Insurance for autonomous underwater vehicles

The background and practice of insurance for autonomous underwater vehicles (AUVs) are examined. Key topics include: relationships between clients, brokers and underwriters; contract wording to provide appropriate coverage; and actions to take when an incident occurs. Factors that affect cost of insurance are discussed, including level of autonomy, team experience and operating environment. Four case studies from industry and academia illustrate how AUV insurance has worked in practice. The paper concludes by stressing the importance of effective dialogue between client, broker and underwriter to review, assess and reduce risk to the benefit of all parties

Hydrogen bonding in C-methylated nitroanilines : the three-dimensional framework structure of 2-methyl-4-nitroaniline

Peer reviewedPublisher PD

The Spectacular Ionized Interstellar Medium of NGC55

We present deep Halpha+[NII], [SII] (6716,6731A) and [OII] (3726,3729A) images of the highly inclined, actively star--forming SBm galaxy NGC 55, located in the nearby Sculptor Group. Due to its proximity, NGC 55 provides a unique opportunity to study the disk--halo interface in a late--type galaxy with unprecedented spatial resolution. Our images reveal a spectacular variety of ionized gas features, ranging from giant HII region complexes, to supergiant filamentary and shell features, to patches of very faint diffuse emission. Many of these features protrude well above the plane of the galaxy, including a very faint fragmented shell of emission which is visible at 2.6 kpc above the disk. We identify candidate `chimneys' extending out of the disk, which could be the conduits into the halo for hot gas around disk star-forming regions, and could also provide low-density paths for the passage of UV photons from the disk to the halo. Several of the identified chimneys are `capped' with clumps of ionized gas, one of which, located at 1.5 kpc above the disk plane, appears to be the site of recent star formation. Emission--line ratios ([OII]/Halpha+[NII], [SII]/Halpha+[NII]) constrain the ionization mechanism of the gas, and our images allow the first measurement of [OII]/Halpha+[NII] in extra-planar diffuse ionized gas. The diffuse gas is characterized by emission--line ratios which are enhanced on average by a factor of two compared to those of bright HII regions. Each line ratio increases in value smoothly from the cores of HII regions, through the haloes of HII regions, into the diffuse ionized gas. Such a continuous trend is predicted by models in which the diffuse gas is ionized by photons produced by massive stars in HII regions.Comment: 19 pages, including 4 figures, plus 2 external tables. Accepted for publication in the Astronomical Journal. Compressed, postscript versions of the plates are available at ftp://skysrv.pha.jhu.edu/ferguson

A quantitative study of quasiparticle traps using the single-Cooper-pair-transistor

We use radio-frequency reflectometry to measure quasiparticle tunneling rates in the single-Cooper-pair-transistor. Devices with and without quasiparticle traps in proximity to the island are studied. A $10^2$ to $10^3$-fold reduction in the quasiparticle tunneling rate onto the island is observed in the case of quasiparticle traps. In the quasiparticle trap samples we also measure a commensurate decrease in quasiparticle tunneling rate off the island.Comment: 4 pages, 4 fig