320 research outputs found

    Synchro-push: A new production control paradigm

    Get PDF
    The paper aims at proposing a new production control paradigm, the Synchro-push, that offers a step forward with respect to the traditional push and pull production paradigms as for plant re-configurability power and quick reaction to demand changes: in fact, theoretically, it offers the advantages of the two traditional approaches without suffering their drawbacks. This could be of advantage for any manufacturing company and especially for SMEs (Small-Medium Enterprises), acting as a support against worldwide competition. The paper presents a brief history of the evolution of the push and pull approaches, the comparison between them and among the different alternatives that have been proposed in literature for their implementation. It presents the new approach, its theory and the subsequent industrial implications. The new approach is now made possible by the development of innovative smart technologies that allow the close-to-real-time decision making in scheduling and a higher level of modularity in the plant

    Quantum Crystallography in the Last Decade: Developments and Outlooks

    Get PDF
    In this review article, we report on the recent progresses in the field of quantum crystallography that has witnessed a massive increase of production coupled with a broadening of the scope in the last decade. It is shown that the early thoughts about extracting quantum mechanical information from crystallographic experiments are becoming reality, although a century after prediction. While in the past the focus was mainly on electron density and related quantities, the attention is now shifting toward determination of wavefunction from experiments, which enables an exhaustive determination of the quantum mechanical functions and properties of a system. Nonetheless, methods based on electron density modelling have evolved and are nowadays able to reconstruct tiny polarizations of core electrons, coupling charge and spin models, or determining the quantum behaviour at extreme conditions. Far from being routine, these experimental and computational results should be regarded with special attention by scientists for the wealth of information on a system that they actually contain

    Electron transfer and CO addition to polynitrido cobalt carbonyl clusters: Parallel pathways for conversion of the [Co10N2(CO)(19)](4-) anion to the novel [Co11N2(CO)(21)](3-) anion

    Get PDF
    The redox aptitude of the dinitrido anion [Co10N2(CO)19]4- has been tested from both chemical and electrochemical points of view, together with its reactivity toward CO that induces disproportionation. In any case, through a remarkable overlapping of intermediate steps, the new anion [Co11N2(CO)21]3- (4) is eventually obtained. A detailed study of the pathways to 4 allowed the identification of three labile intermediates by their characteristic IR spectra as well as their electrochemical and paramagnetic properties. The unprecedented structure of trianion 4 has been studied in details in two different crystalline salts

    Maintenance plan adaptation based on health ratings of servitised machines through a fleet-wide machine clustering method

    Get PDF
    The increased requests for value-added services to integrate product performance push manufacturing companies to extend their service offerings to meet customers’ needs. In this context, maintenance planning can leverage new possibilities offered by digital technologies for data analytics services. The present research then proposes an approach for maintenance plan adaptation based on a data-driven method applied over a fleet of machines installed in different production sites. The method relies on collaborative prognostics to develop a clustering of machines’ behaviour aimed at providing the health ratings of the machines and the subsequent maintenance plan adaptation due to the deviation from the expected behaviour. The method is adopted from the perspective of an Original Equipment Manufacturer, as part of a transformation path towards an advanced provision of digitalization for maintenance service offerings. The method is validated in the context of two lines at selected customer’s premises. This demonstrates the viability and effectiveness of adapting the maintenance plans thanks to the data analytics in light of the current behaviour of the machines within the lines

    Kinetic energy of solid neon by Monte Carlo with improved Trotter- and finite-size extrapolation

    Full text link
    The kinetic energy of solid neon is calculated by a path-integral Monte Carlo approach with a refined Trotter- and finite-size extrapolation. These accurate data present significant quantum effects up to temperature T=20 K. They confirm previous simulations and are consistent with recent experiments.Comment: Text and figures revised for minor corrections (4 pages, 3 figures included by psfig

    Geometric dynamical observables in rare gas crystals

    Full text link
    We present a detailed description of how a differential geometric approach to Hamiltonian dynamics can be used for determining the existence of a crossover between different dynamical regimes in a realistic system, a model of a rare gas solid. Such a geometric approach allows to locate the energy threshold between weakly and strongly chaotic regimes, and to estimate the largest Lyapunov exponent. We show how standard mehods of classical statistical mechanics, i.e. Monte Carlo simulations, can be used for our computational purposes. Finally we consider a Lennard Jones crystal modeling solid Xenon. The value of the energy threshold turns out to be in excellent agreement with the numerical estimate based on the crossover between slow and fast relaxation to equilibrium obtained in a previous work by molecular dynamics simulations.Comment: RevTeX, 19 pages, 6 PostScript figures, submitted to Phys. Rev.

    HuD is a neural translation enhancer acting on mTORC1-responsive genes and counteracted by the Y3 small non-coding RNA

    Get PDF
    The RNA-binding protein HuD promotes neurogenesis and favors recovery from peripheral axon injury. HuD interacts with many mRNAs, altering both stability and translation efficiency. We generated a nucleotide resolution map of the HuD RNA interactome in motor neuron-like cells, identifying HuD target sites in 1,304 mRNAs, almost exclusively in the 3' UTR. HuD binds many mRNAs encoding mTORC1-responsive ribosomal proteins and translation factors. Altered HuD expression correlates with the translation efficiency of these mRNAs and overall protein synthesis, in a mTORC1-independent fashion. The predominant HuD target is the abundant, small non-coding RNA Y3, amounting to 70% of the HuD interaction signal. Y3 functions as a molecular sponge for HuD, dynamically limiting its recruitment to polysomes and its activity as a translation and neuron differentiation enhancer. These findings uncover an alternative route to the mTORC1 pathway for translational control in motor neurons that is tunable by a small non-coding RNA

    An ontological modelling of multi-attribute criticality analysis to guide Prognostics and Health Management program development

    Get PDF
    Digital technologies are becoming more pervasive and industrial companies are exploiting them to enhance the potentialities related to Prognostics and Health Management (PHM). Indeed, PHM allows to evaluate the health state of the physical assets as well as to predict their future behaviour. To be effective in developing PHM programs, the most critical assets should be identified so to direct modelling efforts. Several techniques could be adopted to evaluate asset criticality; in industrial practice, criticality analysis is amongst the most utilised. Despite the advancement of artificial intelligence for data analysis and predictions, the criticality analysis, which is built upon both quantitative and qualitative data, has not been improved accordingly. It is the goal of this work to propose an ontological formalisation of a multi-attribute criticality analysis in order to i) fix the semantics behind the terms involved in the analysis, ii) standardize and uniform the way criticality analysis is performed, and iii) take advantage of the reasoning capabilities to automatically evaluate asset criticality and associate a suitable maintenance strategy. The developed ontology, called MOCA, is tested in a food company featuring a global footprint. The application shows that MOCA can accomplish the prefixed goals; specifically, high priority assets towards which direct PHM programs are identified. In the long run, ontologies could serve as a unique knowledge base that integrate multiple data and information across facilities in a consistent way. As such, they will enable advanced analytics to take place, allowing to move towards cognitive Cyber Physical Systems that enhance business performance for companies spread worldwide

    Preliminary investigation of the state of the art on digital servitization for Industrial Asset lifecycle Management

    Get PDF
    This paper aims to investigate how digital servitization can act as a game changer of Industrial Asset lifecycle Management in manufacturing. Building on a literature review, two main research streams are identified when talking about digital servitization for asset management. A part of the analyzed papers reports the Product-Service Systems as the solutions developed by Original Equipment Manufacturers for managing users' industrial assets; this primarily focuses on the required change of the value proposition in the offerings due to business models. These papers address a few asset-related processes like the real-time status/process monitoring, or the prognosis and diagnosis of failures. A higher collection of the identified papers addresses the opportunities brought by digitalization to the users of the assets for developing digital services; this involves more actors, and leverages both data-sharing and collaboration. A good portion of this research stream considers the digital capabilities from advanced platforms enabled by infrastructures as Cyber-Physical Systems and Digital Twin models for developing smart services solutions. The digital platforms, open and interoperable, appear to be a promising means where to start from in order to develop the collaborative approaches required by Industrial Asset lifecycle Management; correspondingly, a wider set of asset-related processes can be supported
    corecore