In this research, the structural behavior of timber and concrete sleepers in a standard railway turnout is evaluated, in the case of raising speed. In approaching this evaluation, current practices in the structural analysis of sleepers are surveyed and then, the sensitivity analysis with ABAQUS software is made based on selected criteria (bending and shear stresses as well as contact pressure)...

Abstract Dynamic wheel–rail contact forces induced by a severe form of wheel tread damage have been measured impact load detector during full-scale field tests at different vehicle speeds. Based on laser scanning, the three-dimensional geometry is employed in simulations dynamic vehicle–track interaction to calibrate and verify simulation model. The relation between magnitude various operationa...

Miles K (2011) Using attachment theory in mentoring. Nursing Times; 107:

The main design criteria of ballasted railway tracks include rail deflections, rail bending stresses, rail wheel contact stresses, sleeper bending moments and ballast sleeper contact pressures. Numerous criteria have been defined for the design of ballasted railway tracks owing to the various mechanical properties of track components and their complex interaction. Therefore, railway track desig...

AIM To examine sleep quality and its determinants among people with type 2 diabetes mellitus (T2DM). METHODS This is a cross-sectional study conducted among diabetic patients referring to Ardabil diabetes clinic in Northwest of Iran. Information on sleep quality was collected using Pittsburg Sleep Quality Index (PSQI). A questionnaire was used to collect data on sociodemographic lifestyle fac...

The role of the media in the creation of distrust is much debated in political communication. Will negative news, for example, relentless attacks on political authorities, result in political cynicism or in a stimulation effect? By and large the media may stimulate political participation,but it is less clear when negative news will nullify this effect. Negative news may not only have short-ter...

An improved spatial vehicle–track–bridge interaction system considering the unsupported track is proposed using virtual work principle. When fails to be supported due defects under track, corresponding bridge–rail connection coupled matrix should removed. Using dynamic model, a novel numerical analysis of unilateral and bilateral sleepers in bridge subgrade carried out. The results indicate tha...

A constitutive model based on plasticity theory with a non-associative flow rule has been developed. The model is formulated in terms of sleeper displacements and forces, and includes hardening and softening controlled by irreversible transversal (lateral and longitudinal) sleeper displacements. The model has been calibrated using results from lateral and longitudinal ballast resistance tests c...