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Electrochemical Deposition of Composite Coatings of Nickel - Silicon Carbide Under Pulsed Current Using a Rotating Disk Electrode
, M.Sc. Thesis Sharif University of Technology ; Ghorbani, Mohammad (Supervisor)
Abstract
Ni-SiC composite coatings are widely used in industry (equipment high wear resistance coatings, corrosion resistant coatings, ship and boiler coatings, . . . ). Its unique properties in high wear resistance, corrosion resistance and tribological properties, researchers tend to investigate this coating. This study covers Ni-SiC composite coating under pulsed current using a rotating disk electrode to achieve optimal conditions in synthsis process, increaseing hardness and resistance to corrosion in coatings.waats' bath established for electrodeposition in this research. Bath parameters, current parameters and hydrodynamic of solution is examined. Changing of current type from direct current...
Alteration of corrosion and nanomechanical properties of pulse electrodeposited Ni/SiC nanocomposite coatings
, Article Journal of Alloys and Compounds ; Vol. 598 , 2014 , Pages 236-242 ; ISSN: 09258388 ; Ghorbani, M ; Sharif University of Technology
2014
Abstract
Nickel/silicon carbide composite electrodeposits were prepared on a rotating disk electrode (RDE), under pulse current condition. The effect of pulse parameters, current density, SiC content in the electrolyte on the codeposition of SiC were studied. Afterwards, the effect of codeposited SiC amount was investigated on electrochemical behavior and nanomechanical properties of coatings. The coatings were analyzed with Scanning Electron Microscopy (SEM), linear polarization, nanoindentation and Atomic Force Microscopy (AFM). The Ni-SiC electrocomposites, prepared at optimum conditions, exhibited improved nanomechanical properties in comparison to pure nickel electrodeposits. With increasing...
Numerical Study on Stress Distribution of SolderJoints Based on Solder Microstructure
, M.Sc. Thesis Sharif University of Technology ; Nourani, Amir (Supervisor)
Abstract
In the past, lead-based solders with homogeneous and isotropic behavior were used in microelectronic packages. But today, due to the environmental concerns of lead, lead-free solders have been developed, which consist of a high weight percentage (more than 90%) of tin. Tin crystal shows significant anisotropic behavior, which leads to an anisotropic joint response in miniature solder joints with a small number of grains. In the first part of this research, using the crystal plasticity model, the anisotropic plastic response of tin grain was extracted from bulk solder stress-strain curve, then it was implemented in Abaqus software using built-in Hill's anisotropic plasticity model to consider...
Automatic Classification of Masses in Mammographic Images using Sparse Representation
, M.Sc. Thesis Sharif University of Technology ; Manzouri, Mohammad Taghi (Supervisor)
Abstract
Computer Aided Diagnosis (CAD) systems are widely used in different medical tasks. Radiology is a branch of medicine which takes advantage of image processing techniques to help radiologists, analyse complicated radiologic images. Among all kind of medical imagingprocedures, utilization of screening mammographyisgetting very popularin detection of breast abnormalities. A typical CAD system for mammogram analysis uses image enhancement and segmentation as pre-processing phase, and feature extraction and classification for detection phase. In this thesis, we have studied different approaches in each level of image processing required in a mammogram mass classification systems, and introduced a...
Multi-Attribute decision making on Inter-Basin Water Transfer projects
, Article Scientia Iranica ; Volume 16, Issue 1 E , 2009 , Pages 73-80 ; 10263098 (ISSN) ; Szidarovszky, F ; Ardakanian, R ; Sharif University of Technology
2009
Abstract
One of the best ways to control water shortages in the central region of Iran is Inter-Basin Water Transfer (IBWT). Efficient decision making on this subject is, however, a real challenge for the water authorities in Iran. These decisions should include multiple attributes, model uncertainty and, also, the optimistic/pessimistic view of the decision makers. The Ordered Weighted Averaging (OWA) operator can be used as an efficient Multi-Attribute Decision Making (MADM) method. This paper will introduce a new method to obtain the order weights of this operator. The new method is based on a combination of fuzzy quantifiers and neat OWA operators. Fuzzy quantifiers are usually applied in soft...
A fuzzy-stochastic OWA model for robust multi-criteria decision making
, Article Fuzzy Optimization and Decision Making ; Volume 7, Issue 1 , 2008 , Pages 1-15 ; 15684539 (ISSN) ; Szidarovszky, F ; Ardakanian, R ; Sharif University of Technology
2008
Abstract
All realistic Multi-Criteria Decision Making (MCDM) problems face various kinds of uncertainty. Since the evaluations of alternatives with respect to the criteria are uncertain they will be assumed to have stochastic nature. To obtain the uncertain optimism degree of the decision maker fuzzy linguistic quantifiers will be used. Then a new approach for fuzzy-stochastic modeling of MCDM problems will be introduced by merging the stochastic and fuzzy approaches into the OWA operator. The results of the new approach, entitled FSOWA, give the expected value and the variance of the combined goodness measure for each alternative. Robust decision depends on the combined goodness measures of...
Sensitivity analysis of the OWA operator
, Article IEEE Transactions on Systems, Man, and Cybernetics, Part B: Cybernetics ; Volume 38, Issue 2 , 2008 , Pages 547-552 ; 10834419 (ISSN) ; Szidarovszky, F ; Ardakanian, R ; Sharif University of Technology
2008
Abstract
The successful design and application of the ordered weighted averaging (OWA) method as a decision-making tool depend on the efficient computation of its order weights. The most popular methods for determining the order weights are the fuzzy linguistic quantifiers approach and the minimal variability method, which give different behavior patterns for the OWA. These two methods will be first analyzed in detail by using sensitivity analysis on the outputs of the OWA with respect to the optimism degree of the decision maker, and then the two methods will be compared. The fuzzy linguistic quantifiers approach gives more information about the behavior of the OWA outputs in comparison to the...
Multi-criteria decision making for integrated urban water management
, Article Water Resources Management ; Volume 22, Issue 8 , 2008 , Pages 1017-1029 ; 09204741 (ISSN) ; Abrishamchi, A ; Ardakanian, R ; Sharif University of Technology
2008
Abstract
The city of Zahedan, in South-eastern Iran, has high population growth, limited local freshwater resources and inadequate water distribution system resulting in water supply failures in recent years. This paper will investigate integration of several demand management measures such as leakage detection on water distribution network, water metering and low volume water fixtures as well as the conjunctive use of surface and groundwater resources of this city. For integration of water management criteria, compromise programming will be used as a multi-objective decision making method. The criteria include minimizing the cost, maximizing water supply and minimizing the social hazards due to the...
Morphological manipulation of solvothermal prepared CdSe nanostructures by controlling the growth rate of nanocrystals as a kinetic parameter
, Article Journal of Electronic Materials ; Volume 41, Issue 11 , 2012 , Pages 3050-3055 ; 03615235 (ISSN) ; Mohammadi, M. R ; Fray, D. J ; Sharif University of Technology
2012
Abstract
The morphological manipulation, structural characterization, and optical properties of different cadmium selenide (CdSe) nanostructures are reported. Two different CdSe nanostructures, i.e., nanorods and nanoparticles, were grown by controlling the concentration of precursors (i.e., cadmium nitrate and selenium dioxide) in ethanolamine solvent. By manipulating the kinetic parameter of the process (i.e., growth rate) under constant growth driving force (i.e., degree of supersaturation), the morphology of CdSe nanostructures can be tailored from nanorods to nanoparticles. The optical properties of CdSe nanostructures were investigated using ultraviolet-visible (UV-vis) spectroscopy. The...
Evaluating the uncertainty of urban flood model using glue approach
, Article Urban Water Journal ; Volume 19, Issue 6 , 2022 , Pages 600-615 ; 1573062X (ISSN) ; Fazloula, R ; Zarghami, M ; Akbarpour, A ; Sharif University of Technology
Taylor and Francis Ltd
2022
Abstract
This study is an attempt to investigate and analyze uncertainty through the Glue method in parts of Tabriz, Iran, using the SWMM urban flood model. In order to quantify the uncertainty, the initial range of input parameters including curve number, impenetrability percentage, penetrability level’s coarseness coefficient, and impenetrability level’s coarseness coefficient are defined and the GLUE algorithm is used to conduct primary sampling operation from parametric space using Latin hypercube sampling method. Considering the simulation results and the observed values of synchronized events, about %20 of the total outputs and generated parameters series have been excluded as acceptable...
A bayesian framework for sparse representation-based 3-d human pose estimation
, Article IEEE Signal Processing Letters ; Vol. 21, issue. 3 , 2014 , pp. 297-300 ; ISSN: 10709908 ; Jourabloo, A ; Zarghami, A ; Kasaei, S ; Sharif University of Technology
2014
Abstract
A Bayesian framework for 3-D human pose estimation from monocular images based on sparse representation (SR) is introduced. Our probabilistic approach aims at simultaneously learning two overcomplete dictionaries (one for the visual input space and the other for the pose space) with a shared sparse representation. Existing SR-based pose estimation approaches only offer a point estimation of the dictionary and the sparse codes. Therefore, they might be unreliable when the number of training examples is small. Our Bayesian framework estimates a posterior distribution for the sparse codes and the dictionaries from labeled training data. Hence, it is robust to overfitting on small-size training...
In vitro bactericidal and drug release properties of vancomycin-amino surface functionalized bioactive glass nanoparticles
, Article Materials Chemistry and Physics ; Volume 241 , 2020 ; Ghorbani, M ; Bagheri, K.P ; Shokrgozar, M. A ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
Bioactive glass has been used clinically in bone repair applications for bone grafting because of its prominent physiochemical and osteogenic properties. Various attempts have been made to enhance bioactive glass efficiency in combination with other biomaterials such as antibiotics and growth factors. In present study, we developed a modification of bioactive glass nanoparticles that insured long term antibacterial effect. Bioactive glass nanoparticles (BGNs) were functionalized with (3-Aminopropyl) triethoxysilane (APTS), then vancomycin (VAN) was immobilized onto BGNs-APTS via EDC/NHS cross-linking process. Another study group namely BGNs-VAN was synthesized as a control group without any...
Estimating Multidimensional Poverty Index for Iran in AF Method and Compuiting its Trend with Income Poverty Index
, M.Sc. Thesis Sharif University of Technology ; Fatemi Ardestani, Farshad (Supervisor) ; Souri, Davood (Co-Supervisor)
Abstract
Because of the importance of the issue of poverty, in this study, we introduce and copute aspects & dimensions of multidimensional poverty index. The object of this thesis is studing the trend of changes in Iranian households’ welfare during the years 2005 through 2015 and recognizing the economic and social poor households’ characteristics. There are two methods that are used to computing MPI (Multidimensional Poverty Index). One of them is standard method that is given unique weight to each dimension, the other one is questionnaire method which is asked poverty experts to set proper weight to each dimension. Knowing how poverty index (income & mpi) changes, can help policy makers to...
Improving bactericidal performance of implant composite coatings by synergism between Melittin and tetracycline
, Article Journal of Materials Science: Materials in Medicine ; Volume 33, Issue 6 , 2022 ; 09574530 (ISSN) ; Ghorbani, M ; Pooshang Bagheri, K ; Shokrgozar, M. A ; Sharif University of Technology
Springer
2022
Abstract
Methicillin resistance Staphylococcus aureus bacteria (MRSA) are serious hazards of bone implants. The present study was aimed to use the potential synergistic effects of Melittin and tetracycline to prevent MRSA associated bone implant infection. Chitosan/bioactive glass nanoparticles/tetracycline composite coatings were deposited on hydrothermally etched titanium substrate. Melittin was then coated on composite coatings by drop casting method. The surfaces were analyzed by FTIR, XRD, and SEM instruments. Tetracycline in coatings revealed multifunctional behaviors include bone regeneration and antibacterial activity. Releasing ALP enzyme from MC3T3 cells increased by tetracycline, so it is...
Experimental Investigation of Bubble Growth on Fluidized Bed Distributor
, M.Sc. Thesis Sharif University of Technology ; Rashtchian, Davood (Supervisor) ; Zarghami, Reza (Supervisor)
Abstract
In this study formation of a single bubble on fluidized bed distributor is investigated. Digital image processing and pressure sensors are used to analyze bubble characteristics. Effects of density and the size of particles on bubble diameter, formation time, separation and passing velocity was studied in different flow rates of nozzle. Bubble diameter when is separated from nozzle was greater for lower density particles which have the same size. The ratio of diameter formation was approximately equal to inverse of densities ratio. Bubble formation time is decreased by increasing the flow rate of nozzle and the formation time is approached to a specified value. In addition, it was observed...
Boron nitride nanotube as an antimicrobial peptide carrier: A theoretical insight
, Article International Journal of Nanomedicine ; Volume 16 , 2021 , Pages 1837-1847 ; 11769114 (ISSN) ; Bagheri, B ; Yousefi, F ; Nasiriasayesh, A ; Mashhadzadeh, A. H ; Zarrintaj, P ; Rabiee, N ; Bagherzadeh, M ; Fierro, V ; Celzard, A ; Saeb, M. R ; Mostafavi, E ; Sharif University of Technology
Dove Medical Press Ltd
2021
Abstract
Introduction: Nanotube-based drug delivery systems have received considerable attention because of their large internal volume to encapsulate the drug and the ability to penetrate tissues, cells, and bacteria. In this regard, understanding the interaction between the drug and the nanotube to evaluate the encapsulation behavior of the drug in the nanotube is of crucial importance. Methods: In this work, the encapsulation process of the cationic antimicrobial peptide named cRW3 in the biocompatible boron nitride nanotube (BNNT) was investigated under the Canonical ensemble (NVT) by molecular dynamics (MD) simulation. Results: The peptide was absorbed into the BNNT by van der Waals (vdW)...
An integrated analysis to predict micro-RNAs targeting both stemness and metastasis in breast cancer stem cells
, Article Journal of Cellular and Molecular Medicine ; Volume 23, Issue 4 , 2019 , Pages 2442-2456 ; 15821838 (ISSN) ; Sharifi Zarchi, A ; Firouzi, J ; Azimi, M ; Zarghami, N ; Alizadeh, E ; Ebrahimi, M ; Sharif University of Technology
Blackwell Publishing Inc
2019
Abstract
Several evidences support the idea that a small population of tumour cells representing self-renewal potential are involved in initiation, maintenance, metastasis, and outcomes of cancer therapy. Elucidation of microRNAs/genes regulatory networks activated in cancer stem cells (CSCs) is necessary for the identification of new targets for cancer therapy. The aim of the present study was to predict the miRNAs pattern, which can target both metastasis and self-renewal pathways using integration of literature and data mining. For this purpose, mammospheres derived from MCF-7, MDA-MB231, and MDA-MB468 were used as breast CSCs model. They had higher migration, invasion, and colony formation...
Bioactive Nanocomposite Coatings Containing Anti-Bacterial Factors with Controlled Release on the Bone Implant
, Ph.D. Dissertation Sharif University of Technology ; Ghorbani, Mohammad (Supervisor) ; Shokrgozar, Mohammad Ali (Supervisor) ; Pooshang Bagheri, Kamran (Co-Supervisor)
Abstract
Aseptic loosening and infection are two major problems of bone implants. Aseptic loosening occurs due to poor cell growth and poor adhesion to the implant surface over time. Bone infection at the implant site occurs mainly by the staphylococcus aureus bacteria. In some cases, infection occurs in the short term and in the early times after implantation, and in some cases, infection occurs in later times. The aim of this study is to synthesize and evaluate antibacterial coatings, while having cell growth-promoting components and cell differentiation to solve bone implant problems simultaneously. Also, the issue of bacterial resistance to antibiotics and their risks in bone implants is another...
Multi-modal distance metric learning: A bayesian non-parametric approach
, Article Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 6 September 2014 through 12 September 2014 ; Volume 8927 , September , 2015 , Pages 63-77 ; 03029743 (ISSN) ; 9783319161983 (ISBN) ; Roostaiyan, S. M ; Zarghami, A ; Baghshah, M. S ; Rother, C ; Agapito, L ; Bronstein, M. M ; Sharif University of Technology
Springer Verlag
2015
Abstract
In many real-world applications (e.g. social media application), data usually consists of diverse input modalities that originates from various heterogeneous sources. Learning a similarity measure for such data is of great importance for vast number of applications such as classification, clustering, retrieval, etc. Defining an appropriate distance metric between data points with multiple modalities is a key challenge that has a great impact on the performance of many multimedia applications. Existing approaches for multi-modal distance metric learning only offer point estimation of the distance matrix and/or latent features, and can therefore be unreliable when the number of training...
NIR emitting platinum pincer complexes based on the N^N^C ligand containing {benz[4,5]imidazo[1,2-a]pyrazin} aromatic system; synthesis, characterization and photophysical study
, Article Inorganica Chimica Acta ; Volume 511 , 2020 ; Hendi, Z ; Zhukovsky, D. D ; Sokolov, V. V ; Jamali, S ; Pavlovskiy, V. V ; Porsev, V. V ; Evarestov, R. A ; Tunik, S. P ; Sharif University of Technology
Elsevier S.A
2020
Abstract
In the present work we obtained a series of NIR luminescent platinum(II) complexes with a pincer N^N^C ligand based on the conjugated {benzoimidazo[1,2-a]pyrazine} system with the [Pt(N^N^C)L]n+ structural motif (L = phosphine, alkynyl or pyridine-type ligands). We have also synthesized two complexes with bidentate phosphines that demonstrate different types of coordination: 1) as chelating ligand (in case of 1,2-bis(diphenylphosphino)benzene), that led to de-coordination of pyridine ring of N^N^C ligand and formation of a [Pt(N^C)dppb]+ complex; 2) as a bridging ligand (in case of bis(diphenylphosphino)methane) between two {Pt(N^N^C)} fragments in a dimeric complex of type...