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P

Paraffin
Paraffin, white, semitranslucent, odorless, tasteless, water insoluble, waxy solid. Though relatively inert, it burns readily in air. A mixture of Hydrocarbons obtained from Petroleum during refining, paraffin is used in candles and for coating paper.
Parallax
Parallax Any alteration in the relative apparent positions of objects produced by a shift in the position of the observer. Stellar parallax is the apparent displacement of a nearby star against the background of more distant stars resulting from the motion of the earth in its orbit around the sun; formally, the parallax of a star is the angle at the star that is subtended by the mean distance 1 Astronomical Unit between the earth and the sun. A star's distance (d) in parsecs is thus the reciprocal of its parallax (p) in seconds of arc (or d = 1/p). Friedrich Bessel measured (1838) the first stellar parallax (0.3 seconds of arc for the star 61 Cygni). Geocentric parallax, used to determine the distances of solar system objects, is measured similarly; the diameter of the earth, rather than that of its orbit, however, is used as the baseline.
Parallel Blasting Circuit
An electric blasting circuit in which the legwires of each detonator are connected across the firing line directly or through buswires.
Parallel-Series Circuit
Series in Parallel Blasting Circuit.
Parasheet
Parachute-like device made from a single flat piece of material, or as few pieces as its size will permit; avoids cost of complex gore construction of parachute.
Parsec
Parsec, a unit of length equal to the distance (206,265 Astronomical Units; 3.26 Light-Years; 1.917 × 1013 mi; or 3.086 × 1013 km) at which a hypothetical star's Parallax would be one second of arc. The distance in parsecs of an object from the earth is thus the reciprocal of the parallax in seconds of the object.
Particle Accelerator
A device used to produce beams of energetic charged particles and to direct them against various targets for studies of the structure of the atomic nucleus Atom and of the forces holding it together. Accelerators also have applications in medicine and industry, most notably in the production of radioisotopes. The first stage of any accelerator is an Ion source to produce the charged particles from a neutral gas. The charged particles are accelerated by electric fields. In linear accelerators, which are the most powerful and efficient electron accelerators, the particle path is a straight line. The early linear accelerators used large static electric charges, which produced an electric field along the length of an evacuated tube to accelerate the particles. Present linear accelerators use electromagnetic waves to accomplish the acceleration. To reach high energies without prohibitively long paths, E.O. Lawrence designed the cyclotron, in which a cylindrical magnet bends the particle beam into a circular path in a hollow circular metal box that is split in half to form two D-shaped sections. A radio-frequency electric field is applied across the gap, accelerating the particle each time it crosses the gap. In the synchrocyclotron, used to accelerate protons, the frequency of the accelerating electric field steadily decreases to match the decreasing angular velocity of the proton caused by the increase of its mass at relativistic velocities, i.e., those close to the speed of light. In the synchrotron, a ring of magnets surrounding a doughnut-shaped vacuum tank produces a magnetic field that rises in step with the proton velocities, thus keeping the radius of their paths constant; this design eliminates the need for a center section of the magnet, allowing construction of rings with diameters measured in miles.
Particle Board
A composition board made of small pieces of wood bonded together.
Particle Velocity
A measure of the intensity of material vibration, specifically the time rate of change of the amplitude of material vibration.
PBX
Abbreviation for plastic bonded explosives. Of particular importance for tactical operations are the “sheet explosives” which are made with PETN or RDX, depending on the product. Sheet Explosive.
Peat
Peat, soil material consisting of partially decomposed organic matter, formed by the slow decay of aquatic and semiaquatic plants in Swamps and bogs. Principal types include moss peat, derived chiefly from Sphagnum and used as mulch and stable litter, and fuel peat, used where wood and coal are scarce. Peat is the first stage of transition from compressed plant growth to the formation of Coal.
Peak Pressure
Instantaneous maximum pressure developed in the gun chamber by burning propellant; pressure immediately preceding an expanding shock wave.
Pellet
A consolidated charge.
Pelleting
Process of consolidating charges.
Pentolite
An explosive composition of PETN and TNT, but usually a 50/50 composition. Can be melt pour.
Percussion
A method of initiating an explosive item by a sudden sharp blow.
Percussion Composition
High-explosive powder that is ignited in some types of firearms by the blow of the firing pin against the primer cap.
Percussion Fuze
Impact Fuze.
Percussion Primer
Cap or cylinder containing a small charge of high explosive that may be set off by a blow. A percussion primer is used in all fixed and semi-fixed ammunition and in certain types of separate-loading ammunition to ignite the main propelling charge.
Perforation
Passage of a missile completely through an object.
Periodic Table
Periodic table, chart that reflects the periodic recurrence of chemical and physical properties of the Elements when the elements are arranged in order of increasing Atomic Number. The periodic table was devised by Dmitri Mendeleev and revised by Henry Moseley It is divided into vertical columns, or groups, numbered from I to VIII, with a final column numbered 0. Each group is divided into two categories, or families, one called the a series (the representative, or main group, elements) the other the b series (the Transition Elements, or subgroup elements). All the elements in a group have the same number of Valence electrons and have similar chemical properties. The horizontal rows of the table are called periods. The elements of a particular period have the same number of electron shells; the number of electrons in these shells, which equals the element's atomic number, increases from left to right within each period. In each period the lighter Metals appear on the left, the heavier metals in the center, and the nonmetals on the right. Elements on the borderline between metals and nonmetals are called metalloids. Elements in group Ia are called the Alkali Metals; in group IIa, the Alkaline-Earth Metals; in group VIIa, the Halogens; and in group 0, the Inert Gases.
Peripheral Test
A brief test program conducted on an item or system to determine if it will meet only the most rigorous specified requirements.
Permissible Diameter (Smallest)
The smallest diameter of a permissible explosive, as approved by the Mine Safety and Health Administration (MSHA).
Permissible Individual Maximum Pressure
For any type gun, that value which should not be exceeded by the maximum pressure developed by an individual round under any service condition.
PE
Abbreviation of “plastic explosives”. They consist of high brisance explosives such as RDX or PETN combined with plasticizers. PBX and Plastic Explosives.
Petard
Device intended to breach a door or gate.
PETN
1) An explosive compound, pentaerythritol tetranitrate represented by the empirical formula C5H8N4O12 , it is a colorless crystal, with a molecular weight 316.1 and density of 1.76 g/cm3. Oxygen balance: -10.1%, nitrogen content: 17.72%, volume of detonation gases 823 l/kg. Detonation velocity, confined: 8400 m/s = 27,600 ft/s at r = 1.70 g/cm3. Critical diameter of steel sleeve test: 6mm. Deflagration point: 202 °C = 396 F, impact sensitivity 3 N m. PETN is very stable, insoluble in water, sparingly soluble in alcohol, ether and benzene, and soluble in acetone and methyl acetate.
2) A high explosive of exceptional brisance, pentaerythrite tetranitrate. Used in detonating cord, boosters, detonators, blasting caps and as a constituent of Dentolite. in which it is mixed with TNT
Petroleum
Petroleum or crude oil, oily, flammable liquid that occurs naturally in deposits, usually beneath the surface of the earth. The exact composition varies according to locality, but it is chiefly a mixture of Hydrocarbons. Petroleum is a fossil fuel thought to have been formed over millions of years from incompletely decayed plant and animal remains buried under thick layers of rock. Drilling for oil is a complex, often risky process. Scientific methods are used to locate promising sites for wells, some of which must be dug several miles deep to reach the deposit. Many wells are now drilled offshore from platforms standing on the ocean bed. Usually the crude oil in a new well comes to the surface under its own pressure. Later it has to be pumped or forced up with injected water, gas, or air. Pipelines or tankers transport it to refineries, where it is separated into fractions, i.e., the portions of the crude oil that vaporize between certain defined limits of temperature. Fractions are obtained by a refining process called fractional Distillation in which crude oil is heated and sent into a tower. The vapors of the different fractions condense on collectors at different heights in the tower. The separated fractions are then drawn from the collectors and further processed into various petroleum products. Generally the fractions are vaporized in the following order: dissolved Natural Gas, Gasoline, naphtha, Kerosene, diesel fuel, heating oils, and finally tars. Lighter fractions, especially gasoline, are in greatest demand and their yield can be increased by breaking down heavier hydrocarbons in a process called cracking. The leading producers of petroleum in 1980 were the USSR, Saudi Arabia, the U.S., Iraq, Venezuela, China, Nigeria, Mexico, Libya, and the United Arab Emirates. The largest reserves are in the Middle East. Modern industrial civilization depends heavily on petroleum for motive power, fuel, lubrication, and a variety of synthetic products, e.g., dyes, drugs, and Plastics. The widespread burning of petroleum as fuel has resulted in serious problems of air pollution, and oil spilled from tankers and offshore wells has damaged oceans and coastlines. Unless the need for oil is reduced, conservationists may be unable to prevent the development of oil deposits whose exploitation poses threats to the environment. See also Energy, Sources Of.
pH
pH, range of numbers expressing the relative acidity or alkalinity of a solution. The pH value is the negative common Logarithm of the hydrogen-ion Concentrationin a solution expressed in Moles per liter of solution. A neutral solution is one that is neither acidic nor alkaline such as pure water has a concentration of 10-7 moles per liter; its pH is thus 7. Acidic solutions have pH values ranging with decreasing acidity from 0 to nearly 7; alkaline or basic solutions have a pH ranging with increasing alkalinity from just beyond 7 to 14. Also Acids and Bases.
Phosgene
Colorless choking gas having an odor of new-mown hay or fresh corn; causes choking and coughing, and injuries to the lungs.
Photoelectric Cell
Photoelectric cell or photocell, a device whose electrical characteristics (e.g., current, voltage, or resistance) vary when light is incident upon it. Common photoelectric cells consist of two electrodes separated by a light-sensitive Semiconductor material. A battery or other voltage source connected to the two electrodes sets up a current even in the absence of light; when light strikes the semiconductor section of the photocell, the current increases in proportion to the light intensity. Photocells can be used to operate Switches, Relays, door openers, and intrusion alarms. See also Photovoltaic Cell.
Photometry
Photometry, branch of physics dealing with the measurement of the intensity of light sources. Instruments used for such measurements are called photometers; most types are based on the comparison of the light source to be measured with a light source of known intensity. The modern unit, adopted in 1948, for the measurement of light intensity is the candela (cd); it is equal to 1/60 of the intensity of one square centimeter of a blackbody radiator at the temperature at which platinum solidifies (2046°K).
Photon
Photon or light quantum, the particle composing light and other forms of electromagnetic radiation. The Photovoltaic Effect and blackbody radiation can be explained only by assuming that light energy is transferred in discrete packets, or photons, and that the energy of each photon is equal to the frequency of the light multiplied by Planck's constant h. Light imparts energy to a charged particle when one of its photons collides with the particle. Also Quantum Theory.
Photovoltaic Cell
A Semiconductor diode that converts light to electric current. When light strikes the exposed active surface, it knocks electrons loose from their sites in the crystal. Some of the electrons have sufficient energy to cross the ˜E_ Diode junction and pass through an external circuit. Because the current and voltage obtained from these devices are small, they are usually connected in large series-parallel arrays. Practical photovoltaic cells are currently about 10 to 15% efficient. Although cells constructed from indium phosphide and gallium arsenide are, in principle, more efficient, silicon-based cells are generally less costly. Solar photovoltaic cells have long been used to provide electric power for spacecraft. Recent developments, still in progress, have driven costs down to the point where they are being used more and more as terrestrial energy sources.
Picric Acid
1) Material to be added.
2) (Trinitrophenol). High explosive, more powerful than trinitrotoluene, used widely in the form of mixtures with other nitro compounds.
Piezoelectric Crystal
Crystalline material s constituted that, when it is mechanically compressed or stretched in certain directions, electrical charges in direct proportion to the mechanical strain appear on the crystal surfaces.
Pin Puller
A mechanical device in which a pressure cartridge causes a pin or piston to retract, usually against a side load.
Pin Pusher
A mechanical device in which a pressure cartridge drives a pin or piston along its central axis.
Piobert’s Law
Expression of the linearity of burning of homogeneous propellants. As any exposed propellant surface receives heat from the surrounding combustion products at the same rate, it, therefore, burns at the same rate. The burning surface thus recedes by parallel layers.
Pitch (of rifling)
Reciprocal of the twist. Twist.
Placards
Signs placed on vehicles transporting hazardous materials (including explosive materials) indicating the nature of the cargo.
Planet
Any of the nine relatively large, nonluminous bodies - Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto - that revolve around the sun (see Solar System). By extension, any similar body discovered revolving around another star would be called a planet. The Asteroids are sometimes called minor planets. The major planets are classified either as inferior, with an orbit between the sun and the orbit of the earth (Mercury and Venus), or as superior, with an orbit beyond that of the earth (Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto). The terrestrial planets - Mercury, Venus, Earth, and Mars - resemble the earth in size, chemical composition, and density. The Jovian planets - Jupiter, Saturn, Uranus, and Neptune - are much larger in size and have thick, gaseous atmospheres and low densities. Pluto is unclassified. The rapid rotation of the latter planets results in polar flattening of 2 - 10%, giving them an elliptical appearance.
Planform
Shape of plan view of fins.
Plasma
Plasma, in physics, a fully ionized gas containing approximately equal numbers of positive and negative Ions A plasma is an electric conductor and is affected by magnetic fields. The study of plasmas, called plasma physics, is important in efforts to produce a controlled thermonuclear reaction ( Nuclear Energy. In nature, plasmas occur in the interior of stars and in interstellar gas, making plasma a form of matter in the universe ( States of Matter)).
Plastic
Plastic, any synthetic organic material that can be molded under heat and pressure into a shape that is retained after the heat and pressures are removed. There are two basic types of plastic: thermosetting, which cannot be resoftened after being subjected to heat and pressures; and thermoplastic, which can be repeatedly softened and reshaped by heat and pressure. Plastics are made up chiefly of a binder consisting of long chainlike molecules called Polymers. Binders can be natural materials, e.g., Cellulose, or (more commonly) synthetic Resins, e.g., Bakelite. The permanence of thermosetting plastics is due to the heat- and pressure-induced cross-linking reactions the polymers undergo. Thermoplastics can be reshaped because their linear or branched polymers can slide past one another when heat and pressure are applied. Adding plasticizers and fillers to the binder improves a wide range of properties, e.g., hardness, elasticity, and resistance to heat, cold, or acid. Adding Pigments imparts color. Plastic products are commonly made from plastic powders. In compression molding, heat and pressure are applied directly to the powder in the mold cavity. Alternatively, the powder can be plasticized by outside heating and then poured into molds to harden (transfer molding); be dissolved in a heating chamber and then forced by a plunger into cold molds to set (injection molding); or be extruded through a die in continuous form to be cut into lengths or coiled (extrusion molding). The first important plastic, celluloid, has been largely replaced by a wide variety of plastics known by such trade names as Plexiglas, Lucite, Polaroid, and cellophane. New uses continue to be found and include contact lenses, machine gears, and artificial body parts. The widespread use of plastics has led to environmental problems. Because plastic products do not decay, large amounts accumulate as waste. Disposal is difficult because they melt when burned, clogging incinerators and often emitting harmful fumes, e.g., the hydrogen chloride gas given off by Polyvinyl Chloride. Also ™DE_ Polypropylene; Polyurethanes; Teflon.
Plastic Explosives
1)
High-brisance crystalline explosives, such as RDX or Octogen, can be embedded in curable or polyadditive plastics such as polysulfides, polybutadiene, acrylic acid, polyurethane, etc. The mixture is then cured into the desired shape. Other components such as aluminum powder can also be incorporated. The products obtained can be of any desired size, and specified mechanical properties can be imparted to them, including rubber-like elasticity ( LX and PBX). They can also be shaped into foils.
2) “Plastic” ® also means mixtures of RDX with Vaseline or gelatinized liquid nitro compounds of plastiline-like consistency. Explosive which, within normal ranges of atmospheric temperature, is capable of being molded into desired shapes. These explosives are easy to use by non-experts.
3) Also used propellant charges for rockets and guns have also been developed by compounding solid explosives such as nitramines (e.g. Cyclonite) with plastics. Plastic explosives and plastic propellants are of interest, if low thermal and impact sensitivity is needed ( “Lova”; Armour Plate Impact Test; Friction Sensitivity; Heat Sensitivity; Impact Sensitivity; Projectile Impact Sensitivity; Susan Test).
Plasticizer
A material added to a propellant to increase flexibility or workability.
Platform Breaching
Breaching of a mobile structure such as an aircraft, oil rig, ship, train, bus, etc.
Plunging Fire
Gunfire that strikes the earth's surface at a high angle.
Plutonium
Plutonium (Pu), radioactive element, first produced artificially by Glenn Seaborg and colleagues in 1940 by deuteron bombardment of uranium oxide. It is a silver-gray Transuranium Element in the Actinide Series. Plutonium is a fission fuel for Nuclear Energy and weapons ( Atomic Bomb; Nuclear Energy). It is an extremely dangerous poison, collecting in bones and altering the production of white blood cells. Element; Periodic Table.
Point-Blank Range
Distance, to a target, that is so short that the trajectory of a bullet or projectile is practically a straight rather than a curved line.
Point Detonating Fuze
Fuze, located in the nose of a projectile, which is initiated upon impact.
Polymer
A chemical compound with high molecular weight consisting of a number of structural units linked together by covalent bonds. The simple molecules that may become structural units are themselves called monomers. A structural unit is a group having two or more bonding sites. In a linear polymer, the monomers are connected in a chain arrangement and thus need only have two bonding sites. When the monomers have three bonding sites, a nonlinear, or branched, polymer results. Naturally occurring polymers include cellulose, proteins, natural rubber, and silk; those synthesized in the laboratory have led to such commercially important products as Plastics, synthetic fibers, and synthetic rubber.
Polypropylene
Lightweight Plastic, a Polymer or propylene. It is less dense than water and resists moisture, oils, and solvents. It is used to make packaging material, textiles, luggage, ropes that float, and, because of its high melting point (250°F/121°C), objects that must be sterilized.
Polyvinyl Chloride
(PVC), thermoplastic that is a Polymerof vinyl chloride. By adding plasticizers, hard PVC resins can be made into a flexible, elastic Plastic, used as an electrical insulator and as a coating for paper and cloth in making fabric for upholstery and raincoats.
Polyurethanes
Large group of Plastics that occur in a wide variety of forms. As a flexible foam, it is used for cushions and carpet backings. As a rigid foam, it can be molded into furniture or used as insulation. Some polyurethanes are highly elastic, e.g., Lycra, a fiber used in stretch clothing; others form hard protective coatings.
Population
All the items or devices about which conclusions are to be made.
Positive Duration
Time elapsing between the arrival of the shock front and the arrival of the part in which the pressure is exactly atmospheric.
Positive Impulse
Average pressure during the positive phase multiplied by the positive duration.
Potassium
Potassium (K), metallic element, discovered in 1807 by Sir Humphrey Davy, who decomposed potash with an electric current. It is a soft, silver-white, extremely reactive Alkali Metal. Potassium is the seventh most abundant element in the earth's crust and the sixth most abundant of the elements in solution in the oceans. It is an essential nutrient for plants and animals. Potassium compounds are used in fertilizers, soaps, explosives, glass, baking powder, tanning, and water purification. Element; Periodic Table.
Potassium Chlorate
Potassium chlorate is sparingly soluble in cold water, readily soluble in hot water, and insoluble in alcohol.
It is the principal component of Chlorate Explosives and is an important component of primer formulations and pyrotechnical compositions, in particular matchheads.
Potassium Nitrate
Potassium nitrate is readily soluble in water, sparingly soluble in alcohol, and insoluble in ether.
It is used as a component in pyrotechnical compositions, in industrial explosives, and in black powder.
Potassium Percholate
Potassium perchlorate is insoluble in alcohol but soluble in water. It is prepared by reacting a soluble potassium salt with sodium perchlorate or perchloric acid. It is employed in pyrotechnics.
Potential, Electric
Potential, electric, work per unit electric charge expended in moving a charged body from a reference point to any given point in an electric field. The potential at the reference point is considered to be zero, while the reference point itself is usually chosen to be at infinity. The change in potential associated with moving a charged body is independent of the actual path taken and depends only on the initial and final points. Potential is measured in Volts and is sometimes called voltage. Also Electric Circuit ; Electromotive Force.
Potentiometer
Potentiometer, or voltage divider, manually adjustable variable electrical resistor that has a Resistance element attached to an Electric Circuit by three contacts, or terminals. The ends of the resistance element are attached to the two input voltage conductors of the circuit, and the third contact, attached to the output of the circuit, is usually a movable terminal that slides across the resistance element, dividing it into two resistors. Because the position of the movable terminal determines what percentage of the input voltage ( Potential, Electric) is applied to the circuit, a potentiometer can be used to vary the magnitude of the voltage, e.g., in radio volume and television brightness controls.
Powder
1.) An explosive (or propellant) in the form of powder or small granules.
2.) A synonym designating any explosive, irrespective of type.
Powder Factor
The amount of explosive used per unit of rock; Also called Explosive Loading Factor.
Power
Power, in physics, the time rate of doing Work or of producing or expending Energy. The unit of power in the Metric System is the watt, which equals 1 joule per second. It is also the amount of power that is delivered to a component of an electric circuit when a current of 1 ampere flows through the component and a voltage of 1 volt exists across it. The English Unit Of Measurement is the horsepower, which equals 550 foot-pounds per second or 746 watts.
Power, (electric)
Power, electric, is the rate per unit of time at which Energyis consumed or produced. Electric Power is usually measured in watts or kilowatts (1,000 watts). The energy supplied by a current to an appliance enables it to work or to provide other forms of energy such as light or heat. The amount of electric energy an appliance uses is found by multiplying its power rating by the operating time. Units of electric energy are usually watt-seconds (joules), watt-hours, or kilowatt-hours (the choice for commercial applications). Generally, practical electric-power-generating systems convert mechanical energy into electric energy (see Generator). Whereas some electric plants obtain mechanical energy from moving water (water power or hydroelectric power), the vast majority derive it from heat engines in which the working substance is steam generated by heat from combustion of fossil fuels or nuclear reactions ( Nuclear Energy; Nuclear Reactor). Although the conversion of mechanical energy to electric energy may approach 100% efficiency, the conversion of heat to mechanical energy is about 41% efficient for a fossil-fuel plant and about 30% for a nuclear plant. It is thought that a magnetohydrodynamic generator, which operates by using directly the kinetic energy of gases produced by combustion, would have an efficiency of about 50%. Although Fuel Cells develop electricity by direct conversion of hydrogen, hydrocarbons, alcohol, or other fuels, with an efficiency of 50 to 60%, their high cost has restricted their use to space programs. Solar Energy has been recognized as a feasible power source. It can be exploited through wind turbines, Photovoltaic Cells, and heat engines, as well as through both conventional and low-head hydroelectric power plants. Research and development is bringing down the costs. An important problem in utilizing solar energy is related to the variable nature of sunlight and wind. To minimize energy losses from heating of conductors and to economize on the material needed for conductors, electricity is usually transmitted at the highest voltages possible. As modern Transformersare virtually loss free, the necessary steps upward or downward in voltage are easily accomplished. Electric utilities producing power are tied together by transmission lines into large systems called power grids. They are thus able to exchange power, so that a utility with low power demand can assist another with a high demand. See also Energy Sources Of.
 
 
Power Source
The source of power for energizing electric blasting circuits, e.g., a blasting machine or power line.
Powder Train
1) Train, usually of compressed black powder, used to obtain time action in older fuze types.
2) Train of explosives laid out for destruction by burning.
Practice Ammunition
Ammunition used for target practice; ammunition with a propelling charge, but with either an inert filler or a low-explosive filler to serve as a spotting charge.
Precision
The quality of having small dispersion about the mean.
Precession
A change in the direction of the axis of a rotating body.
Preignition
The spontaneous and premature ignition.
Premature Firing
The detonation of an explosive charge before the intended time.
Pressure
When a force acts perpendicular to a surface, the pressure (p) exerted is the ratio between the magnitude of the force and the area of the surface:
pressure = force / area Undisplayed Graphic
pressures are properly expressed in pascals, Pa (=N/m2), and may well be expressed using other terms such as bars, atmospheres or dynes.
Pressure Cartridge
An explosive item designed to produce momentary gaseous products of combustion under pressure for performing a mechanical operation.
Pressure, Center Of
The point where the resultant force caused by air resistance intersects the axis of the projectile.
Prevalves
One-way, one-shot, leak proof valves which, when open, permit the propellant to reach the turbopumps preliminary to engine ignition.
Prilled Ammonium Nitrate
Ammonium nitrate in a pelleted or prilled form.
Prills
Cellular sub-globular particles of AN formed by spraying concentrated AN solution against a stream of air.
Primacord
Flexible fabric tube containing a filler of high-explosive that is used to transmit a detonation from a detonator to a booster or bursting charge. Primacord is the trade name for one type of detonating fuse currently in use.
Primary Blast
A term used in commercial blasting to describe a blast used to fragment and displace material from its original position to facilitate subsequent handling and crushing.
Primary Explosive
1) A sensitive explosive that nearly always detonates by simple ignition from such means, are spark, flame, impact, friction, or other primary heat sources of appropriate magnitude.
2) A sensitive explosive, one of the first elements in an explosive train.
Primary Fragmentation
Fragments produced directly from the contents or casing of an explosive device.
Primer
1) A unit, package, or cartridge of explosives used to initiate other explosives or blasting agents, and which contains, a detonator, or detonating cord to which is attached a detonator designed to initiate the detonating cord.
2) Device used to initiate the functioning of an explosive or igniter train. It may be actuated by friction, flow, heat, pressure or electricity.
Primer-Detonator
Assembly consisting of a primer and a detonator. It may also include a delay element
Primer (Primer Mixture)
An explosive mixture containing a sensitive explosive, usually the first element in an explosive train.
Primer Seat
Primer location within the breech chamber of a gun that uses separate loading ammunition.
Probability
The ratio of the number of favorable events divided by the total number of events possible.
Probable Error
An error of such magnitude that the probability of making an error greater than it in any given observation is just equal to the probability of making one less than it, both probabilities being one-half.
Probate Analysis
A statistical analysis using a limited number of samples to determine a reliability factor. In this test, the level of variable is changed in a certain predetermined manner.
Procedure, Design
Outline of steps to follow in designing an item.
Product Lot Sampling
Tests conducted on a sample of a production lot to determine that the lot meets the specified dimensional and firing characteristics.
Progressive Burning
The burning of a propellant grain in which the reacting surface area increases during the combustion.
Progressive Granulation
Propellant grain which burns with a continually increasing surface until the grain is completely consumed.
Projectile
Object, such as a bullet or shell, that is propelled from a weapon by an explosive propelling charge.
Projectile Impact Sensitivity
The projectile impact sensitivity is the reaction of an explosive charge if hit by infantry projectiles. Impact safety is given if the charge does not fully explode at impact. The projectile impact sensitivity does not only depend on the type of explosive itself, but also on the nature of its confinement (metallic, plastic, thin-walled, or thick-walled). A single bullet impact by an ordinary or a hard steel cored projectile, or a machine gun burst, will create different reactions.
A test has been developed in Sweden: cylinders made of copper, brass, and aluminum (15 mm Æ) are brought to accurately adjusted and measured impact velocities. Also Impact Sensitivity.
Proof Ammunition <bob>
Ammunition incorporating solid, blunt-nosed, steel or cast iron shot of inexpensive manufacture; used in proof firing of guns; used to simulate the weight of projectile designed for the gun in adjusting the charge weight or propellant.
Propaganda Shell
Leaflet Shell.
Propagation
The detonation of explosive charges by an impulse received from adjacent or nearby explosive charges.
Propane
Propane (CH3CH2CH3), colorless gaseous Hydrocarbons that occurs in Natural Gas and Petroleum. Propane is sold compressed in cylinders, often mixed with other hydrocarbons, and is used as fuel in lamps, gas grills, certain home and portable stoves, and certain cigarette lighters.
Propellant
1.) Explosive material whose rate of combustion is low enough, and its other properties suitable, to permit its use as a propelling charge.
2.) An explosive substance or mixture of substances which, when burned, produces gases to provide energy.
Propellant Actuated Device (PAD)
A mechanical device actuated by a contained or inserted propellant charge.
Propellant Composite
Propellant compositions commonly contain additives which affect the performance of the propellant.
Propellant Double Base
The double-base propellant consists of nitrocellulose and nitroglycerin with the addition of various stabilizers.
Propellant Explosive
An explosive material that normally functions by deflagration and is used for propulsion purposes. It may be a Class A or Class B explosive, depending upon its susceptibility to detonation.
Propelling Charge
Explosive charge that is burned in a weapon to propel a projectile therefrom ( Propellant). Burning of the confined propelling charge produces gases whose pressure forces the projectile out.
Proper Motion
Proper motion (M), apparent angular motion of a star on the celestial sphere, usually measured in seconds of arc per year. A star's transverse velocity VT i.e., its motion across the line of sight to the star (as opposed to its RADIAL Velocity, or line-of-sight velocity), is calculated in kilometers per second from the equation VT = 4.74 M/p , where p is the star's Parallax, expressed in seconds of arc.
Protein
Protein, any of the group of highly complex organic compounds found in all living cells. Protein is the most abundant class of all biological molecules, comprising about 50% of cellular dry weight. Classified by biological function, proteins include the enzymes, which catalyze cellular reactions; collagen, keratin, and elastin, which are structural, or support, proteins; hemoglobin and other transport proteins; casein, ovalbumin, and other nutrient proteins; antibodies, which are necessary for immunity; protein hormones, which regulate metabolism; and proteins such as actin and myosin, the contractile muscle proteins, that perform mechanical work. Structurally, proteins are large molecules composed of one or more chains of varying amounts of the same 22 amino acids, which are linked by peptide bonds. Each protein is characterized by a unique and invariant amino acid sequence. Protein chains may contain hundreds of amino acids; some proteins also incorporate phosphorus or such metals as iron, zinc, and copper. The amino acid sequence also determines the molecule's three-dimensional structure; this so-called native state is required for proper biological function. The information for the syntheses of the specific amino acid sequences from free amino acids is carried by the cell's nucleic acids.
Proton
Proton, Elementary Particle having a single positive electrical charge and constituting the nucleus of the ordinary hydrogen Atom. Every atomic nucleus contains one or more protons. The mass of the proton is about 1,840 times the mass of the Electron and slightly less than the mass of the neutron. In 1919 Ernest Rutherford discovered the proton as a product of the disintegration of the atomic nucleus. The proton and the neutron are regarded as two aspects, or states, of a single entity, the nucleon. The antiproton, the proton's antiparticle ( Antimatter), was discovered in 1955.
Prototype
The first fully workable item; also a precursor of later developments.
Proximity Fuze
Fuze designed to detonate a projectile, bomb, mine, or charge when activated by an external influence in the close vicinity of a target.
Pyro Powder
Straight nitrocellulose powder; smokeless propelling charge consisting of a nitrocellulose that has a smaller nitrogen content than guncotton; single-base propellant.
Pyrocellulose
Nitrocellulose containing 12.60 percent nitrogen.
Pyrochemical
To be used (with discretion) in lieu of pyrotechnical, especially in regard to the chemical reactions of pyrotechnics.
Pyrocore
A flexible explosive cord similar to MDF except that the high explosive core is modified to promote ignition at the speed of detonation. A high velocity ignition propagation fuse (detonating).
Pyrocotton
Pyrocellulose.
Pyrogen
A rocket ignition system containing a solid propellant gram as its main ignition material.
Pyrotechnic
A mixture of chemicals designed to produce heat, light, smoke, gas or noise.
Pyrotechnics
Any combustible or explosive compositions or manufactured articles designed and prepared for the purpose of producing audible or visible effects. Pyrotechnics are commonly referred to as fireworks.
Pyroxylin (Collodion)
Nitrocellulose containing 8-12 percent nitrogen.

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