Time filter

Source Type

Toulouse, France

Ferdian D.,ENSIACET | Ferdian D.,University of Indonesia | Josse C.,ENSIACET | Nguyen P.,French National Center for Space Studies | And 7 more authors.
Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science | Year: 2015

The microstructure of a high-purity Al-6.5Si-1Fe (wt pct) alloy after solidification at various cooling rates was investigated. In most of the cases, the monoclinic beta-Al9Fe2Si2 phase was observed as long and thin lamellae. However, at a very slow cooling rate, Fe-bearing precipitates with Chinese script morphology appeared together with lamellae. Further analysis showed all these Chinese script precipitates correspond also to the monoclinic beta phase. This finding stresses that differentiating second phases according to their shape may be misleading. © 2015, The Minerals, Metals & Materials Society and ASM International. Source

Font E.,University of Lisbon | Nedelec A.,GET | Ellwood B.B.,Louisiana State University | Mirao J.,HERCULES | Silva P.F.,University of Lisbon
Geophysical Research Letters | Year: 2011

The origin of the Cretaceous-Paleogene boundary (KPB) mass extinction is still the center of acrimonious debates by opposing partisans of the bolide impact theory to those who favored a terrestrial origin linked to the Deccan Traps volcanism. Here we apply an original and high-resolution environmental magnetic study of the reference Bidart section, France. Our results show that the KPB is identified by an abrupt positive shift of the magnetic susceptibility (MS), also observed by others at the KPB elsewhere. In addition, an anomalous interval of very low MS, carried by an unknown Cl-bearing iron oxide similar to specular hematite, is depicted just below the KPB. Grain-size and morphology of the Cl-iron oxide are typically in the range of hematitic dust currently transported by winds from Sahara to Europe. This discovery is confirmed in the referenced Gubbio section (Italy) suggesting a global scale phenomenon. As a conjecture we suggest an origin by heterogeneous reaction between HCl-rich volcanic gas and liquid-solid aerosols within buoyant atmospheric plumes formed above the newly emitted Deccan flood basalts. Based on this hypothesis, our discovery provides a new benchmark for the Deccan volcanism and witnesses the nature and importance of the related atmospheric change. Copyright © 2011 by the American Geophysical Union. Source

Thomas M.S.,Jamia Millia Islamia University | Bansal P.,MItsubishi Electric | Taneja P.,GET
India International Conference on Power Electronics, IICPE | Year: 2015

This paper includes an HEM algorithm for managing household power-intensive appliances. The highlight of the proposed HEM algorithm is its ability to control selected appliances and keep the total household power consumption below a certain limit, while considering customer preferences and allowing the customer more flexibility to operate their appliances. Advanced Metering Infrastructure (AMI) coupled with Demand Response enables to relieve the stress on the Power System at the times of peak load while simultaneously shifting it to non-peak periods which enables us to achieve a higher load factor and consequently, cheaper cost of production of electricity. This paper presents a prototype of a Smart Controller working on the principle of Demand Response for managing high power consumption household appliances. The controller manages household loads according to their preset priority and guarantees the total house-hold power consumption below certain levels. A hardware model has been developed on an Arduino board to showcase the applicability of the proposed algorithm in performing DR at a lumped load level. © 2014 IEEE. Source

Blanc P.,Bureau de Recherches Geologiques et Minieres | Lassin A.,Bureau de Recherches Geologiques et Minieres | Piantone P.,Bureau de Recherches Geologiques et Minieres | Azaroual M.,Bureau de Recherches Geologiques et Minieres | And 3 more authors.
Applied Geochemistry | Year: 2012

The development of Thermoddem, a thermodynamic database devoted to geochemical modelling for environmental studies in general and, more specifically, to chemical systems involving waste materials, is discussed here. Concerns are also focused on taking into account some specific needs for modellers by proposing different output formats and some important information concerning the solid phases, the transformation path, paragenesis and insights into crystallographic details. This additional information aims to avoid considering phases that may not be "active" under current environmental conditions. The database is especially devoted to environmental applications, ranging from waste material management to pollutant behaviour, including the context of deep underground disposal. Selection rules and conventions are illustrated through the example of the Fe-water system, while a second example details the relationships between low and high ionic strength media, from the point of view of thermodynamic databases. Technical aspects concerning the development of a management information system for Thermoddem and its availability on the web (http://thermoddem.brgm.fr) are also provided. © 2012 Elsevier Ltd. Source

Adam C.,Virginia Polytechnic Institute and State University | King S.D.,Virginia Polytechnic Institute and State University | Vidal V.,Ecole Normale Superieure de Lyon | Rabinowicz M.,GET | And 2 more authors.
Earth and Planetary Science Letters | Year: 2015

The subsidence of young seafloor is generally considered to be a passive phenomenon related to the conductive cooling of the lithosphere after its creation at mid-oceanic ridges. Recent alternative theories suggest that the mantle dynamics plays an important role in the structure and depth of the oceanic lithosphere. However, the link between mantle dynamics and seafloor subsidence has still to be quantitatively assessed. Here we provide a statistical study of the subsidence parameters (subsidence rate and ridge depth) for all the oceans. These parameters are retrieved through two independent methods, the positive outliers method, a classical method used in signal processing, and through the MiFil method. From the subsidence rate, we compute the effective thermal conductivity, keff, which ranges between 1 and 7 W m-1 K-1. We also model the mantle flow pattern from the S40RTS tomography model. The density anomalies derived from S40RTS are used to compute the instantaneous flow in a global 3D spherical geometry. We show that departures from the keff=3 Wm-1K-1 standard value are systematically related to mantle processes and not to lithospheric structure. Regions characterized by keff>3 Wm-1K-1 are associated with mantle uplifts (mantle plumes or other local anomalies). Regions characterized by keff<3 Wm-1K-1 are related to large-scale mantle downwellings such as the Australia-Antarctic Discordance (AAD) or the return flow from the South Pacific Superswell to the East Pacific Rise. This demonstrates that mantle dynamics plays a major role in the shaping of the oceanic seafloor. In particular, the parameters generally considered to quantify the lithosphere structure, such as the thermal conductivity, are not only representative of this structure but also incorporate signals from the mantle convection occurring beneath the lithosphere. The dynamic topography computed from the S40RTS tomography model reproduces the subsidence pattern observed in the bathymetry. Overall we find a good correlation between the subsidence parameters derived from the bathymetry and the dynamic topography. This demonstrates that these parameters are strongly dependent on mantle dynamics. © 2015 Elsevier B.V. Source

Discover hidden collaborations