نتایج جستجو برای: guard rail
تعداد نتایج: 17006 فیلتر نتایج به سال:
Railway infrastructure monitoring is a vital task to ensure rail transportation safety. A rail failure could result in not only a considerable impact on train delays and maintenance costs, but also on safety of passengers. In this article, the aim is to assess the risk of a rail failure by analyzing a type of rail surface defect called squats that are detected automatically among the huge numbe...
Rail wheel squeal on curves in rail track is a source of potential noise annoyance to residents adjacent to rail lines. For one private rail freight operator, wheel squeal was causing repeated complaints from neighbours. Wheel squeal can be caused by the wheel-tyre to rail-top interaction and the wheel flange interaction with the gauge face of the rail (more like a screech). This paper describe...
Abstract: To ensure the rail transportations safety, evaluation of fatigue behavior of the rail steel is necessary. High cycle fatigue behaviour of a rail steel was the subject of investigation in this research using fracture mechanics. Finite element method (FEM) was used for analyzing the distribution of the stresses on the rail, exerted by the external load. FEM analysis showed that the ...
we consider a dynamic domination problem for graphs in which an infinitesequence of attacks occur at vertices with guards and the guard at theattacked vertex is required to vacate the vertex by moving to a neighboringvertex with no guard. other guards are allowed to move at the same time, andbefore and after each attack and the resulting guard movements, the verticescontaining guards form a dom...
expansin proteins are a type of cell-wall loosening proteins which able to cell wall expansion in ph-dependent manure without hydrolyze of main cell wall structures. the arabidopsis expa1 exhibit guard cell specific expression and trigger the stomatal movements. the objectives of this study were to transfer the atexpa1 gene into tobacco plants and evaluate their phonotypic effects on transforme...
At present, high-speed rail is used only as a mode of passenger transport. Yet, the acceleration of logistics and freight transport flows could be compatible with high-speed rail capabilities. This article examines the experiences, literature and prospects of high-speed rail for freight. It uses three hypotheses to evaluate the development of freight high-speed rail services in Europe. The arti...
Currently most modern dc rapid transit systems around the world use running rails or a negative rail as the negative return circuit for the dc traction current. These rails are intentionally kept ungrounded from ground (earth) by using insulating material between the rail and earth to minimize dc stray current. This configuration of return current rail develops varying voltage with respect to g...
The primary mechanisms playing a role in the dynamic wheel–rail response to rail weld irregularities in a ballasted track are pointed out. The concept of P1 and P2 forces for metallurgical rail welds, introduced in a first paper [1] concerning the present research, is further elaborated. The dynamic wheel–rail response is simulated for a number of geometrical rail weld measurements. Results sho...
In 2014, more than 43 cities in China were racing to construct their urban rail systems (including metro and light rail systems), recognizing that an urban rail system will be a good solution to the tough problems that they are faced with, including traffic congestion and PM2.5 air pollution. On 22 August 2012, the first electric double-layer capacitor (EDLC) energy storage-type rail vehicle in...
Evaporation of water from the guard cell wall concentrates apoplastic solutes. We hypothesize that this phenomenon provides two mechanisms for responding to high transpiration rates. First, apoplastic abscisic acid is concentrated in the guard cell wall. Second, by accumulating in the guard cell wall, apoplastic sucrose (Suc) provides a direct osmotic feedback to guard cells. As a means of test...
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