نتایج جستجو برای: rail defect
تعداد نتایج: 104822 فیلتر نتایج به سال:
This report evaluates rail transit benefits based on a comprehensive analysis of urban transportation system performance in major U.S. cities. It discusses best practices for evaluating transit benefits. It finds that cities with larger, well-established rail systems have significantly higher per capita transit ridership, lower average per capita vehicle ownership and mileage, less traffic cong...
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...
ترمیم asd primum درافراد با رنج سنی متفاوت معمولا در برگیرنده عوارض کوتاه مدت و تاخیری می باشد. مابصورت مطالعه توصیفی و گذشته نگر در صدد تعیین نتایج جراحی با تکنیک اصلاح شده در بیماران با نقص (partial a-v canal defect)sdprimum در مراکز جراحی قلب کرمانشاه از سال 1373 تا مهرماه 1380 می باشیم.
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 ...
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...
در این پایان نامه، رفتار استاتیک ساختارهای آرایه ای پادهدایت vcsel، شبیه سازی و آنالیز شده است. برای تحلیل مشخصه های نوری (میدان نزدیک و دور)، گرمایی (توزیع دما) و اکتریکی (چگالی حامل) ساختار، از مدل نسبتاً جامعی که شامل معادلات موج، پخش حامل و انتقال گرما و اثرات متقابل پدیده های نوری، گرمایی و الکتریکی است، استفاده گردیده است. دو گروه از vcselهای آرایه ای پادهدایت، بررسی شده اند: آرای? تزویج ...
The formation of White Etching Layers (WELs) in rails can lead to the initiation microcracks, thus reducing service time rails. However, WEL mechanism is not yet understood. Brown (BELs) are intermediate microstructure located between parent pearlite and WEL. In this work, we use BELs as a microstructural tracer understand early stages formation. We study mechanisms an industrial R350HT rail st...
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