Isabel Yaya. The Two Faces of Inca History. Dualism in the Narratives and Cosmology of Ancient Cuzco

Bien qu’il aborde un sujet déjà traité à plusieurs reprises depuis des décennies, le livre The Two Faces of Inca History: Dualism in the Narratives and Cosmology of Ancient Cuzco d’Isabel Yaya propose une approche innovante du dualisme dans la société inca qui mérite de ne pas passer inaperçu des spécialistes et ni des néophytes. Cette approche pluridisciplinaire issue de l’anthropologie historique et dans une moindre mesure de la philologie se fonde sur des prémisses dérivées du principe dum..

Relationship between mechanical properties and microstructure of yttria stabilized zirconia ceramics densified by Spark Plasma Sintering

Yttria stabilized zirconia ceramics are well known in the field of thermal barrier coatings due to their high ability to thermally insulate hot metallic parts of turbo-engines. The present work is focused on the mechanical properties and the fracture behavior of such materials shaped by Spark Plasma Sintering.1 Two types of powders have been used: i) the first one is a commercial powder made of micrometric spheroidal agglomerates of nano-crystallites (Tosoh), and ii) the second one is a home-made Sol-Gel powder 2 consisting of dense agglomerates of micrometric non-spherical crystallites. Both powders were shaped by Spark Plasma Sintering. The microstructures and mechanical properties of the various samples were characterized for different porosity rates and composition. The adjustment of several SPS processing parameters such as the temperature and the applied pressure allowed to obtain ceramics with a porosity in the range from 0 to 50 % vol. with oriented microstructure. Please click Additional Files below to see the full abstract

Relationship between mechanical properties and microstructure of yttria stabilized zirconia ceramics densified by spark plasma sintering

Porous ceramics are widely used for many applications such as filters, insulators, electrodes for SOFC, membranes or bone scaffolds, with porosity in the typically range of 20–50%vol. The functionality of those materials comes at the expense of the degradation of their mechanical properties which are highly impacted by the rate, distribution, shape and size of the porosity. Among them tetragonal stabilized zirconia (TSZ) is one of the most industrially used; it is sometime called: “the ceramic steel” since in its dense state it exhibits the highest toughness for ceramics. It is known that the porosity has a huge impact on the thermo-mechanical properties of refractory ceramics as Yittria Stabilized Zirconia (YSZ). This study aims to capitalize the mechanical properties as a function of porosity to provide future applications and ensure the behavior in service of thermal barrier coating. In the present paper, the correlation between the microstructure and the mechanical properties such as Young modulus, hardness and strength of YSZ ceramics obtained by Spark Plasma Sintering (SPS) was investigated. Two types of YSZ powder, a nanometric one from Tosoh and a micrometric one obtained by sol-gel route were studied to prepare homogeneous mesoporous or oriented macroporous microstructure by partial sintering. SPS parameters have been determined and optimized to manage the porosity rate. Furthermore, a bimodal microstructure can be obtained, by mixing both powders, allowing the formation of linking bridges between the microporous zone and the nanopowder during sintering. The macroporous ceramics have lower Young modulus, hardness and strength than mesoporous ones. These characteristics are discussed in the paper taking into account the differences between microstructure and contacts between particles with various form factors. Thus, it is clearly evidenced that the morphology of raw powders and the level of porosity are key parameters to optimize the mechanical properties of such porous material

An Auger and XPS survey of cerium active corrosion protection for AA2024-T3 aluminum alloy

XPS evidenced the proximity of the inhibitor with the surface AA2024 alloy.Cerium conversion coatings with [Ce] = 0.1 M offer the best corrosion resistance. SAM shown the migration of Ce + III entities towards the corrosion pits or crevices. High resolution analyses (Auger) connecting the nano-scale order with the chemical distribution

COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

Epistemology of a Fragmented Archaeology : the Viru-Gallinazo Case, North Coast of Peru

Le terme virú-gallinazo désigne au XXe siècle un style céramique puis caractérise une culture. Aujourd’hui, le consensus archéologique regroupe les vestiges virú-gallinazo sous la dénomination de « phénomène culturel » et cherche ainsi à le définir. Mais l’épistémologie montre l’aspect fragmentaire sur lequel se fondent ces interprétations.Cette thèse propose alors une approche plus complexe du phénomène. Elle se fonde sur les idées suivantes : l’art ne reflète pas l’intégralité des manifestations culturelles. Enfin la signification d’un objet peut varier selon les contextes dans lesquels il se trouve. Ce travail, en conséquence, entreprend une analyse contextuelle croisée des différentes catégories de vestiges.During the XXth century, the viru-gallinazo term first refers to ceramic’s style and after it distinguishes a culture. Today, the archaeological consensus includes the viru-gallinazo remains as a"cultural phenomenon" and seeks to define it. But the epistemology shows the fragmented aspect on which are based those interpretations.This thesis proposes then a more complex approach of the viru-gallinazo "cultural phenomenon". It is based on the following ideas: art does not reflect the entirety of cultural events. Finally the meaning of an object may vary according to the context in which it is located. For that reason, this study sets out a crossed contextual analysis of the different categories of remains

Épistémologie d une archéologie fragmentaire (le cas virú-gallinazo, côte nord du Pérou)

Le terme virú-gallinazo désigne au XXe siècle un style céramique puis caractérise une culture. Aujourd hui, le consensus archéologique regroupe les vestiges virú-gallinazo sous la dénomination de phénomène culturel et cherche ainsi à le définir. Mais l épistémologie montre l aspect fragmentaire sur lequel se fondent ces interprétations.Cette thèse propose alors une approche plus complexe du phénomène. Elle se fonde sur les idées suivantes : l art ne reflète pas l intégralité des manifestations culturelles. Enfin la signification d un objet peut varier selon les contextes dans lesquels il se trouve. Ce travail, en conséquence, entreprend une analyse contextuelle croisée des différentes catégories de vestiges.During the XXth century, the viru-gallinazo term first refers to ceramic s style and after it distinguishes a culture. Today, the archaeological consensus includes the viru-gallinazo remains as a"cultural phenomenon" and seeks to define it. But the epistemology shows the fragmented aspect on which are based those interpretations.This thesis proposes then a more complex approach of the viru-gallinazo "cultural phenomenon". It is based on the following ideas: art does not reflect the entirety of cultural events. Finally the meaning of an object may vary according to the context in which it is located. For that reason, this study sets out a crossed contextual analysis of the different categories of remains.PARIS4-Bib. électronique (751059905) / SudocSudocFranceF

Preparing an archaeological field survey: Remote sensing interpretation for herding structures in the Southern Levant

International audienceDevelopment of archaeological “virtual surveys” using online satellite imagery allows the identification of an increasing number and diversity of data. Coherent procedures are now essential in the preparation of any field study: estimating archaeological potential, gathering and mapping environmental features, and building hypotheses about settlement location and settlement patterns. In this article, we propose methods aimed at developing tools to describe and measure the different elements of pastoral archaeological structures in southern Syria, and quantifying the importance of these structures in the landscape and natural environment. Our thematic case study is the pastoral settlement pattern in the Leja, a basaltic region in southern Syria

Recherche de synergies matières/énergie entre secteurs industriels: Réflexions et perspectives

International audienceIndustrial Ecology is an emerging field, wich gives a systemic approach of the industrial world. Recycling of industrial waste or energy excess by implementing trophic networks is one of its main tasks.Knowledge of the synergies or of the potential connections between the different industry components is a key point to increase the number of those exchanges.This paper, based on survey of for different sectors, attempts to test the interest from a sectorial point of view, and also features the limits of this approach. It then assesses the importance of a mass and energy flow functional description.L’écologie industrielle, domaine scientifique émergent, propose une approche systémique de la société industrielle. Un de ses principaux axes de travail concerne la valorisation systématique des flux de déchets et d’énergie en créant des réseaux d’échange de ces flux.La multiplication des synergies entre les différentes entités du tissu industriel nécessite un développement de la connaissance de ces compatibilités.Cette réflexion, effectuée à partir de l’étude de quatre secteurs industriels et de leurs liens potentiels, propose d’analyser l’intérêt d’aborder la recherche des synergies sous l’angle sectoriel, d’examiner les limites de l’approche, et l’importance de la dimension fonctionnelle des flux de matières et d’énergie

Preparing an archaeological field survey: Remote sensing interpretation for herding structures in the Southern Levant

International audienceDevelopment of archaeological “virtual surveys” using online satellite imagery allows the identification of an increasing number and diversity of data. Coherent procedures are now essential in the preparation of any field study: estimating archaeological potential, gathering and mapping environmental features, and building hypotheses about settlement location and settlement patterns. In this article, we propose methods aimed at developing tools to describe and measure the different elements of pastoral archaeological structures in southern Syria, and quantifying the importance of these structures in the landscape and natural environment. Our thematic case study is the pastoral settlement pattern in the Leja, a basaltic region in southern Syria