Can the whole life cost of railway track be reduced through the effective management of tangential wheel-rail loading?

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Medicines prescribed for asthma, discontinuation and perinatal outcomes, including breastfeeding: A population cohort analysis

ObjectivesTo explore associations between exposures to medicines prescribed for asthma and their discontinuation in pregnancy and preterm birth [MethodsDesign. A population-based cohort study. Setting. The Secure Anonymised Information Linkage [SAIL] databank in Wales, linking maternal primary care data with infant outcomes. Population. 107,573, 105,331, and 38,725 infants born 2000-2010 with information on premature birth, SGA and breastfeeding respectively, after exclusions. Exposures. maternal prescriptions for asthma medicines or their discontinuation in pregnancy. Methods. Odds ratios for adverse pregnancy outcomes were calculated for the exposed versus the unexposed population, adjusted for smoking, parity, age and socio-economic status.ResultsPrescriptions for asthma, whether continued or discontinued during pregnancy, were associated with birth atConclusionsPrescription of asthma medicines before or during pregnancy was associated with higher prevalence of adverse perinatal outcomes, particularly if prescriptions were discontinued during pregnancy. Women discontinuing medicines during pregnancy could be identified from prescription records. The impact of targeting close monitoring and breastfeeding support warrants exploration

Low enthalpy heat recovery potential from coal mine discharges in the South Wales Coalfield

Fossil fuels generate the majority of space heating and hot water demand in the UK, contributing to greenhouse gas emissions and energy security issues. Concerns about the long term availability of traditional fossil fuels are recognised by the UK government and sustainable, low carbon supplies are being actively investigated. One such option in the renewable energy mix is the use of low enthalpy heat, using open loop ground source technology to recover heat from abandoned flooded coal mines. To assess this potential in the South Wales Coalfield we measured annual temperatures and chemistry at sixteen mine water sites. Mean monthly temperatures ranged from 10.3 to 18.6 °C with an overall mean of 13.3 °C, proving their suitability for low enthalpy heat recovery. Collated data shows the geothermal gradient can vary within the South Wales Coalfield. Exothermic chemical reactions within abandoned mine workings can also contribute to the overall temperature of mine waters. Using discharge and temperature data we estimate that 42 MW of potential heating energy could be generated from currently monitored mine water discharges, however historic dewatering data from operational mines suggests that 72 MW could be generated, enough to heat about 6500 homes. The true potential, if new pumping wells were drilled to exploit flooded workings is likely to be much greater. The use of low enthalpy mine water for space heating and hot water indicate a total emission reduction of around 59% and 76% compare to main gas and electricity heating respectively

Monitoring groundwater temperatures in a shallow urban aquifer before, during and after installation of a Ground Source Heat System in Cardiff, U.K.

Exploitation of shallow urban aquifers, warmed by the Urban Heat Island Effect, is a relatively new concept in the U.K. An extensive groundwater temperature baseline monitoring network has been established for a shallow superficial aquifer in the city of Cardiff, U.K., to characterise groundwater temperatures and monitor the impacts of the first open-loop ground source heat pump (GSHP) installed in the city. In Spring 2014, temperature profiling was carried out at 1m depth intervals at 168 groundwater monitoring boreholes across Cardiff, establishing baseline groundwater temperatures within the shallow (<20m) superficial aquifer during the groundwater’s forecast coldest time of year. Data was contoured to form the first U.K. 2D city heat map. During the warmest time of year, Autumn 2014, a subset of boreholes were re-profiled to ascertain seasonal temperature variation, defining the Zone of Seasonal Fluctuation. Re-profiling was again carried out at these boreholes in Autumn 2015 to confirm these temperatures as normal for that time of year. By comparing Spring and Autumn profiles, the average depth to the base of the Zone of Seasonal Fluctuation was found to be 9.5mbgl. Two >100m boreholes showed the urban warming effect may extend to 80mbgl, before temperatures follow the predicted geothermal gradient. We term this the Zone of Anthropogenic Influence. After initial baseline temperatures were established, a site was selected for the installation of a shallow GSHP. Before installation work began, a monitoring network was set up to establish a temperature baseline for future GSHPs and identify any impacts on the thermal resource caused by removing ~2°C from the abstracted groundwater prior to reinjection into the aquifer. This comprised of 97 temperature loggers in 60 boreholes, including the abstraction and recharge boreholes and boreholes up and down gradient of the site. Some of these boreholes have multiple loggers at different depths, including the near-surface, but the majority of loggers were placed within the boreholes’ slotted sections, below the base of the Zone of Seasonal Fluctuation. In addition, six boreholes, including those used for the GSHP, have been telemetered, providing real-time temperature data. The aim of the monitoring network was to establish a baseline for groundwater temperatures in the shallow aquifer and to monitor local changes in temperatures close to the GSHP system. This study aimed to provide understanding of how GSHPs interact with the groundwater in order to confirm the sustainability of groundwater temperatures as a long-term thermal resource and provide planners with knowledge needed to develop sustainable wide-scale GSHP systems/networks. We present temperature data taken before and after installation

Antidepressant prescriptions, discontinuation, depression and perinatal outcomes, including breastfeeding: A population cohort analysis

ObjectivesTo explore associations between exposure to antidepressants, their discontinuation, depression [medicated or unmediated] and preterm birth [MethodsDesign: A population-based cohort study. Setting: The Secure Anonymised Information Linkage [SAIL] databank in Wales, linking maternal primary care data with infant outcomes. Participants: 107,573, 105,331, and 38,725 infants born 2000-2010 with information on prematurity, SGA and breastfeeding respectively, after exclusions. Exposures: Maternal antidepressant prescriptions in trimesters 2 or 3, discontinuation after trimester 1, recorded diagnosis of depression [medicated or unmediated] in pregnancy. Methods: Odds ratios for adverse pregnancy outcomes were calculated, adjusted for smoking, parity, socio-economic status, and depression.ResultsExclusive formula feeding at 6-8 weeks was associated with prescriptions in trimesters 2 or 3 for any antidepressants (adjusted odds ratio [aOR] 0.81, 95% confidence intervals 0.67-0.98), SSRIs [aOR 0.77, 0.62-0.95], particularly higher doses [aOR 0.45, 0.23-0.86], discontinuation of antidepressants or SSRIs after trimester 1 (aOR 0.70, 0.57-0.83 and 0.66, 0.51-0.87), diagnosis of depression aOR 0.76 [0.70-0.82), particularly if medicated (aOR 0.70, 0.58-0.85), rather than unmedicated (aOR 0.87, 0.82-0.92). Preterm birth at ImplicationsExposure to antidepressants or depression increased risks of exclusive formula feeding at 6-8 weeks, and prescription of antidepressants was associated with SGA <3rd centile. Prescription of antidepressants offers a useful marker to target additional support and additional care before and during pregnancy and lactation

Deployment of Available Rail Steels to Reduce Life Cycle Costs

The rate of rail degradation and hence its expected life is not uniform throughout any railway network and is governed by a combination of track, traffic and operating characteristics in addition to the metallurgical attributes of the steel. Consequently, it is suggested that any route or network is not a single linear asset but is a compilation of individual segments with different track characteristics, degradation rates and expected life spans. Thus, the choice of rail steel grade to maximise life span needs to combine the knowledge of the metallurgical attributes of the available rail steels with the conditions prevailing at the wheel-rail and vehicle-track interfaces. This approach has been the focus of research at the University of Huddersfield Institute of Railway Research (IRR) and this paper describes some of the results from the EPSRC/RSSB/DfT sponsored project entitled “Designing Steel Composition and Microstructure to Better Resist Degradation during Wheel-Rail Contact”. The paper is focussed on: - Classification of the susceptibility to rail degradation in various parts of a mixed-traffic network. - Metallurgical attributes of the currently available rail steel

Track loading limits and cross-acceptance of vehicle approvals

The requirements for track loading limits are one of the main barriers to simple cross-acceptance of vehicles where rolling stock that is already operating successfully in one (or more) networks has to be retested before it can be approved for operation on another network. DynoTRAIN Work Package 4 studied this area in order to determine whether the additional requirements were justified, or if the process could be made much cheaper and simpler without increasing the risk of track deterioration for the networks. The review of national requirements identified modified criteria and limit values for track forces in some member states; however, these can be obtained from additional analysis of the normal test results with no new tests required. The influence of design rail inclination has also been found not to be significant, provided a realistic range of wheel–rail contact conditions are included in the tests. For line speeds greater than or equal to 160 km/h, the current standards for track construction across the member states appear to be similar. On lower speed lines in some countries, a ‘weaker’ track condition may require a lower limit on one of the vehicle assessment parameters. Track dynamics modelling has shown that the vehicle assessment parameters used in international standards are suitable for use in cross-acceptance for track forces. The use of multiple regression analysis allows the estimated maximum value for relevant parameters to be evaluated for different target conditions and then compared with the appropriate limit value, or with values for existing, comparable vehicles. Guidance has also been provided on the relevant parameters to consider when developing operating controls for different types of track deterioration