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    Modeling of pressure line behavior of a common rail diesel engine due to injection and fuel variation

    , Article Journal of the Brazilian Society of Mechanical Sciences and Engineering ; Volume 39, Issue 3 , 2017 , Pages 661-669 ; 16785878 (ISSN) Mohebbi, M ; Aziz, A. A ; Hamidi, A ; Hajialimohammadi, A ; Hosseini, V ; Sharif University of Technology
    Springer Verlag  2017
    Common rail diesel engines with electronic fuel injection can accurately meter the fuel injection quantity with more accurate fuel injection control capability. In this work a common rail fuel injection system of a single cylinder diesel engine has been proposed and the important parameters like injection pressure, energizing time and high pressure pipes diameter and length are designed such that to be compatible with the engine basic design in case of pressure waves and injected mass variations. A one-dimensional approach has been used to model the injector using AMESim code in which Adiabatic models have been used to model injector system. Injected mass quantity has been calculated for... 

    The effect of diethyl ether addition on performance and emission of a reactivity controlled compression ignition engine fueled with ethanol and diesel

    , Article Energy Conversion and Management ; Volume 174 , 2018 , Pages 779-792 ; 01968904 (ISSN) Mohebbi, M ; Reyhanian, M ; Hosseini, V ; Said, M. F. M ; Abdul Aziz, A ; Sharif University of Technology
    Elsevier Ltd  2018
    Reactivity controlled compression ignition has been introduced to implement controllable, clean, and high thermal efficiency without undermining the advantages of premixed combustion. However, simultaneous auto-ignition introduced by reactivity controlled combustion challenges the combustion under higher load operations. This experimental study incorporates a dual phase heat release concept with the purpose of improving the performance of reactivity controlled compression ignition engine. Different ratios of ethanol/diethyl-ether blends (from 0% to 40% diethyl ether and 70% premixed ratio) were applied to a light duty diesel engine at various combustion timings and engine loads. The diesel... 

    Availability analysis on combustion of n-heptane and isooctane blends in a reactivity controlled compression ignition engine

    , Article Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering ; Volume 232, Issue 11 , 2018 , Pages 1501-1515 ; 09544070 (ISSN) Mohebbi, M ; Reyhanian, M ; Ghofrani, I ; Aziz, A. A ; Hosseini, V ; Sharif University of Technology
    SAGE Publications Ltd  2018
    Unfortunately, energy demands and destruction of the environment from uncontrolled manipulation of fossil fuels have increased. Climate change concerns have resulted in the rapid use of new, alternative combustion technologies. In this study, reactivity controlled compression ignition (RCCI) combustion, which can simply be exploited in internal combustion (IC) engines, is investigated. To introduce and identify extra insightful information, an exergy-based study was conducted to classify various irreversibility and loss sources. Multidimensional models were combined with the primary kinetics mechanism to investigate RCCI combustion, incorporating the second law of thermodynamics. The... 

    Performance and emissions of a reactivity controlled light-duty diesel engine fueled with n-butanol-diesel and gasoline

    , Article Applied Thermal Engineering ; Volume 134 , April , 2018 , Pages 214-228 ; 13594311 (ISSN) Mohebbi, M ; Reyhanian, M ; Hosseini, V ; Muhamad Said, M. F ; Aziz, A. A ; Sharif University of Technology
    Elsevier Ltd  2018
    Reactivity Controlled Compression Ignition can be extended over a wide spectrum of fuels and is anticipated as a promising strategy in meeting current and future emission regulations. In this study, the effect of n-butanol addition on combustion characteristics and emissions in a reactivity controlled engine was investigated experimentally. Different ratios of butanol-diesel blends at different settings of EGR and premixed ratios were applied to a light duty diesel engine. The butanol-diesel blends were directly injected into the combustion chamber while gasoline was injected at the intake port. Combustion phasing was maintained at 2.7 °CA for all of test points by adjusting fuel injection... 

    Beneficial Role of oxygen in co and propylene oxidation over a pt-pd-based wiremesh catalyst as a retrofit emission control device for four-stroke gasoline spark-ignited motorcycles

    , Article Energy and Fuels ; Volume 35, Issue 12 , 2021 , Pages 10122-10133 ; 08870624 (ISSN) Lotfollahzade Moghaddam, A ; Hamzehlouyan, T ; Hosseini, V ; Mayer, A ; Sharif University of Technology
    American Chemical Society  2021
    Over 200 million motorcycles in use worldwide account for a substantial portion of global mobile source total hydrocarbons (THC) and carbon monoxide (CO) emissions. In Tehran, capital of Iran, ultrarich inefficient combustion in gasoline-fueled motorcycles results in significantly high CO and THC emissions. Motorcycle catalysts can reduce CO and C3H6(as a representative hydrocarbon) emission factors by 60-80%. In the present work, CO and propylene oxidation over a commercial Pt-Pd-based wiremesh catalyst is studied in a flow reactor setup under simulated conditions relevant to 125 cc four-stroke gasoline carburetor motorcycles. Steady-state individual and co-oxidation tests for CO and... 

    An assessment of gasoline motorcycle emissions performance and understanding their contribution to Tehran air pollution

    , Article Transportation Research Part D: Transport and Environment ; Volume 47 , 2016 , Pages 1-12 ; 13619209 (ISSN) Hassani, A ; Hosseini, V ; Sharif University of Technology
    Elsevier Ltd 
    Motorcycles are the third most common means of transportation in the megacity of Tehran. Hence, measurements of emission factors are essential for Tehran motorcycle fleets. In this study, 60 carburetor motorcycles of various mileages and engine displacement volumes were tested in a chassis dynamometer laboratory according to cold start Euro-3 emissions certification test procedures. For almost all of the tested samples, the average carbon monoxide (CO) emission factors were about seven times higher than the limits for Euro-3 certification. No motorcycle fell within the Euro-3 certification limit on CO emissions. 125 cc engine displacement volume motorcycles, which are dominant in Tehran,... 

    A comparison of light-duty vehicles' high emitters fractions obtained from an emission remote sensing campaign and emission inspection program for policy recommendation

    , Article Environmental Pollution ; Volume 286 , 2021 ; 02697491 (ISSN) Hassani, A ; Safavi, S. R ; Hosseini, V ; Sharif University of Technology
    Elsevier Ltd  2021
    Urban transportation is one of the leading causes of air pollution in big cities. In-use emissions of vehicles are higher than the emission control certification levels. The current study uses a roadside remote sensing emission monitoring campaign to investigate (a) fraction of high emitters in the light-duty vehicle (LDV) fleet and their contributions to the total emissions, (b) emission inspection (I/M) programs' effectiveness, and (c) alternate fuel (natural gas) encouragement policy. LDVs consist of passenger or freight transport vehicles with four wheels equivalent to classes M1 and N1 of European union vehicle classifications. The motivation is to assess the current emission inspection... 

    An experimental study on the effect of hydrogen enrichment on diesel fueled HCCI combustion

    , Article International Journal of Hydrogen Energy ; Volume 36, Issue 21 , 2011 , Pages 13820-13830 ; 03603199 (ISSN) Guo, H ; Hosseini, V ; Neill, W. S ; Chippior, W. L ; Dumitrescu, C. E ; Sharif University of Technology
    This paper experimentally investigates the influence of hydrogen enrichment on the combustion and emission characteristics of a diesel HCCI engine using a modified Cooperative Fuel Research (CFR) engine. Three fuels, n-heptane and two middle distillates with cetane numbers of 46.6 and 36.6, are studied. The results show that hydrogen enrichment retards the combustion phasing and reduces the combustion duration of a diesel HCCI engine. Besides, hydrogen enrichment increases the power output and fuel conversion efficiency, and improves the combustion stability. However, hydrogen enrichment may narrow the operational compression ratio range and increase the knocking tendency. Both the overall... 

    An experimental study on low temperature combustion in a light duty engine fueled with diesel/CNG and biodiesel/CNG

    , Article Fuel ; Volume 262 , 2020 Ghaffarzadeh, S ; Nassiri Toosi, A ; Hosseini, V ; Sharif University of Technology
    Elsevier Ltd  2020
    Low temperature combustion potentially can improve engine efficiency coupled with the benefits of low nitrogen oxides, and particulate matter emissions, and vice versa high unburned hydrocarbon and carbon oxide emissions through in-cylinder fuel reactions. In this survey, the experiments were carried out using a modified one-cylinder reactivity controlled compression ignition engine, dual-fueled diesel/compressed natural gas and biodiesel/CNG, to investigate the effects of direct injection strategies on the engine combustion efficiency and emission characteristics. Different ratios of biodiesel blends at different premixed ratios were applied to the dual-fuel engine. The results showed that... 

    Modeling the formation of traditional and non-traditional secondary organic aerosols from in-use, on-road gasoline and diesel vehicles exhaust

    , Article Journal of Aerosol Science ; Volume 124 , 2018 , Pages 68-82 ; 00218502 (ISSN) Esmaeilirad, S ; Hosseini, V ; Sharif University of Technology
    Elsevier Ltd  2018
    In this study, we implement a numerical model to predict secondary organic aerosol (SOA) formation from semi- and intermediate-volatility organic compounds emitted from in-use gasoline and diesel vehicles. The model is formulated based on the volatility basis set (VBS) approach, and it accounts for OH oxidation of unspeciated low-volatility organics, which are classified by their volatility. This model incorporates SOA formation data from smog chamber and emission measurements of vehicle exhaust in a Hybrid framework to calculate the contribution of both traditional and non-traditional SOA precursors to total SOA formation observed in photo-oxidation experiments. Emission and SOA formation... 

    Source apportionment of fine particulate matter in a Middle Eastern Metropolis, Tehran-Iran, using PMF with organic and inorganic markers

    , Article Science of the Total Environment ; Volume 705 , 2020 Esmaeilirad, S ; Lai, A ; Abbaszade, G ; Schnelle Kreis, J ; Zimmermann, R ; Uzu, G ; Daellenbach, K ; Canonaco, F ; Hassankhany, H ; Arhami, M ; Baltensperger, U ; Prévôt, A. S. H ; Schauer, J. J ; Jaffrezo, J. L ; Hosseini, V ; El Haddad, I ; Sharif University of Technology
    Elsevier B.V  2020
    With over 8 million inhabitants and 4 million motor vehicles on the streets, Tehran is one of the most crowded and polluted cities in the Middle East. Frequent exceedances of national daily PM2.5 limit have been reported in this city during the last decade, yet, the chemical composition and sources of fine particles are poorly determined. In the present study, 24-hour PM2.5 samples were collected at two urban sites during two separate campaigns, a one-year period from 2014 to 2015 and another three-month period at the beginning of 2017. Concentrations of organic carbon (OC), elemental carbon (EC), inorganic ions, trace metals and specific organic molecular markers were measured by chemical... 

    Secondary organic aerosol formation from untreated exhaust of gasoline four-stroke motorcycles

    , Article Urban Climate ; 2021 , Volume 36 ; 22120955 (ISSN) Esmaeilirad, S ; Setyan, A ; Wang, J ; Hosseini, V ; Sharif University of Technology
    Elsevier B.V  2021
    This study investigates the secondary organic aerosol (SOA) formation potential of carburetor motorcycles exhaust. This type of two-wheeler is a popular means of transport in many Asian cities. A volatility-based numerical model was employed to predict SOA formation from a fleet of motorcycles in Tehran, capital of Iran. The fleet was a combination of four-stroke, gasoline-powered motorcycles with different engine displacement volumes. Total hydrocarbon (THC) emission factors of all motorcycles were previously measured in a chassis dynamometer laboratory according to cold start Euro-3 emissions certification test procedures. Due to incomplete combustion and lack of control on exhaust... 

    3D Bioprinting of oxygenated cell-laden gelatin methacryloyl constructs

    , Article Advanced Healthcare Materials ; Volume 9, Issue 15 , 2020 Erdem, A ; Darabi, M. A ; Nasiri, R ; Sangabathuni, S ; Ertas, Y. N ; Alem, H ; Hosseini, V ; Shamloo, A ; Nasr, A. S ; Ahadian, S ; Dokmeci, M. R ; Khademhosseini, A ; Ashammakhi, N ; Sharif University of Technology
    Wiley-VCH Verlag  2020
    Cell survival during the early stages of transplantation and before new blood vessels formation is a major challenge in translational applications of 3D bioprinted tissues. Supplementing oxygen (O2) to transplanted cells via an O2 generating source such as calcium peroxide (CPO) is an attractive approach to ensure cell viability. Calcium peroxide also produces calcium hydroxide that reduces the viscosity of bioinks, which is a limiting factor for bioprinting. Therefore, adapting this solution into 3D bioprinting is of significant importance. In this study, a gelatin methacryloyl (GelMA) bioink that is optimized in terms of pH and viscosity is developed. The improved rheological properties... 

    Solid nanoparticle and gaseous emissions of a diesel engine with a diesel particulate filter and use of a high-sulphur diesel fuel and a medium-sulphur diesel fuel

    , Article Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering ; Volume 231, Issue 7 , 2017 , Pages 941-951 ; 09544070 (ISSN) Doozandegan, M ; Hosseini, V ; Ehteram, M. A ; Sharif University of Technology
    High-sulphur and medium-sulphur diesel fuels are still used in several countries. Although diesel particulate filter technology for on-road diesel engines has existed since 1989, the availability of high-sulphur and medium-sulphur diesel fuels in the market causes delays in the use of catalysed filter technologies. However, the situation in places such as Tehran is considered unhealthy because of particles and black carbon, and full distribution of ultra-low-sulphur diesel is awaited eagerly. The purpose of this study is to investigate the effect of the sulphur content in fuels on the gaseous and solid exhaust emissions of a 220 kW Euro II engine equipped with a sintered metal active-passive... 

    Development of اot exhaust emission factors for iranian-made euro-2 certified light-duty vehicles

    , Article Environmental Science and Technology ; Volume 50, Issue 1 , 2016 , Pages 279-284 ; 0013936X (ISSN) Banitalebi, E ; Hosseini, V ; Sharif University of Technology
    American Chemical Society  2016
    Emission factors (EFs) are fundamental, necessary data for air pollution research and scenario implementation. With the vision of generating national EFs of the Iranian transportation system, a portable emission measurement system (PEMS) was used to develop the basic EFs for a statistically significant sample of Iranian gasoline-fueled privately owned light duty vehicles (LDVs) operated in Tehran. A smaller sample size of the same fleet was examined by chassis dynamometer (CD) bag emission measurement tests to quantify the systematic differences between the PEMS and CD methods. The selected fleet was tested over four different routes of uphill highways, flat highways, uphill urban streets,... 

    Seasonal trends, chemical speciation and source apportionment of fine PM in Tehran

    , Article Atmospheric Environment ; Volume 153 , 2017 , Pages 70-82 ; 13522310 (ISSN) Arhami, M ; Hosseini, V ; Zare Shahne, M ; Bigdeli, M ; Lai, A ; Schauer, J. J ; Sharif University of Technology
    Elsevier Ltd  2017
    Frequent air pollution episodes have been reported for Tehran, Iran, mainly because of critically high levels of fine particulate matter (PM2.5). The composition and sources of these particles are poorly known, so this study aims to identify the major components and heavy metals in PM2.5along with their seasonal trends and associated sources. 24-hour PM2.5samples were collected at a main residential station every 6 days for a full year from February 2014 to February 2015. The samples were analyzed for ions, organic carbon (including water-soluble and insoluble portions), elemental carbon (EC), and all detectable elements. The dominant mass components, which were determined by means of... 

    Seasonal trends in the composition and sources of PM2.5 and carbonaceous aerosol in Tehran, Iran

    , Article Environmental Pollution ; Volume 239 , 2018 , Pages 69-81 ; 02697491 (ISSN) Arhami, M ; Zare Shahne, M ; Hosseini, V ; Roufigar Haghighat, N ; Lai, A. M ; Schauer, J. J ; Sharif University of Technology
    Elsevier Ltd  2018
    Currently PM2.5 is a major air pollution concern in Tehran, Iran due to frequent high levels and possible adverse impacts. In this study, which is the first of its kind to take place in Tehran, composition and sources of PM2.5 and carbonaceous aerosol were determined, and their seasonal trends were studied. In this regard, fine PM samples were collected every six days at a residential station for one year and the chemical constituents including organic marker species, metals, and ions were analyzed by chemical analysis. The source apportionment was performed using organic molecular marker-based CMB receptor modeling. Carbonaceous compounds were the major contributors to fine particulate mass... 

    Annual and seasonal spatial models for nitrogen oxides in Tehran, Iran

    , Article Scientific Reports ; Volume 6 , 2016 ; 20452322 (ISSN) Amini, H ; Taghavi Shahri, S. M ; Henderson, S. B ; Hosseini, V ; Hassankhany, H ; Naderi, M ; Ahadi, S ; Schindler, C ; Künzli, N ; Yunesian, M ; Sharif University of Technology
    Nature Publishing Group 
    Very few land use regression (LUR) models have been developed for megacities in low- and middle-income countries, but such models are needed to facilitate epidemiologic research on air pollution. We developed annual and seasonal LUR models for ambient oxides of nitrogen (NO, NO2, and NOX) in the Middle Eastern city of Tehran, Iran, using 2010 data from 23 fixed monitoring stations. A novel systematic algorithm was developed for spatial modeling. The R 2 values for the LUR models ranged from 0.69 to 0.78 for NO, 0.64 to 0.75 for NO 2, and 0.61 to 0.79 for NOx. The most predictive variables were: distance to the traffic access control zone; distance to primary schools; green space; official... 

    Land use regression models for Alkylbenzenes in a middle eastern megacity: Tehran study of exposure prediction for environmental health research (tehran sepehr)

    , Article Environmental Science and Technology ; Volume 51, Issue 15 , 2017 , Pages 8481-8490 ; 0013936X (ISSN) Amini, H ; Schindler, C ; Hosseini, V ; Yunesian, M ; Künzli, N ; Sharif University of Technology
    American Chemical Society  2017
    Land use regression (LUR) has not been applied thus far to ambient alkylbenzenes in highly polluted megacities. We advanced LUR models for benzene, toluene, ethylbenzene, p-xylene, m-xylene, o-xylene (BTEX), and total BTEX using measurement based estimates of annual means at 179 sites in Tehran megacity, Iran. Overall, 520 predictors were evaluated, such as The Weather Research and Forecasting Model meteorology predictions, emission inventory, and several new others. The final models with R2 values ranging from 0.64 for p-xylene to 0.70 for benzene were mainly driven by traffic-related variables but the proximity to sewage treatment plants was present in all models indicating a major local... 

    Spatiotemporal description of BTEX volatile organic compounds in a middle eastern megacity: tehran study of exposure prediction for environmental health research (Tehran SEPEHR)

    , Article Environmental Pollution ; Volume 226 , 2017 , Pages 219-229 ; 02697491 (ISSN) Amini, H ; Hosseini, V ; Schindler, C ; Hassankhany, H ; Yunesian, M ; Henderson, S. B ; Künzli, N ; Sharif University of Technology
    The spatiotemporal variability of ambient volatile organic compounds (VOCs) in Tehran, Iran, is not well understood. Here we present the design, methods, and results of the Tehran Study of Exposure Prediction for Environmental Health Research (Tehran SEPEHR) on ambient concentrations of benzene, toluene, ethylbenzene, p-xylene, m-xylene, o-xylene (BTEX), and total BTEX. To date, this is the largest study of its kind in a low- and middle-income country and one of the largest globally. We measured BTEX concentrations at five reference sites and 174 distributed sites identified by a cluster analytic method. Samples were taken over 25 consecutive 2-weeks at five reference sites (to be used for...