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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jenvman.2006.07.007 Byline: W.J. Bealey (a), A.G. McDonald (a), E. Nemitz (a), R. Donovan (b), U. Dragosits (a), T.R. Duffy (c), D. Fowler (a) Keywords: Air pollution; Particulates; Land use planning Abstract: Trees have been widely quoted as effective scavengers of both gaseous and particulate pollutants from the atmosphere. Recent work on the deposition of urban aerosols onto woodland allows the effect of tree planting strategies on airborne aerosol concentrations to be quantified and considered within the planning process. By identifying the potential planting locations in the local authority area, and applying them within a dispersion and deposition model, the potential magnitude of reduction in the ambient concentration of PM.sub.10, achievable through urban tree planting, has been quantified for two UK cities. As part of the Environmental Information Systems for Planners (EISP), flow diagrams, based on planning decisions, have incorporated output from the model to make decisions on land use planning ranging from development plans and strategic planning, to development control. In this way, for any new developments that contribute to the local PM.sub.10 level, the mitigation by planting trees can be assessed, and in some cases, reductions can be sufficient to meet air quality objectives for PM.sub.10. Author Affiliation: (a) Centre for Ecology and Hydrology, Edinburgh, Bush Estate, Penicuik, Midlothian, EH26 0QB, UK (b) School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK (c) British Geological Survey, Murchison House, West Mains Road, Edinburgh EH9 3LA, UK Article History: Received 25 April 2005; Revised 24 May 2006; Accepted 13 July 2006

Trees are efficient scavengers of particulate matter and are characterised by higher rates of dry deposition than other land types. To estimate the potential of urban tree planting for the mitigation of urban PM10 concentrations, an atmospheric transport model was used to simulate the transport and deposition of PM10 across two UK conurbations (the West Midlands and Glasgow). Tree planting was simulated by modifying the land cover database, using GIS techniques and field surveys to estimate reasonable planting potentials. The model predicts that increasing total tree cover in West Midlands from 3.7% to 16.5% reduces average primary PM10 concentrations by 10% from 2.3 to 2.1μgm−3 removing 110ton per year of primary PM10 from the atmosphere. Increasing tree cover of the West Midlands to a theoretical maximum of 54% by planting all available green space would reduce the average PM10 concentration by 26%, removing 200ton of primary PM10 per year. Similarly, for Glasgow, increasing tree cover from 3.6% to 8% reduces primary PM10 concentrations by 2%, removing 4ton of primary PM10 per year. Increasing tree cover to 21% would reduce primary PM10 air concentrations by 7%, removing 13ton of primary PM10 per year. [Copyright &y& Elsevier]

There is substantial uncertainty in the effectiveness of measures to reduce emissions of agricultural trace gases, including ammonia (NH3), methane (CH4) and nitrous oxide (N2O). The only way to test whether emission abatement programmes are successful is through monitoring of air concentrations and deposition. However, where NH3 emissions have been reduced in Europe, either through abatement policies or reductions in agricultural activity, it was difficult to demonstrate the link with reduced concentrations and deposition.The outbreak of Foot and Mouth Disease (FMD) in Great Britain in 2001 provides a major case study to test the link between agricultural emissions and air concentrations. This paper examines the spatial distribution of anticipated change in emissions and concentrations of NH3, CH4 and N2O as a result of the FMD outbreak. It then assesses the extent to which atmospheric monitoring could be used to detect the changes and attribute them to the effect of FMD. Two of the areas worst affected by FMD were selected for detailed analysis: in Cumbria (N.W. England) and in Devon (S.W. England). Compared with values prior to FMD, average agricultural emissions were reduced by as much as 50–100%, with estimated reductions in atmospheric mixing ratios of 0.7–3.3 ppb for NH3, 10–60 ppb for CH4 and 0.1–0.7 ppb for N2O.For NH3 and CH4, modelled changes are larger than the precision of analytical techniques and, where sampling is made at replicate sites, the changes are also larger than the inter-annual variability of existing monitoring data. By contrast, for N2O only the largest changes occurring in Cumbria are expected to be detectable and distinguishable from inter-annual variability. Based on the results, a measurement strategy has been established to follow NH3 and CH4 concentrations during and after the period of restocking. By comparing NH3 (a reactive gas) with CH4 (an inert tracer), the measurements aim to distinguish constraints on the link between changing emissions and air concentrations. Improving this linkage is essential to demonstrate that the economic costs of emission abatement translate into environmental benefits. [Copyright &y& Elsevier]

Highlights: [•] Devolatilisation kinetics and analytical Py-GC/MS were conducted on Nigerian teak. [•] Low ash (<1%) and N (<1%) contents and relatively high HHV (19.8MJ/kg) for teak was found. [•] Variation in E between 222 and 300kJ/mol as a function of α was observed. [•] More than one-third of the chemical constituents were phenolic organic compounds. [Copyright &y& Elsevier]

Abstract: Porous titanium alloy-bioactive glass composite coatings were manufactured via the flame spray deposition process. The porous coatings, targeted for orthodontic and bone-fixation applications, were made from bioactive glass (45S5) powder blended with either commercially pure titanium (Cp-Ti) or Ti-6Al-4V alloy powder. Two sets of spray conditions, two metallic particle size distributions, and two glass particle size distributions were used for this study. Negative control coatings consisting of pure Ti-6Al-4V alloy or Cp-Ti were sprayed under both conditions. The as-sprayed coatings were characterized through quantitative optical cross-sectional metallography, X-ray diffraction (XRD), and ASTM Standard C633 tensile adhesion testing. Determination of the porosity and glassy phase distribution was achieved by using image analysis in accordance with ASTM Standard E2109. Theoretical thermodynamic and heat transfer modeling was conducted to explain experimental observations. Thermodynamic modeling was performed to estimate the flame temperature and chemical environment for each spray condition and a lumped capacitance heat transfer model was developed to estimate the temperatures attained by each particle. These models were used to establish trends among the choice of alloy, spray condition, and particle size distribution. The deposition parameters, alloy composition, and alteration of the feedstock powder size distribution had a significant effect on the coating microstructure, porosity, phases present, mechanical response, and theoretical particle temperatures that were attained. The most promising coatings were the Ti-6Al-4V-based composite coatings, which had bond strength of 20±2MPa (n =5) and received reinforcement and strengthening from the inclusion of a glassy phase. It was shown that the use of the Ti-6Al-4V-bioactive glass composite coatings may be a superior choice due to the possible osteoproductivity from the bioactive glass, the potential ability to support tissue ingrowth and vascular tissue, and the comparable strength to similar coatings. [Copyright &y& Elsevier]

Abstract: Cold gas dynamic spraying at low pressure (1MPa gage or 150psig) was used to fabricate Al–Al2O3 metal matrix composite (MMC) coatings onto 6061 Al alloy. The powder contained Al powder admixed with −10μm Al2O3 in fractions up to 90wt.%. Scanning electron microscopy (SEM), Vickers microhardness testing, and image analysis were conducted to determine the microstructure, properties, and volume fraction of reinforcing particles in the coatings. The coatings were then friction-stir processed (FSP) at tool rotation speeds of 894 or 1723RPM using a flat cylindrical tool. The Al2O3 content and hardness of the final MMC coatings increased with increasing fractions of Al2O3 particles in the feedstock powder, resulting in a maximum Al2O3 content of 48wt.% and a hardness of 85HV of the as-sprayed coating when 90wt.% Al2O3 was used in the feed powder blend. After FSP, the hardness of the MMC increased to a maximum of 137HV. The as-sprayed coatings contained Al2O3 particles that were segregated between the Al particles, and FSP was effective in dispersing these Al2O3 particles and decreasing their mean free path. It was suggested that this re-distribution and Al2O3 particle size refinement during FSP improved the hardness of the MMC coatings. [Copyright &y& Elsevier]