Comparison of terahertz technologies for detection and identification of explosives

We present results on the comparison of different THz technologies for the detection and identification of a variety of explosives from our laboratory tests that were carried out in the framework of NATO SET-193 THz technology for stand-off detection of explosives: from laboratory spectroscopy to detection in the field under the same controlled conditions. Several laser-pumped pulsed broadband THz time-domain spectroscopy (TDS) systems as well as one electronic frequency-modulated continuous wave (FMCW) device recorded THz spectra in transmission and/or reflection. © 2014 SPIE

Associations of autozygosity with a broad range of human phenotypes

In many species, the offspring of related parents suffer reduced reproductive success, a phenomenon known as inbreeding depression. In humans, the importance of this effect has remained unclear, partly because reproduction between close relatives is both rare and frequently associated with confounding social factors. Here, using genomic inbreeding coefficients (F-ROH) for >1.4 million individuals, we show that F-ROH is significantly associated (p <0.0005) with apparently deleterious changes in 32 out of 100 traits analysed. These changes are associated with runs of homozygosity (ROH), but not with common variant homozygosity, suggesting that genetic variants associated with inbreeding depression are predominantly rare. The effect on fertility is striking: F-ROH equivalent to the offspring of first cousins is associated with a 55% decrease [95% CI 44-66%] in the odds of having children. Finally, the effects of F-ROH are confirmed within full-sibling pairs, where the variation in F-ROH is independent of all environmental confounding.Peer reviewe

On low-frequency noise of polycrystalline GexSi1-x for sub-micron CMOS technologies

Polycrystalline gate films of GexSi1?x were deposited using low pressure chemical vapor deposition. To study the effects of different Ge contents on the noise properties, a value x=0, 0.3, and 0.6 was selected. Samples of 300 and 500 nm thickness were prepared for comparing the thickness effects on the quality of the gate films. The gate films were implanted with different concentrations of boron. The morphology and electrical properties have been characterized using atomic force microscopy, transmission electron microscopy, and Hall-effect measurements. Conductance fluctuations were measured at room temperature. We present here how low-frequency noise depends on the Ge contents, the doping concentration, and on the thickness of the gate film. The 1/f noise in polycrystalline GexSi1?x can be analyzed in terms of mobility fluctuations caused by lattice scattering

ACCELERATION 1/F NOISE IN SILICON MOSFETs

It is usually assumed that the 1/f noise in Si-MOSFETs is limited by collision 1/f noise. We found this to be the case for devices with relatively short channel lengths (L<10µm) but for channels of intermediate length (10µm<L<194µm) we found that the Hooge parameter varies as L2. We attributed this to acceleration of the electrons by the applied field, accompanied by Bremsstrahlung emission and current 1/f noise generation. This is a new noise source

Observations on military exploitation of explosives detection technologies

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