78 research outputs found

    Eco-innovazione dei processi produttivi: analisi e azioni di intervento per l'efficentamento energetico

    Get PDF
    La crisi congiunturale ha notevolmente appesantito la situazione del Settore della Pesca già strutturalmente difficile. Nel “Rapporto Annuale sulla Pesca e sull’Acquacoltura in Sicilia”, redatto dall’Osservatorio della Pesca, si afferma che “in un contesto prospettico così difficile la quantità di energia specifica, ossia energia consumata per kg di prodotto (kWh/kg di prodotto), necessaria a fornire il prodotto ittico sul mercato deve diventare un indicatore guida per le politiche di ammodernamento ed innovazione. Pertanto è necessaria un’opportuna conoscenza di tutti i consumi energetici necessari per la produzione che, grazie all’utilizzo di pochi e significativi indicatori (quali l’energia per unità di prodotto, la quantità d’acqua per unità di prodotto e le emissioni ed i rilasci inquinanti per unità di prodotto), consenta di descrivere dinamicamente lo stato e la tendenza della filiera ittica”. In tale quadro, è evidente che il fattore energetico rappresenta una componente che ha una rilevante incidenza sulla competitività della Filiera e che, spesso, i vari anelli produttivi “pagano” costi di gestione elevati a causa dell’inefficienza energetica. In un contesto di consumatori sempre più attenti al rispetto ambientale e alla sostenibilità dei prodotti, l’impatto che i sistemi produttivi non efficienti hanno sull’ambiente ha un ritorno negativo anche rispetto all’immagine complessiva della Filiera e dei prodotti: in tal senso, la mancanza di sistemi di gestione ambientale efficaci ed adeguati può risultare, nel lungo periodo, un elemento di penalizzazione sui mercati. Nel progetto “Centro di certificazione e prova del Distretto”, Piani di sviluppo di filiera, linea di intervento: 5.1.1.1 – piano integrato dei servizi comuni, l’attività svolta da questo laboratorio, ECO-INNOVAZIONE DEI PROCESSI PRODUTTIVI, ha lo scopo di calcolare i consumi energetici delle aziende del distretto, prese in esame come campione di studio, e studiare le possibili azioni per ottimizzare, mitigare i consumi e/o l’impatto ambientale come minore emissione di CO2 in atmosfera. Tali attività consentiranno al Distretto, alle sue aziende e tutte le altre aziende del settore di poter conoscere l'energia consumata e quella potenzialmente risparmiata dalle eventuali azioni di efficientamento che saranno proposte da questo gruppo di lavoro

    Design and optimization of Metallic Foam Shell protective device against flying ballast impact damage in railway axles

    Get PDF
    Abstract Ballast impacts can initiate surface defects that cause abrupt failure of the axle and derailment of the railway vehicle. According to the Federal Railroad Administration the axle and bearing failure costs around 89 million dollars and causes 46 derailments in the US per year (2005–2010). In this study, the authors have suggested a novel protective mechanism (Metallic Foam Shell – MFS) by using a lightweight sandwich panel. At the first step, a preliminary study is conducted, followed up by the numerical simulations to determine the applicable materials. At the next step, experimental tests were performed to assess the efficiency of the suggested device against flying ballast impacts. An extended non-destructive (NDT) evaluation has been performed in order to find the most suitable technique for damage detection of the proposed device when on-service. The studied cases were GFRP and Aluminium sandwich panels, having an aluminium foam core with different densities and thicknesses. The results showed that the MFS can absorb up to 90% of the initial impact energy and significantly decrease the chance of rebounding impact to the other components. Moreover, the results were also analysed in order to propose the most reliable NDT method for this specific application

    Design of an Innovative Hybrid Sandwich Protective Device for Offshore Structures

    Get PDF
    Lightweight foam sandwich structures have excellent energy absorption capacity, combined with good mechanical properties and low density. The main goal of this study is to test the application of an innovative hybrid sandwich protective device in an offshore wind turbine (OWT). The results are useful for offshore structure applications. Different lightweight materials (aluminum foam, agglomerated cork, and polyurethane foam) were investigated using experimental tests and numerical simulations. Closed-cell aluminum foam showed the best performance in terms of the energy absorption capacity during an impact. As such, a Metallic Foam Shell (MFS) device was proposed for the fender of offshore wind turbines. A finite element model of a ship-OWT collision scenario was developed to analyze the response of a fender with the MFS device under repeated impacts. The proposed MFS fender can be used efficiently in a wide temperature range, allowing it to be used in harsh climatic conditions

    Impact of sleep disorders on behavioral issues in preschoolers with autism spectrum disorder

    Get PDF
    BackgroundSleep disorders are one of the most common problems in children with Autism Spectrum Disorder (ASD). However, they often tend to be underdiagnosed and incorrectly treated in clinical practice. This study aims to identify sleep disorders in preschool children with ASD and to explore their relationship with the core symptoms of autism, the child's developmental and cognitive level as well as the psychiatric comorbidities. MethodsWe recruited 163 preschool children with a diagnosis of ASD. The Children's Sleep Habits Questionnaire (CSHQ) assessed sleep conditions. Multiple standardized tests were used to evaluate intellectual abilities, the presence of repetitive behaviors (through the Repetitive Behavior Scale-Revised), as well as the emotional-behavioral problems and the psychiatric comorbidities (through the Child Behavior Checklist -CBCL 1(1/2)-5). ResultsThe results showed that poor disorders had consistently higher scores in all areas assessed by the CSHQ and on the CBCL across all domains. The correlational analysis showed that severe sleep disorders were associated with higher scores in internalizing, externalizing, and total problems at the CBCL syndromic scales, and in all DSM-oriented CBCL subscales. Moreover, we found that the association between sleep disorders and restricted and repetitive behaviors (RRBs) is explained by the anxiety-related symptoms. ConclusionBased on these findings, the study recommends that screening for sleep problems followed by early intervention should constitute a routine part of clinical practice for children with ASD

    Event reconstruction for KM3NeT/ORCA using convolutional neural networks

    Get PDF
    The KM3NeT research infrastructure is currently under construction at two locations in the Mediterranean Sea. The KM3NeT/ORCA water-Cherenkov neutrino detector off the French coast will instrument several megatons of seawater with photosensors. Its main objective is the determination of the neutrino mass ordering. This work aims at demonstrating the general applicability of deep convolutional neural networks to neutrino telescopes, using simulated datasets for the KM3NeT/ORCA detector as an example. To this end, the networks are employed to achieve reconstruction and classification tasks that constitute an alternative to the analysis pipeline presented for KM3NeT/ORCA in the KM3NeT Letter of Intent. They are used to infer event reconstruction estimates for the energy, the direction, and the interaction point of incident neutrinos. The spatial distribution of Cherenkov light generated by charged particles induced in neutrino interactions is classified as shower- or track-like, and the main background processes associated with the detection of atmospheric neutrinos are recognized. Performance comparisons to machine-learning classification and maximum-likelihood reconstruction algorithms previously developed for KM3NeT/ORCA are provided. It is shown that this application of deep convolutional neural networks to simulated datasets for a large-volume neutrino telescope yields competitive reconstruction results and performance improvements with respect to classical approaches

    Event reconstruction for KM3NeT/ORCA using convolutional neural networks

    Get PDF
    The KM3NeT research infrastructure is currently under construction at two locations in the Mediterranean Sea. The KM3NeT/ORCA water-Cherenkov neutrino de tector off the French coast will instrument several megatons of seawater with photosensors. Its main objective is the determination of the neutrino mass ordering. This work aims at demonstrating the general applicability of deep convolutional neural networks to neutrino telescopes, using simulated datasets for the KM3NeT/ORCA detector as an example. To this end, the networks are employed to achieve reconstruction and classification tasks that constitute an alternative to the analysis pipeline presented for KM3NeT/ORCA in the KM3NeT Letter of Intent. They are used to infer event reconstruction estimates for the energy, the direction, and the interaction point of incident neutrinos. The spatial distribution of Cherenkov light generated by charged particles induced in neutrino interactions is classified as shower-or track-like, and the main background processes associated with the detection of atmospheric neutrinos are recognized. Performance comparisons to machine-learning classification and maximum-likelihood reconstruction algorithms previously developed for KM3NeT/ORCA are provided. It is shown that this application of deep convolutional neural networks to simulated datasets for a large-volume neutrino telescope yields competitive reconstruction results and performance improvements with respect to classical approaches

    Nondestructive Evaluation of Aluminium Foam Panels Subjected to Impact Loading

    Get PDF
    Aluminium foam sandwich structures have excellent energy absorption capacity, combined with good mechanical properties and low density. Some of the authors of this paper proposed an innovative Metallic Foam Shell protective device against flying ballast impact damage in railway axles. A closed-cell aluminium foam was chosen for the Metallic Foam Shell device. The main goal of this study was the experimental investigation of the impact responses of aluminium foam panels. Low velocity impact tests were carried out at different energies on different types of aluminium foam panels in order to investigate the effects of some parameters, such as core thickness, skin material and layer. Tests were conducted at repeated impacts on aluminium foam panels without and with skins made of aluminium and glass fibre-reinforced polymer. The experimental results were compared and the impacted panels were investigated by means of the nondestructive techniques ultrasonic phased array and digital radiography

    A-Posteriori Versus A-Priori Access Strategies in Slotted All-Optical WDM Rings

    No full text
    The paper presents the concept of "a posteriori" access strategy, as opposed to the previously studied concept of "a priori" strategy, to provide a fair and ecient access technique in slotted wavelength division multiplexing (WDM) rings under a large variety of trac patterns. Using a posteriori strategies, the source node selects the packet for transmission based on the state of the WDM channels in the arriving slot, thus adapting the access decision to the instantaneous trac in the various channels. The packet selection process of a posteriori strategies, when contrasted with a priori strategies, yields fair and ecient utilization of the ring bandwidth without requiring the equalization of the ring latency, nor imposing restrictions on the trac patterns allowed in the system. Since the same features cannot be provided by a priori access strategies, a posteriori strategies oers a more versatile access control that justies the higher implementation complexity due to the multi-channel se..
    • …
    corecore