pinecone/core-2020-05-10-deduplication huggingface dataset:
Scale effects on the response of composite structures under impact loading

For several years, composite materials have taken a significant part in the realization of structures designed for transport (aeronautical, nautical, automotive. . .). In order to qualify the behavior of such structures, preliminary validation tests have to be done. These specific tests are often very expensive and difficult to set up, especially when the structure dimensions are large (fuselages of aircraft, ship hulls. . .). An alternative way is then to employ small-scale models.
The use of these reduced scale structures requires the identification of similitude models allowing the extrapolation of the small-scale model behavior to the real structure. Although largely developed in the case of homogeneous materials, such similitude techniques are not clearly identified for composite materials taking into account the damage evolution during
an impact.
The purpose of this article is firstly to present existing similitude techniques making it possible to predict the composite structure behaviour from the knowledge of small-scale model response. Secondly, experiments were done on two scale of samples carried out by stratification of unidirectional carbon/epoxy plies. These results were finally compared with the
analytical predictions of similitude laws currently used.
The aim of this paper is to contribute to similitude laws development applied to composite structures. These laws permit to extrapolate the small-scale model behavior to the real scale one. Existing approaches have been established following
two different methods. They are summarized in this paper and applied to impact loadings on two laminated plate scales.
In order to complete data collected by ‘‘conventional’’ instrumentation (force transducer, displacement sensor, accelerometer.. .), optical device such as an high-velocity CCD camera, associated with optical techniques for the monitoring of markers, were used. These techniques make possible to compare displacement lines corresponding to each scale. It is shown that existing similitude laws, used for elastic materials, do not allow to simulate the behavior of the real scale when this one is damaged
Transient growth in the flow past a three-dimensional smooth roughness element

This work provides a global optimization analysis, looking for perturbations inducing the largest energy growth at a finite time in a boundary-layer flow in the presence of smooth three-dimensional roughness elements. Amplification mechanisms are described which can bypass the asymptotical growth of Tollmien–Schlichting waves. Smooth axisymmetric roughness elements of different height have been studied, at different Reynolds numbers. The results show that even very small roughness elements, inducing only a weak deformation of the base flow, can localize the optimal disturbance  characterizing the Blasius boundary-layer flow. Moreover, for large enough
bump heights and Reynolds numbers, a strong amplification mechanism has been recovered, inducing an increase of several orders of magnitude of the energy gain with respect to the Blasius case. In particular, the highest value of the energy gain is obtained for an initial varicose perturbation, differently to what found for a  streaky parallel flow. Optimal varicose perturbations grow very rapidly by transporting the strong wall-normal shear of the base flow, which is localized in the wake of the bump. Such optimal disturbances are found to lead to transition for initial energies and amplitudes considerably smaller than sinuous optimal ones, inducing hairpin vortices downstream of the roughness element
The Kramer sampling theorem revisited

The classical Kramer sampling theorem provides a method for obtaining orthogonal sampling formulas. Besides, it has been the cornerstone for a significant mathematical literature on the topic of sampling theorems associated with differential and difference problems. In this work we provide, in an unified way, new and old generalizations of this result corresponding to various different settings; all these generalizations are illustrated with examples. All the different situations along the paper share a basic approach: the functions to be sampled are obtaining by duality in a separable Hilbert space H through an H -valued kernel K defined on an appropriate domain
A new device for combined Coulomb excitation and isomeric conversion electron spectroscopy with fast fragmentation beams

LISE3, SISSIA new setup has been designed to perform Coulomb excitation experiments with fragmentation beams at intermediate energy and to measure at the same time conversion electrons from isomeric states populated in the fragmentation reaction. The newly designed setup is described and experimental results from a first experiment are shown. Radioactive even-even nuclei in the mass region A ≃ 70 close to the N = Z line were Coulomb excited after fragmentation of an intense primary $^{78}$Kr beam and selection in flight with the LISE3 spectrometer at GANIL. The rays emitted after Coulomb excitation were detected in an array of four large segmented HPGe clover detectors in a very close geometry. The scattered ions were identified in a stack of highly segmented annular silicon detectors combined with a time-of-flight measurement using beam tracking detectors. Conversion electrons from isomeric $0^+_2$ states decaying via electric monopole transitions were detected in an array of segmented cooled silicon detectors surrounding a telescope of plastic scintillators. Reduced transitions probabilities B(E2; $0^+_1$ → $2^+_1$ ) were deduced for several stable and radioactive nuclei
Exclusive measurements on $^{56}$Fe+p at 1 A Gev with the SPALADIN setup at GSI

A new type of spallation experiments has been carried out at GSI, Darmstadt (Germany) in order to understand the spallation mechanism in greater details. These experiments use the inverse-kinematics technique where the ion beam is directed onto a liquid Hydrogen target, allowing the detection of heavy spallation residues in coincidence with low center-of-mass energy light particles. The setup is based on A Large Acceptance DIpole magNet (ALADIN) coupled with a multitrack Time Projection Chamber (TPC), a hodoscope and a neutron detector. First, data on $^{56}$Fe+p at 1 A GeV were taken in February 2004. In the on-going analysis, isotopic cross-sections have been determined and compared to data taken at the FRagment Separator in GSI. Mean values and width of residue velocity distributions have also been obtained as well as Helium production cross-section. First, coincidence data are being analyzed
Geant4 simulation of the response of phosphor screens for X-ray imaging

poster Pistrui-Maximean, submitted to NIM AIn order to predict and optimize the response of phosphor screens, it is important to understand the role played by the different physical processes inside the scintillator layer. Monte Carlo simulations were carried out to determine the Modulation Transfer Function (MTF) of phosphor screens for energies used in X-ray medical imaging and nondestructive testing applications. The visualization of the dose distribution inside the phosphor layer gives an insight into how the MTF is progressively degraded by X-ray and electron transport. The simulation model allows to study the inﬂuence of physical and technological parameters on the detector performances, as well as to design and optimize new detector conﬁgurations. Preliminary MTF measurements have been carried out and agreement with experimental data has been found in the case of a commercial screen (Kodak Lanex Fine), at an X-ray tube potential voltage of 100 kV. Further validation with other screens (transparent or granular) at different energies is under way
Asymptomatic Giardia Intestinalis infection and Roux-Y-Gastric Bypass

International audienceGiardiasis is one of the most common parasitic infections of the human intestine worldwide, and ranges from 3-7% in western countries to 100% in some populations [1]. Giardia Intestinalis (i.e Duodenalis or Lamblia) is a flagellated, binucleated protozoan parasite that infects the upper intestinal tract in many mammalian hosts. Giardiasis can present with a broad range of clinical manifestations, from being asymptomatic to acute or chronic nonspecific gastro-intestinal symptoms associated with malnutrition [2]. However little is known regarding Giardiasis in human obesity. [...
The Mean-Field Limit for a Regularized Vlasov-Maxwell Dynamics

34 pages; some typos have been fixedInternational audienceThe present work establishes the mean-field limit of a N-particle system towards a regularized variant of the relativistic Vlasov-Maxwell system, following the work of Braun-Hepp [Comm. in Math. Phys. 56 (1977), 101--113] and Dobrushin [Func. Anal. Appl. 13 (1979), 115--123] for the Vlasov-Poisson system. The main ingredients in the analysis of this system are (a) a kinetic formulation of the Maxwell equations in terms of a distribution of electromagnetic potential in the momentum variable, (b) a regularization procedure for which an analogue of the total energy --- i.e. the kinetic energy of the particles plus the energy of the electromagnetic field --- is conserved and (c) an analogue of Dobrushin's stability estimate for the Monge-Kantorovich-Rubinstein distance between two solutions of the regularized Vlasov-Poisson dynamics adapted to retarded potentials
Heat transfers in a double-skin roof ventilated by natural convection in summer time

International audienceThe double-skin roofs investigated in this paper are formed by adding a metallic screen on an existing sheet metal roof. The system enhances passive cooling of dwellings and can help diminishing power costs for air conditioning in summer or in tropical and arid countries. In this work, radiation, convection and conduction heat transfers are investigated. Depending on its surface properties, the screen reflects a large amount of oncoming solar radiation. Natural convection in the channel underneath drives off the residual heat. The bi-dimensional numerical simulation of the heat transfers through the double skin reveals the most important parameters for the system's efficiency. They are, by order of importance, the sheet metal surface emissivity, the screen internal and external surface emissivity, the insulation thickness and the inclination angle for a channel width over 6 cm. The influence of those parameters on Rayleigh and Nusselt numbers is also investigated. Temperature and air velocity profiles on several channel cross-sections are plotted and discussed
Gas-solid carbonation of Ca(OH)2 and CaO particles under non-isothermal and isothermal conditions by using a thermogravimetric analyzer: Implications for CO2 capture

International audienceThe gas-solid carbonation of alkaline sorbents has been actively investigated as an alternative method to CO2 capture from industrial combustion sources and CO2 contained in the air. This study has a two-fold objective: firstly, quantify the gas-solid carbonation extent and the carbonation kinetics of Ca(OH)2 and CaO; and secondly, propose a reaction mechanism of gas-solid carbonation for CaO under dry conditions (relative humidity close to 0), i.e., when the action of water is negligible. The main results of our study have revealed that a high proportion of Ca(OH)2 nanoparticles were transformed into CaCO3 particles by gas-solid carbonation (carbonation extent, >0.94) under non-isothermal conditions. Moreover, this gas-solid reaction requires low activation energy (Ea≈6kJ/mol) at a constant heating rate of 5 or 10K/min. A similar carbonation extent was determined for gas-solid carbonation of in-situ synthesized CaO under non-isothermal conditions. However, the gas-solid carbonation of CaO takes place in a broader temperature range, implying a more complex thermokinetic behavior (overlapping of carbonation regimes or steps). Concerning the gas-solid carbonation of Ca(OH)2 and CaO under isothermal conditions, a high carbonation extent (>0.9) was determined for CaO at 600 (873K) and 800°C (1073K). Conversely, the gas-solid carbonation of Ca(OH)2 particles was relatively low (<0.56) at 400°C (673K) after 6h of reaction. This case is in agreement with the formation of a dense non-porous layer of carbonate mineral around the core of the reacting Ca(OH)2 particles, thereby limiting the transfer of CO2. Finally, an alternative reaction mechanism is proposed for the gas-solid carbonation of CaO, when the relative humidity is close to 0. This macroscopic control at high temperature avoids CO2 dissociation with molecular water at the CaO-CO2 interface. For these specific conditions, the mineralization of adsorbed CO2 on CaO particles implies a solid state transformation, i.e., CaCO3 formation from CaO-CO2 interactions. This could be explained by an atomic excitation than at high temperature allows the local migration of one oxygen atom from the solid towards the adsorbed CO2 leading to its mineralization into carbonate (porous or non-porous layer) around the reacting particles; chemically the mineralization of CO2 also implies the breaking of one covalent bond in the CO2 molecule
Designing Project Management for Global Software Development

Part 2: Creating Value through Software DevelopmentInternational audienceSoftware development in distributed teams remains challenging despite rapid technical improvement in tools for communication and collaboration across distance. The challenges stem from geographical, temporal and sociocultural distance and manifest themselves in a variety of difficulties in the development projects. This study has identified a range of difficulties described in the literature of global software development, lacking sufficient solutions. In particular, advice for project managers is lacking. Design science research has been applied to design a model to guide project managers of distributed software teams, based on a practice study and informed by well-known theories. Our work pinpoints the difficulties of handling the vital informal processes in distributed collaboration that are so vulnerable because the distances risk detaining their growth and increasing their decay rate. The research suggest to support and securing these informal processes through explicit and formal means and to ensure management’s continuous focus on this effort to succeed
A New Method to Characterize Density Adapted to a Coarse City Model

International audienceDensity is probably one of the most used indicators to characterize urban development. Even if it is a quantitative and properly defined measure, there are still problems to use it properly. This paper proposes a renewed approach to characterize urban density based on buildings' footprints. It can be applied on huge datasets and allows multi-level characterization of density. We first present an original partition of urban open space. This topology helps us to define a neighborhood function. We then adapt the GSI and FSI indices to the previously defined tessellation. The combination of the neighborhood function and the modified indices makes it possible to assess density iteratively. For each building, these values allow to define density profile which is then used in a classification process. The results highlight spatial patterns and homogeneous areas. This transposable method is adapted to urban fabric characterization and surpasses old descriptive and low formalized classifications
Astrocladistics: a phylogenetic analysis of galaxy evolution I. Character evolutions and galaxy histories

16 pages, 6 figuresThis series of papers is intended to present astrocladistics in some detail and evaluate this methodology in reconstructing phylogenies of galaxies. Being based on the evolution of all the characters describing galaxies, it is an objective way of understanding galaxy diversity through evolutionary relationships. In this first paper, we present the basic steps of a cladistic analysis and show both theoretically and practically that it can be applied to galaxies. For illustration, we use a sample of 50 simulated galaxies taken from the GALICS database, which are described by 91 observables (dynamics, masses and luminosities). These 50 simulated galaxies are indeed 10 different galaxies taken at 5 cosmological epochs, and they are free of merger events. The astrocladistic analysis easily reconstructs the true chronology of evolution relationships within this sample. It also demonstrates that burst characters are not relevant for galaxy evolution as a whole. A companion paper is devoted to the formalization of the concepts of formation and diversification in galaxy evolution
Group Emotions in Collective Reasoning: a Model

International audienceEducation and cognition research today generally recognize the tri-dimensional nature of reasoning processes as involving cognitive, social and emotional phenomena. However, there is so far no theoretical framework articulating these three dimensions from a descriptive perspective. This paper aims at presenting a first model of how group emotions work in collective reasoning, and specifies their social and cognitive functions. This model is inspired both from a multidisciplinary literature review and our extensive previous empirical work on an international corpus of videotaped student debates. The cognitive function of emotions is defined in reference to the process of schematization (Grize 1996, 1997) and associated emotional framing (Polo et al. 2013). On the other hand, the social function of emotions refers to recognition-oriented behaviors that correspond to engagement into specific types of group talk (e.g. Mercer 1996), implying specific politeness rules or face-preservation systems (Brown and Levinson 1988). We believe that our multi-dimensional and multi-level approach to group reasoning, which mostly employs a linguistic perspective, can be applied to a diversity of contexts. We hope it will serve as a basis for further discussion on the role of emotions in reasoning among the interdisciplinary community of argumentation studies
Fair Intergenerational Sharing of a Natural Resource

International audienceIn this article, overlapping generations are extracting a natural resource over an inﬁnite future. We examine the fair allocation of resource and compensations among generations. Fairness is deﬁned by core lower bounds and aspiration upper bounds. The core lower bounds require that every coalition of generations obtains at least what it could achieve by itself. The aspiration upper bounds require that no coalition of generations enjoys a higher welfare than it would achieve if nobody else extracted the resource. We show that, upon existence, the allocation that satisﬁes the two fairness criteria is unique and assigns to each generation its marginal contribution to the preceding generation. Finally, we describe the dynamics of such an allocation
Continuous Mobility Surveys: The State of Practice

International audienceIn this paper we challenge the prevailing practice of conducting one-off cross-sectional mobility surveys, making a case for change on the basis of usefulness and cost-effectiveness. We believe that urban areas over say, one million inhabitants, should collect mobility data on a continuous basis as part of their efforts to guarantee sustainable development. This would allow them to gain a proper understanding of the pressing environmental and transport-related issues of today's world, as well as of the effects of economic growth and price (especially for fuel) volatility. In our scope we include panel data (i.e. information from a smaller sample of respondents who are interviewed at different points in time, hopefully during several years), as this type of information is unique in its ability to help understanding behavioural changes and the impact of time-related effects, such as habit and inertia. We revise the state of affairs in different parts of the world, not limiting ourselves to urban data. Continuous surveys, on-going surveys, panel surveys
Understanding the biokinetics of ibuprofen after single and repeated treatments in rat and human in vitro liver cell systems.

International audienceCommon in vitro toxicity testing often neglects the fate and intracellular concentration of tested compounds, potentially limiting the predictability of in vitro results for in vivo extrapolation. We used in vitro long-term cultures of primary rat (PRH) and human hepatocytes (PHH) and HepaRG cells to characterise and model the biokinetic profile of ibuprofen (IBU) after single and daily repeated exposure (14 days) to two concentrations. A cross-model comparison was carried out at 100μM, roughly corresponding to the human therapeutic plasma concentration. Our results showed that IBU uptake was rapid and a dynamic equilibrium was reached within 1 or 2 days. All three cell systems efficiently metabolised IBU. In terms of species-differences, our data mirrored known in vivo results. Although no bioaccumulation was observed, IBU intracellular concentration was higher in PRH due to a 10-fold lower metabolic clearance compared to the human-derived cells. In HepaRG cells, IBU metabolism increased over time, but was not related to the treatment. In PHH, a low CYP2C9 activity, the major IBU-metabolising CYP, led to an increased cytotoxicity. A high inter-individual variability was seen in PHH, whereas HepaRG cells and PRH were more reproducible models. Although the concentrations of IBU in PRH over time differed from the concentrations found in human cells under similar exposure conditions
Selectivity of natural, synthetic and environmental estrogens for zebrafish estrogen receptors.

International audience: Zebrafish, Danio rerio, is increasingly used as an animal model to study the effects of pharmaceuticals and environmental estrogens. As most of these estrogens have only been tested on human estrogen receptors (ERs), it is necessary to measure their effects on zebrafish ERs. In humans there are two distinct nuclear ERs (hERα and hERβ), whereas the zebrafish genome encodes three ERs, zfERα and two zfERβs (zfERβ1 and zfERβ2). In this study, we established HeLa-based reporter cell lines stably expressing each of the three zfERs. We first reported that estrogens more efficiently activate the zfERs at 28°C as compared to 37°C, thus reflecting the physiological temperature of zebrafish in wildlife. We then showed significant differences in the ability of agonist and antagonist estrogens to modulate activation of the three zfER isotypes in comparison to hERs. Environmental compounds (bisphenol A, alkylphenols, mycoestrogens) which are hER panagonists and hERβ selective agonists displayed greater potency for zfERα as compared to zfERβs. Among hERα selective synthetic agonists, PPT did not activate zfERα while 16α-LE2 was the most zfERα selective compound. Altogether, these results confirm that all hER ligands control in a similar manner the transcriptional activity of zfERs although significant differences in selectivity were observed among subtypes. The zfER subtype selective ligands that we identified thus represent new valuable tools to dissect the physiological roles of the different zfERs. Finally, our work also points out that care has to be taken in transposing the results obtained using the zebrafish as a model for human physiopathology