pinecone/core-2020-05-10-deduplication huggingface dataset:
Predicting the temperature and reactant concentration profiles of reacting flow in the partial oxidation of hot coke oven gas using detailed chemistry and a one-dimensional flow model

A numerical approach is presented for predicting the species concentrations and temperature profiles of chemically reacting flow in the non-catalytic partial oxidation of hot coke oven gas (HCOG) in a pilot-scale reformer installed on an operating coke oven. A detailed chemical kinetic model consisting of 2216 reactions with 257 species ranging in size from the hydrogen radical to coronene was used to predict the chemistries of HCOG reforming and was coupled with a plug model and one-dimensional (1D) flow with axial diffusion model. The HCOG was a multi-component gas mixture derived from coal dry distillation, and was approximated with more than 40 compounds: H2, CO, CO2, CH4, C2 hydrocarbons, H2O, aromatic hydrocarbons such as benzene and toluene, and polycyclic aromatic hydrocarbons up to coronene. The measured gas temperature profiles were reproduced successfully by solving the energy balance equation accounting for the heat change induced by chemical reactions and heat losses to the surroundings. The approach was evaluated critically by comparing the computed results with experimental data for exit products such as H2, CO, CO2, and CH4, in addition to the total exit gas flow rate. The axial diffusion model slightly improves the predictions of H2, CO, and CO2, but significantly improves those of CH4 and total exit flow rate. The improvements in the model predictions were due primarily to the improved temperature predictions by accounting for axial diffusion in the flow model
The effect of topology on the structure and free energy landscape of DNA kissing complexes

We use a recently developed coarse-grained model for DNA to study kissing complexes formed by hybridization of complementary hairpin loops. The binding of the loops is topologically constrained because their linking number must remain constant. By studying systems with linking numbers −1, 0, or 1 we show that the average number of interstrand base pairs is larger when the topology is more favourable for the right-handed wrapping of strands around each other. The thermodynamic stability of the kissing complex also decreases when the linking number changes from −1 to 0 to 1. The structures of the kissing complexes typically involve two intermolecular helices that coaxially stack with the hairpin stems at a parallel four-way junction
Laue diffraction lenses for astrophysics: Theoretical concepts

Beyond the present technologies, Laue diffraction lenses are very promising tools in the field of gamma-ray astrophysics. The theoretical concepts of this kind of instruments are based on the Laue diffraction in crystals, discovered almost 100 years ago. Though they are commonly used in crystallography, their application to γ-ray focusing in astrophysics requires some specific developments, e.g. in terms of energy and imaging responses. The present article describes the physics of X-ray diffraction in crystals. In the context of the Darwin model of mosaic crystals, some peculiar aspects, relevant to the astrophysical observation, are discussed. The evaluation and optimization of diffraction efficiency are discussed, especially with rigards to the crystal's mosaicity and thickness, its spatial extent and deviations to the “ideally imperfect” Darwin model
From Hard Sphere Dynamics to the Stokes–Fourier Equations: An Analysis of the Boltzmann–Grad Limit

to appear, Annals of PDEsInternational audienceWe derive the linear acoustic and Stokes-Fourier equations as the limiting dynamics of a system of N hard spheres of diameter $\epsilon$ in two space dimensions, when N $\rightarrow$ $\infty$, $\epsilon$ $\rightarrow$ 0, N $\epsilon$ = $\alpha$ $\rightarrow$ $\infty$, using the linearized Boltzmann equation as an intermediate step. Our proof is based on Lanford's strategy [18], and on the pruning procedure developed in [5] to improve the convergence time to all kinetic times with a quantitative control which allows us to reach also hydrodynamic time scales. The main novelty here is that uniform L 2 a pri-ori estimates combined with a subtle symmetry argument provide a weak version of chaos, in the form of a cumulant expansion describing the asymptotic decorrelation between the particles. A refined geometric analysis of recollisions is also required in order to discard the possibility of multiple recollisions
Single and multiple consecutive permutation motif search

International audienceLet t be a permutation (that shall play the role of the text) on [n] and a pattern p be a sequence of m distinct integer(s) of [n], m ≤ n. The pattern p occurs in t in position i if and only if p1 .. . pm is order-isomorphic to ti .. . ti+m 1 , that is, for all 1≤ k ˂ l ≤ m, pk >pl if and only if ti+k -1 > t1+-1 . Searching for a pattern p in a text t consists in identifying all occurrences of p in t. We first present a forward automaton which allows us to search for p in t in O(m2 log log m + n) time. We then introduce a Morris-Pratt automaton representation of the forward automaton which allows us to reduce this complexity to O(m log log m + n) at the price of an additional amortized constant term by integer of the text. Both automata occupy O(m) space. We then extend the problem to search for a set of patterns and exhibit a specific Aho- Corasick like algorithm. Next we present a sub-linear average case search algorithm running in O ( m log m/log log m + n log m /m log log m ) time, that we eventually prove to be optimal on average
A dynamo driven by zonal jets at the upper surface: Applications to giant planets

published in IcarusInternational audienceWe present a dynamo mechanism arising from the presence of barotropically unstable zonal jet currents in a rotating spherical shell. The shear instability of the zonal flow develops in the form of a global Rossby mode, whose azimuthal wavenumber depends on the width of the zonal jets. We obtain self-sustained magnetic fields at magnetic Reynolds numbers greater than 1000. We show that the propagation of the Rossby waves is crucial for dynamo action. The amplitude of the axisymmetric poloidal magnetic field depends on the wavenumber of the Rossby mode, and hence on the width of the zonal jets. We discuss the plausibility of this dynamo mechanism for generating the magnetic field of the giant planets. Our results suggest a possible link between the topology of the magnetic field and the profile of the zonal winds observed at the surface of the giant planets. For narrow Jupiter-like jets, the poloidal magnetic field is dominated by an axial dipole whereas for wide Neptune-like jets, the axisymmetric poloidal field is weak
Geophysical investigation of a large landslide in glaciolacustrine clays in the Trièves area (French Alps)

International audienceSlope movements in clay deposits are spread all over the world and result from complex deformation processes, including internal strains in the landslide body and slipping along rupture surfaces. Such mass movements are likely to generate changes in the geophysical parameters characterizing the ground, which can be used to map the landslide body. In the last decade, geophysical techniques have been increasingly used for landslide investigation purposes. However, the success of any geophysical technique is overall controlled by the existence of a geophysical contrast differentiating the body to be mapped. For landslides affecting thick clay materials (from soft clay to shale or marl), electrical and seismic techniques have been mainly applied in the past. In this study, we attempt to physically characterize the deformation within a large slide (Avignonet) affecting laminated clays which were deposited in a glacially dammed lake during the Würm period. Clay deposits, which cover an area of 300 km2 south of Grenoble (French Alps) and have a maximum thickness of 200 m, overlay compact alluvial layers and marly limestone of Mesozoic age. Piezometric data at Avignonet show that the water table is very shallow, implying that the slide developed in saturated clay. Several seismic and electrical proﬁles were performed in order to tentatively correlate the variations of P-wave (Vp) velocity, S-wave velocity (Vs) and electrical resistivity with geotechnical data and morphological observations. In such saturated and ﬁne material, it turned out that only the S-wave velocity exhibits signiﬁcant variations with the displacement rates and the morphological features. Vs values at shallow depth were found to be inversely correlated with displacement rates measured by GPS, with a division by at least a factor of 2 between the zones unaffected and strongly deformed by the landslide. These results suggest that Vs mapping could provide valuable information on the deformation state of the clay material and that the evolution of Vs with time could be used as an indicator for characterizing the landslide activity in the subsurface, including the evolution into a ﬂow
The " Mendelian Gene " and the " Molecular Gene " : Two Relevant Concepts of Genetic Units

International audienceWe focus here on two prevalent meanings of the word gene in research articles. On one hand, the gene, named here “molecular gene”, is a stretch of DNA that is transcribed and codes for an RNA or a polypeptide with a known or presumed function (as in “gene network'), whose exact spatial delimitation on the chromosome remains a matter of debate, especially in cases with alternative splicing, antisense transcripts, etc. On the other hand, the gene, called here “Mendelian gene”, is a segregating genetic unit which is detected through phenotypic differences associated with different alleles at the same locus (as in “gene flow”). We show that the “Mendelian gene” concept is still extensively used today in biology research and is sometimes confused with the “molecular gene”. We try here to clarify the distinction between both concepts. Efforts to delineate the beginning and the end of the DNA sequence corresponding to the “Mendelian gene” and the “molecular gene” reveal that both entities do not always match. We argue that both concepts are part of two relevant frameworks for explaining the biological world
From urban concept to urban engineering: The contribution of distributed collaborative design to the management of urban projects

International audienceThe complexity of urban systems is an increasingly common topic in academic literature. Following in the footsteps of the industrial sector, which has understood this issue for many years, urban engineering must also tackle the challenges created by complex systems. Industrial engineering has provided a number of responses to this challenge, including design technologies, which are notably collaborative. It seems possible, at least in theory, to transfer a number of best practice methods and adapt these to the conceptualization of urban development projects (in the initial phase) in order to encourage their global management (in terms of strategic decision making) and their social acceptability. The challenge is then to formulate new methodological models, as well as to create an environment dedicated to their application
Ornaments from the Magdalenian burial area in El Mirón Cave (Cantabria, northern Spain). Were they grave goods?

International audienceEl Mirón Cave, located in northern Atlantic Iberia, has produced important evidence of human occupation during the Lower Magdalenian (19-17.5 cal kya). Among the finds dating to this period is that of a disturbed primary burial of an adult woman. The excavation of the small area around the burial yielded a considerable number of ornamental items (mainly shell beads), but the actual association of any of them with the interment is problematic. The results of our study of the perforated marine shells and mammal teeth suggest that the ornamental objects were not grave goods, but rather were simply artifacts present in the occupation layers in this part of the cave. The materials used to make ornaments were gathered by collecting shells along the Late Glacial shore and by hunting ungulates. The perforation techniques used were similar to those found at contemporary sites in the Franco-Cantabrian region and the appearance of various elements from the manufacturing operatory chain indicates that some of the ornaments were made at the site. It was also possible to determine that some of the shells were used—probably suspended or attached to other objects. From a functional standpoint, the ornaments probably played not only an aesthetic role, but also a symbolic one, facilitating communication and exchanges among human groups
Late Pleistocene to Holocene palaeoenvironmental variability in the north-west Spanish mountains: insights from a source-to-sink environmental magnetic study of Lake Sanabria

International audienceWe present a source-to-sink environmental magnetic study of a sediment core from Lake Sanabria (north-west Iberian Peninsula) and rocks of its catchment. The results indicate the occurrence of magnetite, and probably also pyrrhotite, in sediments accumulated between ca. 26 and 13 cal ka BP in a proglacial lake environment. These minerals also appear to dominate the magnetic assemblage of Palaeozoic rocks from the lake catchment. This indicates that sedimentation was then driven by the erosion of glacial flour, which suffered minimal chemical transformation due to a rapid and short routing to the lake. A sharp change in magnetic properties observed in the lake sediments between 13 and 12.6 cal ka BP reflects the rapid retreat of glaciers from the lake catchment. Sediments from the upper half of the studied sequence, accumulated after 12.6 cal ka BP in a lacustrine environment with strong fluvial influence, contain magnetite and smaller amounts of maghemite and greigite. We suggest that greigite grew authigenically under anoxic conditions caused by enhanced accumulation of organic matter into the lake. The occurrence of maghemite in these sediments suggests pedogenic activity in the then deglaciated lake catchment before the erosion and transportation of detrital material into the lake
On the evolution of the viscoelastic properties and its microstructural/chemical origin in filled NBR subjected to coupled thermal and mechanical loads

This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/authorsrightsInternational audienceThis study deals with the effect of coupled thermal and cyclic mechanical loadings on the viscoelastic response of carbon black filled nitrile rubber. For this purpose, cyclic loading tests were performed at different temperatures by means of Dynamic Mechanical and Thermal Analysis (DMTA). The type and level of the thermomechanical loadings applied were chosen in order to determine the relative contribution of each of the mechanical and thermal loadings (and their coupling) to the viscoelastic response during the cyclic tests. X-ray Photoelectron Spectroscopy (XPS) and Fourier Transformed Infrared spec-troscopy (FTIR) analyses were also carried out to track the change in the chemical structure corresponding to the evolution in the viscoelastic response. First, results obtained show that due to the crosslink increase, the storage modulus increases with the number of cycles. It is also observed that temperature amplifies this phenomenon. Second, the cyclic mechanical loading is found to significantly amplify the effect of temperature
Biological activity of a SiO2-CaO-P2O5 sol-gel glass highlighted by PIXE-RBS methods

presented at CAARI 2006:19th International Conference on the Application of Accelerators in Research and Industry, Forth Worth, Etats Unis, 20-25 Aug 2006, 11 pp, 4 figures, submitted to NIMB - PNAB, présenté par J. Lao, à paraître dans NIMBInternational audienceIt is proposed in this study to observe the influence of P2O5 on the formation of the apatite-like layer in a bioactive glass via a complete PIXE characterization. A glass in the SiO2-CaO-P2O5 ternary system was elaborated by sol-gel processing. Glass samples were soaked in biological fluids for periods up to 10 days. The surface changes were characterized using Particle Induced X-ray Emission (PIXE) associated to Rutherford Backscattering Spectroscopy (RBS), which are efficient methods for multielemental analysis. Elemental maps of major and trace elements were obtained at a micrometer scale and revealed the bone bonding ability of the material. The formation of a calcium phosphate-rich layer containing magnesium occurs after a few days of interaction. We demonstrate that the presence of phosphorus in the material has an impact on the development and the formation rate of the bone-like apatite layer. Indeed, the Ca/P atomic ratio at the glass/biological fluids interface is closer to the nominal value of pure apatite compared to P2O5 free glasses. It would permit, in vivo, an improved chemical bond between the biomaterials and bone
Capacity and interference modeling of CSMA/CA networks using SSI point processes

International audienceThe relative location of simultaneous transmitters, i.e. the set of nodes transmitting a frame at a given time, has a crucial impact on the performance of multi hop wireless networks. Two fundamental aspects of wireless network performances are related to these locations: capacity and interference. Indeed, as interference results from the summation of signals stemmed by concurrent transmitters, it directly depends on the transmitters' location. On the other hand, the network capacity is proportional to the number of simultaneous transmitters. In this paper, we investigate original point processes that can be used to model the location of transmitters that comply with the CSMA/CA policies, i.e. the Medium Access Control protocol used in 802.15.4 and 802.11 families of wireless technologies. We first propose the use of the Simple Sequential Inhibition point process to model CSMA/CA networks where clear channel assessment depends on the strongest emitter only. We then extend this point process to model a busy medium detection based on the strength of all concurrent signals. We finally compare the network capacity obtained through realistic simulations to a theoretical capacity estimated using the intensity of the SSI point process. It turns out that the proposed model is validated by the simulations
A women’s boom in the boardroom: effects on performance?

International audienceThis article analyzes whether improving gender diversity in boardrooms improves firms' economic performance. In the context of French CAC40-listed companies between 2008 and 2012, this research uses instrumental variable panel regressions, including production frontier estimates, to arrive at two key results. First, gender diversity in boards depends on firms' attributes, including their previous gender promotion strategies. Second, promoting women in boardrooms has a significant and positive effect on economic performance, after accounting for the endogeneity of diversity. Gender diversity even reduces corporate inefficiencies and enables firms to come closer to their optimal performance
Semi-automated stereoradiographic upper limb 3D reconstructions using a combined parametric and statistical model: a preliminary study

PURPOSE: Quantitative assessment of 3D clinical indices may be crucial for elbow surgery planning. 3D parametric modeling from bi-planar radiographs was successfully proposed for spine and lower limb clinical investigation as an alternative for CT-scan. The aim of this study was to adapt this method to the upper limb with a preliminary validation. METHODS: CT-scan 3D models of humerus, radius and ulna were obtained from 20 cadaveric upper limbs and yielded parametric models made of geometric primitives. Primitives were defined by descriptor parameters (diameters, angles...) and correlations between these descriptors were found. Using these correlations, a semi-automated reconstruction method of humerus using bi-planar radiographs was achieved: a 3D personalized parametric model was built, from which clinical parameters were computed [orientation and projections on bone surface of trochlea sulcus to capitulum (CTS) axis, trochlea sulcus anterior offset and width of distal humeral epiphysis]. This method was evaluated by accuracy compared to CT-scan and reproducibility. RESULTS: Points-to-surface mean distance was 0.9 mm (2 RMS = 2.5 mm). For clinical parameters, mean differences were 0.4-1.9 mm and from 1.7° to 2.3°. All parameters except from angle formed by CTS axis and bi-epicondylar axis in transverse plane were reproducible. Reconstruction time was about 5 min. CONCLUSIONS: The presented method provides access to morphological upper limb parameters with very low level of radiation. Preliminary in vitro validation for humerus showed that it is fast and accurate enough to be used in clinical daily practice as an alternative to CT-scan for total elbow arthroplasty pre operative evaluation
Filtering the Wright-Fisher diffusion

International audienceWe consider a Wright-Fisher diffusion (x(t)) whose current state cannot be observed directly. Instead, at times t1 < t2 < ..., the observations y(ti) are such that, given the process (x(t)), the random variables (y(ti)) are independent and the conditional distribution of y(ti) only depends on x(ti). When this conditional distribution has a specific form, we prove that the model ((x(ti),y(ti)), i$\ge$1) is a computable filter in the sense that all distributions involved in filtering, prediction and smoothing are exactly computable. These distributions are expressed as finite mixtures of parametric distributions. Thus, the number of statistics to compute at each iteration is finite, but this number may vary along iterations
Self-regulation of turbulence bursts and transport barriers

International audienceThe interplay between turbulent bursts and transport barriers is analyzed with a simplified model of interchange turbulence in the Scrape-Off Layer of magnetically confined plasmas. The turbulent bursts spread into the transport barriers, and, depending on the competing magnitude of the burst and stopping capability of the barrier can burn through. Two models of transport barriers are presented, a hard barrier where all turbulent modes are stable in a prescribed region and a soft barrier with external plasma biasing. This process can be modeled on the basis of competing stochastic processes. For classes of probability density function of these processes one can predict the heavy tail properties of the bursts downstream from the barrier, either exponential for a leaky barrier, or with power laws, for a tight barrier. The intrinsic probing of the transport barriers by the turbulent bursts thus gives access to properties of the transport barriers. The main stochastic variables of the two models addressed here are the barrier width and the spreading distance of the turbulent bursts within the barrier together with their level of correlation. One finds that in the case of a barrier located in the Scrape-Off-Layer, the stochastic model predicts a leaky barrier with an exponential probability density function of escaping turbulent bursts in agreement with the simulation data