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Aspects of the Design of a Three-Dimensional National Mapping Data Framework
The role of forensic geoscience in wildlife crime detection
The increase in both automation and precision in the analysis of geological materials has had significant impact upon forensic investigations in the last 10 years. There is however, a fundamental philosophical difference between forensic and geological enquiry. This paper presents the results of forensic geoscientific investigations of three cases of wildlife crime. Two cases involve the analysis of soils recovered after incidents of illegal badger baiting in the United Kingdom. The third case involves the illegal importation of Eleonora's Falcon (Falco eleonorae) into the United Kingdom from the Mediterranean. All three cases utilise the analysis of soils by a variety of physical, chemical and biological techniques. These involve mineral and grain size analyses, cation and anion compositions, pH, organic content and pollen analysis.The independent analysis undertaken by specialists in each of these three main fields conclude firstly, that there is a significant similarity between sediments taken at the crime site at both badger setts and with sediments recovered from various spades, shovels and clothing belonging to suspects and secondly, that the soils analysed associated with the removal of the falcon eggs in the Mediterranean contained characteristics similar in many respects to the soils of the breeding areas of E eleonorae on the cliffs of Mallorca. The use of these independent techniques in wildlife crime detection has great potential given the ubiquitous nature of soils and sediments found in association with wildlife sites. (c) 2006 Elsevier Ireland Ltd. All rights reserved
Transparent polymeric laminates
Laminate prepared from epoxy-boroxine and phenolphthalein polycarbonate has high mechanical strength at elevated temperature and is resistant to impact, fire, and high-energy thermal radiation. Polycarbonate is prepared by reaction of phenolphthalein with phosgene in presence of amine catalyst and immiscible organic solvent phase
Turbulent magnetic dynamo excitation at low magnetic Prandtl number
Planetary and stellar dynamos likely result from turbulent motions in
magnetofluids with kinematic viscosities that are small compared to their
magnetic diffusivities. Laboratory experiments are in progress to produce
similar dynamos in liquid metals. This work reviews recent computations of
thresholds in critical magnetic Reynolds number above which dynamo
amplification can be expected for mechanically-forced turbulence (helical and
non-helical, short wavelength and long wavelength) as a function of the
magnetic Prandtl number . New results for helical forcing are discussed,
for which a dynamo is obtained at . The fact that the
kinetic turbulent spectrum is much broader in wavenumber space than the
magnetic spectrum leads to numerical difficulties which are bridged by a
combination of overlapping direct numerical simulations and subgrid models of
magnetohydrodynamic turbulence. Typically, the critical magnetic Reynolds
number increases steeply as the magnetic Prandtl number decreases, and then
reaches an asymptotic plateau at values of at most a few hundred. In the
turbulent regime and for magnetic Reynolds numbers large enough, both small and
large scale magnetic fields are excited. The interactions between different
scales in the flow are also discussed.Comment: 8 pages, 8 figures, to appear in Physics of Plasma
The Generation of Magnetic Fields Through Driven Turbulence
We have tested the ability of driven turbulence to generate magnetic field
structure from a weak uniform field using three dimensional numerical
simulations of incompressible turbulence. We used a pseudo-spectral code with a
numerical resolution of up to collocation points. We find that the
magnetic fields are amplified through field line stretching at a rate
proportional to the difference between the velocity and the magnetic field
strength times a constant. Equipartition between the kinetic and magnetic
energy densities occurs at a scale somewhat smaller than the kinetic energy
peak. Above the equipartition scale the velocity structure is, as expected,
nearly isotropic. The magnetic field structure at these scales is uncertain,
but the field correlation function is very weak. At the equipartition scale the
magnetic fields show only a moderate degree of anisotropy, so that the typical
radius of curvature of field lines is comparable to the typical perpendicular
scale for field reversal. In other words, there are few field reversals within
eddies at the equipartition scale, and no fine-grained series of reversals at
smaller scales. At scales below the equipartition scale, both velocity and
magnetic structures are anisotropic; the eddies are stretched along the local
magnetic field lines, and the magnetic energy dominates the kinetic energy on
the same scale by a factor which increases at higher wavenumbers. We do not
show a scale-free inertial range, but the power spectra are a function of
resolution and/or the imposed viscosity and resistivity. Our results are
consistent with the emergence of a scale-free inertial range at higher Reynolds
numbers.Comment: 14 pages (8 NEW figures), ApJ, in press (July 20, 2000?
Hawking radiation by Kerr black holes and conformal symmetry
The exponential blueshift associated with the event horizon of a black hole
makes conformal symmetry play a fundamental role in accounting for its thermal
properties. Using a derivation based on two-point functions, we show that the
spectrum of thermal radiation of scalar particles by Kerr (and Schwarzschild)
black holes can be explicitly derived on the basis of a -dimensional
conformal symmetry arising in the wave equation near the horizon. This result
reinforces the recently conjectured relation between Kerr geometry and a
-dimensional conformal field theory.Comment: Version published in Phys. Rev. Let
Carbonate Formation in Non-Aqueous Environments by Solid-Gas Carbonation of Silicates
We have produced synthetic analogues of cosmic silicates using the Sol Gel
method, producing amorphous silicates of composition Mg(x)Ca(1-x)SiO3. Using
synchrotron X-ray powder diffraction on Beamline I11 at the Diamond Light
Source, together with a newly-commissioned gas cell, real-time powder
diffraction scans have been taken of a range of silicates exposed to CO2 under
non-ambient conditions. The SXPD is complemented by other techniques including
Raman and Infrared Spectroscopy and SEM imaging.Comment: 5 pages, 3 figures. Contribution to the Proceedings of the First
European Conference on Laboratory Astrophysics (ECLA
Statistical Modeling of Epistasis and Linkage Decay using Logic Regression
Logic regression has been recognized as a tool that can identify and model non-additive genetic interactions using Boolean logic groups. Logic regression, TASSEL-GLM and SAS-GLM were compared for analytical precision using a previously characterized model system to identify the best genetic model explaining epistatic interaction for vernalization-sensitivity in barley. A genetic model containing two molecular markers identified in vernalization response in barley was selected using logic regression while both TASSEL-GLM and SAS-GLM included spurious associations in their models. The results also suggest the logic regression can be used to identify dominant/recessive relationships between epistatic alleles through its use of conjugate operators
Spatial curvature effects on molecular transport by diffusion
For a substance diffusing on a curved surface, we obtain an explicit relation
valid for very small values of the time, between the local concentration, the
diffusion coefficient, the intrinsic spatial curvature and the time. We recover
the known solution of Fick's law of diffusion in the flat space limit. In the
biological context, this result would be useful in understanding the variations
in the diffusion rates of integral proteins and other molecules on membranes.Comment: 10 page
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