Fully submerged composite cryogenic testing

New methods for marine salvage and decommissioning of structures in the open sea are continually being sought in order to improve control and lower operational costs [1]. The concept design of a lightweight, cryogenic, marine, heavy lift, buoyancy system has been investigated [2]. The objective is to be able to raise or lower high mass objects controlled solely from a surface support vessel. The overall design concept and associated system development issues have been discussed previously. A number of the sub-systems in one complete buoyancy system involve considerable design and development, these include: structural design of the buoyancy chamber, mechanical systems to control and connection to the lift device, the cryogenic system itself and overall process control systems. The main area of concern in the design process is the composite cryogenic Dewar. This is required to operate not only at temperatures as low as -196oC but also to withstand pressure differences exceeding 35bar. As such the composite materials have to perform in a very aggressive environment. This work details a method for fully submersed composite cryogenic testing in order to qualify the materials for use in the Dewar of the buoyancy system

Development of high performance composite bend-twist coupled blades for a horizontal axis tidal turbine

Development of a design methodology for a composite, bend-twist coupled, tidal turbine blade has been undertaken. Numerical modelling was used to predict the response of the main structural member for the adaptive blade. An experimental method for validation is described. The analysis indicates a non-linear blade twist response

Use of cryogenic buoyancy systems for controlled removal of heavy objects from the seabed

The concept design of a lightweight cryogenic marine heavy lift buoyancy system has been investigated. The approach makes use of a novel cryogenic system for provision of buoyancy within the ocean environment. The objective is to be able to lift or lower large displacement objects under full remote control. The nature of subsea lifting and lowering operations requires a high degree of precise control for operational safety, reasons and to preserve the structural integrity of the load. The lift operation occurs in two phases: Development of lift to overcome seabed suction, and then rapid reduction of buoyancy to maintain a controlled ascent. Descent involves controlled release of the buoyancy. The proposed buoyancy system consists of a buoyancy chamber and an integral cryogenic gas generation unit. The application of an on-board gas generation unit allows the removal of the engineering challenges associated with use of compressors and the concomitant complex manifold of connecting umbilical pipe work. It provides for a fully remote system completely eliminating all risk associated with extensive physical surface to subsea connection throughout the entire lift operation. The opening stages of the project work include the development of a system that will operate efficiently and effectively to a depth of 350m. An initial general arrangement for the buoyancy system has been developed. A number of these systems involve considerable design and development, these include: structural design of the buoyancy chamber, mechanical systems to control and connection to the lift device, the cryogenic system itself and overall process control systems. As part of the design process for such an arrangement, numerical simulation of the complete system has been undertaken in order to develop mechanical, cryogenic and process control systems efficiently and effectively. This system simulation has been developed using Matlab Simulink. This paper considers the overall design concept and associated system development issues. These are illustrated through use of the time accurate simulation of alternative design configurations that confirm the viability of the concept. A main conclusion is that minimisation of the dry weight of the system is critical to cost-effective operation of the project

Development of a floating tidal energy system suitable for use in shallow water

A proposal is made for the use of a traditional streamwaterwheel suspended between two floating catamaranNPL series demi-hulls as means of generating electricalpower. Two prototype devices, of lengths 1.6m and 4.5m,have been developed, constructed and tested. It was foundthat the concept is sound although greater investment isrequired with regards to the materials and bothhydrodynamic and aerodynamic design of the waterwheelto ensure an economically viable system. The workpresented concentrates on practical aspects associated withdesign, construction and trial testing in Southampton waterof the 4.5m prototype. The relatively low cost, ease ofdeployment, and the fact that conventional boat mooringsystems are effective, combine to make this an attractivealternative energy solution for remote communities

Grape Expectations: A Survey of British Vineyard Land Management Practices From an Environmental Perspective

Traditional vineyard landscapes are generally intensively managed with heavy reliance on synthetic pesticides. Viticulture is one of the fastest-growing sectors of English agriculture and information on land management is essential to secure a sustainable future. We surveyed viticulturists to ascertain vineyard pest presence, pest control, inter-row ground cover and wildflower use. The majority of viticulturists reported the presence of vineyard pests and relied heavily on pesticides, with 74% using synthetic pest control, 40% using herbicides, 40% using fungicides. Inter-row, 66% of vineyards have grass-only cover and frequent summer mowing, with only 6% sowing wildflowers. However, 60% use natural pest control, 80% reported existence of wildflowers in headlands, and 29% mentioned reduced mowing. We discuss spontaneous and sown wildflowers and benefits for biodiversity, integrated pest management and the commonly perceived barriers to adaptation. We conclude there is huge variation in management styles and more evidence-based environmental advice for viticulturists is needed

Consensus virtual screening approaches to predict protein ligands

In order to exploit the advantages of receptor-based virtual screening, namely time/cost saving and specificity, it is important to rely on algorithms that predict a high number of active ligands at the top ranks of a small molecule database. Towards that goal consensus methods combining the results of several docking algorithms were developed and compared against the individual algorithms. Furthermore, a recently proposed rescoring method based on drug efficiency indices was evaluated. Among AutoDock Vina 1.0, AutoDock 4.2 and GemDock, AutoDock Vina was the best performing single method in predicting high affinity ligands from a database of known ligands and decoys. The rescoring of predicted binding energies with the water/butanol partition coeffcient did not lead to an improvement averaged over all receptor targets. Various consensus algorithms were investigated and a simple combination of AutoDock and AutoDock Vina results gave the most consistent performance that showed early enrichment of known ligands for all receptor targets investigated. In case a number ligands is known for a specific target, every method proposed in this study should be evaluated

The Change in Test Cricket Performance Following the Introduction of T20 Cricket: Implications for Tactical Strategy

International cricket has evolved from predominantly Test cricket, to shorter formats of competition. With the high player overlap between formats, the introduction of Twenty20 (T20) cricket is proposed to have influenced Test cricket and therefore the tactical strategies coaches and players should attempt to implement. The aim of this study was to identify the change in specific Test cricket performance metrics following the introduction of T20 cricket across a 20-year period (2000-2020). A total of 667 matches involving the top eight International Cricket Council (ICC) Test-cricket nations were analyzed. Overall, the introduction of T20 cricket has been associated with a change in the way in which Test cricket is currently played. Results identified significantly ( p < 0.001) more runs being scored by sixes and less by fours. A significant (17.4%; p < 0.001) decrease was also present in the percentage of Test matches ending in draws (23.5% in 2000 to 6.4% in 2020). Run rates increased for five teams (India, New Zealand, Pakistan, South Africa, and Sri Lanka), remained constant for one team (West Indies), and decreased for two teams (Australia, England) across the entire period studied. However, there was no change in the number of days Test matches lasted, with the average number of days continuing to last into day five (4.5 decreasing to 4.3). Findings highlight that improving the ability to strike a greater number of sixes, increase the overall run rate, and facilitate strike rotation when batting to be a focus for coaches and players alike. Future studies should ascertain whether the introduction of T20 has had an effect on One Day International (ODI) performance variables while further considering the impact of home advantage and team quality, to facilitate enhanced tactical and strategic decision-making