705 research outputs found

    Local Volume Effects in the Generalized Pseudopotential Theory

    Get PDF
    The generalized pseudopotential theory (GPT) is a powerful method for deriving real-space transferable interatomic potentials. Using a coarse-grained electronic structure, one can explicitly calculate the pair ion-ion and multi-ion interactions in simple and transition metals. Whilst successful in determining bulk properties, in central force metals the GPT fails to describe crystal defects for which there is a significant local volume change. A previous paper [PhysRevLett.66.3036 (1991)] found that by allowing the GPT total energy to depend upon some spatially-averaged local electron density, the energetics of vacancies and surfaces could be calculated within experimental ranges. In this paper, we develop the formalism further by explicitly calculating the forces and stress tensor associated with this total energy. We call this scheme the adaptive GPT (aGPT) and it is capable of both molecular dynamics and molecular statics. We apply the aGPT to vacancy formation and divacancy binding in hcp Mg and also calculate the local electron density corrections to the bulk elastic constants and phonon dispersion for which there is refinement over the baseline GPT treatment.Comment: 11 pages, 6 figure

    Boundary regularity of conformally compact Einstein metrics

    Full text link
    We show that C^2 conformally compact Riemannian Einstein metrics have conformal compactifications that are smooth up to the boundary in dimension 3 and all even dimensions, and polyhomogeneous in odd dimensions greater than 3.Comment: Latex2e, 25 pages. This is the final version accepted for publication in the Journal of Differential Geometr

    The rotary converter

    Get PDF
    Citation: Skinner, John T. and Axtell, Clinton Jesse. The rotary converter. Senior thesis, Kansas State Agricultural College, 1904.Morse Department of Special CollectionsIntroduction: The rotary converter as a practical element in the transmission of power is a machine of comparatively recent date. Among the first practical converters noted was one exhibited at the Frankfort Exposition of 1891. This machine was of the flat ring, Schuckert make, fitted with four collecting rings outside of the bearing at the commutator end. This machine was operated successfully in its manifold and diverse functions. The rapid growth of the converter and its extension into a large field of usefulness has taken place during the past eight years. A brief comparison of its growth will be mentioned later in this discussion

    The Development of Intervention E-Learning Materials and Implementation Techniques For Cyber-Security Behaviour Change

    Get PDF
    Many organisations show compliance in running security awareness programmes, but this does not necessarily mean end users will change their behavior. This highlights one of the main challenges in cyber security. Providing awareness in a tool is a useful first step but it doesn’t necessarily lead to changing behaviour [3]. In contrast, completing compliance or achieving competence can actually lead people to being more averse to change than before or even partaking in risky behaviour. This paper describes the collaboration between a specialist computer business (LiMETOOLS) and psychology academics to draw on psychology theory (e.g. Social Cognitive Theory, [4]) and pedagogy (e.g. self-directed learning) to create innovative techniques using interactive learning tools resulting in behaviour change. The aim of this article is to show how we have moved beyond developing materials that change awareness, to those that effectively change digital behaviour. We examine methodologies that can be integrated within online learning tools to embed text, video clips, gamification, and quizzes to encourage measurable cyber security behaviour change. A challenge within behaviour change is the maintenance of these behaviours and we are exploring the potential impact of using ‘drip-feed learning’ in the form of a short video magazine with embedded quizzes and ‘nudges’ of behaviour changes that have previously learnt, delivered over a long period of time in very short stimulus packages

    Broadening Responsibilities: Consideration Of The Potential To Broaden The Role Of Uniformed Fire Service Employees

    Get PDF
    What is this report about? This report, commissioned by the National Joint Council for Local Authority Fire and Rescue Services (NJC), aims to identify what impact, if any, firefighters can have on the delivery of emergency medical response and wider community health interventions in the UK. What are the overall conclusions? Appropriately trained and equipped firefighters co-responding1 to targeted, specific time critical medical events, such as cardiac arrest, can improve patient survival rates. The data also indicate that there is support from fire service staff – and a potential need from members of the public, particularly the elderly, isolated or vulnerable – to expand ‘wider work’. This includes winter warmth assessments, Safe and Well checks, community defibrillator training and client referrals when staff believe someone may have dementia, are vulnerable or even, for example, have substance dependencies such as an alcohol addiction. However, there is currently insufficient data to estimate the net benefit of this work

    Defining Digital Addiction: Key Features from the Literature

    Get PDF
    Within recent years there has been increasing societal concern around the compulsive and excessive use of digital and Internet-enabled devices, such as the use of social media or online video gaming, and associated psychological and physical harms. However, problematic use or addictive behaviours are not yet included as diagnosable mental health issues in any major diagnostic system in Western countries and the conceptualisations of the phenomena are still inconsistent. To address this issue, the present study reviewed the current conceptualisations of digital addiction used within the research literature and identified common features of the definition of digital addiction. Definitions of the phenomenon were extracted from 47 studies, and they were analysed using a content analysis approach. The initial process assessed definitions for features of digital addiction within Internet, gaming and smartphone addiction. Two higher-order themes were identified, which focused on the harm caused by the phenomenon and on the user’s behaviours associated with the phenomenon. It was also found that key constructs are not specific to the usage domain, i.e. whether it is related to gaming, Internet or smartphone use. Several core features were found across different conceptualisations of digital addiction within the literature; however, it was also noted that some features are subjective and inconsistently applied. If a decision is to be reached on whether the phenomenon is a mental health disorder, then clearer definitions must be created

    Think twice before starting a new trial; what is the impact of recommendations to stop doing new trials?

    Full text link
    ObjectivesIn evidence-based medicine, we base our conclusions on the effectiveness of interventions on the results of high-quality meta-analysis. If a new randomized controlled trial (RCT) is unlikely to change the pooled effect estimate, conducting the new trial is a waste of resources. We evaluated whether recommendations not to conduct further RCTs reduced the number of trials registered for two scenarios.MethodsAnalysis of registered trials on the World Health Organisation (WHO) International Clinical Trials Registry Platform (ICTRP). We regarded trial protocols relevant if they evaluated the effectiveness of (1) exercise for chronic low back pain (LBP) and (2) cognitive behavioural therapy (CBT) for chronic pain. We calculated absolute and relative numbers and change of registered trials in a pre-set time window before and after publication of the recommendations, both published in 2012.ResultsWe found 1,574 trials registered in the WHO trial registry for exercise in LBP (459 before 2012; 1,115 after) and 5,037 trials on chronic pain (1,564 before 2012; 3,473 after). Before 2012, 13 trials on exercise for LBP (out of 459) fit the selection criteria, compared to 42 trials (out of 1,115) after, which represents a relative increase of 33%. Twelve trials (out of 1,564) regarding CBT for chronic pain, fit the selection criteria before 2012 and 18 trials (out of 3,473) after, representing a relative decrease of 32%. We found that visibility, media exposure and strength of the recommendation were related to a decrease in registered trials.ConclusionsRecommendations not to conduct further RCTs might reduce the number of trials registered if these recommendations are strongly worded and combined with social media attention

    Room temperature exsolution of CdS nanodots on A-site deficient cotton-ball like titanate perovskite nanoparticles for H2 production under visible light

    Get PDF
    Funding: The authors thank EPSRC for funding for a Critical Mass Project EP/R023522/1 and electron microscopy facilities EP/R023751/1 and EP/L017008/1.Exsolution of nanoparticles followed by chemical treatment (“chemistry at a point”) is a very exciting approach to the smart design of functional materials such as visible light active photocatalysts. Unfortunately, the usually utilized thermal reduction approach is not feasible for low melting point metals and compounds such as Cd and CdO. Here a hydrothermal approach to prepare exsolved CdS nanodots on cotton ball-like perovskite supports is described. The titanate-based photocatalyst is synthesized using a hydrothermal process followed by room-temperature sulfidation. The hydrothermal route directs A-site doping of Cd2+ via hydroxyl group incorporation in the titanate lattice. Formation of CdS via exsolution provides a high H2 production mass activity of 3050 ”mol g−1 h−1 under visible light with only 5 mol.% Cd doping of the titanate. Moreover, the strong CdS-support interaction offers good cycling stability under UV–vis and visible light irradiation. This is the first report describing the exsolution of CdS nanodots at room temperature and shows its advantages for photocatalytic activity.Publisher PDFPeer reviewe
    • 

    corecore