Future Thames : applied geoscience for decision-making in London and the Thames Basin

The Thames Basin is the UK’s principal aquifer. It encompasses London, which is Europe’s largest megacity, and has an extensive coastal zone. It presents a unique conjunction of geological, hydrogeological, environmental, and socio-economic factors that are intrinsically linked by the effects of environmental change. The British Geological Survey (BGS) is responding to this challenge through its FutureThames initiative. FutureThames aims to initiate, facilitate and support interdisciplinary and collaborative geoscience research in an attempt to understand the effects of environmental change in the Thames Basin. Such collaboration will assist in providing ‘real world’ responses to different ‘what if’ scenarios, such as “What will happen to groundwater if a new housing estate is built here?” Or “How will sea-level rise affect my property?” Six key environmental challenges have been identified to provide a framework to focus our research activities in the region

Battlegrounds of environmental change

The Thames catchment encompasses one of Europe’s largest cities, the UK’s principal aquifer, an extensive zone of coastal interaction and much else. It presents a unique conjunction of geological, hydrogeological, environmental and socio-economic factors that are intrinsically linked by the effects of environmental change and the pressures of developmen

Economic Potential of Conservation Farming Annual Winter Forages for the Stocker Cattle Grazing Enterprise

The objective was to determine the expected net value of a no-till forage production and grazing system. Reduction in fuel and machinery costs offset the costs of herbicide application. The net value of the no-till system is $31 per acre, and is quite sensitive to relative differences in cattle performance.Farm Management, Land Economics/Use,

Down Time Terms and Information Used for Assessment of Equipment Reliability and Maintenance Performance

Reliability and maintenance data is important for predictive analysis related to equipment downtime in the oil and gas industry. For example, downtime data together with equipment reliability data is vital for improving system designs, for optimizing maintenance and in estimating the potential for hazardous events that could harm both people and the environment. The quality is largely influenced by the repair time taxonomy, such as the measures used to define downtime linked to equipment failures. However, although it is important to achieve high quality from maintenance operations as part of this picture, these often seem to receive less focus compared to reliability aspects. Literature and experiences from, e.g., the OREDA project suggest several challenging issues, which we discuss in this chapter, e.g., for the interpretation of “MTTR.” Another challenge relates to the duration of maintenance activities. For example, while performing corrective maintenance on an item, one could also be working on several other items while being on site. This provides an opening for different ways of recording the mobilization time and repair time, which may then influence the data used for predictive analysis. Some relevant examples are included to illustrate some of the challenges posed, and some remedial actions are proposed

Ahead of the game or behind the curve? (or, why building our confidence in models is essential)

Three-dimensional geological models provide geologists with a medium through which to convey their understanding of the subsurface. In the UK, geological modelling has recently been applied to several infrastructure projects, such as high speed railways and tunneling projects. Typically, models are used to indicate ground conditions at the initial planning stage of a project. For more proactive users, the model can also act as a medium through which to develop an evolving conceptual ground model as additional geological data and information is collected. The latter facilitates continuous improvement of geological knowledge and understanding and has the potential to enhance national geological understanding. Use of 3D data is becoming mainstream in the construction sector through the uptake of the building information model (BIM); that is a virtual 3D representation of structures that aids planning, design, scheduling, construction, maintenance and demolition. Unfortunately the application of 3D geological models appears to be lagging behind the uptake of BIM. Why is this? Are we reticent about deploying models with much less than the mm-scale accuracy afforded by BIM modelling? Or is geological uncertainty understood by professionals, and is it in fact, the geologists, who are reticent about deploying models widely, and hence are contributing to the lack of appreciation for what the models can offer to prospective users? This paper considers how we must proceed to improve confidence in 3D geological models; demonstrating the validity of the 3D medium, refining our approaches and recognising the errors may help us improve confidence in our ability to build 3D models, but moreover, perhaps it is the cultural barriers in particular, the geologist’s culture, that needs to change before we can convince the user community to embrace 3D geological modelling

Medication vs. radioablation for Graves' disease: how do they compare?

The benefits are similar; the risks vary. Treating Graves' disease initially with medication or radioablation (or surgery) produces comparable resolution of hyperthyroidism at 2 years (strength of recommendation [SOR]: B, a randomized clinical trial [RCT]). The goal of radioablation is lifelong hypothyroidism. While radioablation doesn't appear to increase the risk of neoplasia, "theoretical concerns" have led to the recommendation that it not be used for children younger than 5 years (SOR: C, expert opinion). Radioablation carries a higher risk of thyroid-associated ophthalmopathy (TAO) than medical therapy (SOR: B, an RCT and a lower-quality meta-analysis). Between 9% and 16% of patients are unable to tolerate medical therapy, mainly because of rash but also because of agranulocytosis (SOR: A, meta-analysis)

The application of porous media to simulate the upstream effects of gas turbine injector swirl vanes

Numerical simulations are an invaluable means of evaluating design solutions. This is especially true in the initial design phase of a project where several simulations may be required as part of an optimisation study. The design of aircraft gas turbine combustor external aerodynamics frequently calls upon the services of numerical methods to visualise the existing flow field, and develop architectures which improve the performance of the system. Many of these performance improvements are driven by the desire to reduce fuel burn and cut emissions lowering the environmental impact of aviation. The gas turbine combustion chamber is, however, reasonably complex geometrically and requires a high fidelity model to resolve small geometric details. The fuel injector is the most geometrically complex component, requiring around 20% of the mesh cells of the entire domain. This makes it expensive to model in terms of both requisite computational resource and run time. Most modern aircraft gas turbines utilise swirling flow fields to stabilise the flame front in the combustion liner. The swirl cone is generally generated using fixed angle vane rows within the injector. It is these small features that are responsible for the requisite high mesh cell count. This paper presents a numerical method for replacing the injector swirl vane passages with mathematically porous volumes which replicate the required pressure drop. Modelling using porous media is preferential to modelling the fully featured injector as it allows a significant reduction in the size of the computational domain and number of cells. Additionally the simplification makes the geometry easier to change, scale and re-mesh during development. This in turn allows significant time savings which serve ultimately to expedite the design process. This method has been rigorously tested through a range of approach conditions and flow conditions to ensure that it is robust enough for use in the design process. The loss in accuracy owing to the simplification has been demonstrated to be less than 4.4%, for all tested flow fields. This error is dependent on the flow conditions and is generally much less for passages fed with representative levels of upstream distortion