13 research outputs found

    Imaging of compact objects buried in underwater sediments using electrical impedance tomography

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    A detailed study is undertaken to investigate the performance and phenomenology of electrical impedance tomography for underwater applications. Experiments are performed in an aquarium tank filled with water and a sediment layer. A 64-electrode square array, appropriately scaled down in size, and a previously developed data acquisition system are used. An evaluation is conducted of the ability to detect compact objects buried at various depths in the sediment, with different horizontal separations, and at various vertical separations between the electrode array and the sediment layer. The objects include metallic and nonmetallic mine-like objects and inert ammunition projectiles, all appropriately scaled down in size. The effects of a number of other physical factors are studied, including sediment type, water turbidity and salinity, and object coating integrity and rusting

    Observations on military exploitation of explosives detection technologies

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    Accurate and timely detection of explosives, energetic materials, and their associated compounds would provide valuable information to military commanders in a wide range of military operations: protection of fast moving convoys from mobile or static IED threats; more deliberate countermine and counter-IED operations during route or area clearance; and static roles such as hasty or deliberate checkpoints, critical infrastructure protection and support to public security. The detection of hidden explosive hazards is an extremely challenging problem, as evidenced by the fact that related research has been ongoing in many countries for at least seven decades and no general purpose solution has yet been found. Technologies investigated have spanned all major scientific fields, with emphasis on the physical sciences, life sciences, engineering, robotics, computer technology and mathematics. This paper will present a limited, operationally-focused overview of the current status of detection technologies. Emphasis will be on those technologies that directly detect the explosive hazard, as opposed to those that detect secondary properties of the threat, such as the casing, associated wires or electronics. Technologies that detect explosives include those based on nuclear radiation and terahertz radiation, as well as trace and biological detection techniques. Current research areas of the authors will be used to illustrate the practical applications. © 2011 SPIE

    Sister-chromatid exchange and chromosome aberrations for 4 aliphatic epoxides in mice

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    Sister-chromatid exchange (SCE) and chromosome aberrations (CA) in bone marrow cells were analyzed after in vivo exposure in mice to 4 aliphatic epoxides, namely 1-naphthyl glycidyl ether (NGE), 1-naphthyl propylene oxide (NPO), 4-nitrophenyl glycidyl ether (NPGE) and trichloropropylene oxide (TCPO). These compounds were selected as being among the most mutagenic aliphatic epoxides in our previous structure-mutagenicity studies with the Ames test. There were significant dose-related increases in SCE and CA results for all 4 epoxides. The order of genotoxicity as established through SCE was NGE > NPO > NPGE [congruent with] TCPO > solvent control. It is of interest that Ames Salmonella results are consistent with in vivo genotoxicity for these compounds. However, only the plate test version of the Ames procedure is consistent with this order of in vivo genotoxicity and neither preincubation Ames testing results nor chemical alkylation rates would have predicted this order.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27732/1/0000124.pd
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