Explosives processing techniques

Processing of an explosive is performed by one of the following techniques depending upon the caliber of weapon, particle size of the explosive and quantity involved. The general outlines of the processing techniques are given here. 

Chemical and physical processing techniques for ferroelectric thin films have undergone explosive advancement in the past few years (see Ref. 1, for example). The use of PZT (PbZri- cTi c03) family ferroelectrics in the nonvolatile and dynamic random access memory applications present potentially large markets [2]. Other thin-film devices based on a wide variety of ferroelectrics have also been explored. These include multilayer thin-film capacitors [3], piezoelectric or electroacoustic transducer and piezoelectric actuators [4-6], piezoelectric ultrasonic micromotors [7], high-frequency surface acoustic devices [8,9], pyroelectric intrared (IR) detectors [10-12], ferroelectric/photoconduc-tive displays [13], electrooptic waveguide devices or optical modulators [14], and ferroelectric gate and metal/insulator/semiconductor transistor (MIST) devices [15,16]. 

Improvements in threshold applications of IMS have arisen from improved sampling methods, more sensitive and rugged instrumentation, and better data-processing techniques. These are seen with advances in the detection of explosives with handheld as well as with fixed or stationary analyzers. Parallel advances have occurred with instrumentation and procedures requiring quantitative determinations. These have occurred with the increased availability of drift tubes that exhibit fast response, low memory effects, and reproducible delivery of sample to the ion source. Together, these applications have resulted in enhanced precision, sensitivity, and linear range compared with previous generations of analyzers. 

Glenn and Orts [153] describe another technique for making starch-based foams using a compression-explosion process. Starch feedstock is compressed in a heated mould at 230 °C under a 3.5 MPa clamping force for 10 s, which is then... 

The number of situations in which ignition can be reliably prevented by the avoidance of ignition sources are limited. Situations where prevention is viable include batch reaction processes and isolated liquid storage. However, it is good practice to ensure that all reasonable measures are implemented to eliminate the development of sources of ignition. This is particularly important when using an explosion protection technique in order to minimise down time and unnecessary refurbishment of the system which can be costly. 

Cherian et al. [119] also extracted cellulose nanofibres from pineapple leaf fibres using acid-coupled steam treatment. The strucmral and physicochemical properties of the pineapple leaf fibres were studied by environmental scanning electron microscopy (ESEM), AFM and TEM and X-ray diffi action (XRD) techniques. The acid-coupled steam explosion process resulted in the isolation of PALF nanofibres having a diameter range of 5-60 nm. Figure 1.24a and b shows the AFM and TEM images of nano fibres obtained from pineapple leaf fibres. AFM and TEM support the evidence for the isolation of individual nanofibres from PALF. 

Following the discovery of TFE homopolymerization by Dr Roy Plunkett, the commercial development of PTFE required enormous effort Among the major obstacles that had to be overcome were the explosion hazard associated with TFE handling, its tendency to form extremely dai erous polymeric peroxides and the requlr ents for specialized processing techniques This effort, coming as it did in the midst of the second World War, not only occupied all available resources, but strongly Inhibited the normal Inclination to search for alternative solutions to the problem of polymer intractability. 

Destructive Testing. Destmctive testing is used to determine the strength of the weld and the effect of the explosion-welding process on the parent metals. Standard testing techniques can be utilized on many composites however, nonstandard or specially designed tests often are required to provide meaningful data for specific appHcations. 

Vessel heads can be made from explosion-bonded clads, either by conventional cold- or by hot-forming techniques. The latter involves thermal exposure and is equivalent in effect to a heat treatment. The backing metal properties, bond continuity, and bond strength are guaranteed to the same specifications as the composite from which the head is formed. AppHcations such as chemical-process vessels and transition joints represent approximately 90% of the industrial use of explosion cladding. 

Microscopists in every technical field use the microscope to characterize, compare, and identify a wide variety of substances, eg, protozoa, bacteria, vimses, and plant and animal tissue, as well as minerals, building materials, ceramics, metals, abrasives, pigments, foods, dmgs, explosives, fibers, hairs, and even single atoms. In addition, microscopists help to solve production and process problems, control quaUty, and handle trouble-shooting problems and customer complaints. Microscopists also do basic research in instmmentation, new techniques, specimen preparation, and appHcations of microscopy. The areas of appHcation include forensic trace evidence, contamination analysis, art conservation and authentication, and asbestos control, among others. 

Fire and Explosion Prevention. Prevention of fire and explosion takes place in the design of chemical plants. Such prevention involves the study of material characteristics, such as those in Table 1, and processing conditions to determine appropriate ha2ard avoidance methods. Engineering techniques are available for preventing fires and explosions. Containment of flammable and combustible materials and control of processes which could develop high pressures are also important aspects of fire and explosion prevention. 

Another process involves explosive bonding. The corrosion-resistant metal is bonded to a steel backing metal by the force generated by properly positioned explosive charges. Relatively thick sections of metal can be bonded by this technique into plates. 

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