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    Various effects of reformer gas enrichment on natural-gas, iso-octane and normal-heptane HCCI combustion using artificial inert species method

    , Article Energy Conversion and Management ; Volume 159 , March , 2018 , Pages 7-19 ; 01968904 (ISSN) Reyhanian, M ; Hosseini, V ; Sharif University of Technology
    Elsevier Ltd  2018
    Abstract
    Reformer gas (syngas) addition to main fuel is a practical solution for combustion timing control in HCCI engines. This study emphasizes the understanding of various effects of reformer gas (RG) addition, with composition of 75%vol H2 and 25%vol CO, in HCCI combustion by developing an artificial inert species method and using a detailed chemical kinetics multi-zone model. Three fuels (iso-octane, n-heptane, and natural gas) with different autoignition characteristics were used in this study. The developed multi-zone model was validated for mentioned fuels at various percentages of RG using six experimental cases of a single-cylinder CFR engine. The results showed that increasing reformer gas... 

    Time-variant reliability-based prediction of COVID-19 spread using extended SEIVR model and Monte Carlo sampling

    , Article Results in Physics ; Volume 26 , 2021 ; 22113797 (ISSN) Shadabfar, M ; Mahsuli, M ; Sioofy Khoojine, A ; Hosseini, V. R ; Sharif University of Technology
    Elsevier B.V  2021
    Abstract
    A probabilistic method is proposed in this study to predict the spreading profile of the coronavirus disease 2019 (COVID-19) in the United State (US) via time-variant reliability analysis. To this end, an extended susceptible-exposed-infected-vaccinated-recovered (SEIVR) epidemic model is first established deterministically, considering the quarantine and vaccination effects, and then applied to the available COVID-19 data from US. Afterwards, the prediction results are described as a time-series of the number of people infected, recovered, and dead. Upon introducing the extended SEIVR model into a limit-state function and defining the model parameters including transmission, recovery, and... 

    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
    Abstract
    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... 

    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
    Abstract
    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... 

    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
    Abstract
    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... 

    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
    Abstract
    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... 

    Short-term associations between daily mortality and ambient particulate matter, nitrogen dioxide, and the air quality index in a Middle Eastern megacity

    , Article Environmental Pollution ; Volume 254 , 2019 ; 02697491 (ISSN) Amini, H ; Trang Nhung, N. T ; Schindler, C ; Yunesian, M ; Hosseini, V ; Shamsipour, M ; Hassanvand, M. S ; Mohammadi, Y ; Farzadfar, F ; Vicedo Cabrera, A. M ; Schwartz, J ; Henderson, S. B ; Künzli, N ; Sharif University of Technology
    Elsevier Ltd  2019
    Abstract
    There is limited evidence for short-term association between mortality and ambient air pollution in the Middle East and no study has evaluated exposure windows of about a month prior to death. We investigated all-cause non-accidental daily mortality and its association with fine particulate matter (PM2.5), nitrogen dioxide (NO2), and the Air Quality Index (AQI) from March 2011 through March 2014 in the megacity of Tehran, Iran. Generalized additive quasi-Poisson models were used within a distributed lag linear modeling framework to estimate the cumulative effects of PM2.5, NO2, and the AQI up to a lag of 45 days. We further conducted multi-pollutant models and also stratified the analyses by... 

    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
    Abstract
    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... 

    Seasonal variations in the oxidative stress and inflammatory potential of PM2.5 in Tehran using an alveolar macrophage model; The role of chemical composition and sources

    , Article Environment International ; Volume 123 , 2019 , Pages 417-427 ; 01604120 (ISSN) Al Hanai, A. H ; Antkiewicz, D. S ; Hemming, J. D. C ; Shafer, M. M ; Lai, A. M ; Arhami, M ; Hosseini, V ; Schauer, J. J ; Sharif University of Technology
    Elsevier Ltd  2019
    Abstract
    The current study was designed to assess the association between temporal variations in urban PM2.5 chemical composition, sources, and the oxidative stress and inflammatory response in an alveolar macrophage (AM) model. A year-long sampling campaign collected PM2.5 samples at the Sharif University in Tehran, Iran. PM-induced reactive oxygen species (ROS) production was measured both with an acellular dithiothreitol consumption assay (DTT-ROS; ranged from 2.1 to 9.3 nmoles min−1 m−3) and an in vitro macrophage-mediated ROS production assay (AM-ROS; ranged from 125 to 1213 μg Zymosan equivalents m−3). The production of tumor necrosis factor alpha (TNF-α; ranged from ~60 to 518 pg TNF-α m−3)... 

    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
    Abstract
    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... 

    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
    Abstract
    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... 

    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
    Abstract
    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... 

    Particulate emissions of real-world light-duty gasoline vehicle fleet in Iran

    , Article Environmental Pollution ; Volume 292 , 2022 ; 02697491 (ISSN) Shahne, M. Z ; Arhami, M ; Hosseini, V ; Al Haddad, E ; Sharif University of Technology
    Elsevier Ltd  2022
    Abstract
    Fine particulate matter cause profound adverse health effects in Iran. Road traffic is one of the main sources of particulate matter (PM) in urban areas, and has a large contribution in PM2.5 and organic carbon concentration, in Tehran, Iran. The composition of fine PM vehicle emission is poorly known, so this paper aims to determine the mixed fleet source profile by using the analysed data from the two internal stations and the emission factor for PM light-duty vehicles emission. Tunnels are ideal media for extraction vehicle source profile and emission factor, due to vehicles are the only source of pollutant in the urban tunnels. In this study, PM samples were collected simultaneously in... 

    Network autoregressive model for the prediction of covid-19 considering the disease interaction in neighboring countries

    , Article Entropy ; Volume 23, Issue 10 , 2021 ; 10994300 (ISSN) Sioofy Khoojine, A ; Shadabfar, M ; Hosseini, V. R ; Kordestani, H ; Sharif University of Technology
    MDPI  2021
    Abstract
    Predicting the way diseases spread in different societies has been thus far documented as one of the most important tools for control strategies and policy-making during a pandemic. This study is to propose a network autoregressive (NAR) model to forecast the number of total currently infected cases with coronavirus disease 2019 (COVID-19) in Iran until the end of December 2021 in view of the disease interactions within the neighboring countries in the region. For this purpose, the COVID-19 data were initially collected for seven regional nations, including Iran, Turkey, Iraq, Azerbaijan, Armenia, Afghanistan, and Pakistan. Thenceforth, a network was established over these countries, and the... 

    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
    Abstract
    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... 

    Modeling particle deposition in the respiratory system during successive respiratory cycles

    , Article Scientia Iranica ; Volume 27, Issue 1 B , February , 2020 , Pages 215-228 Nemati, H ; Saidi, M. S ; Hosseini, V ; Sharif University of Technology
    Sharif University of Technology  2020
    Abstract
    This study uses a 5-lobe symmetric model to investigate total, lobar and generational particle deposition fractions in the lungs during successive cycles. It was found that for the particle size between 0.05 and 2 μm and the tidal volumes greater than 1000 ml, the effect of successive cycles helped predict more deposition fraction per cycle up to about 16% than that of a single cycle. The mentioned range of tidal volumes corresponds to light or heavy physical activities. Therefore, it can be understood that people, when physically active, exposed to particulate matter within the mentioned size range are at higher health risk as compared to both the resting state and the same state... 

    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
    Abstract
    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... 

    Micro and nanoscale technologies in oral drug delivery

    , Article Advanced Drug Delivery Reviews ; Volume 157 , 2020 , Pages 37-62 Ahadian, S ; Finbloom, J. A ; Mofidfar, M ; Diltemiz, S. E ; Nasrollahi, F ; Davoodi, E ; Hosseini, V ; Mylonaki, I ; Sangabathuni, S ; Montazerian, H ; Fetah, K ; Nasiri, R ; Dokmeci, M. R ; Stevens, M. M ; Desai, T. A ; Khademhosseini, A ; Sharif University of Technology
    Elsevier B.V  2020
    Abstract
    Oral administration is a pillar of the pharmaceutical industry and yet it remains challenging to administer hydrophilic therapeutics by the oral route. Smart and controlled oral drug delivery could bypass the physiological barriers that limit the oral delivery of these therapeutics. Micro- and nanoscale technologies, with an unprecedented ability to create, control, and measure micro- or nanoenvironments, have found tremendous applications in biology and medicine. In particular, significant advances have been made in using these technologies for oral drug delivery. In this review, we briefly describe biological barriers to oral drug delivery and micro and nanoscale fabrication technologies.... 

    Large eddy simulation of GDI single-hole and multi-hole injector sprays with comparison of numerical break-up models and coefficients

    , Article Journal of Applied Fluid Mechanics ; Volume 9, Issue 2 , 2016 , Pages 1013-1022 ; 17353572 (ISSN) Zamani, H ; Hosseini, V ; Afshin, H ; Allocca, L ; Baloo, M ; Sharif University of Technology
    Isfahan University of Technology  2016
    Abstract
    In the present study the fuel spray of a gasoline direct injected engine with multi-hole injector is simulated. Simulation inputs data, injection flow rate and spray cone angle are obtained from previous experimental studies. Log-normal distribution with different standard deviation is used for initial droplet size as the primary break-up model in order to reach the agreement between experimental and calculated spray tip penetration. As the first step, only one plume of spray injected into a quiescent air environment is simulated and validated by varying break-up model and standard deviation. Then, with coefficient obtained from the single jet simulation all six spray jets are simulated... 

    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
    Abstract
    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...