let g=(v,e) be a simple graph. an edge labeling f:e to {0,1} induces a vertex labeling f^+:v to z_2 defined by $f^+(v)equiv sumlimits_{uvin e} f(uv)pmod{2}$ for each $v in v$, where z_2={0,1} is the additive group of order 2. for $iin{0,1}$, let e_f(i)=|f^{-1}(i)| and v_f(i)=|(f^+)^{-1}(i)|. a labeling f is called edge-friendly if $|e_f(1)-e_f(0)|le 1$. i_f(g)=v_f(1)-v_f(0) is called the edge-f...

Since the introduction of mechanical seals in nuclear boiling water reactor (BWR) feed pumps operating with high drive ratings, keeping mechanical seal reliability high became a challenge. A problem also encountered in fossil feed pump applications using similar electrically low conductive feed water, referred to as Combined Water Treated (CWT) feed water operation. After a short number of oper...

• Chipping, sledging and hammering on metal, stone or concrete • Use of manual, pneumatic and power impact tools • Caulking, brushing and grinding • Drilling, scaling and scraping soldering and casting hot metals • Handling acids, caustics and creosoted materials • Gas welding, cutting and brazing • Drilling overhead • In environments of excessive dust • Electric arc welding and cutting, and ot...

Abstract Proportions of high- and ultra-high strength steels are constantly increasing in modern car bodies. In the press shop there uncertainties concerning application with higher than 1000MPa particularly shear cutting processes. To support steel user regarding a tool material coating wear behavior, long-term test had been carried out. The effects various conditions on damage were investigat...