Fire, generally penetration

Finally, we may point out that there is a possibility that even a nuclear war according to Scenario I, in which most NOx is deposited in the troposphere, may cause ozone depletions in the stratosphere, if the hot fires in the oil and gas production regions become so powerful that the fire plumes penetrate into the stratosphere. Another means of upward transport may occur when the heavy, dark aerosol layer, initially located in the troposphere, is heated by solar radiation and starts to set up convection and wind systems which will transport an appreciable fraction of the fire effiuents into the stratosphere. These speculative thoughts may be pursued further with currentiy available general circulation models of the atmosphere. 

The results of this program are contained in reference (10) Table II presents a comparison of the selected physicochemical properties of Sulphlex-233 and an AC-20 grade asphalt cement used in the FHWA study. The table indicates that their properties are generally quite different, particularly the specific gravity, penetration, viscosities, and flash and fire points. However, from a practical standpoint, as the materials are used in the field, these differences are not highly significant. 

In general, boric acid esters (also called borester) derived from alcohols and boric acid are hydrolytically unstable for general use in plastics/elastomers, wood, paper, or cotton. However, the pressure treating of wood with trimethylborate [B(OCH3)3] is reported to be effective in rendering it fire resistant.88 In this case, once trimethylborate penetrates the wood, it will revert back to boric acid. 

M52 FUZE. General. This standard fuze, (fig. 12), a super-quick type, is identified by PDF (point detonating fuze) M52 stamped on the body. This fuze is designed to function before any penetration occurs, permitting the maximum surface elTect of fragmentation of the shell. For use in the field, it is issued assembled to the shell as a part of the complete round. To prepare for firing it is only necessary to remove the safety wire. 

Penetrations of fire resistive walls and floors are made on the basis of practical necessity or engineering design. For MFL or fire walls, these penetrations should generally be avoided. 

This test also requires special equipment and generally consists of three parts a preliminary ignition test, a fire penetration test and a spread of flame test. The specimen is subjected to radiant heat and a vacuum is applied to one side to simulate service conditions. A specified flame is applied to the test piece for various durations and the time for the flame to penetrate, as well as the maximum distance of flame spread, are noted. Glowing, flaming or dripping on the underside of the specimen are also taken into consideration. Results are classified as follows ... 

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