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    Exposure Level of Vehicle Cabins to Particulate Matter and Gaseous Contaminations: Experimental Investigation and Theoretical Modeling of Influential Factors

    , M.Sc. Thesis Sharif University of Technology Saemian, Peyman (Author) ; Arhami, Mohammad (Supervisor)
    Abstract
    Mobile Sources are the main source of air pollutant emission in Tehran, the capital city of Iran. Everyday thousands of vehicles commute in roads and highways. Unfortunately, People are exposed to high level of particulate matter and gaseous contaminants in automobile cabins. Even though this environment is exposed to high pollutant concentration emitted by on-road vehicle, In comparison with other built environment, in-cabin commuter exposure and its key parameters has never been quantified. In general, this work entails measurement of in-cabin air quality, predicting mathematical models for calculating Air-Exchange-Rate (AER) in vehicles and on-road vehicle emission measurement. Our... 

    Strain Effect on the CO & H2 Adsorption Upon Graphene

    , M.Sc. Thesis Sharif University of Technology Bagheri, Beytolhoda (Author) ; Irajizad, Azam (Supervisor)
    Abstract
    In this thesis, adsorption of Carbon monoxide and Hydrogen on graphene, by DFT calculation has been studied. Also effect of strain on some electrical properties, such as band structure, electrical conductivity and Density of states, for pristine graphene and adsorption CO and H2 on it has been probed. This results show that with strain up to 12% on pristine graphene , we won’t have any band gap on Fermi surface and energy adsorption for Carbon monoxide on strained graphene (up 12%) increase up 400 per cent. Also for strained graphene (12%) on Carbon monoxide adsorption condition we will have energy band gap almost a few electron volt on Fermi surface. In general this results express... 

    Study of Carbon Monoxide Emission and Dispersion in Long Motorway Spaces: A Case Study of Tohid Tunnel

    , M.Sc. Thesis Sharif University of Technology Alizadeh Aliabadi, Hamzeh (Author) ; Vaziri, Manouchehr (Supervisor)
    Abstract
    Vehicular tunnels are very prone to excess of air pollution due to their enclosed nature. Inadequate ventilation combined with high traffic flow result in elevated concentration of vehicle-induced air pollutants, which can pose serious health hazards. This study was carried out in the longest vehicular tunnel in Tehran, locally referred to as Tohid tunnel. Traffic flow characteristics, carbon monoxide level and it's dispersion along the tunnel were investigated in this project. Data were collected in 4 days and 3 times a day, 7-8 in the morning, 11-12 and 17-18 in the evening. Measurements were conducted at fixed locations, outside the tunnel,... 

    Evaluating the Levels of Air Pollutants and Their Affecting Factors in Highways of Tehran

    , M.Sc. Thesis Sharif University of Technology Nayebyazdi, Mohammad (Author) ; Arhami, Mohammad (Supervisor)
    Abstract
    The concentration of air pollutants in the environment is variable according to different factors, including distances from main sources. Vehicles in streets and highways are one of the most important sources of the air pollutants. Hemmat highway is one of the most significant highways in Tehran with traffic congestion of 15000 to 18000 vehicle/hour. In this research, the concentrations of PM10 and CO were determined in different distances of Shahid Hemmat highway and the relationship diagrams of traffic and meteorology to the amount and emission of air pollutants were drawn. The concentration gradient diagrams showed exponential decay, which demonstrated that more than of 50% of air... 

    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... 

    Analysis of CO Distribution in Large Tunnel Fires

    , M.Sc. Thesis Sharif University of Technology Sojoudi, Atta (Author) ; Farhanieh, Bijan (Supervisor)
    Abstract
    Fire events and the related toxicants such as CO are responsible for many fatalities inthe current century. These hazardous events are more dangerous when they occur in enclosedspaces. In the present study, a theoretical relation is developed for horizontal distribution of COin a large tunnel fire. Then, developed criterion is used to study the effect of rudimentaryparameters such as Heat Release Rate (HRR) of fire and tunnel Aspect Ratio (AR) on CO andtemperature stratification. Theoretical results of various heat release rates and aspect ratios forhorizontal distribution of CO are compared with numerical results using Fire DynamicsSimulator (FDS5.5). It is found that big fires have higher... 

    Simulation of Hydrocarbon Waste-gas Combustion in Incinerator and Pollution Control

    , M.Sc. Thesis Sharif University of Technology Modarres, Mohammad Reza (Author) ; Darbandi, Masoud (Supervisor)
    Abstract
    Emission control, especially Carbon Monoxides (CO) as one of the major by-products of combustion processes, is one of the most serious challenges in burning waste-gases with high amounts of humidity and Carbon Monoxide. We investigated an oil waste-gas incinerator serving to a bitumen production line located in Pasargad Oil Company, Shazand, Arak, Iran. The aforementioned incinerator was criticized seriously for its high CO emissions. We were requested to find a solution to reduce the undesirable CO emission from that. Following the environmental standards, there is an upper limit of 150 ppm for the CO produced by an industrial waste oil incinerator. To present an inclusive solution for such... 

    Study of Tehran Air Pollutants Dispersion with CMAQ Modeling System

    , M.Sc. Thesis Sharif University of Technology Hashemian Nezhad, Babak (Author) ; Arhami, Mohammad (Supervisor)
    Abstract
    Tehran air quality is facing a real crisis. Reports of pertinent organizations show air quality is deteriorating in recent years and unhealthy days are increasing. As a result, study and planning in order to change this trend and moving toward improving air quality is a necessity. On the other hand, in order to make proper decisions and choosing effective approaches considering cost-effective attribute and legal, temporal and budget restrictions, selecting the right tool is essential. Air quality models are the tools which in a cost saving manner and reasonable time can provide the required results for researchers, decision makers and legislators. An applicable model correspondent with urban... 

    Study of Change of Thermochemical Properties of DNA bases in the Presence of Neutral, Anionic, and Radical Species

    , M.Sc. Thesis Sharif University of Technology Mottaghizadeh, Ayda (Author) ; Fattahi, Alireza (Supervisor)
    Abstract
    Since we are exposed to many air pollutants such as different gases daily, this project has attempted to investigate how these gases affect nucleobases, which are the main constituent of the DNA chain. The gases used in this study are sulfur dioxide (SO2), carbon monoxide (CO) and nitric oxide (NO). Each of these gases was studied separately along with the most stable nucleobase in the neutral, anionic and cationic states. The AT and GC base pairs were also exposed to each of these gases and changes (for exampl, the acidity, proton affinity) created in the AT and GC base pairs were examined.The most important properties studied during this project include gas-nucleobase interactions, proton... 

    Investigation of Performance and Improvement of the Activity of MOF-based Catalysts in CO Oxidation Reaction

    , Ph.D. Dissertation Sharif University of Technology Abbasi, Fatemeh (Author) ; Ghotbi, Cyrus (Supervisor) ; Karimi Sabet, Javad (Supervisor)
    Abstract
    Different catalysts have been proposed for CO oxidation reaction and still many researches are performed to obtain a catalyst with high activity and stability. In this study, MOFs of CuBTC, MIL-101(Cr), and NH2-MIL-101(Cr) and active metal of Pd have been selected and their performances have been investigated in CO oxidation reaction. MOFs have been synthesized by hydrothermal method. Pd loading has been performed by impregnation method in various pH and in aqeous palladium nitrate solution and palladium nitrate solution in nitric acid. To reveal the effect of the nature of noble metal, activity of 1% Pt/MIL has been investigated. Amine-functionalized MIL-101(Cr) has been synthesized by... 

    Exposure Level of Vehicle Cabins to Particulate Matter and Gaseous Contaminations: Experimental Investigation and Theoretical Modeling of Influential Factors

    , M.Sc. Thesis Sharif University of Technology Delavarrafiee, Maryam (Author) ; Arhami, Mohammad (Supervisor)
    Abstract
    Mobile Sources are the main source of air pollutant emission in Tehran, the capital city of Iran. Everyday thousands of vehicles commute in roads and highways. Unfortunately, People are exposed to high level of particulate matter and gaseous contaminants in automobile cabins. Even though this environment is exposed to high pollutant concentration emitted by on-road vehicle, In comparison with other built environment, in-cabin commuter exposure and its key parameters has never been quantified.
    In general, this work entails measurement of in-cabin air quality, predicting mathematical models for calculating Air-Exchange-Rate (AER) in vehicles and on-road vehicle emission measurement. Our... 

    Mathematical modeling of the reaction in an iron ore pellet using a mixture of hydrogen, water vapor, carbon monoxide and carbon dioxide: An isothermal study

    , Article Advanced Powder Technology ; Volume 17, Issue 3 , 2006 , Pages 277-295 ; 09218831 (ISSN) Valipour, M. S ; Motamed Hashemi, M. Y ; Saboohi, Y ; Sharif University of Technology
    VSP BV  2006
    Abstract
    A mathematical time-dependent and isothermal model based on the grain model has been developed to simulate the kinetic and thermal behaviors of a porous iron oxide pellet undergoing chemical reactions with a mixture of hydrogen, carbon monoxide, carbon dioxide and water vapor. Its novelty consists in fact that it can deal with a multi-species reducing gas and oxide pellet. In spite of previous models in which the pure reductant was applied as reducing gas, this model can indicate an actual view of pellet reduction including the effects of reducing gas utility and reducing gas ratio. A finite volume fully implicit technique was applied for solving the governing equations. The model has been... 

    Three-dimensional superconvergent patch recovery method and its application to data transferring in small-strain plasticity

    , Article Computational Mechanics ; Volume 41, Issue 2 , 2008 , Pages 293-312 ; 01787675 (ISSN) Gharehbaghi, S. A ; Khoei, A. R ; Sharif University of Technology
    Springer Verlag  2008
    Abstract
    In this paper, a 3D Superconvergent Patch Recovery (SPR) method is developed for data transferring in elasto-plasticity. The transfer operators are presented for mapping of the state and internal variables between different meshes. In order to transfer the history-dependent variables from old mesh to new one, the internal variables are firstly mapped from the Gauss points to nodal points of old mesh, the variables are then transferred from nodal points of old mesh to nodal points of new mesh, and the values are finally transferred from the nodal points to Gauss points of new mesh. As the solution procedure cannot be re-computed from the initial state, it is continued from the previously... 

    Numerical study on the effects of creating rotationary flow inside the injector nozzle and changing fuel injection angle on the performance and emission of caterpillar diesel engine

    , Article Journal of the Brazilian Society of Mechanical Sciences and Engineering ; Volume 44, Issue 1 , 2022 ; 16785878 (ISSN) Farajollahi, A. H ; Firuzi, R ; Rostami, M ; Mardani, A ; Sharif University of Technology
    Springer Science and Business Media Deutschland GmbH  2022
    Abstract
    One way of improving the performance of diesel engines is to produce modifications in the fuel supply systems. In this article, the effects of creating rotationary flow inside the nozzle and changing fuel injection angle on the performance and emission of caterpillar diesel engine have been examined in two separate stages using AVL FIRE software. First, the injector and its spray have been simulated with various geometries. The numerical results of this step indicate that creating rotationary flow inside the nozzle decreases the penetration length, while increases fuel spray cone angle and improves atomization quality. In the subsequent step, the diesel engine has been simulated with its... 

    Development of kinetic model for CO hydrogenation reaction over supported Fe-Co-Mn catalyst

    , Article New Journal of Chemistry ; Volume 41, Issue 18 , 2017 , Pages 10452-10466 ; 11440546 (ISSN) Arsalanfar, M ; Abdouss, M ; Mirzaei, N ; Zamani, Y ; Sharif University of Technology
    Royal Society of Chemistry  2017
    Abstract
    Kinetic modeling of CO hydrogenation over Fe-Co-Mn catalyst was investigated; a ternary catalyst was prepared using incipient wetness impregnation. The kinetic parameters were determined from experiments carried out in a fixed bed micro-reactor under the following process conditions: T = 523.15-533.15 K, P = 1-10 bar, H2/CO = 1/1-3/1 and space velocity = 4500 h-1. Seventeen rate expressions were derived from five different mechanisms according to Langmuir-Hinshelwood-Hougen-Watson (LHHW) and Eley-Rideal (ER) mechanisms and were tested against the experimental data. Non-linear regression method was used to estimate different kinetic parameters; according to the obtained experimental results... 

    Light olefin production on the Co-Ni catalyst: Calcination conditions, and modeling and optimization of the process conditions by a statistical method

    , Article New Journal of Chemistry ; Volume 44, Issue 18 , 2020 , Pages 7467-7483 Arsalanfar, M ; Akbari, M ; Mirzaei, N ; Abdouss, M ; Sharif University of Technology
    Royal Society of Chemistry  2020
    Abstract
    The present work is comprised of two main parts. In part 1 the Co-Ni/γ-Al2O3 catalyst was prepared using a sol-gel procedure. Then the effect of calcination variables including the calcination temperature and time on the catalytic performance for production of light olefins was investigated and optimized. The obtained results have shown that the catalyst which was calcined at 550 °C for 6 h has revealed the better catalytic performance for production of light olefins. In part 2 the effect of process conditions including the reaction temperature, H2/CO feed ratio and total reaction pressure on the catalytic performance (CO conversion%, (C2-C4) selectivity% and C5+ selectivity%) was... 

    Detailed analysis of the effects of biodiesel fraction increase on the combustion stability and characteristics of a reactivity‐ controlled compression ignition diesel‐biodiesel/natural gas engine

    , Article Energies ; Volume 15, Issue 3 , 2022 ; 19961073 (ISSN) Zarrinkolah, M. T ; Hosseini, V ; Sharif University of Technology
    MDPI  2022
    Abstract
    A single‐cylinder marine diesel engine was modified to be operated in reactivity controlled compression ignition (RCCI) combustion mode. The engine fueling system was upgraded to a common rail fuel injection system. Natural gas (NG) was used as port fuel injection, and a die-sel/sunflower methyl ester biodiesel mixture was used for direct fuel injection. The fraction of bio-diesel in the direct fuel injection was changed from 0% (B0; 0% biodiesel and 100% diesel) to 5% (B5) and 20% (B20) while keeping the total energy input into the engine constant. The objective was to understand the impacts of the increased biodiesel fraction on the combustion characteristics and stability, emissions, and... 

    Mössbauer and magnetic studies of iron-zeolite and iron-cobalt zeolite catalysts used in synthesis gas conversion

    , Article International Journal of Engineering, Transactions B: Applications ; Volume 20, Issue 3 , 2007 , Pages 263-274 ; 1728-144X (ISSN) Oskoie, M ; Lo, C ; Sharif University of Technology
    Materials and Energy Research Center  2007
    Abstract
    Medium-pore (diameter - 6A) zeolites such as ZSM-5 and silicalite impregnated with Group VIII metals provide selective catalytic pathways for the conversion of synthesis gas to gasoline or olefins. Mössbauer and magnetic studies on these catalysts containing iron or iron plus cobalt are reported. The zeolites were impregnated with metal nitrate solutions, reduced, and carbided to yield showed Fe3+ type spectra. The ZSM-5 (14.7 % Fe) and Silicalite (13.6 % Fe) samples exposed to H2 (450 C) showed an approximate 85% reduction to the metallic state. The carbided ZSM-5 (14.7 % Fe) revealed a spectrum of Hagg carbide (Fe5C2), an active component of the catalyst. The used catalysts showed mixtures... 

    Effect of reformer gas blending on homogeneous charge compression ignition combustion of primary reference fuels using multi zone model and semi detailed chemical-kinetic mechanism

    , Article Applied Energy ; Volume 179 , 2016 , Pages 463-478 ; 03062619 (ISSN) Neshat, E ; KhoshbakhtiSaraya Saray, R ; Hosseini, V ; Sharif University of Technology
    Elsevier Ltd  2016
    Abstract
    This study mainly aims to investigate the effect of reformer gas (RG) addition on the performance of homogeneous charge compression ignition (HCCI) engines using a multi zone model. The developed model is validated using a wide range of experimental data of a cooperative fuel research engine. Blended fuels of isooctane and n-heptane, known as primary reference fuels, with different octane numbers are used as the main engine fuel. A semi detailed chemical-kinetic mechanism containing 101 species and 594 reactions is used to simulate the combustion of blended fuels. The study is performed with different percentages of RG (0–30%). The results show that RG reduces the rate of some H abstraction... 

    Carbonaceous supports decorated with Pt–TiO2 nanoparticles using electrostatic self-assembly method as a highly visible-light active photocatalyst for CO2 photoreduction

    , Article Renewable Energy ; Volume 145 , January , 2020 , Pages 1862-1869 Larimi, A ; Khorasheh, F ; Sharif University of Technology
    Elsevier Ltd  2020
    Abstract
    Supported Pt–TiO₂ photocatalysts on carbonaceous supports were synthesized by the electrostatic self-assembly method to study CO₂ photoreduction to produce CH₄. Catalytic activities of the prepared photocatalysts were correlated with the particle size and dispersion of the active metal, which in turn depended on the type of carbonaceous support used, varying in the order of multi-walled carbon nanotubes (MWCNT) > Single-walled carbon nanotubes (SWCNT) > reduced graphene oxide > activated carbon. Generally, all catalysts were highly photoresistant with less than 5% loss of activity in terms of CH₄ yield. Pt–TiO₂/multi-walled carbon nanotubes exhibited better catalytic activity compared with...