1,258 research outputs found
First observations of confined fast ions in MAST Upgrade with an upgraded neutron camera
Spherical tokamaks are key to the successful design of operating scenarios of future fusion reactors in the areas of divertor physics, neutral beam current drive and fast ion physics. MAST Upgrade, which has successfully concluded its first experimental campaign, was specifically designed to address the role of the radial gradient of the fast ion distribution in driving the excitation of magneto-hydrodynamic (MHD) instabilities, such as toroidal Alfvén eigenmodes, fish-bones and long-lived mode, thanks to its two tangential neutral beam injection systems, one on the equatorial plane and one that is vertically shifted 65 cm above the equatorial plane. To study the fast ion dynamics in the presence of such instabilities, as well as of sawteeth and neo-classical tearing modes, several fast ion diagnostics were upgraded and new ones added. Among them, the MAST prototype neutron camera (NC) has been upgraded to six, equatorial sight-lines. The first observations of the confined fast ion behavior with the upgraded NC in a wide range of plasma scenarios characterized by on-axis and/or off-axis heating and different MHD instabilities are presented here. The observations presented in this study confirm previous results on MAST but with a higher level of detail and highlight new physics observations unique to the MAST Upgrade. The results presented here confirm the improved performance of the NC Upgrade, which thus becomes one of the key elements, in combination with the rich set of fast ion diagnostics available on the MAST Upgrade, for a more constrained modeling of the fast ion dynamics in fusion reactor relevant scenarios
Vibrotactile pedals : provision of haptic feedback to support economical driving
The use of haptic feedback is currently an underused modality in the driving environment, especially with respect to vehicle manufacturers. This exploratory study evaluates the effects of a vibrotactile (or haptic) accelerator pedal on car driving performance and perceived workload using a driving simulator. A stimulus was triggered when the driver exceeded a 50% throttle threshold, past which is deemed excessive for economical driving. Results showed significant decreases in mean acceleration values, and maximum and excess throttle use when the haptic pedal was active as compared to a baseline condition. As well as the positive changes to driver behaviour, subjective workload decreased when driving with the haptic pedal as compared to when drivers were simply asked to drive economically. The literature suggests that the haptic processing channel offers a largely untapped resource in the driving environment, and could provide information without overloading the other attentional resource pools used in driving
Microwave study of quantum n-disk scattering
We describe a wave-mechanical implementation of classically chaotic n-disk
scattering based on thin 2-D microwave cavities. Two, three, and four-disk
scattering are investigated in detail. The experiments, which are able to probe
the stationary Green's function of the system, yield both frequencies and
widths of the low-lying quantum resonances. The observed spectra are found to
be in good agreement with calculations based on semiclassical periodic orbit
theory. Wave-vector autocorrelation functions are analyzed for various
scattering geometries, the small wave-vector behavior allowing one to extract
the escape rate from the quantum repeller. Quantitative agreement is found with
the value predicted from classical scattering theory. For intermediate
energies, non-universal oscillations are detected in the autocorrelation
function, reflecting the presence of periodic orbits.Comment: 13 pages, 8 eps figures include
Mass-Balance-Consistent Geological Stock Accounting: a New Approach toward Sustainable Management of Mineral Resources
Global resource extraction raises concerns about environmental pressures and the security of mineral supply. Strategies to address these concerns depend on robust information on natural resource endowments, and on suitable methods to monitor and model their changes over time. However, current mineral resources and reserves reporting and accounting workflows are poorly suited for addressing mineral depletion or answering questions about the long-term sustainable supply. Our integrative review finds that the lack of a robust theoretical concept and framework for mass-balance (MB)-consistent geological stock accounting hinders systematic industry-government data integration, resource governance, and strategy development. We evaluate the existing literature on geological stock accounting, identify shortcomings of current monitoring of mine production, and outline a conceptual framework for MB-consistent system integration based on material flow analysis (MFA). Our synthesis shows that recent developments in Earth observation, geoinformation management, and sustainability reporting act as catalysts that make MB-consistent geological stock accounting increasingly feasible. We propose first steps for its implementation and anticipate that our perspective as “resource realists” will facilitate the integration of geological and anthropogenic material systems, help secure future mineral supply, and support the global sustainability transition
Effective connectivity reveals strategy differences in an expert calculator
Mathematical reasoning is a core component of cognition and the study of experts defines the upper limits of human cognitive abilities, which is why we are fascinated by peak performers, such as chess masters and mental calculators. Here, we investigated the neural bases of calendrical skills, i.e. the ability to rapidly identify the weekday of a particular date, in a gifted mental calculator who does not fall in the autistic spectrum, using functional MRI. Graph-based mapping of effective connectivity, but not univariate analysis, revealed distinct anatomical location of “cortical hubs” supporting the processing of well-practiced close dates and less-practiced remote dates: the former engaged predominantly occipital and medial temporal areas, whereas the latter were associated mainly with prefrontal, orbitofrontal and anterior cingulate connectivity. These results point to the effect of extensive practice on the development of expertise and long term working memory, and demonstrate the role of frontal networks in supporting performance on less practiced calculations, which incur additional processing demands. Through the example of calendrical skills, our results demonstrate that the ability to perform complex calculations is initially supported by extensive attentional and strategic resources, which, as expertise develops, are gradually replaced by access to long term working memory for familiar material
Translating and transforming care: people with brain injury and caregivers filling in a disability claim form
This article examines how the Disability Living Allowance claim form, used in the United Kingdom to allocate £13 billion of disability benefits, translates and transforms disability and care. Twenty-two people with acquired brain injury and their main informal caregivers (n = 44) were video-recorded filling in the disability claim form. Participants disagreed on 26% of the questions, revealing two types of problems. Translation problems arose as participants struggled to provide categorical responses to ambiguous questions and were unable to report contextual variability in care needs or divergences of perception. Transformation problems arose as participants resisted the way in which the form positioned them, forcing them to conceptualize their relationship in terms of dependency and burden. The disability claim form co-opts claimants to translate care and disability into bureaucratically predefined categories, and it transforms the care relationship that it purports to document
Apprenticeship Training in Germany – Investment or Productivity Driven?
The German dual apprenticeship system came under pressure in recent years because enterprises were not willing to offer a sufficient number of apprenticeship positions. A frequently made argument is that the gap could be closed if more firms would be willing to incur net costs during the training period. This paper investigates for the first time whether German enterprises on average indeed incur net costs during the apprenticeship period, i.e. if the impact of an increase in the share of apprentices on contemporary profits is negative. The paper uses the representative linked employer-employee panel data of the IAB (LIAB) and takes into account possible endogeneity of training intensity and unobserved heterogeneity in the profit estimation by employing panel system GMM methods. An increase in the share of apprentices has no effect on profits. This can be interpreted as a first indication that most establishments in Germany do not invest more in apprentices than their productivity effects during the apprenticeship period
Developing cartoons for long-term condition self-management information
Background: Advocating the need to adopt more self-management policies has brought with it an increasing demand for information about living with and making decisions about long-term conditions, with a significant potential for using cartoons. However, the purposeful use of cartoons is notably absent in many areas of health care as is evidence of their acceptability to patients and lay others. This paper outlines the process used to develop and evaluate cartoons and their acceptability for a series of self-management guidebooks for people with inflammatory bowel disease, irritable bowel syndrome, diabetes, chronic obstructive pulmonary disease and chronic kidney disease (CKD).
Methods: Principles for a process to develop information and cartoons were developed. Cartoon topics were created using qualitative research methods to obtain lay views and experiences. The CKD guidebook was used to provide a detailed exemplar of the process. Focus group and trial participants were recruited from primary care CKD registers. The book was part of a trial intervention; selected participants evaluated the cartoons during in-depth interviews which incorporated think-aloud methods.
Results: In general, the cartoons developed by this process depict patient experiences, common situations, daily management dilemmas, making decisions and choices and the uncertainties associated with conditions. CKD cartoons were developed following two focus groups around the themes of getting a diagnosis; understanding the problem; feeling that facts were being withheld; and setting priorities. Think-aloud interviews with 27 trial participants found the CKD cartoons invoked amusement, recognition and reflection but were sometimes difficult to interpret.
Conclusion: Humour is frequently utilised by people with long-term conditions to help adjustment and coping. Cartoons can help provide clarity and understanding and could address concerns related to health literacy. Using cartoons to engage and motivate people is a consideration untapped by conventional theories with the potential to improve information to support self-management
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