21 research outputs found

    Carbon-Fiber-Recycling Strategies: A Secondary Waste Stream Used for PA6,6 Thermoplastic Composite Applications

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    With a view to achieving sustainable development and a circular economy, this work focused on the possibility to valorize a secondary waste stream of recycled carbon fiber (rCF) to produce a 3D printing usable material with a PA6,6 polymer matrix. The reinforcing fibers implemented in the research are the result of a double-recovery action: starting with pyrolysis, long fibers are obtained, which are used to produce non-woven fabrics, and subsequently, fiber agglomerate wastes obtained from this last process are ground in a ball mill. The effect of different amounts of reinforcement at 5% and 10% by weight on the mechanical properties of 3D-printed thermoplastic composites was investigated. Although the recycled fraction was successfully integrated in the production of filaments for 3D printing and therefore in the production of specimens via the fused deposition modeling technique, the results showed that fibers did not improve the mechanical properties as expected, due to an unsuitable average size distribution and the presence of a predominant dusty fraction ascribed to the non-optimized ball milling process. PA6,6 + 10 wt.% rCF composites exhibited a tensile strength of 59.53 MPa and a tensile modulus of 2.24 GPa, which correspond to an improvement in mechanical behavior of 5% and 21% compared to the neat PA6,6 specimens, respectively. The printed composite specimens loaded with the lowest content of rCF provided the greatest improvement in strength (+9% over the neat sample). Next, a prediction of the "optimum" critical length of carbon fibers was proposed that could be used for future optimization of recycled fiber processing

    Domain Reduction Strategy for Stability Analysis of a NACA0012 airfoil

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    A new reduction domain strategy is applied in the framework of stability analysis for industrial applications. The aim of this work is to investigate if the geometrical approach proposed could be used as alternative or in combination with the numerical techniques that are currently employed for alleviating the prohibitive computational costs associated to the study of the stability of complex aerodynamic ows.Global linear stability analysis has been applied to a NACA0012 airfoil to study the transient bu�et phenomenon. The leading disturbance associated to bu�eting remains located in a inner región of the computational domain, making this problem a perfect test case for the domain reduction strategy presented here. The base ow has been obtained using DLR-TAU code on a �rst �ne mesh (100 chords) while di�erent, smaller meshes have been used to perform the stability analysis. The eigenvalue problem associated to stability has been solved using a Krylov-Schur projection method with direct LU preconditioning. Results show that the reduction in the computational domain is an useful technique to recover disturbances bounded in a particular region of the aforementioned domain

    Emergenza sismica nel centro Italia 2016-2017. Secondo rapporto del gruppo operativo SISMIKO. Sviluppo e mantenimento della rete sismica mobile a seguito del terremoto di Amatrice Mw 6.0 (24 agosto 2016, Italia centrale)

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    La rete sismica temporanea installata dal gruppo operativo INGV SISMIKO a seguito del terremoto del 24 agosto 2016 tra i Monti della Laga e la Valnerina, è stata ampliata nel settore settentrionale a seguito dei forti terremoti avvenuti alla fine del mese di ottobre 2016. Successivamente alle due scosse di Mw 5.4 e 5.9 che il 26 ottobre hanno interessato l’area al confine Marche-Umbria tra i Comuni di Castelsantangelo sul Nera (MC), Norcia (PG) e Arquata del Tronto (AP), la geometria della rete è stata estesa di circa 25 km verso nord con l’attivazione di ulteriori tre stazioni temporanee di cui una, da subito, disposta per la trasmissione dei dati in tempo reale e per l’inserimento nel sistema di sorveglianza sismica dell’Istituto Nazionale di Geofisica e Vulcanologia (INGV). Un’ultima stazione è stata inoltre installata nei pressi di Campello del Clitunno in provincia di Perugia ad ovest della sequenza, a seguito del terremoto Mw 6.5 che la mattina del 30 ottobre ha interessato l’intera area già fortemente provata dalla sequenza in corso; questo è stato il più forte terremoto registrato negli ultimi 30 in Italia. A circa 5 mesi dall’inizio dell’emergenza sismica, la rete temporanea conta quindi 23 stazioni che da metà dicembre sono tutte trasmesse in tempo reale ai diversi centri di acquisizione INGV, ovvero Milano, Ancona e Grottaminarda ma soprattutto Roma dove i dati vengono contestualmente archiviati nell’European Integrated Data Archive (EIDA) e integrati nel sistema di monitoraggio e sorveglianza sismica dell’INGV; per la sorveglianza sono incluse solo parte delle stazioni. Nelle ultime settimane, le attività di campagna del gruppo operativo SISMIKO sono state costantemente focalizzate alla cura e alla manutenzione della strumentazione per garantire la continuità della trasmissione e dell’acquisizione dei dati, a volte compromesse da malfunzionamenti legati al maltempo. Alla data di aggiornamento del presente report, non è ancora stata decretata una dismissione o una rimodulazione della geometria della rete sismica temporanea, anche in considerazione della attività sismica in corso a tutt’oggi molto sostenuta. Tutti i dati acquisiti dalle stazioni temporanee SISMIKO, sono distribuiti senza alcun vincolo, al pari dei dati della Rete Sismica Nazionale (RSN, codice di rete IV), ed utilizzati per prodotti scientifici in tempo reale (localizzazioni di sala, calcolo dei Time Domain Moment Tensor -TDMT delle ShakeMaps, ecc) e per l’aggiornamento dei database dell’INGV come l’Italian Seismological Instrumental and Parametric Database (ISIDe) con la revisione del Bollettino Sismico Italiano (BSI), dell’INGV Strong Motion Data (ISMD) e dell’ITalian ACcelerometric Archive (ITACA), dell’European-Mediterranean Regional Centroid Moment Tensors (RCMT) e nei lavori scientifici che utilizzano forme d’onda velocimetriche ed accelerometriche (ri- localizzazioni, studi della sorgente sismica ecc.).Istituto Nazionale di Geofisica e Vulcanologia (INGV)Published1SR. TERREMOTI - Servizi e ricerca per la Societ

    Le attività del gruppo operativo INGV "SISMIKO" durante la sequenza sismica "Amatrice 2016",

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    SISMIKO è un gruppo operativo dell’Istituto Nazionale di Geofisica e Vulcanologia (INGV) che coordina tutte le Reti Sismiche Mobili INGVPublishedLecce3T. Sorgente sismica4T. Sismicità dell'Italia8T. Sismologia in tempo reale1SR TERREMOTI - Sorveglianza Sismica e Allerta Tsunami2SR TERREMOTI - Gestione delle emergenze sismiche e da maremoto3SR TERREMOTI - Attività dei Centr

    SISMIKO:emergency network deployment and data sharing for the 2016 central Italy seismic sequence

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    At 01:36 UTC (03:36 local time) on August 24th 2016, an earthquake Mw 6.0 struck an extensive sector of the central Apennines (coordinates: latitude 42.70° N, longitude 13.23° E, 8.0 km depth). The earthquake caused about 300 casualties and severe damage to the historical buildings and economic activity in an area located near the borders of the Umbria, Lazio, Abruzzo and Marche regions. The Istituto Nazionale di Geofisica e Vulcanologia (INGV) located in few minutes the hypocenter near Accumoli, a small town in the province of Rieti. In the hours after the quake, dozens of events were recorded by the National Seismic Network (Rete Sismica Nazionale, RSN) of the INGV, many of which had a ML > 3.0. The density and coverage of the RSN in the epicentral area meant the epicenter and magnitude of the main event and subsequent shocks that followed it in the early hours of the seismic sequence were well constrained. However, in order to better constrain the localizations of the aftershock hypocenters, especially the depths, a denser seismic monitoring network was needed. Just after the mainshock, SISMIKO, the coordinating body of the emergency seismic network at INGV, was activated in order to install a temporary seismic network integrated with the existing permanent network in the epicentral area. From August the 24th to the 30th, SISMIKO deployed eighteen seismic stations, generally six components (equipped with both velocimeter and accelerometer), with thirteen of the seismic station transmitting in real-time to the INGV seismic monitoring room in Rome. The design and geometry of the temporary network was decided in consolation with other groups who were deploying seismic stations in the region, namely EMERSITO (a group studying site-effects), and the emergency Italian strong motion network (RAN) managed by the National Civil Protection Department (DPC). Further 25 BB temporary seismic stations were deployed by colleagues of the British Geological Survey (BGS) and the School of Geosciences, University of Edinburgh in collaboration with INGV. All data acquired from SISMIKO stations, are quickly available at the European Integrated Data Archive (EIDA). The data acquired by the SISMIKO stations were included in the preliminary analysis that was performed by the Bollettino Sismico Italiano (BSI), the Centro Nazionale Terremoti (CNT) staff working in Ancona, and the INGV-MI, described below

    Seed priming mitigates high salinity impact on germination of bread wheat (Triticum aestivum L.) by improving carbohydrate and protein mobilization

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    Abstract Salinity is increasingly considered as a major environmental issue, which threatens agricultural production by decreasing yield traits of crops. Seed priming is a useful and cost‐effective technique to alleviate the negative effects of salinity and to enable a fast and uniform germination. In this context, we quantified the effects of priming with gibberellic acid (GP), calcium chloride (CP), and mannitol (MP) on seed germination of three bread wheat cultivars and investigated their response when grown at high salinity conditions (200 mM NaCl). Salt exposure strongly repressed seed imbibition and germination potential and extended germination time, whereas priming enhanced uniformity and seed vigor. Seed preconditioning alleviated the germination disruption caused by salt stress to varying degrees. Priming mitigating effect was agent‐dependent with regard to water status (CP and MP), ionic imbalance (CP), and seed reserve mobilization (GP). Na+ accumulation in seedling tissues significantly impaired carbohydrate and protein mobilization by inhibiting amylase and proteases activities but had lesser effects on primed seeds. CP attenuated ionic imbalance by limiting sodium accumulation. Gibberellic acid was the most effective priming treatment for promoting the germination of wheat seeds under salt stress. Moreover, genotypic differences in wheat response to salinity stress were observed between varieties used in this study. Ardito, the oldest variety, seems to tolerate better salinity in priming‐free conditions; Aubusson resulted the most salt‐sensitive cultivar but showed a high germination recovery under priming conditions; Bologna showed an intermediate behavior

    Sex Differences in the Evaluation of Congestion Markers in Patients with Acute Heart Failure

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    The impact of sex on the assessment of congestion in acute heart failure (AHF) is still a matter of debate. The objective of this analysis was to evaluate sex differences in the evaluation of congestion at admission in patients hospitalized for AHF. We consecutively enrolled 494 AHF patients (252 female). Clinical congestion assessment, B-type natriuretic peptide levels analysis, blood urea nitrogen to creatinine ratio (BUN/Cr), plasma volume status estimate (by means of Duarte or Kaplam-Hakim PVS), and hydration status evaluation through bioimpedance analysis were performed. There was no difference in medications between men and women. Women were older (79 ± 9 yrs vs. 77 ± 10 yrs, p = 0.005), and had higher left ventricular ejection fraction (45 ± 11% vs. 38 ± 11%, p < 0.001), and lower creatinine clearance (42 ± 25 mL/min vs. 47 ± 26 mL/min, p = 0.04). The prevalence of peripheral oedema, orthopnoea, and jugular venous distention were not significantly different between women and men. BUN/Cr (27 ± 9 vs. 23 ± 13, p = 0.04) and plasma volume were higher in women than men (Duarte PVS: 6.0 ± 1.5 dL/g vs. 5.1 ± 1.5 dL/g, p < 0.001; Kaplam–Hakim PVS: 7.9 ± 13% vs. −7.3 ± 12%, p < 0.001). At multivariate logistic regression analysis, female sex was independently associated with BUN/Cr and PVS. Female sex was independently associated with subclinical biomarkers of congestion such as BUN/Cr and PVS in patients with AHF. A sex-guided approach to the correct evaluation of patients with AHF might become the cornerstone for the correct management of these patients

    p38 MAPK differentially controls NK activating ligands at transcriptional and post-transcriptional level on multiple myeloma cells

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    The mechanisms that regulate the expression of the NKG2D and DNAM-1 activating ligands are only partially known, but it is now widely established that their expression is finely regulated at transcriptional, post-transcriptional and post-translational level, and involve numerous stress pathways depending on the type of ligand, stressor, and cell context. We show that treatment of Multiple Myeloma (MM) cells with sub-lethal doses of Vincristine (VCR), an anticancer drug that inhibits the assembly of microtubules, stimulates the expression of NKG2D and DNAM-1 activating ligands, rendering these cells more susceptible to NK cell-mediated killing. Herein, we focused our attention on the identification of the signaling pathways leading to de novo surface expression of ULBP-1, and to MICA and PVR upregulation on VCR-treated MM cells, both at protein and mRNA levels. We found that p38MAPK differentially regulates drug-dependent ligand upregulation at transcriptional and post-transcriptional level. More specifically, we observed that ULBP-1 expression is attributable to both increased transcriptional activity mediated by ATM-dependent p53 activation, and enhanced mRNA stability; while the p38-activated E2F1 transcription factor regulates MICA and PVR mRNA expression. All together, our findings reveal a previously unrecognized activity of VCR as anticancer agent, and indicate that in addition to its established ability to arrest cell growth, VCR can also modulate the expression of NKG2D and DNAM-1 activating ligand on tumor cells and thus promoting NK cell-mediated immunosurveillance
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