In order to keep high fuel economy of diesel passenger cars, Diesel particulate filter (DPF) is periodically regenerated. In the regeneration process, extra fuel is injected into combustion chambers to achieve high exhaust temperature for the purpose of oxidizing particles accumulating on DPF substrate. It generates significant impacts on passenger car performance and exhaust emissions. In this paper, real-driving performance and exhaust emissions of a diesel car were tested over sixteen drivers under real-world conditions. DPF regeneration events were identified via exhaust temperature. Vehicle power output, fuel economy, and exhaust emissions in the trips both with and without DPF regeneration were analyzed. The results indicated that DPF regeneration events occurred in three of thirty-two test trips, and the maximum exhaust temperature was 250 °C during DPF regeneration. The DPF regeneration event led to the decrease of fuel economy and the increase of particle number, nitrogen oxides and carbon dioxides emission. Particle number emission factors were increased from approximately 10 #/km to 5 × 10 #/km during DPF regeneration. The average power output of the car was in the range of 14.5 kW-15.6 kW and 15.8 kW-18.4 kW for the trips with and without DPF regeneration, respectively. However, Carbon monoxide emission factors were insensitive to DPF regeneration in the test trips.
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http://dx.doi.org/10.1016/j.chemosphere.2022.136629 | DOI Listing |
Environ Sci Technol
January 2025
Center for Environmental Research and Technology (CE-CERT), Bourns College of Engineering, University of California, 1084 Columbia Avenue, Riverside, California 92507, United States.
We assessed the real-world particulate emissions of a goods movement diesel vehicle, with an emphasis on total particle number and solid particle number emissions at different cutoff sizes. The vehicle was tested on routes in the South Coast Air Basin (SCAB) of California, representative of typical goods movement operation between the ports to warehouses and logistic centers with a mixture of urban and highway driving, as well as elevation change. We evaluated emissions during normal vehicle operation and diesel particulate filter (DPF) active regeneration events.
View Article and Find Full Text PDFJ Adv Res
December 2024
State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration & National Clinical Research Center for Oral Diseases & Shaanxi Key Laboratory of Stomatology, Department of Operative Dentistry & Endodontics, School of Stomatology, Fourth Military Medical University, No.145 Western Changle Road, Xi'an, Shaanxi 710032, China. Electronic address:
Introduction: Aging influences the regenerative and reparative functions of dental pulp, and an in-depth and complete understanding of aged dental pulp is highly important.
Objective: This study aimed to explore the heterogeneity of young and aged dental pulp tissue via single-cell RNA sequencing (scRNA-seq), search novel markers of aged dental pulp, and further explore their mechanism.
Methods: ScRNA-seq was employed to analyze the heterogeneity of young and aged dental pulp tissue, and immunohistochemical staining was used to detect new marker Insulin-like Growth Factor Binding Protein 7 (IGFBP7) in aged dental pulp.
J Hazard Mater
December 2024
State Key Laboratory of Automotive Simulation and Control, Jilin University, Changchun 130025, China; College of Automotive Engineering, Jilin University, Changchun 130025, China.
The aim of this paper is to control the DOC outlet gas temperature between 600 ± 15 °C by optimizing the hydrocarbon (HC) injection into the Diesel Oxidation Catalyst (DOC) for active regeneration of the downstream Diesel Particulate Filter (DPF). First, based on the physical model of the DOC thermal dynamics, the energy conservation equation for the gas phase temperature is simplified by using variable substitution, and the energy conservation equation for the solid phase temperature is simplified by considering only the heat generated by the HC injection. By solving the simplified model using the Trapezoidal Rule-Backward Differentiation Formula 2 (TR-BDF2) method and optimizing the model parameters in combination with the Gauss-Newton method, the computational efficiency and accuracy were significantly improved.
View Article and Find Full Text PDFEnviron Res
December 2024
Sustainable Energy and Environmental Thrust, the Hong Kong University of Science and Technology (Guangzhou), Guangzhou, 511458, China. Electronic address:
Diesel vehicle exhaust is one of the major contributors to ultrafine particles (UFPs) in urban areas in China. However, there is still a lack of knowledge about UFPs emission characteristics from current in-use diesel vehicles. This study has carried out an on-road test of 10 in-use Light-duty Diesel Trucks (LDDTs) with different emission control standards in China using a self-established portable measurement system based on the Electronic Low-pressure Impactor (ELPI) and characterized the ultrafine particle number (PN) concentration, particle size distribution and metal element contents.
View Article and Find Full Text PDFBiol Open
September 2024
Bioscience Cardiovascular, Research and Early Development, Cardiovascular, Renal and Metabolism (CVRM), BioPharmaceuticals R&D, AstraZeneca, Gothenburg 431 50, Sweden.
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