1,663 research outputs found

    Superior Properties of Ultra-fine-grained Steels

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    A description of the improved mechanical properties obtained in ultra-fine-grained steels up to now will be presented in this paper, and some potential applications of these new generation steels will be described. In addition, the principle and implementation of a novel hot rolling process developed by the author will be introduced. This novel Thermomechanical Nonrecrystallisation Control Process (TNCP) has been shown to give an ultra-fine ferrite (uff) structure with grain sizes of 2 to 3mm in various test steels, thus resulting in super-toughness. Charpy V impact test results suggest that some of these steels could still be tough at temperatures lower than -100 °C. This novel process, TNCP, is one potential candidate for the commercial production of superior ultra-fine-grained steels in the future

    Sustainable diets in the UK—developing a systematic framework to assess the environmental Impact, cost and nutritional quality of household food purchases

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    Sustainable diets should not only respect the environment but also be healthy and affordable. However, there has been little work to assess whether real diets can encompass all three aspects. The aim of this study was to develop a framework to quantify actual diet records for health, affordability and environmental sustainability and apply this to UK food purchase survey data. We applied a Life Cycle Assessment (LCA) approach to detailed food composition data where purchased food items were disaggregated into their components with traceable environmental impact data. This novel approach is an improvement to earlier studies in which sustainability assessments were based on a limited number of “food groups”, with a potentially high variation of actual food items within each group. Living Costs and Food Survey data for 2012, 2013 and 2014 were mapped into published figures for greenhouse gas emissions (GHGE, taking into account processing, transport and cooking) and land use, a diet quality index (DQI) based on dietary guidelines and food cost, all standardised per household member. Households were classified as having a ‘more sustainable’ diet based on GHGE, cost and land use being less than the median and DQI being higher than the median. Only 16.6% of households could be described as more sustainable; this rose to 22% for those in the lowest income quintile. Increasing the DQI criteria to >80% resulted in only 100 households being selected, representing 0.8% of the sample. The framework enabled identification of more sustainable households, providing evidence of how we can move toward better diets in terms of the environment, health, and costs

    Effects of alternative uses of distillery by-products on the greenhouse gas emissions of Scottish malt whisky production: a system expansion approach

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    Agricultural by-products are an important component of livestock feed. In Scotland, distillery by-products are protein rich and traditionally cost competitive feed ingredients in cattle production. However, during recent years, distilleries in the UK (including Scotch whisky producers) have started to use the by-products also as a source of renewable energy, in order to reduce the carbon footprint of alcohol production. In this study, a systems-based material and energy flow analysis was performed to calculate the life-cycle greenhouse gas (GHG) emissions of whisky production for two scenarios where distillery by-products were used either (1) as beef cattle feed to replace other protein sources (namely soya bean meal and rapeseed meal); or (2) as anaerobic digester (AD) feedstock in order to generate renewable energy (heat and electricity). System expansion was used to quantitatively handle the by-products in the analysis. The results show that considerable reductions in GHG emissions could be achieved by either replacing feed crops with by-products or by using the by-products in AD plants to generate bio-energy. The biggest reductions in the GHG emissions were achieved when by-products were used to replace soya meal in animal feed. However, the results are highly sensitive to methodological choices, including the accounting method of the land use change emissions arising from soya production

    Sea lice management measures for farmed Atlantic salmon (Salmo salar) in Scotland: Costs and effectiveness

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    Cultured and wild Atlantic salmon around the world are affected by sea lice. Salmon culturing countries have policies in place to minimize sea lice abundance on cultured salmon in open net pens in the marine environment. To adhere to these policies, salmon producers deploy a range of management measures against sea lice throughout the production cycle. The cost effectiveness of these sea lice management measures is not well quantified. This study provides estimates for cost effectiveness in Scotland of (1) individual sea lice management measures and (2) integrated management strategies that span an entire production cycle. Estimates were based on the cost-effectiveness ratio, in which costs consist of those associated with equipment, implementation, environment and side effects (mortality). Effectiveness was based on interviews and expert opinions. For single measures, skirts and the use of in-feed medicines had the best cost-effectiveness. Cleaner fish, fresh or brackish water baths, the physical removal measures (thermolicer and hydrolicer) and medicinal baths were among the next most cost-effective measures, followed by hydrogen peroxide baths. Tarpaulins were more cost-effective than well boats due to lower costs under the assumption of equal effectiveness. Direct comparison of cost effectiveness among measures may not always be constructive as they are deployed at different times in the production cycle and their functionality is different. A holistic approach to sea lice management, a common practice in industry as shown by the integrated management strategies, may reduce risk of developing resistance. For the single measures, carbon costs were insignificant compared to other costs. If measures would have a lasting effect on production through to harvest, such as ongoing increased mortality as a result of a management measure, carbon costs may become significant. Better quantification of effectiveness is important because the scarcity of data led to uncertainty that had a large impact on cost-effectiveness estimates. Generally, this study demonstrated a lack of reliable publicly available data and lack of standardization of data, which constrains research. Highlighted gaps in knowledge can serve as a guide to improve further understanding.<br/

    Replacement of soya bean meal with peas and faba beans in growing/finishing pig diets: effect on performance, carcass composition and nutrient excretion

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    There is now an increasing debate about the viability of using temperate-grown legumes in pig diets as a potential replacement for imported soya bean meal (SBM) and this is due to food security, sustainability and environmental concerns. Two trials were designed to examine nitrogen (N) retention, growth performance and carcass quality of grower and finisher pigs when fed nutritionally balanced SBM-free diets formulated to contain peas or faba beans at 300 g/kg, compared to an SBM-containing, pulse-free control diet. Trial 1 evaluated N digestibility/retention in four iso-energetic diets, comparing the SBM control with one diet formulated with peas and two with faba bean cultivars; a tannin-containing and a tannin-free variety. This trial employed a four by four Latin Square design with four male pigs housed in metabolism crates, fed twice daily at 0.9 of assumed ad libitum intake over four time periods during grower (30–55 kg) and finisher (55–95 kg) phases. Quantitative faecal and urine collection allowed determination of N coefficient of total tract apparent digestibility, coefficient of apparent metabolisability, and N balance. Results revealed that dietary treatment did not affect these N parameters (P > 0.05) during either the grower or finisher phase. Trial 2 evaluated growth performance (feed intake, daily live weight gain and feed conversion ratio) and carcass quality parameters. Five diets (based on SBM, peas and one of three faba bean cultivars) balanced for standard ileal digestible amino acids and net energy were each fed to eight replicates of individually housed entire male pigs over the same growth phases as Trial 1. The inclusion of three faba bean varieties allowed comparison of animal responses between tannin/tannin-free and spring vs. winter bean cultivars. At ∼95 kg, pigs were slaughtered and a comprehensive range of carcass measurements undertaken. Samples of shoulder backfat were also taken at slaughter to determine skatole and indole concentrations. As with N balance, feeding treatment did not affect performance data. Carcass parameters revealed pigs fed with the pea-based diet had a greater dressing percentage than those animals on faba bean-based diets. Pigs fed with the SBM or pea-based diets also had greater lean meat percentages than those on faba-bean diets. Mean skatole concentrations for all pigs were below the accepted maximum threshold level of 0.2 μg/g. In conclusion, it is suggested that peas and faba beans can be successfully fed in balanced pig diets throughout the grower/finisher periods as alternatives to SBM

    Local adaptation in natural European host grass populations with asymmetric symbiosis

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    Recent work on microbiomes is revealing the wealth and importance of plant-microbe interactions. Microbial symbionts are proposed to have profound effects on fitness of their host plants and vice versa, especially when their fitness is tightly linked. Here we studied local adaptation of host plants and possible fitness contribution of such symbiosis in the context of abiotic environmental factors. We conducted a four-way multi-year reciprocal transplant experiment with natural populations of the perennial grass Festuca rubra s.l. from northern and southern Finland, Faroe Islands and Spain. We included F. rubra with and without transmitted symbiotic fungus Epichloë that is vertically transmitted via host seed. We found local adaptation across the European range, as evidenced by higher host fitness of the local geographic origin compared with nonlocals at three of the four studied sites, suggesting that selection pressures are driving evolution in different directions. Abiotic factors did not result in strong fitness effects related to Epichloë symbiosis, indicating that other factors such as herbivory are more likely to contribute to fitness differences between plants naturally occurring with or without Epichloë. Nevertheless, in the case of asymmetric symbiosis that is obligatory for the symbiont, abiotic conditions that affect performance of the host, may also cause selective pressure for the symbiont.</p
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