Perdido Key Beach nourishment project: Gulf Islands National Seashore 1991 annual report

This report is the second annual report in a continuing series documenting a field project within the Gulf Islands National Seashore at Perdido Key, Florida. The field project includes the monitoring of a number of physical parameters related to the evolution of the Perdido Key beach nourishment project. Approximately 4.1 million m3 of dredge spoil from Pensacola Pass were placed upon approximately 7 km of the Gulf of Mexico beaches of Perdido Key between November, 1989, and September, 1990. Beach profile data describing the evolution of the nourished beach are included, as well as wave, current, tide, wind, temperature, and rainfall data to describe the forces influencing the evolution. Data describing the sediment sizes throughout the project area are also included. A brief discussion of the data is included; a more detailed analysis and interpretation will be presented in the lead author's Ph.D. dissertation. (313 pp.

Cross-Shore Variation of Wind-Driven Flows on the Inner Shelf in Long Bay, South Carolina, United States

The cross-shore structure of subtidal flows on the inner shelf (7 to 12 m water depth) of Long Bay, South Carolina, a concave-shaped bay, is examined through the analysis of nearly 80 days of near-bed (1.7–2.2 m above bottom) current observations acquired during the spring and fall of 2001. In the spring and under northeastward winds (upwelling favorable) a two-layered flow was observed at depths greater than 10 m, while closer to the shore the currents were aligned with the wind. The two-layered flow is attributed to the presence of stratification, which has been observed under similar conditions in the South Atlantic Bight. When the wind stress was southwestward (downwelling favorable) and exceeded 0.1 N/m2, vertical mixing occurred, the two-layered flow pattern disappeared, and currents were directed alongshore with the wind at all sites and throughout the water column. In the fall, near-bed flows close to the shore (water depth \u3c7 m) were often reduced compared to or opposed those measured farther offshore under southwestward winds. A simplified analysis of the depth-averaged, alongshore momentum balance illustrates that the alongshore pressure gradient approached or exceeded the magnitude of the alongshore wind stress at the same time that the nearshore alongshore current opposed the wind stress and alongshore currents farther offshore. In addition, the analysis suggests that the wind stress is reduced closer to shore so that the alongshore pressure gradient is large enough to drive the flow against the wind

Wind Speed Dependence of Single-Site Wave-Height Retrievals from High-Frequency Radars

Wave-height observations derived from single-site high-frequency (HF) radar backscattered Doppler spectra are generally recognized to be less accurate than overlapping radar techniques but can provide significantly larger sampling regions. The larger available wave-sampling region may have important implications for observing system design. Comparison of HF radar–derived wave heights with acoustic Doppler profiler and buoy data revealed that the scale separation between the Bragg scattering waves and the peak energy-containing waves may contribute to errors in the single-site estimates in light-to-moderate winds. A wave-height correction factor was developed that explicitly considers this scale separation and eliminates the trend of increasing errors with increasing wind speed

Revisiting the 'Missing Middle' in English Sub-National Governance

In the light of the new Coalition Government’s proposed ‘rescaling’ of sub-national governance away from the regional level, it is an opportune time to re-consider the strength and weaknesses of the city or sub-regional approach to economic development and to search, once more, for the ‘missing middle’ in English Governance. In this context, the article initially assesses the case for city or sub regions as tiers of economic governance, before examining the lessons to be learnt from the experiences of the existing city regions in the North East of England. It argues that while contemporary plans to develop Local Enterprise Partnerships (LEPs) can be usefully considered within the context of the emerging city regional developments under the previous Labour Governments, a number of important challenges remain, particularly in relation to ensuring accountable structures of governance, a range of appropriate functions, adequate funding, and comprehensive coverage across a variety of sub-regional contexts. While the proposals of the new Government create the necessary ‘space’ to develop sub-regional bodies and offer genuine opportunities for both city and county LEPs, the scale of the sub-regional challenge should not be underestimated, particularly given the context of economic recession and major reductions in the public sector

Tidal stream energy site assessment via three-dimensional model and measurements

Author Posting. © The Author(s), 2012. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Applied Energy 102 (2013): 510-519, doi:10.1016/j.apenergy.2012.08.040.A methodology for assessment of the potential impacts of extraction of energy associated with astronomical tides is described and applied to a site on the Beaufort River in coastal South Carolina, U.S.A. Despite its name, the site features negligible freshwater inputs; like many in the region, it is a tidal estuary that resembles a river. A three-dimensional, numerical, hydrodynamic model was applied for a period exceeding a lunar month, allowing quantification of harmonic constituents of water level and velocity, and comparison to values derived from measurements, recorded at a location within the model domain. The measurement campaign included surveys of bathymetry and velocity fields during ebb and flood portions of a tidal cycle for model validation. Potential far-field impacts of a generic tidal energy conversion device were simulated by introducing an additional drag force in the model to enhance dissipation, resulting in 10-60% dissipation of the pre-existing kinetic power within a flow cross-section. The model reveals e ffects of the dissipation on water levels and velocities in adjacent areas, which are relatively small even at the 60% dissipation level. A method is presented to estimate the optimal vertical location for the energy conversion device and the potential power sacrificed by moving to a di fferent altitude.This work was supported by the U.S.Marine Corps, whose support is gratefully acknowledged

Recommendations to facilitate the ideal fit note: are they achievable in practice?

Background: Although the UK fit note has been broadly welcomed as a tool to facilitate return to work, difficulties and uncertainties have resulted in wide variation in its use. Agreement on what constitutes the ‘ideal’ fit note from the perspective of all stakeholders is needed to inform best practice. A recent Delphi study conducted by the authors reached consensus on 67 recommendations for best practice in fit note use for employed patients. However, such recommendations are not necessarily followed in practice. The purpose of this study was therefore to investigate the perceived achievability of implementing these Delphi recommendations with a further reference panel of stakeholders. Methods: Potential participants were identified by the research team and study steering group. These included representatives of employers, government departments, trades unions, patient organisations, general and medical practitioners and occupational health organisations who were believed to have the knowledge and experience to comment on the recommendations. The consensus Delphi statements were presented to the participants on-line. Participants were invited to comment on whether the recommendations were achievable, and what might hinder or facilitate their use in practice. Free text comments were combined with comments made in the Delphi study that referred to issues of feasibility or practicality. These were synthesised and analysed thematically. Results: Twelve individuals representing a range of stakeholder groups participated. Many of the recommendations were considered achievable, such as improved format and use of the electronic fit note, completion of all fields, better application and revision of guidance and education in fit note use. However a number of obstacles to implementation were identified. These included: legislation governing the fit note and GP contracts; the costs and complexity of IT systems and software; the limitations of the GP consultation; unclear roles and responsibilities for the funding and delivery of education, guidance and training for all stakeholders, and the evaluation of practice. Conclusions: This study demonstrated that although many recommendations for the ideal fit note are considered achievable, there are considerable financial, legal, organisational and professional obstacles to be overcome in order for the recommendations to be implemented successfully

Erosion characteristics and horizontal variability for small erosion depths in the Sacramento-San Joaquin River Delta, California, USA

Erodibility of cohesive sediment in the Sacramento-San Joaquin River Delta (Delta) was investigated with an erosion microcosm. Erosion depths in the Delta and in the microcosm were estimated to be about one floc diameter over a range of shear stresses and times comparable to half of a typical tidal cycle. Using the conventional assumption of horizontally homogeneous bed sediment, data from 27 of 34 microcosm experiments indicate that the erosion rate coefficient increased as eroded mass increased, contrary to theory. We believe that small erosion depths, erosion rate coefficient deviation from theory, and visual observation of horizontally varying biota and texture at the sediment surface indicate that erosion cannot solely be a function of depth but must also vary horizontally. We test this hypothesis by developing a simple numerical model that includes horizontal heterogeneity, use it to develop an artificial time series of suspended-sediment concentration (SSC) in an erosion microcosm, then analyze that time series assuming horizontal homogeneity. A shear vane was used to estimate that the horizontal standard deviation of critical shear stress was about 30% of the mean value at a site in the Delta. The numerical model of the erosion microcosm included a normal distribution of initial critical shear stress, a linear increase in critical shear stress with eroded mass, an exponential decrease of erosion rate coefficient with eroded mass, and a stepped increase in applied shear stress. The maximum SSC for each step increased gradually, thus confounding identification of a single well-defined critical shear stress as encountered with the empirical data. Analysis of the artificial SSC time series with the assumption of a homogeneous bed reproduced the original profile of critical shear stress, but the erosion rate coefficient increased with eroded mass, similar to the empirical data. Thus, the numerical experiment confirms the small-depth erosion hypothesis. A linear model of critical shear stress and eroded mass is proposed to simulate small-depth erosion, assuming that the applied and critical shear stresses quickly reach equilibrium

Understanding social housing tenants' rent payment behaviour: evidence from Great Britain

The Governments of many Western countries have been increasingly concerned with influencing the behaviour of their citizens. One way that they have done this is by giving them new responsibilities. In the UK, an example of this is 'direct payment' which sees social housing tenants in receipt of income-related housing allowance ('Housing Benefit') assuming responsibility for paying their rent. Drawing on a comprehensive data-set generated by the direct payment pilot evaluation, this paper examines tenants' rent payment behaviour. It draws on a conceptual framework from behavioural science - COM-B - which presents behaviour (B) as a result of the interaction between the capabilities (C) of subjects, the opportunity (O) they have to enact behaviours, and their motivation (M). Tenants' behaviour was influenced by all elements of the model, with it being more than just a consequence of opportunity, and their financial circumstances, specifically, although it was the most important one

Staying at work with back pain: patients' experiences of work-related help received from GPs and other clinicians. A qualitative study

<p>Abstract</p> <p>Background</p> <p>Low back pain commonly affects work ability, but little is known about the work-related help and advice that patients receive from GPs and other clinicians. The purpose of this study was to explore the experiences of employed people with back pain and their perceptions of how GPs and other clinicians have addressed their work difficulties.</p> <p>Methods</p> <p>A qualitative approach with thematic analysis was used. Individual interviews were carried out with twenty-five employed patients who had been referred for back pain rehabilitation. All had expressed concern about their ability to work due to low back pain.</p> <p>Results</p> <p>The perception of the participants was that GPs and other clinicians had provided little or no work-focused guidance and support and rarely communicated with employers. Sickness certification was the main method that GPs used to manage participants' work problems. Few had received assistance with temporary modifications and many participants had remained in work despite the advice they had received. There was little expectation of what GPs and other clinicians could offer to address work issues.</p> <p>Conclusions</p> <p>These findings question the ability of GPs and other clinicians to provide work-focused support and advice to patients with low back pain. Future research is recommended to explore how the workplace problems of patients can be best addressed by health professionals.</p