Wind barrier structures on railway bridges are installed to mitigate the wind effects on travelling trains; however, they cause additional wind loads and associated aerodynamic effects on the bridge. An innovative concept was developed for a wind barrier structure in this study that used a glass-fibre-reinforced polymer (GFRP) that may deform properly when subjected to a crosswind. Such deformation then allows for wind to pass, therefore reducing the wind loads transferred to the bridge. Wind tunnel experiments were conducted on a 1/40-scale train and bridge models with the proposed GFRP barrier subjected to airflow at different speeds up to 20 m/s. The side-force and overturning-moment coefficients of both the train and the bridge were evaluated to characterise the aerodynamic effects. The results show that favourable side-force and overturning-moment coefficients of the train were provided by wind barriers taller than 10 cm. The aerodynamic coefficients of the train were not significantly affected by the airflow speeds; meanwhile, the overturning-moment coefficient of the bridge decreased with the increase in airflow speed due to smaller wind resistance of the barrier after deformation. A numerical analysis was conducted on both the reduced- and full-scale models of the train-barrier-bridge system and the results supported the findings obtained from the wind tunnel experiments.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7560471 | PMC |
http://dx.doi.org/10.3390/ma13184214 | DOI Listing |
Proc Biol Sci
January 2025
Swiss Ornithological Institute, Sempach, Switzerland.
The main features of long-distance migration are derived from landbirds breeding in the Northern Hemisphere. Little is known about migration within the tropics, presumably because tropical species typically move opportunistically and over shorter distances. However, such generalizations are weakened by a lack of solid data on spatial, temporal and behavioural patterns of intra-tropical migrations.
View Article and Find Full Text PDFHeliyon
January 2025
Centre for Nature Positive Solutions, School of Science, STEM College, RMIT University, Melbourne, Australia.
Seaweed aquaculture is growing 8.9 % annually to a forecast US$ 22.13 billion in 2024 and has several environmental, economic and social co-benefits.
View Article and Find Full Text PDFHealth Sci Rep
January 2025
Division of Descriptive Research Indian Council of Medical Research-Headquarters New Delhi Delhi India.
Background And Aims: In the past decade, unmanned aerial systems (UASs), commonly known as drones, have found applications not only in military and agriculture but also in the transportation of medical supplies.
Purpose: The present study was conducted to assess the practicality of utilizing drones as a mode for the delivery of vaccines to combat the challenges.
Study Design: An exploratory study.
Sci Rep
January 2025
Key Laboratory of Ecological Safety and Sustainable Development in Arid Lands/Dunhuang Gobi Desert Ecology and Environment Research Station, Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou, 730000, China.
The Desert oasis ecotone (DOE) protects the oasis from wind and sand intrusion, thereby playing a crucial role in controlling desertification. However, there is limited knowledge about how DOE functions in windproof and sand-fixation. Therefore this study employs a three-dimensional (3D) laser scanner to monitor surface accumulation and erosion, and through field observations, collects data on wind profiles, grain size, and sand transport rates to uncover the role of DOE in aeolian sand protection.
View Article and Find Full Text PDFMov Ecol
December 2024
Institute of Biology and Environmental Science, Carl von Ossietzky Universität Oldenburg, Ammerländer Heerstraße 114-118, 26129, Oldenburg, Germany.
Background: Migratory bats perform seasonal movements between their summer and winter areas. When crossing ecological barriers, like the open sea, they are exposed to an increased mortality risk due to energetically demanding long-distance flights and unexpected inclement weather events. How such barriers affect bat migratory movements is still poorly known.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!