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Managing landfill waste is essential to sustainable resource utilization. With a focus on the luxury fashion industry, this paper highlights the role that sustainable and social innovations can play in reducing environmental waste and improving social outcomes. Elvis & Kresse is a purpose-driven case study, because it was founded to eradicate a problem that had thus far received little attention, namely the problem of disposing of end-of-life fire-hoses. From a business model and circular economy perspective, this article explains how the company’s rescue–transform–donate model has helped to build a sustainable and socially oriented yet profitable luxury brand. The analysis of the case suggests that for scholars, the typical business model canvas merits some revision beyond the current business focus on the financial bottom line to account for the social and ethical dimensions. For practitioners, this case demonstrates how the circular economy can be compatible with luxury fashion by turning waste into durable, fashionable products.

Blockchain, often known as the Internet of Value, is a new technology. And like many other new technologies, no one knows it’s potential, many claims that it’s going to revolutionize the way we live. It will deliver more radical changes than the Internet, with some questioning its significance. Despite dire predictions, blockchain is a game changing, new technology that have the ability to revolutionize the way people conduct business because of its ability to ensure security. The immutability of records is ensured by confidence among unknown individuals, while intermediaries are excluded. The popularity of digital currency, the enormous number of published blockchain studies, all attest to blockchain's importance. This paper provides an overview of blockchain, a rapidly emerging topic that discusses its benefits and downsides, as well as their potential consequences on the Internet, and societies in general.

International audience; Highly fluorinated fullerenes with a chemical composition of C60F48 have been prepared and characterized. Their solubility of the new nanomaterials in the ionic liquid (IL) has been compared with raw fullerenes C60. Fluorination may appear as a convenient method to enhance the solubility of carbonaceous nanomaterials in a fluorinated based anion IL. Indeed, the ability of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([BmIm][NTf2]), to solubilize C60 and C60F48 was investigated using optical microscopy and UV–vis spectroscopy. While C60 has very poor solubility in this IL (below 0.07 mmol/L), the solubility increases at least eightfold, i.e. more than 1.0 mg/mL (or 0.61 mmol/L) for C60F48 samples. The presence of fluorine atoms on fullerene seems to enhance the stability of the solvated molecules in IL thanks to the limitation of the aggregation of C60F48 in [BmIm][NTf2]. This improvement of the solubility could be explained by the beneficial effect of the fluorination that induces a decrease of the π-π interaction between carbonaceous solutes as the carbon hybridization changes from sp2 to sp3 through the formation of C-F covalent bonds and thus enhances the interaction between the solvent and the solute. Fluorination appears as an efficient approach to limit the use of volatile organic compounds usually used as co-solvent to enhance the dispersion mechanism.

International audience; The present review focuses on the numerous routes for the preparation of fluorinated graphene (FG) according to the starting materials. Two strategies are considered: (i) addition of fluorine atoms on graphenes of various nature and quality and (ii) exfoliation of graphite fluoride. Chemical bonding in fluorinated graphene, related properties and a selection of applications for lubrication, energy storage, and gas sensing will then be discussed.

The present work introduces a safe and efficient fluorination method, called RT-pulsed fluorination, proceeding under pure fluorine gas. The RT-pulsed fluorination enables to modify the surface chemistry of carbon aerogels (CAs), materials which suffer from water trapping into their porosity and their low degree of graphitization, hence limiting their application. This new fluorination route was developed to reach several goals, such as preventing the generation of structural defects, maintaining the tailored porous texture of the aerogel, favoring covalent C–F bonding without promoting CF2 and CF3 groups, and repulsing the water trapping into the porosity. The impact of the RT-pulsed fluorination on the conductivity will be also discussed.

Composite waste, especially from wind turbine blades will increase foreseeably. Themotivation of this paper is to develop new solutions to repurpose the global material stream coming from wind turbine blades at their end of use. Its suggested to use the composite structure for repurposing, differing from the available recycling methods that aim for a separation of the composite into fibre and matrix fractions. One key factor towards circularity in composite materials is converting significant amounts of composite material into multiple meaningful applications and products. Industry 4.0 can offer a systemic solution utilising robots and digital tools, such as a digital twin of a composite wind turbine blade. The digital handling of relevant material information can offer a new affordable material source to multiple industries, such as building industry or manufacturing businesses. Based on a digital platform the composite material can be made available for architects, designers and developers to repurpose compositesinto multiple new products.

Nanostructured carbons were fluorinated and used as supports for Pt nanoparticles deposition using a modified polyol route. The resulting materials exhibited similar Pt nanoparticles sizes, but different agglomeration rates. The electrocatalysts were tested toward the oxygen reduction reaction, and their stability was investigated in simulated load cycling (0.6 < E < 1.0 V vs. RHE) or start-up/shutdown (1.0 < E < 1.5 V vs. RHE) protocols. Irrespective the support material, the former protocol caused Pt nanocrystallites dissolution/redeposition via Ostwald ripening, mildly decreasing the electrochemically-active surface area and ORR activity. In contrast, the carbon supports were strongly corroded after the start-up/shutdown protocol, resulting in pronounced detachment/agglomeration of Pt nanocrystallites, albeit in absence of significant particle-size growth. Fluorination had different effects on the stability of structurally-ordered and structurally-disordered carbons: beneficial effects were observed for the latter whereas the former was affected negatively. “Free” dangling groups present in structurally-disordered carbon, known to be prone to preferential oxidation in PEMFC environment, combine with the fluorine precursors upon fluorination, leading to formation of more robust C-F bonds versus oxidation than original C-O bonds. In contrast, fluorination of structurally-ordered carbon creates structural disorder (C-C bonds are broken), leading to promotion of electrochemical corrosion.

International audience; An attempt has been made to review and analyze the developments made during last few decades on the place of carbon in batteries. First identified as an anode of interest in the form of graphite, carbon has also made a place for itself as conductive agent added during electrode formulation or also as buffer with electrochemical active oxide processing by conversion. The focus is primarily on how to decrease the irreversibility of classical anode materials then how to increase its whole performance through nanostructures, mainly CNTs and graphene. We have identified post-lithium batteries as an opportunity for carbon as anode but also as support to reversible cathode material. Operando measurements may provide several breakthroughs and allow the rational and real design of carbonaceous materials for high power anodes in all types of batteries.

Anomalous left coronary artery from pulmonary artery (ALCAPA) is an uncommon congenital heart defect. In most of the cases it presents in early infancy when the pulmonary artery pressure decreases and pulmonary vascular resistance falls. ECG and chest X-ray help in diagnosing this condition, however, transthoracic echocardiography confirms the diagnosis in most of the cases. 2D echo shows origin of left coronary artery from pulmonary artery and on colour Doppler retrograde flow is seen in left main, left anterior descending and left circumflex coronary arteries. Antegrade flow in the left coronary artery has been described in past when ALCAPA was associated with a shunt lesion like a ventricular septal defect (VSD) or a patent ductus arteriosus (PDA). We are reporting a case of ALCAPA with severe left ventricular (LV) dysfunction with normal flow pattern in left coronary artery with no associated cardiac anomaly and demonstration of retrograde flow on oxygen inhalation.

International audience; Platinum nanoparticles were deposited onto carbon aerogel with three different tin coatings. The coatings were synthesized at pH = 0.7 or 11.5 and with various masses of SnCl2.H2O precursor: 1, 2, and 10 g. The nanoparticles dispersion was found dependent on the morphological properties of the support, i.e., its specific surface, porosity, and coverage by tin oxide. The material electrochemical activity for the oxygen reduction reaction (ORR) and stability was investigated: two accelerated stress tests (ASTs), mimicking either a base-load cycle procedure (P1) or a start-stop procedure (P2), were performed at T = 80 °C. The sample coated at pH = 0.7 and the sample with the lowest loading, deposited at pH = 11.5, exhibited interesting performances, both in term of stability (under P1) and activity. On the contrary, samples with highly covering tin oxide coating displayed unsatisfactory initial performances, owing to the low electrical conductivity of their catalytic support. In any case, the aging under P2 leads in a dramatic decrease of the electrocatalyst activity. This either resulted from (i) the low degree of organization of the carbon aerogel, the latter being prone to harsh corrosion when non-covered by the tin oxide, or (ii) by the chemical changes undergone by the tin oxide during the AST, leading to the formation of an amorphous, low electrical conductivity support.

Composite waste, especially from wind turbine blades will increase foreseeably. The motivation of this paper is to develop new solutions to repurpose the global material stream coming from wind turbine blades at their end of use. Its suggested to use the composite structure for repurposing, differing from the available recycling methods that aim for a separation of the composite into fibre and matrix fractions. One key factor towards circularity in composite materials is converting significant amounts of composite material into multiple meaningful applications and products. Industry 4.0 can offer a systemic solution utilising robots and digital tools, such as a digital twin of a composite wind turbine blade. The digital handling of relevant material information can offer a new affordable material source to multiple industries, such as building industry or manufacturing businesses. Based on a digital platform the composite material can be made available for architects, designers and developers to repurpose composites into multiple new products.

Advanced composite drone manufacturing – additive manufacturing of continuous carbon fibre composites for function integrated lightweight drone parts Abstract Composite structures are state of the art technology for drones and drone parts. Lighter and stronger structures allow for longer flight time, higher payloads as well as improved flight performance. While composite materials promise huge lightweight potential, several composite manufacturing processes restrain this potential by restricting shape-ability and fibre misalignment during manufacturing. Additive manufacturing with continuous carbon fibres and thermoplastic matrix offers fibre alignment within the printed layers during production. The technology allows freedom of design to manufacture complex shaped parts. The carbon composite drone engine holder presented is designed for additive manufacturing using continuous carbon fibres with a thermoplastic matrix. Its design matches the aerodynamically shaped carbon monocoque of the drone and transmits loads from the engine into the carbon composite skin. Test flights of the drone showed the need for strong and tough materials especially in the front engine section. The required toughness could be achieved by using a thermoplastic matrix. The combination of design for manufacturing, fibre alignment and thermoplastic matrix leads to a light and tough solution. Another approach of ideal fibre alignment within composite manufacturing supports unidirectional alignment in symmetrical drone parts. So-called “spin-composite” manufacturing is a patent-pending manufacturing process for certain drone parts, like multi-copter drone fuselage. The presentation will introduce the technological principle and outline targeted composite structures.

International audience; In this study, Pt nanoparticles are synthesized on partially graphitic carbons, fluorinated or not. They are characterized for their physicochemical properties and oxygen reduction reaction activity, and tested in membrane electrode assemblies in unit proton exchange membrane fuel cell (PEMFC) cathodes; the results are compared with those of a benchmark TEC10EA40E® commercial electrocatalyst based on a low surface area highly-graphitized carbon. The home-made membrane electrode assemblies (MEAs) show performances approaching those of the commercial standard. The effect of the surfacic fluorination of the carbon is neither positive nor negative for the “load-cycling” protocol (benchmark MEAs optimized with the commercial electrocatalyst are more durable than non-optimized MEAs prepared with the two home-made electrocatalysts). In opposition, the fluorinated carbon-based electrocatalyst is the more durable in the AST mimicking repeated “start/stop” operation, at least in terms of electrochemical area loses. This demonstrates that carbon corrosion can be (at least partially) mitigated/slowed-down for a partially-fluorinated carbon versus the non-fluorinated substrate, leaving hope to enhance the durability of PEMFC cathodes for automotive applications. This study further demonstrates that the fate of (fluorinated) carbon-supported Pt nanoparticles may differ when the materials are operated in polymer versus liquid electrolyte.

International audience; Several carbon materials (one carbon nanotubes, two carbon blacks and one home-made carbon aerogel) were covered by thin tin dioxide (SnO2) nanoparticles coatings to improve their resistance against oxidation under the working conditions of Proton Exchange Membrane Fuel Cells. A pretreatment for the nanotubes in acidic media was also performed to improve their dispersion in the reactive medium. The coating was done by a chemical route. Samples were analysed by Scanning Electronic Microscopy (SEM), nitrogen sorption, X-ray diffraction (XRD), Raman spectroscopy, Fourier Transformed InfraRed (FTIR) and X-ray Photoelectron Spectroscopy (XPS). Their electrical conductivities were also measured. Using a reactive medium with a pH value exceeding the point of zero charge of the carbon materials is mandatory to favour electrostatic attractions, and to obtain covering and homogeneous coatings. In this condition, it is possible to reduce the quantity of precursor and to optimise the coating. The intrinsic properties of the carbon materials also influence the characteristics of the coatings. In fact, the least organised carbon materials with high specific surface area and porosity values exhibit homogeneous and covering coatings. On the contrary, organised carbon materials, with few oxygen-containing groups, lead to a smaller quantity and heterogeneous coatings (with some areas of carbon surface uncovered). The pretreatment performed on the nanotubes improves the characteristics of the coatings, even if using significant amounts of precursor remains necessary to obtain a covering and a homogeneous coating. The transformation mechanisms of the precursor into tin dioxide, depending on the pH, value are also discussed.

International audience; Fluorinated carbon nanotubes used as cathode material exhibit a capacity exceeding the theoretical value when used in primary lithium battery. The measured experimental capacity, the faradic yield and the energy density were increased, exceeding the expected theoretical values for sub-fluorinated few walled carbon nanotubes (FWCNTs).Although the molar carbon/fluorine ratio was only of 0.37 (i.e CF0.37), an experimental capacity of 900 mAh.g−1 was obtained which is higher than the theoretical value of 521 mAh.g−1. With the same material, an unprecedented energy density of 2565 Wh kg−1 was reached associated with a faradic yield of 172%. The materials were deeply characterized using TEM, Raman and solid state 13C and 19F NMR in order to explain the extra-capacity. Such high electrochemical values can be correlated to the reinforcement effect of the central tube(s), coupled with a low amount of structural defects.

International audience; Accordion-like graphites prepared by exfoliation of a low temperature graphite fluoride were fluorinated using F2 gas at various temperatures. The fluorinated exfoliated graphite exhibits unusual dual CF bonding, i.e. weakened covalent and covalent. This bonding allows the discharge potential at the beginning of the electrochemical processes to be increased. Moreover, the accordion-like texture avoids partial exfoliation and loss of the electrical contact for some parts of the electrode, and allows the growth of LiF particles in the opened macro-porosity.

Distributed generation (DG) is an essential attributor in smart grid to fulfill the uncontrollable increase in the demand for energy. Artificial intelligent optimization techniques are widely used within automation systems for guarantee the optimal operation and utilization of DG allocation on the day-ahead power scheduling. In this paper, the genetic algorithm technique used for obtaining the optimal utilization of the automated operation of distributed generation for power losses and total cost minimization as well as user comfort maximization considering all operating constraints technique. Distributed generation represented by fuel cells to supply part of the daily demand in the power system. The target is to apply decision-making strategy of smart operation for economical and reliable operation of power system. Concentrated fuel cell units considered representing the available DG at the load centers. The methodology applied to the 11-bus test system. The simulation results have demonstrated that the GA capability for full automation of DGs in a smart manner within the power system for economic and safe operation

Using galvanostatic discharges, the electrochemical properties of fluorinated carbon nanofibers (CNF) have been investigated. Several methods of fluorination are compared, (i) direct process using a flux of pure molecular fluorine F2 (dynamic process), (ii) controlled fluorination using atomic fluorine released continuously by the thermal decomposition of a solid fluorinating agent (TbF4), and (iii) static fluorination by the filling of a closed reactor with undiluted molecular fluorine as reactive gas. Electrochemical performances of the resulting materials are compared highlighting significant improvement using the static method. The discharge potential increases from 2.27 V (vs. Li+/Li°) for materials obtained by the direct route to a medium 2.40 V by the static route resulting from a two steps discharge mechanism. Owing to a complete characterization of each fluorinated materials by X-ray diffraction (XRD), solid state nuclear magnetic resonance (NMR) and transmission electron microscopy (TEM), the increased average potential of fluorinated sample through the static way has been explained by the peculiar distribution of fluorine and carbon sites in the nanomaterial. Then, in order to understand the two steps discharge mechanism of the latter material, its discharge mechanism through galvanostatic measurements at different depths of discharge has been investigated in different electrolytes. The discharged materials have been studied owing to 19F MAS NMR, XRD and scanning electron microscopy characterizations. The texture and cristallinity of lithium fluoride particles are key parameters acting on the ionic diffusion of Li+ and F− ions and as a consequence on the electrochemical performances. Its high solubility in EC/PC/3DMC solvent mixture prevents from overvoltage phenomenon occurring during the discharge of fluorinated carbon nanofibers in primary lithium battery.

Graphite fluorides with different structural types (CyF)(n) (y = 2.5, 2, and 1) and room temperature graphite fluorides were studied by solid state,NMR and NEXAFS. Data extracted from those two techniques are complementary, providing information about the C-F bonding and the hybridization character of the carbon atom valence states. The comparison of data obtained by different methods such as NMR, Raman, and X-ray absorption leads to similar conclusions regarding the chemical bonding in fluorographites. Several major configurations of fluorinated graphites are discussed, that is, planar sheets with mainly sp(2) hybridization in room temperature graphite fluorides and corrugated sheets with sp(3) hybridization in covalent high temperature graphite fluoride. Different references such as highly oriented pyrolytic graphite (HOPG), graphitized carbon nanodiscs (graph-CNDs) and nanodiamonds (NDs) have also been investigated for comparison.

Proton exchange membrane fuel cells (PEMFC) are energy converters that can power nomad, automotive or stationary systems without emission of pollutants. This technology is already used for niche markets, but some challenges must be overcome to enable large-scale deployment. In particular, the electrochemical corrosion of the carbon support at the cathode remains a major concern especially under start-stop conditions. This corrosion causes massive detachment of the supported Pt-based nanocrystallites, negatively affects water management and ultimately results into a collapse of the electrode structure. In this study, we bridged the textural and the structural properties of a set of carbons supports to their resistance to corrosion. The stability of carbon nanotubes (CNT, graphitized but with a low specific surface area), carbon blacks (featuring either large specific surface area but poorly-structured, CBe, or low specific surface area and high degree of graphitization, CBs) and carbon aerogel (controlled texture but low degree of organization, CA) was investigated via accelerated stress tests derived from the FCCJ organization. A trade-off was found in terms of properties: graphitic carbons are more resistant to oxidation, whereas carbon supports featuring high specific surface areas are more favorable to the dispersion of a large amount of catalyst nanoparticles per unit volume. Controlled fluorination of these model carbon supports was performed so as to improve their resistance to electrochemical corrosion [1]. The fluorination was carried out by an easily scalable solid gas process using pure molecular fluorine [2]. The parameters were set in order to limit the fluorination below 0.2 fluorine atom per carbon atom and to avoid any carbon decomposition into gaseous fluorinated compounds such as CF4 and C2F6 [3]. Platinum nanoparticles were also deposited (40 wt.%) by a colloid (polyol) method on the bare and fluorinated carbons. The samples were physically and chemically characterized by XRD, TEM (Figure 1), nitrogen sorption, FTIR and TGA. The catalytic activity of these electrocatalysts towards the oxygen reduction reaction was determined by linear sweep voltammetry (rotating disk electrode technique). Accelerated stress tests, load cycle (0.6-1.0 V) and start-up/shutdown (1.0-1.5 V) protocols, conducted at T= 80°C in a four-electrode cell [4], were performed to investigate the robustness of the bare and fluorinated Pt electrocatalysts. The results and the impact of the fluorination are discussed and compared to those of a commercial 40 wt.% electrocatalyst. [1] S. Berthon-Fabry et al. First insight into fluorinated Pt/carbon aerogels as more corrosion-resistant electrocatalysts for Proton Exchange Membrane Fuel Cell cathodes, Electrocatalysis, 6, 6 (2015) 521-533 [2] N. Batisse, P. Bonnet, M. Dubois, K. Guérin, Fluorination of 0D, 1D and 2D nanocarbons” In: Carbon Nanomaterials Sourcebook (Eds. Taylor & Francis Publisher), 2016[3] Y Ahmad et al., The synthesis of multilayer graphene materials by the fluorination of carbon nanodiscs/nanocones. Carbon, 50, 10 (2012) 3897-3908 [4] L. Dubau, F. Maillard, “Unveiling the crucial role of temperature on the stability of oxygen reduction reaction electrocatalysts”, Electrochem. Commun., 63 (2016) 65-69. This work is funded by the French National Research Agency programme, (ANR-14-CE05-0047 project CORECAT and is supported by Capenergies and Tenerrdis Figure 1: TEM images of bare CBe (left), Pt/CBe (middle) and Pt/F-CB (right) samples Figure 1

International audience; Proton exchange membrane fuel cells (PEMFC) are devices that convert chemical energy into electricity in a clean and efficient manner. They can be used in automotive, nomad, or stationary applications without emission of pollutants (neither gas nor particles).After several decades of scientific and technological improvements, the PEMFC technology is now mature and starts to be deployed on the field, but some drawbacks must be overcome; in particular, their durability in operation must be increased. The durability strongly depends on the technical choice of the PEMFC manufacturer (bipolar plates, membrane, and quality of the hydrogen) but also especially the resistance to degradation of the carbon support and the catalyst and the water management. This study evaluates the fluorination of a carbon aerogel and gives first insights into its durability when used as platinum electrocata-lyst substrate for proton exchange membrane fuel cell (PEMFC) cathodes. Fluorine has been introduced before or after platinum deposition (Figure 1). The different electrocatalysts are physico-chemically and electrochemically char-acterized, and the results discussed by compari-son with commercial Pt/XC72 from E-Tek. The results demonstrate that the level of fluori-nation of the carbon aerogel can be controlled. The fluorination modifies the texture of the carbons by increasing the pore size and decreasing the specific surface area, but the textures remain appropriate for PEMFC applications. Two fluorination sites are observed, leading to both high covalent C-F bonds and weakened ones, the quantity of which depends on whether the treatment is done before or after platinum deposition. The order of the different treatments is very important. Indeed, the presence of platinum contributes to the fluorination mechanism, but leads to amorphous platinum, which is demonstrated rather inactive towards the oxygen reduction reaction. On the contrary, a better durability was demonstrated for the fluorinated and then platinized catalyst compared both to the same but not fluorinated catalyst and to the reference commercial material (based on the loss of the electrochemical real surface area after accele-rated stress tests).

فتحت الفيوم صلحا عام 21هـ/ 642م، على يد خارجة بن حذافة السهمي، بإيعاز من عمرو بن العاص (ت43هـ/663م) ، ثم شرع من بعد ذلک والي مصر قرة بن شريک العبسي (ت96هـ/715هـ)في إقامة مسجدها، وعلى الرغم من عدم الوقوف على تاريخ محدد لإنشاء هذا المسجد، فمن المؤکد أنه أنشئ فيما بين عامي 90هـ/907م و 96هـ/908م، وهي الفترة التي تولي فيها " قره " ولاية مصر. ولما کان من المعلوم أن الحرکة الفکرية والعلمية في الأمصار والحواضر الإسلامية ارتبطت في الأصل بنشأة المساجد، فارتباط الفيوم بالحرکة العلمية والفکرية في العصر الإسلامي بدأت منذ ذاک الحين، والظاهر أن ذلک مثل حافزا لدى أبناء الفيوم لطلب العلوم والمعارف الإسلامية الجديدة. وإذا کان الجانب الاقتصادي هو الأبرز في المصادر ذات الصلة بتاريخ الفيوم، فقد دلت الإشارات التاريخية على أن العديد من العلماء الذين انتسبوا للفيوم، أسهموا في شتى صنوف العلوم لاسيما العلوم الدينية على مدار قرون عديدة. وعلى الرغم من أن النصوص المتعلقة بهذا الموضوع اتسمت بالندرة، فضلا عن کونها طرحت مبثوثة في بطون کتب التراجم والطبقات منثورة بين ثنايا الأخبار، فإنها صالحة للوقوف على تصور لا بأس به عن هذه الصفحة المطوية من تاريخ الفيوم، ولما تبين لکاتب هذه السطور أن أحدا لم يضطلع ببحث هذا الموضوع، نهض ذلک باعثا لديه لاستقصائه والکشف عن أبعاده، من خلال هذه الدراسة الموسومة بـ" علماء الفيوم ودورهم في الحياة العلمية من العصر العباسي الأول حتى نهاية العصر المملوکي (132-923هـ/750-1517م ) ". هذا ويقتضي المقام قبل ولوج موضوع الدراسة، التعريف بالمنهج المعتمد في الکشف عن علماء الفيوم في المصادر التاريخية ومظانها، فمن المعلوم أن انتساب الأشخاص قبل الإسلام کان منصرفا فقط للقبيلة، أما بعد الإسلام، فقد انتشر العرب خارج الجزيرة العربية إثر حرکة الفتوح، فسکنوا المدن والأمصار، وخالطوا أهلها، واشتغلوا فيها بالعلوم والآداب والفنون والحرف، وبمرور الوقت أفضي هذا الأمر إلى تعذر نسبة الفرد إلى القبيلة أو الجنس، خاصة بعد أن دخلت إلى الإسلام عناصر أخري غير عربية.

Multilayer carbonaceous nanomaterial has been synthesized using a two-step process: carbon nanodiscs/nanocones were fluorinated using either the direct reaction with pure F2 gas or the thermal decomposition of solid fluorinating agent (TbF4). Then the fluorinated parts were removed by treatment at 600 °C in air. When the fluorine atoms are homogenously dispersed, using fluorination by TbF4, thinning due to thermal defluorination results in multilayer materials with 7–10 nm of thickness and 400–500 nm of width. Such resulting materials and the fluorinated precursors have been characterized by solid state NMR, TGA, XRD, SEM, TEM, AFM and Raman spectroscopy.

When the carbon lattice of the starting material exhibits a curvature as in the case of fullerenes and derivatives, the C–F bonding in the compounds resulting from the fluorination using molecular fluorine is strongly affected and the covalence is significantly weakened. 19F solid state NMR underlines that the higher the curvature the lower the C–F bonding covalence is. The electrochemical discharge potentials of these materials used as electrode in primary lithium batteries can be then tuned according to the curvature, i.e. the diameter of the outer tubes. The potential decreases from 2.9 to 2.3 V versus Li+/Li° according to the following classification: SWCNTs, MWCNTs and carbon nanofibres, which can be described as MWCNTs with large diameter due to the high number of walls. The case of highly fluorinated fullerenes is different because several types of bonding coexist and are progressively broken during the electrochemical process at potentials ranged in between 2.0 and 3.6 V. The behaviour of fluorinated nanocarbons is also compared to conventional graphite fluorides.

The clinical detail, echocardiographic features, angiographic evaluation, and surgical repair of double-outlet left atrium (LA) in a 2-year-old boy are discussed. In a solitus position and normally connected systemic and pulmonary venous drainage setting, the only outlet of the right atrium was a secundum atrial septal defect. The LA thus received the entire venous return and then drained into both ventricles through a common atrioventricular valve.

International audience; Li–CFx battery using a specific fluorinated nanocarbon as cathode material exhibits a capacity exceeding the expected theoretical value when used as an electrode material in primary lithium battery. Carbon nanodiscs were partially fluorinated by atomic fluorine released by thermal decomposition of TbF4, and the capacity of this material was up to 1180 mAh g−1, whereas a theoretical value of 847 mAh g−1 for the CF0.95 sample was calculated. The obtained value is also higher than the maximum one of 865 mAh g−1 expected for CF1 carbon fluorides. The discharge mechanism was investigated using mainly SEM and solid state NMR in order to understand this “extra-capacity”. Both the un-fluorinated carbon and the LiF covering, which is formed outside the carbon lattice during the discharge mechanism, play a key role for the achievement of the extra-capacity by the consumption of Li+ to form Li2F+ species stabilized by the carbon host structure formed after the electrochemical de-fluorination.

International audience; Accordion-like graphites prepared by exfoliation of a low temperature graphite fluoride were fluorinated using F2 gas in order to be considered as solid lubricants and electrode materials in primary lithium battery. The present work focuses on the fluorination mechanism of such material. In accordance with their high specific surface area, the fluorination is efficient even at room temperature. Whatever the treatment conditions, the accordion-like texture is maintained. The higher the reaction temperature, the higher the atomic ratio F/C. The fluorinated exfoliated graphite exhibit unusual dual Csingle bondF bonding. Both weakened covalent and covalent Csingle bondF bonds coexist. Moreover, the Csingle bondF bond strength is enhanced as a function of the fluorination temperature.

International audience; The thermal exfoliation of graphite fluoride was investigated using two starting materials: fluorinated HOPG and powdered room temperature graphite fluoride (RTGF) post-treated in pure F2 gas in order to adjust the relative contents of intercalated species, the carbon hybridization and the C–F bonding. Firstly, the thermal exfoliation of HOPG sample (of composition CF0.57) at the nanoscale is highlighted using scanning tunneling microscopy (STM). Such process involves a defluorination, which is accelerated by disruption of the graphene sheets. Similar breaking occurs during the exfoliation of post-treated RTGF and evolves CF4 and C2F6 gases. Moreover, the exfoliation using a thermal shock is assisted by the fast deintercalation of the catalyst species in the region where the covalence of the C–F bonds is weakened. In such way, exfoliation occurs with the quasi-total defluorination.

Two synthesis ways were applied to fluorination of a novel nano-sized graphitized carbon black: (i) direct fluorination (under a flux of pure molecular fluorine) and (ii) controlled fluorination by TbF4 thermal decomposition. The thermal, electrochemical and tribologic properties of the various fluorinated nanocarbons obtained have been investigated. Fluorinated compounds produced by means of controlled fluorination present higher thermal stability and better tribologic properties than those obtained using direct fluorination. On the other hand, the study of the electrochemical performances as electrode material in primary lithium battery underlines that the direct fluorination is more efficient than the controlled way taking into account the energy and power densities. Each fluorination way leads to specific mechanisms of covalent grafting of fluorine atoms onto nanocarbons. These mechanisms have been studied by deep physical–chemical characterizations by X-ray diffraction (XRD), transmission electronic microscopy (TEM) and solid state nuclear magnetic resonance (NMR) with 13C and 19F nuclei in order to determine the C F bond nature, the structure and textural properties of the fluorocarbon compounds.

International audience; This study evaluates the fluorination of a carbon aerogel and its effects on the durability of the resulting electrocatalyst for Proton Exchange Membrane Fuel Cell (PEMFC). Fluorine has been introduced before or after platinum deposition. The different electrocatalysts are physico-chemically and electrochemically characterized, and the results discussed by comparison with commercial Pt/XC72 from E-Tek. The results demonstrate that the level of fluorination of the carbon aerogel can be controlled. The fluorination modifies the texture of the carbons by increasing the pore size and decreasing the specific surface area, but the textures remain appropriate for PEMFC applications. Two fluorination sites are observed, leading to both high covalent C-F bond and weakened ones, the quantity of which depends on whether the treatment is done before or after platinum deposition. The order of the different treatments is very important. The presence of platinum contributes to the fluorination mechanism, but leads to amorphous platinum rather inactive towards the Oxygen Reduction Reaction. Finally, a better durability was demonstrated for the fluorinated then platinized catalyst compared both to the same but not fluorinated catalyst and to the reference commercial material (based on the loss of the electrochemical real surface area after accelerated stress tests).

The Li/CFx primary battery is the first lithium battery developed since the 1970th, and it possesses the highest energy-density among all primary lithium batteries (theoretically 2180 W h kg-1).When fluorinated carbons (denoted CFx) are used as electrode material in primary lithium battery, the C-F bonds are broken during the electrochemical discharge and carbon and LiF particles are formed. Then, the higher the fluorine content, the higher the theoretical capacity, the maximal value being 865 mAh/g for a CF1 composition. Although this limitation, we found higher capacities (Cexp) than the theoretical ones (Ctheo) for several optimized fluorinated nanocarbons. The faradic yield, defined as 100xCexp/Ctheo, was then higher than 100% and reached even 170%. This means that a second electrochemical process takes place after the defluorination. In order to understand such additional mechanism, a set of carbonaceous nanomaterials, namely carbon nanodiscs, graphitized carbon blacks, double- and multi-walled were fluorinated using either pure F2 gas or a solid fluorinating agent (TbF4) and their electrochemical performances were investigated. After a deep characterization of the material (SEM, TEM, XRD, 19F solid state NMR, EPR), the discharge mechanisms were investigated using the same complementary techniques and compared to conventional graphite fluorides. This systematic study of about ten different CFx underlined that the key point for the extra-capacities lies in both the maintaining of some unfluorinated parts and the ability of the fluorinated carbon to reform its raw structure after electrochemical defluorination are necessary for extra-capacity. LiF particles, which are formed during this process, are then located outside the new carbonaceous matrix and may participate to the second mechanism, similar to the intercalation into the freshly formed carbon matrix. These two processes, electrochemical defluorination and intercalation into the defluorinated carbon are well exemplified by the case of carbon nanodiscs. This sample was fluorinated with TbF4 in order to homogenously locate the fluorine atoms in the whole volume of the discs, except in the central discs, less or not fluorinated. The deep characterization of the fluorinated discs allows this conclusion to be proposed in accordance with the properties of the starting materials. After the defluorination, a shell of agglomerated LiF particles covered the discs. Any exfoliation of the discs has been observed after the defluoration contrary to the studied conventional graphite fluoride. The process similar to an intercalation into the reformed discs may take place thanks to the maintaining of the discotic geometry. The extra-capacity comes from this additional process, which occurs through the LiF shell. In other words, the less or not fluorinated central discs act as a reinforcement that allows the rebuilding of the carbon matrix. Both the unfluorinated carbon and the LiF covering, which is formed outside the carbon lattice during the discharge mechanism, play a key role for the achievement of the extracapacity by the consumption of Li+ to form Li2F+ species stabilized by the carbon host structure formed after the electrochemical defluorination. The necessity of a reinforcement was then confirmed for the cases of fluorinated double and low diameter multi-walled carbon nanotubes, for which the fluorination with F2 gas has been conducted in order to avoid the fluorination of the inner tube, which allows the reinforcement and the carbon rebuilding. The higher faradic yield (170%) was obtained for those samples.

Eosinophilia is a very unusual and rare cause of thrombosis of prosthetic mitral valve. We report a 10-year-old male child of recurrent stuck prosthetic mitral valve. The child underwent mitral valve replacement for severe mitral regurgitation secondary to Rheumatic heart disease. He had recurrent prosthetic mitral valve thrombosis, despite desired INR levels. There was associated eosinophilia. The child was treated on the lines of tropical eosinophilia with oral prednisolone and diethylcarbamazine, the eosinophil count dropped significantly with no subsequent episode of stuck mitral valve. We discuss the management of recurrent stuck mitral valve and also eosinophilia as a causative factor for the same.

2 Favre, Nathalie Ahmad, Yasser Pierre, Alain C.; As part of an effort to develop biomaterials for the capture of CO2 catalyzed by a carbonic anhydrase enzyme, the effects of an aqueous CO2 saturated solution and a carbonic anhydrase on the gelation and texture of SiO2 gels derived from tetramethoxysilane (TMOS), were studied. Both aqueous CO2 and the enzyme were found to accelerate the gelation of silica, with a stronger effect when both the enzyme and CO2 saturated aqueous water, were used. According to the gel texture data, aqueous CO2 acted as an acid type catalyst, while the carbonic anhydrase acted as a weak base type catalyst. Moreover, a gel with a more granular visual aspect was obtained when both the enzyme and CO2 saturated water were used. The latter characteristic was consistent with a double action of the enzyme, first as a gelation catalyst on the silica precursor, secondly as a reverse protonation catalyst which accelerated the back nucleation of CO2 gas bubbles from aqueous HCO3 (-) anions.

Increased understanding of the mechanical and physical properties of the lungs and gas flow has allowed considerable advances in the field of mechanical ventilation and lung protection. Maintaining laminar flow, ‘the physiological flow’, and preventing turbulent flow during mechanical ventilation prevent atelectasis and help keep the lung open. This protects the lung from ventilator-induced lung injury (VILI). Analysis of the pressure–volume ( P/V ) curve of the respiratory system is the basis for maintaining lung protection. Lung volumes affect the dynamics of the lung and usually have a significant effect on the flow, airway resistance, lung compliance, ventilation–perfusion ratio and recruitment. Functional residual capacity (FRC) has a significant role in maintaining the structure and function of the lung, and the relationship between the FRC and closing volume (CV) is more important than considering the FRC and CV alone. Positive end-expiratory pressure (PEEP), by preventing and/or recruiting atelectatic lung regions, can maintain the lung structure and protects against VILI. The optimal PEEP, still controversial, can be determined using the following methods: (1) a decremental PEEP trial after recruitment manoeuvres with P aO2 and lung compliance guidance; (2) (quasi) static approaches or dynamic approaches based on the P/V curve; (3) based on the F iO2/PEEP table with oxygenation guidance; (4) PEEP guided by oesophageal pressure; (5) based on a computerized tomography scan or chest radiograph; and (6) using electrical impedance tomography. Recruitment manoeuvres can help to recruit atelectatic lung regions and can be accomplished by raising the transpulmonary pressure periodically and briefly to a higher level than that achieved during tidal ventilation. Clinical and experimental studies has been conducted to identify the durability of the beneficial effects of recruitment manoeuvres, when and how to perform them, early or late in the course of acute respiratory distress syndrome and with high or low PEEP, and which categories of patients will benefit from them.