Electrodeposition of arrays of Ru, Pt, and PtRu Alloy 1D metallic nanostructures

Arrays of Ru, Pt, and PtRu one dimensional 1D nanowires NWs and nanotubes NTs were prepared by electrodeposition through the porous structure of an anodic aluminum oxide AAO membrane. In each case, micrometer-long NW and NT were formed with an outer diameter of ca. 200 nm, close to the interior diameter of the porous AAO membrane. Arrays of NW and NT can be formed by varying the metallic salt concentration, the applied potential, and the conductivity of the electrolyte. The Ru and Pt deposition rates were measured in the various deposition conditions, using an electrochemical quartz crystal microbalance. The mechanisms responsible for the formation of Ru and Pt NW and NT are discussed based on the observed deposition rates and models found in the literature. Finally, it is shown that arrays of PtRu alloy NT and NW can be readily prepared and their compositions can be varied over the whole compositional range by changing the metallic salt concentration of the electrodeposition bath

On the origin of the extra capacity at low potential in materials for Li batteries reacting through conversion reaction

The possibility of interfacial storage at low potential for electrode materials reacting through conversion reactions was evaluated. The amount of charge that could be stored through the proposed interfacial mechanism was estimated for a range of different materials and found to be much lower than those observed experimentally. Moreover, the slope of the potential decay and the influence of the current in the extent of stored capacity for experiments carried out in composite electrodes containing Co3O4 are not consistent with a capacitive-like mechanism. In summary, no evidence for capacitive storage could be found, our results being in agreement with the process taking place at low potential being solely related to electrolyte decomposition

Electrochemical Method for Direct Deposition of Nanometric Bismuth and Its Electrochemical Properties vs Li

We report that nanometric bismuth can directly be electrodeposited at room temperature without the use of a nanoporous template. The morphology, microstructure, and purity of the as-prepared electrodeposits were characterized by scanning electron microscopy, transmission electron microscopy, and infrared spectroscopy. Typically, well-crystallized nanometer-sized particles of Bi ranging from 10 to 20 nm are obtained. The key to success of such a process lies in the electrochemical coreduction of pyrocatechol violet during the bismuth deposition, which disturbs the electrocrystallization process. As a first possible application, we show that Bi/Cu nanoarchitectured electrodes exhibit interesting rate capabilities when used as electrode material vs Li

Gestion intégrée des ignames sauvages de l'Afrique de l'Ouest : cas de Dioscorea praehensilis au Bénin

Dans les agrosystèmes traditionnels, les ignames cultivées Dioscorea rotundata sont multipliées par propagation végétative. Les aléas environnementaux et d'origine anthropique constituent un risque pour leur diversité génétique. Or de récents travaux en Afrique de l'Ouest montrent que des ignames sauvages D. abyssinica Hochst ex Kunth et D. praehensilis Benth. ainsi que des hybrides entre ignames cultivées et sauvages sont introduites dans le pool cultivé via une pratique paysanne appelée ennoblissement. Ces espèces sauvages contribuent ainsi à l'enrichissement de la diversité génétique des ignames cultivées. Au Bénin, les ignames sauvages, en particulier D. praehensilis, sont menacées de disparition dans leurs aires de distribution à cause de la pression anthropique. Leur conservation in-situ est primordiale. Or, elles ne sont pas intégrées dans les programmes de protection mis en place dans certaines forêts. (Résumé d'auteur

Ventricular fibrillation in experimental hypothermic cardiac surgery, the evaluation of antifibrillary agents

Thesis (M.A.)--Boston Universit

Effect of bicarbonate and lactate buffer on glucose and lactate metabolism during hemodiafiltration in patients with multiple organ failure

Objective: To compare the effects of sodium bicarbonate and lactate for continuous veno-venous hemodiafiltration (CVVHDF) in critically ill patients. Design and settings: Prospective crossed-over controlled trial in the surgical and medical ICUs of a university hospital. Patients: Eight patients with multiple organ dysfunction syndrome (MODS) requiring CVVHDF. Intervention: Each patient received the two buffers in a randomized sequence over two consecutive days. Measurements and results: The following variables were determined: acid-base parameters, lactate production and utilization (13C lactate infusion), glucose turnover (6,62H2-glucose), gas exchange (indirect calorimetry). No side effect was observed during lactate administration. Baseline arterial acid-base variables were equal with the two buffers. Arterial lactate (2.9 versus 1.5mmol/l), glycemia (+18%) and glucose turnover (+23%) were higher in the lactate period. Bicarbonate and glucose losses in CVVHDF were substantial, but not lactate elimination. Infusing 13C lactate increased plasma lactate levels equally with the two buffers. Lactate clearance (7.8±0.8 vs 7.5±0.8ml/kg per min in the bicarbonate and lactate periods) and endogenous production rates (14.0±2.6 vs 13.6±2.6mmol/kg per min) were similar. 13C lactate was used as a metabolic substrate, as shown by 13CO2 excretion. Glycemia and metabolic rate increased significantly and similarly during the two periods during lactate infusion. Conclusion: Lactate was rapidly cleared from the blood of critically ill patients without acute liver failure requiring CVVHDF, being transformed into glucose or oxidized. Lactate did not exert undesirable effects, except moderate hyperglycemia, and achieved comparable effects on acid-base balance to bicarbonat

Existential witness extraction in classical realizability and via a negative translation

We show how to extract existential witnesses from classical proofs using Krivine's classical realizability---where classical proofs are interpreted as lambda-terms with the call/cc control operator. We first recall the basic framework of classical realizability (in classical second-order arithmetic) and show how to extend it with primitive numerals for faster computations. Then we show how to perform witness extraction in this framework, by discussing several techniques depending on the shape of the existential formula. In particular, we show that in the Sigma01-case, Krivine's witness extraction method reduces to Friedman's through a well-suited negative translation to intuitionistic second-order arithmetic. Finally we discuss the advantages of using call/cc rather than a negative translation, especially from the point of view of an implementation.Comment: 52 pages. Accepted in Logical Methods for Computer Science (LMCS), 201

Generalised Mutual Information: a Framework for Discriminative Clustering

In the last decade, recent successes in deep clustering majorly involved the Mutual Information (MI) as an unsupervised objective for training neural networks with increasing regularisations. While the quality of the regularisations have been largely discussed for improvements, little attention has been dedicated to the relevance of MI as a clustering objective. In this paper, we first highlight how the maximisation of MI does not lead to satisfying clusters. We identified the Kullback-Leibler divergence as the main reason of this behaviour. Hence, we generalise the mutual information by changing its core distance, introducing the Generalised Mutual Information (GEMINI): a set of metrics for unsupervised neural network training. Unlike MI, some GEMINIs do not require regularisations when training as they are geometry-aware thanks to distances or kernels in the data space. Finally, we highlight that GEMINIs can automatically select a relevant number of clusters, a property that has been little studied in deep discriminative clustering context where the number of clusters is a priori unknown.Comment: Submitted for review at the IEEE Transactions on Pattern Analysis and Machine Intelligence. This article is an extension of an original NeurIPS 2022 article [arXiv:2210.06300

Les caractères du détritisme paléogène aux abords du Massif du Pelvoux (Alpes externes méridionales)

Mémoire HS n° 13 - Géologie Alpine : Le détritisme dans le Sud-Est de la France - Colloque Association des Géologues du Sud-est - Grenoble 11-12 décembre 1986Aux abords du Pelvoux, la sédimentation tertiaire montre des apports détritiques importants. La nature et la répartition du flux terrigène sont contrôlées par la nature du substratum qui subit la transgression nummulitique ainsi que par le jeu d ' accidents synsédimentaires. Partout, la base de la série, ainsi que son couronnement par les couches détritiques terminales (Grès de Saint-Disdier ; Grès du Champsaur et Olistostrome) attestent de ce détritisme. Néanmoins le SE et l'E du Pelvoux montrent souvent un détritisme plus important, soit que la totalité de la série -ou presque- se trouve représentée par les seuls Grès du Champsaur, soit que le détritisme grossier (à olistolites souvent) envahisse la série paléogène sur pratiquement toute sa hauteur

The modulation of somatosensory resonance by psychopathic traits and empathy

A large number of neuroimaging studies have shown neural overlaps between first-hand experiences of pain and the perception of pain in others. This shared neural representation of vicarious pain is thought to involve both affective and sensorimotor systems. A number of individual factors are thought to modulate the cerebral response to other's pain. The goal of this study was to investigate the impact of psychopathic traits on the relation between sensorimotor resonance to other's pain and self-reported empathy. Our group has previously shown that a steady-state response to non-painful stimulation is modulated by the observation of other people's bodily pain. This change in somatosensory response was interpreted as a form of somatosensory gating (SG). Here, using the same technique, SG was compared between two groups of 15 young adult males: one scoring very high on a self-reported measure of psychopathic traits [60.8 ± 4.98; Levenson's Self-Report Psychopathy Scale (LSRP)] and one scoring very low (42.7 ± 2.94). The results showed a significantly greater reduction of SG to pain observation for the high psychopathic traits group compared to the low psychopathic traits group. SG to pain observation was positively correlated with affective and interpersonal facet of psychopathy in the whole sample. The high psychopathic traits group also reported lower empathic concern (EC) scores than the low psychopathic traits group. Importantly, primary psychopathy, as assessed by the LSRP, mediated the relation between EC and SG to pain observation. Together, these results suggest that increase somatosensory resonance to other's pain is not exclusively explained by trait empathy and may be linked to other personality dimensions, such as psychopathic traits