3,975 research outputs found

    Future wave climate over the west-European shelf seas

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    In this paper, we investigate changes in the wave climate of the west-European shelf seas under global warming scenarios. In particular, climate change wind fields corresponding to the present (control) time-slice 1961–2000 and the future (scenario) time-slice 2061–2100 are used to drive a wave generation model to produce equivalent control and scenario wave climate. Yearly and seasonal statistics of the scenario wave climates are compared individually to the corresponding control wave climate to identify relative changes of statistical significance between present and future extreme and prevailing wave heights. Using global, regional and linked global–regional wind forcing over a set of nested computational domains, this paper further demonstrates the sensitivity of the results to the resolution and coverage of the forcing. It suggests that the use of combined forcing from linked global and regional climate models of typical resolution and coverage is a good option for the investigation of relative wave changes in the region of interest of this study. Coarse resolution global forcing alone leads to very similar results over regions that are highly exposed to the Atlantic Ocean. In contrast, fine resolution regional forcing alone is shown to be insufficient for exploring wave climate changes over the western European waters because of its limited coverage. Results obtained with the combined global–regional wind forcing showed some consistency between scenarios. In general, it was shown that mean and extreme wave heights will increase in the future only in winter and only in the southwest of UK and west of France, north of about 44–45° N. Otherwise, wave heights are projected to decrease, especially in summer. Nevertheless, this decrease is dominated by local wind waves whilst swell is found to increase. Only in spring do both swell and local wind waves decrease in average height

    Integrated Numerical Modelling System for Extreme Wave Events at the Wave Hub Site

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    This paper examines an extreme wave event which occurred during a storm at the Wave Hub site in 2012. The extreme wave of 9.57 m height was identified from a time series of the heave data collected by an Oceanor Seawatch Mini II Buoy deployed at the site. An energy density spectrum was derived from this time series and then used to drive a physical model, which represents the extreme wave at 1:20 scale in Plymouth University’s new COAST Lab. The NewWave technique was used to define the input to the physical model. The experiment is reproduced in a numerical wave tank using the fully nonlinear CFD library OpenFOAM® and the wave generation toolbox waves2Foam. Results are evaluated, and issues regarding the predictions of a numerical model that is driven by the NewWave input signal are discussed. This study sets the basis for further research in coupling field data, physical modelling and numerical modelling in a more efficient and balanced way. This will lead to the new approach of composite modelling that will be implemented in future work

    AROC Impairment Specific Report, Inpatient - Pathway 3 - Orthopaedic Replacements - Anywhere Hospital, January 2014 - December 2014

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    This is the third AROC Impairment Specific Report for Orthopaedic Replacements which compares YOUR FACILITY\u27s data to ALL AROC FACILITIES data (Australia and New Zealand). Each Impairment Specific Report is structured as a series of chapters. Each report will present an overall big picture chapter on the impairment followed by a chapter looking at FIM item scoring at YOUR FACILITY as compared to ALL AROC FACILITIES data by AN-SNAP class. An outcomes analysis chapter follows with an explanatory data chapter at the end

    AROC Impairment Specific Report, Inpatient - Pathway 3 - Spinal Cord Dysfunction - Anywhere Hospital, January 2014 - December 2014

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    This is the first AROC Impairment S pecific Report for spinal cord dysfunction which compares YOUR FACILITY\u27s data to data from SPECIALIST spinal cord injury services and data from NON SPECIALIST spinal cord injuries services (Australia and New Zeal and). Each Impairment Specific Report is structured as a series of chapters. Each report will present an overall big picture chapter on the impairment followed by a chapter looking at FIM item scoring at YOUR FACILITY. An outcomes analysis chapter follows with an explanatory data chapter at the end

    Radiochemical and analytical methods of analysis of radiological dispersal devices

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    The events on September 11th 2001 and subsequent attacks in America and around the world have brought a renewed interest in the nation's security including the concern over the use of a nuclear or a radiological dispersal device (RDD). Research has been done in two separate projects in order to help address some of these concerns. A research assistantship from Savannah River National Laboratory was granted in order to identify the unique characteristics of radioactive 192Ir materials (chapters 2-4). A method for the dissolving of the iridium with electrochemistry was developed and used for sample preparation for analysis. Mass spectrometry (ICP-MS) analysis was then used to identify and quantify impurities and isotope ratios in iridium from various locations across the country. The second research project has developed a series of nanoparticles for use as tagging and tracking explosives (chapters 5-7). The composition of the nanoparticles were created with lanthanides with varying composition to provide a unique signature that can be rapidly and precisely measured in the field via neutron activation analysis. The nanoparticles could be used as a real-time in the field method for tracking and identifying materials such as explosives in a post detonation scenario

    Frequency-Tunable Josephson Junction Resonator for Quantum Computing

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    We have fabricated and measured a high-Q Josephson junction resonator with a tunable resonance frequency. A dc magnetic flux allows the resonance frequency to be changed by over 10 %. Weak coupling to the environment allows a quality factor of \thicksim7000 when on average less than one photon is stored in the resonator. At large photon numbers, the nonlinearity of the Josephson junction creates two stable oscillation states. This resonator can be used as a tool for investigating the quality of Josephson junctions in qubits below the single photon limit, and can be used as a microwave qubit readout at high photon numbers.Comment: 3 pages, 5 figure

    Quantum nondemolition measurement of a nonclassical state of a massive object

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    While quantum mechanics exquisitely describes the behavior of microscopic systems, one ongoing challenge is to explore its applicability to systems of larger size and mass. Unfortunately, quantum states of increasingly macroscopic objects are more easily corrupted by unintentional measurements from the classical environment. Additionally, even the intentional measurements from the observer can further perturb the system. In optomechanics, coherent light fields serve as the intermediary between the fragile mechanical states and our inherently classical world by exerting radiation pressure forces and extracting mechanical information. Here we engineer a microwave cavity optomechanical system to stabilize a nonclassical steady-state of motion while independently, continuously, and nondestructively monitoring it. By coupling the motion of an aluminum membrane to two microwave cavities, we separately prepare and measure a squeezed state of motion. We demonstrate a quantum nondemolition (QND) measurement of sub-vacuum mechanical quadrature fluctuations. The techniques developed here have direct applications in the areas of quantum-enhanced sensing and quantum information processing, and could be further extended to more complex quantum states.Comment: 9 pages, 6 figure
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