The Development of explosives competencies, training and education in the UK

Competent explosives workers in the Armed Forces and in the civil sector are critical to the safe production, testing and use of explosives. Moreover we need competent explosives specialists to combat the challenge from terrorism and clean up the planet from the explosive hazards that are the legacy of past conflicts. Unfortunately many countries are witnessing a significant loss of capability in this area and are looking at ways of replenishing vital expertise. This paper describes the work done in recent years by the authors and others in the UK to establish numbers of people working in the sector and to consider the skills and knowledge required to carry out their work. It outlines the concept of national occupational standards and the framework of professional and vocational qualifications that are available or are being developed for explosives specialists. It also describes some of the educational and e-learning programmes designed to support this initiative. Ultimately the aim is to address the professionalism of all personnel who deal with explosives in order to reduce the incidence and consequence of accidents and maintain national capability

The Nearshore Fish Fauna of Bonne Bay, a Fjord within Gros Morne National Park, Newfoundland

A standardized survey of the nearshore fish fauna of Bonne Bay, a fjord within Gros Morne National Park in western Newfoundland, was conducted using beach seines, gill-nets and bottom trawls during the month of June over a seven year period (2002- 2008). The survey documents the presence of 31 fish species (in 17 taxonomic families). Sampling sites varied in benthic habitat and associated fish assemblages. Both juvenile and adult life history stages of Atlantic cod (Gadus morhua) were present in Bonne Bay, suggesting the presence of a local population or “bay cod stock”. Acadian redfish (Sebastes fasciatus) live in the bay, and may be members of a genetically differentiable population of redfish. Striped wolfish (Anarhichas lupus), a fish species protected under Canada’s Species at Risk Act (SARA), inhabits Bonne Bay. Surrounded by Gros Morne National Park, this bay with a diverse fish fauna is a focus of local stewardship and conservation efforts

Recurrence in generic staircases

The straight-line flow on almost every staircase and on almost every square tiled staircase is recurrent. For almost every square tiled staircase the set of periodic orbits is dense in the phase space

Searching for Dark Matter with Future Cosmic Positron Experiments

Dark matter particles annihilating in the Galactic halo can provide a flux of positrons potentially observable in upcoming experiments, such as PAMELA and AMS-02. We discuss the spectral features which may be associated with dark matter annihilation in the positron spectrum and assess the prospects for observing such features in future experiments. Although we focus on some specific dark matter candidates, neutralinos and Kaluza-Klein states, we carry out our study in a model independent fashion. We also revisit the positron spectrum observed by HEAT.Comment: 19 pages, 33 figure

Kaluza-Klein Dark Matter, Electrons and Gamma Ray Telescopes

Kaluza-Klein dark matter particles can annihilate efficiently into electron-positron pairs, providing a discrete feature (a sharp edge) in the cosmic $e^+ e^-$ spectrum at an energy equal to the particle's mass (typically several hundred GeV to one TeV). Although this feature is probably beyond the reach of satellite or balloon-based cosmic ray experiments (those that distinguish the charge and mass of the primary particle), gamma ray telescopes may provide an alternative detection method. Designed to observe very high-energy gamma-rays, ACTs also observe the diffuse flux of electron-induced electromagnetic showers. The GLAST satellite, designed for gamma ray astronomy, will also observe any high energy showers (several hundred GeV and above) in its calorimeter. We show that high-significance detections of an electron-positron feature from Kaluza-Klein dark matter annihilations are possible with GLAST, and also with ACTs such as HESS, VERITAS or MAGIC.Comment: 10 pages, 2 figure

Predictions for the Cosmogenic Neutrino Flux in Light of New Data from the Pierre Auger Observatory

The Pierre Auger Observatory (PAO) has measured the spectrum and composition of the ultrahigh energy cosmic rays with unprecedented precision. We use these measurements to constrain their spectrum and composition as injected from their sources and, in turn, use these results to estimate the spectrum of cosmogenic neutrinos generated in their propagation through intergalactic space. We find that the PAO measurements can be well fit if the injected cosmic rays consist entirely of nuclei with masses in the intermediate (C, N, O) to heavy (Fe, Si) range. A mixture of protons and heavier species is also acceptable but (on the basis of existing hadronic interaction models) injection of pure light nuclei (p, He) results in unacceptable fits to the new elongation rate data. The expected spectrum of cosmogenic neutrinos can vary considerably, depending on the precise spectrum and chemical composition injected from the cosmic ray sources. In the models where heavy nuclei dominate the cosmic ray spectrum and few dissociated protons exceed GZK energies, the cosmogenic neutrino flux can be suppressed by up to two orders of magnitude relative to the all-proton prediction, making its detection beyond the reach of current and planned neutrino telescopes. Other models consistent with the data, however, are proton-dominated with only a small (1-10%) admixture of heavy nuclei and predict an associated cosmogenic flux within the reach of upcoming experiments. Thus a detection or non-detection of cosmogenic neutrinos can assist in discriminating between these possibilities.Comment: 10 pages, 7 figure

Decay of High-Energy Astrophysical Neutrinos

Existing limits on the non-radiative decay of one neutrino to another plus a massless particle (e.g., a singlet Majoron) are very weak. The best limits on the lifetime to mass ratio come from solar neutrino observations, and are \tau/m \agt 10^{-4} s/eV for the relevant mass eigenstate(s). For lifetimes even several orders of magnitude longer, high-energy neutrinos from distant astrophysical sources would decay. This would strongly alter the flavor ratios from the $\phi_{\nu_e}:\phi_{\nu_{\mu}}:\phi_{\nu_{\tau}} = 1:1:1$ expected from oscillations alone, and should be readily visible in the near future in detectors such as IceCube.Comment: 4 pages, 1 figure. References added. Version to appear in PR

Wind-profiler observations of gravity waves produced by convection at mid-latitudes

This work presents a case study which includes regions of large rapidly varying vertical velocities observed by a VHF wind-profiler at Aberystwyth (52.4° N, 4.1° W). Analysis indicates that this region is associated with gravity waves above the tropopause level and simultaneous regions of convective activity below the tropopause level. This case study also suggests that convective activity can be identified effectively by finding periods of large uncertainties on the derived velocities. These regions are hypothesized to be related to regions of small-scale inhomogeneity in the wind field. Examination suggests that the large vertical velocity fluctuations above these convective regions are short period gravity wave packets as expected from theory. In addition the vertical flux of the horizontal momentum associated with the gravity waves also displays the pattern of reversal observed in previous studies