1,378 research outputs found
Shelf Life of PMR Polyimide Monomer Solutions and Prepregs Extended
PMR (Polymerization of Monomeric Reactants) technology was developed in the mid-1970's at the NASA Glenn Research Center at Lewis Field for fabricating high-temperature stable polyimide composites. This technology allowed a solution of polyimide monomers or prepreg (a fiber, such as glass or graphite, impregnated with PMR polyimide monomers) to be thermally cured without the release of volatiles that cause the formation of voids unlike the non-PMR technology used for polyimide condensation type resins. The initial PMR resin introduced as PMR 15 is still commercially available and is used worldwide by aerospace industries as the state-of-the-art resin for high-temperature polyimide composite applications. PMR 15 offers easy composite processing, excellent composite mechanical property retention, a long lifetime at use temperatures of 500 to 550 F, and relatively low cost. Later, second-generation PMR resin versions, such as PMR II 50 and VCAP 75, offer improvements in the upper-use temperature (to 700 F) and in the useful life at temperature without major compromises in processing and property retention but with significant increases in resin cost. Newer versions of nontoxic (non-methylene dianiline) PMR resins, such as BAX PMR 15, offer similar advantages as originally found for PMR 15 but also with significant increases in resin cost. Thus, the current scope of the entire PMR technology available meets a wide range of aeronautical requirements for polymer composite applications
Human rights and public education
This article attempts a contrast to the contribution by Hugh Starkey. Rather than his account of the inexorable rise of human rights discourse, and of the implementation of human rights standards, human rights are here presented as always and necessarily scandalous and highly contested. First, I explain why the UK has lagged so far behind its European neighbours in implementing citizenship education. Second, a comparison with France shows that the latest UK reforms bring us up to 1789. Third, the twentieth-century second-generation social and economic rights are still anathema in the UK. Fourth, the failure to come to terms with Empire and especially the slave trade means that the UK’s attitude to third-generation rights, especially the right of peoples to self-determination, is heavily compromised. Taking into account the points I raise, citizenship education in the UK might look very different
Anti-Kaon Induced Reactions on the Nucleon
Using a previously established effective Lagrangian model we describe
anti-kaon induced reactions on the nucleon. The dominantly contributing
channels in the cm-energy region from threshold up to 1.72 GeV are included (K
N, \pi \Sigma, \pi \Lambda). We solve the Bethe-Salpeter equation in an unitary
-matrix approximation.Comment: 21 pages, 13 figures, minor typos corrected, accepted for publication
in Phys. Rev.
NuSTAR and Suzaku observations of the hard state in Cygnus X-1: locating the inner accretion disk
We present simultaneous Nuclear Spectroscopic Telescope Array (NuSTAR ) and
Suzaku observations of the X-ray binary Cygnus X-1 in the hard state. This is
the first time this state has been observed in Cyg X-1 with NuSTAR, which
enables us to study the reflection and broad-band spectra in unprecedented
detail. We confirm that the iron line cannot be fit with a combination of
narrow lines and absorption features, and instead requires a relativistically
blurred profile in combination with a narrow line and absorption from the
companion wind. We use the reflection models of Garcia et al. (2014) to
simultaneously measure the black hole spin, disk inner radius, and coronal
height in a self-consistent manner. Detailed fits to the iron line profile
indicate a high level of relativistic blurring, indicative of reflection from
the inner accretion disk. We find a high spin, a small inner disk radius, and a
low source height, and rule out truncation to greater than three gravitational
radii at the 3{\sigma} confidence level. In addition, we find that the line
profile has not changed greatly in the switch from soft to hard states, and
that the differences are consistent with changes in the underlying reflection
spectrum rather than the relativistic blurring. We find that the blurring
parameters are consistent when fitting either just the iron line or the entire
broad-band spectrum, which is well modelled with a Comptonized continuum plus
reflection model.Comment: 12 pages, 7 figures, accepted for publication in Ap
Agricultural R&D, technology and productivity.
Published versio
NuSTAR reveals the hidden nature of SS433
SS433 is the only Galactic binary system known to accrete at highly
super-critical rates, analogous to tidal disruption events, and needed to
explain the mass of some high redshift quasars. Probing the inner regions of
SS433 in the X-rays is crucial to understanding this system, and super-critical
accretion in general, but has not yet been possible due to obscuration. NuSTAR
observed SS433 in the hard X-ray band across multiple phases of its
super-orbital precession period. Spectral-timing tools have allowed us to
confirm that the hard X-ray emission from the inner regions is scattered
towards us by the walls of the wind-cone. By comparing to numerical models, we
determine an intrinsic X-ray luminosity of >= 3x10^37 erg/s and that, if viewed
face on, the apparent luminosity would be > 1x10^39 erg/s, confirming its
long-suspected nature as an ultraluminous X-ray source (ULX). A lag due to
absorption by Fe XXV/XXVI in outflowing material travelling at least 0.14-0.29c
matches absorption lines seen in ULXs and - in future - will allow us to map a
super-critical outflow for the first time.Comment: 24 pages, 8 figures, submitted for publicatio
Charge Transfer from Regularized Symmetry-Adapted Perturbation Theory
16 pages, 16 figure
Political brand image: an investigation into the operationalisation of the external orientation of David Cameron’s Conservative brand
This paper seeks to address the limited understanding of how to operationalise the external brand image of a political brand. More specifically, this research critically assesses the transfer potential of the six variables of brand image by Bosch, Venter, Han and Boshoff to deconstruct the UK Conservative Party brand from the perspective of young people aged 18–24 years during the 2010 UK General Election campaign. This research demonstrates the applicability of the six variables otherwise known as the ‘brand image framework’ to the political environment. However, the application of the brand image framework in its original conceptualisation proved problematic. Many of the brand image variables were clarified, rearticulated and simplified to address the political context. This refined conceptualisation provided an in-depth understanding of how to investigate the political brand image of David Cameron’s Conservative Party. This study addresses the paucity of research that operationalises external brand image and provides practitioners and academics within and beyond the context of political branding a mechanism to understand the external orientation of brands. This research may also be used by political and non-political brands as a basis to explore external brand image and compare its consistency with internal brand identity
- …