Today’s railway transport is built upon high-performance infrastructure. Cost-effective yet sustainable infrastructure presumes tracks with a precise and durable geometry. At ballasted tracks, the geometry created restored through tamping machines, which position track panel compact ballast beneath sleepers. It commonly agreed that compaction plays an important role in long-term stability of tr...

Concrete sleepers have been widely used throughout the world as an alternative for timber sleepers. In North America, heavy-haul railroads have increased their use of concrete sleepers in recent years for a variety of factors. According to an international survey conducted by researchers at the University of Illinois at Urbana-Champaign (UIUC), railroad industry representatives consider center ...

PURPOSE The aim was to evaluate the anterior and posterior corneal topographic characteristics of three patients with posterior polymorphous corneal dystrophy (PPCD) using a rotating Scheimpflug camera combined with a Placido disc system (Sirius, CSO, Italy). CASE REPORTS Two children with unilateral PPCD and a 53-year-old woman with bilateral PPCD were diagnosed by the presence of vesicles a...

The practice of construction and operation railroads in the Arctic zone shows that greatest share track deformations occurs summer period during transition soils subgrade from frozen state to thawed state. Wetting, freezing-thawing, vibrodynamic effects trains have influence on properties clay composing railroad bed. A model a sub-tie base stabilized by geosynthetic materials is given. material...