarity.This problem has many application in the areas such as: machine learning,image processing, financial and stock transactions. Data stream has recently emerged as an important concept because in many applications, data is inherently streaming over a network or the data base is extremely large and sequential access is way faster...
Some Problems and Methods on Tournaments
, M.Sc. Thesis Sharif University of Technology ; Mahmoudian, Ebadollah (Supervisor)
Abstract
In 1953, Landau expressed the conditions for the existence of tournaments with a prescribed score vector R. Eleven years later, Ryser proposed an algorithm for constructing the tournament matrix with score vector R and showed that any two tournaments with the same score vector can be obtained from one another by a sequence of 3-cycle switches. Last year (2014) Brualdi and Fristcher explained in an article, similar to this process, the existence of, algorithm and switches for loopy tournament and Hankel tournament and similar structure skew-Hankel tournament. This paper is discussed in a chapter of this thesis. In 1991, De Caen found a lower bound for the real rank of a tournament matrix....
An Investigation on the Role of Metal-Organic Framework (MOF) on the Network Structure and Physical/Mechanical Properties of EPDM Rubber
, M.Sc. Thesis Sharif University of Technology ; Molvai, Hossein (Supervisor)
Abstract
Ethylene-propylene-diene monomer rubber (EPDM) is one of the elastomers that shows non-polar behavior, high elasticity at low temperatures, excellent thermal and ozone resistance, and high electrical resistance. In this respect, it is used in various applications such as sealing materials, conveyor belts, waterproof materials, cables, etc. One of the most important applications of this rubber is its use as a sealing material. In this case, the resilience behavior plays an important role in the sealing behavior of the EPDM rubber. Especially in cases such as the car's hydraulic braking system where high service temperatures and dynamic stresses are applied, resilience behavior will be more...
Fabrication of Porous Electrospun Fibe on Biocompatible Polymers such as Polycaprolactone (Pcl) and Thrs Based eir Application in Sample Preparation
, M.Sc. Thesis Sharif University of Technology ; Bagheri, Habib (Supervisor)
Abstract
The aim of this study was to develop a method to determine the trace residual amounts of nonsteroidal anti-inflammatory drugs in meat-related samples and to study the effect of different cooking methods and storage conditions of meat before cooking as an effective factor on the fate of these drugs. To proceed this goal, a nanocomposite was prepared from polycaprolactone nanofiber/silica mesopores as green sorbent by electrospinning. The synthesized nanocomposite was implemented for micro-solid phase extraction of the desired drugs in conjunction with high performance liquid chromatography. Polycaprolactone, due to its excellent physical properties, availability, biodegradability,...
Condition Monitoring of the DC-link Capacitor in Back-to-back Converter Using Main Transient Parameters
, M.Sc. Thesis Sharif University of Technology ; Mokhtari, Hossein (Supervisor)
Abstract
Condition monitoring of a system refers to the process of measuring and analyzing the aging indicators of critical components of a system that can be harnessed to estimate the system’s health. One of the main interests in condition monitoring is to performing the scheduled maintenance activities for the system. Monitoring the status of the system reduces maintenance costs and prevents unwanted contingencies and outages in the system.
In power electronics, the capacitors are the most critical components of the system from the point of reliability. Capacitors are the leading cause of failure in the power electronic converters so, this essay attempts to attain a solution to monitor the...
In power electronics, the capacitors are the most critical components of the system from the point of reliability. Capacitors are the leading cause of failure in the power electronic converters so, this essay attempts to attain a solution to monitor the...
On the design of fir optimum orthonormal filter banks
, Article 2005 IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP '05, Philadelphia, PA, 18 March 2005 through 23 March 2005 ; Volume IV , 2005 , Pages 545-548 ; 15206149 (ISSN); 0780388747 (ISBN); 9780780388741 (ISBN) ; Nayebi, K ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2005
Abstract
The problem of designing optimum filter banks for different applications is a popular research subject. It has also been shown that principal component filter banks (PCFB) are the optimum filter bank for many application. Existing methods to design FIR PCFBs are based on designing energy compaction filters. In this work we concentrate on designing FIR PCFB with the same frequency response as the ideal one. The presented approach results in filter banks with a very good approximation of ideal PCFB, as verified by simulations. © 2005 IEEE
A Heart-On-A-Chip Platform Containing Channeled Hydrogel for Drug Testing
, M.Sc. Thesis Sharif University of Technology ; Mashayekhan, Shohreh (Supervisor)
Abstract
Cardiovascular diseases are one of the leading causes of death worldwide. Despite significant advances in therapeutic interventions for these diseases, the pathophysiology remains incompletely understood. Challenges in drug evaluation include the lack of appropriate clinical trials, such as conventional 2D cell cultures and animal studies, as well as the absence of model systems that can provide complex and patient-specific cardiac functions for diagnosis. Organ-on-a-chip devices have the potential to mimic the body's response to treatments by utilizing microscale cell culture fluid connections and creating realistic models of human organs of interest. Our objective is to develop a...