Calculadora electrónica

La fecha de producción se ha tomado de fuentes directas existentes en el Archivo del Observatorio de San Fernando.Transcripción: "Friden 130 electronic calculator, N-30126

Calculadora electromecánica

La fecha de producción se ha tomado de fuentes directas existentes en el Archivo del Observatorio de San Fernando.Transcripción: "Friden

Washington, D.C. 20591

Specific heat release rate is the molecular-level fire response of a burning polymer. The Federal Aviation Administration (FAA) obtains the specific heat release rate of milligram samples by analyzing the oxygen consumed by complete combustion of the pyrolysis gases during a linear heating program. Dividing the specific heat release rate (W/g) by the rate of temperature rise (K/s) gives a material fire parameter with the units (J/g-K) and significance of a heat (release) capacity. The heat release capacity appears to be a true material property that is rooted in the chemical structure of the polymer and is calculable from additive molar group contributions. Hundreds of polymers of known chemical composition have been tested to date, providing over 40 different empirical molar group contributions to the heat release capacity. Measured and calculated heat release capacities for 80 polymers agree to within 15%, suggesting a new capability for predicting flammability from polymer chemical structure. 17. Key Words Thermochemistry, Polymer flammability, Group contributions, Heat release, Fire, Combustion, Pyrolysis, Kinetics 18. Distribution Statement This document is available to the public through the National Technical Information Service (NTIS), Springfield, Virginia 22161