منابع مشابه
On the dynamics of European two–axle railway freight wagons
The design of European two–axle freight wagons can be traced back to the 1890’es. It has been and still is widely used in Europe because it is simple, rugged and cheap in price and maintenance. The internationally approved suspension for two–axle freight wagons in Europe is known as the UIC standard suspension (see Fig. 1). Each wagon has four of these suspensions. They consist of a leaf spring...
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Premature failure of rail axle bearings causes a significant increase in train operating costs and can impact train safety. A new on-board condition monitoring approach provided by Perpetuum Ltd is fitted on passenger trains to provide the operator with real-time information on bearing health. This new technology allows the detection of early bearing damage. This paper reports an initial study ...
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In This Issue In This Issue Saying NO to muscular dystrophy ccording to the prevailing model for Duchenne muscular dystrophy (DMD) pathogenesis, a lack of dystrophin protein makes muscle cells susceptible to mechanical damage, leading to muscle breakdown. On page 123, Wehling et al. suggest that the major damage in DMD may actually be caused by a secondary consequence of dystrophin loss: destru...
متن کاملThe Fragile Breakage versus Random Breakage Models of Chromosome Evolution
For many years, studies of chromosome evolution were dominated by the random breakage theory, which implies that there are no rearrangement hot spots in the human genome. In 2003, Pevzner and Tesler argued against the random breakage model and proposed an alternative "fragile breakage" model of chromosome evolution. In 2004, Sankoff and Trinh argued against the fragile breakage model and raised...
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Understanding fluctuation-induced breakages in polymers has important implications for basic and applied sciences. Here I present for the first time an analytical treatment of the thermal breakage problem of a semi-flexible polymer model that is asymptotically exact in the low temperature and high friction limits. Specifically, I provide analytical expressions for the breakage propensity and ra...
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ژورنال
عنوان ژورنال: Scientific American
سال: 1877
ISSN: 0036-8733
DOI: 10.1038/scientificamerican06161877-1200asupp