Explosives basic characteristics

Merzhanov Dubovitskii (Ref 4) formulated a general theory for the thermal explosion of condensed expls, which takes into consideration the removal of particles from the reaction volume. This theory makes it possible to calc all the basic characteristics of thermal explosion such as critical conditions, depth of preexplosion decompn induction period "Detonation is Condensed Explosives is the title of a book by J. Taylor (Ref 3) who discusses in detail the various aspects of the subject. See also studies reports listed as Refs 2, 5 6 Refs 1)L.D.Landau K.P.Stanyukovich, Dokl-AkadN 46, 396-98 (1945) 47, No 4, 273 76 (1945) CA 40, 4523 4217 (1946) 2)G.Morris... 

In spite of the explosion in studies on ionic liquids (ILs), there is only a small number of studies of their basic characteristics. There are limitless possibilities for the design of ILs by changing their component ion structures. However, the chance of succes s is not very great without accurate information on the structure-properties relationship. Physico-chemical property data for ILs are therefore very important for the present and future ofthe field of ILs. In this chapter, some basic properties of air-stable ILs have been summarized. Some are not directly related to electrochemistry but are very important and useful for a wide range of science and technology related to ILs. 

By the multidisciplinary theory and method of statistical analysis and case analysis, basic characteristics and rule of coal-gas dynamic disasters accidents in coal mines during 2001-2012 period were studied and the incentive control on ignition source of direct causes of gas explosion accidents were analyzed, so as to explore the approaches from the control of ignition sources for governance coal-gas dynamic disasters. 

The years since the 1930s have seen extensive research and development in polymer chemistry, and an almost explosive growth in plastics, coatings, and rubber technology has created a worldwide multibillion-dollar industry. A few basic characteristics account for this phenomenal growth. First, the raw materials for synthetic polymers are derived mainly from petroleum. With the development of... 

Accident scenarios leading to vapor cloud explosions, flash fires, and BLEVEs were described in the previous chapter. Blast effects are a characteristic feature of both vapor cloud explosions and BLEVEs. Fireballs and flash fires cause damage primarily from heat effects caused by thermal radiation. This chapter describes the basic concepts underlying these phenomena. 

Potential explosion phenomena include vapor cloud explosions (VCEs), confined explosions, condensed-phase explosions, exothermic chemical reactions, boiling liquid expanding vapor explosions (BLEVEs), and pressure-volume (PV) ruptures. Potential fire phenomena include flash fires, pool fires, jet fires, and fireballs. Guidelines for evaluating the characteristics of VCEs, BLEVEs, and flash fires are provided in another CCPS publication (Ref. 5). The basic principles from Reference 5 for evaluating characteristics of these phenomena are briefly summarized in this appendix. In addition, the basic principles for evaluating characteristics of the other explosion and fire phenomena listed above are briefly summarized, and references for detailed evaluation of characteristics are provided. 

Corrosivity is that characteristic of chemicals that exhibits extremes of acidity or basicity or a tendency to corrode steel. Such chemicals, used in various refining (treating) processes, are acidic and are capable of corroding metal such as tanks, containers, drums, and barrels. On the other hand, reactivity is a violent chemical change (an explosive substance is an obvious example) that can result in pollution and/or harm to indigenous flora and fauna. Such wastes are unstable under ambient conditions insofar as they can create explosions, toxic fumes, gases, or vapors when mixed with water. 

The basic equations for describing the detonahon characteristics of condensed materials are fundamentally the same as those for gaseous materials described in Sections 3.2 and 3.3. The Rankine-Hugoniot equations used to determine the detonation velocities and pressures of gaseous materials are also used to determine these parameters for explosives. Referring to Sechon 3.2.3, the derivative of the Hugoniot curve is equal to the derivative of the isentropic curve at point J. Then, Eq. (3.13) be-... 

Whatever system may be developed, the basic objective is the same. Different technologies may be employed, but the reason for the system is always to locate and identify explosive molecules in air, water or soil, or on a surface, in order to pinpoint the source of these molecules. Ideally, the source is located before it can be actuated in a harmful way. Consequently, every system developed for this purpose will have some characteristics in common with any other developed for the same purpose. Therefore, it is valuable to consider those common elements in a general way. 

Studies on artificial ion channels are expected to provide important information on molecular mechanisms and to deepen our understanding of natural ion channels through the establishment of a detailed structure-function relationship. At the same time, the research will contribute to the fascinating area of nanoscale transducers, and may eventually lead to the development of so-called molecular ionics. Here, the author would like to describe the basic concept for the molecular design of various artificial ion channels and to compare their characteristics in the hope of stimulating a future explosion of this research field. Special attention is focused on non-peptidic approaches. Helical bundle approaches " and studies on modified antibiotics " are beyond the scope of this review. 

During this same period the basic theoretical concepts were formed. Properties common to all explosive mixtures—the ability to ignite when heated, the ability to propagate flame after local ignition—were explained on the basis of common characteristics of explosive mixtures—the presence in them of a large supply of chemical energy. For a qualitative explanation of combustion phenomena it is sufficient to know that at low temperatures explosive compounds are inert, and no heat of reaction is released rapid chemical reaction begins only at elevated temperatures. 

What problems face the theory of combustion The theory of combustion must be transformed into a chapter of physical chemistry. Basic questions must be answered will a compound of a given composition be combustible, what will be the rate of combustion of an explosive mixture, what peculiarities and shapes of flames should we expect We shall not be satisfied with an answer based on analogy with other known cases of combustion. The phenomena must be reduced to their original causes. Such original causes for combustion are chemical reaction, heat transfer, transport of matter by diffusion, and gas motion. A direct calculation of flame velocity using data on elementary chemical reaction events and thermal constants was first carried out for the reaction of hydrogen with bromine in 1942. The problem of the possibility of combustion (the concentration limit) was reduced for the first time to thermal calculations for mixtures of carbon monoxide with air. Peculiar forms of propagation near boundaries which arise when normal combustion is precluded or unstable were explained in terms of the physical characteristics of mixtures. 

The job of a chemical munition is to create a toxic environment over as much of the target as is compatible with the toxicity of its charge. It must convert its bulk load either into an even distribution of liquid or solid particles, or into a cloud of vapour, or into both. It must, additionally, do this in a certain time. These are strict demands, and they are made more severe by the diversity of chemical agents now in stockpiles. Each agent has a combination of physical characteristics and toxic behaviour that is unique but, nevertheless, all munitions work on the same basic principle they cause the transfer of energy from a store, generally an explosive, to the chemical load. The simplest chemicals to disperse are the volatile, non-persistent ones such as phosgene the hardest ones... 

The basic method of distillation (ASTM D-86) is one of the oldest methods in use because the distillation characteristics of hydrocarbons have an important effect on safety and performance, especially in the case of fuels and solvents. The boiling range gives information on the composition, the properties, and the behavior of petroleum and derived products during storage and use. Volatility is the major determinant of the tendency of a hydrocarbon mixture to produce potentially explosive vapors. Several methods are available to define the distillation characteristics of petroleum and its various petroleum products. In addition to these physical methods, other test methods based on gas chromatography are also used to derive the boiling point distribution of a sample (ASTM D-2887, ASTM D-3710, ASTM D-5307, ASTM D-6352). 

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