PHY 121 Lecture Notes - Lecture 13: National Ambient Air Quality Standards, Thermal Energy, Density
11 Dec 2016
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Document Summary
Energy conversion steps: chemical to thermal to mechanical to electrical. Chemical energy is made thermal through a boiler. Thermal energy is made mechanical through a turbine. To get the total energy you have to multiple the efficiencies of each step. Smokestacks are actively filtered but still 1% of particulate matter escapes. Particulates are mostly spherical so diameter is used to classify them. Mass density p (rho) = measure of the amount of a mass in a given volume. [mass density p (rho)] = [mass (m) in kilograms] divided by [volume (v) in meters cubed] Particulates are often measured as a concentration (density in 1 cubic meter of air). Typical concentrations are between 10 micrograms per meter cubed to 200 micrograms per meters cubed (heavily polluted). We lose particle size info (proportion of size is approximately the same. Fewer massive particles, approximately 95% of all particulate mass. Particulates < 2. 5 micrometers are damaging to the people and the environment.
