112 research outputs found
Moving radiation protection on from the limitations of empirical concentration ratios
Radionuclide activity concentrations in food crops and wildlife are most often predicted using empirical concentration ratios (CRs). The CR approach is simple to apply and some data exist with which to parameterise models. However, the parameter is highly variable leading to considerable uncertainty in predictions. Furthermore, for both crops and wildlife we have no, or few, data for many radionuclides and realistically, we are never going to have specific data for every radionuclide - wildlife/crop combination. In this paper, we present an alternative approach using residual maximum likelihood (REML) fitting of a linear mixed effects model; the model output is an estimate of the rank-order of relative values. This methodology gives a less uncertain approach than the CR approach, as it takes into account the effect of site; it also gives a scientifically based extrapolation approach. We demonstrate the approach using the examples of Cs for plants and Pb for terrestrial wildlife. This is the first published application of the REML approach to terrestrial wildlife (previous applications being limited to the consideration of plants). The model presented gives reasonable predictions for a blind test dataset
Bamboo reinforced concrete: a critical review
© 2018, The Author(s). The use of small diameter whole-culm (bars) and/or split bamboo (a.k.a. splints or round strips) has often been proposed as an alternative to relatively expensive reinforcing steel in reinforced concrete. The motivation for such replacement is typically cost—bamboo is readily available in many tropical and sub-tropical locations, whereas steel reinforcement is relatively more expensive—and more recently, the drive to find more sustainable alternatives in the construction industry. This review addresses such ‘bamboo-reinforced concrete’ and assesses its structural and environmental performance as an alternative to steel reinforced concrete. A prototype three bay portal frame, that would not be uncommon in regions of the world where bamboo-reinforced concrete may be considered, is used to illustrate bamboo reinforced concrete design and as a basis for a life cycle assessment of the same. The authors conclude that, although bamboo is a material with extraordinary mechanical properties, its use in bamboo-reinforced concrete is an ill-considered concept, having significant durability, strength and stiffness issues, and does not meet the environmentally friendly credentials often attributed to it
Score a goal for climate: Assessing the carbon footprint of travel patterns of the English Premier League clubs
Football is the most popular sport, globally and in the United Kingdom. However it generates a range of negative environmental impacts, such as climate change, due to an extensive amount of travel involved. The growing contribution of football clubs to the global carbon footprint has been recognised, but never consistently assessed. This study assesses the carbon footprint of the English Premier League (EPL)clubs, using the patterns of their domestic travel in the 2016/2017 season as a proxy for analysis. The study shows that, within the 2016/17 season, the EPL clubs produced circa 1134 tonnes of CO 2- eq. as a result of their travel, where transportation accounts for 61% of the carbon footprint. To reduce this carbon footprint, a careful review of the current corporate travel and procurement practices in the EPL clubs is necessary. This is in order to optimise the travel itineraries, prioritise more climate-benign modes of transport and contract budget accommodation providers with the ‘green’ credentials
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