2,960 research outputs found

    Natural Fiber-Reinforced Hybrid Composites

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    In the last few decades, natural fibers have received growing attention as an alternative to the synthetic fibers used in the reinforcement of polymeric composites, thanks to their specific properties, low price, health advantages, renewability, and recyclability. Furthermore, natural fibers have a CO2-neutral life cycle, in contrast to their synthetic counterparts. As is widely known, natural fibers also possess some drawbacks, e.g., a hydrophilic nature, low and variable mechanical properties, poor adhesion to polymeric matrices, high susceptibility to moisture absorption, low aging resistance, etc. This implies that their applications are limited to non-structural interior products. To overcome this problem, the hybridization of natural fibers with synthetic ones (i.e., glass, carbon, and basalt) or different natural fibers can be a solution. For this reason, extensive research concerning natural–synthetic and natural–natural hybrid composites has been done in the last years. In this context, this book aims to collect some interesting papers concerning the use of natural fibers together with synthetic ones with the aim of obtaining hybrid structures with good compromise between high properties (e.g., mechanical performances, thermal behavior, aging tolerance in humid or aggressive environments, and so on) and environment care

    Correction:Carbonyl trapping and antiglycative activities of olive oil mill wastewater

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    Correction for ‘Carbonyl trapping and antiglycative activities of olive oil mill wastewater’ by Marta Navarro et al., Food Funct., 2015, 6, 574–583

    Quantification of Nε-(2-Furoylmethyl)-L-lysine (furosine), Nε-(Carboxymethyl)-L-lysine (CML), Nε-(Carboxyethyl)-L-lysine (CEL) and total lysine through stable isotope dilution assay and tandem mass spectrometry

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    The control of Maillard reaction (MR) is a key point to ensure processed foods quality. Due to the presence of a primary amino group on its side chain, lysine is particularly prone to chemical modifications with the formation of Amadori products (AP), Nε-(Carboxymethyl)-L-lysine (CML), Nε-(Carboxyethyl)-L-lysine (CEL). A new analytical strategy was proposed which allowed to simultaneously quantify lysine, CML, CEL and the Nε-(2-Furoylmethyl)-L-lysine (furosine), the indirect marker of AP. The procedure is based on stable isotope dilution assay followed by, liquid chromatography tandem mass spectrometry. It showed high sensitivity and good reproducibility and repeatability in different foods. The limit of detection and the RSD% were lower than 5 ppb and below 8%, respectively. Results obtained with the new procedure not only improved the knowledge about the reliability of thermal treatment markers, but also defined new insights in the relationship between Maillard reaction products and their precursors

    Recovery of Waste Polyurethane from E-Waste. Part II. Investigation of the Adsorption Potential for Wastewater Treatment

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    This study explored the performances of waste polyurethane foam (PUF) derived from the shredding of end-of-life refrigerators as an adsorbent for wastewater treatment. The waste PUF underwent a basic pre-treatment (e.g., sieving and washing) prior the adsorption tests. Three target pollutants were considered: methylene blue, phenol, and mercury. Adsorption batch tests were performed putting in contact waste PUF with aqueous solutions of the three pollutants at a solid/liquid ratio equal to 25 g/L. A commercial activated carbon (AC) was considered for comparison. The contact time necessary to reach the adsorption equilibrium was in the range of 60–140 min for waste PUF, while AC needed about 30 min. The results of the adsorption tests showed a better fit of the Freundlich isotherm model (R2 = 0.93 for all pollutants) compared to the Langmuir model. The adsorption capacity of waste PUF was limited for methylene blue and mercury (Kf = 0.02), and much lower for phenol (Kf = 0.001). The removal efficiency achieved by waste PUF was lower (phenol 12% and methylene blue and mercury 37–38%) compared to AC (64–99%). The preliminary results obtained in this study can support the application of additional pre-treatments aimed to overcome the adsorption limits of the waste PUF, and it could be applied for “rough-cut” wastewater treatment

    Recovery of Waste Polyurethane from E-Waste—Part I: Investigation of the Oil Sorption Potential

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    The shredding of end-of-life refrigerators produces every year in Italy 15,000 tons of waste polyurethane foam (PUF), usually destined for energy recovery. This work presents the results of the investigation of the oil sorption potential of waste PUF according to ASTM F726–17 standard. Three oils (diesel fuel and two commercial motor oils) having different densities (respectively, 0.83, 0.87, and 0.88 kg/dm3) and viscosities (respectively, 3, 95, and 140 mm2/s at 40 C) were considered. The waste PUF was sampled in an Italian e-waste treatment plant, and its characterization showed 16.5 wt% particles below 0.71 mm and 13 wt% impurities (paper, plastic, aluminum foil), mostly having dimensions (d) above 5 mm. Sieving at 0.071 mm was applied to the waste PUF to obtain a “coarse” (d > 0.71 mm) and a “fine” fraction (d < 0.71 mm). Second sieving at 5 mm allowed an “intermediate” fraction to be obtained, with dimensions between 0.71 and 5 mm. The oil sorption tests involved the three fractions of waste PUF, and their performances were compared with two commercial oil sorbents (sepiolite and OKO-PUR). The results of the tests showed that the “fine” PUF was able to retain 7.1–10.3 g oil/g, the “intermediate” PUF, 4.2–7.4 g oil/g, and the “coarse” PUF, 4.5–7.0 g oil/g, while sepiolite and OKO-PUR performed worse (respectively, 1.3–1.6 and 3.3–5.3 g oil/g). In conclusion, compared with the actual management of waste PUF (100 wt% sent to energy recovery), the amount destined directly to energy recovery could be limited to 13 wt% (i.e., the impurities). The remaining 87 wt% could be diverted to reuse for oil sorption, and afterward directed to energy recovery, considered as a secondary option

    Evolution of protein bound Maillard reaction end-products and free Amadori compounds in low lactose milk in presence of fructosamine oxidase I

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    Thermal treatments and storage influence milk quality, particularly in low lactose milk as the higher concentration of reducing sugars can lead to the increased formation of the Maillard reaction products (MRPs). The control of the Amadori products (APs) formation is the key step to mitigate the Maillard reaction (MR) in milk. The use of fructosamine oxidases, (Faox) provided promising results. In this paper, the effects of Faox I were evaluated by monitoring the concentration of free and bound MRPs in low lactose milk during shelf life. Results showed that the enzyme reduced the formation of protein-bound MRPs down to 79% after six days at 37 °C. Faox I lowered the glycation of almost all the free amino acids resulting effective on basic and polar amino acids. Data here reported corroborate previous findings on the potentiality of Faox enzymes in controlling the early stage of the MR in foods

    LA PREFAZIONE AL CONTE DI CARMAGNOLA DI ALESSANDRO MANZONI

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    Il saggio ripercorre con metodo filologico le date della composizione della tragedia Il Conte di Carmagnola da parte di Alessandro Manzoni, soffermandosi sulla stesura pressoché contemporanea dei Materiali estetici preparatori ad un mai realizzato Discorso della moralità delle opere tragiche, e i cui punti salienti sarebbero confluiti nella Lettre à M. Chauvet e, prima ancora, nella Prefazione al Conte di Carmagnola. Ed è di quest’ultimo testo che il contributo, con un metodo analitico sinottico che rinvia costantemente ai riscontri dell’epistolario e di altre opere, propone una lettura che pone il Manzoni in contrasto sia con August Wilhelm Schlegel e la filosofia tedesca, sia con il gruppo del “Conciliatore” e smentisce l’accostamento della teoria drammatica manzoniana alla teoria di Bertolt Brecht operato da una parte della critica. Il saggio rinviene la peculiarità della poetica manzoniana nella centralità del lettore, idealmente inscindibile dall’autore e dalla materia della tragedia in quanto espressioni di una morale comune espressa dalla fede cattolica e operante nella storia per mezzo della provvidenza. Si tratta di un idealismo religioso molto diverso dall’idealismo tedesco dello Schlegel e del circolo filosofico di Jena, e della fondazione di un teatro storico nettamente in contrasto con il teatro borghese di Lessing, che fa del Manzoni l’interprete della nascente coscienza nazionale italiana.Publishe

    Alessandro Manzoni: „rzeczywiste” i „możliwe” w dialogu wynalazków

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    The author analyzes Alessandro Manzoni's dialogue Dell’invenzione and shows the close dependence of this work on the philosophy of Antonio Rosmini and that this philosophical dialogue, often underestimated by literary criticism, is poetically inseparable not only from the Discorso del romanzo storico, published in 1850 as well, but also from the Storia della colonna infame, the pamphlet on the trials of the anointers arrested in Milan in the aftermath of the 1630 plague, that Manzoni published at the end of The bethrothed’s 1840-42 version.Il dialogo Dell’invenzione, pubblicato nel 1850, sembra a prima vista del tutto estraneo all’arco della quasi quarantennale riflessione teorica manzoniana, che sul tema del rapporto fra storia e invenzione, dai cosiddetti Materiali estetici al Discorso del romanzo storico, sfugge sia all’ambito del formularismo pragmatico classicista sia all’opposta opzione romantica. Tale visione critica può intervenire a relegare il dialogo manzoniano al puro settore dei suoi scritti filosofici, e dunque a considerarlo di interesse minore, proprio per il suo oggetto, che è l’ontologia e la gnoseologia rosminiana, discussa dai tre personaggi fittizi di Primo, Secondo e Terzo.Autor analizuje dialog Alessandra Manzoniego Dell'invenzione i ukazuje ścisłą zależność tego dzieła od filozofii Antonio Rosminiego oraz to, że ów filozoficzny dialog, często niedoceniany przez krytykę literacką, jest poetycko nierozłączny nie tylko z Discorso del romanzo storico, opublikowanym również w 1850 r., ale także ze „Storia della colonna infame”, broszurą na temat procesów namaszczających, aresztowanych w Mediolanie w następstwie dżumy z 1630 r., którą Manzoni opublikował na końcu „Narzeczonych” w wersji z 1840-42

    Mechanical behavior of carbon/flax hybrid composites for structural applications

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    In this work, the influence of an unidirectional carbon fabric layer on the mechanical performances of bidirectional flax fabric/epoxy composites used for structural applications was studied. Two different bidirectional flax fabrics were used to produce flax fabric reinforced plastic (FFRP) laminates by a vacuum bagging process: one is normally used to make curtains; the other, heavier and more expensive than the previous one, is usually used as reinforcement in composite structures. In order to realize hybrid structures starting from FFRP, an unidirectional UHM carbon fabric was used to replace a bidirectional flax fabric. Tensile and three-point bending tests were performed to evaluate the mechanical properties of the laminates investigated (both FFRP and hybrids). Furthermore, the mechanical behavior of the different bidirectional flax fabrics was analyzed by carrying out tensile tests. The experimental tests showed that the structures reinforced with flax fabrics, normally used to make curtains, present better flexural properties than that of others while, in tensile configuration, these last show higher modulus and strength. Moreover, both FFRP laminates show low mechanical properties, which do not allow their use in structural applications while the presence of one external layer of unidirectional carbon involves remarkable increase in their properties. According to this study, the hybrid composites realized could be used in several structural applications (i.e., nautical and automotive)

    Addiction beyond pharmacological effects: The role of environment complexity and bounded rationality

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    Several decision-making vulnerabilities have been identified as underlying causes for addictive behaviours, or the repeated execution of stereotyped actions despite their adverse consequences. These vulnerabilities are mostly associated with brain alterations caused by the consumption of substances of abuse. However, addiction can also happen in the absence of a pharmacological component, such as seen in pathological gambling and videogaming. We use a new reinforcement learning model to highlight a previously neglected vulnerability that we suggest interacts with those already identified, whilst playing a prominent role in non-pharmacological forms of addiction. Specifically, we show that a dual-learning system (i.e. combining model-based and model-free) can be vulnerable to highly rewarding, but suboptimal actions, that are followed by a complex ramification of stochastic adverse effects. This phenomenon is caused by the overload of the capabilities of an agent, as time and cognitive resources required for exploration, deliberation, situation recognition, and habit formation, all increase as a function of the depth and richness of detail of an environment. Furthermore, the cognitive overload can be aggravated due to alterations (e.g. caused by stress) in the bounded rationality, i.e. the limited amount of resources available for the model-based component, in turn increasing the agent’s chances to develop or maintain addictive behaviours. Our study demonstrates that, independent of drug consumption, addictive behaviours can arise in the interaction between the environmental complexity and the biologically finite resources available to explore and represent it
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