It starts at home? Climate policies targeting household consumption and behavioral decisions are key to low-carbon futures     

Ghislain Dubois  Benjamin Sovacool  Carlo Aall  Maria Nilsson  Carine Barbier  Alina Herrmann  Sébastien Bruyère  Camilla Andersson  Bore Skold  Franck Nadaud  Florian Dorner  Karen Richardsen Moberg  Jean Paul Ceron  Helen Fischer  Dorothee Amelung  Marta Baltruszewicz  Jeremy Fischer  Françoise Benevise  Valérie R. Louis  Rainer Sauerborn 《Chemie der Erde / Geochemistry》2011

Through their consumption behavior, households are responsible for 72% of global greenhouse gas emissions. Thus, they are key actors in reaching the 1.5 °C goal under the Paris Agreement. However, the possible contribution and position of households in climate policies is neither well understood, nor do households receive sufficiently high priority in current climate policy strategies. This paper investigates how behavioral change can achieve a substantial reduction in greenhouse gas emissions in European high-income countries. It uses theoretical thinking and some core results from the HOPE research project, which investigated household preferences for reducing emissions in four European cities in France, Germany, Norway and Sweden. The paper makes five major points: First, car and plane mobility, meat and dairy consumption, as well as heating are the most dominant components of household footprints. Second, household living situations (demographics, size of home) greatly influence the household potential to reduce their footprint, even more than country or city location. Third, household decisions can be sequential and temporally dynamic, shifting through different phases such as childhood, adulthood, and illness. Fourth, short term voluntary efforts will not be sufficient by themselves to reach the drastic reductions needed to achieve the 1.5 °C goal; instead, households need a regulatory framework supporting their behavioral changes. Fifth, there is a mismatch between the roles and responsibilities conveyed by current climate policies and household perceptions of responsibility. We then conclude with further recommendations for research and policy.  相似文献   

Diffuse and localized failure modes: Two competing mechanisms   总被引：1，自引：0，他引：1  

François Nicot  Félix Darve 《国际地质力学数值与分析法杂志》2011,35(5):586-601

The concept of failure is one of the most debated in soil mechanics, for two reasons essentially. First, this is a crucial issue in the engineering of structures and geotechnical project design. Second, this is still a challenging academic issue mobilizing significant scientific interest in the development of a unique framework to describe the different failure modes. In this respect, this paper revisits the localized failure mode, replacing the well‐known Rice criterion within the wider context of bifurcation. Considering a micro‐mechanical model, the main theoretical results are covered. In particular, it is established that localized failure is a particular case of failures observed within the so‐called bifurcation domain: the incremental strain within the localization band is associated with a vanishing value of the second‐order work. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献   

Comments on “Estimating the Strength of Jointed Rock Masses” by Lianyang Zhang     

Ergin Arıoğlu  Gözde Kurt  Sanem Kayalı 《Rock Mechanics and Rock Engineering》2011,44(4):505-510

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Widespread overspill from a saline density‐current channel and its interaction with topography on the south‐west Black Sea shelf     

Richard N. Hiscott  Ali E. Aksu  Roger D. Flood  Vladimir Kostylev  Doğan Yaşar 《Sedimentology》2013,60(7):1639-1667

Seaward of the Bosphorus Strait, the south‐west Black Sea shelf is dominated by the world's largest channel network maintained by a quasi‐continuous saline (ca 35 → 31 psu) underflow. Calculations indicate that >85% of the initial discharge of ca 10⁴ m³s^?1 spills overbank before the shelf edge. This paper documents interaction of the overspill with sea bed topography using multibeam bathymetry, echo‐sounder images of the water column, conductivity–temperature–depth profiles and sediment cores. Overbank spill is widespread, particularly through crevasse channels and on the middle shelf where confinement by channel banks is negligible. Towards the outer shelf, the wind‐driven Rim Current advects mud along the shelf, contributing to levée successions and deposition on stoss sides of elongate transverse ridges. Echo‐sounder profiles reveal metre‐scale eddies over megaflutes, and breaking lee waves and internal hydraulic jumps over ridges. Megaflutes reach 600 m long and 7 m deep, yet form where the underflow, outside the flute, is no thicker than ca 2 to 5 m. Two types of elongate seaward‐facing ridges are recognized. Type 1 ridges, 2 to 5 m high, consist of bivalve‐rich muddy sand in low‐angle (3·5° to 6°) cross‐sets created by the underflow. Type 2 ridges, ca 5 m high, have crests up to 2 km long and a buried wedge‐shaped foundation (the ‘ridge‐core’) comprised of facies similar to Type 1 ridges. These ridge‐cores are blanketed on the landward side by stratified muds, and are capped by obliquely oriented ribs supporting a diverse benthic community. This facies distribution is interpreted to result from stoss‐side and lee‐side velocity and turbulence fluctuations induced by internal hydraulic jumps and breaking lee waves in overspilling portions of the underflow. Experimental results published by W.H. Snyder and co‐workers effectively explain ridge evolution and flow across the ridges, and therefore can be applied with confidence to less easily studied deep‐marine settings swept by turbidity currents.  相似文献   

Phyllosilicates synthesis: a way of accessing edges contributions in NMR and FTIR spectroscopies. Example of synthetic talc     

Angela Dumas  François Martin  Christophe Le Roux  Pierre Micoud  Sabine Petit  Eric Ferrage  Jocelyne Brendlé  Olivier Grauby  Mike Greenhill-Hooper 《Physics and Chemistry of Minerals》2013,40(4):361-373

A series of new-generation synthetic talcs were prepared by varying the hydrothermal synthesis duration from a few hours up to 2 months. Crystallinity and particle size analysis of the synthetic products were evaluated by photon correlation spectroscopy, transmission electron microscopy, differential thermal analysis and unoriented X-ray diffraction, and then analyzed by various spectroscopic methods such as Fourier transformed infrared spectroscopy and solid-state ¹H and ²⁹Si magic angle spinning nuclear magnetic resonance. The new process for preparing synthetic talcs allows to obtain single-phased particles which after few hours grow heterogeneously and simultaneously in both the c* direction and the (ab) plan. Fine particles, observed for whatever the synthesis duration, lead to the presence of numerous sheet edges surfaces due to particle size which represents the main difference with natural talc. Spectroscopy data show the influence of the fine particles on signals and highlight that synthetic talc characterization is a potential tool for better understanding crystal chemistry of natural talc.  相似文献   

Comprehensive physicochemical study of dioctahedral palygorskite-rich clay from Marrakech High Atlas (Morocco)     

Benaissa Rhouta  Ezzouhra Zatile  Lahcen Bouna  Omar Lakbita  Francis Maury  Lahcen Daoudi  Marie Christine Lafont  M’Barek Amjoud  François Senocq  Amane Jada  Ahmed Aït Aghzzaf 《Physics and Chemistry of Minerals》2013,40(5):411-424

This study is devoted to the physicochemical and mineralogical characterizations of palygorskite from Marrakech High Atlas, Morocco. The raw clay and its Na⁺-saturated <2 μm fraction were characterized using chemical, structural, and thermal analytical techniques. Measurements of specific surface area and porous volume are reported. The clay fraction was found to be made up of 95 % of palygorskite and 5 % of sepiolite. An original feature of this palygorskite is its deficiency in zeolitic H₂O. The half-cell structural formula of its dehydrated form was determined on the basis of 21 oxygens to be (Si_7.92Al_0.08)(Mg_2.15Al_1.4Fe_0.4Ti_0.05 $ \square_{1} $ )(Ca_0.03Na_0.08K_0.04)O₂₁, while the hydrated form could be formulated as (Si_7.97Al_0.03)(Mg_2.17Al_1.46Fe_0.40Ti_0.05)(Ca_0.03Na_0.07K_0,03)O_20.18(OH)_1.94(OH₂)_3.88·2.43 H₂O. These formulas show that the (Al³⁺+Fe³⁺)/Mg²⁺ ratio is around 0.84, revealing a pronounced dioctahedral character. Further, inside its octahedral sheet, it was determined that the inner M₁ sites are occupied by vacancies, whereas the M₂ sites are shared between 90 % of trivalent cations (78 % for Al³⁺ and 22 % for Fe³⁺), 7.5 % of Mg²⁺, and 2.5 % of Ti⁴⁺, all of them linked to 1.94 of structural hydroxyls. The two remaining Mg²⁺ by half-cell occupy edge M₃ sites and are coordinated to 3.88 molecules of OH₂. Channels of this palygorskite are deficient in zeolitic H₂O since they contain only 2.43 H₂O molecules. A correlation was found between these results and the observation of very intense and well-resolved FTIR bands arising from dioctahedral domains (mainly Al₂OH, Fe₂OH, and AlFeOH) along with very small responses from a trioctahedral domain (Mg₃OH). Accordingly, a schematic representation of the composition of the octahedral sheet was proposed. The cation exchange capacity, specific surface area, and total pore volume were also assessed to be ca. 21.2 meq/100 g, 116 m²/g, and 0.458 cm³/g, respectively.  相似文献   

Hydromechanical Analysis of Masonry Gravity Dams and their Foundations   总被引：1，自引：1，他引：0  

Eduardo M. Bretas  José V. Lemos  Paulo B. Lourenço 《Rock Mechanics and Rock Engineering》2013,46(2):327-339

A numerical model for the hydromechanical analysis of masonry dams based on the discrete element method is presented. The dam and the rock foundation are represented as block assemblies, and a coupled flow-stress analysis is performed in an integrated manner for the entire system. Complex block shapes may be obtained by assembling elementary blocks into macroblocks, allowing the application of the model to situations ranging from equivalent continuum to fully discontinuum analysis. A contact formulation was developed based on an accurate edge–edge approach, incorporating mechanical and hydraulic behavior. The main numerical aspects are described, with an emphasis in the flow analysis explicit algorithm. An application to an existing masonry dam is presented, analyzing its present condition, with excessive seepage, and the proposed rehabilitation intervention. An evaluation of sliding failure mechanisms was also performed, showing the expected improvement in the safety of the structure.  相似文献   

Monitoring deformations on engineering structures in Kozlu Hard Coal Basin   总被引：2，自引：1，他引：1  

Eray Can  Çetin Mekik  Şenol Kuşcu  Hakan Akçın 《Natural Hazards》2013,65(3):2311-2330

Underground coal mining activities in Kozlu Hard Coal Basin have reached a level affecting ground layers inside the mining seams and the surface just above the mining operations, causing movements in vicinity of the basin. The movements emerge as collapsing in vertical direction and as sliding, curling and bending in horizontal direction and are termed mining subsidence since they exhibit themselves in ground layers and on earth surfaces in mining environments. These mining-induced movements cause damages and destructions on structures inside and on the surface of mining grounds, and the dimensions of these damages depend upon quality of structures and magnitude of movements. In order to contribute toward a solution to these problems and to mitigate the effects arising during and after mining activities, one should identify and investigate damage prone movements and determine the movement–time relationship. Therefore, it is immensely important to observe, investigate, and measure these movements in regions where mining activities take place. This study focuses on the surface movement-related deformations on the engineering structures in the basin such as Kozlu Seaport and some part of the Zonguldak-Kozlu Road. For this reason, subsidence monitoring points were established on the engineering structures in the basin in a geodetic network concept, and three periods of precise leveling and static GPS observations were conducted. Analyzing these two types of geodetic observations, active and residual subsidence effects were determined for both Kozlu Seaport and the Road nearby.  相似文献   

L’ouverture de l’Atlantique et son influence sur les peuplements des grands foraminifères des plates-formes péri-océaniques au Mésozoïque     

Eric Fourcade  François Michaud 《Geodinamica Acta》2013,26(4-5):247-262

Résumé

— Au Jurassique et au Crétacé, le peuplement des plates-formes des marges atlantiques par les grands foraminifères benthi-ques s’est opéré d’Ouest en Est. Caractéristiques des zones tropicales ces organismes n’ont atteint la marge américaine de l’océan qu’au Callovien ou à l’Oxfordien. Jusqu’au Sénonien, les grands forammifères de cette marge étaient peu diversifiés; ils appartenaient à des espèces bien connues sur la marge européenne et africaine ainsi que dans la Néoléthys méditerranéenne où les grands foraminifères benthiques sont très diversifiés. Néanmoins un faible endémisme est apparu pendant l’Albien sur la marge américaine de l’océan.

D’une façon générale, la faible diversité des formes américaines est sans doute liée à la faible largeur qu’avait alors l’Océan Atlantique petit bassin océanique entre deux super continents, et aux instabilités climatiques que cette situation pouvait engendrer.

Un important changement est intervenu au Campanien où le peuplement des plates-formes carbonatées américaines a montré une grande diversité et un fort taux d’endémisme. Ceci peut être lié pour partie à la largeur notable qu’atteignait alors l’Atlantique aussi bien dans sa partie centrale que méridionale, isolant ainsi la marge américaine de la marge européenne et africaine.

S’agissant du régime climatique, la distribution des grands foraminifères au Jurassique supérieur-Crétacé inférieur montre qu’un même régime tropical régnait alors du Guatemala à Terre Neuve et du Sénégal à la Bretagne sur les deux rivages. Au Crétacé supérieur, les grands foraminifères ne sont connus qu’aux basses latitudes sur la rive américaine (Texas, Floride, Bahamas) tandis qu’ils sont relativement abondants aux latitudes élevées sur la marge européenne (Hollande, Suède méridionale). Il est probable qu’un paléo-Gulstream réchauffait alors les côtes septentrionales de l’Europe.  相似文献   

Appareils gravitaires et évolution mégaséquentielle du Numidien dans le Nord et I’Est de la Grande Kabylie     

François Laval 《Geodinamica Acta》2013,26(4):217-233

Résumén

L’analyse séquentielle et la sédimentologie de faciès sont appliquées aux grès numidiens. Ces méthodes fournissent des données nouvelles concernant l’origine de ces dépôts. Ceux-ci présentent des associations de faciès proximales et résultent de transports sur des distances relativement courtes. On n’observe pas de dépôts distaux. Plusieurs dépo-centres sableux. vraisemblablement des éventails radiaux, de vraient être répartis tout le long d’un bassin. Ces données rendent difficile de situer ce bassin au Sud des « noyaux » kabyles, ceux-ci fournissant à cette époque un matériel terrigène déposé en discordance ou alimentant les grès micacés » périphériques; la bordure « tellienne » ne semblant pas non plus avoir pu laisser transiter des sables (transports continentaux puis marins). Il est donc logique de placer le bassin au nord des « noyaux » kabyles. Cependant, la question de l’origine continentale du matériel quart/eux n’étant pas réglée (Afrique ou continent septentrional), celte position pose le problème paléogéographique de la disposition des terres ou des deltas ayant permis le drainage continental de ces sables jusqu’aux points d’entrée sous-marine.  相似文献