Absorbing wave makers and wide tanks

Experiments aimed at generating power from sea waves used models which sometimes reflected waves back to the wave-maker. The difficulty was avoided by changing the wave-maker control system so that it could absorb reflections. A wide tank using a bank of absorbing wave-makers is being used to test more advanced models in seas of controlled angular spread. A crude measure of crest-length can be obtained from measurement of the correlation coefficients between wave-gauges at different separations

Power conversion systems for Ducks

This paper tries to define the problems of power conversion for a wave power device . It presents a little of the background theory; it discusses design principles, existing components and modifications to them; it tries to identify the main practical difficulties. Finally, it describes four possible solutions

Light from the Face of the Deep?

Description of the development of the Duck in the University of Edinburgh Bulletin

Bending moments in long spines

While it is unusual to test tank-models with controlled, variable elasticity there are several reasons why we believe that it is im-portant to exert the large effort required. 1. The convenient model-building materials are much too stiff to represent the proper behaviour of concrete and steel at full scale. 2. We believe that, although the close-packed, crest-spanning ter-minator configuration is the best possible arrangement for a wave-energy device, it is not economic to resist bending moments great-er than those which would occur at the power limit. This means that non-destructive yielding to bigger waves must be achieved. This will not only save money on the spine structure but will also produce dramatic reductions in mooring forces. 3. Work in the narrow tank had shown that the correct control of a duck mounting could produce large improvements in duck perfor-mance, doubling the efficiency in waves twenty-five duck diameters in length. We had also discovered that the best values of mounting stiffness were low, less than those that would be provided by post-tensioned concrete at full scale, and that the mounting move-ment could itself be a useful power-generating mechanism. Further-more the hardware needed to provide non-destructive yielding needed very little modification to provide intelligent control and the extra generating capability. We realised that the software require-ments would be formidable - well beyond our present knowledge. But we were confident that the existence of a controlled model would, as so often before, stimulate theoretical work. Furthermore we were quite certain that the progress of computer technology be-tween now and the date of the return of energy shortage would be so enormous that any level of control sophistication could be safe-ly assumed to be available at virtually zero cost. On many occa-sions it has seemed that this view was not shared by the civil and marine engineers who assess our progress. The work reported in this volume covers the measurements of bending moments and joint angles as a function of sea conditions, model lengths and stiffness, for circular spine sections without ducks. Other volumes will contain the observations of shear, axial, torsion and mooring forces, for spines with various appendages

Updated report on the Edinburgh - Laing wave energy device (The Duck)

John Laing Limited have been associated with Stephen Salter, of Edinburgh University, since the late autumn of 1978. In May 1981, at the request of ETSU, a proposal was submitted to The Wave Energy Steering Committee for updating the 1979 report. This presentation led to an Instruction to Proceed being issued by the Department of Energy in August 1981

Revolutionizing Alzheimer\u27s disease and clinical trials through biomarkers

AbstractThe Alzheimer's Association's Research Roundtable met in May 2014 to explore recent progress in developing biomarkers to improve understanding of disease pathogenesis and expedite drug development. Although existing biomarkers have proved extremely useful for enrichment of subjects in clinical trials, there is a clear need to develop novel biomarkers that are minimally invasive and that more broadly characterize underlying pathogenic mechanisms, including neurodegeneration, neuroinflammation, and synaptic dysfunction. These may include blood-based assays and new neuropsychological testing protocols, as well as novel ligands for positron emission tomography imaging, and advanced magnetic resonance imaging methodologies. In addition, there is a need for biomarkers that can serve as theragnostic markers of response to treatment. Standardization remains a challenge, although international consortia have made substantial progress in this area and provide lessons for future standardization efforts

Acupuncture for chronic neck pain: a pilot for a randomised controlled trial

Background: Acupuncture is increasingly being used for many conditions including chronic neck pain. However the evidence remains inconclusive, indicating the need for further well-designed research. The aim of this study was to conduct a pilot randomised controlled parallel arm trial, to establish key features required for the design and implementation of a large-scale trial on acupuncture for chronic neck pain. Methods: Patients whose GPs had diagnosed neck pain were recruited from one general practice, and randomised to receive usual GP care only, or acupuncture ( up to 10 treatments over 3 months) as an adjunctive treatment to usual GP care. The primary outcome measure was the Northwick Park Neck Pain Questionnaire (NPQ) at 3 months. The primary analysis was to determine the sample size for the full scale study. Results: Of the 227 patients with neck pain identified from the GP database, 28 (12.3%) consenting patients were eligible to participate in the pilot and 24 (10.5%) were recruited to the trial. Ten patients were randomised to acupuncture, receiving an average of eight treatments from one of four acupuncturists, and 14 were randomised to usual GP care alone. The sample size for the full scale trial was calculated from a clinically meaningful difference of 5% on the NPQ and, from this pilot, an adjusted standard deviation of 15.3%. Assuming 90% power at the 5% significance level, a sample size of 229 would be required in each arm in a large-scale trial when allowing for a loss to follow-up rate of 14%. In order to achieve this sample, one would need to identify patients from databases of GP practices with a total population of 230,000 patients, or approximately 15 GP practices roughly equal in size to the one involved in this study (i.e. 15,694 patients). Conclusion: This pilot study has allowed a number of recommendations to be made to facilitate the design of a large-scale trial, which in turn will help to clarify the existing evidence base on acupuncture for neck pain

The wide tank

Our aim was to construct a tank with complete control of directional distribution of energy as well as spectral shape. This control is important for several types of wave power device but it is of critical importance for the design of the backbone of a duck string