32,671 research outputs found
Application of inflated structures to hovercraft annual survey 1968-69: inflated structures report C1206/3
1.0 Introduction
This report surveys work carried out in the Department of Aircraft
Design at the College of Aeronautics, Cranfield, in accordance with the
terms of Ministry of Technology contract reference PD/28/045/ADM, College
of Aeronautics reference 0.1206. The period covered by this report
extends from 1st October 1968 to 1st October 1969, which constitutes
the first complete year of operation under the contract terms.
The reporting procedure agreed with Mintech is that individual research
topics shall be separately reported in the form of technical memoranda,
and that comprehensive surveys of a descriptive nature shall be submitted
at regular intervals
The measurement of biaxial strains in coated fabric materials using the disc-replica method
A method of measuring biaxial strains in coated fabric type materials
is presented whereby the strain is deduced from the distortion of a circular
impression made on the material. The impression is placed on the material
when loaded, enabling all measurements to be made with the material in its
relaxed, unloaded, state
The effect of parallel static and microwave electric fields on excited hydrogen atoms
Motivated by recent experiments we analyse the classical dynamics of a
hydrogen atom in parallel static and microwave electric fields. Using an
appropriate representation and averaging approximations we show that resonant
ionisation is controlled by a separatrix, and provide necessary conditions for
a dynamical resonance to affect the ionisation probability.
The position of the dynamical resonance is computed using a high-order
perturbation series, and estimate its radius of convergence. We show that the
position of the dynamical resonance does not coincide precisely with the
ionisation maxima, and that the field switch-on time can dramatically affect
the ionisation signal which, for long switch times, reflects the shape of an
incipient homoclinic. Similarly, the resonance ionisation time can reflect the
time-scale of the separatrix motion, which is therefore longer than
conventional static field Stark ionisation. We explain why these effects should
be observed in the quantum dynamics.
PACs: 32.80.Rm, 33.40.+f, 34.10.+x, 05.45.Ac, 05.45.MtComment: 47 pages, 20 figure
Polarization morphology of SiO masers in the circumstellar envelope of the AGB star R Cassiopeiae
Silicon monoxide maser emission has been detected in the circumstellar
envelopes of many evolved stars in various vibrationally-excited rotational
transitions. It is considered a good tracer of the wind dynamics close to the
photosphere of the star. We have investigated the polarization morphology in
the circumstellar envelope of an AGB star, R Cas. We mapped the linear and
circular polarization of SiO masers in the v=1, J=1-0 transition. The linear
polarization is typically a few tens of percent while the circular polarization
is a few percent. The fractional polarization tends to be higher for emission
of lower total intensity. We found that, in some isolated features the
fractional linear polarization appears to exceed 100%. We found the Faraday
rotation is not negligible but is ~15 deg., which could produce small scale
structure in polarized emission whilst total intensity is smoother and partly
resolved out. The polarization angles vary considerably from feature to feature
but there is a tendency to favour the directions parallel or perpendicular to
the radial direction with respect to the star. In some features, the
polarization angle abruptly flips 90 deg. We found that our data are in the
regime where the model of Goldreich et al (1973) can be applied and the
polarization angle flip is caused when the magnetic field is at close to 55
deg. to the line of sight. The polarization angle configuration is consistent
with a radial magnetic field although other configurations are not excluded.Comment: 14 pages, 15 figures. Accepted for publication in MNRA
On the edge of a new frontier: Is gerontological social work in the UK ready to meet twenty-first-century challenges?
This article is available open access through the publisher’s website. Copyright @ 2013 The Authors.This article explores the readiness of gerontological social work in the UK for meeting the challenges of an ageing society by investigating the focus on work with older people in social work education and the scope of gerontological social work research. The discussion draws on findings from two exploratory studies: a survey of qualifying master's programmes in England and a survey of the content relating to older people over a six-year period in four leading UK social work journals. The evidence from master's programmes suggests widespread neglect of ageing in teaching content and practice learning. Social work journals present a more nuanced picture. Older people emerge within coverage of generic policy issues for adults, such as personalisation and safeguarding, and there is good evidence of the complexity of need in late life. However, there is little attention to effective social work interventions, with an increasingly diverse older population, or to the quality of gerontological social work education. The case is made for infusing content on older people throughout the social work curriculum, for extending practice learning opportunities in social work with older people and for increasing the volume and reporting of gerontological social work research.Brunel Institute for Ageing Studie
Modelling fire-fighter responses to exercise and asymmetric infrared radiation using a dynamic multi-mode model of human physiology and results from the Sweating Agile thermal Manikin
Abstract : In this study, predicted dynamic physiological responses are compared with wear trials results for firefighter suits: impermeable (A), semi-permeable (B) and permeable (C), and underwear. Wear trials consisted of three rest phases and two moderate work phases, with a frontal infrared (IR) radiation exposure of 500W/m2 for the last 15min of each work phase. Simulations were performed by detailed modelling of the experimental boundary conditions, including the inhomogeneous IR radiation combined with clothing properties for still and walking conditions measured using the Sweating Agile thermal Manikin. Accounting for the effect of sweat gland activity suppression with increased skin wettedness, the predicted total moisture loss was insignificantly different (P<0.05) from the wear trial value for suits B and C but was 37% too high for suit A. Predicted evolution of core, mean skin and local skin temperatures agreed well with the wear trial results for all clothing. Root mean square deviations ranged from 0.11°C to 0.26°C for core temperatures and from 0.28°C to 0.38°C for mean skin temperatures, which where typically lower than the experimental error. Transient thermodynamic processes occurring within suit A may account for the delayed/reduced fall in core temperature following exercis
A multistage linear array assignment problem
The implementation of certain algorithms on parallel processing computing architectures can involve partitioning contiguous elements into a fixed number of groups, each of which is to be handled by a single processor. It is desired to find an assignment of elements to processors that minimizes the sum of the maximum workloads experienced at each stage. This problem can be viewed as a multi-objective network optimization problem. Polynomially-bounded algorithms are developed for the case of two stages, whereas the associated decision problem (for an arbitrary number of stages) is shown to be NP-complete. Heuristic procedures are therefore proposed and analyzed for the general problem. Computational experience with one of the exact problems, incorporating certain pruning rules, is presented with one of the exact problems. Empirical results also demonstrate that one of the heuristic procedures is especially effective in practice
Site-selective quantum correlations revealed by magnetic anisotropy in the tetramer system SeCuO3
We present the investigation of a monoclinic compound SeCuO3 using x-ray
powder diffraction, magnetization, torque and electron-spin-resonance (ESR).
Structurally based analysis suggests that SeCuO3 can be considered as a 3D
network of tetramers. The values of intra-tetramer exchange interactions are
extracted from the temperature dependence of the susceptibility and amount to
~200 K. The inter-tetramer coupling leads to the development of long-range
antiferromagnetic order at TN = 8 K. An unusual temperature dependence of the
effective g-tensors is observed, accompanied with a rotation of macroscopic
magnetic axes. We explain this unique observation as due to site-selective
quantum correlations
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