28 research outputs found
Presence of Priority Polycyclic Aromatic Hydrocarbons, Chromium, Copper and Lead in Two selected Brownfield Sites in United Kingdom
In recent years, concerns about adverse effects of increasing land contamination paralleled with the increasing demand for land has emphasized need for sustainable remediation strategies. Soil samples were collected from two brownfield sites, in Saltley, Birmingham and Swansea, South Wales, United Kingdom and analysed to establish the extent of contamination by priority polycyclic aromatic hydrocarbon (PAH) compounds. Saltley site had a total PAH concentration of 41.0 mg kg-1 with high concentrations of phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene, chrysene and benzo[a]pyrene, total benzo[a]pyrene equivalent value of 6.0 mg kg-1 and total carcinogenic PAH of 19.0 mg kg-1. At the Swansea site, total PAH concentration ranged from 5.0 â 85.0 mg kg-1 with pyrene, fluoranthene, benzo[a]anthracene, chrysene, benzo[a]pyrene as the predominant PAHs, total benzo[a]pyrene equivalent value of 0.9 â 2.0 mg kg-1 and total carcinogenic PAH concentration of 2.6 â 11.0 mg kg-1. Heavy metal concentrations were above the ambient background concentrations for urban/industrial area. Both brownfield sites had a mixture of PAH and heavy metal contamination in varying concentrations with implication for the selection of efficient remedial strategies to enable their redevelopment
Photoproduction of the Lambda(1405) on the proton and nuclei
We study the gamma p ---> K^+ Lambda(1405) reaction at energies close to
threshold using a chiral unitary model where the resonance is generated
dynamically from K^-p interaction with other channels constructed from the
octets of baryons and mesons. Predictions are made for cross sections into
several channels and it is shown that the detection of the K^+ is sufficient to
determine the shape and strength of the Lambda(1405) resonance. The
determination of the resonance properties in nuclei requires instead the
detection of the resonance decay channels. Pauli blocking effects on the
resonance, which have been shown to be very important for the resonance at rest
in the nucleus, are irrelevant here where the resonance is produced with a
large momentum. The nuclear modifications here would thus offer information on
the resonance and K^- nucleus dynamics complementary to the one offered so far
by K^- atoms.Comment: 9 pages, 4 postscripts figure
White-faced Darter distribution is associated with coniferous forests in Great Britain
Abstract
1) Understanding of dragonfly distributions is often geographically comprehensive but less so in ecological terms.
2) White-faced darter (Leucorhinnia dubia) is a lowland peatbog specialist dragonfly which has experienced population declines in Great Britain. White-faced darter are thought to rely on peat-rich pool complexes within woodland but this has not yet been empirically tested.
3) We used dragonfly recording data collected by volunteers of the British Dragonfly Society from 2005 to 2018 to model habitat preference for white-faced darter using species distribution models across Great Britain and, with a more detailed landcover dataset, specifically in the North of Scotland.
4) Across the whole of Great Britain our models used the proportion of coniferous forest within 1km as the most important predictor of habitat suitability but were not able to predict all current populations in England.
5) In the North of Scotland our models were more successful and suggest that habitats characterised by native coniferous forest and areas high potential evapotranspiration represent the most suitable habitat for white-faced darter.
6) We recommend that future white-faced darter monitoring should be expanded to include areas currently poorly surveyed but with high suitability in the North of Scotland.
7) Our results also suggest that white-faced darter management should concentrate on maintaining Sphagnum rich pool complexes and the maintenance and restoration of native forests in which these pool complexes occur
Recent progress on the chiral unitary approach to meson meson and meson baryon interactions
We report on recent progress on the chiral unitary approach, analogous to the
effective range expansion in Quantum Mechanics, which is shown to have a much
larger convergence radius than ordinary chiral perturbation theory, allowing
one to reproduce data for meson meson interaction up to 1.2 GeV. Applications
to physical processes so far unsuited for a standard chiral perturbative
approach are presented. Results for the extension of these ideas to the meson
baryon sector are discussed, together with applications to kaons in a nuclear
medium and atoms.Comment: Contribution to the KEK Tanashi Symposium on Physics of Hadrons and
Nuclei, Tokyo, December 1998, 10 pages, 3 postscript figures. To be published
as a special issue of Nuclear Physics
Intelligence and personality as predictors of illness and death: How researchers in differential psychology and chronic disease epidemiology are collaborating to understand and address health inequalities
Study of doubly strange systems using stored antiprotons
Bound nuclear systems with two units of strangeness are still poorly known despite their importance for many strong interaction phenomena. Stored antiprotons beams in the GeV range represent an unparalleled factory for various hyperon-antihyperon pairs. Their outstanding large production probability in antiproton collisions will open the floodgates for a series of new studies of systems which contain two or even more units of strangeness at the PâŸANDA experiment at FAIR. For the first time, high resolution Îł-spectroscopy of doubly strange ÎÎ-hypernuclei will be performed, thus complementing measurements of ground state decays of ÎÎ-hypernuclei at J-PARC or possible decays of particle unstable hypernuclei in heavy ion reactions. High resolution spectroscopy of multistrange Îâ-atoms will be feasible and even the production of Ωâ-atoms will be within reach. The latter might open the door to the |S|=3 world in strangeness nuclear physics, by the study of the hadronic Ωâ-nucleus interaction. For the first time it will be possible to study the behavior of ÎâŸ+ in nuclear systems under well controlled conditions