Cu-Al-Ni Shape Memory Single Crystal Wires with High Transformation Temperature

CN-250X is a new material with higher performance than Nickel-Titanium Shape Memory Alloy (SMA). For space mechanisms, the main disadvantage of Nickel-Titanium Shape Memory Alloy is the limited transformation temperature. The new CN-250X Nimesis alloy is a Cu-Al-Ni single crystal wire available in large quantity because of a new industrial process. The triggering of actuators made with this Cu-Al-Ni single crystal wire can range from ambient temperature to 200 C in cycling and even to 250 C in one-shot mode. Another advantage of CN-250X is a better shape recovery (8 to 10%) than Ni-Ti (6 to 7%). Nimesis is the first company able to produce this type of material with its new special industrial process. A characterization study is presented in this work, including the two main solicitation modes for this material: tensile and torsion. Different tests measure the shape recovery of Cu-Al-Ni single crystals wires during heating from room temperature to a temperature higher than temperature of end of martensitic transformation

Space grease lubrication modeling: A discrete element approach

International audienceThe tribological behavior of space grease is investigated with the Discrete Element Method. In the first step, the grease is described as a collection of particles of two kinds (oil and PTFE) in interaction. The development of the Grease Discrete Element Model (GDEM) used here, is based on rheometer-like characterizations. In the second step, the GDEM is subjected to tribometer-like conditions to investigate grease flow mechanisms and the role of the thickener (PTFE) in lubrication. The tribological behavior of grease seems to be controlled by the coupled influence of both granulometric (thickener particle sizes) and physico-chemical (interaction law) parameters. These results provide the starting point for identifying the parameters on which to act to reformulate greases

Allogeneic transplantation in acute myelogenous leukemia: a comprehensive single institution's experience

Debates on the role and timing of allogeneic hemtopoietic stem cell transplantation (HSCT) in acute myelogenous leukemia (AML) have persisted for decades. Time to transplant introduces an immortal time and current treatment algorithm mainly relies on the European LeukemiaNet disease risk classification. Previous studies are also limited to age groups, remission status and other ill-defined parameters. We studied all patients at diagnosis irrespective of age and comorbidities to estimate the cumulative incidence and potential benefit or disadvantage of HSCT in a single center. As a time-dependent covariate, HSCT improved overall survival in intermediate- and poor-risk patients (hazard ratio =0.51; P=0.004). In goodrisk patients only eight were transplanted in first complete remission. Overall, the 4-year cumulative incidence of HSCT was only 21.9% but was higher (52.1%) for patients in the first age quartile (16-57 years old) and 26.4% in older patients (57-70 years old) (P<0.001). It was negligible in patients older than 70 years reflecting our own transplant policy but also barriers to transplantation (comorbidities and remission status). However, HSCT patients need to survive, be considered eligible both by the referring and the HSCT physicians and have a suitable donor to get transplantation. We, thus, comprehensively analyzed the complete decision-making and outcome of all our AML patients from diagnosis to last followup to decipher how patient allocation and therapy inform the value of HSCT. The role of HSCT in AML is shifting with broad access to different donors including haploidentical ones. Thus, it may (or may not) lead to increased numbers of allogeneic HSCT in AML in adults

Data descriptor: a global multiproxy database for temperature reconstructions of the Common Era

Reproducible climate reconstructions of the Common Era (1 CE to present) are key to placing industrial-era warming into the context of natural climatic variability. Here we present a community-sourced database of temperature-sensitive proxy records from the PAGES2k initiative. The database gathers 692 records from 648 locations, including all continental regions and major ocean basins. The records are from trees, ice, sediment, corals, speleothems, documentary evidence, and other archives. They range in length from 50 to 2000 years, with a median of 547 years, while temporal resolution ranges from biweekly to centennial. Nearly half of the proxy time series are significantly correlated with HadCRUT4.2 surface temperature over the period 1850-2014. Global temperature composites show a remarkable degree of coherence between high-and low-resolution archives, with broadly similar patterns across archive types, terrestrial versus marine locations, and screening criteria. The database is suited to investigations of global and regional temperature variability over the Common Era, and is shared in the Linked Paleo Data (LiPD) format, including serializations in Matlab, R and Python. (TABLE) Since the pioneering work of D'Arrigo and Jacoby1-3, as well as Mann et al. 4,5, temperature reconstructions of the Common Era have become a key component of climate assessments6-9. Such reconstructions depend strongly on the composition of the underlying network of climate proxies10, and it is therefore critical for the climate community to have access to a community-vetted, quality-controlled database of temperature-sensitive records stored in a self-describing format. The Past Global Changes (PAGES) 2k consortium, a self-organized, international group of experts, recently assembled such a database, and used it to reconstruct surface temperature over continental-scale regions11 (hereafter, ` PAGES2k-2013'). This data descriptor presents version 2.0.0 of the PAGES2k proxy temperature database (Data Citation 1). It augments the PAGES2k-2013 collection of terrestrial records with marine records assembled by the Ocean2k working group at centennial12 and annual13 time scales. In addition to these previously published data compilations, this version includes substantially more records, extensive new metadata, and validation. Furthermore, the selection criteria for records included in this version are applied more uniformly and transparently across regions, resulting in a more cohesive data product. This data descriptor describes the contents of the database, the criteria for inclusion, and quantifies the relation of each record with instrumental temperature. In addition, the paleotemperature time series are summarized as composites to highlight the most salient decadal-to centennial-scale behaviour of the dataset and check mutual consistency between paleoclimate archives. We provide extensive Matlab code to probe the database-processing, filtering and aggregating it in various ways to investigate temperature variability over the Common Era. The unique approach to data stewardship and code-sharing employed here is designed to enable an unprecedented scale of investigation of the temperature history of the Common Era, by the scientific community and citizen-scientists alike

Data Descriptor: A global multiproxy database for temperature reconstructions of the Common Era

Reproducible climate reconstructions of the Common Era (1 CE to present) are key to placing industrial-era warming into the context of natural climatic variability. Here we present a community-sourced database of temperature-sensitive proxy records from the PAGES2k initiative. The database gathers 692 records from 648 locations, including all continental regions and major ocean basins. The records are from trees, ice, sediment, corals, speleothems, documentary evidence, and other archives. They range in length from 50 to 2000 years, with a median of 547 years, while temporal resolution ranges from biweekly to centennial. Nearly half of the proxy time series are significantly correlated with HadCRUT4.2 surface temperature over the period 1850-2014. Global temperature composites show a remarkable degree of coherence between high-and low-resolution archives, with broadly similar patterns across archive types, terrestrial versus marine locations, and screening criteria. The database is suited to investigations of global and regional temperature variability over the Common Era, and is shared in the Linked Paleo Data (LiPD) format, including serializations in Matlab, R and Python.(TABLE)Since the pioneering work of D'Arrigo and Jacoby1-3, as well as Mann et al. 4,5, temperature reconstructions of the Common Era have become a key component of climate assessments6-9. Such reconstructions depend strongly on the composition of the underlying network of climate proxies10, and it is therefore critical for the climate community to have access to a community-vetted, quality-controlled database of temperature-sensitive records stored in a self-describing format. The Past Global Changes (PAGES) 2k consortium, a self-organized, international group of experts, recently assembled such a database, and used it to reconstruct surface temperature over continental-scale regions11 (hereafter, ` PAGES2k-2013').This data descriptor presents version 2.0.0 of the PAGES2k proxy temperature database (Data Citation 1). It augments the PAGES2k-2013 collection of terrestrial records with marine records assembled by the Ocean2k working group at centennial12 and annual13 time scales. In addition to these previously published data compilations, this version includes substantially more records, extensive new metadata, and validation. Furthermore, the selection criteria for records included in this version are applied more uniformly and transparently across regions, resulting in a more cohesive data product.This data descriptor describes the contents of the database, the criteria for inclusion, and quantifies the relation of each record with instrumental temperature. In addition, the paleotemperature time series are summarized as composites to highlight the most salient decadal-to centennial-scale behaviour of the dataset and check mutual consistency between paleoclimate archives. We provide extensive Matlab code to probe the database-processing, filtering and aggregating it in various ways to investigate temperature variability over the Common Era. The unique approach to data stewardship and code-sharing employed here is designed to enable an unprecedented scale of investigation of the temperature history of the Common Era, by the scientific community and citizen-scientists alike

New homogeneous gelled oils for space mechanisms lubrication

International audienceNew homogeneous gelled oils for space mechanisms lubrication

CONMEMORACIÓN DEL CINCUENTENARIO DEL CABILDO DE GRAN CANARIA PRESIDIDA POR EL MINISTRO SOLÍS EN EL SALÓN DE PLENOS [Material gráfico]

Copia digital. Madrid : Ministerio de Educación, Cultura y Deporte. Subdirección General de Coordinación Bibliotecaria, 201

Tribological Performance of Gelled Oils for Space Mechanisms Lubrication

International audienceBearing lubrication is an important point in various fields, particularly in space applications where the lubricants must maintain their performance in very low temperatures and under high vacuum.&nbsp; Grease based on PTFE/MoS2 fillers are currently used. However, these greases exhibit frictional torque peaks in bearings at low speeds [1] due to the composition and structure of the grease [1, 2].A good alterna-tive is to use grease-like products such as gelled oils with higher viscosity than the oil alone [3]. The rheological and tribological tests performed on two new gelled oils formulated showed performance equivalent or even superior to the reference grease. The new lubricants performance (friction torque, noise and endurance life) are also evaluated with an innovative test bench which directly assess gelled oils in bearings in high vacuum environment

Le manuscrit franciscain retrouvé

Textes issus du colloque organisé du 20 au 22 septembre 2017 à Paris sous l'égide de l'Institut de Recherche et d'Histoire des Textes et de la Bibliothèque nationaleInternational audienceMinuscule livre de poche (12 x 8 cm), le manuscrit mis en vente en 2014 par une galerie parisienne, fruste, usé, dépenaillé et à peine déchiffrable, a pourtant suscité un extraordinaire engouement international et d’intenses investigations scientifiques. Ce libricino qu’un frère itinérant, disciple de François d’Assise, glissait dans sa besace voici huit cents ans fut, en quelques mois, acquis par la Bibliothèque nationale de France, numérisé et mis en ligne sur Gallica pour être offert à l’expertise internationale. Quelques années de recherche plus tard, les 122 petits feuillets n’ont pas livré tous leurs secrets, mais les spécialistes ici réunis, experts en physique, chimie, biologie, paléographie, codicologie, philologie, histoire ou théologie, ont opéré des avancées décisives. Ce recueil contient non seulement une Vie inédite de saint François (1181-1226) rédigée dans les années 1230, mais aussi divers sermons connus ou inédits d’Antoine de Padoue, un commentaire au Pater noster où vibre peut-être la ferveur du Poverello en personne, des extraits, des florilèges ou la copie d’œuvres entières comme les étranges Révélations du pseudo-Méthode. Trésor historique inestimable, il est aussi un «objet total» qu’il faut observer, sonder, explorer, pour extraire toutes les informations que recèlent ses matériaux, sa fabrication, son usage. Cet attachant recueil constitue un témoignage exceptionnel des préoccupations et de la sensibilité d’un petit groupe de Frères mineurs, au lendemain de la disparition de leur fondateur. Les experts réunis offrent ici les premiers résultats scientifiques de leurs études. Peut-être le plus important de leurs acquis est-il le dépassement du clivage entre sciences dures et sciences humaines au service d’une recherche faite de rigueur et d’inventivité

Le manuscrit franciscain retrouvé

Textes issus du colloque organisé du 20 au 22 septembre 2017 à Paris sous l'égide de l'Institut de Recherche et d'Histoire des Textes et de la Bibliothèque nationaleInternational audienceMinuscule livre de poche (12 x 8 cm), le manuscrit mis en vente en 2014 par une galerie parisienne, fruste, usé, dépenaillé et à peine déchiffrable, a pourtant suscité un extraordinaire engouement international et d’intenses investigations scientifiques. Ce libricino qu’un frère itinérant, disciple de François d’Assise, glissait dans sa besace voici huit cents ans fut, en quelques mois, acquis par la Bibliothèque nationale de France, numérisé et mis en ligne sur Gallica pour être offert à l’expertise internationale. Quelques années de recherche plus tard, les 122 petits feuillets n’ont pas livré tous leurs secrets, mais les spécialistes ici réunis, experts en physique, chimie, biologie, paléographie, codicologie, philologie, histoire ou théologie, ont opéré des avancées décisives. Ce recueil contient non seulement une Vie inédite de saint François (1181-1226) rédigée dans les années 1230, mais aussi divers sermons connus ou inédits d’Antoine de Padoue, un commentaire au Pater noster où vibre peut-être la ferveur du Poverello en personne, des extraits, des florilèges ou la copie d’œuvres entières comme les étranges Révélations du pseudo-Méthode. Trésor historique inestimable, il est aussi un «objet total» qu’il faut observer, sonder, explorer, pour extraire toutes les informations que recèlent ses matériaux, sa fabrication, son usage. Cet attachant recueil constitue un témoignage exceptionnel des préoccupations et de la sensibilité d’un petit groupe de Frères mineurs, au lendemain de la disparition de leur fondateur. Les experts réunis offrent ici les premiers résultats scientifiques de leurs études. Peut-être le plus important de leurs acquis est-il le dépassement du clivage entre sciences dures et sciences humaines au service d’une recherche faite de rigueur et d’inventivité