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    Influence of Shear Wall Positioning in Design of Concrete Frames

    , M.Sc. Thesis Sharif University of Technology Haghighat, Reza (Author) ; Maleki, Shervin (Supervisor)
    Abstract
    Numerous research is available in the literature regarding shear walls. These have considered parameters like wall cross-section, Reinforcement configuration, boundary elements, etc. In addition, seismic and wind loading behavior has been discussed. Currently, the software ETABS is used extensively in automatic design of shear walls, The programs design bases are investigated in this thesis in ragards to flexural, shear and boundary elements of shear walls under seismic loading. The attachment of wall elements to frame (column) elements is of particular interest in this study  

    Feasibility Study and Conceptual Design of Solar Energy Source for Surface Train System

    , M.Sc. Thesis Sharif University of Technology Maleki, Sina (Author) ; Durali, Mohammad (Supervisor)
    Abstract
    Advancements in solar powered systems bring about the possibility for today’s transportation systems to be operated and driven by such a clean and renewable source of energy. The challenging point of this combination is to draw high power levels from such a low power density source of energy. As a result, employing an efficient power storage and management system becomes inventible. The subjects of this research are to design a grid connected system and evaluate its performance and feasibility in a real application (Tehran- Mehrshahr surface train – Tehran 5th Metro Line). The task includes sixteen pairs of DC transmission lines which are powered by CIGS solar module technology and four... 

    Behavior of Angle Shear Connectors

    , M.Sc. Thesis Sharif University of Technology Tahmasbi, Farzad (Author) ; Maleki, Shervin (Supervisor)
    Abstract
    The application of composite systems has rapidly advanced in bridge and building construction. Shear connectors are the most basic parts of the composite systems.The connectors transfer the shear forces between the slab and the beam. They also prevent separation of the slab from the beam.
    Therefore researchers have done widespread studies on the behavior of shear connectors and their load carrying capacity. Steel angles are one of the shear connectors that can be used incompositesystems. Only limited number ofstudies has investigated thebehavior of thistype of connector.
    The purpose of this thesis is to investigate the behavior of angle shear connectors embedded in solid concrete... 

    Gusset Plate Connectionmodels

    , M.Sc. Thesis Sharif University of Technology Monjezi, Ahmad (Author) ; Maleki, Shervin (Supervisor)
    Abstract
    Lateral forces on structures are transferred to braces as tensile and compressive loads. These loads enter the beams and columns through the gusset plates. The gusset connections to the beams and columns must be such that they be able to pass the loads through themselves. So far, five analytical models have been proposed for this connection and only one of them is recommended by AISC. These models estimate the existing forces and moments on the connection. The analytical models are: model 1 (KISS), model 2 (2A-AISC), model 3 (Thornton), model 4 (Ricker) and model 5 (Richard). Among these models, only model 3 is recommended by AISC because the others are more conservative. It should be noted... 

    Development of an Analytical Framework for Evaluation of Climate Change Mitigation Policies on Iran’s Energy Security

    , M.Sc. Thesis Sharif University of Technology Eshraghi, Hadi (Author) ; Maleki, Abbas (Supervisor)
    Abstract
    Climate change and energy security are key drivers for future energy policy. While energy security has been a pillar of energy policy for about a century, concern about climate change is more recent and is bound to radically change the landscape of energy policy. Policy makers are now under increasing pressure to address these twin challenges: to develop cost-effective policies that will both ensure the security of our energy system and reduce greenhouse gas emissions.
    Main Effort in this Project is to construct an integrated model of Iran’s energy system to serve as a policy analysis tool, by which policymakers are able to identify the future effects of a wide range of policies in... 

    Effects of Cable Arrangements on Seismic Performance of Cable-stayed Bridges

    , M.Sc. Thesis Sharif University of Technology Heidari, Siamak (Author) ; Maleki, Shervin (Supervisor)
    Abstract
    Cable-stayed bridges are the most economical solution for spans ranging from about 200 to 1000 meters. They have become more popular in recent decades due to their efficiency and appearance. The need to understand their seismic beahvior is apparent and any improvement can be useful. The main purpose of this study is to determine the effect of using three lateral cable arrangement groups namely, cross system, pulley system and spatial lateral cable system with two transversally inclined cable planes on seismic performance of cable-stayed bridges. In this research, the seismic consequences of these arrangements with interactions of key parameters like, the main span length and deck to pylon... 

    The Shear Lag Effects on Welded Steel Single and Double Angle and HSS Tension Members

    , M.Sc. Thesis Sharif University of Technology Abedin, Mohammad (Author) ; Maleki, Shervin (Supervisor)
    Abstract
    The shear lag phenomenon is one of the effective factors in determining the tensile capacity of tension members. In this phenomenon, there are various factors including the size and type of the cross-section, the type of connection, the length of connection, thickness of gusset plate, etc. are effective. The previous studies which are the basis of the specification equations, have been conducted on the cross-sections with bolted and riveted connections, while no study has been conducted to determine the effects of some of these factors yet. Using numerical methods, the present study investigates and compares each of the effective parameters on shear lag phenomenon on the single and double... 

    (Assessing the Role of Carbon Capture and Storage Technology on Iran’s Oncoming Energy System(Technology Deployment Policy Making

    , M.Sc. Thesis Sharif University of Technology Banan, Zoya (Author) ; Maleki, Abbas (Supervisor)
    Abstract
    Based on International Energy Agency studies, achievement of 450 ppm CO2-equivalent emission target in global emission means that the CO2 emissions in 2050 must be reduced to %50 of 2005 level, and this implies that a portfolio of emission reduction policies and strategies need to be exploited through current century.
    At the present time, Carbon Capture and Storage (CCS) Technology is a dominant strategy among all the long-term carbon abatement strategies in many countries. Nevertheless, its potential as a climate mitigating option will be proved, only if it is implemented in the countries which are developing at a great pace and taking advantage of fossil fuels in order to afford their... 

    Liquid-liquid-liquid microextraction and high performance liquid Chromatography for Seperation and Determination of Estrogens in Aquatic Media

    , M.Sc. Thesis Sharif University of Technology Maleki, Hossein (Author) ; Bagheri, Habib (Supervisor)
    Abstract
    Liquid-liquid-liquid microextraction (LLLME) is a new miniaturized liquid extraction to preconcentrate and purify for ionizable analytes. In LLLME firstly analytes extracted in an organic phase, and subsequently back-extracted into a second aqueous phase. Main advantages of LLME are their speed, simplicity, negligible volume of solvents, analytical precision, short sample preparation and low cost. This technique was shown to be an efficient preconcentration method for the extraction of estrone and estriol from biological samples. A basic microdrop in the tip of microsyringe was fixed in the organic layer over the sample solution. After extraction for a preset time, the microdrop was... 

    Angle Shear Connectors Capacity

    , M.Sc. Thesis Sharif University of Technology Khalilian, Marzieh (Author) ; Maleki, Shervin (Supervisor)
    Abstract
    The steel-concrete composite beams are increasingly used in bridge and building construction in recent years. A shear connection between the steel and concrete should be provided to effectively transfer the shear force and to make the two materials act as a single unit. The mechanical shear connectors provide this means. They are the essential component of any composite beam system. Many studies have been performed on shear connectors and many different steel shapes have been suggested for connectors. The steel studs and channels are the most popular code accepted connectors. However, economic considerations continue to motivate the development of new products.
    Present knowledge of the... 

    Behavior of Angle-Shape Shear Connectors With Different Tilted Angles in Steel-Concrete Composite Systems

    , M.Sc. Thesis Sharif University of Technology Khorramian, Koosha (Author) ; Maleki, Shervin (Supervisor)
    Abstract
    According to recent researches, angle-shape shear connectors are appropriate to transfer longitudinal shear forces across the steel-concrete interface. This study investigates the effect of tilted angle on capacity and behavior of angle-shape shear connectors. In this study, we consider two different tilted angles. Push-out tests consisting of eight specimens made of reinforced concrete and different angle-shapes were conducted. Specimens have tilted anglesof 112.5 and 135 degrees between the angle leg and steel beam. Two different failure modes were observed consisting of concrete crushing-splitting and angle fracture. In addition, a nonlinear finite element model of these push-out... 

    Experimental and Analytical Study on Pipe Shear Connectors

    , M.Sc. Thesis Sharif University of Technology Nasrollahi, Saeed (Author) ; Maleki, Shervin (Supervisor)
    Abstract
    In this thesis the shear strength of pipe shear connector is investigated experimentally and numerically. The numerical analysis uses a nonlinear finite element model of the push-out specimen. The specimens consist of the pipe shear connector, steel beam, concrete slab and embedded steel rebar for concrete confinement. Eight push-out specimens are constructed with different pipe sizes and concrete strength. The results are used in a finite element parametric study to evaluate the strength of such connectors for all practical ranges of pipe size and concrete strength. It is shown that pipe connectors are more effective in transferring shear forces than angle and channel and stud connectors.... 

    Assessment of Caspian Gas Transit and its Effects on the Interests of the Iranian Desired

    , M.Sc. Thesis Sharif University of Technology Khakpour, Hossein (Author) ; Maleki, Abbas (Supervisor)
    Abstract
    In this project a model for the analysis and assessment of gas transit in the Caspian Sea and its effects on the desired benefits of the approach of decision-making, has been developed.
    The first comprehensive review of the supply and demand of gas in the world and the countries of the Caspian region and the cast has been affecting world energy developments.After a comprehensive analysis of the status of the gas transit routes from the Caspian region and provided. Then, using the Delphi method and elite views the main criteria related to gas transit and affecting the interests of the countries of the Caspian region to determine the detailed criteria for each main criterion was determined... 

    Investigation of Dynamic Response of Foundations on Sandy Soils to Two-Way Horizontal Harmonic Loading by Physical Model Tests

    , M.Sc. Thesis Sharif University of Technology Maleki, Jafar (Author) ; Jafarzadeh, Fardin (Supervisor)
    Abstract
    Increasing requirements of industries and research institutes to analytical results of interaction soil-foundation related systems, reveals the importance of the dynamic impedance functions than ever before. The dynamic impedance function relations are presented for massless rigid foundations which is possible to obtain dynamic response of foundations for different frequencies and masses accordingly. In this study, the dynamic impedance functions were investigated using physical modeling tests on sandy soil with finite thickness soil stratum over bedrock. The tests were carried out inside a steel container of dimensions 1*1*0.8m in length, width and height respectively which was filled into... 

    Infilled-pipe damper

    , Article Journal of Constructional Steel Research ; Volume 98 , July , 2014 , Pages 45-58 ; ISSN: 0143974X Maleki, S ; Mahjoubi, S ; Sharif University of Technology
    2014
    Abstract
    This paper introduces a new passive control device for protecting structures against earthquakes. The device consists of two welded pipes which have two smaller pipes inside them and the spaces between the pipes are filled with metals such as lead or zinc. The device is loaded in shear and takes advantage of plastification of the outer pipes, the inner pipes and the infilled metals, and the friction between metals as energy absorption mechanisms. Quasi-static cyclic tests are performed on six specimens all showing stable hystereses and high damping. A finite element model is developed and calibrated against test results. The model is used to find the optimum sizes of pipes needed for a... 

    Seat width requirement for skewed bridges under seismic loads

    , Article Scientia Iranica ; Vol. 21, issue. 5 , 2014 , pp. 1471-1479 ; ISSN: 10263098 Maleki, S ; Bagheri, S ; Sharif University of Technology
    2014
    Abstract
    In this paper, the dynamic characteristics of skewed bridges are explored analytically. Closed form solutions for translational and torsional periods of free vibration and mode shapes are given for slab-girder skewed bridges. Moreover, the seismic displacement of the deck of skewed bridges is calculated using the response spectrum method and its skew term is compared with the requirement of AASHTO. The effects of seismic force resisting elements, such as elastomeric bearings and end diaphragms are included. It is shown that the skew term in AASHTO's equation can underestimate the seat width requirement for some bridges. A new skew term for the bridge seat width requirement is suggested  

    Numerical study of Slotted-Web-Reduced-Flange moment connection

    , Article Journal of Constructional Steel Research ; Volume 69, Issue 1 , February , 2012 , Pages 1-7 ; 0143974X (ISSN) Maleki, S ; Tabbakhha, M ; Sharif University of Technology
    2012
    Abstract
    Reduced Beam Section (RBS) and Slotted Beam Web (SBW) are two types of seismic resistant moment connections that were introduced after the 1994 Northridge earthquake. These connections have been tested under cyclic loading and have had acceptable performance. In this paper, a new hybrid connection is introduced that is composed of RBS and SBW and is named Slotted-Web-Reduced- Flange (SWRF). Nonlinear finite element analyses are performed on SWRF under cyclic loading. It is shown that the new connection in some cases performs better than its RBS and SBW predecessors. The effects of panel zone strength, continuity plates and slot length are also investigated  

    Dual-pipe damper

    , Article Journal of Constructional Steel Research ; Volume 85 , 2013 , Pages 81-91 ; 0143974X (ISSN) Maleki, S ; Mahjoubi, S ; Sharif University of Technology
    2013
    Abstract
    In this paper, a new passive earthquake energy dissipative device, called the dual-pipe damper (DPD), is introduced, tested and analytically studied. The device consists of two pipes welded at selected locations and loaded in shear. The inelastic cyclic deformation dissipates energy mainly through flexure of the pipe body. However, at large displacements a tension diagonal forms in the middle of the device which further adds to stiffness and strength. The strength, stiffness and energy dissipation of the DPD is more than two single pipe dampers that were previously studied. Cyclic quasi-static tests were performed on four samples of DPD. Excellent ductility, energy absorption and stable... 

    Evaluation of Seismic Performance Factors for Tension-only Bracing

    , M.Sc. Thesis Sharif University of Technology Lagzian, Majid (Author) ; Maleki, Shervin (Supervisor)
    Abstract
    Tension-Only Concentrically Braced Frame (TOCBF) incorporates very slender bracing members, such as single angles, that are unable to dissipate much energy in compression due to their negligible buckling strength. Alternating tension yielding and elastic compression buckling of the bracing elements result in rapid strength degradation during strong motions, which translates into deteriorating pinched hysteresis loops. Based on this unfavorable behavior, it is not recommended to employ TOCBF system for medium and high-rise buildings located in active seismic areas. However, as a result of its inexpensivity and simplicity to design, the TOCBF system is used prevalently in low-rise steel... 

    Artificial neural network modeling of Pt/C cathode degradation in pem fuel cells

    , Article Journal of Electronic Materials ; Volume 45, Issue 8 , 2016 , Pages 3822-3834 ; 03615235 (ISSN) Maleki, E ; Maleki, N ; Sharif University of Technology
    Springer New York LLC  2016
    Abstract
    Use of computational modeling with a few experiments is considered useful to obtain the best possible result for a final product, without performing expensive and time-consuming experiments. Proton exchange membrane fuel cells (PEMFCs) can produce clean electricity, but still require further study. An oxygen reduction reaction (ORR) takes place at the cathode, and carbon-supported platinum (Pt/C) is commonly used as an electrocatalyst. The harsh conditions during PEMFC operation result in Pt/C degradation. Observation of changes in the Pt/C layer under operating conditions provides a tool to study the lifetime of PEMFCs and overcome durability issues. Recently, artificial neural networks...