1,022 research outputs found

    reuse of tires textile fibers in plastic compounds is this scenario environmentally sustainable

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    Abstract Even if specific directives have been issued to regulate the management of End of Life Tires (ELT), several materials are still not properly recovered. This is the case of textile fibers obtained from the treatment of ELTs. This study aims to investigate and quantify the environmental impacts related to the reuse of tires textile fibers as second-life material for the preparation of plastic compounds. The Life Cycle Assessment methodology has been used to compare the baseline scenarios (landfilling and incineration) with the reuse scenarios. Results obtained confirms that reuse scenarios are generally more environmental sustainable than the currently implemented strategies

    Reuse scenarios of tires textile fibers: an environmental evaluation

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    Abstract End of Life Tires (ELT) constitute a major portion of End of life Vehicles (ELV). The treatment process of ELTs is primarily aimed at recovering steel and rubber, which jointly represent the main portion of the ELT material and are currently applied in different sectors. During the treatment of ELTs, other sub-products are generated in significant quantities (about 10-15% in weight), as textile fibers that currently are landfilled or used for energy recovery. The aim of this study is a comparative evaluation of the environmental impacts related to three different end of life scenarios for the textile fibers. In addition to landfilling and incineration, this study considers the possibility to reuse textile fibers as reinforcement in bituminous conglomerates. Results obtained through the Life Cycle Assessment study confirms that the reuse scenario leads to a relevant reduction of impacts in terms of Global Warming Potential. However, by considering other environmental metrics the reuse scenario is not always the less impactful one

    optimization of energy efficiency of a production site a method to support data acquisition for effective action plans

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    Abstract Nowadays the efficient use of energy has acquired a significant importance in the industrial sector. Moreover, stringent regulations on environmental impact lead companies to tread a path towards energy efficiency in short terms to avoid penalties. The goal of this work is to propose a structured method to perform fast and simplified energy assessments. The latter starts from a proper classification of process data, passing through an effective mapping in order to identify criticalities that have to be solved by innovative action plans. Method will be tested on a real case study

    Peridynamics for Predicting Pit-to-Crack Transition

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    Even though the failure mechanisms in aerospace structures are mainly governed by the incidence of fatigue loading, environmentally assisted fracture related pit-to-crack transition can still occur in many aluminum alloys, stainless steels and high strength low alloy steels. Despite of the relative rarity of this phenomenon, the consequent failures can be extremely destructive and lead to the loss of an aircraft. Prediction of damage evolution starting at corrosion pits acting as precursor to cracking has been hampered by a lack of insight into the process, as well as limitations in visualization and measurement techniques. In this regard, numerical modeling can be beneficial. The current study presents numerical predictions of pit evolution from a flat metal surface to realistic pit morphologies by using a new continuum mechanics formulation, peridynamics. Intergranular/transgranular pit-tocrack transition under different loading conditions and microstructural features are investigated without imposing any limiting assumption on the site of the crack initiation. Based on the numerical results, it can be concluded that microstructure has a significant effect for the prediction of pit-to-crack transition phenomenon

    Search for a light pseudoscalar Higgs boson in the boosted mu mu tau tau final state in proton-proton collisions at root s=13 TeV

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    A search for a light pseudoscalar Higgs boson (a) decaying from the 125 GeV (or a heavier) scalar Higgs boson (H) is performed using the 2016 LHC proton-proton collision data at root s = 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1), collected by the CMS experiment. The analysis considers gluon fusion and vector boson fusion production of the H, followed by the decay H -> aa -> mu mu tau tau, and considers pseudoscalar masses in the range 3.6 aa -> mu mu tau tau, down to 1.5 (2.0)x10(-4) for m(H) = 125 (300) GeV. Model-dependent limits on B(H -> aa) are set within the context of two Higgs doublets plus singlet models, with the most stringent results obtained for Type-III models. These results extend current LHC searches for heavier a bosons that decay to resolved lepton pairs and provide the first such bounds for an H boson with a mass above 125 GeV.Peer reviewe

    MUSiC : a model-unspecific search for new physics in proton-proton collisions at root s=13TeV

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    Results of the Model Unspecific Search in CMS (MUSiC), using proton-proton collision data recorded at the LHC at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb(-1), are presented. The MUSiC analysis searches for anomalies that could be signatures of physics beyond the standard model. The analysis is based on the comparison of observed data with the standard model prediction, as determined from simulation, in several hundred final states and multiple kinematic distributions. Events containing at least one electron or muon are classified based on their final state topology, and an automated search algorithm surveys the observed data for deviations from the prediction. The sensitivity of the search is validated using multiple methods. No significant deviations from the predictions have been observed. For a wide range of final state topologies, agreement is found between the data and the standard model simulation. This analysis complements dedicated search analyses by significantly expanding the range of final states covered using a model independent approach with the largest data set to date to probe phase space regions beyond the reach of previous general searches.Peer reviewe

    Measurement of prompt open-charm production cross sections in proton-proton collisions at root s=13 TeV

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    The production cross sections for prompt open-charm mesons in proton-proton collisions at a center-of-mass energy of 13TeV are reported. The measurement is performed using a data sample collected by the CMS experiment corresponding to an integrated luminosity of 29 nb(-1). The differential production cross sections of the D*(+/-), D-+/-, and D-0 ((D) over bar (0)) mesons are presented in ranges of transverse momentum and pseudorapidity 4 < p(T) < 100 GeV and vertical bar eta vertical bar < 2.1, respectively. The results are compared to several theoretical calculations and to previous measurements.Peer reviewe

    Search for dark photons in Higgs boson production via vector boson fusion in proton-proton collisions at √s = 13 TeV

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    A search is presented for a Higgs boson that is produced via vector boson fusion and that decays to an undetected particle and an isolated photon. The search is performed by the CMS collaboration at the LHC, using a data set corresponding to an integrated luminosity of 130 fb−1, recorded at a center-of-mass energy of 13 TeV in 2016–2018. No significant excess of events above the expectation from the standard model background is found. The results are interpreted in the context of a theoretical model in which the undetected particle is a massless dark photon. An upper limit is set on the product of the cross section for production via vector boson fusion and the branching fraction for such a Higgs boson decay, as a function of the Higgs boson mass. For a Higgs boson mass of 125 GeV, assuming the standard model production rates, the observed (expected) 95% confidence level upper limit on the branching fraction is 3.5 (2.8)%. This is the first search for such decays in the vector boson fusion channel. Combination with a previous search for Higgs bosons produced in association with a Z boson results in an observed (expected) upper limit on the branching fraction of 2.9 (2.1)% at 95% confidence level

    Reconstruction of signal amplitudes in the CMS electromagnetic calorimeter in the presence of overlapping proton-proton interactions

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    A template fitting technique for reconstructing the amplitude of signals produced by the lead tungstate crystals of the CMS electromagnetic calorimeter is described. This novel approach is designed to suppress the contribution to the signal of the increased number of out-of-time interactions per beam crossing following the reduction of the accelerator bunch spacing from 50 to 25 ns at the start of Run 2 of the LHC. Execution of the algorithm is sufficiently fast for it to be employed in the CMS high-level trigger. It is also used in the offline event reconstruction. Results obtained from simulations and from Run 2 collision data (2015-2018) demonstrate a substantial improvement in the energy resolution of the calorimeter over a range of energies extending from a few GeV to several tens of GeV.Peer reviewe
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