27,691 research outputs found
An Integrative Analysis of Business Bankruptcy in Australia.
This paper proposes an integrative and dynamic approach for analyzing business failure. The simulaneous estimation results obtained with Australian data indicate significant associations between bankruptcy rates in different industries. Most of these associations are positive and hence implying that bankruptcy in one industry can inflict a "domino" effect on other industries.BANKRUPTCY
Molecular dynamics study of nanoparticle stability at liquid interfaces : effect of nanoparticle-solvent interaction and capillary waves
While the interaction of colloidal particles (sizes in excess of 100 nm) with liquid interfaces may be understood in terms of continuum models, which are grounded in macroscopic properties such as surface and line tensions, the behaviour of nanoparticles at liquid interfaces may be more complex. Recent simulations [D. L. Cheung and S. A. F. Bon, Phys. Rev. Lett. 102, 066103 (2009)] of nanoparticles at an idealised liquid-liquid interface showed that the nanoparticle-interface interaction range was larger than expected due, in part, to the action of thermal capillary waves. In this paper, molecular dynamics simulations of a Lennard-Jones nanoparticle in a binary Lennard-Jones mixture are used to confirm that these previous results hold for more realistic models. Furthermore by including attractive interactions between the nanoparticle and the solvent, it is found that the detachment energy decreases as the nanoparticle-solvent attraction increases. Comparison between the simulation results and recent theoretical predictions [H. Lehle and M. Oettel, J. Phys. Condens. Matter 20, 404224 (2008)] shows that for small particles the incorporation of capillary waves into the predicted effective nanoparticle-interface interaction improves agreement between simulation and theory
Application of CFD to sonic boom near and mid flow-field prediction
A 3-D parabolized Navier-Stokes (PNS) code was used to calculate the supersonic overpressures from three different geometries at near- and mid-flow fields. Wind tunnel data is used for code validation. Comparison of the computed results with different grid refinements is shown. It is observed that a large number of grid points is needed to resolve the tail shock/expansion fan interaction. Therefore, an adaptive grid approach is employed to calculate the flow field. The agreement between the numerical results and the wind tunnel data confirms that computational fluid dynamics can be applied to the problem of sonic boom prediction
Laser surface colouring of titanium for contemporary jewellery
This paper describes work which emerged through a need to understand more about the potential of laser surface engineering for use in the creative industries. The method of creation of contemporary jewellery pieces and the resultant 'Ocular' jewellery series are described from the creative point of view. The work demonstrates how laser controlled oxide growth on Ti–6Al–4V alloy under ambient conditions can be used as an artistic tool by producing precisely defined colours. Use of the method to produce regular areas of even colour and to reproduce freehand drawings on a titanium alloy surface is described. Analysis highlights interference as the main colouring mechanism and suggests a graded surface layer, progressing from an outer layer of TiO2 to lower layers rich in TiO and Ti2O. The model of research by practice presented in this paper offers a contribution to the current debate on partnerships between art and science and engineering
Paraoxonase gene polymorphisms and haplotype analysis in a stroke population
Peer reviewedPublisher PD
1.0 Mm Maps and Radial Density Distributions of Southern Hii/molecular Cloud Complexes
Several 1.0 continuum mapping observations were made of seven southern hemisphere h12/molecular cloud complexes with 65 arcsec resolution. The radial density distribution of the clouds with central luminosity sources was determined observationally. Strong similarities in morphology and general physical conditions were found to exist among all of the southern clouds in the sample
The consistency condition for the three-point function in dissipative single-clock inflation
We generalize the consistency condition for the three-point function in
single field inflation to the case of dissipative, multi-field, single-clock
models. We use the recently introduced extension of the effective field theory
of inflation that accounts for dissipative effects, to provide an explicit
proof to leading (non-trivial) order in the generalized slow roll parameters
and mixing with gravity scales. Our results illustrate the conditions necessary
for the validity of the consistency relation in situations with many degrees of
freedom relevant during inflation, namely that there is a preferred clock.
Departures from this condition in forthcoming experiments would rule out not
only single field but also a large class of multi-field models.Comment: 26+11 page
X-ray Emitting GHz-Peaked Spectrum Galaxies: Testing a Dynamical-Radiative Model with Broad-Band Spectra
In a dynamical-radiative model we recently developed to describe the physics
of compact, GHz-Peaked-Spectrum (GPS) sources, the relativistic jets propagate
across the inner, kpc-sized region of the host galaxy, while the electron
population of the expanding lobes evolves and emits synchrotron and
inverse-Compton (IC) radiation. Interstellar-medium gas clouds engulfed by the
expanding lobes, and photoionized by the active nucleus, are responsible for
the radio spectral turnover through free-free absorption (FFA) of the
synchrotron photons. The model provides a description of the evolution of the
spectral energy distribution (SED) of GPS sources with their expansion,
predicting significant and complex high-energy emission, from the X-ray to the
gamma-ray frequency domain. Here, we test this model with the broad-band SEDs
of a sample of eleven X-ray emitting GPS galaxies with Compact-Symmetric-Object
(CSO) morphology, and show that: (i) the shape of the radio continuum at
frequencies lower than the spectral turnover is indeed well accounted for by
the FFA mechanism; (ii) the observed X-ray spectra can be interpreted as
non-thermal radiation produced via IC scattering of the local radiation fields
off the lobe particles, providing a viable alternative to the thermal,
accretion-disk dominated scenario. We also show that the relation between the
hydrogen column densities derived from the X-ray (N_H) and radio (N_HI) data of
the sources is suggestive of a positive correlation, which, if confirmed by
future observations, would provide further support to our scenario of
high-energy emitting lobes.Comment: 29 pages, 3 figures, 6 tables; to appear in ApJ. A few clarifications
included, according to referee's suggestion
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