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Return to Terminology
E
- EBW (Exploding Bridge Wire)
- A bridgewire designed to be exploded by a high energy
discharge rather than being heated by applied power.
- EBW Cap
- Exploding bridge wire cap. Requires a special, high energy
blasting machine to initiate EBW caps.
- E.C. Blank Fire
- E.C. Smokeless Powder.
- E.C. Smokeless Powder
- Orange or pink explosive powder, resembling coarse sand. It is
used as a charge in small arms, in blank cartridges. Also called blank-fire powder or E.C.
Blank Fire.
- Eccentricity
- Distance from center line to center of gravity of projectile.
- Echo
- Reflection of a sound wave back to
its source in sufficient strength and with a sufficient time lag (at least 0.1 sec) to be
separately distinguished by the human ear.
- EED (Electro-Explosive Device)
- Any cartridge, squib, igniter, etc., which is initiated by an
electric current.
- EFF
- Acronym for explosive forged fragment.
- EFP
- Acronym for both explosive formed projectile, explosive forged
projectile.
- Ejection Capsule
- 1) In an aircraft or manned spacecraft, a detachable
compartment serving as a cockpit or cabin which may be ejected as a unit and parachuted to
the ground.
- 2) In an artificial satellite, probe or unmanned spacecraft, a
box-like unit usually containing recording instruments or records of observed data which
may be ejected and returned to earth by a parachute or other deceleration device.
- Elastic Strength Pressure
- The computed internal gas pressure in a gun which, at the
section under consideration, will stress the metal in some layer of the wall tangetially,
up to the minimum elastic limit which is prescribed for the metal from which the member is
made.
- Electric And Magnetic Units
- Units used to express the magnitudes of various quantities in
electricity and magnetism. Three systems of such units, all based on the Metric System, are commonly used. One of these, the mksa-practical
system, is defined in terms of the units of the mks system and has the Ampere
of electric current as its basic unit. The units of this system - the Volt,
Ohm, Watt, and farad - are those
commonly used by scientists and engineers to make practical measurements. The two other
systems, now being gradually abandoned, are both based on the cgs system. Electrostatic
units (cgs-esu) are defined in a way that simplifies the description of interactions
between static electric charges; there are no corresponding magnetic units in this system.
Electromagnetic units (cgs-emu), on the other hand, are defined especially for the
description of phenomena associated with moving electric charges, i.e., electric currents
and magnetic poles.
- Electric Blasting Circuit
- An electric circuit containing electric detonators and
associated wiring; Series Blasting Circuit, Parallel Blasting Circuit, and Series
in Parallel Blasting Circuit.
- Electric Circuit
- An electric circuit can be described as an unbroken path along
which an electric current may flow. A simple circuit consists of a voltage source, such as
a battery ( Cell, in electricity) or a Generator,
whose terminals are connected to those of a circuit element, such as a Resistor, through which current can flow. More complex circuits
include additional sources or elements and perhaps Switches,
so interconnected that, when appropriate switches are closed, each element is included in
a closed path that also contains a source. Series, parallel, and non-series-parallel
connections are illustrated in the figure. The effective Resistance
of two series-connected resistors is the sum of the individual resistances. The effective
conductance (reciprocal of resistance) of two parallel-connected resistors is the sum of
the individual conductances.
- Electric Detonator
- A detonator designed for, and capable of, initiation by means
of an electric current.
- Electric Primer
- Metallic device containing a small amount of sensitive
explosive or charge of black powder which is actuated by energizing an electric circuit.
It is used for setting off explosive or propelling charges.
- Electric Squib
- Commercial flash-fuze device for electrical firing of burning
type munitions such as smoke pots. It consists essentially of a small tube sealed with
sulfur, crimped rubber or asphalt containing a small charge
of powder compressed around a fine resistance wire. There are three types: open end;
flash-vented; and closed end.
- Electrical Storm
- An atmospheric disturbance characterized by intense electrical
activity, producing lightning strikes and strong electric and magnetic fields.
- Electricity
- Electricity describes a class of phenomena arising from the
existence of charge. According to modern theory, most Elementary
Particles of matter possess charge, either positive or negative. Two particles of
like charge, both positive or both negative, repel each other; two particles of unlike
charge are attracted ( Coulomb’s Law). The electric Force between two charged particles is much greater than the
gravitational force between the particles. Many of the bulk properties of matter are
ultimately due to the electric forces among the particles of which the substance is
composed. Materials differ in their ability to allow charge to flow through them. Those
that allow charge to pass easily are conductors ( Conduction),
whereas those that allow extremely little charge to pass through are called insulators ( Insulation), or Dielectrics. A
third class of materials, called Semiconductors, is
intermediate. Electrostatics is the study of charges, or charged bodies, at rest. When a
positive or negative charge builds up in fixed positions on objects, certain phenomena can
be observed that are collectively referred to as static electricity. The charge can be
built by rubbing certain objects together, such as silk and glass or rubber
and fur; the friction between these objects causes Electrons
to transfer from one to another with the result that the object losing electrons acquires
a positive charge and the object gaining electrons acquires a negative charge.
Electrodynamics is the study of charges in motion. A flow of electric charge constitutes
an electric current. In order for a current to exist in a conductor, there must be an
Electromotive Force (emf), or potential difference, between the conductor's ends. An
electric Cell, a Photovoltaic Cell,
and a Generator are all sources of emf. An emf source with
an external conductor connected from one of the source's two terminals to the other
constitutes an Electric Circuit. Direct current (DC) is a
flow of current in one direction at a constant rate. Alternating current (AC) is a current
flow that increases in magnitude from zero to a maximum, decreases back to zero, increases
to a maximum in the opposite direction, decreases to zero, and then repeats this process
periodically. The number of repetitions of the cycle occurring each second
is defined as the frequency, which is expressed in Hertz (Hz).
The frequency of ordinary household current in the U.S. is 60 cycles per sec (60 Hz), and
electric devices must be designed to operate at this frequency. In a solid, the current
consists not of a few electrons moving rapidly but of many electrons moving slowly;
although this drift of electrons is slow, the impulse that causes it moves through the
circuit, when the circuit is completed, at nearly the speed of light. The movement of
electrons in a current is not steady; each electron moves in a series of stops and starts.
In a direct current, the electrons are spread evenly through the conductor; in an
alternating current, the electrons tend to congregate along the conductor surface. In
liquids, gases, and semiconductors, current carriers may be positively or negatively
charged.
- Electrode
- An electrode is a terminal, usually in the form of a wire,
rod, or plate, through which electric current passes between metallic and nonmetallic
parts of an Electric Circuit. The electrode through which
current passes from the metallic to the nonmetallic conductor is called the anode; that
through which current passes from the nonmetallic to the metallic conductor is called the
cathode. An electrode may be made of a metal, e.g., copper, lead, platinum, silver, or
zinc, or of a nonmetal, commonly carbon.
- Electrolysis
- The passage of an electric current through a conducting
solution or molten salt (either is a type of Electrolyte
that is decomposed in the process. When a cathode, or negative electrode, and an anode, or
positive electrode, are dipped into a solution, and a direct-current source is connected
to the electrodes, the positive ions migrate to the negative electrode and the negative
ions migrate to the positive electrode. At the negative electrode each positive ion gains
an electron and becomes neutral; at the positive electrode each negative ion gives up an
electron and becomes neutral. The migration of ions through the electrolyte constitutes
the electric current flowing from one electrode to the other. Electrolysis is used in the
commercial preparation of various substances, e.g., chlorine by the electrolysis of a
solution of common salt, and hydrogen by the electrolysis of water. The electrolysis of
metal salts is used for plating.
- Electrolyte
- An electrical conductor in which current is carried by Ions rather than free electrons (as in a metal). Electrolytes include
water solutions of acids, bases or salts; certain pure liquids; and molten salts. Electrolysis.
- Electromagnet
- A device in which an electric current, passing through a wire
coil wrapped around a soft iron core, produces a magnetic field. The magnetic-field
strength produced depends on the number of turns of the coil of wire, the size of the
current, and the magnetic permeability of the core. Electromagnets lose their magnetism
when the current is discontinued.Superconductivity.
-
- Electromagnetic Radiation
|
Electromagnetic radiation is energy
radiated in the form of a Wave caused by an electric field interacting with a
magnetic field. Electromagnetic radiation is the result of the acceleration of a charged
particle. It does not require a material medium, and can travel through a vacuum. The
theory of electromagnetic radiation was developed by James Clerk Maxwell and published in
1865, although his ideas were not accepted until Heinrich Hertz proved the existence of
radio waves in 1887. In order of decreasing wavelength and increasing frequency, the
various types of electromagnetic radiation are Radio waves,
Microwaves, Infrared Radiation,
visible Light, Ultraviolet Radiation,
X-Rays, and Gamma Radiation. The
possible sources of electromagnetic radiation are directly related to wavelength; long
radio waves are produced by large antennas such as those used by broadcasting stations;
much shorter visible light waves are produced by the motions of charges within atoms; the
shortest waves, those of gamma radiation, result from changes within the nucleus of the
atom. The individual quantum of electromagnetic radiation is known as the Photon. |
- Electromotive Force
- Electromotive force (emf) is the difference in electric Potential, or voltage, between the terminals of a source of
electricity. It is usually measured in Volts.
- Electron
- An electron is an Elementary Particle
carrying a unit charge of negative electricity. An Atom
consists of a small, dense, positively charged nucleus surrounded by electrons that whirl
about it in orbits, forming a cloud of charge. Ordinarily there are just enough negative
electrons to balance the positive charge of the nucleus, and the atom is neutral. If
electrons are added or removed, a net charge results, and the atom is said to be ionized (
Ion). Atomic electrons are responsible for the chemical properties
of matter ( Valence). The electron was discovered in 1897 by
Joseph John Thomson, who showed that cathode rays are composed of electrons. The electron
is the lightest known particle having a non-zero rest mass. The positron, the electron's
antiparticle ( Antimatter), was discovered in 1932.
- Electron Tube
- Electron tube, device consisting of a sealed enclosure in
which electrons flow between Electrodes separated either by
vacuum (in a vacuum tube) or by an ionized gas at low pressure (in a gas tube). The two
principal electrodes of an electron tube are called the anode and cathode. The simplest
vacuum tube, the Diode, contains only these two electrodes. When the cathode is
heated, it emits a cloud of electrons, which are attracted to the positive polarity of the
anode and constitute the current through the tube. Because the anode is not capable of
emitting electrons, no current can flow in the reverse direction, and the diode acts as a Rectifier. In the vacuum triode, small signals applied to a
third electrode, called a grid, placed between the cathode and anode cause large
fluctuations in the current between the cathode and anode. A triode can thus act as a
signal Amplifier. Although formerly the key elements of Electric
Circuits, electron tubes have been almost entirely displaced by Semiconductor devices. Also Cathode-Ray
Tube.
- Element
- In chemistry, substance composed of Atoms
all having the same number of Protons in their nuclei. This
number, called the Atomic Number, defines the element and
establishes its place in the Periodic Table. Each
element is assigned a symbol of one or two letters (see table). The total number of
protons and Neutrons in the nucleus of an atom is called the
Mass Number. Although all atoms of an element have the same
number of protons in their nuclei, they may not all have the same number of neutrons.
Atoms of an element with the same mass number make up an Isotopeof
the element. All elements have isotopes; over 1,000 isotopes of the elements are known. As
of 1989, 108 elements were known. Only 92 elements occur naturally on earth; the others
are produced artificially ( Synthetic Elements, Transuranium Elements). The chemical properties of an element
are due to the distribution of electrons around the nucleus, particularly the outer, or Valence, electrons (the ones involved in chemical reactions).
Chemical reaction does not affect the nucleus and thus does not change the atomic number.
For this reason an element is often defined as a substance that cannot be decomposed into
simpler substances by chemical means. Also Atomic Weight; Compound; Molecule.
-
| Element |
Symbol |
Atomic Number |
Atomic Weight1 |
Melting Point (Degrees Centigrade) |
Boiling Point (Degrees Centigrade) |
| actimium |
Ac |
89 |
227.0278 |
1050 |
3200.±300 |
| aluminum |
Al |
13 |
26.98154 |
660.37 |
2467 |
| americium |
Am |
95 |
-243 |
994.±4 |
2607 |
| antimony |
Sb |
51 |
121.75 |
630.74 |
1950 |
| argon |
Ar |
18 |
39.948 |
-189.2 |
-185.7 |
| arsenic |
As |
33 |
74.9216 |
817. (28 atmospheres) |
613. (sublimates) |
| astatine |
At |
85 |
-210 |
302 (est.) |
337. (est.) |
| barium |
Ba |
56 |
137.33 |
725 |
1640 |
| berkelium |
Bk |
97 |
-247 |
-- |
-- |
| beryllium |
Be |
4 |
9.01218 |
1278.±5 |
2970 |
| bismuth |
Bi |
83 |
208.9804 |
271.3 |
1560.±5 |
| boron |
B |
5 |
10.81 |
2079 |
2550. (sublimates) |
| bromine |
Br |
35 |
79.904 |
-7.2 |
58.78 |
| cadmium |
Cd |
48 |
112.41 |
320.9 |
765 |
| calcium |
Ca |
20 |
40.08 |
839.±2 |
1484 |
| californium |
Cf |
98 |
-251 |
-- |
-- |
| carbon |
C |
6 |
12.011 |
~3550. |
4827 |
| cerium |
Ce |
58 |
140.12 |
799 |
3426 |
| cesium |
Cs |
55 |
132.9054 |
28.4 |
669.3 |
| chlorine |
Cl |
17 |
35.453 |
-100.98 |
-34.6 |
| chromium |
Cr |
24 |
51.996 |
1857.±20 |
2672 |
| cobalt |
Co |
27 |
58.9332 |
1495 |
2870 |
| copper |
Cu |
29 |
63.546 |
1083.4±0.2 |
2567 |
| curium |
Cm |
96 |
-247 |
1340.±40 |
-- |
| dysprosium |
Dy |
66 |
162.5 |
1412 |
2562 |
| einsteinium |
Es |
99 |
-252 |
-- |
-- |
| erbium |
Er |
68 |
167.26 |
1522 |
2863 |
| europium |
Eu |
63 |
151.96 |
822 |
1597 |
| fermium |
Fm |
100 |
-257 |
-- |
-- |
| fluorine |
F |
9 |
18.998403 |
-219.62 |
-188.14 |
| francium |
Fr |
87 |
-223 |
(27) (est.) |
(677) (est.) |
| gadolinium |
Gd |
64 |
157.25 |
1313.±1 |
3266 |
| gallium |
Ga |
31 |
69.72 |
29.78 |
2403 |
| germanium |
Ge |
32 |
72.59 |
937.4 |
2830 |
| gold |
Au |
79 |
196.9665 |
1064.43 |
3080 |
| hafnium |
Hf |
72 |
178.49 |
2227.±20 |
4602 |
| helium |
He |
2 |
4.0026 |
<-272.2 |
-268.934 |
| holmium |
Ho |
67 |
164.9304 |
1474 |
2695 |
| hydrogen |
H |
1 |
1.00794 |
-259.14 |
-252.87 |
| indium |
In |
49 |
114.82 |
156.61 |
2080 |
| iodine |
I |
53 |
126.9045 |
113.5 |
184.35 |
| iridium |
Ir |
77 |
192.22 |
2410 |
4130 |
| iron |
Fe |
26 |
55.847 |
1535 |
2750 |
| krypton |
Kr |
36 |
83.8 |
-156.6 |
-152.30±0.10 |
| lanthanum |
La |
57 |
138.9055 |
921 |
3457 |
| Iawrencium |
Lw |
103 |
-260 |
-- |
-- |
| lead |
Pb |
82 |
207.2 |
327.502 |
1740 |
| lithium |
Li |
3 |
6.941 |
180.54 |
1342 |
| Iutetium |
Lu |
71 |
174.967 |
1663 |
3395 |
| magnesium |
Mg |
12 |
24.305 |
648.8±0.5 |
1090 |
| manganese |
Mn |
25 |
54.938 |
1244.±3 |
1962 |
| mendelevium |
Md |
101 |
-258 |
-- |
-- |
| mercury |
Hg |
80 |
200.59 |
-38.842 |
356.58 |
| molybdenum |
Mo |
42 |
95.94 |
2617 |
4612 |
| neodymium |
Nd |
60 |
144.24 |
1021 |
3068 |
| neon |
Ne |
10 |
20.179 |
-248.67 |
-246.048 |
| neptunium |
Np |
93 |
237.0482 |
640.+1 |
3902. (est.) |
| nickel |
Ni |
28 |
58.69 |
1453 |
2732 |
| niobium |
Nb |
41 |
92.9064 |
2468.+10 |
4742 |
| nitrogen |
N |
7 |
14.0067 |
-209.86 |
-195.8 |
| nobelium |
No |
102 |
-259 |
-- |
-- |
| osmium |
Os |
76 |
190.2 |
3045.+30 |
5027.+100 |
| oxygen |
O |
8 |
15.9994 |
-218.4 |
-182.962 |
| palladium |
Pd |
46 |
106.42 |
1554 |
2970 |
| phosphorus |
P |
15 |
30.97376 |
44.1 (white) |
280. (white) |
| platinum |
Pt |
78 |
195.08 |
1772 |
3827.±100 |
| plutonium |
Pu |
94 |
-244 |
641 |
3232 |
| polonium |
Po |
84 |
-209 |
254 |
962 |
| potassium |
K |
19 |
39.0983 |
63.25 |
760 |
| praseodymium |
Pr |
59 |
140.9077 |
931 |
3512 |
| promethium |
Pm |
61 |
-145 |
~1168.±6 |
2460 |
| protactinium |
Pa |
91 |
231.0359 |
<1600. |
-- |
| radium |
Ra |
88 |
226.0254 |
700 |
1140 |
| radon |
Rn |
86 |
-222 |
-71 |
-61.8 |
| rhenium |
Re |
75 |
186.207 |
3180 |
5627. (est.) |
| rhodium |
Rh |
45 |
102.9055 |
1966.±3 |
3727.±100 |
| rubidium |
Rb |
37 |
85.4678 |
38.89 |
686 |
| ruthenium |
Ru |
44 |
101.07 |
2310 |
3900 |
| samarium |
Sm |
62 |
150.36 |
1072.±5 |
1791 |
| scandium |
Sc |
21 |
44.9559 |
1541 |
2831 |
| selenium |
Se |
34 |
78.96 |
217 |
684.9±1.0 |
| silicon |
Si |
14 |
28.0855 |
1410 |
2355 |
| silver |
Ag |
47 |
107.8682 |
961.93 |
2212 |
| sodium |
Na |
11 |
22.98977 |
97.81±0.03 |
882.9 |
| strontium |
Sr |
38 |
87.62 |
269 |
1384 |
| sulfur |
S |
16 |
32.06 |
112.8 |
444.674 |
| tantalum |
Ta |
73 |
180.9479 |
2996 |
5425.±100 |
| technetium |
Tc |
43 |
-98 |
2172 |
4877 |
| tellurium |
Te |
52 |
127.6 |
449.5±0.3 |
989.8±3.8 |
| terbium |
Tb |
65 |
158.9254 |
1356 |
3123 |
| thallium |
Tl |
81 |
204.383 |
303.5 |
1457.±10 |
| thorium |
Th |
90 |
232.0381 |
1750 |
~4790. |
| thulium |
Tm |
69 |
168.9342 |
1545.±15 |
1947 |
| tin |
Sn |
50 |
118.69 |
231.9681 |
2270 |
| titanium |
Ti |
22 |
47.88 |
1660.±10 |
3287 |
| tungsten |
W |
74 |
183.85 |
3410.±20 |
5660 |
| unnilennium |
Une |
109 |
-266 |
-- |
-- |
| unnilhexium |
Unh |
106 |
-263 |
-- |
-- |
| unnilpentium2 |
Unp |
105 |
-262 |
-- |
-- |
| unnilquadium3 |
Unq |
104 |
-261 |
-- |
-- |
| unnilseptium |
Uns |
107 |
-262 |
-- |
-- |
| uranium |
U |
92 |
238.0289 |
1132.3±0.8 |
3818 |
| vanadium |
V |
23 |
50.9415 |
1890.±10 |
3380 |
| xenon |
Xe |
54 |
131.29 |
-111.9 |
-107.1±3 |
| ytterbium |
Yb |
70 |
173.04 |
819 |
1194 |
| yttrium |
Y |
39 |
88.9059 |
1522.±8 |
3338 |
| zinc |
Zn |
30 |
65.38 |
419.58 |
907 |
| zirconium |
Zr |
40 |
91.22 |
1852.±2 |
4377 |
| 1 Parentheses indicate most stable isotope for atomic
weight. |
|
| 2 Other proposed names are nielsbohrium (USSR) and hahnium
(U 5.). |
|
| 3 Other proposed names are kurchatovium (USSR) and
rutherfordium (U.S.). |
|
- Elementary Particles
- Elementary particles are tiny bits of matter assumed to be the
most basic constituents of the universe. Certain elementary particles combine to form an Atom, which is the basic unit of any chemical Element
and from which all forms of matter are built. The first elementary particle to be
discovered was the Electron, identified in 1897 by Joseph
John Thomson. The nucleus of ordinary hydrogen was subsequently recognized as a single
particle and was named the Proton. The third basic particle
in an atom, the Neutron, was discovered in 1932. Although
models of the atom consisting of just these three particles are sufficient to account for
all forms of chemical behavior of matter, Quantum Theory
predicted the existence of additional elementary particles. A search for the positron, or
antiparticle ( Antimatter) of the electron, led to its
detection in 1932, but a search for a particle predicted by Yukawa Hideki in 1935 led to
the unexpected discovery of the mu meson, or muon, the following year. Yukawa's particle
was finally discovered in 1947 and named the pi meson, or pion. Both the muon and the pion
were first observed in Cosmic Rays. As the list of particles
and antiparticles grew, through further study of cosmic rays and the study of the results
of particle collisions produced by Particle Accelerators,
four basic categories of particles were distinguished, according to their behavior with
regard to the four fundamental forces of nature: gravitational, electromagnetic, strong
nuclear, and weak nuclear. A given particle experiences certain of these forces but may be
immune to others. The gravitational force is experienced by all particles. The
electromagnetic force is experienced only by charged particles, although it is transmitted
by the Photon, which has no charge. The weak and strong
nuclear forces exist only at the atomic level. Of the four classes of particles, the
smallest is that of the massless bosons, which include the photon, eight types of gluons,
and the hypothetical graviton. The lepton class includes twelve particles: the electron,
the positron, the positive and negative muons, the tauon and its antiparticle, and the
neutrino or antineutrino associated with each of these particles. The bosons and the
leptons are not strongly interacting. Members of the meson class are more massive than the
leptons. The mesons are the “glue” that holds nuclei together. By far the
largest class of particles is the baryon class, the lightest members of which are the
proton and neutron; the heavier members are the hyperons. Baryons and mesons, both
strongly interacting, are sometimes considered together as hadrons. A theory independently
proposed in 1964 by Murray Gell-Mann and George Zweig explains the properties of all known
hadrons according to the assumption that hadrons are built up of other, still more
fundamental particles called Quarks.
- Ellipse
- A plane curve constituting the locus of all points the sum of
whose distances from two fixed points called "foci" is constant; an elongated
circle. Conic Section. (The orbits of planets, satellites, planetoids and comets
are ellipses; center of attraction is at one focus.)
- Emulsion
- A blasting agent in which the AN is encapsulated by the fuel
in an emulsion of water in oil.
- An explosive material containing substantial amounts of
oxidizers dissolved in water droplets, surrounded by an immiscible fuel.
- End Burning
- A term used to describe a solid propellant grain which is
inhibited so that it burns from one end only so that burning progresses in the direction
of the longitudinal axis.
- Endothermal
- A reaction that occurs with the absorption of heat.
- Energy
 |
A measure of the potential for the
explosive to do work. More specifically, energy in physics is the ability or capacity to
do Work. Forms of energy include Heat,
chemical energy, and, according to the theory of Relativity,
Mass ( Nuclear Energy); other
forms of energy are associated with the transmission of Light,
Sound, and Electricity. Energy
and work are measured in the same units: Joules, ergs,
electron-volts, calories, foot-pounds, or some other, depending on the system of
measurement being used. When a force acts on a body, the work performed (and the energy
expended) is the product of the force and the distance over which it is exerted. Potential
energy is the capacity for doing work that a body possesses because of its position or
condition. For example, a weight lifted to a certain height has potential energy because
of its position in earth's gravitational field. Kinetic energy, the energy a body
possesses because it is in motion, is equal to 1/2mv2, where m is its mass and
v is its velocity. The average kinetic energy of the atoms or molecules of a body is
measured by the Temperature of the body. Energy (or its
equivalent in mass) can be neither created nor destroyed ( Conservation
Laws), but it can be changed from one form into another. |
- Energy, Sources of
- In contemporary usage, energy is whatever can be efficiently
converted into heat or motion to provide power to run machines and vehicles and to supply
heat and light. Energy sources are of two basic types, renewable and nonrenewable. Most of
the industrial world is presently powered by nonrenewable fossil fuels - coal, Petroleum, and Natural gas - that,
once used, cannot be replaced. Fission Nuclear reactors are
fueled by uranium or plutonium, themselves finite energy sources. Spent uranium,
however, can be converted to fissile plutonium in a breeder reactor, a process that makes
nuclear energy almost infinitely renewable. Nuclear technology, however, has not yet
developed either failproof reactors or a safe method for disposing of nuclear wastes. The
development of nuclear fusion (whose end products are harmless) has so far been hindered
by the difficulties of containing the fuels (plentiful light elements such as hydrogen) at
the extremely high temperatures necessary to initiate and sustain fusion. Renewable energy
sources include the energy from water and wind (i.e. turbines; water wheels and
windmills); geothermal energy, the earth's internal heat that is released naturally in
geysers and volcanoes; tidal energy, the power released by the ebb and flow of the ocean's
tides; biomass, the use of certain crops (including wood) or crop wastes either directly
as fuel or as a fermentable source of fuels such as alcohol or methane; and Solar
energy, which can be stored and used directly as heat, or transformed into electricity
through the use of Photovoltaic cells. All these renewable
energy sources are presently being tapped in some form, but none can replace fossil fuels
without huge advances in the technologies needed to exploit them.
- English Units Of Measurement
- English units of measurement is the principal system of a few
nations, the only major industrial one being the United States. The English system
actually consists of two related systems -- the U.S. Customary System, used in the United
States and dependencies, and the British Imperial. Great Britain, the originator of the
latter system, is now gradually converting to the Metric System.
The names of the units and the relationships between them are generally the same in both
systems, but the sizes of the units differ, sometimes considerably. The basic unit of
length is the yard (yd); the basic unit of mass (weight) is the pound (lb). Within the
English units of measurement there are three different systems of weights (avoirdupois,
troy, and apothecaries'), of which the most widely used is the avoirdupois. The troy
system (named for Troyes, France, where it is said to have originated) is used only for
precious metals. Apothecaries' weights are based on troy weights; in addition to the
pound, ounce, and grain - which are equal to the troy units of the same name - other units
are the dram and the scruple. For liquid measure, or liquid capacity, the basic unit is
the gallon. The U.S. gallon, or wine gallon, is 231 cubic inches (cu in.); the British
imperial gallon is the volume of 10 lb of pure water at 62°F and is equal to 277.42 cu
in. The British units of liquid capacity are thus about 20% larger than the corresponding
American units. The U.S. bushel, or Winchester bushel, is 2,150.42 cu in. and is about 3%
smaller than the British Imperial bushel of 2,219.36 cu in.; a similar difference exists
between U.S. and British subdivisions. The barrel is a unit for measuring the capacity of
larger quantities and has various legal definitions depending on the substance being
measured, the most common value being 105 dry quarts. Since the Mendenhall Order of 1893,
the U.S. yard and pound and all units derived from them have been defined in terms of the
metric units of length and mass, the meter (m) and the kilogram (kg); since 1959 these
values are 1 yd = 0.9144 m and 1 lb = 0.45359237 kg. In the United States, the older
definition of the yard as 3,600/3,937 m is still used for surveying, the corresponding
foot (1,200/3,937 m) being known as the survey foot.
- Enthalpy
- In thermodynamics, a term
meaning total heat energy.
- Envelope
- Used to signify a container, also the overall dimensions of an
item.
- Environmental Testing
- Tests referring to exposure of items to climatic, mechanical
and other external stresses.
- Enzyme
- An enzyme is a protein functioning as a biological Catalyst. Enzymes accelerate (often by several orders of
magnitude) chemical reactions in the cell that would proceed imperceptibly or not at all
in their absence. The enzyme is not permanently modified by its participation. Most
enzymes demonstrate great specificity, reacting with only one or a small group of closely
related chemical compounds; thus, sometimes several enzymes are required for efficient
catalytic function. Some enzymes depend on the presence of Coenzymes
for their function. For the enzyme to continue to be effective, its three-dimensional
molecular structure must be maintained. X-ray crystallography is used to analyze the
structure of enzymes. Over 1,000 different enzymes have been identified, and the exact
sequence of Amino Acids (subunits of a protein)
has been determined for many proteins since 1967, when the first such determination was
made. It is believed that enzymes function by attaching the substrate molecule to a
specific molecular site, so that the electrostatic forces of nearby atoms sharply reduce
the energy needed to cleave and re-form the appropriate chemical bonds.
- Equal Section Charge
- Propelling charge made up of a number of charges equal in
size. The number of sections used determines the muzzle velocity and range of the
projectile.
- Equation Of State
- An equation relating the volume, temperature and pressure of a
system.
- Erosion
- 1) In a solid rocket, the wearing away of the propellant due
to heat, radiation and gas velocity.
- 2) Wearing away of a bore due to combined effect of gas
washing, scouring and mechanical abrasion. ( Corrosion.)
- Escape Velocity
- The radial speed which a particle or larger body must attain
in order to escape from the gravitational field of a planet or star.
- Ethanol
- Ethanol, or ethyl alcohol (CH3CH2OH), a
colorless liquid with characteristic odor and taste, commonly called grain alcohol or,
simply, Alcohol. Ordinary ethanol is about 95% pure, the
remaining 5% being water, which can only be removed with difficulty to give pure or
absolute ethanol. Ethanol is the alcohol in beer, wine, and liquor, and can be made by the
fermentation of sugar or starch. Denatured alcohol, for industrial use, is ethanol with
toxic additives. Ethanol is used as a solvent in the manufacture of varnishes and
perfumes; as a preservative; in medicines; as a disinfectant; and as a fuel. Ethanol is a
soporific; if its presence in the blood exceeds about 5%, death usually occurs. Behavioral
changes, impairment of vision, or unconsciousness occur at lower concentrations.
- Ether
- Ethere or aether, in physics, a hypothetical medium for
transmitting Electromagnetic radiation, filling all
unoccupied space. The theory of Relativity eliminated the
need for such a medium, and the term is used only in a historical context.
- Exosphere
- The outermost, or topmost, position of the atmosphere.
- Exothermal
- A process characterized by the evolution of heat.
- Expansion Ratio
- In rocketry, the ratio of nozzle exit area to the nozzle
throat area.
- Expelling Charge
- Quantity of propellant used in special purpose shell to eject
the contents of the shell.
- Explode
- To be changed in chemical or physical state usually from a
solid or liquid to a gas (as by chemical decomposition or sudden vaporization) so as to
suddenly transform considerable energy into the kinetic form.
- To be changed in chemical or physical state, usually from a
solid or liquid gas (as by chemical decomposition or sudden vaporization) so as to
suddenly transform considerable energy into the kinetic form Explosion.
- Exploder
- An alternative term for a fuze, usually used in connection
with torpedoes.
- Exploding Bridge Wire
- EBW.
- Explosion
- A chemical reaction or change of state with the generation and
extremely rapid expansion of gases, usually associated with the liberation of heat. An
explosion produces a shock wave in the surrounding medium.
- A rapid chemical reaction with the generation of high
temperature and usually a large quantity of gas.
- Explosive
- Substance which, when subjected to heat, impact, friction or
other suitable initial impulse, undergoes an explosion that is a very rapid chemical
transformation, forming other more stable products entirely or largely gaseous, whose
combined volume is much greater than that of the original substance. Explosives are
classified as high-explosive or low-explosive, according to the rate of transformation.
- Any chemical compound, mixture, or device, the primary or
common purpose of which is to function by explosion.
- Explosive Actuated Device
- Any tool or special mechanized device that is actuated by
explosives. The term does not include propellant-actuated devices. ( Propellant-Actuated
Power Device.)
- Examples of explosive-actuated devices are jet tappers and jet
perforators.
- Explosive Bolt
- A bolt that is intended to be fractured at a predetermined
point by a contained or inserted explosive charge for the purpose of releasing a load. Explosive
Charge
- Predetermined quantity of explosive required to produce a
specific effect. Bursting Charge; Expelling Charge; Propelling Charge.
- Explosive Charge
- The quantity of explosive material used in an explosive
device, or in industrial applications refers to explosive material in a blasthole, coyote
tunnel, or other form of placement.
- Explosive D
- Ammonium picrate, a high explosive charge that is not easily
set off in transportation or in handling, etc. Sometimes it is used as a bursting charge
in armor-piercing projectiles.
- Explosive Entry
- The utilization of explosive devices to facilitate access into
a target area through a conventional or non-conventional breach point.
- Explosive Logic
- Material Being Added
- Explosive Nut
- A nut that is intended to be fractured by a contained or
inserted explosive charge for the purpose of releasing a load.
- Explosive Oils
- Liquid sensitizers for explosives such as nitroglycerin,
ethylene glycol dinitrate, and metriol trinitrate.
- Explosive Strength
- The amount of energy released by an explosive upon detonation
that is an indication of the capacity of the explosive to do work.
- Explosive Switch
- A self-contained electrically initiated small unit which
causes one or more electric circuits to be opened and / or closed by "explosive"
(actually propulsive) action.
- Explosive Train
- An arrangement of a series of combustible and explosive
elements consisting of a primer, a detonator, a delay, a relay, a lead and booster charge,
one or more of which may be either combined with another element or omitted. The function
of the explosive train is to accomplish the controlled augmentation of a relatively small
impulse into one of sufficient energy to cause the main charge of the munition to
function.
- A train of combustible and explosive elements arranged in
order of decreasing sensitivity. The explosive train accomplishes the controlled
augmentation of a small impulse into one of suitable energy to actuate the main charge. A
fuze explosive train may consist of a primer, a detonator, a delay, a relay, a lead and
booster charge, one or more of which may be either omitted or combined. If the bursting
charge is added to the foregoing train it becomes a bursting charge explosive train. A
propelling charge explosive train might consist of a primer, igniter or igniting charge,
usually black powder, and finally, any of the various types of propellants. ( Igniter Train.)
- Explosive Wave
- A wave of chemical action which passes through an explosive
substance when it explodes; also, more accurately, detonation zone.
- Exterior Ballistics
- The branch of ballistics which deals with the motion of the
projectile after it leaves the gun.
- Extraneous Electricity
- Electrical energy, other than actual firing current or the
test current from a blasting galvanometer, that is present
at a blast site and that could enter an electric blasting circuit. It includes stray
current, static electricity, RF (electromagnetic) waves, and time-varying electric and
magnetic fields.
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