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- Andersson, C., et al.
(författare)
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Fully electric ship propulsion reduces airborne noise but not underwater noise
- 2024
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Ingår i: Ocean Engineering. - Göteborg : Elsevier. - 0029-8018 .- 1873-5258. ; 302
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Tidskriftsartikel (refereegranskat)abstract
- Electrification of ships offers zero-emission travel and is spreading rapidly, but the relation between electric ship propulsion and noise pollution is not generally understood. Here, three different types of diesel-electric hybrid ferries have been measured in two operating modes: running in hybrid mode with the diesel engine powering an electric generator; and running in fully electric battery powered mode. Measurements were performed to simultaneously quantify airborne and underwater radiated noise. Findings are that on-board diesel engines for electricity generation do not contribute a large extent of the underwater radiated noise, whilst a major source of airborne low-frequency radiation.
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| 2. |
- Cha, Yingying, 1989-, et al.
(författare)
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On particulate emissions from individual trains in tunnel environments
- 2016
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Ingår i: Civil-Comp Proceedings. - : Civil-Comp Press. - 1759-3433. ; 110
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Tidskriftsartikel (refereegranskat)abstract
- In order to detect the concentrations and size distributions of airborne particles that were generated by individual moving trains on an underground railway platform, a series of real-time measurements were undertaken. The measurement range covered the ultrafine (less than 100 nm) and partly the fine (100 nm to 2.5 μm), but not the coarse fraction (2.5 to 10 μm). The results show that the individual trains with stop and start at the platform elevate substantially the particulate number concentrations with a diameter size greater than 100 nm. Two size modes of the particulate number concentrations are obtained. One mode peaks around 170 nm when a train stopped/started, while the other is around 30 nm when no train operated in the station. By using principal component analysis, four components are extracted from the thirty two-analyzed particulate sizes, indicating four different contributors in those detected particles. It is revealed from this study that the particulate matter released by individual moving trains (mainly through mechanical wear and turbulent resuspension) is a key contributing source of the fine particles on underground railway platforms, which can be separated from the background by their different size distributions.
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| 3. |
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| 4. |
- Selander, Helena, 1975-, et al.
(författare)
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Older drivers: On-road and off-road test results
- 2011
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Ingår i: Accident Analysis and Prevention. - : Elsevier Science B.V., Amsterdam.. - 0001-4575 .- 1879-2057. ; 43:4, s. 1348-1354
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Tidskriftsartikel (refereegranskat)abstract
- Eighty-five volunteer drivers, 65-85 years old, without cognitive impairments impacting on their driving were examined, in order to investigate driving errors characteristic for older drivers. In addition, any relationships between cognitive off-road and on-road tests results, the latter being the gold standard, were identified. Performance measurements included Trail Making Test (TMT), Nordic Stroke Driver Screening Assessment (NorSDSA), Useful Field of View (UFOV), self-rating driving performance and the two on-road protocols P-Drive and ROA. Some of the older drivers displayed questionable driving behaviour. In total, 21% of the participants failed the on-road assessment. Some of the specific errors were more serious than others. The most common driving errors embraced speed: exceeding the speed limit or not controlling the speed. Correlations with the P-Drive protocol were established for NorSDSA total score (weak), UFOV subtest 2 (weak), and UFOV subtest 3 (moderate). Correlations with the ROA protocol were established for UFOV subtest 2 (weak) and UFOV subtest 3 (weak). P-Drive and self ratings correlated weakly, whereas no correlation between self ratings and the ROA protocol was found. The results suggest that specific problems or errors seen in an older persons driving can actually be "normal driving behaviours".
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