Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

ABC Certification > Fire and Explosives > Flashcards

Fire and Explosives Flashcards

1
Q

Combustion

A

Chemical reaction that results in fire and/or explosions

Reaction of fuel and oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Products of complete combustion

A

Carbon dioxide, water, energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Activation energy

A

Required energy to start a chemical reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Arson

A

Fires that are deliberately set with criminal intent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

4 components of the fire tetrahedron

A

Oxygen, fuel, heat, chain reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Ignition temperature

A

Temperature needed to start a fire- dependent on the fuel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Flash point

A

Temperature with enough energy to convert enough of the liquid fuel to a vapor to support combustion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Flame point

A

A higher temperature than the flash point that will sustain combustion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Incomplete combustion

A

When there are limited reactants in the combustion equation (usually oxygen)
Results in smoke

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Smoke

A

Product of incomplete combustion

Made up of carbon particles (soot), unburnt and partially burnt gases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Flashback

A

If there is not enough oxygen present, ventilation of the space (opening a door or window) will increase oxygen and result in an explosive fire

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Accelerants

A

Fuels that are easily vaporized and support combustion, highly exothermic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Incendiary fire

A

Intentionally set fire (not necessarily arson)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Three types of fires (forensic standpoint)

A

Natural, accidental, deliberate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Natural fire

A

Occur without human input (ex. lightning strike fires)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Accidental fires

A

Fires that were probably preventable, occur without criminal intent (ex. dryer lint fire)

17
Q

Characteristics present at a point of origin in a fire

A 
Low burning (arson/deliberate)
 V patterns of smoke around the point of origin
Wood charring will be greatest near it 
Spalling of plaster or concrete
Material distortion
Soot and smoke staining
18
Q

Indications of an arson fire

A

The presence of an accelerant
Elimination of natural or accidental causes
Fire trails (from accelerant)
Multiple points of origin

19
Q

Fire scene evidence packing

A

Airtight containers

20
Q

Henry’s law in regards to headspace analysis

A

At equilibrium, depending on the vapor pressure, there will be a certain amount of the volatile substance in vapor form and a certain amount in the residue (evidence)

21
Q

Absorption methods in headspace analysis

A

Passive and active
Passive- charcoal strip is added and either left overnight or heated. The charcoal strip is then put into a solvent to extract the accelerant
Active- two holes in the paint can with charcoal tubes, one pushing in air. This upsets the equilibrium and more accelerant will vaporize and be pushed out the second carbon tube

22
Q

SPME

A

Solid-phase micro extraction
A absorbent needle/fiber is inserted into the fire residue container. The fiber can then be injected directly into the GC because the heat at the inlet will rapidly elute the accelerant into the mobile phase stream

23
Q

Weathering

A

Describes the degradation of an accelerant due to heat or other environmental factors

24
Q

Conflagration

A

Very rapid combustion (think spark plug in engine)

25
Q

Instantaneous combustion or detonation

A

More rapid than conflagration, occurs when the oxygen and fuel are chemically combined into a single molecule

26
Q

How are explosives categorized?

A

Low, high

By detonation velocity

27
Q

Three primary effects of an explosion

A

Blast pressure, fragmentation, thermal/heat effects

28
Q

Blast pressure

A

Escaping gases travel at high speeds, compressing gases and surrounding air, exerting pressure, causes vacuum
Negative pressure phase- “reverse” blast effect, once the blast wave dissipates, the vacuum must be filled in and the air will rush back towards the bomb seat

29
Q

Bomb seat

A

Origin of the explosion

30
Q

Fragmentation effects

A

Bomb casing can shatter and the pieces will be propelled away with force, shrapnel may cause fragmentation, blast may break objects

31
Q

Thermal effects

A

Least damaging, heat produced in explosion will travel outwards

32
Q

Low explosives

A

Oxygen is physically mixed with the fuel, speed of explosion is slower, push rather than shatter
Examples- smokeless powder, nitrocellulose

33
Q

High explosives

A

Faster detonation rates, shatter objects and destroy them

34
Q

Initiating/Primary high explosives

A

Very powerful and very sensitive

Ex- nitroglycerine

35
Q

Non initiating/Secondary high explosives

A

Not sensitive, take a large effort for detonation, easily transported
Ex- C4

36
Q

Low- and High-order explosions

A

Nothing to do with the type of explosive, but rather the efficiency of the explosion

ABC Certification (14 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions