394 research outputs found
Adapting Multi-touch Systems to Capitalise on Different Display Shapes
The use of multi-touch interaction has become more widespread. With this increase of use, the change in input technique has prompted developers to reconsider other elements of typical computer design such as the shape of the display. There is an emerging need for software to be capable of functioning correctly with different display shapes. This research asked: ‘What must be considered when designing multi-touch software for use on different shaped displays?’ The results of two structured literature surveys highlighted the lack of support for multi-touch software to utilise more than one display shape. From a prototype system, observations on the issues of using different display shapes were made. An evaluation framework to judge potential solutions to these issues in multi-touch software was produced and employed. Solutions highlighted as being suitable were implemented into existing multi-touch software. A structured evaluation was then used to determine the success of the design and implementation of the solutions. The hypothesis
of the evaluation stated that the implemented solutions would allow the applications to be used with a range of different display shapes in such a way that did not leave visual content items unfit for purpose. The majority of the results conformed to this hypothesis despite minor deviations from the designs of solutions being discovered in the implementation. This work highlights how developers, when producing multi-touch software intended for more than one display shape, must consider the issue of visual content
items being occluded. Developers must produce, or identify, solutions to resolve this issue which conform to the criteria outlined in this research. This research shows that it is possible for multi-touch software to be made display shape independent
What factors influenced the choice of medical specialty for doctors surveyed in the final year at medical school and again having entered their specialty training destination?
CFD Prediction of Turbulent Flow on an Experimental Tidal Stream Turbine using RANS modelling
The Effects of Astaxanthin on Cognitive Function and Neurodegeneration in Humans: A Critical Review
Oxidative stress is a key contributing factor in neurodegeneration, cognitive ageing, cognitive decline, and diminished cognitive longevity. Issues stemming from oxidative stress both in relation to cognition and other areas, such as inflammation, skin health, eye health, and general recovery, have been shown to benefit greatly from antioxidant use. Astaxanthin is a potent antioxidant, which has been outlined to be beneficial for cognitive function both in vitro and in vivo. Given the aforementioned promising effects, research into astaxanthin with a focus on cognitive function has recently been extended to human tissue and human populations. The present critical review explores the effects of astaxanthin on cognitive function and neurodegeneration within human populations and samples with the aim of deciphering the merit and credibility of the research findings and subsequently their potential as a basis for therapeutic use. Implications, limitations, and areas for future research development are also discussed. Key findings include the positive impacts of astaxanthin in relation to improving cognitive function, facilitating neuroprotection, and slowing neurodegeneration within given contexts
Constructive interference effects for tidal turbine arrays
The performance benefits of deploying tidal turbines in close side-by-side proximity to exploit constructive interference effects are demonstrated experimentally using two 1.2 m diameter turbines. The turbines are arrayed side-by-side at 1/4 diameter tip-to-tip spacing, and their performance compared with that of a single rotor. Tests were completed in the 25 m diameter, 2 m deep wave and current FloWave Ocean Energy Research facility. A detailed assessment of inflow conditions at different control points is used to understand the impact that rotors, designed for high blockage conditions, have on the approach flow. After accounting for global blockage, a 10.8 % uplift in the twin-turbine-averaged power coefficient, relative to that for a single turbine, is found for the turbine design speed, at the expense of a 5.2 % increase in thrust coefficient and 3.1 % increase in tip-speed-ratio. Flowfield mapping demonstrated flow effects at array and device scale including array bypass flows and jetting between turbines. Azimuthal variation of blade root flapwise and edgewise bending moments show that the turbines interact in a beneficial manner, with additional and sustained loading peaks as the blades pass in close proximity to the neighbouring rotor. Peak performance for the twin turbines occurred at a higher tip-speed-ratio than for the single turbine, which is consistent with the twin turbines exerting a higher thrust on the flow to achieve maximum power. The twin turbine performance variation with tip-speed-ratio is found to be more gradual than for the single turbine. Using differential rotor speed control we observe that array performance is robust to small differences in neighbouring rotor operating point. Through these experiments we demonstrate that there is a substantial, achievable performance benefit from closely arraying turbines for side-by-side operation and designing them for constructive interference
Dangers of Polypharmacy
Although the definition of polypharmacy has evolved over time, it has been and remains to be an issue in healthcare. With the prevalence of polypharmacy increasing, those in the health care field must remain vigilant of the adverse effects of medications and work to coordinate care and maintain appropriate prescribing practices. Here we present a clinical vignette that describes an encounter of a patient on multiple medications and the individual, provider, and systems‐level issues that may have contributed to an adverse event resulting in a hospital stay. We will discuss the definition of polypharmacy, review the prevalence and economic implications of drug prescription practices, and examine the consequences and complications of polypharmacy in a number of different patient populations. We will discuss a number of scenarios involving polypharmacy that lead to medication errors, decreased quality of life, and patient harm, and then review evidence‐based methods of interventions aimed at reducing the prevalence of polypharmacy and its associated complications
From Cooperation to Competition: The Future of U.S.-Russian Relations
https://press.armywarcollege.edu/monographs/1928/thumbnail.jp
Power variability of tidal-stream energy and implications for electricity supply
Temporal variability in renewable energy presents a major challenge for electrical grid systems. Tides are considered predictable due to their regular periodicity; however, the persistence and quality of tidal-stream generated electricity is unknown. This paper is the first study that attempts to address this knowledge gap through direct measurements of rotor-shaft power and shore-side voltage from a 1 MW, rated at grid-connection, tidal turbine (Orkney Islands, UK). Tidal asymmetry in turbulence parameters, flow speed and power variability were observed. Variability in the power at 0.5 Hz, associated with the 10-min running mean, was low (standard deviation 10–12% of rated power), with lower variability associated with higher flow speed and reduced turbulence intensity. Variability of shore-side measured voltage was well within acceptable levels (∼0.3% at 0.5 Hz). Variability in turbine power had <1% difference in energy yield calculation, even with a skewed power variability distribution. Finally, using a “t-location” distribution of observed fine-scale power variability, in combination with an idealised power curve, a synthetic power variability model reliably downscaled 30 min tidal velocity simulations to power at 0.5 Hz (R2 = 85% and ∼14% error). Therefore, the predictability and quality of tidal-stream energy may be undervalued in a future, high-penetration renewable energy, electricity grid
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Synthesis of Satellite (MODIS), Aircraft (ICARTT), and Surface (IMPROVE, EPA-AQS, AERONET) Aerosol Observations over Eastern North America to Improve MODIS Aerosol Retrievals and Constrain Surface Aerosol Concentrations and Sources
We use an ensemble of satellite (MODIS), aircraft, and ground-based aerosol observations during the ICARTT field campaign over eastern North America in summer 2004 to (1) examine the consistency between different aerosol measurements, (2) evaluate a new retrieval of aerosol optical depths (AODs) and inferred surface aerosol concentrations from the MODIS satellite instrument, and (3) apply this collective information to improve our understanding of aerosol sources. The GEOS-Chem global chemical transport model (CTM) provides a transfer platform between the different data sets, allowing us to evaluate the consistency between different aerosol parameters observed at different times and locations. We use an improved MODIS AOD retrieval based on locally derived visible surface reflectances and aerosol properties calculated from GEOS-Chem. Use of GEOS-Chem aerosol optical properties in the MODIS retrieval not only results in an improved AOD product but also allows quantitative evaluation of model aerosol mass from the comparison of simulated and observed AODs. The aircraft measurements show narrower aerosol size distributions than those usually assumed in models, and this has important implications for AOD retrievals. Our MODIS AOD retrieval compares well to the ground-based AERONET data (R = 0.84, slope = 1.02), significantly improving on the MODIS c005 operational product. Inference of surface from our MODIS AOD retrieval shows good correlation to the EPA-AQS data (R = 0.78) but a high regression slope (slope = 1.48). The high slope is seen in all AOD-inferred concentrations (AERONET: slope = 2.04; MODIS c005: slope = 1.51) and could reflect a clear-sky bias in the AOD observations. The ensemble of MODIS, aircraft, and surface data are consistent in pointing to a model overestimate of sulfate in the mid-Atlantic and an underestimate of organic and dust aerosol in the southeastern United States. The sulfate overestimate could reflect an excessive contribution from aqueous-phase production in clouds, while the organic carbon underestimate could possibly be resolved by a new secondary pathway involving dicarbonyls.Engineering and Applied Science
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