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Nano Structure TiO2 Films by Hybrid PEO-Hydrothermal Method for Dye Sensitised Solar Cell Applications
, M.Sc. Thesis Sharif University of Technology ; Faghihi-Sani, Mohammad Ali (Supervisor) ; Mohammadpour, R (Co-Advisor)
Abstract
This thesis demonstrate a new hybrid Plasma Electrolytic Oxidation (PEO)-Hydrothermal method to produce a nano-structured TiO2 layer over a titanium substrate. Microstructural characterization was carried out by using a FE-SEM to explore nano scale structural changes due to hydrothermal treatment. More over EDS was used to analyse elements of the coating. The FE-SEM images confirmed formation of a 3D network consisting “nano flakes+nano fibers”after 6 or 12 hours and a ”sea urchin like nanostructure+nano fibers” after 24 hour. To improve the performance of nano-structured photoelectrodes, different electrolytes were studied to achieve maximum amount of anatase phase. the best results was...
On the Flutter of Swept Taper Wing in Subsonic Compressible Flow Considering Effect of Fuel Sloshing in External Stores
, M.Sc. Thesis Sharif University of Technology ; Dehghani Firoozabadi, R (Supervisor)
Abstract
In the present work, the aeroelastic stability analysis for the swept taper wing and external fuel tank combination system in subsonic compressible flow are represented. The wing structure is modeled by using the Euler-Bernoulli beam theory. Fuel sloshing is modeled by using an equivalent mechanical mass-spring-damper model. Modal analysis technique is used to drive the structural equations of motion of the system. Aeorodynamic of wing is modeled by using index aerodynamic that has been dived by Marzocca and a slender body aerodynamic theory for the external fuel tank are used. For stability analysis, k-method redrived for a case that structural damping there is. The effects of the external...
Reliability Centered Maintenance (RCM) Implementation in Power Transmission Systems
, M.Sc. Thesis Sharif University of Technology ; Fotuhi-Firuzabad, Mahmud (Supervisor)
Abstract
The current restructuring trend in power industry emplaces the owners and managers under a great pressure to not only reduce the associated investment costs, but also reasonably cut the operation and maintenance expenses as much as possible, while keeping both the power quality and reliability requirements met. Reliability-Centered Maintenance (RCM) has been proved to be in response to this dilemma in power systems since it has been yet successfully applied in various engineering contexts worldwide. This process is more challenging when it comes to the power transmission systems because of its bulkiness and complex structure. On the other hand, market involvement and its intricate behavior...
Design a Comprehensive Risk Management Framework for Electricity Markets
, Ph.D. Dissertation Sharif University of Technology ; Fotuhi Firuzabad, Mahmud (Supervisor)
Abstract
The penetration of variable energy resources together with the utilization of price sensitive loads have intensified supply and demand uncertainties in power systems. Accordingly, system operators and market participants are now seeking for new ways of managing risks within the power system. In this thesis, the risk management is studied from the viewpoints of market participants, transactive market operators and wholesale market operators. In this regard, the optimal bidding strategy of a market participant who participate in wholesale or transactive electricity markets is studied in chapter 3. To reach this goal, behaviors of both risk-neutral and risk-averse agents are modeled taking into...
Electronic commerce 2018 : a managerial and social networks perspective
, Book ; Outland, Jonathan ; King, David R ; Lee, Jae Kyu ; Liang, Ting-Peng ; Turban, Deborrah C
Springer International Publishing AG
2018
Disability and vocational rehabilitation in rural settings : challenges to service delivery
, Book ; Harley, Debra A ; Ysasi, Noel A ; Bishop, Malachy L ; Fleming, Allison R
Springer International Publishing AG
2018
Homoleptic tetraazaphenanthrene-based copper(I) complexes: Synthesis, spectroscopic characterization, crystal structures and computational studies
, Article Inorganica Chimica Acta ; Vol. 423, issue. PA , 2014 , pp. 348-357 ; ISSN :0020-1693 ; Scholz, M ; Raithby, P. R ; Techert, S ; Sharif University of Technology
2014
Abstract
Three new Cu(I) complexes containing bidentate N^N donor ligands with the general formula [Cu(N^N)2][PF6] (N^N = 2,3-diphenyl-6,7-di-p-tolyl-1,4,5,8-tetraazaphenanthrene (L1), 2,3-diphenyl-6,7-di(2-thienyl)-1,4,5,8-tetraazaphenanthrene (L2), and 2,3-diphenyl-6,7-di-p-fluorophenyl-1,4,5,8-tetraazaphenanthrene (L3), were prepared by the reaction of [Cu(CH3CN)4][PF6] with two equivalents of the N^N ligand. Single-crystal X-ray diffraction analysis confirmed that in each complex the metal displays a distorted tetrahedral geometry surrounded by the four N atoms of the two sterically hindered substituted tetraazaphenanthrene (TAP) ligands. Density functional theory (DFT) and time-dependent density...
Electromechanical resonators based on electrospun ZnO nanofibers
, Article Journal of Micro/ Nanolithography, MEMS, and MOEMS ; Vol. 13,Issue. 4 , 2014 ; ISSN: 19325150 ; Mohammadi, S ; Zad, A. I ; Sarvari, R ; Shariatpanahi, S. P ; Sharif University of Technology
2014
Abstract
We present fabrication, characterization, and experimental results describing electrical actuation and readout of the mechanical vibratory response of electrospun ZnO nanofibers. For a fiber with an approximate radius of 200 nm and a length of 70 ìm, a resonance frequency around 3.62 MHz with a quality factor (Q) of about 235 in air at ambient conditions is observed. It is shown that the measured frequency of the resonance is consistent with results from finite element simulations. Also, the measurements were performed in an enclosed chamber with controlled levels of ethanol vapor. The adsorption of ethanol causes a shift in the resonance frequency of the fibers, which can be related to the...
Patchwise joint sparse tracking with occlusion detection
, Article IEEE Transactions on Image Processing ; Vol. 23, Issue. 10 , 2014 , Pages. 4496-4510 ; ISSN: 10577149 ; Rabiee, H. R ; Soltani-Farani, A ; Khajenezhad, A ; Sharif University of Technology
2014
Abstract
This paper presents a robust tracking approach to handle challenges such as occlusion and appearance change. Here, the target is partitioned into a number of patches. Then, the appearance of each patch is modeled using a dictionary composed of corresponding target patches in previous frames. In each frame, the target is found among a set of candidates generated by a particle filter, via a likelihood measure that is shown to be proportional to the sum of patch-reconstruction errors of each candidate. Since the target's appearance often changes slowly in a video sequence, it is assumed that the target in the current frame and the best candidates of a small number of previous frames, belong to...
Low-data complexity biclique cryptanalysis of block ciphers with application to piccolo and HIGHT
, Article IEEE Transactions on Information Forensics and Security ; Vol. 9, Issue. 10 , 2005 , Pages 1641-1652 ; Ahmadian, Z ; Mohajeri, J ; Aref, M. R ; Sharif University of Technology
2005
Abstract
In this paper, we present a framework for biclique cryptanalysis of block ciphers which extremely requires a low amount of data. To that end, we enjoy a new representation of biclique attack based on a new concept of cutset that describes our attack more clearly. Then, an algorithm for choosing two differential characteristics is presented to simultaneously minimize the data complexity and control the computational complexity. Then, we characterize those block ciphers that are vulnerable to this technique and among them, we apply this attack on lightweight block ciphers Piccolo-80, Piccolo-128, and HIGHT. The data complexity of these attacks is only 16-plaintext-ciphertext pairs, which is...
Effect of nano-particles and aminosilane interaction on the performances of cement-based composites: An experimental study
, Article Construction and Building Materials ; Vol. 66 , 2014 , Pages 113-124 ; ISSN: 09500618 ; Hosseinpourpia, R ; Pajum, A ; Khodavirdi, M. M ; Izadi, H ; Vaezi, A ; Sharif University of Technology
2014
Abstract
The aim of the present study was to experimentally investigate the interaction between a low replacement ratio of different nano-particles (SiO2, Al2O3, clay, and CaCO3) and aminosilane in the matrices of cement paste and mortar. Results showed that the optimum content of aminosilane for improving the 28-day compressive strength of cement mortar was 0.75% (by weight of the total binder). The utilization of nano-SiO2 and nano-clay particles improved the strengths of the cement mortar containing hybrid systems of nano-particles/aminosilane at early (7 days) and middle curing ages (28 and 91 days). The 28-day compressive strength enhancement of cement mortar with hybrid systems of nano-SiO...
Study the effect of architectural modification on fracture behavior of Al-DRA composite
, Article Mechanics of Advanced Materials and Structures ; Vol. 21, issue. 8 , 2014 , Pages 662-668 ; ISSN: 15376494 ; Khalili, S ; Bagheri, R ; Simchi, A ; Sharif University of Technology
2014
Abstract
An architectural modification method was utilized to improve fracture toughness of discontinuously reinforced aluminum (DRA) composites. Al-DRA composites having a structure similar to that of reinforced concrete were fabricated. The number of reinforcing DRA rods within Al matrix and volume fraction of SiC particles in DRA were altered to evaluate their effect on fracture behavior of these materials. It was found that architectural modification does not have any destructive influence on elastic modulus and yield strength of the composite. Moreover, the success of this method on toughness improvement strongly depends on the occurrence of debonding between Al and DRA regions upon loading
Statistical anisotropies in gravitational waves in solid inflation
, Article Journal of Cosmology and Astroparticle Physics ; Vol. 2014,Issue. 9 , 2014 ; ISSN: 14054179 ; Emami, R ; Firouzjahi, H ; Wang, Y ; Sharif University of Technology
2014
Abstract
Solid inflation can support a long period of anisotropic inflation. We calculate the statistical anisotropies in the scalar and tensor power spectra and their cross-correlation in anisotropic solid inflation. The tensor-scalar cross-correlation can either be positive or negative, which impacts the statistical anisotropies of the TT and TB spectra in CMB map more significantly compared with the tensor self-correlation. The tensor power spectrum contains potentially comparable contributions from quadrupole and octopole angular patterns, which is different from the power spectra of scalar, the cross-correlation or the scalar bispectrum, where the quadrupole type statistical anisotropy dominates...
Cell-imprinted substrates act as an artificial niche for skin regeneration
, Article ACS Applied Materials and Interfaces ; Vol. 6, Issue. 15 , 2014 , Pages 13280-13292 ; ISSN: 19448244 ; Bonakdar, S ; Taghinejad, H ; Satarifard, V ; Heidari, M ; Majidi, M ; Sharifi, S ; Peirovi, A ; Saffar, S ; Taghinejad, M ; Abdolahad, M ; Mohajerzadeh, S ; Shokrgozar, M. A ; Rezayat, S. M ; Ejtehadi M. R ; Dalby, M. J ; Mahmoudi, M ; Sharif University of Technology
2014
Abstract
Bioinspired materials can mimic the stem cell environment and modulate stem cell differentiation and proliferation. In this study, biomimetic micro/nanoenvironments were fabricated by cell-imprinted substrates based on mature human keratinocyte morphological templates. The data obtained from atomic force microscopy and field emission scanning electron microscopy revealed that the keratinocyte-cell-imprinted poly(dimethylsiloxane) casting procedure could imitate the surface morphology of the plasma membrane, ranging from the nanoscale to the macroscale, which may provide the required topographical cell fingerprints to induce differentiation. Gene expression levels of the genes analyzed...
Experimental and modelling investigations of asphaltene precipitation during pressure depletion and gas injection operations
, Article Petroleum Science and Technology ; Vol. 32, issue. 15 , August , 2014 , pp. 1868-1875 ; ISSN: 10916466 ; Alizadeh, A ; Afshari, S ; Kharrat, R ; Ghazanfari, M ; Sharif University of Technology
2014
Abstract
Asphaltene precipitation problems manifest themselves in different stages of oil reservoirs production. Experimental and modeling investigations are, therefore, employed as promising tools to assist in predictions of asphaltene precipitation problems and selection of proper production facilities. This study concerns experimental and modeling investigations of asphaltene precipitation during natural production and gas injection operations for a heavy Iranian crude oil at reservoir conditions. First, with design and performance of high pressure-high temperature experiments, asphaltene precipitation behavior is comprehensively investigated; the effects of pressure and temperature are fully...
Physical properties of the WASP-67 planetary system from multi-colour photometry
, Article Astronomy and Astrophysics ; Vol. 568 , August , 2014 ; ISSN: 00046361 ; Southworth, J ; Ciceri, S ; Calchi Novati, S ; Dominik, M ; Henning, Th ; Jorgensen, U. G ; Korhonen, H ; Nikolov, N ; Alsubai, K. A ; Bozza, V ; Bramich, D. M ; D'Ago, G ; Figuera Jaimes, R ; Galianni, P ; Gu, S. H ; Harpsoe, K ; Hinse, T. C ; Hundertmark, M ; Juncher, D ; Kains, N ; Popovas, A ; Rabus, M ; Rahvar, S ; Skottfelt, J ; Snodgrass, C ; Street, R ; Surdej, J ; Tsapras, Y ; Vilela, C ; Wang, X. B ; Wertz, O ; Sharif University of Technology
2014
Abstract
Context. The extrasolar planet WASP-67 b is the first hot Jupiter definitively known to undergo only partial eclipses. The lack of the second and third contact points in this planetary system makes it difficult to obtain accurate measurements of its physical parameters
Disease diagnosis with a hybrid method SVR using NSGA-II
, Article Neurocomputing ; Vol. 136 , 2014 , pp. 14-29 ; Habibi, J ; Alizadehsani, R ; Sharif University of Technology
2014
Abstract
Early diagnosis of any disease at a lower cost is preferable. Automatic medical diagnosis classification tools reduce financial burden on health care systems. In medical diagnosis, patterns consist of observable symptoms and the results of diagnostic tests, which have various associated costs and risks. In this paper, we have experimented and suggested an automated pattern classification method for classifying four diseases into two classes. In the literature on machine learning or data mining, regression and classification problems are typically viewed as two distinct problems differentiated by continuous or categorical dependent variables. There are endeavors to use regression methods to...
Studies of dijet transverse momentum balance and pseudorapidity distributions in pPb collisions at √sNN = 5.02 TeV
, Article European Physical Journal C ; Vol. 74, issue. 7 , July , 2014 ; ISSN: 14346044 ; Chatrchyan, S ; Khachatryan, V ; Sirunyan, A. M ; Tumasyan, A ; Adam, W ; Bergauer, T ; Dragicevic, M ; Ero, J ; Fabjan, C ; Friedl, M ; Fruhwirth, R ; Ghete, V. M ; Hartl, C ; Hrubec, J ; Hormann, N ; Jeitler, M ; Kiesenhofer, W ; Knunz, V ; Krammer, M ; Kratschmer, I ; Liko, D ; Mikulec, I ; Rabady, D ; Rahbaran, B ; Rohringer, H ; Schofbeck, R ; Strauss, J ; Taurok, A ; Treberer-Treberspurg, W ; Waltenberger, W ; Wulz, C. E ; Mossolov, V ; Shumeiko, N ; Suarez Gonzalez, J ; Alderweireldt, S ; Bansal, M ; Bansal, S ; Cornelis, T ; De Wolf, E. A ; Janssen, X ; Knutsson, A ; Luyckx, S ; Mucibello, L ; Ochesanu, S ; Roland, B ; Rougny, R ; Van Haevermaet, H ; Van Mechelen, P ; Van Remortel, N ; Sharif University of Technology
2014
Abstract
Dijet production has been measured in pPb collisions at a nucleon–nucleon centre-of-mass energy of 5.02 TeV. A data sample corresponding to an integrated luminosity of 35 nb−1 was collected using the Compact Muon Solenoid detector at the Large Hadron Collider. The dijet transverse momentum balance, azimuthal angle correlations, and pseudorapidity distributions are studied as a function of the transverse energy in the forward calorimeters (E4<|η|<5.2 T). For pPb collisions, the dijet transverse momentum ratio and the width of the distribution of dijet azimuthal angle difference are comparable to the same quantities obtained from a simulated pp reference and insensitive to E4<|η|<5.2 T. In...
Search for excited quarks in the γ + jet final state in proton-proton collisions at √s=8TeV
, Article Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics ; Vol. 738, issue , 2014 , pp. 274-293 ; Sirunyan, A. M ; Tumasyan, A ; Adam, W ; Bergauer, T ; Dragicevic, M ; Ero, J ; Fabjan, C ; Friedl, M ; Fruhwirth, R ; Ghete, V. M ; Hartl, C ; Hormann, N ; Hrubec, J ; Jeitler, M ; Kiesenhofer, W ; Knunz, V ; Krammer, M ; Kratschmer, I ; Liko, D ; Mikulec, I ; Rabady, D ; Rahbaran, B ; Rohringer, H ; Schofbeck, R ; Strauss, J ; Taurok, A ; Treberer Treberspurg, W ; Waltenberger, W ; Wulz, C. E ; Mossolov, V ; Shumeiko, N ; Suarez Gonzalez, J ; Alderweireldt, S ; Bansal, M ; Bansal, S ; Cornelis, T ; De Wolf, E. A ; Janssen, X ; Knutsson, A ; Luyckx, S ; Ochesanu, S ; Roland, B ; Rougny, R ; Van De Klundert, M ; Van Haevermaet, H ; Van Mechelen, P ; Van Remortel, N ; Van Spilbeeck, A ; Blekman, F ; Sharif University of Technology
2014
Abstract
A search for excited quarks decaying into the γ + jet final state is presented. The analysis is based on data corresponding to an integrated luminosity of 19.7 fb-1 collected by the CMS experiment in proton-proton collisions at √s=8TeV at the LHC. Events with photons and jets with high transverse momenta are selected and the γ + jet invariant mass distribution is studied to search for a resonance peak. The 95% confidence level upper limits on the product of cross section and branching fraction are evaluated as a function of the excited quark mass. Limits on excited quarks are presented as a function of their mass and coupling strength; masses below 3.5 TeV are excluded at 95% confidence...