Preparation and electrical properties of dense micro-cermets made of nickel ferrite and metallic copper

Dense micro-cermets made of nickel ferrites and copper micrometric particles were obtained from partial reduction under hydrogenated atmosphere at 350 C of mixed copper nickel ferrites, and sintering in nitrogen at 980 C. The small copper particles are homogeneous in size and well dispersed in the spinel oxide matrix. No exudation of copper metal was observed after sintering. The micro-cermets prepared are semi-conducting materials with electrical conductivity lying from 44 to 130 S/cm at 980 C. Their overall characteristics make them interesting for inert anodes dedicated to aluminium electrolysis in melted cryolite

Flow and fracture in water-saturated, unconstrained granular beds

International audienceSpecialty section: This article was submitted to Interdisciplinary Physics, a section of the journal Frontiers in Physics The injection of gas in a liquid-saturated granular bed gives rise to a wide variety of invasion patterns. Many studies have focused on constrained porous media, in which the grains are fixed in the bed and only the interstitial fluid flows when the gas invades the system. With a free upper boundary, however, the grains can be entrained by the ascending gas or fluid motion, and the competition between the upward motion of grains and sedimentation leads to new patterns. We propose a brief review of the experimental investigation of the dynamics of air rising through a water-saturated, unconstrained granular bed, in both two and three dimensions. After describing the invasion pattern at short and long time, a tentative regime-diagram is proposed. We report original results showing a dependence of the fluidized zone shape, at long times, on the injection flow rate and grain size. A method based on image analysis makes it possible to detect not only the fluidized zone profile in the stationary regime, but also to follow the transient dynamics of its formation. Finally, we describe the degassing dynamics inside the fluidized zone, in the stationary regime. Depending on the experimental conditions, regular bubbling, continuous degassing, intermittent regime or even spontaneous flow-to-fracture transition are observed

Gas-induced fluidization of mobile liquid-saturated grains

International audienceGas invasion in liquid-saturated sands exhibits different morphologies and dynamics. For mobile beds, the repeated rise of gas through the layer leads to the growth of a fluidized zone, which reaches a stationary shape. Here, we present experimental results characterizing the evolution of the fluidized region as a function of the gas-flow rate and grain size. We introduce a new observable, the flow density, which quantifies the motion of the grains in the system. The growth of the fluidized zone is characterized by a spatiotemporal analysis, which provides the stabilization time, τ_s. In the stationary regime, we report two main contributions to motion in the fluidized region: the central gas rise and a convective granular motion. Interestingly, a static model with a fixed porous network accounts for the final shape of the invasion zone. We propose an explanation where the initial gas invasion weakens the system and fixes since the early stage the morphology of the fluidized zone

La Gestion Dynamique des déchets (GDD) : élaboration d'une approche intégrée d'aide à la décision visant à soutenir une gestion systémique et évolutive des déchets

International audienceEn raison des impacts sociaux, économiques et environnementaux associés à la gestion des déchets, il est nécessaire de favoriser les prises de décision qui intègrent chacun de ces aspects. Actuellement, les approches préconisées sont plutôt statiques et linéaires dans leur application, elles ne permettent pas une utilisation optimale des matières disponibles. En conséquence, le choix des technologies pour la gestion des déchets repose souvent sur des paramètres fixes, alors que les systèmes sont en constante évolution. De plus, la validité de prioriser une technologie est directement liée aux impacts associés aux longueurs de trajets, aux modes de transports et aux caractéristiques des routes empruntées. Cependant, les outils disponibles négligent cet aspect dynamique qui est crucial pour réduire la charge des systèmes étudiés. Dans le but d'assurer une gestion durable et dynamique des déchets, la GDD propose une nouvelle approche évolutive permettant d'assurer une alimentation constante vers les technologies favorables dans un système. Pour y parvenir, la GDD repose sur la loi de la conservation de l'énergie qui permet d'équilibrer un réseau tout en considérant les contraintes associées aux transports. Afin de démontrer la portée de la GDD, cet article décrit l'approche, puis présente un exemple d'application

Neurological Disorders in Primary Sjögren's Syndrome.

International audienceSjögren's syndrome is an autoimmune disease characterized by an autoimmune exocrinopathy involving mainly salivary and lacrimal glands. The histopathological hallmark is periductal lymphocytic infiltration of the exocrine glands, resulting in loss of their secretory function. Several systemic manifestations may be found in patients with Sjögren's syndrome including neurological disorders. Neurological involvement ranges from 0 to 70% among various series and may present with central nervous system and/or peripheral nervous system involvement. This paper endeavors to review the main clinical neurological manifestations in Sjögren syndrome, the physiopathology, and their therapeutic response

Women in radiology: gender diversity is not a metric-it is a tool for excellence.

Women in Focus: Be Inspired was a unique programme held at the 2019 European Congress of Radiology that was structured to address a range of topics related to gender and healthcare, including leadership, mentoring and the generational progression of women in medicine. In most countries, women constitute substantially fewer than half of radiologists in academia or private practice despite frequently accounting for at least half of medical school enrolees. Furthermore, the proportion of women decreases at higher academic ranks and levels of leadership, a phenomenon which has been referred to as a "leaky pipeline". Gender diversity in the radiologic workplace, including in academic and leadership positions, is important for the present and future success of the field. It is a tool for excellence that helps to optimize patient care and research; moreover, it is essential to overcome the current shortage of radiologists. This article reviews the current state of gender diversity in academic and leadership positions in radiology internationally and explores a wide range of potential reasons for gender disparities, including the lack of role models and mentorship, unconscious bias and generational changes in attitudes about the desirability of leadership positions. Strategies for both individuals and institutions to proactively increase the representation of women in academic and leadership positions are suggested. KEY POINTS: • Gender-diverse teams perform better. Thus, gender diversity throughout the radiologic workplace, including in leadership positions, is important for the current and future success of the field. • Though women now make up roughly half of medical students, they remain underrepresented among radiology trainees, faculty and leaders. • Factors leading to the gender gap in academia and leadership positions in Radiology include a lack of role models and mentors, unconscious biases, other societal barriers and generational changes

Cation Involvement in Telomestatin Binding to G-Quadruplex DNA

The binding mode of telomestatin to G-quadruplex DNA has been investigated using electrospray mass spectrometry, by detecting the intact complexes formed in ammonium acetate. The mass measurements show the incorporation of one extra ammonium ion in the telomestatin complexes. Experiments on telomestatin alone also show that the telomestatin alone is able to coordinate cations in a similar way as a crown ether. Finally, density functional theory calculations suggest that in the G-quadruplex-telomestatin complex, potassium or ammonium cations are located between the telomestatin and a G-quartet. This study underlines that monovalent cation coordination capabilities should be integrated in the rational design of G-quadruplex binding ligands

A difluorenyl-carbo-cyclohexadiene: prospective chromophore for two-photon absorption

For the purpose of outlining structure-property relationships for two-photon absorption (2PA), a "s-locked" carbo-cyclohexadiene with two fluorenyl substituents has been envisaged for comparison with previously studied aromatic carbo-benzene and non-aromatic carbo-quinoid congeners. A representative where the C10-π-conjugated fluorenyl moieties are also connected by a C8-π-insulating 3,6‐dimethoxy‐3,6‐bis(trifluoromethyl)octa‐1,4,7‐triyn-1,8-diyl edge has thus been synthesized in four steps from known C8F triyne and C10 triynyldial, through a [8F+10] cyclization process. In spite of a relatively strong absorbance (e = 84 800 L.mol-1.cm-1 at 634 nm), the non-vanishing green fluorescence (at 533 nm) of the chromophore should allow measurements of the 2PA cross section by both the TPEF and Z-scan methods

Hybrid system to analyze user's behaviour

The evolution of ambient intelligence systems has allowed for the development of adaptable systems. These systems trace user's habits in an automatic way and act accordingly, resulting in a context aware system. The goal is to make these systems adaptable to the user's environment, without the need for their direct interaction. This paper proposes a system that can learn from users' behavior. In order for the system to perform effectively, an adaptable multi agent system is proposed and the results are compared with the use of several classifiers

Choriocarcinome Métastatique Diagnostiqué Et Pris En Charge Aux Urgences Dans Un Pays À Faible Ressources

Le choriocarcinome est une tumeur rare à fort potentiel métastatique pouvant résulter de la dégénérescence d’une môle hydatiforme. Vu au stade de métastase pulmonaire, un tableau de détresse respiratoire inaugural oriente le malade aux urgences. Nous rapportons le cas d’une patiente âgée de 31 ans vivant en milieu rural dans un pays à faibles ressources, évacuée en urgence dans le centre hospitalier de référence pour une détresse respiratoire simulant une pneumopathie aigue grave. Elle présente une anémie sévère à 23g/L d’hémoglobine et un saignement vaginal minime. Les examens paracliniques faisaient découvrir des métastases pulmonaire et hépatique d’un choriocarcinome gestationnel. Le retard de diagnostic associé à une absence de suivi régulier clinique, biologique et échographique met en jeu le pronostic vital d’une telle patiente. Une prise en charge adéquate respiratoire et hémodynamique en soins intensifs associée à une polychimiothérapie et une éventuelle chirurgie améliorerait le pronostic de la patiente.  Choriocarcinoma is a rare tumour with high metastatic potential that can result from the degeneration of a hydatiform mole. Seen at the stage of pulmonary metastasis, an inaugural respiratory distress chart directs the patient to the emergency room. We report the case of a 31-year-old patient living in rural areas in a low-resource country, rushed to the referral hospital for respiratory distress simulating severe acute lung disease. She has severe anaemia at 23g/L of hemoglobin and minimal vaginal bleeding. Paraclinical examinations revealed pulmonary and liver metastases of a gestational choriocarcinoma. Delayed diagnosis associated with a lack of regular clinical, biological and ultrasound follow-up involves the life-threatening prognosis of such a patient. An adequate respiratory and hemodynamic management in intensive care combined with polychemotherapy and possible surgery would improve the patient's prognosis