37,074 research outputs found

    Fabric for micrometeoroid protection garment Patent

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    Structure of fabric layers for micrometeoroid protection garment with capability for eliminating heat shorts for use in manufacturing space suit

    Orbital stability in combined uniform axial and three-dimensional wiggler magnetic fields for free-electron lasers

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    Zachary Phys. Rev. A 29 (6), 3224 (1984) recently analyzed the instability of relativistic-electron helical trajectories in combined uniform axial and helical wiggler magnetic fields when the radial variation of the wiggler field is taken into account. It is shown here that the type 2 instability comprised of secular terms growing linearly in time, identified by Zachary and earlier by Diament Phys. Rev. A 23 (5), 2537 (1981), is an artifact of simple perturbation theory. A multiple-time-scale perturbation analysis reveals a nonsecular evolution on a slower time scale which accommodates an arbitrary initial perturbation. It is shown that, in the absence of exponential instability, the electron seeks a modified helical orbit more appropriate to its perturbed state and oscillates stably about it. Thus, the perturbed motion is oscillatory but nonsecular, and hence the helical orbits are stable

    Changing clinical behaviour by making guidelines specific

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    Efforts to get doctors to follow guidelines have overlooked the importance of clear and concise recommendation

    Neutron interference scattering in crystalline solids Progress report

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    Neutron elastic and inelastic interference scattering cross section in crystalline lattices of solid

    Tailed Radio Galaxies as Probes of Cluster Physics in the Square Kilometre Array Era

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    In recent years, the use of tailed radio galaxies as environmental probes has gained momentum as a method for galaxy cluster detection, examining the dynamics of individual clusters, measuring the density and velocity flows in the intra-cluster medium, and for probing cluster magnetic fields. To date instrumental limitations in terms of resolution and sensitivity have confined this research to the local (z < 0.7) Universe. The advent of SKA-1 surveys however will allow detection of well over 1 million tailed radio galaxies and their associated galaxy clusters out to redshifts of 2 or more. This is in fact ten times more than the current number of known clusters in the Universe. Such a substantial sample of tailed galaxies will provide an invaluable tool not only for detecting clusters, but also for characterizing their intra-cluster medium, magnetic fields and dynamical state as a function of cosmic time. In this paper we present an analysis of the usability of tailed radio galaxies as tracers of dense environments extrapolated from existing deep radio surveys such the Extended Chandra Deep Field-South.Comment: 4 pages, 2 figures, in URSI GASS (XXXIth) held 16-23 August 2014, Beijing, China. Published as AIP Conference Proceeding

    Constraints on viewing geometries from radio observations of ╬│\gamma-ray-loud pulsars using a novel method

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    We present radio intensity and polarisation profiles of 28 ╬│\gamma-ray-detected pulsars with the aim of putting constraints on their viewing geometries using data from the Parkes telescope. Constraints are formed both from the goodness-of-fit of the position angles to the Rotating Vector Model and from the beam opening angle considering aberration and retardation effects. Uncertainties on the relevant parameters are systematically taken into account in order to produce a more robust constraint, using a new approach. Surprisingly, we find that the distribution of the magnetic inclination angle (╬▒\alpha) in this subset of pulsars peaks at low values, contrary to the predictions of ╬│\gamma-ray models. We find a lack of correlation between these and a set of ╬▒\alpha values which were derived using ╬│\gamma-ray light curves, suggesting a problem in the interpretation of the data in one or both of these domains. Finally, we also show that the ╬▒\alpha distribution of pulsars with multiple radio components is no different to that of single-component pulsars.Comment: 23 pages, 31 figures Submitted to MNRA
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