Ballast as a part of the railway system plays an important role in the operation of the railways and also has a great impact on repair and maintenance activities. Hence most of the repair and maintenance activities in traditional railway systems are due to the defections in the ballast layer and therefore most of the maintenance budget is spent on repairing these defects. These repair and maint...

abstract  background: the essential constituents of cements like lime, silica and alumina are derived from earth’s crust in which radioactive elements like uranium, thorium etc are also present in varying amounts almost everywhere. these two elements are considered as the parent elements of uranium and thorium radioactive decay series in which radon and thoron are produced respectively as decay...