The Sand Track

Investigation of the Influences of Track Superstructure Parameters on Ballasted Railway Track Design

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...

Circles in the sand.

Introduction F. Jacob (Paris, France), co-creator of the replicon hypothesis and the operon model, opened the workshop with his memories of a summer 40 years ago. In the early morning, he and Sydney Brenner would accompany their eight children to the beach so that the ladies of the two families could sleep. As the two men talked, they illustrated their thoughts by drawing models in the sand. Th...

Playing in the sand.

Children were a common theme for the impressionist painter Mary Cassatt. Her "Children on the Beach" depicts a placid scene around the turn of the century. With buckets and small shovels, two little girls in beach dresses, one with a sun bonnet, make an attempt to change the sandy landscape; in the background sailboats float serenely in the calm waters. On viewing the painting, we feel that eve...

Radiation track and DNA damage

Mammals [of the Sand Hills]