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Zhang S, Zhou X, Chen Q, Yang X, Zhou H, Luo L, Luo Y. Carsim-based simulation study on the performances of raised speed deceleration facilities under different profiles. TRAFFIC INJURY PREVENTION 2024; 25:810-818. [PMID: 38717830 DOI: 10.1080/15389588.2024.2346229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 04/18/2024] [Indexed: 07/07/2024]
Abstract
OBJECTIVE Studying the optimal profile shape and size of deceleration facilities suitable for low-speed environment roads under different speed control intervals. METHODS Simulation modeling of deceleration facilities with various profile shapes and sizes and for vehicles in different speed intervals was performed using the vehicle dynamics simulation software Carsim. The height jumped by a vehicle's wheels, the vertical force on the wheels, and the vertical acceleration of the vehicle were used as indicators of ride comfort and operational stability for the various deceleration facility profiles. RESULTS stability and comfort were related to the contour of the deceleration facility. Vertical forces were positively related to vehicle jump height, but the jump heights of vehicles passing through deceleration mounds with different planes at the same speed were not significantly different with increasing height. When the vehicle is traveling slowly, the vertical impact force on the vehicle is not significantly related to the speed loss of the vehicle. CONCLUSIONS Within the speed range of 20-60 km/h and profile heights of 3-10.5 cm, the effectiveness ratings of circular high width and parabolic were basically at level 2 and level 3, but the circular high width had a more stable jump height and was the best profile form, followed by sinusoidal and parabolic, then isosceles trapezoidal, and lastly conventional speed bumps.
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Affiliation(s)
- Shibo Zhang
- School of Automobile and Transportation, Xihua University, Chengdu, China
- Provincial Engineering Research Center for New Energy Vehicle Intelligent Control and Simulation Test Technology of Sichuan, Chengdu, China
| | - Xixi Zhou
- School of Automobile and Transportation, Xihua University, Chengdu, China
| | - Quanlin Chen
- School of Automobile and Transportation, Xihua University, Chengdu, China
| | - Xuefeng Yang
- School of Automobile and Transportation, Xihua University, Chengdu, China
| | - Hua Zhou
- School of Automobile and Transportation, Xihua University, Chengdu, China
| | - Longhao Luo
- Sichuan Vocational and Technical College of Communications, Chengdu, China
| | - Yong Luo
- Sichuan Vocational and Technical College of Communications, Chengdu, China
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Colyer PM, Hoque MA, Fowler M. A chemical and ecological assessment into elemental loading from ford crossings in Ashdown Forest, Sussex, United Kingdom. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 738:140102. [PMID: 32806365 DOI: 10.1016/j.scitotenv.2020.140102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 06/07/2020] [Accepted: 06/08/2020] [Indexed: 06/11/2023]
Abstract
Numerous studies have identified the issue of road surface runoff as a source of contamination into waterways but the impact of vehicular wash-off is less well understood. A ford crossing provides a pathway for vehicle-derived contaminants emanating from both road surface runoff and vehicular wash-off into a river system. Twyford Lane Ford (Ford 1) and Birchgrove Lane Ford (Ford 2), located ca. 600 m apart on a tributary of the River Ouse in Sussex (UK), were the focus of this study. A combination of biomonitoring (assessment of benthic macroinvertebrates) and chemical assessments of water and sediments has been undertaken to determine any detrimental impacts, such as a lack in biodiversity, resulting from the ford crossings. Sediment concentrations of chromium (Cr3+), lead (Pb) and zinc (Zn) were generally elevated at Ford 1, attenuating at sampling points between the fords to then peak at Ford 2. However, sediment particle size was seen to have an influence on elemental concentrations. In general, an increase in elemental concentrations was associated with a higher percentage of fine-grained sediments (≤63 μm). Elevated concentrations of Zn and magnesium (Mg) were identified within water samples taken during a precipitation event following a prolonged dry period. The biomonitoring results found reduced BMWP (Biological Monitoring Working Party) scores at positions close to the ford crossings, and where the stream was in proximity to the roadside. Sensitive Ephemeroptera were largely absent at sampling points closest to the fords, which is likely to be associated with elevated Zn. The results suggest that careful consideration should be applied when selecting crossing points over sensitive waters.
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Affiliation(s)
- P M Colyer
- School of the Environment, Geography and Geosciences, University of Portsmouth, Portsmouth PO1 3QL, UK.
| | - M A Hoque
- School of the Environment, Geography and Geosciences, University of Portsmouth, Portsmouth PO1 3QL, UK
| | - M Fowler
- School of the Environment, Geography and Geosciences, University of Portsmouth, Portsmouth PO1 3QL, UK
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Men C, Liu R, Xu L, Wang Q, Guo L, Miao Y, Shen Z. Source-specific ecological risk analysis and critical source identification of heavy metals in road dust in Beijing, China. JOURNAL OF HAZARDOUS MATERIALS 2020; 388:121763. [PMID: 31818668 DOI: 10.1016/j.jhazmat.2019.121763] [Citation(s) in RCA: 134] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2019] [Revised: 11/24/2019] [Accepted: 11/25/2019] [Indexed: 05/11/2023]
Abstract
To explore the spatial variation of source-specific ecological risks and identify critical sources of heavy metals in road dust, 36 road dust samples collected in Beijing in March 2017 were analyzed for heavy metals. A new method that takes into consideration the heavy-metal toxic response and is flexible to changes in the number of calculated heavy metals, called the Nemerow integrated risk index (NIRI), was developed for ecological risk assessment. The NIRI indicated that heavy metals posed considerable to high risks at the majority of sites, and 22 % of the sites suffered extreme risk in spring (NIRI > 320). Four main sources were identified based on positive matrix factorization (PMF): traffic exhaust, fuel combustion, construction, and use of pesticides and fertilizers. Owing to the lower toxic response factors of representative heavy metals of fuel combustion than those of other sources, although fuel combustion had the highest contribution (34.21 %) to heavy metals in spring, it only contributed 5.57 % to ecological risks. Critical sources and critical source areas were determined by considering the contributions to both heavy metals and ecological risks. The use of pesticide and fertilizer and traffic-related exhaust were identified as critical sources of heavy metals in spring. Source-specific ecological risks and critical sources of heavy metals changed with the changing seasons, which suggests that different strategies should be adopted in different seasons.
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Affiliation(s)
- Cong Men
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Beijing, 100875, China
| | - Ruimin Liu
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Beijing, 100875, China.
| | - Libing Xu
- College of Agronomy, Nanjing Agricultural University, Nanjing, 210095, China
| | - Qingrui Wang
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Beijing, 100875, China
| | - Lijia Guo
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Beijing, 100875, China
| | - Yuexi Miao
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Beijing, 100875, China
| | - Zhenyao Shen
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, No. 19, Xinjiekouwai Street, Beijing, 100875, China
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Liang SY, Cui JL, Bi XY, Luo XS, Li XD. Deciphering source contributions of trace metal contamination in urban soil, road dust, and foliar dust of Guangzhou, southern China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2019; 695:133596. [PMID: 31421330 DOI: 10.1016/j.scitotenv.2019.133596] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2018] [Revised: 07/20/2019] [Accepted: 07/24/2019] [Indexed: 05/25/2023]
Abstract
Trace metal contamination prevails in various compartments of the urban environment. Understanding the roles of various anthropogenic sources in urban trace metal contamination is critical for pollution control and city development. In this study, the source contribution from various contamination sources to trace metal contamination (e.g., Cu, Pb, Zn, Co, Cr and Ni) in different environmental compartments in a typical megacity, Guangzhou, southern China, was investigated using the receptor model (Absolute Principal Component Scores-Multiple Linear Regression, APCS-MLR) coupled with the Kriging technique. Lead isotopic data and APCS-MLR analysis identified industrial and traffic emissions as the major sources of trace metals in surface soil, road dust, and foliar dust in Guangzhou. Lead isotopic compositions of road dust and foliar dust exhibited similar ranges, implying their similar sources and potential metal exchange between them. Re-suspended soil contributed to 0-38% and 25-58% of the trace metals in the road dust and foliar dust, respectively, indicating the transport of the different terrestrial dust. Spatial distribution patterns implied that Cu in the road dust was a good indicator of traffic contamination, particularly with traffic volume and vehicle speed. Lead and Zn in foliar dust indicated mainly industrial contamination, which decreased from the emission source (e.g., a power plant and steel factory) to the surrounding environment. The spatial influence of industry and traffic on the contamination status of road dust/foliar dust was successfully separated from that of other anthropogenic sources. This study demonstrated that anthropogenic inputs of trace metals in various environmental compartments (e.g., urban soil, road dust, and foliar dust) can be evaluated using a combined APCS-MLR receptor model and geostatistical analysis at a megacity scale. The coupled use of APCS-MLR analysis, geostatistics, and Pb isotopes successfully deciphered the spatial influence of the contamination sources in the urban environment matrix, providing some important information for further land remediation and health risk assessment.
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Affiliation(s)
- Si-Yuan Liang
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong
| | - Jin-Li Cui
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong; Key Laboratory for Water Quality and Conservation of the Pearl River Delta, Ministry of Education, School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China
| | - Xiang-Yang Bi
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong; State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China
| | - Xiao-San Luo
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong; International Center for Ecology, Meteorology, and Environment (IceMe), School of Applied Meteorology, Nanjing University of Information Science & Technology, Nanjing 210044, China
| | - Xiang-Dong Li
- Department of Civil and Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong.
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Kumar A, Elumalai SP. Influence of Road Paving on Particulate Matter Emission and Fingerprinting of Elements of Road Dust. ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2018; 75:424-435. [PMID: 30022226 DOI: 10.1007/s00244-018-0546-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 07/04/2018] [Indexed: 06/08/2023]
Abstract
Most assessments of road dust have focused largely on the resuspension of materials from the paved road while the contribution from unpaved shoulder to particulate matter is poorly understood. We evaluated the role of unpaved road shoulders in the contribution of particulate matter emitted by analyzing elements in the road dust. We collected road dust samples and employed US-EPA empirical equations. The results of TSP emission reveal that unpaved shoulder adjacent to paved roads (43.1-29.9%) is a potential emitter than that at roundabouts (27%). In paved road environment, the contribution of TSP emission was 54.9-25.6% from unpaved shoulders based on driving share of vehicles. TSP emission results suggest that waste material is frequently exchanged from paved to unpaved shoulder, which leads to seasonal variations in paved road. The observed particle size of paved surface waste material shows that about 36% particles were less than 2.5 μm and 52% were greater than 10 μm, suggesting that dust is resuspendable and presents a health risk due to being respirable. Elemental analysis confirmed the presence of the toxic elements Cr, Ni, Cu, Zn, Pb, Sn, Sb, and Ba in waste material. Moreover, receptor models indicate that the waste material comprised of elements from tire wear (31%), mineral dust (27%), brake wear (17%), vehicle exhaust (14%), and coal (7%). The elemental contribution of coal is a location-specific source identified from principal component analysis and hierarchical cluster analysis, which originated spillage during transportation. The study illustrates the contributions of PM emission from the different road networks and the mechanism of exchange of waste materials. Microscopic observation of resuspension and transportation of road dust due to vehicular movement leads to advection mechanism at the roundabout and the paved road having unpaved shoulders.
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Affiliation(s)
- Anil Kumar
- Department of Environmental Science and Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad, 826004, India
| | - Suresh Pandian Elumalai
- Department of Environmental Science and Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad, 826004, India.
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