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pourghazian-esfahani--alireza
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Effect of Oleuropein as Green Inhibitor on Corrosion Protection of Painted Steel
, M.Sc. Thesis Sharif University of Technology ; Ghorbani, Mohammad (Supervisor)
Abstract
The corrosion rate of steel (EN 10130 DC-04) in the presence of oleuropein in aqueous corrosive solutions (of different concentrations in 1M and 0.5M hydrochloric acid and also 3.5% sodium chloride) evaluated and results was shown that oleuropein can protect steel surfaces and it acts as good inhibitor. This means that the observations of linear polarization and weight loss experiments showed inhibitor efficiency more than 97% in acidic corrosive medium and above 74% for aqueous solution of 3.5% sodium chloride. Adding oleuropein at different concentrations (i.e. 300 ppm, 700 ppm, and 1000 ppm) to three different types of polymeric paint structures (nitrocellulose alkyd base, acrylic base,...
Experimental Investigations on Reinforced Concrete Slabs Strengthening by FRP Sheets
, M.Sc. Thesis Sharif University of Technology ; Khaloo, Alireza (Supervisor)
Abstract
A total of four reinforced concrete slabs with dimension of 2200×1000×100 mm strengthened with different layers of GFRP sheets were fabricated and tested. A loading of the slabs was performed using displacement control approach.In addition, nonlinear finite element analysis (NLFEA) using ANSYS package was used to simulate the behavior of the test specimens. After reasonable validation of NLFEA with the experimental test results of companion slabs, NLFEA was expanded to provide a parametric study of sixty two slabs. Forty two numbers of these sixty two slabs were without any opening and were modeled for different type of concrete strength, ratio of length/wide for slabs, type of FRP, number...
Solving a Flexible, Multi-Objective Multi-Depot VRP and IRP Considering 3DP and Sustainability with Several Levels in the Transportation Network
, M.Sc. Thesis Sharif University of Technology ; Haji, Alireza (Supervisor) ; Fatahi Valilai, Omid (Supervisor)
Abstract
A sustainable supply chain requires constant sustainable changes in the design and performance of its steps. The main characteristic of sustainability is the consideration of social, environmental and economic criteria in strategic and operational decisions. Due to the great importance of the sustainability in transportation network, proper planning and careful design for this issue in recent years has been considered and welcomed by relevant researchers. In this research we want to provide an integrated frame work for transportation network design toward sustainability. In this regard, we also use 3D printing technology as our innovation in operations. Our main issue is the Inventory...
A higher index theorem for foliated manifolds with boundary
, Article Bulletin des Sciences Mathematiques ; Volume 136, Issue 2 , 2012 , Pages 201-238 ; 00074497 (ISSN) ; Sharif University of Technology
2012
Abstract
Following Gorokhovsky and Lott and using an extension of the b-pseudodifferential calculus of Melrose, we give a formula for the Chern character of the Dirac index class of a longitudinal Dirac type operators on a foliated manifold with boundary. For this purpose we use the Bismut local index formula in the context of noncommutative geometry. This paper uses heavily the methods and technical results developed by E. Leichtnam and P. Piazza
On vanishing of low-degree higher Â-genera
, Article Differential Geometry and its Application ; Volume 43 , 2015 , Pages 56-59 ; 09262245 (ISSN) ; Sharif University of Technology
2015
Abstract
In this short note we apply methods introduced by B. Hanke and T. Schick to prove the vanishing of (low degree) higher Â-genera for spin manifolds admitting a positive scalar curvature metric. Our aim is to provide a short proof for this beautiful result
MiR-9-5p and miR-106a-5p dysregulated in CD4+ T-cells of multiple sclerosis patients and targeted essential factors of T helper17/regulatory T-cells differentiation
, Article Iranian Journal of Basic Medical Sciences ; Volume 21, Issue 3 , March , 2018 , Pages 277-283 ; 20083866 (ISSN) ; Hosseini, A ; Ghaedi, K ; Kiani Esfahani, A ; Tanhaei, S ; Shiralian Esfahani, H ; Rahnamaee, S. Y ; Mowla, S. J ; Nasr Esfahani, M. H ; Sharif University of Technology
Mashhad University of Medical Sciences
2018
Abstract
Objective(s): Multiple sclerosis (MS) is considered as a chronic type of an inflammatory disease characterized by loss of myelin of CNS. Recent evidence indicates that Interleukin 17 (IL-17)-producing T helper cells (Th17 cells) population are increased and regulatory T cells (Treg cells) are decreased in MS. Despite extensive research in understanding the mechanism of Th17 and Treg differentiation, the role of microRNAs in MS is not completely understood. Thereby, as a step closer, we analyzed the expression profile of miR-9-5p and miR-106a-5p, and protein level of retinoic acid receptor (RAR)-related orphan receptor C (RORC; Th17 master transcription factor) as direct target of miR-106a-5p...
Robust Design Optimization for Fatigue Life with Geometric and Material Uncertainties of Mechanical Parts Under Random Loading Based on Maximizing Fatigue Life and Minimizing Uncertainty in Fatigue Llife Prediction
, M.Sc. Thesis Sharif University of Technology ; Khodaygan, Saeed (Supervisor)
Abstract
Fatigue life prediction of a mechanical part is one of issues which a group of engineers are engaged with it and always they try to design the parts with the maximum of lifetime. Although many researches have been done in this field but yet we can see that predicted life are different from that happens in the reality because there are some uncertainties in the phenomena. Our effort in this project is creating an algorithm design so that the parts are designed by it, have the maximum fatigue life and the minimum uncertainty in prediction. In this project we have considered geometrical, material and random loading uncertainties as error resources. Older methods those are presented in this...
Efficient recyclable catalytic system for deoxygenation of sulfoxides: Catalysis of ionic liquid-molybdenum complexes in ionic liquid solution
, Article New Journal of Chemistry ; Volume 36, Issue 4 , Dec , 2012 , Pages 971-976 ; 11440546 (ISSN) ; Ghazali Esfahani, S ; Sharif University of Technology
2012
Abstract
Three newly synthesized room temperature ionic liquids containing molybdate anion, [DMIm][MoO 2(NCS) 4], [RPy][MoO 2(NCS) 4] (R = butyl or decyl), and previously reported [BMIm][MoO 2(NCS) 4] were used as catalysts for the reduction of sulfoxides. For facilitating the recyclability of the catalysts, the ionic liquids [RMIm][PF 6] and [RPy][PF 6] (RMIm = 1-n-alkyl-3-methylimidazolium, RPy = 1-n-alkylpyridinium) were applied as ionic solvents and toluene is used as solvent for the organic phase. Molybdenum salts immobilized in RTILs constituted a reusable and efficient heterogeneous catalyst system. A maximum conversion (>99%) was achieved for reduction of diphenyl sulfoxide to diphenyl...
Molybdenum liquid salts immobilized on ionic liquid-modified silica as efficient heterogeneous catalysts for sulfoxide reduction
, Article Tetrahedron Letters ; Volume 54, Issue 29 , 2013 , Pages 3765-3768 ; 00404039 (ISSN) ; Ghazali Esfahani, S ; Sharif University of Technology
2013
Abstract
Two room temperature liquid salts containing molybdenum(VI), [BMIM] 2[MoO2(NCS)4] (1) and [DMIM] 2[MoO2(NCS)4] (2), were immobilized on ionic liquid-modified silica leading to materials which showed notable catalytic activity for the reduction of sulfoxides into sulfides with triphenylphosphine (PPh3). The molybdenum liquid salts immobilized on the supported ionic liquid phase could be reused at least for three catalytic cycles without significant loss of activity
Epoxidation of olefins catalyzed by some cis-dioxomolybdenum(VI)-tridentate schiff base complexes with tert-butyl hydroperoxide
, Article Scientia Iranica ; Volume 17, Issue 2 C , 2010 , Pages 131-138 ; 10263098 (ISSN) ; Ghazali Esfahani, S ; Sharif University of Technology
2010
Abstract
Some cis-dioxomolybdenum (VI) complexes with tridentate Schiff base ligands derived from salicylaldehyde and aminophenols, aminoalcohol or o-aminobenzenethiol were examined as catalysts for epoxidation of different aliphatic and aromatic olefins, with tert-butyl hydroperoxide as oxidant. All complexes exhibited high activity and selectivity for epoxidation of aliphatic substrates during a short time period (95% conversion of cyclooctene after 30 min). The epoxide yield increased with the nucleophilic character of olefin. The catalysts activation strongly depends on the reaction temperature and nature of the solvent. Epoxidation of olefins by these catalysts is inhibited by ligands or...
The Particle-Field Theory On The Possibility of New Formulation of Micro-phenomena
,
M.Sc. Thesis
Sharif University of Technology
;
Shafiee, Afshin
(Supervisor)
Abstract
In this thesis we are going to explore a new formalism in micro domain which describes quantum phenomena in a realistic casual fashion by introducing an unified concept of matter, energy, and Information. In this theory, a micro-entity, e.g. an electron, is a combination of a particle and its associated field integrated to a new entity called particle-field. The dynamics of such system will be analyzed. Then, some quantum examples which have controversial aspects will be discussed within the new theory. In a generalized form of formalism, the non-linear Schrödinger Equation is introduced, which enables us to predict some experimental data for common Quantum Mechanical stationary systems....
Technology Roadmap for High Altitude Airship, Based on Conceptual Design of an Airship System
, M.Sc. Thesis Sharif University of Technology ; Mazaheri, Karim (Supervisor)
Abstract
The main focus of this project is to define necessary technologies in design and production of a high altitude airship and provide a roadmap that show how appropriate actions can be conducted toward technology, product and market in the next ten years in Iran. Here, we have surveyed the role of design parameters in the performance of high altitude airship. In the sequel according to the specific final mission, the required technologies and infrastructures are defined.The case of airship technology acquisition for Iran basically can be adapted to the “Technology Catchup”. Hence, we propose a new methodology to provide a technology roadmap with the “technology catchup” approach, then develop...
A Counting Formula for the Kervaire Semi-Characteristic
, M.Sc. Thesis Sharif University of Technology ; Esfahani Zadeh, Mustafa (Supervisor)
Abstract
Similar to the classical Poincare-Hopf index formula for the Euler characteristic, Zhang gave a counting formula for the Kervaire semi-characteristic of a 4q+1 manifold. We first study Witten deformation techniques in the proof of the Poincare-Hopf formula. Then we will represent Zhang’s formula which uses similar analysis. Both these formulas establish a connection between topological and geometrical data on a manifold. Both proofs will be analytical. Index theory will play the ’bridge’ between the topology and analysis. We begin with an analytic interpretation of the topologically defined quantities as indices of differential operators. We deform the operators with respect to appropriate...
Molybdenum(VI) Complexes and Palladium Nanoparticles in Ionic Liquid-Liquid Biphasic and Supported Ionic Liquid phase (SILP) Catalysis, and Green Catalytic Processes using Polymeric Ionic Liquids (PILs
, Ph.D. Dissertation Sharif University of Technology ; Bagherzadeh, Mojtaba (Supervisor)
Abstract
In this thesis, ionic liquids and polymeric ionic liquids were investigated as solvent and support for immobilization of molybdenum and palladium catalysts. Three newly synthesized room temperature ionic liquids containing molybdate anion, [DMIm][MoO2(NCS)4], [RPy][MoO2(NCS)4] (R = butyl or decyl), and previously reported [BMIm][MoO2(NCS)4] were used as catalysts for the reduction of sulfoxides. For facilitating the recyclability of the catalysts, the ionic liquid solvents, [RMIm][PF6] and [RPy][PF6] (RMIm=1-n-alkyl-3-methylimidazolium, RPy= 1-n-alkylpyridinium), were applied to immobilize molybdenum catalysts. These catalysts showed high catalytic activity for sulfoxide reduction in this...
Synthesis of Silver Based Nanocomposite
, M.Sc. Thesis Sharif University of Technology ; Bagheri, Habib (Supervisor)
Abstract
Recently, conductive nanocomposites have found great deals of attentions due to their vast applications in different fields. According to the definition of nanocomposite, the filler component should be in the range of 10-100 nm. In this study, silver nanoparticles was used as filler with 4 nm size and synthesized by microemulsion method that is known as the best approach for fabricating silver nanoparticles with small sizes, narrow size distribution and high stability.
Copoly (ortho-phenylenediamine/dopamine) was used as matrix component. Ortho-phenylenediamine is one of the conductive polymers that was used less than other conductive polymers such as polyaniline in this research area....
Copoly (ortho-phenylenediamine/dopamine) was used as matrix component. Ortho-phenylenediamine is one of the conductive polymers that was used less than other conductive polymers such as polyaniline in this research area....
Presentation of Knowledge Management Framework for Project-Based Organizations
, M.Sc. Thesis Sharif University of Technology ; Shadrokh, Shahram (Supervisor)
Abstract
Knowledge is an organization asset that if used in the direction of organization’s strategic mission, can provide values for the organization. Therefore, many organizations such as NASA, Siemens; and Microsoft have invested in order to improve their knowledge management practices. Many organizations have not been successful in implementing appropriate knowledge management and incurred by huge expenses, while others can use and improve their locations among their competitors in the business. The reason behind many of these organizations were ignoring factor(s) that have direct undeniable effect on result from organization’s knowledge management.
The framework of knowledge management is a...
The framework of knowledge management is a...
Sutures, Taut Manifolds and the Topology of 3-Manifolds
, M.Sc. Thesis Sharif University of Technology ; Esfahani Zadeh, Mostafa (Supervisor)
Abstract
In this essay we focus on the question of whether a 3-manifold (possibly with bound- ary) like M supports a codimension-1 transversely oriented foliation like F , such that F is transverse to ∂M and does not have Reeb components. If such foliation exists, then ∂M is necessarily a (possibly
empty) union of tori and (based on the works of Novikov, Reeb and Rosenberg) M is either S2 × S1(with F being the prod- uct foliation) or M is irreducible. In a paper by David Gabai, which we discuss, the sufficiency of these conditions is proved in case of non-trivial second homology group.Furthermore, from the works of Thurston it is concluded that compact leaves of such foliation are norm minimizing...
empty) union of tori and (based on the works of Novikov, Reeb and Rosenberg) M is either S2 × S1(with F being the prod- uct foliation) or M is irreducible. In a paper by David Gabai, which we discuss, the sufficiency of these conditions is proved in case of non-trivial second homology group.Furthermore, from the works of Thurston it is concluded that compact leaves of such foliation are norm minimizing...
Chern–Weil Theory Extended to a Class of Infinite Dimensional Bundles
, M.Sc. Thesis Sharif University of Technology ; Esfahani Zadeh, Mostafa (Supervisor)
Abstract
Given a principal bundle a characteristic class is an element of the cohomology al- gebra of the classifying space of structure group of the bundle with coefficients in a commutative ring with unit ,which have a functorial property .When the structure groupe of the bundle is a Lie group and the coefficient ring is the real or complex num- bers , the Chern–Weil approach provides a geometric construction of char-acteristic classes. Classical Chern–Weil formalism relates geometry to topology, assigning to the cur- vature of a connection, de Rham cohomology classes of the underlying manifold.This theory developped in the 40’s by Shiing-ShenChern and Andre Weil which can be seen as a generalisation...
Enhancing Recommender Systems Using Analysis of Groups' Influence on Users in Social Networks
, M.Sc. Thesis Sharif University of Technology ; Habibi, Jafar (Supervisor)
Abstract
Rapid growth in science and technology has created vast diversity in products, services and needs of people and groups. As the Internet and web technologies have progressed, a web-based solution to explore products of either a specific domain or multiple domains is mandatory. One of the main challenges in these systems is learning users’ preferences to recommend items possibly interesting to the user. Social network of the users is one of the sources that can inject additional information about them which can be exploited to improve accuracy of the system. Depending on the method, the performance, accuracy and personalization may differ .One of the most popular methods to extract this...
Synthesis and characterisation of β-tricalcium phosphate coating on zirconia toughened alumina by biomimetic method
, Article Advances in Applied Ceramics ; Volume 112, Issue 3 , 2013 , Pages 140-145 ; 17436753 (ISSN) ; Nemati, A ; Salahi, E ; Sharif University of Technology
2013
Abstract
The present work studied bioactive coatings on the surface of ceramic biomaterials. Zirconia toughened alumina (ZTA) composites containing 15 mol.-%. Partially stabilised zirconia was prepared after 1 h sintering at 1550°C. Apatite layers were then coated onto the surfaces of composites by the biomimetic method using 1·5-2 multiply concentrations of simulated body fluid (SBF). Before treatment in SBFs, a sodium silicate layer was employed as nucleating agent to induce the formation of a calcium phosphate layer. The effect of immersion time on the morphology of the precipitate was monitored with a scanning electron microscope. X dot maps revealed that there is a relationship between...