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Return to Terminology
N
- Napalm
- A gasoline thickener.
- National Fire Protection Association
- Standards for explosive materials and ammonium nitrate issued
by the National Fire Protection Association.
- National Safety Council (NSC)
- A nonprofit organization chartered by Congress to provide a
regular information service on the causes of accidents and ways to prevent them.
- Natural Gas
- Natural gas, natural mixture of flammable gases found issuing
from the ground or obtained from specially driven wells. Largely a mixture of Hydrocarbons, natural gas is usually 80 to 95% Methane. The composition
varies in different localities, and minor components may include carbon dioxide, nitrogen,
hydrogen, carbon monoxide, and helium. Often found with Petroleum,
natural gas also occurs apart from it in sand, sandstone, and limestone deposits. Natural
gas began to be used as an illuminant and a fuel on a large scale in the late 19th
century, when pipelines were built to provide it to large industrial cities. Liquified
natural gas (LNG) is natural gas that has been cooled and pressurized to liquify it for
convenience in shipping and storage.
- Neon
- (Ne), gaseous element, discovered in 1898 by William Ramsay
and M.W. Travers. A colorless, odorless, and tasteless inert gas, it emits a bright-red
glow when conducting electricity in a tube. Neon is used in advertising signs, Lasers, Geiger counters, Particle Detectors, and high-intensity
beacons. Liquid neon is a cryogenic refrigerant.
- Nerve Gas
- G-Series War Gases.
- Neutral Burning
- The burning of a propellant grain in such a manner that the
exposed surface area remains constant as burning progresses.
- Neutral Geometry
- A propellant grain configured in such a manner that the
exposed surface area remains constant as burning progresses.
- Neutron
- An uncharged Elementary,
discovered by James Chadwick in 1932, of slightly greater mass than the Proton. The stable isotopes of all elements except hydrogen and
helium contain within the nucleus a number of neutrons equal to or greater than the number
of protons. The preponderance of neutrons becomes more marked for very heavy nuclei. A
neutron bound within the nucleus may be stable. A nucleus with an excess of neutrons,
however, is radioactive; the extra neutrons (as well as any free neutrons not bound within
a nucleus) convert by beta decay ( Radioactivity) into
a proton, an electron, and an antineutrino. The neutron and the proton are regarded by
physicists as two aspects, or states, of a single entity, the nucleon. The antineutron,
the neutron's antiparticle ( Antimatter), was discovered
in 1956.
- Newton, Sir Isaac
- Sir Isaac Newton, 1642–1727, English mathematician and
natural philosopher (physicist); considered by many the greatest scientist of all time. He
was Lucasian professor of mathematics (1669–1701) at Cambridge University. Between
1664 and 1666 he discovered the law of universal Gravitation,
began to develop the Calculus, and discovered that white
light is composed of every color in the Spectrum. In his
monumental Philosophiae naturalis principia mathematica {Mathematical Principles of
Natural Philosophy} (1687), he showed how his principle of universal gravitation explained
both the motions of heavenly bodies and the falling of bodies on earth. The Principle
covers Dynamics (including Newton's three laws of Motion), Fluid mechanics, the
motions of the planets and their satellites, the motions of the comets, and the phenomena
of tides. Newton's theory that Light is composed of particles
— elaborated in his Opticks (1704) — dominated optics until the 19th cent., when
it was replaced by the wave theory of light; the two theories were combined in the modern Quantum theory. Newton also built (1668) the first reflecting
telescopeE, anticipated the calculus of variations, and devoted much energy towards
alchemy, theology, and history. He was president of the Royal Society from 1703 until his
death.
- NG
- Nitroglycerin.
- Nitric Acid
- Chemical compound (HNO3), colorless, highly
corrosive, poisonous liquid that gives off choking fumes in moist air. It is miscible with
water in all proportions. Commercially, it is usually available in solutions of 52% to 68%
nitric acid in water. Solutions containing over 86% nitric acid are commonly called fuming
nitric acid. Nitric acid is a strong oxidizing agent. It reacts with metals, oxides, and
hydroxides, forming nitrate salts.
- Nitrous Oxide
- Chemical compound (N2O), colorless gas with a
sweetish taste and odor. Although it does not burn, it supports combustion because it
decomposes into oxygen and nitrogen when heated. A major use is in dental anesthesia. It
is often called laughing gas because it produces euphoria and mirth when inhaled in small
amounts.
- Nitrocellulose
- Explosive substance formed by the nitration of cotton, or some
other form of cellulose. Used as the base of most U.S. propellants. Specific grades of
nitrocellulose ( Pyrocellulose or Guncotton)
depend on the degree to which the cellulose is nitrated.
- Nitrocotton
- Guncotton.
- Nitrogen
- (N), a gaseous element, discovered by Daniel Rutherford in
1772. Nitrogen is a colorless, odorless, tasteless, diatomic gas that is relatively
inactive chemically; it occupies about 78% (by volume) of dry air. Its chief importance
lies in its compounds, which include Nitrous oxide, Nitric Acid, Ammonia, many Explosives,
Cyanides, fertilizers, and proteins. Nitrogen is present in the protoplasm of all living
matter; it and its compounds are necessary for the continuation of life.
- Nitrogen Mustard Gases
- Group of blister gases similar to mustard gas with varying
chemical properties and little or no odor; gases affect eyes, nose and lungs.
- Nitroglycerin
- An explosive chemical compound used as a sensitizer in
dynamite and represented by the empirical formula C3H5N3O9.
Yellow oil. Detonation velocity, confined: 7600 m/s = 25,000 ft/s at r = 1.59 g/cm3.
Oxygen balance: 13.5%, nitrogen content: 18.50%, volume of detonation gases 782 l/kg. On
old boxes of dynamite it may appear as white or light gray crystals.
- Nitroglycerne
- Nitrated ester of glycerol in which the OH radicals are
replaced by N02; used as primary base of British propellants and as
gelatinizing agent of U.S. propellants but not used as primary base of U.S. propellants
because its high flame temperature accelerates bore erosion.
- Nitroguanidine (Nitrated Aminomethanamidine):
- Used as an additional base of propellant; used as a "cool
propellant" because of its low flame temperature which does not erode gun bores or
produce as much luminous flash as single (nitrocellulose) propellants.
- Nitromethane
- Nitromethane is sparingly soluble in water. The compound is of
industrial interest as a solvent rather than as an explosive. Its technical synthesis
involves nitration of methane with nitric acid above 400°C
(750°F) in the vapor phase.
- It was used in the USA for underground model explosions
(“Pre-Gondola”), in preparation for the Nuclear Charge
technique. Nitromethane was also employed in stimulation blasting in oil and gas wells.
PLX (Picatinny Liquid Explosive) is a mixture of nitromethane with 5%
ethylenediamine and is used to clean up mine fields.
- No. 8 Test Cap
- Institute of Makers of Explosives No. 8
Test Detonator.
- Nobel-Abel Equation
- Derivation of perfect gas law - P max equals FD/1-aD where P
rnax equals maximum pressure, F equals force factor in psi - cc/gD equals loading density
in g/cc and a equals co-volume factor in cc/g. Used in interior ballistic computations.
- No-Fire Current
- Maximum current which can be continuously applied to a
bridgewire circuit without igniting the prime material. (Note that continued application
of this current may degrade the prime and "dud" the unit.)
- Non-conventional Entry / Breach Point
- A non-normal point of entry into the target area, which may
include: air- conditioning ducting, service access, sewers or proceeding through a window,
wall, ceiling or floor.
- Non-Delay Fuze
- Fuze that functions as a result of inertia of firing pin (or
primer) as missile is retarded during penetration of target. The inertia causes the firing
pin to strike the primer (or primer the firing pin) initiating fuze action. This type of
fuze is inherently slower in action than the superquick or instantaneous fuze, since its
action depends upon deceleration (retardation) of the missile during penetration of the
target.
- Nonelectric Detonator
- A detonator that does not require the use of electric energy
or safety fuse to function.
- Nonhygroscopic
- Does not absorb moisture from the air.
- Nonsparking Metal
- A metal that will not produce a spark when struck with other
tools, rock, or hard surfaces.
- Normal Charge
- Propelling charge employing a standard amount of propellant to
fire a gun under ordinary conditions, as compared with a reduced charge or a supercharge
used in special circumstances.
- Normal Curve
- The idealized distribution of an infinite number of
observations equally divided between favorable and unfavorable.
- Normal Force
- Component of air resistance perpendicular to the axis of the
projectile in the plane of yaw (exterior ballistics). Any force perpendicular to a given
line or surface (general).
- Normal Impact
- Striking of a projectile against a surface that is
perpendicular to the line of flight of the projectile.
- Nose Spray
- Spray.
- Nuclear Energy
- Nuclear energy is the energy stored in the nucleus of an Atom and released through fission, fusion, or Radioactivity. In these processes a small amount of mass,
equal to the difference in mass before and after the reaction, is converted to energy
according to the relationship E = mc2, where E is energy, m mass, and c the
speed of light ( Relativity). In fission processes, a
fissionable nucleus absorbs a neutron, becomes unstable, and splits into two nearly equal
nuclei. In fusion processes, two nuclei combine to form a single, heavier nucleus. Fission
occurs for very heavy nuclei, while fusion occurs for the lightest nuclei. Nuclear fission
was discovered in 1938 by Otto Hahn and Fritz Strassman, and was explained in 1939 by Lise
Meitner and Otto Frisch. Fission energy can be obtained by bombarding the fissionable
isotope Uranium-235 with slow neutrons in order to split it.
Because this reaction releases an average of 2.5 neutrons, a chain reaction is possible,
provided at least one neutron per fission is captured by another nucleus and causes a
second fission. In an Atomic Bomb
the number of neutrons producing additional fission is greater than 1, and the reaction
increases rapidly to an explosion. In a Nuclear Reactor,
where the chain reaction is controlled, the number must be exactly 1 in order to maintain
a steady reaction rate. Uranium-233 and Plutonium-239 can
also be used but must be produced artificially. Moreover, the fuel for fusion reactors,
deuterium, is readily available in large amounts. Temperatures greater than 1,000,000°C
are required to initiate a fusion, or thermonuclear, reaction. In the Hydrogen
Bomb such temperatures are provided by the detonation of a fission bomb.
Sustained, controlled fusion reactions, however, require the containment of the nuclear
fuel at extremely high temperatures long enough to allow the reactions to take place. At
these temperatures the fuel is a Plasma, and magnetic fields
have been used in attempts to contain this plasma. To produce fusion energy, scientists
have also used high-powered laser beams aimed at tiny pellets of fission fuel. Once
practical controlled fusion is achieved, it will have great advantages over fission as a
source of energy.
- Nuclear Physics
- The study of the components, structure, and behavior of the
nucleus of the Atom. It is especially concerned with the nature
of matter and Nuclear Energy. The subject is commonly divided
into three fields: low-energy nuclear physics, the study of Radioactivity;
medium-energy nuclear physics, the study of the force between nuclear particles; and
high-energy, or particle, physics, the study of the transformations among subatomic
particles in reactions produced in a Particle Accelerator. Elementary Particles.
- Nuclear Reactor
- A device for producing Nuclear Energy
by controlled nuclear reactions. It can be used for either research or power production.
The reactor is so constructed that the fission of atomic nuclei produces a self-sustaining
nuclear chain reaction, in which the produced neutrons are able to split other nuclei. A
fission reactor consists basically of
- (1) a fuel, usually uranium or plutonium, enclosed in
shielding;
- (2) a moderator—a substance such as graphite, beryllium, or heavy water—that slows down the
neutrons so that they may be more easily captured by the fissionable atoms; and
- (3) a cooling system that extracts the heat energy produced.
- The fuel is sometimes enriched—i.e., its concentration of
fissionable isotopes is artificially increased—to increase the frequency of neutron
capture. The breeder reactor is a special type of reactor that produces more fissionable
atoms than it consumes by using surplus neutrons to transmute certain nonfissionable atoms
into fissionable atoms. The design of fusion reactors is still in an experimental stage
because of the problems involved in containing the plasma fuel and attaining the high
temperatures needed to initiate the reaction.
- Nuclear Winter
- A controversial predicted effect of a nuclear war. The theory
holds that the dust and particles thrown into the atmosphere by a massive exchange of
nuclear weapons would block a large percentage of sunlight, resulting in global cooling,
leading to severe winterlike weather and killing all crops.
- Nutation
- A small periodic oscillation about the motion of precession.
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