FRSC1030 Foundations of Forensic Science Chapter 14

Blasting cap

A small device that initiates the detonation of a larger explosive charge,

Blast wave

Also called a pressure wave or overpressure, a supersonic wave that propagates outward from an explosion of other rapid energy release event.

Brisance

The ability of an explosive to shatter the container and other objects, or its destructive fragmentation capability.

Deflagration

A type of combustion that occurs at subsonic speed, a rapid burning process that spreads through thermal conductivity, where heat from the burning material ignites nearby colder material.

Detonation

A type of combustion that occurs at a supersonic speed, creating a powerful shock wave. 

Detonation cord

A flexible linear explosive with a cord of high explosive encased in a protective jacket, used for drilling, seismic studies, and demolition.

Detonation velocity

The speed at which a shock wave travels through an explosive material as it detonates.

Explosion

A sudden, rapid, and often violent release of hot, expanding gases, created by the confinment of gases and an increase in pressure until the container breaks.

Flame front

The leading edge of a combustion reaction where unburned gas meets heat and converts into combustion products, or the boundary between unburned fuel and air and the hot, burned gases.

Homemade explosives (HME)

Explosive compounds, such as nitroglycerin (NG), that are improvised and made from simple ingredients.

Improvised explosive devices (IEDs)

A homemade bomb constructed and deployed in ways other that in conventional military action, often using non-military components (5 main components: power source, initiator, explosive, switch, fragmentation), such as a pipe bomb.

Linear burn rate

The distance the flame front covers over time, used to characterize the speed of a combustion or thermal decomposition reaction.

Molecular explosive

An explosive in which the fuel and an oxidant are in the same molecule, such as nitroglycerin (NG) which contains CO2, CO, N2 and O2, and sufficient oxygen to sustain the reaction.

Overpressure

A blast wave with a significant amount of pressure, causing a pressure spike above normal atmospheric pressure, caused by an explosion.

Pipe bomb

A common type of IED encountered in law enforcement, because of their easy creation, consisting of a pipe secured at both ends by threaded caps to provide containment, filled with gunpowder.

Pressure wave

Also called a blast wave or overpressure, a supersonic wave that propagates outward from an explosion of other rapid energy release event.

Pushing power

The power of an explosive device, defined by the power of the blast wave it creates.

Shock wave

A wave that exceeds the speed of sound.

Shrapnel

Pieces of the container of an explosive that get carried out by the expanding gases.

Standoff detection

A technique for remotely identifying chemical, biological, or explosive threats from a safe distance, through non-contact optical (such as X-rays) and spectroscopic methods, or detecting vapors given off by explosive.