Chapter 18 Flashcards
Fires and explosions result of
combustion
Combustion
Reaction of fuel with oxygen
products of combustion
CO2
water
energy
Exothermic
chemical reaction releases energy as product
Endothermic
required input of energy
Activation energy
reaction require some input of energy for initial on
fire tetrahedron
oxygen
heat
fuel
chain reaction
flash point
lowest temp allow liquid produce a flammable vapor
flame point
lowest temp that will sustain combustion
flashback
fire burned with limited supply of oxygen then suddenly ventilated
Types of fire
natural
accidental
deliberate
first step of analysis
isolate the accelerant from matrix
second step
determine nature of accelerant
GC or MS
Headspace
sampled with gaslight syringe and injected into GC
passive adsorption
container or strip coated with charcoal places in suspected container
active absorption
charcoal tubes inserted and air pumped through tubes into container
Solid Phase micro extraction
inserting fiber with adsorbent into headed container
GC
Mass spectrometry
individual components of residues
blast pressure
escaping gases
pressure wave
vacuum created
low explosives
below 3,280 fps
high explosives
3,280 psi and up
high order explosion
at least near its maximum theoretical detonation velocity
low order explosion
less than optimal efficiency
low explosive trains
two step
fuse black powder used to ignite smokeless powder
