8,931 research outputs found

    Medical Device Software: From Requirements to Certification

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    The role of software in healthcare is getting more and more pervasive. Nevertheless, manufacturers sometimes forget that these software are medical devices and must be certified according to the EU Medical Device Regulation 2017/745. In this work we propose a pipeline for developing a Medical Device Software (MDS) compliant with the regulations and certifiable. The pipeline includes the phase of requirements elicitation, risk assessment and analysis of effectiveness as key elements. The preparation of the technical file should be carried out in parallel with the MDS development. In the overall, it can be stated that the certification process starts with the conceptualization of the MDS and proceeds all along its design and implementation

    The advantages of fly ash use in concrete structures

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    In this paper the use of fly ash for particular High Strength Concrete (HSC) realizations is investigated. The use of fly ash as a partial replacement of Portland cement in HSC seems a valid solution in particular for a sustainable construction design, considering the interesting HSC performances (in terms of strength and durability) and the economic aspects (in terms of waste material's reuse from industrial process). Fly ashes have been employed in the past especially for underground structures. Nowadays, their use is under evaluation also for elevation structures. In this paper, the most important technical regulations about the use of fly ash for the concrete mix design are discussed. The increase of the mechanical resistance, the better protection against chemical agents attacks and freezing - thawing cycles using fly ashes are also show. Moreover, in comparison to the fresh concrete, the benefits related to the minor water/cement (w/c) ratio are presented, in the same workability conditions. Additional considerations are carried out about the hydration process: the mixture produces less heat for the lowering of the C3A and C3S percentages using fly ash. Finally, a greater concrete impermeability obtained using fly ash, due to the presence of a lower hydrolysis content, which leads to an increment of the cement paste porosity, has been evidenced. All of mentioned benefits shows the fly ash use in the High Strength Concrete (HSC) is a valid solution against many problems interested negatively the concrete mix - design and the mix - production

    The use of fly ash in high strength concrete mix design

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    In this paper the use of fly ash for particular High Strength Concrete (HSC) realizations is investigated. The use of fly ash as a partial replacement of Portland cement in HSC seems a valid solution in particular for a sustainable construction design, considering the interesting HSC performances and the economic aspects. Obviously the advantages demonstrated for the underground constructions can be also evaluated for the structures in elevation. In this paper the most important technical regulations about the use of fly ash for the concrete mix design are discussed and it’s shown the increase of the mechanical resistance and the better protection against the chemical agents attacks and against the freezing and thawing cycles using fly ash. Moreover, in comparison to the fresh concrete, it’s presented the benefits related to the minor ratio water/cement (defined by w/c) in the same conditions of workability. Additional considerations are carried out about the hydration process: the mixture produces less heat for the lowering of the C3A and C3S percentages using fly ash. Finally, a greater concrete impermeability obtained using fly ash, due to the presence of a lower hydrolysis content, which leads to an increment of the cement paste porosity, has been evidence

    Diffusive spreading and mixing of fluid monolayers

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    The use of ultra-thin, i.e., monolayer films plays an important role for the emerging field of nano-fluidics. Since the dynamics of such films is governed by the interplay between substrate-fluid and fluid-fluid interactions, the transport of matter in nanoscale devices may be eventually efficiently controlled by substrate engineering. For such films, the dynamics is expected to be captured by two-dimensional lattice-gas models with interacting particles. Using a lattice gas model and the non-linear diffusion equation derived from the microscopic dynamics in the continuum limit, we study two problems of relevance in the context of nano-fluidics. The first one is the case in which along the spreading direction of a monolayer a mesoscopic-sized obstacle is present, with a particular focus on the relaxation of the fluid density profile upon encountering and passing the obstacle. The second one is the mixing of two monolayers of different particle species which spread side by side following the merger of two chemical lanes, here defined as domains of high affinity for fluid adsorption surrounded by domains of low affinity for fluid adsorption.Comment: 12 pages, 3 figure

    Finiteness of topological entropy for locally compact abelian groups

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    We study the locally compact abelian groups in the class E_infty, that is, having only continuous endomorphisms of finite topological entropy, and in its subclass E_0, that is, having all continuous endomorphisms with vanishing topological entropy. We discuss the reduction of the problem to the case of periodic locally compact abelian groups, and then to locally compact abelian p-groups. We show that locally compact abelian p-groups of finite rank belong to E_infty, and that those of them that belong to E_0 are precisely the ones with discrete maximal divisible subgroup. Furthermore, the topological entropy of endomorphisms of locally compact abelian p-groups of finite rank coincides with the logarithm of their scale. The backbone of the paper is the Addition Theorem for continuous endomorphisms of locally compact abelian groups. Various versions of the Addition Theorem are established in the paper and used in the proofs of the main results, but its validity in the general case remains an open problem

    Quantum fluctuations in thin superconducting wires of finite length

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    In one dimensional wires, fluctuations destroy superconducting long-range order and stiffness at finite temperatures; in an infinite wire, quasi-long range order and stiffness survive at zero temperature if the wire's dimensionless admittance μ\mu is large, μ>2\mu > 2. We analyze the disappearance of this superconductor-insulator quantum phase transition in a finite wire and its resurrection due to the wire's coupling to its environment characterized through the dimensionless conductance KK. Integrating over phase slips, we determine the flow of couplings and establish the μ\mu--KK phase diagram.Comment: 4 pages, 2 figure

    SiPM and front-end electronics development for Cherenkov light detection

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    The Italian Institute of Nuclear Physics (INFN) is involved in the development of a demonstrator for a SiPM-based camera for the Cherenkov Telescope Array (CTA) experiment, with a pixel size of 6×\times6 mm2^2. The camera houses about two thousands electronics channels and is both light and compact. In this framework, a R&D program for the development of SiPMs suitable for Cherenkov light detection (so called NUV SiPMs) is ongoing. Different photosensors have been produced at Fondazione Bruno Kessler (FBK), with different micro-cell dimensions and fill factors, in different geometrical arrangements. At the same time, INFN is developing front-end electronics based on the waveform sampling technique optimized for the new NUV SiPM. Measurements on 1×\times1 mm2^2, 3×\times3 mm2^2, and 6×\times6 mm2^2 NUV SiPMs coupled to the front-end electronics are presentedComment: In Proceedings of the 34th International Cosmic Ray Conference (ICRC2015), The Hague, The Netherlands. All CTA contributions at arXiv:1508.0589

    Simulation of the Impact on the Workload of the Enlargement of the Clinical Staff of a Specialistic Reference Center

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    Quality of care and patient satisfaction are important aspects of high standard care. If clinical staff is subject to an elevated workload there is a possible decrease of both. This justifies the development of tools to quantify the workload and to find organizational changes that will normalize it. We have previously developed a simulation system to quantify the workload of the staff working in a regional reference center for the treatment of bleeding and hemorrhagic disorders. The goal of this new work is to simulate, through an agent-based model, the impact of adding a physician to the staff. Ten sets of initial parameters were defined to simulate ten typical weeks. Results show that the introduction of the new physician together with a second ambulatory room can reduce the workload of all the staff to the expected 8-hour. In this situation, in which the staff workload does not exceed the daily capacity, we may suppose that an increase in the quality of care and patient satisfaction will be possible
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