12 research outputs found

    A transient isotopic study for investigating important design parameters of NiCo/Ce0.75Zr0.25O2-δ catalyst for the dry reforming of methane

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    The effects of metal loading and particle size of NiCo alloy deposited on Ce0.75Zr0.25O2-δ carrier on the carbon reaction paths of dry reforming of methane at 750 °C with respect to the observed long-term activity profiles was elucidated. Small NiCo nanoparticles (7.8 nm) showed progressive deactivation as opposed to the larger ones (43 nm) which exhibited self-regeneration. Towards this goal, appropriate transient kinetic isotopic experiments (use of 18O2 and 13CO2) and other catalyst characterization studies (transient isothermal reduction, XPS, HAADF-STEM-EDX) were conducted. This work paves the way for the design of highly active and coke-resistant reducible metal oxides-supported NiCo

    The healthcare system and provision of oral healthcare in European Union member states. Part 4: Greece

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    This paper presents a description of the healthcare system and how oral healthcare is organised and provided in Greece, a country in a deep economic and social crisis. The national health system is underfunded, with severe gaps in staffing levels and the country has a large private healthcare sector. Oral healthcare has been largely provided in the private sector. Most people are struggling to survive and have no money to spend on general and oral healthcare. Unemployment is rising and access to healthcare services is more difficult than ever. Additionally, there has been an overproduction of dentists and no development of team dentistry. This has led to under or unemployment of dentists in Greece and their migration to other European Union member states, such as the United Kingdom, where over 600 Greek dentists are currently working. © 2015 British Dental Association

    FLeet: Online Federated Learning via Staleness Awareness and Performance Prediction

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    International audienceFederated Learning (FL) is very appealing for its privacy benefits: essentially, a global model is trained with updates computed on mobile devices while keeping the data of users local. Standard FL infrastructures are however designed to have no energy or performance impact on mobile devices, and are therefore not suitable for applications that require frequent (online) model updates, such as news recommenders. This paper presents FLeet, the first Online FL system, acting as a middleware between the Android OS and the machine learning application. FLeet combines the privacy of Standard FL with the precision of online learning thanks to two core components: (i) I-Prof, a new lightweight profiler that predicts and controls the impact of learning tasks on mobile devices, and (ii) AdaSGD, a new adaptive learning algorithm that is resilient to delayed updates. Our extensive evaluation shows that Online FL, as implemented by FLeet, can deliver a 2.3× quality boost compared to Standard FL, while only consuming 0.036% of the battery per day. I-Prof can accurately control the impact of learning tasks by improving the prediction accuracy up to 3.6× (computation time) and up to 19× (energy). AdaSGD outperforms alternative FL approaches by 18.4% in terms of convergence speed on heterogeneous data
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