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Effect of water-cement ratio on abrasive strength, porosity and permeability of nano-silica concrete
, Article World Applied Sciences Journal ; Volume 17, Issue 8 , 2012 , Pages 929-933 ; 18184952 (ISSN) ; Peroti, S ; Rahmani, K ; Rahemi, L ; Sharif University of Technology
2012
Abstract
Today, due to rapid development of construction of hydraulic structures like dams, the constituent material used in concrete and its durability in these kinds of structures has gained dominant interests and importance. One of the important factors of concrete durability in these structures is its resistance against abrasion due to crash of particles carried out as hydrated crystalline particulate matter. To enhance the abrasion resistance of concrete, different methods have been offered and investigated by many research3ers/ The aim of present article is to investigate the important parameter i.e. water-cement ratio on abrasive strength, porosity and the coefficient of hydraulic conductivity...
The effect of water-cement ratio in compressive and abrasion strength of the nano silica concretes
, Article World Applied Sciences Journal ; Volume 17, Issue 4 , 2012 , Pages 540-545 ; 18184952 (ISSN) ; Rahmani, K ; Peroti, S ; Rahemi, L ; Sharif University of Technology
2012
Abstract
Development and construction of hydraulic structures like dams, the concrete durability in these kinds of structures has gained special attention. One of the crucial factor in concrete technology is it durability in hydraulic structures. Concrete has to resist against abrasion due to the crash of particles carried by water. To enhance the abrasion resistance of concrete different methods have been offered. In the present stud, the role of water-cement ratio in compressive and abrasion strength of nano silica concrete was investigated. The constructed concrete samples with 3% nano silica and water-cement ratios of 0.33, 0.36, 0.40, 0.44 and 0.50 were experimented. Other design features...
N-doped ZnO-CuO nanocomposite prepared by one-step ultrasonic spray pyrolysis and its photocatalytic activity
, Article Chemical Physics Letters ; Volume 705 , 2018 , Pages 19-22 ; 00092614 (ISSN) ; Sabour Rouhaghdam, A ; Nazari, M ; Sharif University of Technology
Elsevier B.V
2018
Abstract
Nanocomposite thin film of N-doped ZnO-CuO was deposited on glass substrate using ultrasonic spray pyrolysis method. Zinc acetate, copper acetate and ammonium acetate with different molar ratios were dissolved in water and used as precursors. A crumpled-shape morphology consisting of nanometer-sized particles was observed with FESEM. The elemental composition was evaluated with EDX analysis and the presence of nitrogen, oxygen, copper and zinc was confirmed. XRD analysis revealed the presence of ZnO and CuO crystalline phases with crystallite size of about 18 nm. The prepared nanocomposites exhibited high photocatalytic activity in degradation of methyl orange under UV light irradiation. ©...
Computer simulation of knee arthrometry to study the effects of partial ACL injury and tibiofemoral contact
, Article 30th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS'08, Vancouver, BC, 20 August 2008 through 25 August 2008 ; 2008 , Pages 895-898 ; 9781424418152 (ISBN) ; Farahmand, F ; Rezaeian, T ; Parnianpour, M ; Sharif University of Technology
IEEE Computer Society
2008
Abstract
We simulated the knee arthrometry test to obtain a deeper understanding of the joint's stability behavior and interpret the arthrometric results more effectively. A 2D sagittal plane finite element model of the lower limb in the standard configuration of knee arthrometry was developed using ANSYS APDL. A detailed model of the knee joint was considered including the femoral articulating contour represented by an ellipse, the tibial plateau represented by a circular arc, and four major knee ligaments and their individual bundles represented by linear and nonlinear tensile springs. A deformable layer of articular cartilage was also considered over the tibial plateau to simulate the bones...
Providing Methods for Reducing and Estimating the Power Consumption of Wireless Networks on Chip
, M.Sc. Thesis Sharif University of Technology ; Tabandeh, Mahmoud (Supervisor) ; Rahemi, Bijan (Supervisor)
Abstract
In recent years, the possibility of building large systems on chip, called SoC is provided. By scaling the technology, designing Socs will face numerous challenges. The Noc paradigm, has resolved many of the SoC’s problems, by deploying network properties in the structures of on chip interconnections. Today, with advances in the semiconductor industry, we can implement broadband wireless antennas, which are integrated on chip. Such NoCs are called WNoC. Due to immaturity of WNoCs, there still exist big challenges, providing routing algorithm and controlling shared medium via MAV layers, for them. In this project, we will provide a routing algorithm based on tag switching, and then, after...
Long-Term Analysis of Water Balance Components and Water Level Changes of Lake Urmia using a Combination of Field aAnd Remote Sensing Data
, M.Sc. Thesis Sharif University of Technology ; Safaie, Ammar (Supervisor)
Abstract
In recent years, global salt lakes have faced severe environmental challenges. Lake Urmia, the world’s second-largest hyper saline lake, is located in the northwest of Iran, has experienced a significant shrinkage in last years. Lake Urmia is a terminal lake where water enters through precipitation and rivers inflow and loses through evaporation. Analysis of long-term trends (1990-2018) using the Mann-Kendall test indicates no significant trend in precipitation, an increasing trend in evaporation, and a decreasing trend in river discharge. However, precipitation during 1990-1999 (beginning of accelerated lake drying) showed a decreasing trend. An investigation of the correlation between...
Bioethanol supply chain network design considering land characteristics
, Article Renewable and Sustainable Energy Reviews ; Volume 119 , 2020 ; Torabi, S. A ; Avami, A ; Jolai, F ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
Biomass is becoming an increasingly widespread source of energy. Yet land, as one of the most important resources in biomass production, is surprisingly understudied in the literature of biomass supply chain planning. This study proposes a novel framework that combines the literature of bioethanol supply chain design with agricultural land planning to simultaneously address optimal supply chain planning and sustainable land use in a bioethanol supply chain. A bi-objective mixed-integer linear programming (MILP) model is proposed to formulate the optimal design and planning of a bioethanol supply chain network considering competition of food and biomass feedstock over the available croplands....
Computer Simulation of Arthrometric Diagnosis of Partial ACL-Injured Knee
, M.Sc. Thesis Sharif University of Technology ; Farahmand, Farzam (Supervisor) ; Parnianpour, Mohammad (Supervisor)
Abstract
Knee pain and injuries are very common in athletes. Anterior cruciate ligament (ACL) injury is one of the most important reason of knee acute and chronic pains. As ACL plays a significant role in knee stability and due to amount of reported ACL related injuries, much effort has been placed on finding proper and on time diagnosis and treatment of these injuries. Arthrometric methods are the most non-invasive reliable diagnosis option; however they are not fully capable of separating partial injuries from intact joint. This weakness can be investigated by quantifying the tests using computer simulations; so far few studies have been conducted toward this goal. In this study a two dimensional...
Advances in heuristic signal processing and applications
, Book ; Chatterjee, Amitava ; Nobahari, Hadi ; Siarry, Patrick
Springer
2013
Abstract
There have been significant developments in the design and application of algorithms for both one-dimensional signal processing and multidimensional signal processing, namely image and video processing, with the recent focus changing from a step-by-step procedure of designing the algorithm first and following up with in-depth analysis and performance improvement to instead applying heuristic-based methods to solve signal-processing problems. In this book the contributing authors demonstrate both general-purpose algorithms and those aimed at solving specialized application problems, with a special emphasis on heuristic iterative optimization methods employing modern evolutionary and swarm...
Characterization of Ni-P-SiO2-Al2O3 nano-composite coatings on aluminum substrate
, Article Materials Chemistry and Physics ; Volume 189 , 2017 , Pages 207-214 ; 02540584 (ISSN) ; Afshar, A ; Sadreddini, S ; Ghanbari, A. A ; Sharif University of Technology
Elsevier Ltd
2017
Abstract
In the present work, nano-composites of Ni-P-SiO2-Al2O3 were coated on a 6061 aluminum substrate. The surface morphology of the nano-composite coating was studied by field emission scanning electron microscopy (FESEM). The amount of SiO2 in the coating was determined by Energy Dispersive Analysis of X-Ray (EDX) and the crystalline structure of the coating was examined by X-ray diffractometer (XRD). All the experiments concerning the corrosion behavior of the coating carried out in 3.5%wt NaCl solution and evaluated by electrochemical impedance spectroscopy (EIS) and polarization technique. The results showed that an incorporation of SiO2 and Al2O3 in Ni-P coating at the SiO2 concentration of...
Methodology of Religious ScienceWith Respect to Dr.Golshani’s Theory of Religious Scienceand Dr.Khosropanah’s Hikmai-Ejtihadi’s Pattern on Humanities
, M.Sc. Thesis Sharif University of Technology ; Golshani, Mehdi (Supervisor) ; Khosropanah, Abdolhossien (Co-Advisor)
Abstract
If we accept that there is a thing called “religious Science”, then we should accept that, all of its scientific elements should be based on, or be compatible with religion (in its general meaning). So, here is the question: Is there a particular “religious methodology” required for the “religious science”? Does “religious”, as an adjective also applies to methodology of science? Anyway, if we want to generate “religious science” based on religious foundations, we should characterize our position about “methodology of religious science”. Negligence of this important subject would cause a theoretical vacuum in discussions about religious science. In this thesis, after explaining some general...
Characterization of Elecroless Ni-P-Al2O3-SiO2 Nano-composite Coating on Aluminium
, M.Sc. Thesis Sharif University of Technology ; Afshar, Abdollah (Supervisor) ; Dolati, Abolghasem (Supervisor)
Abstract
In this study Ni-P-Al2O3-SiO2 nano composite coating developed on aluminium alloy 6061 using electroless method. Due to oxidation of aluminium, a double zincate pretreatment performed to obtain proper adhesion of coating on substrate. Effect of solution temperature and heat treatment on thickness and property of nano composite coating was studied. Furthermore, effect of concentration of nano particles in electroless solution on thickness, morphology, micro hardness, wear behavior, corrosion resistance and particle content in coating were investigated. Field emission scanning electron microscopy (FESEM, Hitachi S-4160) with energy dispersive spectroscopy (EDS) was used to evaluate morphology...
Development of an Evolutionary Algorithm Based on Surrogate Models to be used in Multi-disciplinary Design Optimization of a Flying Vehicle
, M.Sc. Thesis Sharif University of Technology ; Nobahari, Hadi (Supervisor)
Abstract
In this research, multi-disciplinary design optimization (MDO) of a flying vehicle has been done based on the flight simulation. A meta-heuristic algorithm called Multi-objective Adaptive Real-coded Memetic Algorithm (MARCOMA) has been used for optimization. Since solving a MDO problem is a time consuming process, a RBF neural network has been used in the optimization algorithm as a surrogate model. The new algorithm, called MARCOMA+NN, has been tested with some standard benchmarks. MDO problem has six disciplines consists structure, aerodynamic, propulsion, guidance, control, and fire control. The MDO problem has 31 design variables and two objective functions. The objective functions are...
Optimal Design and Real-time Implementation of a Cooperative Guidance Algorithm against a Flying Vehicle
, M.Sc. Thesis Sharif University of Technology ; Nobahari, Hadi (Supervisor)
Abstract
A cooperative aerial system to defense a Ground Station (GS), against an Incoming aerial Targets (IT) is presented. GS is surrounded by given terrains and a group of homogenous Unmanned Aerial Vehicles (UAVs) are employed using a novel online guidance algorithm in a decentralized manner. The proposed algorithm includes loiter, midcourse and terminal phases. During loiter; UAVs follow an optimal circular path. IT is supposed to approach GS along an optimal low altitude trajectory with respect to the terrains. UAVs are informed the initial position and velocity of IT and they are unaware of IT trajectory. Each UAV decides on whether to engage with IT or not, and shares its decision with other...
Synthesis and Characterization of PVDF Magnetic Nanocomposite
, M.Sc. Thesis Sharif University of Technology ; Forounchi, Massoud (Supervisor)
Abstract
PVDF (polyvinylidene fluoride) magnetic nanocomposite films were prepared by solution casting using two types of nanomagnetic particles: (i) magnetic nanoparticles synthesized by using an alkaline solution of mixed ferrous/ferric salts along with oleic acid as a coating agent at 70˚C; (ii) Fe3O4 nanoparticles prepared by hydrolysis of aqueous solution of ferrous/ferric salts with potassium hydroxide at room temprature. Scanning electron microscopy (SEM) showed that the PVDF magnetic nanocomposite had a porous structure with Fe3O4 nanoparticles dispersed inside the porous polymer matrix. The presence of crystalline magnetite within the polymer matrix was confirmed by X-Ray diffraction method...
Cooperative Search and Localization of Mobile RF Ground Targets, Using a Group of UAVs
, M.Sc. Thesis Sharif University of Technology ; Nobahari, Hadi (Supervisor)
Abstract
In this project, a method for cooperative search and localization of RF ground moving targets by a group of UAVs is developed. It should be noted that UAVs are just equipped with GPS and directional sensors. Since there is fuel constraint for UAVs, they take fuel from a tanker whenever they require. Moreover, searching method enables the UAVs to see different parts of the desired area with almost uniform distribution. In addition, the proposed approach enables the UAVs to perform a local search with the aim of finding the targets having lost their signal during localization mode. Finally, based upon a fueling decision function the UAVs take turn, approach to the fuel tanker, and start...
Attitude Control of a 3DOF Quadrotor Stand Using Intelligent Back-stepping Approach
, M.Sc. Thesis Sharif University of Technology ; Nobahari, Hadi (Supervisor)
Abstract
In this research a novel intelligent back-stepping control method is developed. This method is robust to sensor noise and external disturbances. In addition, the controller is robust under model uncertainty. This controller does not need precise knowledge of system parameters. This method is based on three methods of: back-stepping control, least squares estimation and a fuzzy compensator. This controller is used to control quadrotor stand witch is like an inverse pendulum. In quadrotor stand modeling, the inverse pendulum effect is considered too, witch is one of the innovations of the research. By doing various simulations, the validity of controller is tested. Also the performance of the...
Cooperative Search and Localization of Aerial Targets, Using a Group of Fixed Wing UAVs
, M.Sc. Thesis Sharif University of Technology ; Nobahari, Hadi (Supervisor)
Abstract
Topic that is investigated in this article include identify and localization a number of aerial target penetrating into a protected by area by a swarm of UAVs is fixed wing. UAVs do not have any prior notice of positioning targets. In addition, it is assumed that lacks any radiation exploitable targets and thus use UAVs for Targets Detection from an active radar system. Obviously this article focus on developing a guidance algorithm UAVs to this particular issue and also as the targets participatory is localization algorithm. In addition, extraction type and performance characteristics radar system required and also performance characteristics of the class of UAVs, which is suitable to...
A New Method for Integrated Controller and Observer Design of a Nonlinear System Using Genetic Programming
, M.Sc. Thesis Sharif University of Technology ; Nobahari, Hadi (Supervisor)
Abstract
The purpose of this paper is to design an integrated controller and observer (ICO) for a nonlinear system using genetic programming. ICO is a function that constructs control command directly from the measured state variables of the system. It means that, this function should imitate the behavior of the observer and controller and control the system with acceptable performance in different initial conditions, at the presence of disturbances and system uncertainties. The complexity of this design method, is not related to the complexity of the plant, in fact, the complexity in plant just effects at run time, but the design procedure does not change. So, if exact model of plant exist, using...
Development of Integrated Model of the Wastewater and Organic Solid Waste Flows to Minimize Environmental Impacts and Maximize Energy Recovery for a Residential Building
, M.Sc. Thesis Sharif University of Technology ; Avami, Akram (Supervisor)
Abstract
Nowdays much of the organic solid waste and wastewater is buried using centralized and traditional methods. This leads to many problems, including groundwater pollution, methane emissions into the atmosphere and rapid transmission of disease. In order to avoid these problems, using a decentralized approach can be a good solution. In this study, recovery of organic waste and wastewater of residential buildings using anaerobic digester as a decentralized way, have been examined. Using experiments, the optimum mass ratio of organic solid waste and wastewater is obtained as 80% and 20% respectively. Biogas production model is developed using mass balance and Balance of electrons in redox...