Tectonic control on southern Sierra Nevada topography, California

In this study we integrate the apatite (U-Th)/He thermochronometric technique with geomorphic, structural, and stratigraphic studies to pursue the origin and evolution of topographic relief related to extensive late Cenozoic faulting in the southern Sierra Nevada. The geomorphology of this region reflects a transition from a vast region to the north characterized by nonequilibrium fluvial modification of a relict low-relief landscape, little affected by internal deformation, to a more complex landscape affected by numerous faults. Regionally, the relict landscape surface is readily resolved by age-elevation relationships of apatite He ages coupled to geomorphology. These relationships can be extended into the study area and used as a structural datum for the resolution of fault offsets and related tilting. On the basis of 63 new apatite He ages and stratigraphic data from proximal parts of the San Joaquin basin we resolve two sets of normal faults oriented approximately N–S and approximately NW. Quaternary west-side-up normal faulting along the N–S Breckenridge–Kern Canyon zone has resulted in a southwest step over from the Owens Valley system in the controlling structure on the regional west tilt of Sierran basement. This zone has also served as a transfer structure partitioning Neogene-Quaternary extension resulting from normal displacements on the NW fault set. This fault system for the most part nucleated along Late Cretaceous structures with late Cenozoic remobilization representing passive extension by oblate flattening as the region rose and stretched in response to the passage of a slab window and the ensuing delamination of the mantle lithosphere from beneath the region

Propagative Deployment of Hierarchical Components in a Dynamic Network

International audienceThis paper addresses the distribution and the deployment of hierarchical components on heterogeneous dynamic networks. Such networks may include fixed and mobile resource-constrained devices and are characterized by the volatility of their hosts and connections, which may lead to their fragmentation. We propose a propagative, hierarchically-controlled deployment process for such networks and an ADL extension allowing the specification of this context-aware deployment

Performance Evaluation of Automatically Generated Data Parallel Programs

International audienceIn this paper, the problem of evaluating the performance of parallel programs generated by data parallel compilers is studied. These compilers take as input an application written in a sequential language augmented with data distribution directives and produce a parallel version based on the specifed partitioning of data. A methodology for evaluating the relationships existing among the program characteristics, the data distribution adopted, and the performance indices measured during the program execution is described. It consists of three phases: a "static" description of the program under study, a "dynamic" description, based on the measurement and the analysis of its execution on a real system, and the construction of a workload model, by using workload characterization techniques. Following such a methodology, decisions related to the selection of the data distribution to be adopted can be facilitated. The approach is exposed through the use of the Pandore environment, designed for the execution of sequential programs on distributed memory parallel computers. It is composed of a compiler, a runtime system and tools for trace and profile generation. The results of an experiment explaining the methodology are presented

Solving the Integrated Bin Allocation and Collection Routing Problem for Municipal Solid Waste: a Benders Decomposition Approach

The municipal solid waste system is a complex reverse logistic chain which comprises several optimisation problems. Although these problems are interdependent, i.e., the solution to one of the problems restricts the solution to the other, they are usually solved sequentially in the related literature because each is usually a computationally complex problem. We address two of the tactical planning problems in this chain by means of a Benders decomposition approach: determining the location and/or capacity of garbage accumulation points, and the design and schedule of collection routes for vehicles. Our approach manages to solve medium-sized real-world instances in the city of Bah\'{i}a Blanca, Argentina, showing smaller computing times than solving a full MIP model.Comment: 29 pages, 6 figure

Comportement à l'impact transversal d'un contreplaqué de bouleau en dynamique et à température cryogénique

Dans le transport par voix maritime du gaz liquide à la température cryogénique de -163°C, le dispositif Mark-III met en œuvre un sandwich isolant contreplaqué-mousse fibrée-contreplaqué recouvert d’un peau d’étanchéité en inox 304L (1.2mm) appelé complexe. Le phénomène de sloshing [KIM] peut entraîner l’arrachage de pièces métalliques fixées à un mât support vertical traversant la cuve. Notre objectif est d’étudier la réponse à l’impact par ces pièces du complexe isolant. Les lois de comportement de l’inox et de la mousse polyuréthane sont supposées connues. Souhaitant simuler numériquement l’impact du complexe par un projectile, on souhaite déterminer les caractéristiques mécaniques transversales du contre plaqué en conditions cryogéniques dynamiques, en utilisant par exemple une loi de type Modified_Crushable_Foam avec le logiciel LS_Dyna. Ce contre plaqué de 12mm d’épaisseur est constitué de fibres de bouleau. Il est constitué de 9 plis croisés à 90°. Des essais de compression transversale sont réalisés en quasistatique et dynamique, sur des barres de Hopkinson, pour atteindre des vitesses de déformations jusqu’à 1000s-1 afin de connaître l’influence de la vitesse de déformation [REID] sur le comportement mécanique. Compte tenu des températures d’utilisation du matériau, ces essais seront réalisés à températures ambiante et cryogénique. Des essais d’impact sur le complexe sont également réalisés à températures ambiante et cryogénique. Les conditions aux limites sont du type encastrement sur la périphérie du complexe et simplement supporté sur sa face inférieure. Les extrémités du projectile seront diédrique, triédrique ou circulaire. Les énergies mises en jeu permettent la perforation de la tôle d’inox sans rupture globale du contreplaqué. Pour valider le choix des paramètres matériaux du contreplaqué, les simulations numériques de ces essais d’impact sont confrontés aux résultats expérimentaux. [KIM] Fatigue strength assessment of MARK-III type LNG cargo containment system, Myung HyunKim , SangMinLee , JaeMyungLee , ByungJaeNoh , WhaSooKim : Ocean Engineering, 37 (2010) 1243–1252 [REID] Dynamic uniaxial crushing of wood, Reid S.R., PENG C. : Int. J. Impact Engng, Vol. 19, (1997), N°. 5-6, 531-57

Binswanger, la réponse de l’amour

L’absence de l’amour dans Être et temps a souvent été remarquée. Qu’il s’agisse ou non d’une lacune dans l’analytique existentiale, cette absence est bien ce qui a motivé Ludwig Binswanger à proposer en 1942, dans les Grundformen und Erkenntnis menschlichen Daseins (Formes fondamentales et connaissance du Dasein humain), une description phénoménologique de l’amour qui s’appuie directement sur les structures existentiales du Dasein telles que les a dégagées Heidegger. Ce faisant, l’ambition de..

Les acteurs français de l’adoption internationale au risque de l’Afrique (1990-2015)

Dans un contexte de déclin de l’adoption internationale qui s’est amorcé en 2005, l’Afrique se présenterait comme une nouvelle frontière de l’adoption. L’African Child Policy, association indépendante africaine, souligne alors que « l'Afrique étant devenue la nouvelle frontière d'adoption internationale, elle a vu, entre 2003 et 2010, le nombre de ses enfants adoptés multiplié par trois ». L’augmentation importante des adoptions internationales dans les principaux pays du continent africain a engendré des questionnements portant sur l’adoptabilité des enfants, la sécurisation et le respect de la législation internationale. La croissance de l’adoption en Afrique a été alors présentée comme génératrice de risques conduisant les pays d’origine tout comme les pays d’accueil à poser des restrictions. Comment la notion de risque peut alors être appréhendée dans un contexte de décroissance de l’adoption internationale ? L’Afrique ne se présente-t-elle pas pourtant comme un continent ouvrant de nouveaux pays d’origine à la pratique de l’adoption ?Against the background of a significant decline of international adoptions, which began in 2005, people seemed to be turning increasingly towards Africa. Indeed, the Africa Child Policy, an independent African association, stressed that “Africa, which had become the new frontier of international adoption, has seen, between 2003 and 2010, a three-fold increase in the number of its adopted children”. The significant increase of international adoptions from the main source countries of the African continent raised several questions, especially on the children’s adoptability, and the respect of international legislation. The growing number of adoptions from Africa was therefore presented as risk inducing, leading countries of origin to impose restrictions on their own territory as well as in receiving countries. Therefore, this study aims to understand how the notion of risk can be understood given the decline of international adoption. The article will also question whether Africa presents itself as a continent of possibly new source countries

Internal dynamics of a medium-sized subarctic lake: field measurements and numerical modeling

As the Arctic Circle opens up due to the effects of global warming, the surrounding regions, and in particular the subarctic zone, experience both climatic and societal changes, which makes it imperative to understand the existing ecosystems. Lake Lagarfljót, an Icelandic fjord lake with glacial inflow, is used to evaluate processes occurring in weakly stratified water bodies in the sub-Arctic. Field observations during the summers of 2010 and 2011 show that the lake experiences a short period of stratification, with overturning occurring when the heat fluxes become negative. The internal-wave regime evolves rapidly as the stratification strengthens, higher vertical modes and Kelvin waves are identified. Glacial inflow to Lake Lagarfljót delivers large volumes of fine sediment. It is expected that most of the sediments remain in suspension and this can alter the density of the water-column, resulting in inverse thermal gradients. Additionally, the glacial river is deflected to the eastern edge of the lake by Coriolis forces, causing the inflow to remain in shallow water before entering the center of the lake. Results from the Münnich model demonstrate that the natural oscillation of the lake basin is close to the oscillation period of the wind. The 3D hydrodynamic model Si3D was adapted to account for suspended sediment, and it successfully reproduced the motions observed in the lake, showing its utility for the study of weakly stratified lakes. Results suggest that wind is the main driver of internal waves in Lake Lagarfljót, but that the river influences stratification, meaning that it cannot be ignored when considering lake circulation. The model confirms the presence of Kelvin waves in the basin. Tracking the pathways of the inflowing glacial water, it appears that the initial intrusion depth is dependent on internal waves. During summertime stratification, the river penetrates the lake as interflows or underflows. Underflows can become trapped, causing them to oscillate and becoming flushed episodically when large glacial discharges enter the lake as underflow. Water entering the lake as interflow mixes more easily and it is flushed quasi-continuously out of the basin. Because the circulation of Lake Lagarfljót is sensitive to the strength of the stratification, the internal dynamics of the lake are expected to change significantly in a warming climate.Hlýnun jarðar hefur mikil áhrif á Norðurskautssvæðinu og þar eru að opnast nýir möguleikar til samgangna og annarra athafna. Hlýnuninni fylgja miklar veðurfars- og samfélagsbreytingar á aðliggjandi svæðum, einkanlega í kaldtempraða beltinu. Áríðandi er að auka skilning á ýmsum vistkerfum á þessu belti og viðbrögðum þeirra við hlýrra loftslagi. Í ritgerð þessari er gerð grein fyrir rannsókn á lagskiptingu í stöðuvatninu Leginum, sem er jökulmyndað vatn efst í Lagarfljóti á Héraði. Vettvangsrannsóknir sem gerðar voru á Leginum sumurin 2010 og 2011 sýna skammæja lagskiptingu sem hverfur þegar hitaflæði verður neikvætt. Innri bylgjukerfi í vatnsbolnum þróast hratt þegar lagskipting styrkist, lóðrétt streymi eykst og Kelvin bylgjur eru sjáanlegar. Jökulsá í Fljótsdal ber með sér mikið magn fíngerðra setagna í Löginn. Viðbúið er að mest af setögnunum haldist í sviflausn og getur það breytt eðlisþyngd vatnssúlunnar, sem veldur viðsnúnum hitastigli. Þar að auki sveigist straumur jökulvatns að eystri bakka Lagarins vegna Coriolis kraftsins og helst því lengur á grynningum en ella áður en það rennur út á mitt stöðuvatnið. Niðurstöður úr Münnich líkaninu sýna að náttúrulegar sveiflur í vatninu eru nálægt sveiflutíma vinds. Þrívíða straumfræðilega reiknilíkanið Si3D var aðlagað til að taka tillit til svifagna. Líkanið endurspeglar innri hreyfingar sem mælast í vatninu og sýnir rannsóknin því fram á nytsemi þessa líkans við greiningu veikrar lagskiptingar í stöðuvötnum. Niðurstöður benda til þess að vindur sé helsti drifkraftur innri bylgjuhreyfinga Lagarins. Áhrif innstreymis Jökulsár á hringrásina í vatninu og þar með á lagskiptinguna eru einnig veruleg. Líkanið staðfestir tilvist Kelvin bylgna í vatninu. Þegar fylgst er með hvernig Jökulsá í Fljótsdal blandast við vatnið virðist innstreymisdýptin í vatnsbolnum vera háð innri bylgjuhreyfingum hans. Við þá lagskiptingu sem ríkir á sumrin rennur áin inn í vatnið sem innra flæði um miðbik vatnsins og eftir botninum sem undirflæði. Vatn sem rennur eftir botninum getur lokast þar af og dýpi þess sveiflast til. Innikróað vatn skolast svo út stöku sinnum þegar mikið af nýju jökulvatni rennur eftir botni vatnsins. Jökulvatn sem berst í vatnið sem innra flæði um miðbik þess blandast betur og skolast nokkuð jafnt út úr því aftur. Þar sem vatnshringrásin í Leginum er háð styrkleika lagskiptingarinnar er viðbúið að innri hrif muni breytast verulega við hækkandi vatnshita.Energy Research Fund of the National Power Company (Landsvirkjun

Exhumation, crustal deformation, and thermal structure of the Nepal Himalaya derived from the inversion of thermochronological and thermobarometric data and modeling of the topography

Two end‐member kinematic models of crustal shortening across the Himalaya are currently debated: one assumes localized thrusting along a single major thrust fault, the Main Himalayan Thrust (MHT) with nonuniform underplating due to duplexing, and the other advocates for out‐of‐sequence (OOS) thrusting in addition to thrusting along the MHT and underplating. We assess these two models based on the modeling of thermochronological, thermometric, and thermobarometric data from the central Nepal Himalaya. We complement a data set compiled from the literature with 114 ^(40)Ar/^(39)Ar, 10 apatite fission track, and 5 zircon (U‐Th)/He thermochronological data. The data are predicted using a thermokinematic model (PECUBE), and the model parameters are constrained using an inverse approach based on the Neighborhood Algorithm. The model parameters include geometric characteristics as well as overthrusting rates, radiogenic heat production in the High Himalayan Crystalline (HHC) sequence, the age of initiation of the duplex or of out-of-sequence thrusting. Both models can provide a satisfactory fit to the inverted data. However, the model with out-of-sequence thrusting implies an unrealistic convergence rate ≥30 mm yr^(−1). The out-of-sequence thrust model can be adjusted to fit the convergence rate and the thermochronological data if the Main Central Thrust zone is assigned a constant geometry and a dip angle of about 30° and a slip rate of <1 mm yr^(−1). In the duplex model, the 20 mm yr^(−1) convergence rate is partitioned between an overthrusting rate of 5.8 ± 1.4 mm yr^(−1) and an underthrusting rate of 14.2 ± 1.8 mm yr^(−1). Modern rock uplift rates are estimated to increase from about 0.9 ± 0.31 mm yr^(−1) in the Lesser Himalaya to 3.0 ± 0.9 mm yr^(−1) at the front of the high range, 86 ± 13 km from the Main Frontal Thrust. The effective friction coefficient is estimated to be 0.07 or smaller, and the radiogenic heat production of HHC units is estimated to be 2.2 ± 0.1 µWm^(−3). The midcrustal duplex initiated at 9.8 ± 1.7 Ma, leading to an increase of uplift rate at front of the High Himalaya from 0.9 ± 0.31 to 3.05 ± 0.9 mm yr^(−1). We also run 3-D models by coupling PECUBE with a landscape evolution model (CASCADE). This modeling shows that the effect of the evolving topography can explain a fraction of the scatter observed in the data but not all of it, suggesting that lateral variations of the kinematics of crustal deformation and exhumation are likely. It has been argued that the steep physiographic transition at the foot of the Greater Himalayan Sequence indicates OOS thrusting, but our results demonstrate that the best fit duplex model derived from the thermochronological and thermobarometric data reproduces the present morphology of the Nepal Himalaya equally well

POM: a Virtual Parallel Machine Featuring Observation Mechanisms

International audienceWe describe in this paper a Parallel Observable virtual Machine (POM), which provides a homogeneous interface upon the communication kernels of parallel architectures. POM was designed so as to be ported easily and eciently on numerous parallel platforms. It provides sophisticated features for observing distributed executions