Restricted propellant

Oberflachenbehandlung = surface treatment also -> inhibited propellant - restricted propellant 191 273 305 Obturate 239... 

The popularity of aerosols has been declining. A widely used group of propellants, the fluorinated hydrocarbons, have been restricted in use since it was found that they can harm the environment by reducing the o2one layer of the upper atmosphere (see AiRPOLLUTlON ATMOSPHERIC MODELING Ozone). 

TSCA also placed restrictions on the use of chlorofluorocarbons, asbestos, and fuUy halogenated chlorofluoroalkanes such as aerosol propellants. 

We restrict ourselves to investigate an axial fan, where there is only an impeller. The incoming air has the direction of the axis of the propeller. 

Oil production requires pressure from compressed gas or water to expel oil to the surface. There arc three main types of rcsci voir drives to flush oil to wells dissolved gas drive, gas-cap drive, and water drive. With a gas drive, the oil in the reservoir is saturated with dissolved gas. As pressures fall with oil production, the gas escapes from solution, expands, and propels oil to the surface. Hence it is important to control gas production so it remains available to remove the oil. With a gas-cap drive, the upper part of the reseiwoh is filled with gas, and oil lies beneath it. As oil is withdrawn, the compressed gas expands downward, pushing oil to the well bore. As with a dissolved gas drive, gas production from the gas cap should be restricted to maintain reservoir pressure to expel the oil. Finally, with a water drive, the oil lies above a layer of water. The compressed water... 

A form of cooling, and the one of prime interest, concerns ablative cooling. It is essentially a heat and mass transfer process in which mass is expended to achieve thermal dissipation, absorption, and blocking. The process is passive in nature, serves to control the surface temperature, and greatly restricts the flow of heat into the material substrate. As a result of these desirable attributes, ablative cooling (includes use of plastic compositions) has been widely used for thermal protection of solid propellant motors and less extensively in liquid propellant motors. 

Concerned mainly with the security of explosives and restricted substances. Applicable to the acquisition, keeping, handling and control of explosives, e.g. blasting explosives, detonators, fuses, ammunitions, propellants, pyrotechnics and fireworks. 

The design of propellants for solid fuel rockets differs considerably from that for ordnance, because of the lower operating pressures, usually below 15 MPa. To understand the principles involved it is first necessary to give a brief account of rocket propulsion. In this account considerations will be restricted to motors based on solid propellants. Motors based on liquid fuels, such as petroleum fractions and liquid oxygen, depend on combustion processes of non-explosive type. 

OTS has focused its control efforts on two other chemicals in addition to PCBs. Working in conjunction with the Food and Drug Administration, EPA used TSCA s Section 6 to prohibit the use of chlorofluorocarbons (CFCs) as propellants in nonessential aerosol products. An advanced notice of proposed rulemaking under TSCA outlined approaches for restricting other uses of CFCs, but the attempt to deal with other CFC uses has been abandoned by the Reagan Administration. 

Specific bans on chemicals or uses have not been the most important outcome of TSCA. Only one type of chemical, PCBs, was specifically targeted in the original law and they are now outlawed in most of their uses. EPA administration of the law in its early years led to a ban of chlorofluorocarbons as aerosol propellants, restrictions on dioxin waste disposal, rules on asbestos use, and testing rules on chlorinated solvents. It has led to a central bank of information on existing commercial chemicals, procedures for further testing of hazardous chemicals, and detailed permit requirements for submission of proposed new commercial chemicals. 

Strands of this material would not burn in the inert atmosphere of the Crawford type bomb, but they burned in air at 70°F at the rate of 0.023" per second. This compared with a burning rate for H9 propellant of 0.097 /sec at 1 atm and 0.36"/sec,at 1000 psi 70°F This cast cellulose acetate material has been employed for end restricting 8W and 20" diameter perforated cast OGK grains and thermally cycled JATO motors at -65, +70, +165°F. No cracks or separations of the cast acetate restrictions were observed but some softening and deformation was noted. after conditioning at +165°F. These rounds functioned satisfactorily when fired at either -65 or +165°F... 

The strength of alcohol commonly used in the US is 95% (190 proof), while 96% is used in Europe. For prepn of perfumes the 70% alcobol is used. TTie so-called absolute alcobol (200 proof) is at least 99% and its use is restricted. to analytical purposes or research. The so-called industrial alcohol is unfit to drink because it contains up to 5% methanol (wood alcohol) or benzene. Such alcohol is known as denatured and it is briefly described in Vol 3 of Encycl, p D63-R. Denatured alcohol is used as a solvent for expls, rocket fuels, rubbers, detergents, etc. Mixture of 1 part alcobol with 2 parts eth (described in Vol 5 of Encycl as Diethyl Ether) used as a solvent in dehydration of Pyrocellulose in manuf of single-base propint, such as described in Davis (Ref 2) and also on p C399 of Vol 3 of Encycl, under "Colloiding Agents and Colloidal Propellants ... 

Mobile weapon systems include the ordnance weapon systems, such as the air-to-air, air-to-surface, surface-to-air, and short-range, surface-to-surface missile. Because of the limited volume requirements, heavy emphasis is placed on density impulse. These systems are completely prepackaged (including propellants) and require complete storability of the propellant as a liquid over a temperature range — 65°-160°F. Because of personnel proximity at all times, toxicity is sometimes an important factor. The large number of units which are utilized usually imposes restrictions on propellant cost. 

Nitroparaffins. Nitro-organics as a class of compounds are of greater interest in solid than liquid propellants. However, some nitroparaffins have been utilized in liquid systems. Nitromethane has been used as a monopropellant, while tetranitromethane, hexanitroethane, nitroform, and nitroform salts have been considered as oxidizing components in bipropellant systems. The high melting points of the latter and their sensitivity restrict their use to solutes in lower freezing, insensitive liquids. A solution of 70 wt. % C(N02)4 in N204 is an example of such a system and has been proposed as an oxidizer (3). 

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