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Total 36 records

    Water Quality Modeling of Urban Streams

    , M.Sc. Thesis Sharif University of Technology Soltani, Maryam (Author) ; Tajrishy, Masoud (Supervisor)
    Abstract
    With altering natural state and increasing impervious surfaces, traditional urbanization leads to deteriorating the environment and water catchments. During the years most efforts in order to control the urban runoff outflow, have been focused on quantity; and awareness about improving water quality has been raised just in the last few years and, which emphasizes on pollution source control. Standard water quality sampling methods are time consuming, expensive and because of sampling in broad geographic areas, difficult; however modeling is a more efficient way in assessing water quality and as worries about non-point source pollution grows, different kinds of models have been used to... 

    Improving Distribution System Resilience Using Microgrids

    , Ph.D. Dissertation Sharif University of Technology Bahrami, Mahdi (Author) ; Vakilian, Mehdi (Supervisor) ; Farzin, Hossein (Co-Supervisor) ; Lehtonen, Matti (Co-Supervisor)
    Abstract
    The number and severity of natural disasters have significantly increased in the recent years. Extreme weather-driven events cause catastrophic damages to power grid components. As a consequence, severe power outages occur in the affected grids. According to the published reports on natural disasters, 90 percent of such outages originate from distribution systems. In addition, the repair process of the damaged elements takes a long duration. Thus, it is necessary to improve the distribution system (DS) resilience against natural disasters. The strategies for resilience enhancement can be classified into two main groups: hardening and operation-oriented measures.Formation of microgrids has... 

    A stochastic framework for optimal island formation during two-phase natural disasters

    , Article IEEE Systems Journal ; 2021 ; 19328184 (ISSN) Bahrami, M ; Vakilian, M ; Farzin, H ; Lehtonen, M ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2021
    Abstract
    This article proposes a new three-stage stochastic framework for dealing with predictable two-phase natural disasters in distribution systems. This framework is a multiobjective optimization, in which the amount of curtailed energy, the number of switching actions, and the vulnerability of operational components are selected as the main criteria for decision-making process. The optimization problem is formulated in the form of a stochastic mixed-integer linear programming (MILP) problem. In this article, a windstorm event followed by flooding is analyzed as a two-phase natural disaster. In this regard, the uncertainties associated with gust-wind speed, floodwater depths, and load demands are... 

    A stochastic framework for optimal island formation during two-phase natural disasters

    , Article IEEE Systems Journal ; Volume 16, Issue 2 , 2022 , Pages 2090-2101 ; 19328184 (ISSN) Bahrami, M ; Vakilian, M ; Farzin, H ; Lehtonen, M ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2022
    Abstract
    This article proposes a new three-stage stochastic framework for dealing with predictable two-phase natural disasters in distribution systems. This framework is a multiobjective optimization, in which the amount of curtailed energy, the number of switching actions, and the vulnerability of operational components are selected as the main criteria for decision-making process. The optimization problem is formulated in the form of a stochastic mixed-integer linear programming (MILP) problem. In this article, a windstorm event followed by flooding is analyzed as a two-phase natural disaster. In this regard, the uncertainties associated with gust-wind speed, floodwater depths, and load demands are... 

    Characterization of ionic composition of TSP and PM10 during the Middle Eastern Dust (MED) storms in Ahvaz, Iran

    , Article Environmental Monitoring and Assessment ; Volume 184, Issue 11 , November , 2012 , Pages 6683-6692 ; 01676369 (ISSN) Shahsavani, A ; Naddafi, K ; Jaafarzadeh Haghighifard, N ; Mesdaghinia, A ; Yunesian, M ; Nabizadeh, R ; Arhami, M ; Yarahmadi, M ; Sowlat, M. H ; Ghani, M ; Jonidi Jafari, A ; Alimohamadi, M ; Motevalian, S. A ; Soleimani, Z ; Sharif University of Technology
    2012
    Abstract
    Because of the recent frequent observations of major dust storms in southwestern cities in Iran such as Ahvaz, and the importance of the ionic composition of particulate matters regarding their health effects, source apportionment, etc., the present work was conducted aiming at characterizing the ionic composition of total suspended particles (TSP) and particles on the order of ∼10 μm or less (PM10) during dust storms in Ahvaz in April-September 2010. TSP and PM10 samples were collected and their ionic compositions were determined using an ion chromatography. Mean concentrations of TSP and PM10 were 1,481.5 and 1,072.9 μg/m 3, respectively. Particle concentrations during the Middle Eastern... 

    Using FPGA as Accelerator for Processing Units in Big Data Stream Processing Engine

    , M.Sc. Thesis Sharif University of Technology Darjani, Armin (Author) ; Goudarzi, Maziar (Supervisor)
    Abstract
    Distributed stream processing frameworks (DSPFs) are used for real-time processing of big data. Apache Storm is one of the most popular stream processing systems in industry today. By increasing data generation rate we need new methods to overcome processing requirements of DSPFs like Apache Storm. In this thesis we investigate the feasibility of incorporation FPGA acceleration into Apache Storm. Using FPGAs as co-processors in powerful servers can improve performance and accelerate processing of streaming data by increasing parallelism, decreasing processing time of each processing units and decreasing communication delay between these units. Our design includes a hardware part that... 

    Modeling and Forecasting Dust Storms in Yazd Province

    , Ph.D. Dissertation Sharif University of Technology Hosseini Dehshiri, Shahabaddin (Author) ; Firoozabadi, Bahar (Supervisor) ; Afshin, Hossein (Co-Supervisor)
    Abstract
    The Yazd province is located in the dry and desert region of Iran and is constantly exposed to strong winds and dust storms due to its climatic conditions and geographical location. The first objective of this thesis is to assess the dust storm events that have occurred in Yazd province in order to identify their source and pathways of transport during the long-term period of 2012-2019. A novel multi-criteria framework for identifying the sources of dust storms and dust events in Yazd province has been presented using the HYSPLIT model. In this framework, the numerical results, along with geographical features, observational and satellite data, were used as criteria in the multi-criteria... 

    Contribution of the Middle Eastern dust source areas to PM10 levels in urban receptors: Case study of Tehran, Iran

    , Article Atmospheric Environment ; Volume 75 , 2013 , Pages 287-295 ; 13522310 (ISSN) Givehchi, R ; Arhami, M ; Tajrishy, M ; Sharif University of Technology
    2013
    Abstract
    The origins and evolution of the Middle Eastern dust storms which frequently impact the residents of this arid region were studied. A methodology was adapted and developed to identify the desert regions of potential dust sources and determine their contributions to PM10 concentrations in the highly-populated receptor city of Tehran, Iran. Initially, the episodes of regional dust intrusion and the resulting amounts of increase in the particulate concentrations during these episodes were determined using a statistical analyzing methodology. The dust episodes were also inspected with the aerosol index information from the Ozone Monitoring Instrument (OMI). The Hybrid Single-Particle Lagrangian... 

    Evaluation of permeable pavement responses to urban surface runoff

    , Article Journal of Environmental Management ; Volume 187 , 2017 , Pages 43-53 ; 03014797 (ISSN) Kamali, M ; Delkash, M ; Tajrishy, M ; Sharif University of Technology
    Academic Press  2017
    Abstract
    The construction of permeable pavement (PP) in sidewalks of urban areas is an alternative low impact development (LID) to control stormwater runoff volume and consequently decrease the discharge of pollutants in receiving water bodies. In this paper, some laboratory experiments were performed to evaluate the efficiency of a PP subjected to sediment loadings during its life span. Simple infiltration models were validated by the laboratory experiments to evaluate the trend and extend of PP infiltration capacity throughout the life of the pavement operation. In addition, performances of the PP in removing total suspended solids (TSS) and selective nutrient pollutants such as NO3 −, NH4 + and... 

    Dust concentration over a semi-arid region: parametric study and establishment of new empirical models

    , Article Atmospheric Research ; Volume 243 , 1 October , 2020 Najafpour, N ; Afshin, H ; Firoozabadi, B ; Sharif University of Technology
    Elsevier Ltd  2020
    Abstract
    In recent years, the city of Tehran, Iran's capital, has encountered numerous dust events so that the dust concentration of PM10 has reached even more than 800 μg m−3. This emphasizes the importance of the statistical study of dust in Tehran and the development of correlations for estimating dust concentration of PM10. In the present study, by evaluating the data measured during dust observations over the years 2013–2016 in Tehran, new statistical models are established for estimating PM10 concentration in terms of horizontal visibility and MODIS AOD. Firstly, simple nonlinear regression models between dust concentration of PM10 and horizontal visibility as well as MODIS AOD are developed.... 

    Energy storage planning for enhanced resilience of power distribution networks against earthquakes

    , Article IEEE Transactions on Sustainable Energy ; Volume 11, Issue 2 , 2020 , Pages 795-806 Nazemi, M ; Moeini Aghtaie, M ; Fotuhi Firuzabad, M ; Dehghanian, P ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2020
    Abstract
    Energy infrastructures are perceived continuously vulnerable to a range of high-impact low-probability (HILP) incidents - e.g., earthquakes, tsunamis, floods, windstorms, etc. - the resilience to which is highly on demand. Specifically suited to battery energy storage system (BESS) solutions, this paper presents a new resilience-driven framework for hardening power distribution systems against earthquakes. The concept of fragility curve is applied to characterize an earthquake hazard, assess its impact on power distribution systems, and estimate the unavailability of the network elements when exposed to extreme earthquakes. A new metric is defined to quantify the network resilience taking... 

    The application of multi-criteria (AHP-PROMETHEE) decision-making methods in selecting and prioritizing the green area irrigation resources

    , Article International Journal of Environmental Science and Technology ; 2020 Safari, A ; Abbaspour, M ; Javid, A. H ; Sharif University of Technology
    Springer  2020
    Abstract
    One of the underlying factors in the conservation and development of urban green spaces is the available water resources use for green areas in each region. The primary purpose of this study is to introduce the integration of a proper simulation method for runoff along with AHP-PROMETHEE decision-making method for water resources management in urban basins. The application of this approach was investigated in the city Buin Zahra of Qazvin Province of Iran. In the first step by using the analytic hierarchy process (AHP), the available water resources in the case study were weighted. In the second step, the water resources of the municipal and residential wells and water collected by... 

    The application of multi-criteria (AHP-PROMETHEE) decision-making methods in selecting and prioritizing the green area irrigation resources

    , Article International Journal of Environmental Science and Technology ; Volume 18, Issue 5 , 2021 , Pages 1135-1146 ; 17351472 (ISSN) Safari, A ; Abbaspour, M ; Javid, A. H ; Sharif University of Technology
    Springer Science and Business Media Deutschland GmbH  2021
    Abstract
    One of the underlying factors in the conservation and development of urban green spaces is the available water resources use for green areas in each region. The primary purpose of this study is to introduce the integration of a proper simulation method for runoff along with AHP-PROMETHEE decision-making method for water resources management in urban basins. The application of this approach was investigated in the city Buin Zahra of Qazvin Province of Iran. In the first step by using the analytic hierarchy process (AHP), the available water resources in the case study were weighted. In the second step, the water resources of the municipal and residential wells and water collected by... 

    A risk-based resilient distribution system planning model against extreme weather events

    , Article IET Renewable Power Generation ; Volume 16, Issue 10 , 2022 , Pages 2125-2135 ; 17521416 (ISSN) Zare Bahramabadi, M ; Ehsan, M ; Farzin, H ; Sharif University of Technology
    John Wiley and Sons Inc  2022
    Abstract
    Due to the accelerated climate change, it is anticipated that the number and severity of natural disasters such as hurricanes, blizzards, and floods will be increased in the coming years. In this regard, this paper presents a distribution system planning model to improve the system resilience against hurricane. A scenario-based mathematical model is proposed to capture the random nature of weather events. Moreover, a stochastic optimization model is developed to simultaneously harden the distribution lines and place different types of distributed generation (DG) units such as microturbines (MTs), wind turbines (WTs), and photovoltaic cells (PVs). The conditional value at risk (CVaR) is used... 

    A novel pre-storm island formation framework to improve distribution system resilience considering tree-caused failures

    , Article IEEE Access ; Volume 10 , 2022 , Pages 60707-60724 ; 21693536 (ISSN) Bahrami, M ; Vakilian, M ; Farzin, H ; Lehtonen, M ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2022
    Abstract
    This paper presents a new framework for island formation prior to windstorms, which considers tree-caused failures of distribution networks. In the proposed framework, both direct and indirect effects of windstorms on distribution lines are quantified. Thus, a novel discrete Markov chain model is proposed for representing the failure modes of trees in each time interval of windstorm duration. This model categorizes 'healthy', 'uprooted', 'stem breakage', and 'branch breakage' states of a tree. In addition, a new line-tree interaction model is presented for calculating tree-caused failure probability of overhead lines. The results of the proposed Markov model are taken as inputs by the... 

    A new application of multi-criteria decision making in identifying critical dust sources and comparing three common receptor-based models

    , Article Science of the Total Environment ; Volume 808 , 2022 ; 00489697 (ISSN) Hosseini Dehshiri, S. S ; Firoozabadi, B ; Afshin, H ; Sharif University of Technology
    Elsevier B.V  2022
    Abstract
    Dust storms are a common phenomenon in arid and semi-arid regions in West Asia, which has led to high levels of PM10 in local and remote area. The Yazd city in Iran with a high PM10 level located downstream of dust sources in the Middle East and Central Asia. In this study, based on meteorological and PM10 monitoring data, backward trajectory modeling of air parcels related to dust events at Yazd station was performed using the HYSPLIT model in 2012–2019. The trajectory cluster analysis was used to identify the main dust transport pathways and wind systems. Three methods of Cross-referencing Backward Trajectory (CBT), Potential Source Contribution Function (PSCF) and Concentration Weighted...