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    Biodiesel production from Spirulina microalgae feedstock using direct transesterification near supercritical methanol condition

    , Article Bioresource Technology ; Volume 239 , 2017 , Pages 378-386 ; 09608524 (ISSN) Mohamadzadeh Shirazi, H ; Karimi Sabet, J ; Ghotbi, C ; Sharif University of Technology
    Elsevier Ltd  2017
    Abstract
    Microalgae as a candidate for production of biodiesel, possesses a hard cell wall that prevents intracellular lipids leaving out from the cells. Direct or in situ supercritical transesterification has the potential for destruction of microalgae hard cell wall and conversion of extracted lipids to biodiesel that consequently reduces the total energy consumption. Response surface methodology combined with central composite design was applied to investigate process parameters including: Temperature, Time, Methanol-to-dry algae, Hexane-to-dry algae, and Moisture content. Thirty-two experiments were designed and performed in a batch reactor, and biodiesel efficiency between 0.44% and 99.32% was... 

    Experimental and Theoretical Study of Biomass Conversion to Green Fuel by Using Supercritical Fluid

    , M.Sc. Thesis Sharif University of Technology Mohamadzadeh Shirazi, Hamed (Author) ; Ghotbi, Cyrus (Supervisor) ; Karimi Sabet, Javad (Supervisor)
    Abstract
    Nowadays, one of the most basic human problem is how to manage energy resources for sustainable development and how to deal with problems caused by growing energy consumption. Various scenarios are being discussd that the most important of them can be considered research on finding alternative energy sources that are renewable and do not have common pollution. Thus, according to researches carried out until now, using sources such as wind, water, solar biomass, etc. have been proposed. However, due to problems in the development of each of these sources, biomass as the primary option has been introduced. because biomass has several subsidiaries, research shows microalgaes (as a subset) are... 

    Compatibility or Incompatibility of the Evolution Theory with the Teleological Argument

    , M.Sc. Thesis Sharif University of Technology Mohamadzadeh Vatanchi, Mohamad (Author) ; Hosseini Sarvari, Hassan (Supervisor)
    Abstract
    In this article, we will examine the theory of evolution through natural selection and we will show that the evidence in favor of natural selection is so great that today this theory has been fully accepted by the scientific community. The theory of evolution had many philosophical and theological consequences; One of its direct consequences was the weakening of teleological arguments and specifically the argument of William Paley's plan; Because in the light of this theory, the existence of features with functions and complex adaptations of living things can be explained without the need of designing a supernatural agent. Despite this, biology still uses concepts such as function, which has... 

    Capture zone of a partially penetrating well with skin effects in confined aquifers

    , Article Transport in Porous Media ; Volume 91, Issue 2 , January , 2012 , Pages 437-457 ; 01693913 (ISSN) Ataie Ashtiani, B ; Shafei, B ; Rashidian Dezfouli, H ; Mohamadzadeh, M ; Sharif University of Technology
    2012
    Abstract
    The analysis of the capture zone of wells is useful to design pumping systems and wellhead protection programs. In this study, an analytical solution for the head distribution of a partially penetrating well, and semi-analytical methods to determine the geometry of the capture surface are presented. The analytical solution is derived based on an infinitesimal radius under a constant pumping rate in a two-zone confined aquifer. Using the developed solution, a sensitivity analysis is performed to study the influence of skin on the drawdown, location of the stagnation point, maximum horizontal and vertical extent of the capture surface. The results show the efficiency of a partially penetrating... 

    Analysis of Functional Brain Connectivity Using EEG Signals for Classification of Brain States

    , M.Sc. Thesis Sharif University of Technology Ghodsi, Saeed (Author) ; Karbalai Aghajan, Hamid (Supervisor) ; Mohamadzadeh, Hoda ($item.subfieldsMap.e)
    Abstract
    Different perceptual, cognitive, and emotional situations results in a kind of information flow in the brain by means of coordinated neuronal oscillations. Analysing these oscillations, especially synchronizations of different brain regions, can illustrate the brain response to the aforementioned situations. In the literature, connectivity between brain regions is divided into the three groups of structural, effective, and functional, s.t. the first one referes to the connectivity between nearby regions, while the second and third ones focus on the synchronization of oscillations of arbitrary located regions. Although EEG is not the best choice for analyzing functional connectivity between... 

    An efficient tabu search algorithm for the single row facility location problem [electronic resource]

    , Article European Journal Of Operational Research ; Vol. 205, No. 1, pp. 98-105 Samarghandi, H. (Hamed) ; Eshghi, Kourosh ; Sharif University of Technology
    Abstract
    The general goal of the facility layout problem is to arrange a given number of facilities to minimize the total cost associated with the known or projected interactions between them. One of the special classes of the facility layout problem is the Single Row Facility Layout Problem (SRFLP), which consists of finding an optimal linear placement of rectangular facilities with varying dimensions on a straight line. This paper first presents and proves a theorem to find the optimal solution of a special case of SRFLP. The results obtained by this theorem prove to be very useful in reducing the computational efforts when a new algorithm based on tabu search for the SRFLP is proposed in this... 

    Sensitivity analysis of matching pennies game [electronic resource]

    , Article Mathematical and Computer Modelling ; Volume 51, Issues 5–6, March 2010, Pages 722–735 Yarmand, H. (Hamed) ; Eshghi, Kourosh ; Sharif University of Technology
    Abstract
    In this paper, we have discussed the results of sensitivity analysis in a payoff matrix of the Matching Pennies game. After representing the game as a LP model, the sensitivity analysis of the elements of the payoff matrix is presented. The game value and the optimal strategies for different values of parameters are determined and compared  

    Evaluation of Plasmid Transmission in Bacillus Subtilis by Cell Wall Modification

    , M.Sc. Thesis Sharif University of Technology Mohamadzadeh, Mohammad Sadegh (Author) ; Roosta Azad, Reza (Supervisor) ; Aghamollaei, Hossein (Supervisor)
    Abstract
    Today, almost all the country's needs in the field of industrial enzymes are met through imports. In this regard, much attention has been paid to the industrial production of various enzymes in the country. The production of recombinant proteins through strain engineering is one of the most important ways to meet this demand due to its many benefits. One of the most important microorganisms that is widely used in the enzyme industry is Bacillus subtilis. Due to its thick peptidoglycan wall, this gram-positive bacterium hardly accepts engineered carriers for genetic modification as hosts. The aim of this study was to evaluate the permeability of the wall and cell membrane of Bacillus subtilis... 

    Improvement to speech-music discrimination using sinusoidal model based features

    , Article Multimedia Tools and Applications ; Volume 50, Issue 2 , November , 2010 , Pages 415-435 ; 13807501 (ISSN) Shirazi, J ; Ghaemmaghami, S ; Sharif University of Technology
    2010
    Abstract
    This paper addresses a model-based audio content analysis for classification of speech-music mixed audio signals into speech and music. A set of new features is presented and evaluated based on sinusoidal modeling of audio signals. The new feature set, including variance of the birth frequencies and duration of the longest frequency track in sinusoidal model, as a measure of the harmony and signal continuity, is introduced and discussed in detail. These features are used and compared to typical features as inputs to an audio classifier. Performance of these sinusoidal model features is evaluated through classification of audio into speech and music using both the GMM (Gaussian Mixture Model)... 

    Audio classification based on sinusoidal model: a new feature

    , Article 2008 IEEE Region 10 Conference, TENCON 2008, Hyderabad, 19 November 2008 through 21 November 2008 ; 2008 ; 1424424089 (ISBN); 9781424424085 (ISBN) Shirazi, J ; Ghaemmaghami, S ; Sharif University of Technology
    2008
    Abstract
    In this paper, a new feature set is presented and evaluated based on sinusoidal modeling of audio signals. Duration of the longest sinusoidal model frequency track, as a measure of the harmony, is used and compared to typical features as input into an audio classifier. The performance of this sinusoidal model feature is evaluated through classification of audio to speech and music using both the GMM and the SVM classifiers. Classification results show the proposed feature, which could be used for the first time in such an audio classification, is quite successful in speech/music classification. Experimental comparisons with popular features for audio classification, such as HZCRR and LSTER,... 

    Solving the minimum toll revenue problem in real transportation networks

    , Article Optimization Letters ; 2014 ; ISSN: 18624472 Shirazi, M ; Aashtiani, H. Z ; Sharif University of Technology
    2014
    Abstract
    As a means to relieve traffic congestion, toll pricing has recently received significant attention by transportation planners. Inappropriate use of transportation networks is one of the major causes of network congestion. Toll pricing is a method of traffic management in which traffic flow is guided to proper time and path in order to reduce the total delay in the network. This article investigates a method for solving the minimum toll revenue problem in real and large-scale transportation networks. The objective of this problem is to find link tolls that simultaneously cause users to efficiently use the transportation network and to minimize the total toll revenues to be collected. Although... 

    Parametric study and computation of seismic performance factors of braced shear panels

    , Article Scientia Iranica ; Volume 23, Issue 2 , 2016 , Pages 460-474 ; 10263098 (ISSN) Hamed, A ; Mofid, M ; Sharif University of Technology
    Sharif University of Technology  2016
    Abstract
    By locating a steel shear panel on the intersection point of the X-braces, concentrically or eccentrically braced shear panel (CBFSP or EBFSP) is formed. In this paper, to perform parametric study, 1-story CBFSP and EBFSP models with span length greater or less than height are considered. Using linear static analyses, the effects of size and location of the shear panel on the lateral stiffness of the frame with respect to the moment resisting frame with the same member sections are investigated. Next, for 1- And 3-story models, maximum displacement, along with base shear, and the ratio between the dissipated energy and input energy are examined under 4 ground motion records. Behavior of the... 

    Assessment of Seismic Retrofit Policies for Buildings

    , M.Sc. Thesis Sharif University of Technology Movahedi, Ali (Author) ; Kashani, Hamed (Supervisor)
    Abstract
    Occurrence of natural disasters such as earthquake could seriously damage most buildings especially those with insufficient resistance located in urban worn-out textures. In order to reduce unpleasant consequences of an earthquake, appropriate policies need to be considered to persuade the beneficiaries to follow retrofitting standards in the process of planning, designing, and construction of buildings. These policies shall be implemented through institutions in arbitrary or obligatory forms, by encouragement or penalty mechanisms. In order to consider these policies, first of all we need to identify the beneficiaries and their particulars. By studying and considering subjects discussed in... 

    Optimal-Robust Control of Drug Delivery in Cancer Chemotherapy

    , M.Sc. Thesis Sharif University of Technology Hosseini, Fatemeh (Author) ; Moradi, Hamed (Supervisor)
    Abstract
    Chemotherapy is a proven and effective systematic approach to treat various types of cancers. Despite its advantages, chemotherapy would kill healthy as well as cancer cells. To overcome this problem, different controlling strategies are implemented. This study aims to provide a medicine drug delivery schedule for chemotherapy (by designing a proper controlling system) based on the verifiable mathematical models. First, the dynamic model is analysed and stability points are reviewed. The selected model has five state variables and two inputs. In this study, the focus is on dynamic model analysis and obtaining an effective and appropriate treatment pattern by designing a proper controller. To... 

    Real Options Analysis Framework for the Optimal Timing of Network Infrastructure Systems Retrofits

    , M.Sc. Thesis Sharif University of Technology Roghani, Mehran (Author) ; Kashani, Hamed (Supervisor)
    Abstract
    Natural disasters can damage the infrastructure of society. Damages to the infrastructure components of society can disrupt their service delivery. Disruption in providing services to society's infrastructure can disrupt social and economic activities and impose various significant costs on society. The cost of repairing the damaged infrastructure and reducing the income of households are among the economic damages of accidents. The decline in the quality of life, as well as the death and injury of people due to the breakdown of the infrastructure or the disruption in their services, are among the social damages caused by accidents. In the same way, natural disasters are considered a... 

    Analysis of Seismic Vulnerability Reduction Policies of Residential Buildings Using a Multi-agent Evolutionary Game Model Based on Prospect Theory

    , M.Sc. Thesis Sharif University of Technology Hosseini, Ahmad (Author) ; Kashani, Hamed (Supervisor)
    Abstract
    Due to the vulnerability of urban fabric and residential buildings to earthquakes and considering its destructive social and economic effects on society, the need to adopt appropriate policies to prevent and reduce vulnerability, has been increasingly considered by policy makers. Despite the laws, regulations, incentives and penalties that policymakers have envisioned to prevent unprincipled and unsafe construction, evidence shows that a significant number of new buildings being built in the country are not earthquake resistant and there are many violations in design, implementation and supervision that is done by the stakeholders. To solve this problem, research has been done on the... 

    Development of a Multi-functional Soil Column for Studying Bioremediation and Multiphase Flow

    , M.Sc. Thesis Sharif University of Technology Samari, Peyman (Author) ; Sadeghi, Hamed (Supervisor)
    Abstract
    Soil and water pollution is one of the most common types of pollution in terrestrial and aquatic ecosystems. The development of mines and the oil and petrochemical industry on one hand and the non-compliance with environmental requirements on the other hand have caused large amounts of hydrocarbon pollutants and heavy metals to enter the environment in recent decades. Petroleum materials and heavy metals leak into the surrounding environment during drilling and extraction in oil sites and mines or during land and sea transportation, despite the measures taken to control their pollution. The conducted studies show that human industrial activities are the only cause of environmental pollution... 

    Developing Novel Algorithms to Simultaneous Power Regulation and Load Mitigation of Modern Variable Speed Wind Turbines

    , Ph.D. Dissertation Sharif University of Technology Golnary, Farshad (Author) ; Moradi, Hamed (Supervisor)
    Abstract
    The power control of horizontal axis wind turbines can affect significantly the vibration loads and fatigue life of the tower and the blades. In this thesis, we are going to consider both the power control and vibration load mitigation of the tower fore-aft vibration. For this purpose, at first, we developed a fully coupled model of the NREL 5MW turbine. This model considers the full aeroelastic behavior of the blades and tower and is validated by experiment results, comparing the time history data with the FAST (Fatigue, Aerodynamics, Structures, and Turbulence ) code which is developed by NREL (National Renewable Energy Lab in the United States). In the next, to estimate EWV, a novel... 

    Laboratory Investigation of the Effects of Sodium Chloride Concentration on Soil Water Retention Curve and Volumetric behavior Using an Unsaturated Automatic Oedometer

    , M.Sc. Thesis Sharif University of Technology Nasiri, Hamed (Author) ; Sadeghi, Hamed (Supervisor)
    Abstract
    Laboratory studies to investigate the effects of different saline concentrations (such as sodium chloride or calcium chloride) on the soil water retention behavior of clayey soils and their volumetric changes have received much attention recently. However, many previous studies have investigated these effects in only one path of the SWRC (wetting or drying path) and the effects of saline concentration on hydraulic hysteresis have not been considered. In addition, researchers have frequently studied these effects on SWRC on clay samples, and little research has been done on collapsible soils. Therefore, the most important purpose of this study is to investigate the effects of increasing... 

    Robust and Nonlinear Control of the Boiler-Turbine Unit Performance in a Coal Fired Ultra-Supercritical Once Through Boiler Power Plant in Order to Optimize the Uncertain Problem

    , M.Sc. Thesis Sharif University of Technology Esmaeili, Mohammad (Author) ; Moradi, Hamed (Supervisor)
    Abstract
    Nowadays electricity power has a key role in developing various aspects of the world. The great importance of fossil fuel power plants come from their large contribution in electricity power generation. Among the different fossil fuel power generation technologies, supercritical power plants have great advantages. They are an advanced power generation technology with high plant efficiency, high coal utilization and low emission. Their complexity and existing many unavoidable uncertainty sources in their dynamic such as changes of ambient temperature, climate condition and wear of components make their control challenging. To overcome mentioned problems and achieving a good performance, a...