Examples explosives analysis

Consequence analysis (for example, spill, leaks, vapour/liquid release modelling, fire radiation and pollutants dispersion studies, and explosion analysis)... 

Fire and explosion analysis is a complex topic, and one that uses sophisticated software. Specialist support is invariably needed to carry out this work. Nevertheless, professional understanding to do with fires and explosions is stiU limited. For example, the initial report from the Bimcefield explosion and fire that occurred in... 

There are few problems of praetleal interest that ean be adequately approximated by one-dimensional simulations. As an example of sueh, eertain explosive blast problems are eoneerned with shoek attenuation and residual material stresses in nominally homogeneous media, and these ean be modeled as one-dimensional spherieally symmetrie problems. Simulations of planar impaet experiments, designed to produee uniaxial strain loading eonditions on a material sample, are also appropriately modeled with one-dimensional analysis teehniques. In faet, the prineipal use of one-dimensional eodes for the eomputational analyst is in the simulation of planar Impaet experiments for... 

Sensitiveness to Flame. See under Ignition and Explosion of MeN by Flame Sensitiveness to Initiation. MeN is more sensitive, than NG. For example, when it is initiated with a No 1 cap, under w tamping, the detonation effectiveness is equal to 88% of that with a No 8 cap, while NG under the same conditions gives only 33% effectiveness Toxicity and Fire Explosion Hazards are briefly discussed in Refs 11 12 Uses It can be used as a gelatinizer of collod cotton in commercial expls, but its high volatility is objectionable (Ref 2, p 208). Has been used in some rocket propints (Refs 11 12) Method of analysis of MeN is described by Vandoni (Ref 10)... 

This chapter provides an example of the evaluation and retrofit of the masonry walls of an existing reinforced concrete framed building using the principles outlined in Chapter 10. The evaluation of the roof, structural framing and foundation are not covered in this example. The explosion magnitude and front wall blast load are determined by others. The analysis of the exterior walls, and upgrade options, arc presented in this example. 

The potential of ultrahigh-resolution mass spectrometry for the analysis of complex chemical mixtures is particularly illustrated by FT-ICR-MS which definitely sets a new standard. For example, ultrahigh-resolution was applied to separate several thousand components in crude oil, [85,86] fuels, [87,88] or explosion residues. [89]... 

Several examples illustrate the use of GC/MS for analysis of explosives Trace analysis of explosives in water by GC/MS was carried out using a cooled temperature-programmable injector and a 15 mx 0.255 (Xm ID, 0.25 (Xm film thickness, DB-1 column [7]. 

The following examples illustrate the range of apphcations of LC/MS for trace analysis of explosives ESI-LC/MS/MS-CID fragmentation processes of a series of nitroaromatic, nitramine and nitrate ester explosives were studied in the negative-ion mode using daughter-ion, parent-ion and neutral loss scans [14]. Table 1 shows the CID daughter ions in ESI-MS/MS of TNT. 

With a focus on trace forensic detection of explosives, especially for use in counterterrorism and to counter narcotics investigations, Fetterolf et al. [75] evaluated the use of ion mobility-mass spectrometry for explosives determinations. In this, explosives residues were collected on a membrane filter by a special attachment on a household vacuum cleaner. Although subsequent thermal desorption and analysis required only 5 s, fimits of detection for most common explosives were as low as 200 pg. The persistence of explosives on hands and transfer to other surfaces were also examined as were post-blast residues of NG on fragments of improvised explosive devices constructed with double-based smokeless powder. Finally, postblast residue from C-4, Semtex, and other explosives was found by IMS analyses on items of forensic and evidentiary value. These few out of many examples demonstrate that mobihty spectrometers are well suited tools for laboratory and on-site investigations, before and after the use of explosives. 

The first two points are best dealt with as part of the process for developing vahdated analytical methods. Vafidation should include testing the robustness of a method in repeated use over a period of time determining the precision and accuracy and study of potential interferences. As an example, it would be expected that in the capillary GC—TEA method for organic explosives, a peak should be at least three times the basefine noise to be counted as a real signal, and that the relative retention time should be within 1.0% of the standard for volatile compounds and within 0.5% for the rest. The relative retention time is simply the ratio of the analyte s retention time compared with that of an internal standard. Use of relative retention times significantly improves the repeatabdity of GC analysis... 

Collectively, the thermal analysis techniques can be used to compare different batches of gunpowder and its constituents or to make more fundamental studies of, for example, the stability of the explosive under various physical or chemical conditions. 

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