Performances of composites made from different recycled carbon fibre semi-products

Recycled carbon fibres (rCF) were generally chosen for their low price and environmental features. However, performances of composites made of recycled carbon fibres are often too low to compete with lightweight alloys and glass fibre composites materials. As performances of rCF composites depend strongly on the fibres architecture, new semi-products with long and aligned recycled carbon fibres were developed by MANIFICA (Cleansky European Project). The use of long (up to 250mm) and highly aligned recycled fibres now provides rCF composites with excellent mechanical properties. The purpose of this work is to assess the performances of composites manufactured with these new rCF semi-products. Semi-products with distinct architectures developed by MANIFICA are first presented. Then mechanical performances of composite plates manufactured from the different semi-products are evaluated. Results are finally compared in order to identify the effect of the manufacturing parameters of the semi-products on the final composite properties. This crucial information will allow end-users to select the right semi-product to design recycled carbon fibre composite innovative parts

Recovery and reuse of discontinuous carbon fibres by solvolysis: Realignment and properties of remanufactured materials

Discontinuous carbon fibre tows were recovered after solvolysis of an aeronautic type composite made with RTM6 epoxy resin. A Sohxlet extraction method was used to quantify the organic residue on the fibre tows and showed that less than 3 wt% was remaining on the surface. The recovered tows were therefore reused directly to manufacture a plate with randomly distributed carbon fibres and then three plates with realigned carbon fibres. The latter were then characterised and tested and the results obtained were compared to the material manufactured using the same type of virgin fibres by the same method. The materials made from recycled carbon fibres showed very good properties in comparison to the virgin fibre material, despite the presence of flaws such as quality of the fibre surface after solvolysis, alignment and voids). This is the first time in the open literature that carbon fibres recovered from solvolysis were reused in this way together with characterisation of the resulting materials

Simplification of requalification procedure of outdated carbon/epoxy prepregs and scenarios of reuse

As a result of their combined high mechanical performances and easy processability, carbon/epoxy prepregs are widely used in the manufacture of aerostructures. The resin of these materials is in an intermediate state of polymerisation which makes these materials perishable. Drastic manufacture conditions lead continuously to the generation of expired prepregs that, today, can no more be used in the aeronautic industry nor in other industries. Although requalification procedure can be carried out, its high cost does not always justify such a procedure. This is why large quantities of expired prepregs are send to landfill. The objective of the Cleansky project MANIFICA is to set up a complete recycling chain of carbon fibre composites “from aeronautic waste to innovative composite parts”. The aim of this work is to propose a simplified requalification procedure by avoiding unnecessary tests. These studies are illustrated by property measures on compliant and expired prepregs. The main results were that in most cases, aging induces processing difficulties while mechanical performance remains unaffected. It was also shown that a simpler requalification procedure was possible and that expired prepregs can be reused without loss of performance outside the aeronautical field. Rather than considering expired material as waste, MANIFICA offers several new reuse scenario

Interaction microstructure/propriétés dans un matériau composite à fibres de carbone recyclées

Il existe aujourd’hui plusieurs techniques efficaces de séparation fibres / matrice pour recycler les fibres de carbone issues de matériaux composites. Les projets de développement de ces techniques thermiques, fluides supercritiques ou chimiques ont donné d’excellents résultats (RECCOMP, HIRECAR, Aerdeco, RECCO), voire [1], [2]. Les techniques les plus efficaces permettent d’obtenir des fibres de carbone de 2° génération avec une très faible perte de propriété (inférieure à 5%) [3], [4]. Le réalignement des fibres recyclées s’avère un point clé dans l’obtention de nouveaux matériaux composites utilisables pour des applications structurelles à forte valeur ajoutée. A ce titre, nous présenterons dans une première partie, un procédé innovant de remise en forme inventé à l’I2M de Bordeaux qui génère des semi-produits de fibres de carbone de 2° génération à partir de morceaux de tissus de carbone post-solvolyse. Dans une seconde partie, nous étudions l’impact de la nature des fibres, du taux de réalignement et de la dispersion de la densité sur la résistance des matériaux composites de 2° génération (contenant des fibres recyclées remises en forme). La maîtrise des relations paramètres de remise en forme qualité du semi-produit résistance du matériau recyclé permettra alors d’envisager des applications structurales pour de la fibre de carbone recyclée. La conclusion de cette présentation est qu’il est impératif d’étudier les facettes chimiques (séparation fibre/matrice) et mécaniques (remise en forme des fibres solvolysées) du recyclage pour concevoir des semi-produits de fibres recyclées et ouvrir les voies d’une utilisation de haute qualité des fibres recyclées. Références : [1] Soraia Pimenta, Silvestre T. Pinho “Recycling carbon fibre reinforced polymers for structural applications: Technology review and market outlook” Waste Management 31 (2011) 378–392 [2] Carbon recycling: a soluble problem » REINFORCED plastics MAY 2009 [3] S.J. Pickering “Recycling technologies for thermoset composite materials—current status” Composites: Part A 37 (2006) 1206–1215 [4] Yongxiang Yang, Rob Boom, Brijan Irion, Derk-Jan van Heerden, Pieter Kuiper, Hans de Wit “Recycling of composite materials” Chemical Engineering and Processing 51 (2012) 53– 6

PROPHYLACTIC EVALUATION OF SHOULDER PROPRIOCEPTION IN ELITE SWIMMERS

It is suggested that poor shoulder proprioception contributes to shoulder pain in swimmers. However, there is a lack of studies describing the measurement method for shoulder proprioception. The purposes of this preliminary study was to investigate the scapular position depending on arm scaption as a first step in the development of a measurement method for three-dimensional shoulder proprioception. An asymptomatic young adults participated in this study. His scapular rotation were measured as a function of arm position during scaption in two consecutive days. The results showed that scapular rotations are not a reproducible function of humerus elevation. Those findings suggested that the assessement of shoulder proprioception should rely on the evaluation of both gleno-humeral and scapulo-thoracic joints to be valid

A life-attenuated BLV deletant as a candidate vaccine to inhibit viral transmission in bovine herds

A life-attenuated BLV deletant as a candidate vaccine to inhibit viral transmission in bovine herds Sabrina M. Rodríguez1*†, Gerónimo Gutiérrez2*, Arnaud Florins3, Lucas Vagnoni2, Irene Alvarez2, Nicolas Gillet1, Karina Trono2‡, Luc Willems1,3‡ *‡S.M. Rodríguez / G. Gutiérrez and K.Trono / L. Willems contributed equally to this work. 1 Molecular and Cellular Epigenetics, Interdisciplinary Cluster for Applied Genoproteomics (GIGA), University of Liège (ULg), Liège (4100), Belgium. 2 Instituto de Virología, CICVyA, Instituto Nacional de Tecnología Agropecuaria, (1712), Castelar, Argentina. 3 Molecular and Cellular Biology, Gembloux Agro-Bio Tech, University of Liège (ULg), Gembloux (5030), Belgium †E-mail: [email protected] Bovine Leukemia Virus (BLV) is a major sanitary concern in many countries where the virus is widely disseminated among dairy herds with obvious economic impact. Different control strategies have been implemented worldwide to control BLV infection or eradicate the disease with diverse success. Eradication by culling is not economically sustainable in highly infected regions such as Argentina, US or Japan. Segregation of BLV-infected cattle is expensive due to duplication of facilities. Finally, several candidate vaccines based on recombinant viral proteins were unsuccessful to protect from challenge. Therefore, here we propose a novel strategy aimed to decrease seroprevalence based on the employ of a life-attenuated BLV provirus as a candidate vaccine. The rationale behind this strategy is the deletion of genes required to induce pathogenesis leaving those involved in infectivity, resulting in an attenuated deletant with impaired transmissibility. Preliminary experiments showed that the deletant provirus is infectious and elicits an efficient immune response in sheep (n=3) and in the natural host, bovines (n=9). Lack of spread to sentinels further supports the safety of the vaccine. Based on these promissory results, an ongoing validation program is being performed to evaluate the capacity of the candidate vaccine to protect from wild-type BLV infection in herd conditions (n=105). Infection will be routinely monitored and proviral loads will be determined. The efficiency of the immune response will be evaluated by titration of specific antibodies, cytotoxic lysis efficiency and cytokine profile. Viral expression ex vivo and provirus clonality will be also evaluated. This data will be instrumental for understanding the basic mechanisms undergoing during BLV infection and for elaborating a novel vaccine. We do believe this practical and cost-effective vaccination strategy is the sole economically viable in countries with high prevalence

Nacre, a natural, multi-use, and timely biomaterial for bone graft substitution

International audienceDuring the past two decades, with a huge and rapidly increasing clinical need for bone regeneration and repair, bone substitutes are more and more seen as a potential solution. Major innovation efforts are being made to develop such substitutes , some having advanced even to clinical practice. It is now time to turn to natural biomaterials. Nacre, or mother-of-pearl, is an organic matrix-calcium carbonate coupled shell structure produced by molluscs. In vivo and in vitro studies have revealed that nacre is osteoinductive, osteoconductive, biocompatible, and biodegradable. With many other outstanding qualities, nacre represents a natural and multi-use biomaterial as a bone graft substitute. This review aims at summarising the current needs in orthopaedic clinics and the challenges for the development of bone substitutes; most of all, we systematically review the physiological characteristics and biological evidence of nacre's effects centred on osteogen-esis, and finally we put forward the potential use of nacre as a bone graft substitute

Mechanisms of leukemogenesis induced by bovine leukemia virus: prospects for novel anti-retroviral therapies in human

In 1871, the observation of yellowish nodules in the enlarged spleen of a cow was considered to be the first reported case of bovine leukemia. The etiological agent of this lymphoproliferative disease, bovine leukemia virus (BLV), belongs to the deltaretrovirus genus which also includes the related human T-lymphotropic virus type 1 (HTLV-1). This review summarizes current knowledge of this viral system, which is important as a model for leukemogenesis. Recently, the BLV model has also cast light onto novel prospects for therapies of HTLV induced diseases, for which no satisfactory treatment exists so far

Preventive and Therapeutic Strategies for Bovine Leukemia Virus: Lessons for HTLV

Bovine leukemia virus (BLV) is a retrovirus closely related to the human T-lymphotropic virus type 1 (HTLV-1). BLV is a major animal health problem worldwide causing important economic losses. A series of attempts were developed to reduce prevalence, chiefly by eradication of infected cattle, segregation of BLV-free animals and vaccination. Although having been instrumental in regions such as the EU, these strategies were unsuccessful elsewhere mainly due to economic costs, management restrictions and lack of an efficient vaccine. This review, which summarizes the different attempts previously developed to decrease seroprevalence of BLV, may be informative for management of HTLV-1 infection. We also propose a new approach based on competitive infection with virus deletants aiming at reducing proviral loads

Assessment of Fish Abundance, Biodiversity and Movement Periodicity Changes in a Large River over a 20-Year Period

peer reviewedA river is an ecosystem where fish fauna represents an important structural element. To re-establish connectivity, it is imperative to allow movement between functional habitats. Due to the hydromorphological complexity of large anthropized rivers and the lack of study techniques that can be used in such environments, relevant data with regard to fish ecology are scarce. On the River Meuse, Belgium, at a point 323 km upstream from the North Sea, the Lixhe hydroelectric dam is equipped with two fishways. Both were continuously monitored using capture traps for 20 consecutive years (from 1999 to 2018), representing 4151 monitoring events. The objectives of the present study were to describe the overall abundance and movement indicators of mainly holobiotic potamodromous fish species and to analyse their temporal evolution. We captured 388,631 individuals (n = 35 fish species) during the 20 years of fishway monitoring; 22.7% were adults (>75% of which were cyprinids), and 83.3% juveniles (>90% cyprinids). From 1999 to 2018, the results showed a drastic reduction in yearly captures for some native species as well as the apparent emergence of non-native (e.g., Silurus glanis) and reintroduced species (e.g., Salmo salar). The annual capture periodicities associated with environmental factors were clearly defined and were mostly related to the spring spawning migration of the adult stage. This long-term monitoring demonstrated how the fishways are used by the whole fish community and allowed a better understanding of their movement ecology in a large lowland anthropized river. The appearance of non-native species and the drastic decline in abundance of some common and widespread European fish should prompt river managers to adopt conservation measures.Programme Saumo