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Seyed Reza Safavi

Bio: Seyed Reza Safavi is an academic researcher from Sharif University of Technology. The author has contributed to research in topics: Natural gas vehicle & European union. The author has an hindex of 1, co-authored 1 publications receiving 1 citations.

Papers
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TL;DR: In this paper, the authors used 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, emission inspection (I/M) programs' effectiveness, and alternate fuel (natural gas) encouragement policy.

9 citations


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TL;DR: In this article , the authors measured the emissions before and after representative approaches of tampering of two Euro 6 Diesel light-duty passenger cars, two Euro VI Diesel heavy-duty trucks, and a Stage IV Diesel non-road mobile machinery (NRMM) agricultural tractor.
Abstract: Illegal manipulation (i.e., tampering) of vehicles is a severe problem because vehicle emissions increase orders of magnitude and significantly impact the environment and human health. This study measured the emissions before and after representative approaches of tampering of two Euro 6 Diesel light-duty passenger cars, two Euro VI Diesel heavy-duty trucks, and a Stage IV Diesel non-road mobile machinery (NRMM) agricultural tractor. With tampering of the selective catalytic reduction (SCR) for NOx, the NOx emissions increased by more than one order of magnitude exceeding 1000 mg/km (or mg/kWh) for all vehicles, reaching older Euro or even pre-Euro levels. The tampering of the NOx sensor resulted in relatively low NOx increases, but significant ammonia (NH3) slip. The particle number emissions increased three to four orders of magnitude, reaching 6–10 × 1012 #/km for the passenger car (one order of magnitude higher than the current regulation limit). The tampered passenger car’s NOx and particle number emissions were one order of magnitude higher even compared to the emissions during a regeneration event. This study confirmed that (i) tampering with the help of an expert technician is still possible, even for vehicles complying with the current Euro standards, although this is not allowed by the regulation; (ii) tampering results in extreme increases in emissions.

7 citations

Journal ArticleDOI
TL;DR: In this paper , the use of hybrid unsupervised exploratory plots is broadened with new Exploratory Projection Pursuit techniques, together with clustering techniques, form an intelligent visualisation tool that allows knowledge to be obtained from a previously unknown dataset.
Abstract: Road transport is an integral part of economic activity and is therefore essential for its development. On the downside, it accounts for 30% of the world’s GHG emissions, almost a third of which correspond to the transport of freight in heavy goods vehicles by road. Additionally, means of transport are still evolving technically and are subject to ever more demanding regulations, which aim to reduce their emissions. In order to analyse the sustainability of this activity, this study proposes the application of novel Artificial Intelligence techniques (more specifically, Machine Learning). In this research, the use of Hybrid Unsupervised Exploratory Plots is broadened with new Exploratory Projection Pursuit techniques. These, together with clustering techniques, form an intelligent visualisation tool that allows knowledge to be obtained from a previously unknown dataset. The proposal is tested with a large dataset from the official survey for road transport in Spain, which was conducted over a period of 7 years. The results obtained are interesting and provide encouraging evidence for the use of this tool as a means of intelligent analysis on the subject of developments in the sustainability of road transportation.

3 citations

Journal ArticleDOI
TL;DR: Wang et al. as discussed by the authors quantitatively assessed the emission changes of primary air pollutants (including NOx, CO, VOCs, PM2.5, PM10, and PMTSP) and greenhouse gases (CO2, CH4, and N2O) in the transportation sector with regard to different VECPs in Hainan.

3 citations

Journal ArticleDOI
TL;DR: In this article , a new approach, using enrichment factor in cumulative Pareto analysis is proposed for detecting high emitter vehicle subsets within the vehicle fleet, and their contributions to the total fleet emission are assessed.

3 citations

Journal ArticleDOI
TL;DR: In this paper , the authors developed the realworld heavy-duty vehicle (HDV) emission factors (EFs) for regulated and unregulated pollutants from highway tunnel measurements, a first in India.

2 citations