Strawboard has been utilised as a fragmentation capture material since the 1960s, mainly employed to capture fragments from explosives and explosive devices from arena trials of munitions. As this material has historically been calibrated to a known standard, it has a proven record of allowing research establishments to ascertain the velocity of a fragment based on the depth of penetration of the strawboard. During the time of calibration, strawboard was used as a common building material which was both widely available and relatively affordable; however, due to the recent economic crisis and geopolitical supply issues, this is no longer the case.
View Article and Find Full Text PDFThe International Tracing Instrument (ITI) is a document adopted by United Nations Member States in 2005, which outlines challenges faced in the tracing of illicit weapons and offers suggestions to increase the success of tracing operations. A key provision of the ITI states that serial numbers must be recoverable if obliterated. This research, therefore, investigates two methods of recovering laser engraved marks on steel, due to the increase in firearms manufacturing relying on lasers to apply critical markings.
View Article and Find Full Text PDFHigh pressure, high-temperature events need to be quantified experimentally. Where fragmentation occurs, i.e.
View Article and Find Full Text PDFIdentifying failure mechanisms in skeletal tissue allows a deeper understanding of the effects of specific projectile impacts on bone. While ballistic trauma in flat bones is largely researched, knowledge of how long bones react to gunshot impacts is limited in the literature. The impacts of deforming ammunition appear to produce higher levels of fragmentation; however, these have not been studied in depth.
View Article and Find Full Text PDFForensic Sci Med Pathol
March 2024
Crossbow-related injuries resulting in serious and mortal consequences have increased in recent years, and although significant research exists for both injury and fatality on the human body, limited data exists on the lethality of the bolt and the failure modes of protective materials. This paper concerns itself with the experimental validation of four differing crossbow bolt geometries, their effects on material failure and potentially lethality. During this study, four different types of crossbow bolt geometries were tested against two protection mechanisms that differed in mechanical properties, geometry, mass and size.
View Article and Find Full Text PDFImprovised explosive devices (IEDs) have generated over 137,000 civilian casualties in the past decade, more than any other explosive weapon system in the same period with a far-reaching impact on personal security freedoms across 50 affected countries. The aim of this paper is to consolidate existing risk management processes to control the availability of chemical precursors used in the manufacture of home-made explosives (HME) and to recommend global standards for market regulations in their composition, sale and use. This will be achieved by assessing the current regional regulations for three common chemical precursors (hydrogen peroxide, ammonium nitrate and potassium chlorate), and proposing a risk management process to identify key precursor chemicals that require greater control.
View Article and Find Full Text PDFThe present paper presents a scanning electron microscope (SEM) analysis of the genesis and microarchitecture of experimentally induced cortical entry fractures in porcine scapulae impacted at velocities ranging from 54 to 897 m/s. SEM observation was conducted on polyurethane replicas cast from negative silicone moulds. Analysis of the sequence of fracture processes operative during projectile impact revealed the presence of ring cracks at the site of impact, confirming that penetration in sandwich bones is achieved by cone crack propagation.
View Article and Find Full Text PDFFollowing observations of survival of microbes and other life forms in deep subsurface environments it is necessary to understand their biological functioning under high pressure conditions. Key aspects of biochemical reactions and transport processes within cells are determined by the intracellular water dynamics. We studied water diffusion and rotational relaxation in live Shewanella oneidensis bacteria at pressures up to 500 MPa using quasi-elastic neutron scattering (QENS).
View Article and Find Full Text PDFFacts concerning the stability and functioning of key biomolecular components suggest that cellular life should no longer be viable above a few thousand atmospheres (200-300 MPa). However, organisms are seen to survive in the laboratory to much higher pressures, extending into the GPa or even tens of GPa ranges. This is causing main questions to be posed concerning the survival mechanisms of simple to complex organisms.
View Article and Find Full Text PDFQuasielastic neutron scattering (QENS) is an ideal technique for studying water transport and relaxation dynamics at pico- to nanosecond timescales and at length scales relevant to cellular dimensions. Studies of high pressure dynamic effects in live organisms are needed to understand Earth's deep biosphere and biotechnology applications. Here we applied QENS to study water transport in Shewanella oneidensis at ambient (0.
View Article and Find Full Text PDFIn this work, the photocatalytic disinfection of Escherichia coli (E. coli) using dual layer ceramic wafers, prepared by a simple and low-cost technique, was investigated. Heterojunction wafers were prepared by pressing TiO2 and WO3 powders together into 2 layers within a single, self-supported monolith.
View Article and Find Full Text PDFMicroorganisms influence biogeochemical cycles from the surface down to the depths of the continental rocks and oceanic basaltic crust. Due to the poor recovery of microbial isolates from the deep subsurface, the influence of physical environmental parameters, such as pressure and temperature, on the physiology and metabolic potential of subsurface inhabitants is not well constrained. We evaluated Fe(III) reduction rates (FeRRs) and viability, measured as colony-forming ability, of the deep-sea piezophilic bacterium Shewanella profunda LT13a over a range of pressures (0-125 MPa) and temperatures (4-37∘C) that included the in situ habitat of the bacterium isolated from deep-sea sediments at 4500 m depth below sea level.
View Article and Find Full Text PDFThe survival of Shewanella oneidensis MR-1 at up to 1500 MPa was investigated by laboratory studies involving exposure to high pressure followed by evaluation of survivors as the number (N) of colony forming units (CFU) that could be cultured following recovery to ambient conditions. Exposing the wild type (WT) bacteria to 250 MPa resulted in only a minor (0.7 log N units) drop in survival compared with the initial concentration of 10(8) cells/ml.
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