cat is a standard Unix utility that reads files sequentially, writing them to standard output. The name is derived from its function to concatenate files.
== History ==
cat was part of the early versions of Unix, e.g., Version 1, and replaced pr, a PDP-7 and Multics utility for copying a single file to the screen.The version of cat bundled in GNU coreutils was written by Torbjorn Granlund and Richard Stallman.
== Usage ==
The Single Unix Specification defines the operation of cat to read files in the sequence given in its arguments, writing their contents to the standard output in the s...
Uranium-235 (235U) is an isotope of uranium making up about 0.72% of natural uranium. Unlike the predominant isotope uranium-238, it is fissile, i.e., it can sustain a fission chain reaction. It is the only fissile isotope that exists in nature as a primordial nuclide.
Uranium-235 has a half-life of 703.8 million years. It was discovered in 1935 by Arthur Jeffrey Dempster. Its fission cross section for slow thermal neutrons is about 584.3±1 barns. For fast neutrons it is on the order of 1 barn.
Most but not all neutron absorptions result in fission; a minority result in neutron capture forming...
