South Wales

Carboniferous rocks in this region occur in a broadly east-west trending syncline, the core of which includes the South Wales and Pembrokeshire coalfields (Fig. 5.1). Tournaisian and Visean strata (Avon and Pembroke Limestone groups) represent deposition on a southward prograding carbonate ramp evolving into a carbonate shelf (Wright 1987), in a succession which shows similarities to that of the Bristol and Mendips areas (Chapter 6). The main outcrops, in south Pembrokeshire, Gower and the Vale of Glamorgan, occur along the southern periphery of the coalfields and are commonly affected by Variscan thrusting and folding. Thinner successions occur along what is termed the East Crop and North Crop of the South Wales Coalfield, where much of the Visean succession is absent due to sub-Namurian and intra-Visean unconformities. Namurian fluvio-deltaic deposits (Marros Group) flank the South Wales and Pembrokeshire coalfields. Much of the lower and middle Namurian succession is absent across the region, except in the west of the South Wales Coalfield where only small parts are absent beneath an intra-Namurian unconformity. Westphalian fluvio-lacustrine deposits (South Wales Coal Measures Group) form the South Wales and Pembrokeshire coalfields, located to the east and west of Carmarthen Bay, respectively. Westphalian to Stephanian Pennant alluvial facies (Warwickshire Group) occur in the core of the South Wales Coalfield syncline. Deposition of the South Wales Coal Measures and Warwickshire groups was probably laterally contiguous with those in the Bristol and Somerset coalfields (Chapter 6), but the Usk-Cowbridge High controlled and restricted sedimentation for much of the Carboniferous, with pre-Namurian uplift and erosion removing the Tournaisian and Visean succession. Later uplift is also believed to have caused attenuation of the Warwickshire Group in the east of the South Wales Coalfield. The lithostratigraphical nomenclature for the region is that of Waters et al. (2007; 2009)

Transport processes of particles in dilute suspensions in turbulent water flow—phase II

This work was concerned with an improved and more practical understanding of particle motion in a turbulent fluid field. It is felt that such an increased understanding has been achieved both in an analytical and in an experimental sense. Analytically, a theory simplified by the restrictive constraints of isotropy and Stokesian drag has been developed. Assumption of a reasonable particle energy spectrum allowed calculation of various statistical quantities important in the determination of the particle's turbulent motion. By such an analysis three characterizing parameters were found. Two describe inertial effects due to the particle's size and density. They were found to be of prime importance in the determination of the ratio of the particle's fluctuating velocity variance to that of the fluid. The crossing of the particle from one region of correlated fluid turbulence to another by virtue of its free fall velocity is described by the third parameters. This parameter was shown to be of particular importance in limiting the particle's velocity correlation. The two effects, of inertia and of free fall velocity, together act to determine dispersion. A well parameterized particle experiment was undertaken. Analysis of the particles' behavior in the turbulent flow gave a three dimensional characterization of their motion. In particular calculation of velocity variances, autocorrelations, and energy spectra were made. These measurements in conjunction with measurements on the turbulent fluid field allowed comparison between theory and experiment. Comparison of theoretical prediction to experimental observation showed good agreement provided the underlying assumptions inherent in the theoretical derivation were valid. Agreement suffered when these assumptions proved less valid. In particular non-Stokesian drag and anisotropic effects caused. disagreement between theory and experiment.U.S. Department of the InteriorU.S. Geological SurveyOpe

Transport processes of particles in non-dilute suspensions in turbulent water flow—phase I: Experimental measurements

Increased utilization of non-dilute, solid-fluid suspensions in transporting materials and in estimating the distribution of particles from atmospheric fallout, demands that the basic fluid-particle interactions be thoroughly understood. Our previous studies of such interactions were conducted on only dilute suspensions, whereas this study has been conducted in the same vertical flows but with solid spherical particle suspensions with concentrations, ɸ, from O to 10 percent by volume, a range of practical interest to sedimentation and erosion as well as in slurry pipelines. Detailed experimental results of the particle-fluid relative mean and rms velocities as well as particle dispersion were obtained for two particle densities and several ɸ values. Both particle types showed a rapid rise of both relative mean and rms velocities as ɸ increased to about 1-2 percent and fell off gradually for higher ɸ values. Dispersion followed a similar behavior. The higher free fall velocity particles exhibited larger rms velocities and increased dispersion from the lighter, lower free fall velocity particles. Analytical models of the ɸ-dependence showed good agreement with the data, suggesting their use in engineering predictions.U.S. Department of the InteriorU.S. Geological SurveyOpe

Optimising patient care in medical radiation services through health economics: an introduction

The role of health economics in optimising patient care in medical radiation clinical settings is of increasing importance in ensuring efficient and effective service delivery. This commentary introduces health economics to medical radiation professionals by outlining the main analysis types utilised, highlighted by examples in the literature. The purpose is to provide an over-arching framework and starting point for incorporating health economics into medical radiation research study protocols

Dietary glycaemic index and glycaemic load among Australian adults – results from the 2011–2012 Australian Health Survey

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Analysis and Measurement of Bubble Dynamics and Associated Flow Field in Subcooled Nucleate Boiling Flows

In recent years, subooled nucleate boiling (SNB) has attrcted expanding research interest owing to the emergence of axial offset anomaly (AOA) or crud-induced power shigt (CIPS) in many operating US PWRs, which is an unexpected deviation in the core axial power distribution from the predicted power curves. Research indicates that the formation of the crud, which directly leads to AOA phenomena, results from the presence of the subcooled nucleate boiling, and is especially realted to bubble motion occurring in the core region

Community Navigation as a Field of Practice: Reframing Service Delivery to Meet the Needs of Communities’ Marginalized Populations

Community navigators help individuals and families access local services and assistance through a combination of referrals and interpersonal support. The Denver Foundation launched the Basic Human Needs Navigator Learning Community in February 2014 to help navigators working with local organizations and community members practicing navigation independently improve their practice and identify similarities and differences in their approaches. This article discusses the multiyear, peer-learning project, including the general lessons the foundation learned about both navigation and the use of a learning-community approach to reach its field-building goals. Reports from participating organizations and community members over four years suggest the efficacy of both navigation as a model for addressing gaps in service provision and of the learning-community approach in driving early-stage field-building outcomes

Transport processes of particles in dilute suspensions in turbulent water flow—phase III

Understanding the basic mechanisms and predicting the behavior of particles suspended in turbulent fluid flow are essential to environmental conservation and to multiphase system design. Air and water pollution, sedimentation and erosion of river beds and coastal shorelines, and atmospheric fallout are some of the areas in which particle suspensions are of key importance. Detailed experimental measurements of dilute particle suspensions have been performed which examined the effects of particle size, shape and relative density on the statistical response of such particles in a turbulent fluid. Shape was found to be of minor importance for spheres, cubes and tetrahedrons. However, size was found to be important when the particle dimension was as large or larger than the fluid turbulence structure. Relative density influenced both free fall and inertial effects. An analytical model was developed which included these latter effects. It agrees well with observed particle dispersion measurements.U.S. Department of the InteriorU.S. Geological SurveyOpe

Transport processes of particles in dilute suspensions in turbulent water flow–phase I

Modifications to an existing experimental system have been made and have been demonstrated to provide the required resolution and variable parameterization necessary for a detailed study of dilute particle suspensions in a turbulent water flow. These modifications together with the reasons for their necessity are discussed. Linearization of non-Stokesian drag has been accomplished through the introduction of a diagonal tensor into the Stokes drag force equation. It was found that non-Stokesian effects tend to be of minor importance in the response of water borne particles.U.S. Department of the InteriorU.S. Geological SurveyOpe