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    A novel viewpoint to the green city concept based on vegetation area changes and contributions to healthy days: a case study of Mashhad, Iran

    , Article Environmental Science and Pollution Research ; 2021 ; 09441344 (ISSN) Nejatian, A ; Makian, M ; Gheibi, M ; Fathollahi Fard, A. M ; Sharif University of Technology
    Springer Science and Business Media Deutschland GmbH  2021
    One of the significant challenges in urbanization is the air pollution. This highlights the need of the green city concept with reconsideration of houses, factories, and traffic in a green viewpoint. The literature review confirms that this reconsideration for green space has a positive effect on the air quality of large cities and to reduce the air pollution. The purpose of this study is to evaluate the annual vegetation changes in the green space of Mashhad, Iran as a very populated city in the middle east to study the air pollution. To investigate the relationship between the air pollution and vegetation, the Landsat 8 satellite images for summer seasons of 2013–2019 were used to extract... 

    Effect of Submerged Flexible Vegetation on Vertical Mixing Coefficient

    , M.Sc. Thesis Sharif University of Technology Taheri Paqale, Ahmad (Author) ; Jamali, Mir Mosadegh (Supervisor)
    Environmental flows are seldom independent of plants impact. Aquatic canopies are mostly submerged and flexible; this causes a significant impact on Hydrodynamics of flow and mixing structure. Experimental and analytical investigation of vertical mixing in vegetation canopies with flexible submerged vegetation is the aim of this study. Most of the previous studies on flexible submerged vegetation were conducted to study the transverse and longitudinal mixing. In this study, flexible submerged vegetation in the density range of 2.8% to 4.2% was used to study the vertical mixing.The concentration profiles at four separate stations were obtained by image processing. The results for the... 

    A numerical investigation of reactive air pollutant dispersion in urban street canyons with tree planting

    , Article Atmospheric Pollution Research ; Volume 8, Issue 2 , 2017 , Pages 253-266 ; 13091042 (ISSN) Moradpour, M ; Afshin, H ; Farhanieh, B ; Sharif University of Technology
    Elsevier B.V  2017
    Vegetation acts as a momentum and thermal sink, affecting the mixing of species and temperature-dependent constants of reaction rates. Numerical simulations were performed to investigate the effects of vegetation on the dispersion of reactive pollutants using a computational fluid dynamic (CFD) model coupled with NO-NO2-O3 photochemistry. Moreover, characteristics of temperature and flow fields were analyzed for different aspect ratios and leaf area densities. The results showed that flow is reversed in the presence of trees, and it enhances as leaf area density (LAD) increases; additionally, vegetation creates downward and vortex flows. The results also revealed that the dispersion of... 

    Nationwide prediction of drought conditions in Iran based on remote sensing data

    , Article IEEE Transactions on Computers ; Vol. 63, issue. 1 , Jan , 2014 , p. 90-101 ; 0018-9340 Jalili, M ; Gharibshah, J ; Ghavami, S. M ; Beheshtifar, M ; Farshi, R ; Sharif University of Technology
    Iran is a country in a dry part of the world and extensively suffers from drought. Drought is a natural, temporary, and iterative phenomenon that is caused by shortage in rainfall, which affects people's health and well-being adversely as well as impacting the society's economy and politics with far-reaching consequences. Information on intensity, duration, and spatial coverage of drought can help decision makers to reduce the vulnerability of the drought-affected areas, and therefore, lessen the risks associated with drought episodes. One of the major challenges of modeling drought (and short-term forecasting) in Iran is unavailability of long-term meteorological data for many parts of the... 

    The Study of Currents Caused by the Sunlight in Coastal Areas with Submerged and Emergent Vegetation

    , M.Sc. Thesis Sharif University of Technology Mousazadeh Darzi, Fatereh (Author) ; Jamali, Mirmosadegh (Supervisor)
    Aqueous environment with vegetation in coastal areas plays important role in ecologic systems. The plants in aqueous environment caused to vertical and lateral changes of flow velocity profile. When sunlight penetrates the water, it will turns into heat energy. The plants caused to blocking the light path, to make a difference in temperature and thus the density differences on the horizon. This density gradient will lead to the gravity flow. Due to the observations, in coastal wetlands, beside the plants the emerged from the water, there are some completely submerged plants that their root in the soil and shallow layer of fluid covered on them. This study to approaching the conditions, is... 

    , M.Sc. Thesis Sharif University of Technology Davari, Hoda (Author) ; Jamali, Mirmossadegh (Supervisor)
    Preservation and survival of ecological systems by vegetation is important. A study focusing on the hydrodynamics of these complex ecosystems could help to explain the filtering ability of vegetation in wetlands and estuaries. Wetlands assist in flood control, shoreline protection, and groundwater recharge. In addition, they play a purification role in removing sediments and contaminants from polluted waters, nutrient uptake, and oxygen production.
    Laboratory experiments have been designed to study the influence of marsh vegetation on lateral dispersion in flexible vegetation that has been modelled with inclined cylinder. The flow through vegetation is modelled by a circulating flow... 

    Lateral dispersion in deflected emergent aquatic canopies

    , Article Environmental Fluid Mechanics ; Volume 19, Issue 4 , 2019 , Pages 833-850 ; 15677419 (ISSN) Jamali, M ; Davari, H ; Shoaei, F ; Sharif University of Technology
    Springer Netherlands  2019
    Understanding the mechanism of dispersion within plants is essential for proper operation of natural and constructed treatment wetlands. Plant deflection induced by the current drag modifies the flow and dispersion within an aquatic canopy. In this study, we look at the effect of the deflection angle of the plants on transverse dispersion. Experiments were carried out in a current flume on an array of inclined solid rods representing a deflected emergent canopy. The stem Reynolds number varied between 90 and 360, normalized stem densities between 0.011 and 0.033, and the inclination angles between 0° and 45°. The plume development was recorded using image processing technique. A special... 

    A multi-objective analysis for import quota policy making in a perishable fruit and vegetable supply chain: A system dynamics approach

    , Article Computers and Electronics in Agriculture ; Volume 93 , 2013 , Pages 37-45 ; 01681699 (ISSN) Teimoury, E ; Nedaei, H ; Ansari, S ; Sabbaghi, M ; Sharif University of Technology
    This study investigates a supply chain of perishable fruits and vegetables. A simulation model using system dynamics approach is proposed to study the behaviors and relationships within the supply chain and to determine the impact of the supply, demand and price interactions. The proposed model yields an insight into the overall agricultural system, taking into account the influence of import quota policies. The purpose of this study is to develop a multi-objective model identifying the best import quota policy for Tehran Municipality Organization of Fruits and Vegetables. The multiple objectives are considered to be price mean, price variation and markup. Key conclusions were reached on how... 

    An investigation into the effects of green space on air quality of an urban area using CFD modeling

    , Article Urban Climate ; Volume 34 , December , 2020 Moradpour, M ; Hosseini, V ; Sharif University of Technology
    Elsevier B.V  2020
    Tehran, the capital of Iran, is one of the most polluted cities in the Middle East. However, there is no clear evidence of the effects of Tehran green spaces on reducing air pollution because there are still challenges to application of vegetation for improving air quality. The current study investigates the effects of a large volume of green space with 275 ha area in the vicinity of major highways on nearby air quality. Similar environments are often seen in many cities around the world. A computational fluid dynamics model containing aerodynamics and deposition effects of vegetation was used to simulate pollutant dispersion for eight wind directions and three different foliage densities.... 

    Evaluation of SMAP/Sentinel 1 high-resolution soil moisture data to detect irrigation over agricultural domain

    , Article IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing ; Volume 14 , 2021 , Pages 10733-10747 ; 19391404 (ISSN) Jalilvand, E ; Abolafia Rosenzweig, R ; Tajrishy, M ; Das, N ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2021
    Irrigation is not well represented in land surface, hydrological, and climate models. One way to account for irrigation is by assimilating satellite soil moisture data that contains irrigation signal with land surface models. In this study, the irrigation detection ability of SMAP enhanced 9 km and SMAP-Sentinel 1 (SMAP-S1), 3 km and 1 km soil moisture products are evaluated using the first moment (mean) and the second moment (variability) of soil moisture data. The SMAP enhanced 9 km soil moisture product lacks irrigation signals in an irrigated plain south of Urmia Lake, whereas SMAP-S1 products record irrigation signal in soil moisture variability. Despite observing higher variability... 

    Experimental Investigation of the Effect of Vertical Variation of Stem Density on Flow and Vertical Transport

    , M.Sc. Thesis Sharif University of Technology Ghazvinizadeh Esfahani, Somayeh (Author) ; Jamali, Mirmosaddegh (Supervisor)
    Presence of emergent vegetation can change the governing forces in flow through such systems and affects the turbulence structure and scalar transport. On the other hand, vertical variation of physical characteristics of stems, which is fairly observed in reality, leads to variation in frontal area and the called vertical density difference. In this study we experimentally investigate the effect of vertical density difference on both flow and vertical transport of mass. The results will be compared with theoretical predictions.
    Using rigid emergent model of cylinders as stems with step density variation in depth I simmulate field conditions considering actual variation of frontal area.... 

    Theoretical and Experimental Assessment of Exchange Flow Between Canopy and Open Area

    , M.Sc. Thesis Sharif University of Technology Marvi, Samaneh (Author) ; Jamali, Mirmosaddegh (Supervisor)
    Wetlands and aquatic systems are abundant on the earth. Since many biological and chemical processes take place in aquatic regions, an understanding of hydrodynamics of flow in these areas is essential. Exchange flows or gravity currents driven by horizontal density gradients constitute a significant transfer mechanism in many lentic systems. Light blockage by emergent vegetations, which are a common feature of littoral zones, leads to a horizontal density gradient and hence an exchange flow between the vegetated and the open area. Also, existence of vegetations affects the behavior of the flow by inserting the drag force to the system and damping its energy. Previous studies have modeled... 

    Exchange Flow Through Emergent Non-homogenous Canopy

    , M.Sc. Thesis Sharif University of Technology Rahnamyie Zekavat, Payam (Author) ; Jamali, Mirmosadegh (Supervisor)
    Numerical and laboratory models were used to investigate gravity exchange flow caused by spatial heterogeneity in water temperature, through emergent vegetation with varying diameter along their height (denoted by the parameter ) causing varying stem frontal area along vertical axis. Numerical model was used to anticipate flow characteristics and their alterations relative to non-dimensional vegetation diameter ratio. A set of Teflon dowels with various heights was used to simulate considered vegetative cross-section changes along vertical axis. Interface profile, toe velocity and flow rate were studied. Interface height and flow rate were inquired near the gate where expected to be... 

    Performance Reviews of Tehran’s Native Vegetative Filter Strips for Designing for the Removal of Pollutants of Surface Runoff

    , M.Sc. Thesis Sharif University of Technology Ghanbari Adivi, Mohammad (Author) ; Agha Mohammad Hossein Tajrishi, Massoud (Supervisor)
    Structural best management practices (BMPs) are often used to mitigate the impact of storm water runoff on receiving waters. Vegetative filter strips (VFS) are an example of a structural BMP that has been used to treat storm water and highway runoff. In this study (the first in Iran), field-quality data were collected from a native VFS treating urban runoff in North of Tehran. At first field data were used to test the design concepts of the VFS treatment train and to modify and calibrate simulation model for evaluating the impact of physical factors such as slope, type of vegetation and impermeable surface on sediment removal then more field data were used to evaluate and modify the... 

    Effect of Flexible Vegetation and their Variation Density Through Water Depth on Vertical Diffusion

    , M.Sc. Thesis Sharif University of Technology Sahebi, Reza (Author) ; Jamali, Mirmosadegh (Supervisor)
    Nowadays, vegetations have an important role in protecting ecological systems. One of the impacts of vegetation in water system is pollution diffusion. The physical characteristics of plants, affect how vegetation influence the diffusion phenomenon. Plants’ flexibility may change the drag force and pollution diffusion. Also density variations of vegetation in depths have important affects on flow characteristics.
    In this study we investigate experimentally the affects of flexible vegetations and their density changes in depths on vertical mass transport. Thus the current flume has modeled for crossing flow through the plants. To model the steep plants, inclined rigid cylinders have been... 

    Numerical Model for Slope Stability Assessment with Considering Hydrological Processes & Vegetation Influences

    , M.Sc. Thesis Sharif University of Technology Hajializadeh, Donya (Author) ; Ashtiyani Attayi, Behzad (Supervisor)
    Landslides are one of the most serious natural hazards in terms of victims and economic impact. This instability not only causes direct loss and causality but also intensifies instability’s compensation because of casualty in major transportation systems such as highway networks and connection networks such as electrical wires. Iran with mountainous nature and seismically active areas provides potential for broad instability. Thus determining the treatment of slope in response of time and different condition has significant inportance. The essential analysis for controlling instability is analysis of the slope resistance which results safety factor. This analysis is for assessment of... 

    Use of modified bentonite for phenolic adsorption in treatment of olive oil mill wastewater

    , Article Iranian Journal of Science and Technology, Transaction B: Engineering ; Volume 30, Issue 5 , 2006 , Pages 613-619 ; 03601307 (ISSN) Mousavi, S. M ; Alemzadeh, I ; Vossoughi, M ; Sharif University of Technology
    Natural and modified clays were applied as adsorbents for the removal of organic contaminants from wastewater. This study presents an investigation on the technical feasibility of using modified minerals that are named organoclay for treatment of dissolved substances, mainly polyphenols in olive mill wastewater. The different parameters such as applied cation dosage were effective on the removal of contaminants by these adsorbents (%CEC), pollutant concentration, pH and particle size of minerals. In this investigation bentonite particles were modified by stirring the clay with a long chain quaternary ammonium cation. Doses of the applied cation varied from zero to 1.5 times the clay CEC.... 

    Anaerobic digestion of vegetable waste

    , Article Chemical Engineering Transactions ; Volume 24 , 2011 , Pages 1291-1296 ; 19749791 (ISSN) Babaee, A ; Shayegan, J ; Sharif University of Technology
    Italian Association of Chemical Engineering - AIDIC  2011
    Fruit and vegetable wastes are produced in large quantities in Iran, and constitute a source of nuisance in municipal landfills. The objective of this study was to optimize the applications of anaerobic digestion for the treatment of municipal organic wastes. We studied the effect of organic loading rates on anaerobic digestion of vegetable wastes. The complete-mix, pilot-scale digester with working volume of 70 1 was used. The experiments were conducted at 34°C with a fixed hydraulic retention time of 25 days. The digester was operated at different organic feeding rates of 1.4, 2 and 2.75 kg VS/(m3.d). The biogas produced had methane composition of 49.7- 64% and biogas production rates of... 

    Thermally Driven Exchange Flow Between Open Water and Floating Vegetation

    , M.Sc. Thesis Sharif University of Technology Sharifi, Elham (Author) ; Jamali, Mirmosadegh (Supervisor)
    In this thesis, we present the results of a laboratory and numerical model study of the exchange flow generated by the temperature gradient between an open water heated by sunlight and a canopy area made of floating vegetation. Particle Image Velocimetry is employed to obtain the structures of the warm flow intruding the canopy at the surface and the bottom cold return flow for different roots length and vegetation density. Following an initial, transient stage of flow build-up governed by a balance between inertia and buoyancy forces, the flow reaches a steady state in the canopy area with a force balance between buoyancy and vegetation drag dominating the flow within roots. At the steady... 

    The Experimental Investigation of Lateral Dispersion In Vegetated Flow

    , M.Sc. Thesis Sharif University of Technology Shoaei, Farrokh (Author) ; Jamali, Mirmosadegh (Supervisor)
    There is an importance issue for preservation and survival of ecological systems by vegetation. A study focusing on the hydrodynamics of these complex ecosystems could help to explain the filtering ability of vegetation in wetlands and estuaries. Wetlands assist in flood control, shoreline protection, and groundwater recharge.In addition, they play a purification role, removing sediments and contaminants from polluted waters, nutrient uptake, and oxygen production. Laboratory experiments have been designed to study the influence of marsh vegetation on lateral dispersion. The flow through vegetation is modeled by a circulating flow going through an array of plastic dowels in an experimental...