2,915 research outputs found

    Energy storage in the UK electrical network : estimation of the scale and review of technology options

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    This paper aims to clarify the difference between stores of energy in the form of non-rechargeable stores of energy such as fossil-fuels, and the storage of electricity by devices that are rechargeable. The existing scale of these two distinct types of storage is considered in the UK context, followed by a review of rechargeable technology options. The storage is found to be overwhelmingly contained within the fossil-fuel stores of conventional generators, but their scale is thought to be determined by the risks associated with long supply chains and price variability. The paper also aims to add to the debate regarding the need to have more flexible supply and demand available within the UK electrical network in order to balance the expected increase of wind derived generation. We conclude that the decarbonisation challenge facing the UK electricity sector should be seen not only as a supply and demand challenge but also as a storage challenge. (c) 2010 Elsevier Ltd. All rights reserved

    Isolation and characterization of microsatellites in the lichen Buellia frigida (Physciaceae), an Antarctic endemic

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    Premise of the study: Microsatellite markers were characterized for an Antarctic endemic, Buellia frigida, to investigate population structure and origin of Antarctic lichens. Methods and Results: Five primer sets were characterized. All loci were polymorphic with eight to 16 alleles per locus in a sample of 59 lichens. Conclusions: The microsatellite markers potentially provide insight into population structure and gene flow of B. frigida

    The Wider Social Impacts of Changes in the Structure of Agricultural Businesses

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    Agricultural restructuring is not a new phenomenon. Indeed, recent decades have seen substantial changes, not only to the number and types of farmers and farm businesses, but also to ownership structures and to the relationship between land holding and management control. The Department of Food, Environment and Rural Affairs (Defra), together with the UK Countryside Agencies, has commissioned a body of research in recent years which, taken together, offer important insights into the nature, speed and extent of restructuring in the UK and of the potential for further, accelerated change in the years to come. From this body of work it is clear that a prolonged and difficult process of disengagement from agriculture as a mainstream income source is beginning to take place, with evidence of both adaptation and resistance to change by a land management community which is becoming increasingly diverse in its social composition and behaviour. The adjustment to farming practice, living standards and lifestyles which all of this implies is not without personal cost and, while claims of an agricultural crisis may be exaggerated, it is clear that large numbers of farmers are finding they have to make difficult adjustments against a shifting background of policy reform and market change. Moreover, given the traditional centrality of farmers in rural communities, both as employers and as participants in many of the key institutions of rural life, there may be wider social implications of agricultural restructuring which now deserve to be more closely investigated. What, for example is the nature, extent and wider significance of the personal costs and social implications of agricultural restructuring.Agribusiness, Industrial Organization,

    Using Passive Samplers to Track per and Polyfluoroalkyl Substances (PFAS) Emissions From the Paper Industry: Laboratory Calibration and Field Verification

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    Per and polyfluoroalkyl substances (PFAS) are becoming more stringently regulated and as such, a more diverse suite of environmental monitoring methods is needed. In this work a polar organic chemical integrative sampler (POCIS) with a nylon membrane and a combination of Oasis WAX and Fluoroflash® sorbents was calibrated in the laboratory and deployed in the field. A static renewal system was used to determine sampling rates for 12 PFAS which ranged between 0.69 ± 0.27 to 5.68 ± 1.80 L/day. POCIS devices were deployed for 10 days in lake Tyrifjorden, Norway which is known to be contaminated by a closed down factory producing paper products, in order to track the evolution of the PFAS contamination in a river system draining into the lake. Th sampling campaign enabled the stretch of the river which was responsible for the emissions of PFAS to lake Tyrifjorden to be identified. Freely dissolved concentrations determined with the POCIS were lowest at the site considered to reflect a diffuse PFAS contamination and highest at the site located downstream the factory. Perfluorooctanesulfonic acid (PFOS), perfluorohexanoic acid (PFHxA) and perfluorooctane sulfonamidoacetic acid (EtFOSAA) dominated the concentration profile at this site. Emissions of PFAS to lake Tyrifjorden were estimated to be 3.96 g/day for the sum of the 12 investigated PFAS.publishedVersio

    Study of diffusion weighted MRI as a predictive biomarker of response during radiotherapy for high and intermediate risk squamous cell cancer of the oropharynx: The MeRInO study

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    Introduction and background: A significant proportion of patients with intermediate and high risk squamous cell cancer of the oropharynx (OPSCC) continue to relapse locally despite radical chemoradiotherapy (CRT). The toxicity of the current combination of intensified dose per fraction radiotherapy and platinum based chemotherapy limits further uniform intensification. If a predictive biomarker for outcomes from CRT can be identified during treatment then individualised and adaptive treatment strategies may be employed. Methods/design: The MeRInO study is a prospective observational imaging study of patients with intermediate and high risk, locally advanced OPSCC receiving radical RT or concurrent CRT Patients undergo diffusion weighted MRI prior to treatment (MRI_1) and during the third week of RT (MRI_2). Apparent diffusion coefficient (ADC) measurements will be made on each scan for previously specified target lesions (primary and lymph nodes) and change in ADC calculated. Patients will be followed up and disease status for each target lesion noted. The primary aim of the MeRInO study is to determine the threshold change in ADC from baseline to week 3 of RT that may identify the sub-group of non-responders during treatment. Discussion: The use of DW-MRI as a predictive biomarker during RT for SCC H&N is in its infancy but studies to date have found that response to treatment may indeed be predicted by comparison of DW-MRI carried out before and during treatment. However, previous studies have included all sub-sites and biological sub-types. Establishing ADC thresholds that predict for local failure is an essential step towards using DW-MRI to improve the therapeutic ratio in treating SCC H&N. This would be done most robustly in a specific H&N sub-site and in sub-types with similar biological behaviour. The MeRInO study will help establish these thresholds in OPSCC

    Are routinely collected NHS administrative records suitable for endpoint identification in clinical trials? Evidence from the West of Scotland coronary prevention study

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    Background: Routinely collected electronic patient records are already widely used in epidemiological research. In this work we investigated the potential for using them to identify endpoints in clinical trials.<p></p> Methods: The events recorded in the West of Scotland Coronary Prevention Study (WOSCOPS), a large clinical trial of pravastatin in middle-aged hypercholesterolaemic men in the 1990s, were compared with those in the record-linked deaths and hospitalisations records routinely collected in Scotland.<p></p> Results: We matched 99% of fatal study events by date. We showed excellent matching (97%) of the causes of fatal endpoint events and good matching (.80% for first events) of the causes of nonfatal endpoint events with a slightly lower rate of mismatching of record linkage than study events (19% of first study myocardial infarctions (MI) and 4% of first record linkage MIs not matched as MI). We also investigated the matching of non-endpoint events and showed a good level of matching, with .78% of first stroke/TIA events being matched as stroke/TIA. The primary reasons for mismatches were record linkage data recording readmissions for procedures or previous events, differences between the diagnoses in the routinely collected data and the conclusions of the clinical trial expert adjudication committee, events occurring outside Scotland and therefore being missed by record linkage data, miscoding of cardiac events in hospitalisations data as ‘unspecified chest pain’, some general miscoding in the record linkage data and some record linkage errors.<p></p> Conclusions: We conclude that routinely collected data could be used for recording cardiovascular endpoints in clinical trials and would give very similar results to rigorously collected clinical trial data, in countries with unified health systems such as Scotland. The endpoint types would need to be carefully thought through and an expert endpoint adjudication committee should be involved.<p></p&gt

    The inferior turbinate flap in skull base reconstruction

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    BACKGROUND: As the indications for expanded endonasal approaches continue to evolve, alternative reconstructive techniques are needed to address increasingly complex surgical skull base defects. In the absence of the nasoseptal flap, we describe our experience with the posterior pedicle inferior turbinate flap (PPITF) in skull base reconstruction. DESIGN: Case series. SETTING: Academic tertiary care centre. METHODS: Patients who underwent reconstruction of the skull base with the PPITF were identified. Medical records were reviewed for demographic, presentation, treatment, follow-up, surgical and outcomes data. MAIN OUTCOME MEASURES: Flap survival, adequacy of seal, and complications. RESULTS: Two patients with residual/recurrent pituitary adenomas met the inclusion criteria. The nasoseptal flap was unavailable in each case due to a prior septectomy. Salvage of the original nasoseptal flap was not possible, as it did not provide adequate coverage of the resultant defect due to contraction from healing. All PPITFs healed uneventfully and covered the entire defect. No complications were observed in the early post-operative period. Endoscopic techniques and limitations of the PPITF are also discussed. CONCLUSIONS: Our clinical experience supports the PPITF to be a viable alternative for reconstruction of the skull base in the absence of the nasoseptal flap

    Assessing the potential of autonomous submarine gliders for ecosystem monitoring across multiple trophic levels (plankton to cetaceans) and pollutants in shallow shelf seas

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    A combination of scientific, economic, technological and policy drivers is behind a recent upsurge in the use of marine autonomous systems (and accompanying miniaturized sensors) for environmental mapping and monitoring. Increased spatial–temporal resolution and coverage of data, at reduced cost, is particularly vital for effective spatial management of highly dynamic and heterogeneous shelf environments. This proof-of-concept study involves integration of a novel combination of sensors onto buoyancy-driven submarine gliders, in order to assess their suitability for ecosystem monitoring in shelf waters at a variety of trophic levels. Two shallow-water Slocum gliders were equipped with CTD and fluorometer to measure physical properties and chlorophyll, respectively. One glider was also equipped with a single-frequency echosounder to collect information on zooplankton and fish distribution. The other glider carried a Passive Acoustic Monitoring system to detect and record cetacean vocalizations, and a passive sampler to detect chemical contaminants in the water column. The two gliders were deployed together off southwest UK in autumn 2013, and targeted a known tidal-mixing front west of the Isles of Scilly. The gliders’ mission took about 40 days, with each glider travelling distances of >1000 km and undertaking >2500 dives to depths of up to 100 m. Controlling glider flight and alignment of the two glider trajectories proved to be particularly challenging due to strong tidal flows. However, the gliders continued to collect data in poor weather when an accompanying research vessel was unable to operate. In addition, all glider sensors generated useful data, with particularly interesting initial results relating to subsurface chlorophyll maxima and numerous fish/cetacean detections within the water column. The broader implications of this study for marine ecosystem monitoring with submarine gliders are discussed

    CO2 reduction through low cost electrification of the diesel powertrain at 48V

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    In order to achieve fleet average CO2 targets, mass market adoption of low CO2 technologies is required. Application of low cost technologies across a large number of vehicles is more cost-effective in reducing fleet CO2 than deploying high-impact, costly technology to a few. Therefore, to meet the CO2 reduction challenge, commercially viable, low cost technologies are of significant interest. This paper presents results from the ‘ADEPT’ collaborative research program which focuses on CO2 reduction through the application of intelligent 48V electrification to diesel engines for passenger car applications. Results were demonstrated on a C-segment vehicle with a class-leading 4-cylinder 1.5 litre Euro 6 diesel engine. Electrification was applied through a high power, high efficiency, switched reluctance belt integrated starter generator (B-ISG) capable of both generation and motoring, and an Advanced Lead Carbon Battery for energy storage. The conventional alternator was replaced with a highly efficient DC-DC converter to supply energy to the 12V system. These technologies enabled powertrain efficiency improvement through the recovery of kinetic energy with regenerative braking and reapplication of the recovered energy through motoring to offset fuel usage. Efficiency was further optimised through application of engine downspeeding and advanced auto-stop strategies to extended engine-off time. Additional electrification was investigated through 48V ancillaries, including water-pump and air-conditioning compressor, and a turbo-compound generator for waste heat recovery from exhaust gas. These technologies have demonstrated a combined CO2 reduction of 10–11% against the conventional vehicle baseline. Additional studies of advanced thermal systems for improved warm-up, and lubrication control for FMEP reduction have also been conducted on this program. These indicate that by applying intelligent electrification to ancillaries a further 3–4% reduction in CO2 is achievable. Overall, this program shows that 48V technologies can achieve CO2 savings with a lower cost per gram CO2 than full hybrid solutions
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