A subset of vertices in a graph is called a dissociation set if it induces a subgraph with vertex degree at most 1. A dissociation set D is maximal if no other dissociation set contains D. The complexity of finding a dissociation set of maximum size in line graphs and finding a maximal dissociation set of minimum size in general graphs is considered.

N atom density is determined in pulsed RF 27 MHz nitrogen plasma at the pressures ranging from 1.5 to 5 torr and effective discharge currents ranging from 80 to 140 mA. From time resolved measurements of fluorescence of second and first positive systems of nitrogen in after-glow the density is calculated using simple kinetic model of nitrogen after-glow. Calculated density of N atoms is in rang...

The traditional grinding technology of ball mill has many problems, such as high energy consumption, unable to maintain the original crystal shape, and it is difficult obtain quality purity ultrafine powder. high-pressure water jet mineral dissociation a new which developed in response these requirements. experiment shows that strong ability grinding. With increase velocity, crushing effect mor...