TY JOUR TI FLAMMABLE PARTICLES GENERATED DURING CUTTING OF INORGANIC BUILDING MATERIALS ABRASIVE CUTTING DISCS ANGLE GRINDERS KW friction sparks KW stone inorganic material KW fire risk KW angle grinder JO Problems of risk management in the technosphere AU Popov, A.V. AU Claptyuk, I.V. AU Kondrat, S.A. PY 2014 IS 2014 PB Saint-Petersburg University of State Fire Service of Emercom of Russia