Characterisation of hydraulic and hydrogeochemical processes in a reducing and alkalinity-producing system (RAPS) treating mine drainage, South Wales, UK

A series of tracer tests has been carried out in the compost and limestone Tan-y-Garn Reducing and Alkalinity-Producing System (RAPS), designed to treat iron-rich net acidic mine water (mean pH 6.18, Fe = 47 mg L-1, alkalinity 1.70 meq L-1 and mineral acidity 1.82 meq L-1) in South Wales, UK. Conservative tracer breakthrough time in the RAPS basal effluent is approximately inversely related to throughflow rate. Repeat tracer tests indicate a long term decrease in hydraulic conductivity, but not in total porosity. A specific sodium chloride tracer test from June 2008 is reported, when 15 kg salt was added to a raw mine water inflow rate of 0.87 L s-1. Electrical conductivity and major ion chemistry were monitored for a 170 hour period. Sodium exhibited a retardation of 1.15 to 1.2 in the RAPS medium relative to chloride, due to cation exchange. Simple 1-D advection-diffusion analytical modelling succeeded in simulating the early portion of tracer breakthrough in the RAPS effluent. More complex analytical modelling, accounting for (i) mixing and dilution effects in the supernatant water input signature and (ii) matrix diffusion effects, was found to be required to adequately simulate the later-stage tail of the breakthrough curve in the RAPS effluent

Holocene jökulhlaups, glacier fluctuations and palaeoenvironment, Mýrdalsjökull, South Iceland

This thesis develops a chronology of jokulhlaup (glacier burst flood) activity from Myrdalsjokull in southern Iceland. Throughout the Holocene, the interaction of the volcano Katla and the overlying ice cap of Myrdalsjokull have triggered many jokulhlaups. Crucially however, our knowledge of the possible flood routes is incomplete. Flood activity to the south and east of the ice cap has been well constrained from historical and geomorphological studies, but routes to the west of the ice cap have not been fully investigated. This is important for understanding the interaction of Katla and its overlying ice cap as well as from the perspective of hazard assessment.New geomorphological, sedimentological and tephrochronological data have identified 15 flow events during the Holocene. The majority of these were hyperconcentrated flow events originating from, or close to, the northwest area of the ice cap and are associated with subglacial volcanism. One flood originated in the Veidivotn area and on 3 occasions flooding from Katla may have been accompanied by floods from Eyjafjallajokull. A further two events relate to re-mobilisation of thick airfall tephra deposits. Silicic pumice found on the sandur and close to the ice margin indicates that the Markarfljot acted as a terrestrial transport route for pumice found along North Atlantic coasts, and was possibly a route for silicic Katla jokulhlaups. Additionally, flood routes and glacial landforms show that Entujokull reached a maximum Holocene extent in the mid-Holocene, extending further downvalley than during the Little Ice Age.In prehistory, floods were directed to both the south and west of Myrdalsjokull. Similarly timed jokulhlaups took these paths when floods also flowed from Eyjafjoll into the Markarfljot. This suggests that concurrent routing of floods to the south and west of Myrdalsjokull is related to synchronous volcanic activity in Katla and Eyjafjallajokull. Since the 10th Century most Katla floods have been routed to the south east, possibly reflecting changes in intra-caldera eruption sites or subglacial topographic change associated with the Eldgja eruption in c.935 AD, as suggested by Larsen (2000).The environmental impacts of these floods were significant. Late prehistoric and early historic floods had a major role in shaping the landscape faced by the earliest Norse colonisers of the region. Future flooding could pose a distinct hazard to farmland downvalley and to popular tourist areas in North Forsmork

The relative social and economic status of Indigenous people in Bourke, Brewarrina and Walgett

This profile of the relative social and economic status of Indigenous people in Bourke, Brewarrina and Walgett was prepared at the request of the New South Wales State Office of the Aboriginal and Torres Strait Islander Commission (ATSIC) to inform discussions to be held between ATSIC Commissioner Steve Gordon, Indigenous representatives from Far West New South Wales and the Deputy Prime Minister, John Anderson. The focus of these discussions is to explore solutions to pressing social and economic problems facing Indigenous communities in these three towns. The report provides a range of social indicators constructed from a variety of published and unpublished sources including the Census of Population and Housing as well as administrative data sets held by ATSIC, Commonwealth and New South Wales government departments, and other locally-based Aboriginal organisations. This process was assisted by consultations with key informants in each of the three towns and with relevant agencies in Sydney and Canberra. In a fundamental sense, planning for social and economic change is determined by the size, growth and socioeconomic composition of populations. Accordingly, the scope of this profile is limited to those aspects of social and economic life in the region that form the basis of policy interest and intervention. These include the demographic structure and residence patterns of the regional population, labour force status, education, income, welfare, housing, and health status. For each of these categories, the aim was to identify and describe the main characteristics of the population and highlight outstanding features in the data. A further aim was to compare the socioeconomic status of Indigenous residents of the region with that of their non-Indigenous counterparts

Repeat prescribing of medications: a system-centred risk management model for primary care organisations

Rationale, aims and objectives: Reducing preventable harm from repeat medication prescriptions is a patient safety priority worldwide. In the United Kingdom, repeat prescriptions items issued has doubled in the last 20 years from 5.8 to 13.3 items per patient per annum. This has significant resource implications and consequences for avoidable patient harms. Consequently, we aimed to test a risk management model to identify, measure, and reduce repeat prescribing system risks in primary care. Methods: All 48 general medical practices in National Health Service (NHS) Lambeth Clinical Commissioning Group (an inner city area of south London in England) were recruited. Multiple interventions were implemented, including educational workshops, a web-based risk monitoring system, and external reviews of repeat prescribing system risks by clinicians. Data were collected via documentation reviews and interviews and subject to basic thematic and descriptive statistical analyses. Results: Across the 48 participating general practices, 62 unique repeat prescribing risks were identified on 505 occasions (eg, practices frequently experiencing difficulty interpreting medication changes on hospital discharge summaries), equating to a mean of 8.1 risks per practice (range: 1-33; SD = 7.13). Seven hundred sixty-seven system improvement actions were recommended across 96 categories (eg, alerting hospitals to illegible writing and delays with discharge summaries) with a mean of 15.6 actions per practice (range: 0-34; SD = 8.0). Conclusions: The risk management model tested uncovered important safety concerns and facilitated the development and communication of related improvement recommendations. System-wide information on hazardous repeat prescribing and how this could be mitigated is very limited. The approach reported may have potential to close this gap and improve the reliability of general practice systems and patient safety, which should be of high interest to primary care organisations internationally

Developing In-House Careers and Retaining Management Talent: What Hospitality Professionals Want from Their Jobs

One of the primary challenges the hospitality industry faces continues to be high levels of turnover. In this study, the authors examine turnover intentions of one of the most critical groups of employees: management staff. Using a sample of Cornell University School of Hotel Administration graduates from 1987 through 2002, the authors identify the job features that enhance managers\u27 commitment levels to their organizations and to the overall industry, as well as reduce their likelihood of leaving both. Results suggest that hospitality managers are taking charge of their careers. They are looking for challenging jobs that offer growth opportunities, as well as competent leadership and fair compensation. To the degree these job features are in place, hospitality managers\u27 commitment levels will rise. Managers\u27 commitment to performing challenging work especially reduces their likelihood of leaving their companies and the industry

Progress in the development of an 88-mm bore 10 Tn3Sn dipole magnet

A 10 T, 2-layer cos(&thetas;)-dipole model magnet with an 88 mm clear bore utilizing an advanced powder-in-tube Nb3Sn conductor is being developed for the LHC. A dedicated conductor development program has resulted in a well performing Rutherford cable containing strands that uniquely exhibit both an overall current density of 600 A/mm2 @ 11 T and filaments with a diameter of 20 ¿m. The resistance between crossing strands amounts to 30-70 ¿¿ by insertion of a stainless steel core. After being exposed to a transverse pressure of 200 MPa identical cables show negligible permanent degradation of the critical current. The mechanical support structure is further optimized in order to reduce the peak stress in the mid-plane to below 130 MPa at full excitation and to control the pre-stress build-up during system assembly. Prior to the manufacturing of the final coils a dummy 2-layer pole is wound, heat-treated at 675°C and vacuum resin impregnated. This paper presents the current status of the magnet development program and highlights in particular the successful conductor developmen

Conductor development for a wide bore 10 T Nb3Sn model dipole magnet

An 87.8 mm bore single aperture 10 T Nb3Sn model dipole magnet is under development as a next step in the realization of high-field Nb3Sn dipole magnets. The magnet is a 2 layer cos(&thetas;)-dipole model as an alternative for the proposed NbTi D1 beam separator magnets for the LHC. After completion of the general magnetic and mechanical design, all attention is focused on the manufacturing and cabling of a novel powder-in-tube Nb3Sn conductor. This Nb3Sn conductor is characterized by a high non-Cu Jc of 2680 A/mm2 at 10 T with an effective filament size of about 20 ¿m. Cabling should result in a Rutherford type of cable exhibiting a moderate Jc degradation due to the cabling process itself, a low transverse stress sensitivity and a controllable minimum value of Rc. The conductor development program is presented and the results are evaluated. Progress on the actual realization of the coils is briefly describe