843 research outputs found
Compression properties of polymeric syntactic foam composites under cyclic loading
Syntactic foams are composite materials frequently used in applications
requiring the properties of low density and high damage tolerance. In the
present work, polymer-based syntactic foams were studied under cyclic
compression in order to investigate their compressibility, recoverability,
energy dissipation and damage tolerance. These syntactic foams were
manufactured by adding hollow polymer microspheres of various sizes and wall
thicknesses into a polyurethane matrix. The associated loading and unloading
curves during cyclic testing were recorded, revealing the viscoelastic nature
of the materials. SEM images of the samples were obtained in order to study
potential damage mechanisms during compression. It was observed that these
syntactic foams exhibit high elastic recovery and energy dissipation over a
wide range of compressional strains and the addition of polymer microspheres
mitigate the damage under compressional loading.Comment: 25 pages, 13 figure
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Improving the well-being of older people by reducing their energy consumption through energy-aware systems
Abstract-Fuel poverty is becoming a problem amongst the older community in the UK. We propose an assistive technology for reduced energy consumption in aid of active aging. We introduce how the well-being of older people within the community can be improved by reducing anxiety associated with fuel poverty. A recommender and behavioural change system will be introduced, which enables older people to improve their energy footprint through energy-aware systems. Using systems to help reduce fuel poverty will invariably improve their general well-being. Results show how this technology can be accepted and act as an enabler in improving the overall well-being of older people
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'A Reputation to Protect':Sport-team reputation as a strategic source of brand equity
This study investigates how sports-team reputation shapes brand equity through consumers’ relationship satisfaction, life satisfaction, and commitment. Data were collected from India in two stages, with 523 responses used to test relationships among constructs via structural equation modelling. Barring the effects of social responsibility and financial soundness on relationship satisfaction and the effect of life satisfaction on team brand equity, all hypothesised relationships were significant. Self-congruity also positively moderated relationship satisfaction outcomes, including sport-team heritage, spectator orientation, and management style dimensions. The study's findings provide important insights for managers, highlighting the crucial role of a strong reputation in building consumer team loyalty. Our research suggests that marketing strategies should focus on enhancing consumer self-identification by involving fans in on-field and off-field successes to foster meaningful connections
DOMestic Energy Systems and Technologies InCubator (DOMESTIC) and indoor air quality of the built environment
Oral presentation at RMetS Students and Early Career Scientists Conference 2020 on research project DOMESTIC (DOMestic Energy Systems and Technologies InCubator), which aims to build a facility for the demonstration of domestic technologies and design methodologies (i.e. air quality, energy efficiency)
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Energy-aware systems for improving the well-being of older people by reducing their energy consumption
Fuel poverty is becoming a problem amongst the older community in the UK. To help reduce the anxiety that fuel poverty places on older members of the community, this paper will first address why such systems are necessary before introducing a system and various interfaces for engaging and promoting better energy usage. Key areas of the proposed prototype will be discussed which focuses on a recommender and behavioural change system which enables older people to improve their energy footprint through energy-aware systems. Using systems to help reduce fuel poverty will invariably improve their general well-being. Results show how this technology can be accepted and act as an enabler in improving the overall well-being of older people as well as other system considerations. In addition, a number of subsequent phases of the project will be detailed which will discuss a longer test duration, an analysis of the data harvested and future directions
Accurate <i>ab initio</i> ro-vibronic spectroscopy of the X<sup>2</sup>∏ CCN radical using explicitly correlated methods
Explicitly correlated CCSD(T)-F12b calculations have been carried out with systematic sequences of correlation consistent basis sets to determine accurate near-equilibrium potential energy surfaces for the X<sup>2</sup>∏ and a<sup>4</sup>Σ<sup>−</sup> electronic states of the CCN radical. After including contributions due to core correlation, scalar relativity, and higher order electron correlation effects, the latter utilizing large-scale multireference configuration interaction calculations, the resulting surfaces were employed in variational calculations of the ro-vibronic spectra. These calculations also included the use of accurate spin-orbit and dipole moment matrix elements. The resulting ro-vibronic transition energies, including the Renner-Teller sub-bands involving the bending mode, agree with the available experimental data to within 3 cm<sup>−1</sup> in all cases. Full sets of spectroscopic constants are reported using the usual second-order perturbation theory expressions. Integrated absorption intensities are given for a number of selected vibronic band origins. A computational procedure similar to that used in the determination of the potential energy functions was also utilized to predict the formation enthalpy of CCN, ΔH<sub>f</sub>(0K) = 161.7 ± 0.5 kcal/mol
Chandra X-ray Observatory Arcsecond Imaging of the Young, Oxygen-rich Supernova Remnant 1E0102.2-7219
We present observations of the young, Oxygen-rich supernova remnant
1E0102.2-7219 taken by the Chandra X-ray Observatory during Chandra's Orbital
Activation and Checkout phase. The boundary of the blast wave shock is clearly
seen for the first time, allowing the diameter of the remnant and the mean
blast wave velocity to be determined accurately. The prominent X-ray bright
ring of material may be the result of the reverse shock encountering ejecta;
the radial variation of O VII vs. O VIII emission indicates an ionizing shock
propagating inwards, possibly through a strong density gradient in the ejecta.
We compare the X-ray emission to Australia Telescope Compact Array 6 cm radio
observations (Amy and Ball) and to archival Hubble Space Telescope [O III]
observations. The ring of radio emission is predominantly inward of the outer
blast wave, consistent with an interpretation as synchrotron radiation
originating behind the blast wave, but outward of the bright X-ray ring of
emission. Many (but not all) of the prominent optical filaments are seen to
correspond to X-ray bright regions. We obtain an upper limit of ~9e33 erg/s (3
sigma) on any potential pulsar X-ray emission from the central region.Comment: Accepted for pulication in Ap. J. Letters. 4 pages, 6 figures (one
color figure). Formatted with emulateapj5. Revised to incorporate copyediting
changes. High-resolution postscript (3.02MB) and tiff versions of the color
figure are available from
http://chandra.harvard.edu/photo/cycle1/0015multi/index.htm
Deeper Chandra Follow-up of Cygnus TeV Source Perpetuates Mystery
A 50 ksec Chandra observation of the unidentified TeV source in Cygnus
reported by the HEGRA collaboration reveals no obvious diffuse X-ray
counterpart. However, 240 Pointlike X-ray sources are detected within or nearby
the extended TeV J2032+4130 source region, of which at least 36 are massive
stars and 2 may be radio emitters. That the HEGRA source is a composite, having
as counterpart the multiple point-like X-ray sources we observe, cannot be
ruled out. Indeed, the distribution of point-like X-ray sources appears
non-uniform and concentrated broadly within the extent of the TeV source
region. We offer a hypothesis for the origin of the very high energy gamma-ray
emission in Cyg OB2 based on the local acceleration of TeV range cosmic rays
and the differential distribution of OB vs. less massive stars in this
association.Comment: Substantially revised version; incorporates referee suggestions &
expanded discussio
Jet-Induced Nucleosynthesis in Misaligned Microquasars
The jet axes and the orbital planes of microquasar systems are usually
assumed to be approximately perpendicular, eventhough this is not currently an
observational requirement. On the contrary, in one of the few systems where the
relative orientations are well-constrained, V4641Sgr, the jet axis is known to
lie not more than ~36 degrees from the binary plane. Such a jet, lying close to
the binary plane, and traveling at a significant fraction of the speed of light
may periodically impact the secondary star initiating nuclear reactions on its
surface. The integrated yield of such nuclear reactions over the age of the
binary system (less the radiative mass loss) will detectably alter the
elemental abundances of the companion star. This scenario may explain the
anomalously high Li enhancements (roughly ~20-200 times the sun's photospheric
value; or, equivalently, 0.1-1 times the average solar system value) seen in
the companions of some black-hole X-ray binary systems. (Such enhancements are
puzzling since Li nuclei are exceedingly fragile - being easily destroyed in
the interiors of stars - and Li would be expected to be depleted rather than
enhanced there.) Gamma-ray line signatures of the proposed process could
include the 2.22 MeV neutron capture line as well as the 0.478 MeV 7Li*
de-excitation line, both of which may be discernable with the INTEGRAL
satellite if produced in an optically thin region during a large outburst. For
very energetic jets, a relatively narrow neutral pion gamma-decay signature at
67.5 MeV could also be measurable with the GLAST satellite. We argue that about
10-20% of all microquasar systems ought to be sufficiently misaligned as to be
undergoing the proposed jet-secondary impacts.Comment: ApJ, accepted. Includes referee's suggestions and some minor
clarifications over previous versio
Studies on wound healing activity of some Euphorbia species on experimental rats
Background: Plants of Euphorbiaceae are used in folkloric medicines in variety of ailments and well known for chemical diversity of their isoprenoid constituents. This study was carried out to explore the preliminary wound healing potential of four Euphorbia species (E. consorbina 1, E. consorbina 2, E. inarticulata, E. balsamifera and E. schimperi).Materials and Methods: Excision wound surface of the animals were topically treated with ethyl acetate and methanol extracts of plants at a dose of 400 mg/kg body weight for twenty days. Povidone-iodine ointment was used as a reference drug. Wound contraction measurement and period of epithelialization were used to assess the effect of plants extracts on wound repairing.Results: The groups treated with methanol extracts of E. balsamifera and E. schimperi showed profound effects, high rate of wound contraction (100%) and decrease in epithelization period 19.00±0.40 and 18.50±0.64 respectively, followed by methanol extracts of E. consorbina 2, ethyl acetate extract of E. inarticulata and ethyl acetate extracts of E. consorbina 2 which showed significant (P <0.001) wound contraction and decrease in epithelization period. Conversely ethyl acetate extract of E. consorbina 1, E. balsamifera and E. schimperi and methanol extract of E. Consorbina 1 and E. Inarticulata treated groups was not showing significant wound healing. Methanol extracts of E. balsamifera and E. schimperi were also tested for their safety margin and found safe up to dose of 2000mg/kg body weight.Conclusion: Topical application of methanol extracts of E. balsamifera and E. schimperi have potential wound healing activity which is identical with standard drug Povidone-iodine.Keywords: Wound healing, excision wounds, Euphorbia, extract
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