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hamidzadeh--z
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Investigation of the Adequacy of Continuity Plates in Cruciform Steel Columns
, M.Sc. Thesis Sharif University of Technology ; Maleki, Shervin (Supervisor)
Abstract
It is very common to use moment frame system in earthquake-prone areas in the two main directions of buildings. This system is very popular among architects due to the creation of unobstructed openings between the columns and the possibility of using openings in them.The column is one of the main components in the design of orthogonal moment frame systems and plays an important role in the performance of this system. The columns that are in the two main directions of the intersection of two moment frame systems, due to the existence of the 30-100 rule in seismic design regulations, must be able to withstand 100% of the design earthquake force in one direction and 30% of the same force in the...
Investigating the Effect of Reinforced Concrete Wall Positioning, with Irregular Plans
, M.Sc. Thesis Sharif University of Technology ; Mofid, Masoud (Supervisor)
Abstract
Previously, numerous studies were carried out on the shear walls and important information are available in various fields, including wall design with various sections, wall design in areas with high seismicity risk, issues related to the reinforcement of boundary element and etc. In the design codes of reinforced concrete structures in the field of seismic design, some criteria for reinforcement of boundary element in the walls were conducted, but these codes do not answer to designers to arrange the wall with or without eccentricity with respect to column or the effect of separation of wall from the column. Due to the fact that we have a powerful software such as ETABS, design of shear...
A New Hierarchal and Scalable Architecture for Performance Enhancement of Large Scale Underwater Sensor Networks
, M.Sc. Thesis Sharif University of Technology ; Movaghar, Ali (Supervisor)
Abstract
Underwater Sensor Network (UWSN) is new branch of Wireless Sensor Network (WSN). UWSNs are considerably different from ground base or terrestrial sensor networks in many aspects. These new features bring many challenges to the network architecture or protocol design of UWSNs. This kind of sensor networks has been proposed to detection, monitoring, protecting the oceans as oceanographic data collector, pollution monitoring, offshore exploration, disaster prevention, assisted navigation and tactical surveillance applications. The different characteristics of UWSN and trade off between UWSN and WSN have been discussed in many researches. Here we aim to propose a new architecture for very large...
Development of a multi-objective decision-making model to recover flare gases in a multi flare gases zone
, Article Energy ; Volume 203 , 2020 ; Sattari, S ; Soltanieh, M ; Vatani, A ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
In this paper, a systematic investigation and modeling of all available technologies (such as NGL, injection in pipelines, LNG, GTL, NGH, and CNG plants, EOR, electricity production by thermal power plants, and water generation by MED technologies) for flare gas recovery has been developed. An optimal combination of the technologies has been proposed for flare gas recovery of five oil wells in the south of Iran with different specifications as case studies. The optimal combinations of all the technologies have been investigated with minimizing the payback period of capital costs (economical) and maximizing CO2 pollutant reduction (environmental) objective functions by using the genetic...
Technical and Economical Feasibility Study of Applying Heat Pump Systems to Provide Utilities for Oil & Gas Industries
, M.Sc. Thesis Sharif University of Technology ; Sattari, Sorena (Supervisor) ; Amidpour, Majid (Supervisor)
Abstract
Distillation is the most applied unit in the separation processess of the oil and gas industries. Because the distillation process requires energy in the form of the utilities, integration of heat pump systems in the distillation process as an application of these systems is considered in this research. A new and effective methodology of proper integrating of heat pump and distillation columns has been proposed by collecting thermodynamic and thermoeconomic tools. Then, this procedure has been applied on the ethane recovery and NGL fractionation units of 4 & 5 phases of the south pars field. The exergy analysis of the distillation columns is the first step of this methodology as the...
Numerical Modeling of Propagation of Sound Waves in an Inhomogeneous and Moving Medium of the Atmospheric Troposphere Layer
, M.Sc. Thesis Sharif University of Technology ; Taeibi Rahni, Mohammad (Supervisor) ; Massah, Hamid Reza (Co-Advisor)
Abstract
Troposphere layer includes complex flows which their effects in acoustic sensors are indicated as acoustic wave noise.It is essential to analyze these complex flows to recognize how to reduce the noise. In this thesis we have perused and modeled the sound wave propagation in troposphere layer.Given data are some thermal and velocity profiles of atmospheric flowsthe assumptions are: 1- gravity waves are negligible, 2- air density depends only on altitude, 3- sound waves parabolic equation assumptions are applied. Our goal Is to find the sound pressure level originated from a sound source in troposphere layer.This thesis emphasizes on analysis, recognition and modeling of the problem. Main...
Down from the pedestal: Revisiting the exploit of literature in EFL language classes
, Article International Journal of Applied Linguistics and English Literature ; Volume 4, Issue 2 , 2015 , Pages 158-168 ; 22003592 (ISSN) ; Lari, Z ; Mosalli, Z ; Sharif University of Technology
Australian International Academic Centre PTY LTD
2015
Abstract
According to Arthur (2006, p. 200), “Through the use of literature, a language learning experience might become at the same time a source of immediate pleasure and satisfaction for the student. This possibility makes literature an appealing teaching device for ESL teachers”. However, numerous factors may contribute to the teachers’ lack of interest in using literary texts as a teaching tool. This study was an attempt to investigate Iranian EFL teachers’ attitude toward using literature in language classes and their perception toward the probable reasons of some teachers’ lack of interest in doing so. Altogether forty-four language teachers (19 females and 25 males, with a mean age of 26)...
Inclusion of carbon nanotubes in a hydroxyapatite sol-gel matrix
, Article Ceramics International ; Volume 35, Issue 7 , 2009 , Pages 2987-2991 ; 02728842 (ISSN) ; Nemati, Z. A ; Sadeghian, Z ; Sharif University of Technology
2009
Abstract
In this study, the inclusion of multi-walled carbon nanotubes as the second phase in the hydroxyapatite matrix, in order to improve the mechanical strength, has been performed via the sol-gel process. The stability of carbon nanotube sol with the changes of pH and dispersant values (sodium dodecyl sulfate) was evaluated by zeta potential analysis. The results indicated that synthesis of hydroxyapatite particles in the presence of the carbon nanotubes had the best result in homogenization of the carbon nanotube dispersion and faster crystallization of hydroxyapatite. The crystallization of hydroxyapatite phase was investigated with differential scanning calorimetry (DSC) and X-ray diffraction...
Fourier optics approach in evaluation of the diffraction and defocus aberration in three-dimensional integral imaging
, Article Computational Modelling of Objects Represented in Images: Fundamentals, Methods and Applications III - Proceedings of the International Symposium, CompIMAGE 2012 ; 2012 , Pages 81-84 ; 9780415621342 (ISBN) ; Kavehvash, Z ; Mehrany, K ; Sharif University of Technology
CRC
2012
Abstract
The unwanted effects of diffraction and defocus aberration in three-dimensional integral imaging are taken into account by using the Fourier optics approach. The concepts of point spread function and optical transfer function widely in use for conventional two-dimensional imaging are generalized and applied to three-dimensional integral imaging systems. The effects of diffraction and defocus aberration are then studied and the performance of the conventional single lens imaging system is compared against that of the integral imaging
Multi-target sputter deposition of Ni50Ti 50 - XHfx shape memory thin films for high temperature microactuator application
, Article Sensors and Actuators, A: Physical ; Volume 121, Issue 2 , 2005 , Pages 543-548 ; 09244247 (ISSN) ; Cao, Y. Z ; Barber, Z. H ; Sharif University of Technology
2005
Abstract
High temperature shape memory NiTiHf thin films with varying hafnium contents up to 28.7 at.% were fabricated by DC magnetron sputtering using simultaneous sputter deposition from separate elemental targets. The required film composition was achieved by adjusting the power ratio to the targets. The as-deposited films were amorphous; a post deposition annealing was performed at 550 °C to crystallize the films. Two-micron thick films were characterized by energy dispersive spectroscopy in a scanning electron microscope, temperature controlled X-ray diffraction, differential scanning calorimetry, and atomic force microscopy. The results showed that above 10 at.% Hf additions the transformation...
Strong Revenue (Non-)Monotonicity of Single-parameter Auctions
, Article EC 2023 - Proceedings of the 24th ACM Conference on Economics and Computation ; 2023 , Pages 452-471 ; 979-840070104-7 (ISBN) ; Huang, Z ; Majdi, D ; Yan, Z ; Sharif University of Technology
Association for Computing Machinery, Inc
2023
Abstract
Consider Myerson's optimal auction with respect to an inaccurate prior, e.g., estimated from data, which is an underestimation of the true value distribution. Can the auctioneer expect getting at least the optimal revenue w.r.t. the inaccurate prior since the true value distribution is larger? This so-called strong revenue monotonicity is known to be true for single-parameter auctions when the feasible allocations form a matroid. We find that strong revenue monotonicity fails to generalize beyond the matroid setting, and further show that auctions in the matroid setting are the only downward-closed auctions that satisfy strong revenue monotonicity. On the flip side, we recover an approximate...
Subsidy cut and its effect on tehran electricity company: A system dynamics approach
, Article Proceedings of the 2012 - Summer Computer Simulation Conference, SCSC 2012, Part of SummerSim 2012 Multiconference ; Volume 44, Issue 10 , 2012 , Pages 113-120 ; 9781618399847 (ISBN) ; Fard, S. Z
2012
Abstract
In recent years, subsidy payment has been made a main challenge for governments due to growth of population and energy price in global markets. Targeted subsidy plan has been implemented in Iran since last year, and this article discusses its effects on costs and revenues of Tehran Electricity Company as one of the major subdivisions of Iran's electricity industry. In the new system, structural changes have been made in electricity tariffs, so it is not possible to predict the future trends in electricity consumption only based on the past consumptions. In order to model the decision making structure in the recent conditions, a system dynamics method is applied. In addition to modeling the...
Interactions of coinage metal clusters with histidine and their effects on histidine acidity; Theoretical investigation
, Article Organic and Biomolecular Chemistry ; Volume 10, Issue 47 , Oct , 2012 , Pages 9373-9382 ; 14770520 (ISSN) ; Jamshidi, Z ; Tehrani, Z. A ; Fattahi, A ; Sharif University of Technology
2012
Abstract
Understanding the nature of interaction between metal nanoparticles and biomolecules such as amino acids is important in the development and design of biosensors. In this paper, binding of M3 clusters (M = Au, Ag and Cu) with neutral and anionic forms of histidine amino acid was studied using density functional theory (DFT-B3LYP). It was found that the interaction of histidine with M3 clusters is governed by two major bonding factors: (a) the anchoring N-M and O-M bonds and (b) the nonconventional N-H⋯M and O-H⋯M hydrogen bonds. The nature of these chemical bonds has been investigated based on quantum theory of atoms in molecules (QTAIM) and natural bond orbital (NBO) analyses. In the next...
Can anion interaction accelerate transformation of cytosine tautomers? Detailed view form QTAIM analysis
, Article Structural Chemistry ; Volume 23, Issue 6 , 2012 , Pages 1843-1855 ; 10400400 (ISSN) ; Tehrani, Z. A ; Fattahi, A ; Jamshidi, Z ; Sharif University of Technology
2012
Abstract
The relative stabilities and noncovalent interactions of the six low-lying energy tautomers of cytosine nucleobase with some biological anions (such as F-, Cl-, and CN-) have been investigated in gas phase by density functional theory (DFT) method in conjunction with 6-311++G (d,p) atomic basis set. Furthermore, to systematically investigate all possible tautomerisms from cytosine induced by proton transfer, we describe a study of structural tautomer interconversion in the gas phase and in a continuum solvent using DFT calculation. We carried out geometrical optimizations with the integral equation formalism of polarizable continuum (IEF-PCM) model to account for the solvent effect, and the...
Interactions of glutathione tripeptide with gold cluster: Influence of intramolecular hydrogen bond on complexation behavior
, Article Journal of Physical Chemistry A ; Volume 116, Issue 17 , 2012 , Pages 4338-4347 ; 10895639 (ISSN) ; Jamshidi, Z ; Javan, M. J ; Fattahi, A ; Sharif University of Technology
2012
Abstract
Understanding the nature of the interaction between metal nanoparticles and biomolecules has been important in the development and design of sensors. In this paper, structural, electronic, and bonding properties of the neutral and anionic forms of glutathione tripeptide (GSH) complexes with a Au 3 cluster were studied using the DFT-B3LYP with 6-31+G**-LANL2DZ mixed basis set. Binding of glutathione with the gold cluster is governed by two different kinds of interactions: Auâ€"X (X = N, O, and S) anchoring bond and Au··•·•H-X nonconventional hydrogen bonding. The influence of the intramolecular hydrogen bonding of glutathione on the interaction of this peptide with the gold cluster has been...
Implementing distance line protection schemes among IEC61850-enabled substations
, Article Proceedings of the IEEE Power Engineering Society Transmission and Distribution Conference ; April , 2014 , Page(s): 1 - 5 ; ISSN: 21608555 ; ISBN: 9781479936557 ; Darabi, Z ; Vakilian, M
2014
Abstract
As digital technology has developed, relays have evolved from simple electro-mechanical devices into robust microprocessor-embedded intelligent electronic devices (IEDs). Distance protection, one of the most important and sophisticated forms of substation protection, quickly and selectively detects and clears phase faults in sub-transmission and transmission lines. The installation of a substation automation system (SAS) involves implementing control, monitoring, and protection logic by programming the IEDs and providing an appropriate communication network. IEC61850 has gradually satisfied the need for a standard communication protocol so that IEDs from different manufacturers can...
Efficient diastereo- and enantioselective synthesis of α,β-disubstituted γ-phosphono sulfonates
, Article Tetrahedron Asymmetry ; Volume 20, Issue 21 , 2009 , Pages 2429-2431 ; 09574166 (ISSN) ; Mirjafary, Z ; Saeidian, H
2009
Abstract
The first asymmetric synthesis of α,β-disubstituted γ-phosphono sulfonates is reported. The key step is the Michael addition of a lithiated enantiopure sulfonate bearing an inexpensive chiral sugar auxiliary to α,β-unsaturated phosphonates in good diastereoselectivities. After chromatographic purification, the cleavage of the chiral sugar auxiliary proceeds without any epimerization or racemization to form the corresponding isopropyl sulfonate in very good overall yield (75%) and excellent diastereomeric and enantiomeric excess (de, ee ≥ 95%). © 2009 Elsevier Ltd. All rights reserved
High-performance UV‐Vis-NIR photodetectors based on plasmonic effect in Au nanoparticles/ZnO nanofibers
, Article Applied Surface Science ; Volume 483 , 2019 , Pages 1110-1117 ; 01694332 (ISSN) ; Arab Bafrani, H ; Naseri, A ; Moshfegh, A. Z ; Sharif University of Technology
Elsevier B.V
2019
Abstract
In this study, UV‐Vis-NIR photodetectors based on decorated ZnO nanofibers (NFs) with optimized coverage of Au nanoparticles (NPs) fabricated via combined simple electrospinning and sputtering techniques are introduced. The effect of different coverages of Au NPs resulted from different Au nominal layer thicknesses on the morphology and optical properties of the ZnO fibers are investigated through various characterization methods. It is discovered that 4 nm Au nominal thickness provides the highest UV on/off ratio (~460), responsivity (~332 A/W), detectivity (~2.93×10 11 Jones) as well as faster rise and decay times as compared to pure ZnO nanofibers. A broad spectral response from UV to NIR...
Engineering quantum Hall phases in a synthetic bilayer graphene system
, Article Physical Review B ; Volume 102, Issue 8 , 2020 ; Grass, T ; Vaezi, A ; Liu, Z ; Hafezi, M ; Sharif University of Technology
American Physical Society
2020
Abstract
Synthetic quantum Hall bilayer (SQHB), realized by optically driven monolayer graphene in the quantum Hall regime, provides a flexible platform for engineering quantum Hall phases as discussed in Ghazaryan et al. [Phys. Rev. Lett. 119, 247403 (2017)PRLTAO0031-900710.1103/PhysRevLett.119.247403]. The coherent driving which couples two Landau levels mimics an effective tunneling between synthetic layers. The tunneling strength, the effective Zeeman coupling, and two-body interaction matrix elements are tunable by varying the driving frequency and the driving strength. Using infinite density matrix renormalization group techniques combined with exact diagonalization, we show that the system...
Effect of Ni, Pd and Ni-Pd nano-islands on morphology and structure of multi-wall carbon nanotubes
, Article Applied Surface Science ; Volume 253, Issue 20 , 2007 , Pages 8458-8462 ; 01694332 (ISSN) ; Mortazavi, Z ; Akhavan, O ; Moshfegh, A. Z ; Lahooti, Sh ; Sharif University of Technology
Elsevier
2007
Abstract
In this research, the effect of Ni, Pd and Ni-Pd catalysts have studied on morphology and structure of synthesized multi-wall carbon nanotubes (MWCNTs). Initially, thin films of Ni (with two thicknesses of 10 and 20 nm), Pd/Ni (5/10 nm) and Pd (10 nm) were deposited as catalysts on SiO 2 (60 nm)/Si(1 0 0) substrates, using dc magnetron sputtering technique. The deposited films were annealed at 900 °C in ammonia environment for 45 min, in order to obtain nano-structured catalyst on the surface. Using scanning electron microscopy (SEM), the average size of Ni nano-islands (synthesized by the 10 and 20 nm Ni films), Pd and Ni-Pd nano-islands were measured about 55, 110, 45 and 50 nm,...