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The synthesis of β-type phase NbxTi (x= 50 at%) / SWCNTs (Single Walled Carbon Nanotubes) intermetallic matrix nanocomposite by mechanical alloying to ensure the effective distribution of (SWCNTs) within the matrix. It has been stated by several researchers that during ball-milling of NbxTi (x =50 at%) powder mixtures, Nb-Ti intermetallic compound formation occurs either gradually along milling time of mechanical allowing (MA), or suddenly through amechanically self-propagating reaction (MSPR), which occurs after a ignition time of MA. For this purpose, 0.4and 0.8 at% of SWNTs was added to the powder mixture after the completion of reactionbetween Nb and Ti. The obtained powders Nb50Ti intermetallic compound mixed with SWCNTs powder and then was also ball-milled. Bulk samples were compacted and then sintered by (FAST-SPS-FCT) method (Field Assisted Sintering Technics-Sparck Plasma Sintering- Furnace, Advanced Ceramics for High-Temperature) at the temperature range (1273-1473 °K) with some time that retained the integrity of SWNTs in the intermetallic matrix.Structural and mechanical and vibronic changes of the nanocomposites were investigated by X-ray diffractometery (XRD). Field emission scanning electron microscopy (FESEM) micrographs showed that the offered MA approach caused the SWNTs to be uniformly embedded in the in situ synthesized NbTi intermetallic matrix. Meanwhile better distribution of SWCNTs resulted in higher density of FAST-SPS-FCT bulk nanocomposite as well higher hardness up to 2.75GPa compared to 2.4 of Nb50Ti intermetallic alloy obtained after MA time. The total porosity, compressive strength, and compressive elastic modulus of the FAST-SPS-FCT manufactured material were determined as 7%, 600 MPa, and 120 MPa, respectively. The alloy’s and its intermetallic nanocomposite have Young’s elastic modulus is comparable to that of healthy cancellous bone which makes it applicable in the biomedical field. The in vitro biocomptability will be performed in the near future. The comparable results for the FAST-SPS-FCT nanocomposites were 3%, 650 MPa, and 130 MPa. The alloy’s elastic modulus is comparable to that of healthy cancellous bone. This difference in mechanical properties results from different porosity and phase composition of the bot β-phase NbxTi (x= 50 at%) and NbxTi (x= 50 at%)/SWCNTs intermetallic matrix nanocomposite. More other nanotechnologies applications of the nanocomposite will be focused in the study of the superconducting type I for the ITER Poloidal Field Coils by measuring of Jc (T, B) characteristics.

High recurrent fluorescence rates of tetracene cations, C18H12, measured with two electrostatic ion rings, DESIREE and Mini-Ring, lead to much more effective radiative cooling than previously investigated PAH cations.

The purpose of this work is to decrease or eliminate porosities of ETER-VC (Electrothermal Explosion Reaction-Volume Combustion) products with the sintering additives. The Ti–C system has been synthesized for its advantages for refractory, abrasive and structural applications. We attempted to densify TiC by using iron addition; this metal is introduced through a reaction 3TiO3+Al+C. This mixture reacted exothermically (ϪH298 = -1072.7 kJ) and this heat is released according to the Fe addition using the following reaction: 3TiO3+4Al+3C+xFe→3TiC+2Al2O3+xFe. .X-ray diffraction analysis indicated that intermetallic Fe3Al, TiC and Al2O3 are the main phases formed in the reinforced high performance ceramic-matrix composites. The increasing of x wt. % iron decreased the lattice parameter of TiC. Field emission scanning electron microscopy examinations showed that the addition of Fe decreased TiC particle size and changed their growth controlling mechanism. Also, Raman spectroscopy analysis demonstrate that at higher Fe contents, oxygen dissolved in the TiC crystal structure leading to the formation of titanium oxy-carbide with lower lattice parameter and residual un-reacted carbon in the products. The adiabatic temperatures for the reactions containing x wt. % Fe estimated using the thermodynamic data according to Merzhanov criteria. Thus, doping method is finally used to fabricate materials by ETER-VC combustion mode for industrial applications.

Nanocomposites are worn resistant materials used in cutting tool applications. The materials are composed of ultrafine powder hard phase grains surrounded by a tough binder phase carbon nanotubes (Mo2C)1-x–(TiC)x (2≤x≤4)//1Wt% SWCNTs. Composite bicarbide Mo2C-TiC was rapidly synthesised and simultaneously consolidated by field activated sintering technique (spark plasma sintering) at which the extensive volume expansion occurred as a function of the volumic fraction from 20 to 40 vol.% of TiC powders and 1 Wt.% of SWCNTs was reinforcement of the NCMC’s. The sintered powder mixture was examined by XRD patterns, the morphology of the obtained phase was observed by SEM and the phase compositions in different regions were analyzed by EDX. The composites were processed using Field Activated Sintering Technique, spark plasma sintering (SPS) at temperatures in the range of 1700-1800°C with addicting of SWCNTs. The effects of SWCNTs addition on phases morphology, microstructure hardness and fracture toughness of the nanocomposite were investigated. The best product contained 1.0 Wt% SWCNTs from (Mo2C)1-x–(TiC)x , x= 0.2 which was sintered at 1700°C, 70 MPa for 10 min, M0.8T0.2/ 1 Wt% SWCNTs exhibit a better density, highest hardness and good ductility. Relative densification was achieved 99.5 % from the theoretical and good mechanical properties like hardness and fracture toughness (KIC=5.6 Mpa m1/2) are improved. The results were confirmed using Raman scattering resonant spectroscopy.

Cubic boron nitrid (cBN) bonded TiC and alloyed with single walled carbon nanotubes (SWCNTs or NC) ceramics matrix nanocomposites (CMNCs) tools were manufacturated by a field actived sparck plasma sintering processus (FASPS). The effects of cBN-TiC ratio, carbon nanotubes and optimisation of the sintering process on the microstructure, densification in addition mechanical and vibronic properties of NC-cBN-TiC nanocomposites were studied. The results showed that for the nanocomposite cBN-TiC vol. ratio of 8:2 with 0.1 wt% NC, it was found that microhardness incresses significantly with addition of carbon nanotubes exhibited the highest microhardness and fracture toughness. After sintering of the samples at 1800 °C, 10 mn, 75 MPa of cBN–TiC1-x, x=0.8 with and without addition of 0.1 wt% NC were characterized using field emission scanning electron microscopy (FESEM) and X-ray diffraction. The samples exhibited a dense polycrystalline structure. From the resonant Raman scattering we can locate the vibration frequency of the transformation cBN to hexagonal boron nitrid (hBN) and formation of secondary hard phase TiB2to consolid the (CMNCs) tools. The final product is hBN-TiC-TiB2-NC.The best product contained cBNx-TiC1-x (x=0.8)-0.1 wt % NC which was sintered at 1800 °C, 75 MPa for 10 mn. The Vickers hardness of cBN-TiC1-x (x=0.8) incresses with NC incorporation in the matrix The indentation fracture toughness was calculated to be 12.30 MPa m1/2 for cBNx-TiC1-x (x=0.8 -0.1 wt % NC ceramics matrix nanocomposite (CMNCs) tools with excellent wear resistant will be confirmed. The wear of cBN-TiC of the composites tools have shown that this is predominantly a chemical process involving the interaction of the tool with its environment and is restricted by the formation of protective layers on the exposed faces of the tool by the addition of carbon nanotubes (NC). The wear features of tools used in fine cutting tests under identical conditions will be compared and the results will be interpreted in terms of the existing models for the wear of cBN -based nanomaterials by the effects of the additives in the modified tools

The purpose of this work is to decrease or eliminate porosities in electro-thermal explosion (ETE-VC) products with sintering additives. The Ti–C system has been synthesized for its advantages for refractory, abrasive and structural applications. We attempted to density TiC by using iron addition; this metal is introduced through a secondary reaction 3TiO3+Al. This mixture reacts exothermically ϪH298 = -1072.7 kJ and the heat is released according to by Fe addition 3TiO3+4Al+3C+xFe→3TiC+2Al2O3+xFe. .X-ray diffraction analysis indicated that intermetallic Fe3Al, TiC and Al2O3 are the main phases formed in the reinforced high-performance ceramic-matrix composites and the additions of Fe decreased the lattice parameter of TiC. Field emission scanning electron microscopy examinations showed that the addition of Fe decreased TiC particle size and changed their growth controlling mechanism. Also, Raman spectroscopy analysis showed that at higher Fe contents, oxygen dissolved in the TiC crystal structure leading to the formation of titanium oxy-carbide with lower lattice parameter and residual un-reacted carbon in the products. The adiabatic temperatures for the reactions containing % Fe estimated using the thermodynamic data. Thus, doping method is finally used to fabricate materials by ETE-VC method (volume combustion method) for industrial applications.

International audience; In this paper, we present an experimental and theoretical study of the photo-dissociation of free-flying dimer radical cations of pyrene (C16H10)2+. Experimentally, the dimers were produced in the plasma of an electron cyclotron resonance ion source and stored in an electrostatic ion storage ring, the Mini-Ring for times up to 10 ms and the photo-dissociation spectrum was recorded in the 400 to 2000 nm range. Two broad absorption bands were observed at 550 (2.25 eV) and 1560 nm (0.79 eV), respectively. Theoretical simulations of the absorption spectrum as a function of the temperature were performed using the Density Functional based Tight Binding approach within the Extended Configuration Interaction scheme (DFTB-EXCI) to determine the electronic structure. The simulation involved all excited electronic states correlated asymptotically with the five lowest excited states D1–D5 of the monomer cation and a Monte Carlo exploration of the electronic ground state potential energy surface. The simulations exhibit three major bands at 1.0, 2.1 and 2.8 eV respectively. They allow assigning the experimental band at 1560 nm to absorption by the charge resonance (CR) excited state correlated with the ground state of the monomer D0. The band at 550 nm is tentatively attributed to dimer states correlated with excited states D2–D4, in the monomer cation. Simulations also show that the CR band broadens and shifts towards longer wavelength with increasing temperature. It results from the dependence on the geometry of the energy gap between the ground state and the lowest excited state. The comparison of the experimental spectrum with theoretical spectra at various temperatures allows us to estimate the temperature of the stored (C16H10)2+ in the 300–400 K range, which is also in line with the expected temperatures of the ions deduced from the analysis of the natural decay curve.

Nowadays, micro-scale piezoelectric devices with high sensitivity are much in demand for transducer technologies. This work suggests a low cost technology consisting of a screen-printing process associated with a sacrificial layer for preparation of microceramic-disks. These printed microdisks are based on a PZT layer sandwiched between two printed electrodes. The printed microdisks can be released from substrates by co-firing, leading to a complete decomposition of the sacrificial layer. The effect of different electrode materials (Au and Ag/Pd) on the releasing behavior is described. Uniform releasing is obtained by Ag/Pd electrodes whereas Au electrodes perform partial sticking on the substrates. Furthermore, the printed microdisks made of different PZT particle sizes are compared in terms of microstructure, electromechanical, and dielectric properties. The dense microdisks obtained from nanometric PZT particles and Ag/Pd electrodes generate high values of effective electromechanical coupling coefficient (45%) and relative permittivity (1200). Therefore, these printed microdisks are considered to be potential candidates for different sensing and actuating applications.

Synopsis Anthracene cations (C14H10 +) have been stored in the cryogenic (13 K) electrostatic storage ring DESIREE in Stockholm to study their radiative cooling dynamics on a long time scale up to 2 s. By monitoring the laser-induced delayed dissociation curves during the storage, the evolution of the dissociation rate was obtained. Its decrease as a function of time is closely related to the time evolution of the internal energy distribution of the stored anthracene cations and consequently to the energy loss due to radiative cooling, including both Poincaré and infrared fluorescences.

Cubic boron nitrid (cBN) bonded TiC and alloyed with single walled carbon nanotubes (SWCNTs or NC) ceramics matrix nanocomposites (CMNC's) tools were fabricated by a field active sparck plasma sintering process (FASPS). The effects of cBN-TiC ratio, carbon nanotubes and optimization of the sintering process on the microstructure, densification in addition mechanical and vibronic properties of NC-cBN-TiC nanocomposites were studied. The results showed that the nanocomposite cBN-TiC vol. ratio of 8:2 with 0.1 wt% NC. It was found that microhardness increases significantly with addition of NC exhibited the highest microhardness and fracture toughness. After sinters of the samples at 1800℃, 10 mn, 75 MPa of cBN–TiC1-x with x=0.8 with and without addition of 0.1 wt% NC were characterized using field emission scanning electron microscopy (FESEM) and X-ray diffraction. The samples exhibited a dense polycrystalline structure, from the resonant Raman scattering we can locate the vibration frequency of the transformation cBN to hexagonal boron nitrid (hBN) and formation of secondary hard phase TiB2 to consoled the (CMNC's) tools. The final product is hBN-TiC-TiB2-NC.The best product contained cBNx-TiC1-x (x=0.8)-0.1 wt% NC which was sintered at 1800℃, 75 MPa for 10 mn. The Vickers hardness of cBN-TiC1-x (x=0.8) increases with NC incorporation in the matrix The indentation fracture toughness was calculated to be 12.30 MPa m1/2 for cBNx-TiC1-x (x=0.8)-0.1 wt% NC ceramics matrix nanocomposite (CMNC's) tools with excellent wear resistant will be confirmed. The wear of cBN-TiC of the composites tools have shown that this is predominantly a chemical process involving the interaction of the tool with its environment and is restricted by the formation of protective layers on the exposed faces of the tool by the addition of NC. The wear features of tools used in fine cutting tests under identical conditions will be compared and the results will be interpreted in terms of the existing models for the wear of cBN-based nanomaterials by the effects of the additives in the modified tools.

Nanocomposites are wear resistant materials used in cutting toAbstract Nanocomposites are wear resistant materials used in cutting tool applications. The materials are composed of ultrafine powder hard phase grains surrounded by a tough binder phase carbon nanotubes (Mo2C)1-x(TiC)x (2≤x≤4)//1Wt% SWCNTs. Composite bicarbide Mo2C-TiC was rapidly synthesised and simultaneously consolidated by Field activated sintering technique (spark plasma sintering) at which the extensive volume expansion occurred as a function of the volumic fraction from 20 to 40 vol.% of TiC powders and 1 Wt.% of SWCNTs as reinforcement of the CMNC’s. The sintered powder mixture was examined by XRD patterns, the morphology of the obtained phase was observed by SEM and the phase compositions in different regions were analyzed by EDX. The composites were processed using Field Activated Sintering Technique, spark plasma sintering (SPS) at temperatures in the range of 1700-1800&#8451 with addicting of SWCNTs. The effects of SWCNTs addition on phases morphology, microstructure hardness and fracture toughness of the nanocomposite were investigated. The best product contained 1.0 Wt.% SWCNTs from (Mo2

Total hip arthroplasty (THA) and Total knee arthroplasty (TKA) (Figure 1) has been a successful, increasing practice for caring for hip arthritis in the aging and active population by novel biomaterials

Total Hip Arthroplasty (THA) is used to replace a damaged hip joint. Bone is a living tissue which remodel itself depending on its solicitations.

International audience; This paper is focusing basically on the ceramic technology, of which several methods for the synthesis of MgAl 2 O 4 have been investigated. The synthesis conditions regarding the powders cleanliness, microstructure, and sintering parameters of MgAl 2 O 4 were studied. MgAl 2 O 4 powder was synthesized via conventional solid-state route using different milling process vertical attrition milling, WAB as a high-energy horizontal attrition milling, and Pulverisette as a planetary ball miller, and via solution combustion route using Urea, Glycine, and a mixture of Urea/Glycine. Urea and Glycine was used as fuel. The white powders were obtained for all solid-state routes and for Urea-combustion technique. The black and gray powders were obtained in the case of combustion technique, respectively, using a fuel of Glycine and Glycine/Urea mixture. The obtained powders and pellets were characterized by XRD, SEM, and Dilatometry. The results show that, among all the solid-state route processes, wet attrition milling gives the better and clean spinel phase. The WAB milling and Pulverisette miller introduce a contamination by some yttria-stabilized zirconia balls in the corresponding powder. Furthermore, the flash combustion technique permit to have nanoparticles with a dense spinel phase of MgAl 2 O 4 and with lower sintering temperature in less time and with no calcination step. © 2019 The American Ceramic Society

International audience; Attractive for MEMS, PZT thick films are often microstructured on Si supporting platforms to span the gap between ceramics and thin film technologies. Printing process might lead to lower cost than ceramic process to open routes for MEMS applications. In this paper processing by screen-printing of Au/PZT/Au thick-films supported on alumina or completely released from the substrate are described. Investigations of the film microstructures nevertheless show lower densification than those of bulk ceramics. Prior to selective coating deposition, routes to improve the reduction of the film’s porosity are proposed.

Free fatty acid-2 (FFA2) receptor is a G-protein coupled receptor of interest in the development of therapeutics in metabolic and inflammatory disease areas. The discovery and optimization of an N-thiazolylamide carboxylic acid FFA2 agonist scaffold is described. Dual key objectives were to i) evaluate the potential of this scaffold for lead optimization in particular with respect to safety de-risking physicochemical properties, i.e. lipophilicity and aromatic content, and ii) to demonstrate the utility of selected lead analogues from this scaffold in a pertinent in vivo model such as oral glucose tolerance test (OGTT). As such, a concomitant improvement in bioactivity together with lipophilic ligand efficiency (LLE) and fraction sp3 content (Fsp3) parameters guided these efforts. Compound 10 was advanced into studies in mice on the basis of its optimized profile vs initial lead 1 (ΔLLE = 0.3, ΔFsp3 = 0.24). Although active in OGTT, 10 also displayed similar activity in the FFA2-knockout mice. Given this off-target OGTT effect, we discontinued development of this FFA2 agonist scaffold.

The aqueous mixing technique-assisted solid-state method was used to synthesize Ba(Co 0.7 Zn 0.3 ) 1/3 Nb 2/3 O 3 (BCZN) ceramics. The optimum pH of the slurry used for the BCZN synthesis was determined from plots of the Zeta potential (ζ) and the viscosity versus pH. The as-prepared materials were characterized by XRD, TG-DTA, SEM and EDS. The microwave dielectric properties are measured using a network analyzer. Ba 5 Nb 4 O 15 and Ba 8 (Co,Zn) 1 Nb 6 O 24 secondary phases were found on the surface of all samples. The ceramic materials sintered at 1350 °C were found to have a high quality factor Q f of 96132, a high dielectric constant e r of 34.5 and near-zero temperature coefficient of the resonant frequency τ f of 0 ppm/°C measured at 6 GHz.

International audience; For many migratory species, social interactions on migration are poorly known, particularly the extent to which brood siblings remain together, at least during their first post-fledging migration. This study tested the assumption that Black Stork siblings stay together during migration and is the first time that juveniles from the same brood of a Palearctic sub-Saharan migratory stork species have been tracked on migration. Four juveniles from the same brood were followed by satellite tracking, and each dispersed or migrated in a completely different direction to its siblings. The results thus refute the idea that Black Stork siblings remain together on their first migration, but to confirm these new findings, it is important to repeat the study using additional nests.

International audience; In this paper we discuss the production of molecular PAH cations using an ECR ion source and their subsequent cooling studied with an electrostatic storage ring, the Mini-Ring on a time range up to 10 ms. We show that the ECR ion source can produce high currents of small PAH cation, here naphthalene and anthracene cations. Then, we report experimental result for the cooling of three PAH cations (anthracene, naphthalene and pyrene) stored in our compact electrostatic storage ring (the Mini-Ring). We show that the Poincaré recurrent fluorescence plays a major role in the cooling process of those PAH cations. We show that for a given internal energy, the cooling rate is much smaller for pyrene than for anthracene and naphthalene. We conclude that the Poincaré recurrent fluorescence is less efficient due to smaller oscillator strength of the D2-D0 electronic transition for pyrene.

The cooling of naphthalene cations (C 10 H 8 ) + has been studied in a compact electrostatic ion storage ring, the Mini-Ring. A nano second laser pulse of 532 nm (2.33 eV) was used to probe the internal energy distribution every millisecond during the storage time up to 5 ms. The evolution of the internal energy distribution of the stored ions was simulated with a model taking into account the dissociation and the radiative decay processes. Calculated decay curves were fitted to the corresponding laser induced neutral decays. For a laser power of 200 μJ/pulse, a good agreement between experiment and modeling was found using an initial Gaussian energy distribution centered to 5.9 eV and a fluorescence decay rate varying from 200 to 300 s −1 in the energy range from 6 to 7 eV. This fast decay was attributed to the delayed Poincare fluorescence process.

We report on a direct measurement of the Internal Energy Distribution (IED) shift rate of an initially hot polycyclic aromatic hydrocarbon (PAH) molecular ensemble, anthracene cations (C14H10+). The ions were produced in an electron cyclotron resonance (ECR) ion source and stored in an electrostatic ion storage ring, the Mini-Ring. Laser pulses of two wavelengths were sent successively to merge the stored ion bunch at different storage times to enhance the neutral fragment yield due to fast laser induced dissociation. Using this technique, we have been able to determine directly the energy shift rate of the IED, without involving any theoretical simulation or any assumption on dissociation rates, cooling rates, or the initial IED. Theoretical energy shift rates have been estimated from the evolution of simulated IEDs by taking into account the effects of the unimolecular dissociation and two radiative decay mechanisms: the Poincare fluorescence and the infrared vibrational emission. The comparison between the experimental results and the model provides new evidence of the important role of the Poincare fluorescence in the overall cooling process of anthracene cations. Although in the short time range the commonly accepted intuition says that the cooling would result mostly from the dissociation of the hottest ions (depletion cooling), we demonstrate that the Poincare fluorescence is the dominant contribution (about 85%) to the net cooling effect.

Laser-induced breakdown spectroscopy (LIBS) has been applied to classify French wines according to their production regions. The use of the surface-assisted (or surface-enhanced) sample preparation method enabled a sub-ppm limit of detection (LOD), which led to the detection and identification of at least 22 metal and nonmetal elements in a typical wine sample including majors, minors and traces. An ensemble of 29 bottles of French wines, either red or white wines, from five production regions, Alsace, Bourgogne, Beaujolais, Bordeaux and Languedoc, was analyzed together with a wine from California, considered as an outlier. A non-supervised classification model based on principal component analysis (PCA) was first developed for the classification. The results showed a limited separation power of the model, which however allowed, in a step by step approach, to understand the physical reasons behind each step of sample separation and especially to observe the influence of the matrix effect in the sample classification. A supervised classification model was then developed based on random forest (RF), which is in addition a nonlinear algorithm. The obtained classification results were satisfactory with, when the parameters of the model were optimized, a classification accuracy of 100% for the tested samples. We especially discuss in the paper, the effect of spectrum normalization with an internal reference, the choice of input variables for the classification models and the optimization of parameters for the developed classification models.

International audience; Dissociation of doubly charged Anthracene was studied in collisions with a fast 3 keV F+ ion beam. From fragmentation mass spectrum measured in coincidence with the energy deposited in the molecule, we have determined the dissociation rate for the loss of C2H2 and H as a function of energy. The cooling of singly charged Anthracene was studied using a small electrostatic storage ring. The fluorescence emission rate has been determined and compared with a theoretical model.

In this work, we have studied the influence of lithium carbonate (Li2CO3) associated with the vanadium oxide (V2O5) on sintering and dielectrics properties of Ca0.5Sr0.5TiO3 ceramic materials obtained from nanopowder synthesized by sol-gel method. The nanopowder was obtained by controlled mixing of titanium butoxide dissolved in butanol-2 and acetic acid with a saturated aqueous solution of calcium acetate and strontium carbonate and subsequent drying of the formed gel at 80 ?C and calcination at 1100?C. The synthesized nanopowder was mixed with different amount of additives, and then uniaxally pressed and sintered in air atmosphere at temperature determined by dilatomertic measurements. The pure Ca0.5Sr0.5TiO3 sample obtained by this process required a sintering temperature around 1500?C. The addition of Li2CO3 combined with V2O5 improved sinterability and caused a shift of dilatimeric shrinkage curve to much lower temperatures. Thus, dense ceramics (98% of theoretical density) were obtained at sintering temperature ? 1300?C. The effect of adding Li2CO3-V2O5 on the structure of ceramics and the dielectric properties is discussed and show that type I dielectric properties (linear variation of the permittivity) are conserved, but with an increase of dielectric loss.

In the power-to-gas process, hydrogen, produced by water electrolysis, is used as storage for excess, fluctuating renewable electric power. Reconversion of hydrogen back to electricity with the maximum possible efficiency is one pre-requisite to render hydrogen storage technically and economically viable. Pure oxygen is a byproduct in the electrolysis of water. The use of pure oxygen as the oxidant in a polymer electrolyte fuel cell (PEFC) is a possible way of increasing the conversion efficiency of hydrogen to power, by reducing the fuel cell's cathodic kinetic overvoltage, which is the most important energy loss process in low temperature PEFCs. As we demonstrate in this work, when using pure oxygen, either high efficiencies at current densities around 1 A cm−2 are obtained or a very high power density operation (up to 1.6 W cm−2 at cell voltages above 0.62 V) can be reached, giving the technology a broad window of operation and application. The fuel cell stack durability is assessed in accelerated long-term tests of up to 2700 h. The potential of the technology is demonstrated with the realization of a complete 25 kW prototype system delivering a peak efficiency of 69% LHV (57% HHV).

The purpose of this study is the making of multilayer type I capacitors composed of ZnNb2O6 co-sintered with silver electrodes. In order to lower the sintering temperature, we have mixed three commercially available glass frit powders with ZnNb2O6. The sintering behaviours were studied by thermomechanical analysis (TMA). Two additives allowed us to sinter ZnNb2O6 at 900 °C. The sintered ceramic pellets show a type I dielectric behaviour close to the one of pure ZnNb2O6 (e.g.: dielectric constant around 22, resistivity above 1012 Ω. and dielectric losses lower than 10−3). Ceramics were co-sintered with Ag in order to estimate Ag diffusion behaviour. One composition, ZnNb2O6+5 wt% (B2O33ZnO3SiO2) glass frit can be co-sintered at 900 °C with Ag electrodes and leads to type I dielectric properties.

TLQP-21, a peptide derived from VGF (non-acronymic) by proteolytic processing, has been shown to modulate energy metabolism, differentiation, and cellular response to stress. Although extensively investigated, the receptor for this endogenous peptide has not previously been described. This study describes the use of a series of studies that show G protein-coupled receptor-mediated biological activity of TLQP-21 signaling in CHO-K1 cells. Unbiased genome-wide sequencing of the transcriptome from responsive CHO-K1 cells identified a prioritized list of possible G protein-coupled receptors bringing about this activity. Further experiments using a series of defined receptor antagonists and siRNAs led to the identification of complement C3a receptor-1 (C3AR1) as a target for TLQP-21 in rodents. We have not been able to demonstrate so far that this finding is translatable to the human receptor. Our results are in line with a large number of physiological observations in rodent models of food intake and metabolic control, where TLQP-21 shows activity. In addition, the sensitivity of TLQP-21 signaling to pertussis toxin is consistent with the known signaling pathway of C3AR1. The binding of TLQP-21 to C3AR1 not only has effects on signaling but also modulates cellular functions, as TLQP-21 was shown to have a role in directing migration of mouse RAW264.7 cells.

The concept of passive hybrid, i.e. the direct electrical coupling between a fuel cell system and a battery without using a power converter, is presented as a feasible solution for powertrain applications. As there are no DC/DC converters, the passive hybrid is a cheap and simple solution and the power losses in the electronic hardware are eliminated. In such a powertrain topology where the two devices always have the same voltage, the active power sharing between the two energy sources can not be done in the conventional way. As an alternative, control of the fuel cell power by adjusting its operating pressure is elaborated. Only pure H2/O2 fuel cell systems are considered in this approach. Simulation and hardware in the loop (HIL) results for the powertrain show that this hybrid power source is able to satisfy the power demand of an electric vehicle while sustaining the battery state of charge.

International audience; This study shows the importance of controlling the rheological behavior of slurries during attrition milling in aqueous media. Indeed, during grinding, the creation of new surfaces that react with the aqueous dispersing medium leads to modification of the slurry's properties, in particular pH and rheological behavior. The slurry can then flocculate and its viscosity increases. Thus, grinding efficiency can very quickly become null and a “setting” of the slurry in the grinder is sometimes noted. Our approach of the problem is in two steps. First, we determine the optimum dispersion conditions to obtain deflocculated slurries. This is possible by control of the solid load or pH, or by the addition of dispersant in order to enhance electrostatic and/or steric repulsion between particles. The characterization of the dispersion state is also possible with tools such as zetametry and rheology. The second step is to preserve this deflocculated state of dispersion throughout the milling process. This is possible, for example, by maintaining relatively constant the optimal pH value for the slurry. We apply this concept for the grinding of classically used powder oxides TiO2 and Al2O3. To this end, we implement a horizontal attrition mill (dyno‐mill), using different kind of balls: zircon or stabilized yttrium–zirconia with diameters ranging from 0.4 to 1.6 mm. We have observed the grinding efficiency by powder BET specific area measurements, and by DRX and TEM observations. So the grinding is very efficient, starting powders areas of about 10 m2 · g−1 have reached 40 m2 · g−1 after grinding, that is to say, average grains diameter lower than 50 nm.

This work deals with the sensitivity to moisture rate in air of perovskite with general formula YCr (1− x ) Mn x O 3 with x ranging from 0 to 0.8. The combined sensitivity to moisture and temperature let us think the possibility of realizing composite sensors temperature/moisture. This study clearly shows the influence of the Mn content on moisture which affects the working frequency of sensors. Capacitance variation of the most sensitive compositions increases from 100 pF to 1 nF for relative humidity between 20 and 80%. The influence of porosity is also demonstrated.

In this paper, the powertrain sizing of a fuel-cell hybrid vehicle (FCHV) is investigated. The goal is to determine the fuel-cell system (FCS) size, together with the energy storage system (ESS) size, which leads to the lowest hydrogen consumption. The power source (FCS + ESS) capabilities should also respect the vehicle driveability constraints. Batteries and supercapacitors are considered as ESSs. The power management strategy is a global optimization algorithm respecting charge sustaining of the ESS. The impacts of the driving cycle (urban, outer urban, and highway), ESS technology, and vehicle driveability constraints on hydrogen consumption are analyzed in detail.

We present the results of the treatment of 15 adult patients with chronic autoimmune thrombocytopenic purpura with high dose i.v. gammaglobulins. In 11 patients, this treatment produced a remission, complete (platelet counts above 100 times 109/1) in 5, partial (platelet counts between 50 and 100 times 109/1) in 6. In all these patients, the response was transient lasting 2–4 weeks. In 4 patients, no response was observed. We used plasmin-cleaved gammaglobulins which caused rare and mild side effects and gave results similar to those reported with intact human gammaglobulins. The indications of high dose i.v. gamma-globulins in the management of adult patients with autoimmune thrombocytopenic purpura are discussed.

We investigated by Raman spectroscopy (RS) the crystalline quality of CeO2 thin films radio frequency magnetron sputtered on n-type (111) Si substrates from CeO2 target. The deposition temperature was in the range of 200–800 °C. We also realized structural investigations on CeO2 layers after Rapid Thermal Annealing (RTA) performed in the range of 750–1000 °C for 30 s under nitrogen atmosphere. So this study displays that a high-growth temperature and a high post-growth-RTA temperature improves the crystalline structure of the film. In fact, the best crystalline quality, which is close to the CeO2 target taken as a reference, is obtained for a CeO2 layer deposited at 800 °C and post-annealed at 1000 °C for 30 s. Copyright © 2008 John Wiley & Sons, Ltd.

Summary. Tests for a dysimmune state were done in an unselected group of 67 patients with agnogenic myeloid metaplasia (AMM). The results were compared to those of 56 patients with polycythaemia vera (PV). 75% of AMM patients versus 32% of PV patients had various abnormalities. The most frequent disorders among AMM patients were serum antinuclear and anti smooth muscle autoantibodies (10 3% each), a positive test for rheumatoid factor (21 7%), a polyclonal increase in serum immunoglobulin levels (46 8%) or a serum monoclonal component (9 7%), a positive direct Coombs’test (19%), an anti I autoantibody (30%). In AMM patients there was no relationship between age, sex, importance of splenic enlargement, time from diagnosis or treatment and the present of a dysimmunity. Furthermore, in AMM patients, but also in PV patients, it seems that the more frequent and numerous these abnormalities the more severe is the myelofibrosis. Like other previous studies, these results suggest a lymphoid cell involvement in AMM and a role for these immune disorders in the pathogenesis of myelofibrosis.

International audience; Through the dielectric materials used for the making of type I multilayer ceramic capacitors, the ilmenite magnesium titanate MgTiO3 is of particular importance. Yet, it seems difficult to get pure MgTiO3 with a controlled stoichiometry. In order to be able to synthesize it by solid-state reaction, we therefore studied the mixing/grinding behavior of the precursors MgO + TiO2.The evolution versus pH of the zeta potential values of both MgO and TiO2 (anatase) powders shows that it is impossible to get correct pH values allowing a good dispersion state and thus an easy control of the mixing of these two species when considering only electrostatic repulsion. So, we considered to add dispersing agent in order to get a steric dispersion behavior. Rheological characterization of the slurries showed that we were able to get a good dispersion state during the process of mixing/grinding. XRD and SEM/EDX analysis shows the ability of obtaining “pure” MgTiO3 with a controlled stoichiometry after calcination by controlling the rheological behavior of slurries during mixing/grinding.

Electron capture processes in collision between slow X7+ (X = N, O and Ne) ions and C60 fullerene have been investigated using coincident measurements of the number n of ejected electrons, the mass and charge of the multicharged C60 r+ recoil ions and their fragments Cm i+ and the final charge state of the outgoing projectiles X(q-s)+ ( $1 \leqslant s \leqslant q-1$ ). The collision velocity is about 0.4 a.u. The partial cross-sections σr s , corresponding to r electrons transferred to the projectile with only s electrons stabilized, have been measured. Cross-sections for collisions “inside” and those “outside” the C60 cage have been separated by analyzing the kinetic energy of the outgoing projectile. The mean final charge state for frontal collisions has been measured to 3.1, 2.6 and 2.5 for N7+, O7+ and Ne7+ respectively. These results show the importance of the core effect on the stabilisation processes of captured electrons.

We present results on the fragmentation of singly and doubly charged adenine induced by electronic capture processes in collisions with 6 keV F 2+ projectile ions. The results are compared to our previous study at 36 keV collision energy. In these experiments, the initial charge of adenine before fragmentation is determined using a highly selective technique based on triple coincidence measurements between the charge of the outgoing projectile, the time-of-flight of the recoil ions and the number of ejected electrons. For both singly and doubly charged adenine the comparison of the mass spectra at the two energies shows differences in the fragmentation pathways.

We employed a conic-electrode electrostatic ion resonator (ConeTrap) to store the recoil ions ( C 60 r + ) resulting from collision between 56 keV Ar8+ ions and C60 in order to study their stability over a long time range (several milliseconds). The originality of our method, based on the trapping of a single ion to preserve the detection in coincidence of all the products of the collision, is presented in detail. Our results show that C60 ions produced in such collisions are stable in the considered observation time. By employing the ConeTrap as a secondary mass spectrometer in order to let the ions oscillate only for a single period, we have been able to observe delayed evaporation of cold C 60 3 + ions 20 μs after the collision. We interpret quantitatively the relative yields of daughter ions with a cascade model in which the transition rates are estimated via the commonly used Arrhenius law, taking into account the contribution of the radiative decay.

International audience; Fast radiative cooling of anthracene cations (C14H10)+ is studied with a compact electrostatic storage device, the Mini-Ring. The time evolution of the internal energy distribution of the stored ions is probed in a time range from 3 to 7 ms using laser-induced dissociation with 3.49-eV photons. The population decay rate due to radiative emission is measured to vary from 25 to 450s–1 as a function of the excitation energy in the range from 6 to 7.4 eV. After corrections of the infrared emission effect via vibrational transitions, the fluorescence emission rate due to electronic transitions from thermally excited electronic states is estimated and compared with a statistical molecular approach. In the considered internal energy range, the radiative cooling process is found to be dominated by the electronic transition, in good agreement with our previous work [S. Martin et al., Phys. Rev. Lett. 110, 063003 (2013)] focused on a narrower energy range.

The impact of the microwave annealing (MA) on the crystallinity and on the electrical properties of CeO 2 thin films has been investigated by Raman Spectroscopy, capacitance–voltage ( C – V ) measurements and current–voltage ( I – V ) measurements. This paper highlights the influence of the temperature, time, and atmosphere used for the MA on the crystallinity, the surface quality, and the oxidation state of Ce of CeO 2 thin films. At the same time, the impact of microwave annealing on the flatband voltage ( V FB ) and the interface traps density ( D it ) is studied by C – V measurements. Moreover, the leakage current is compared before and after the microwave annealing. Therefore, this paper shows a sharp improvement of the CeO 2 film crystallinity and a decrease in leakage current after a microwave annealing performed at 900 °C for 5 min under nitrogen atmosphere. To our knowledge, it is the first time that the impact of MA on CeO 2 films is reported.