The influence of long term trends in pollutant emissions on deposition of sulphur and nitrogen and exceedance of critical loads in the United Kingdom

In the United Kingdom, as with other European countries, land-based emissions of NOX and SO2 have fallen significantly over the last few decades. SO2 emissions fell from a peak of 3185 Gg S in 1970 to 344 Gg S in 2005 and are forecast by business-as-usual emissions scenarios to fall to 172 Gg by 2020. NOX emissions were at a maximum of 951 Gg N in 1970 and fell to 378 by 2005 with a further decrease to 243 Gg N forecast by 2020. These large changes in emissions have not been matched by emissions changes for NH3 which decreased from 315 Gg N in 1990 to 259 in 2005 and are forecast to fall to 222 by 2020. The Fine Resolution Atmospheric Multi-pollutant Exchange model (FRAME) has been applied to model the spatial distribution of sulphur and nitrogen deposition over the United Kingdom during a 15 year time period (1990-2005) and compared with measured deposition of sulphate, nitrate and ammonium from the national monitoring network. Wet deposition of nitrogen and sulphur was found to decrease more slowly than the emissions reductions rate. This is attributed to a number of factors including increases in emissions from international shipping and changing rates of atmospheric oxidation. The modelled time series was extended to a 50 year period from 1970 to 2020. The modelled deposition of SOx, NOy and NHx to the UK was found to fall by 87%, 52% and 25% during this period. The percentage of the United Kingdom surface area for which critical loads are exceeded is estimated to fall from 85% in 1970 to 37% in 2020 for acidic deposition and from 73% to 49% for nutrient nitrogen deposition. The significant reduction in land emissions of SO2 and NOX focuses further attention in controlling emissions from international shipping. Future policies to control emissions of ammonia from agriculture will be required to effect further significant reductions in nitrogen deposition

Gamma radiation characteristics of plutonium dioxide fuel

Net gamma ray source intensity and spectrum for plutonium dioxide fuel element

Characterisation of porous solids using small-angle scattering and NMR cryoporometry

The characteristics of several porous systems have been studied by the use of small-angle neutron scattering [SANS] and nuclear magnetic resonance [NMR] techniques. The measurements reveal different characteristics for sol-gel silicas, activated carbons and ordered mesoporous silicas of the MCM and SBA type. Good agreement is obtained between gas adsorption measurements and the NMR and SANS results for pore sizes above 10 nm. Recent measurements of the water/ice phase transformation in SBA silicas by neutron diffraction are also presented and indicate a complex relationship that will require more detailed treatment in terms of the possible effects of microporosity in the silica substrate. The complementarity of the different methods is emphasised and there is brief discussion of issues related to possible future developments

Change of Position and Estoppel as Defences to an \u27Action for Money Paid by Mistake

The recent decision in RBC Dominion Securities Inc.v. Dawson\u27 raises some interesting questions regarding the defences available to a claim in restitution for the recovery of money paid by mistake. At issue were the, defences of change of position and estoppel. Both defences are recognized in Canadian law, but questions remain regarding their limits and their relationship

The Consumer Product Warranty and Liability Act

This article provides a roadmap for the Consumer Product Warranty and Liability Act. The Act reformed and modernized much of the law regarding the sale or supply of consumer products, not only for consumers but also for business buyers. The Act deals with the following matters: express warranties; implied warranties; remedies; the supplier's ability to limit liability; the supplier's rights against his own supplier; rights against the manufacturer or other distributor regardless of privity of contract; and the imposition of strict liability on suppliers for unreasonably dangerous defective products.Cet article illustre un plan de la loi sur la responsabilité et les garanties relatives aux produits de consommation. Cet acte a reformé et modernisé considérablement la loi concernant la vente ou la fourniture de produit de consommation, non seulement au point de vue du consommateur mais aussi au point de vue de l'acheteur en activité commerciale. L'acte traite des sujets suivant: garanties expresses; garanties tacites; recours; abilité du fournisseur de limiter sa responsabilité; recours du fournisseur contre ses propre fournisseurs; recours contre le manufacturier où des autres distributeurs même en l'absence de liens contractuels; la responsabilité des fournisseurs pour un produit de consommation dangereux

(Chloromethyl)pentacarbonylmanganese(I): a crystal structure with a non-crystallographic centre of symmetry

There are two molecules in the asymmetric unit of the P2₁/c unit cell of ClCH₂Mn(CO)₅, the first halomethyl complex of manganese to be structurally determined. The molecules are crystallographically independent, despite an apparent local centre of symmetry. The average bond parameters include Mn–Calkyl 2.128(8) Å, C–Cl 1.811(8) Å and Mn–C–Cl 116.4(4)