In this paper the efficiency of lightning shielding provided by single overhead ground wire mounted atop a double circuit self-supported 220 kV lattice power transmission line tower with total height 37.115 m was examined. According to electro-geometric concept, each phase conductor has an area where does not provide full protection against direct strike. The width unprotected depends on design...

reaction to fire of fire-retarded rigid pur foams and two types of metal faced rigid polyurethane foam core sandwich panel was evaluated by using cone calorimeter test method. the tests were carried out in various radiative heat fluxes from 15 to 75 kw/m2. the radiation rate effect on reaction to fire parameters, including time to ignition (tti), peak of heat release rate (prhr), total heat rel...