TY JOUR TI HEAT OF COMBUSTION AND COMBUSTIBILITY COEFFICIENT: RELATIONSHIP BETWEEN FIRE HAZARD CHARACTERISTICS OF A SUBSTANCE KW combustibility coefficient KW physical meaning KW heat of combustion KW Hess's law KW fire hazard JO Problems of risk management in the technosphere AU Korobejnikova, E.G. AU Kozhevin, D.F. PY 2026 IS 2025 PB Saint-Petersburg University of State Fire Service of Emercom of Russia