255 research outputs found

    Grinding, Melting and Reshaping of EoL Thermoplastic Polymers Reinforced with Recycled Carbon Fibers

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    This article assesses the technical feasibility of a recycling process based on grinding, melting and re-shaping of carbon fibers (CFs) reinforced thermoplastic polymers, in order to obtain new products that can be introduced in different markets, depending on mechanical properties retained. The idea at the basis of our study is that this kind of recycling process lies at the edge of the stages of recycling and re-use of materials, considering that the latter is preferable when considering the waste management hierarchy. Lower cost and similar mechanical strength of virgin CFs allowed the spread of recycled CFs in the automotive sector in the form of composite materials. Taking into account the Directive 2000/53/EC that sets out measures to prevent and limit waste from end-of-life (EoL) vehicles and their components, and ensures that where possible this is reused, recycled or recovered, we considered worth to investigate the recyclability of composite materials made with recycled CFs when they will reach the state of EoL materials. Considering this premise, an additional scope of this paper is therefore to provide some useful information about the possibility to perform a multiple closed loop recycling of rCF thermoplastic composites. Experiments carried out demonstrated that re-shaping of composites is technically feasible. Some square plates were produced without any setback. The mass balance of the recycling process demonstrated that about 88% of the EoL material can be recovered. Calculation of energy consumption showed that approximately 16 MJ are necessary in the treatment of 1 kg of EoL composites

    Characterization of Composites Manufactured Through Reshaping of EoL Thermoplastic Polymers Reinforced with Recycled Carbon Fibers

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    This article investigates if and at what extent a recycling process based on grinding, melting and re-shaping of recycled carbon fibers reinforced thermoplastic polymers (rCFRPs) can affect their physical, mechanical and thermal properties. The aim is to establish if they can be taken into consideration in the manufacturing of new composite materials in different sectors: automotive, marine, sporting goods, etc. Composites materials were submitted to the measurement of the fibers length they are composed of, and then analyzed by means of tensile and impact tests and a dynamic mechanical analysis (DMA). All the characterizations were performed to both initial and recycled composites and, in some cases, they were replied also after the intermediate accelerated aging. Characterization performed confirmed that, as expected, the recycling process affects the properties of the composites, but in different manners and to a different extent when different polymers are involved. Tensile and impact tests pointed out that the polypropylene based composites showed a less stiff and a more brittle behaviour after the recycling process and the DMA confirmed this evidence, highlighting in addition a more viscous behavior of the polymer after the recycling. Conversely, the polyamide 6 based composites increased their stiffness and ductility after the recycling. For all the composites the tensile strength dropped, confirming the weakening of the materials

    Genome-wide identification of wrky genes in artemisia annua: Characterization of a putative ortholog of ATWRKY40

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    Artemisia annua L. is well-known as the plant source of artemisinin, a sesquiterpene lactone with effective antimalarial activity. Here, a putative ortholog of the Arabidopsis thaliana WRKY40 transcription factor (TF) was isolated via reverse transcription-polymerase chain reaction and rapid amplification of cDNA ends in A. annua and named AaWRKY40. A putative nuclear localization domain was identified in silico and experimentally confirmed by using protoplasts of A. annua transiently transformed with AaWRKY40-GFP. A genome-wide analysis identified 122 WRKY genes in A. annua, and a manually curated database was obtained. The deduced proteins were categorized into the major WRKY groups, with group IIa containing eight WRKY members including AaWRKY40. Protein motifs, gene structure, and promoter regions of group IIa WRKY TFs of A. annua were characterized. The promoter region of AaWRKY group IIa genes contained several abiotic stress cis-acting regulatory elements, among which a highly conserved W-box motif was identified. Expression analysis of AaWRKY40 compared to AaWRKY1 in A. annua cell cultures treated with methyl jasmonate known to enhance artemisinin production, suggested a possible involvement of AaWRKY40 in terpenoid metabolism. Further investigation is necessary to study the role of AaWRKY40 and possible interactions with other TFs in A. annua

    Aluminum Nitride piezo-MEMS on polyimide flexible substrates

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    In this work the micro-fabrication of flexible MicroElectroMechanical transducers based on the piezoelectric effect is reported. We developed the technological protocol to realize a piezoelectric transducer composed by a Molybdenum (Mo) top electrode, the Aluminum Nitride active layer and a Mo bottom electrode on a polymeric tape. The process starts from the DC sputtering deposition of the Molybdenum layer at room temperature on Kapton HN. The Molybdenum is chosen not only for its electrical properties but also because it enhances the crystal orientation of AlN. The next step is the deposition of AlN that occurs at high temperature, around 250^oC. Temperature and physical sputtering enhanced by applying a DC bias on the substrates are two important parameters to improve the crystal orientation of the film. These extreme growth conditions guarantee a very good crystal structure without damaging the Kapton substrate. Then a final Mo layer is sputtered at room temperature. SU8-25 thick photo resist is used to define the top electrode and the AlN layer, and in a second mask step the Mo bottom electrode. The developer, the PG remover and SU8 negative resist itself have shown a chemical compatibility with Kapton HN. We measured the piezoelectric response on a capacitor test structure: through the Dynamic Mechanical Analyzer we applied controlled forces, and at the same time, by an LCR meter we performed measurements of the capacitance

    Lymphatic Function of the Lower Limb after Groin Dissection for Vulvar Cancer and Reconstruction with Lymphatic SCIP Flap

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    Inguinofemoral lymphadenectomy, frequently performed for vulvar cancer, is burdened with substantial immediate and long-term morbidity. One of the most disabling treatment-related sequelae is lower limb lymphedema (LLL). The present study aims to describe the wound complications and the severity of LLL in patients who have undergone groin dissection for vulvar cancer and immediate inguinal reconstruction with the Lymphatic Superficial Circumflex Iliac Perforator flap (L-SCIP). We retrospectively reviewed the data of patients who underwent bilateral groin dissection and unilateral inguinal reconstruction with the L-SCIP. The presence and severity of postoperative LLL during the follow-up period were assessed by lymphoscintigraphy and limbs’ volume mea-surement. In addition, immediate complications at the level of the inguinal area were registered. The changes between preoperative and postoperative limb volumes were analyzed by Student’s t test. p values < 0.05 were considered significant. Thirty-one patients were included. The mean variation of volume was 479 ± 330 cc3 in the side where groin reconstruction had been performed, and 683 ± 425 cc3 in the contralateral side, showing smaller variation in the treated side (p = 0.022). Lymphoscintigraphy confirmed the clinical findings. Based on our results, inguinal reconstruction with L-SCIP performed at the same time of groin dissection in patients treated for vulvar cancer can provide a significant protective effect on LLL

    Phosphonium ionic liquids (PILs) as organocatalysts for green reactions: nucleophilic electrophilic cooperative catalysis

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    With the aim of developing a green synthesis of phosphonium ionic liquids (PILs), we prepared a series of methyltrialkylphosphonium methyl carbonates [Pn,n,n,1]+[O(CO)OCH3]- by the alkylation of trialkylphosphines with the non toxic dimethylcarbonate. These compounds proved to be active organocatalysts for a number of base-promoted organic reactions such as Michael, Henry, and Baylis-Hillman condensations, and transesterification reactions. In addition methyl carbonate salts were a convenient starting material to synthesise a large array of ionic liquids where the phosphonium cation was coupled to weakly basic anions such as bicarbonate, acetate, trifluoroacetate, phenate, chloride, bromide and many more. Mechanistic studies indicated that the anionic and the cationic partners of such ionic liquids acted cooperatively and independently as nucleophilic and electrophilic catalysts. The ambiphilic propensity of these salts was demonstrated by kinetically discriminating the contributions of the anion (nucleophilic catalyst) and of the cation (electrophilic catalyst) on the model solvent-free Baylis–Hillman dimerization of cyclohexenone

    The European Association for the Study of Obesity (EASO) Endorses the Milan Charter on Urban Obesity

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    The Milan Charter on Urban Obesity highlights the challenges of urban environments as a battleground for human health, as cities are often organized to subvert public health goals, and promote rather than prevent the development of obesity and consequent non-communicable diseases. The Charter articulates ten principles which detail actions and strategies through which general practitioners, diverse medical specialists, related healthcare professionals, administrators and healthcare practice managers, policy actors - within health systems and at a national level - along with experts across disciplines, and citizens, can work in cooperation to meet this challenge and improve publichealth. The Charter urges the adoption of decisions that deliver the following: (i) policies which enable our cities to become healthier and less obesogenic, more supportive of well-being and less health-disruptive in general, and (ii) policies that fully support primary prevention strategies, that address social stigma, and that ensure fair access to treatment for people living with obesity. The Milan Charter on Urban Obesity aims to raise awareness of our shared responsibility for the health of all citizens, and focuses on addressing the health of people living with obesity - not only as a challenge in its own right, but a gateway to other major non-communicable diseases, including cardiovascular diseases, type 2 diabetes, and some cancers
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