Thermal imaging on simulated faults during frictional sliding

Heating during frictional sliding is a major component of the energy budget of earthquakes and represents a potential weakening mechanism. It is therefore important to investigate how heat dissipates during sliding on simulated faults. We present results from laboratory friction experiments where a halite (NaCl) slider held under constant load is dragged across a coarse substrate. Surface evolution and frictional resistance are recorded. Heat emission at the sliding surface is monitored using an infra-red camera. We demonstrate a link between plastic deformations of halite and enhanced heating characterized by transient localized heat spots. When sand 'gouge' is added to the interface, heating is more diffuse. Importantly, when strong asperities concentrate deformation, significantly more heat is produced locally. In natural faults such regions could be nucleation patches for melt production and hence potentially initiate weakening during earthquakes at much smaller sliding velocities or shear stress than previously thought

International Integration of Chinese Regions and industrial location

This paper has two main objectives : first, to evaluate and to analyse the spatial concentration of industry in China; second, to estimate a link between the openness of China and this concentration. We are interested in the evolution of industrial location to study the regional specialisations. To explain increasing disparities we perform an econometric investigation, derived from the economic geography models, to test the impact of foreign trade on industrial location between the Chinese regions.China, regions, localisation, geographic economics

A new blind adaptive antenna array for GNSS interference cancellation

This paper introduces a new blind adaptive antenna array as a possible solution to the interference cancellation problem. This new technique is compared to three classical ones over two different sensor radiation patterns. Special attention is paid to the array compatibility with a conventional GNSS receiver. A wide radiation pattern sensor is shown to improve the positioning accuracy by maximizing the satellite constellation visibility. Finally, the new processor demonstrates its superiority in term of positioning accuracy in presence of strong interferences. However, its phase response may make it incompatible with classical GNSS receivers. Some efforts must be done to stabilize it

Are There Spillover Effects Between Coastal and Non-Coastal Regions in China ?

The evolution of regional policy between the Mao era and the Deng era generated much debate concerning inter-provincial disparities and the trade-off between efficiency and equity. The aim of this paper is to explore the existence of regional growth spillover effects looked for Deng’s policy. Indeed, the main objective was the spread of coastal provinces’ growth onto inland provinces’ growth. After reviewing the theoretical underpinnings of such effects, their existence is tested with panel data, for the period 1981-1998. Moreover, the hypothesis of an equal distribution of these effects over all the inland provinces is also tested. A relative failure to boost development of the western provinces from the coastal provinces’ growth is observed. Hence, it would seen to be an error to wait for spillover effects to be sufficient to reduce disparities between Chinese provinces in the short run.panel data., spillover effects, regions, growth, China

Rhombohedral calcite precipitation from CO2-H2O-Ca(OH)2 slurry under supercritical and gas CO2 media

The formation of solid calcium carbonate (CaCO3) from aqueous solutions or slurries containing calcium and carbon dioxide (CO2) is a complex process of considerable importance in the ecological, geochemical and biological areas. Moreover, the demand for powdered CaCO3 has increased considerably recently in various fields of industry. The aim of this study was therefore to synthesize fine particles of calcite with controlled morphology by hydrothermal carbonation of calcium hydroxide at high CO2 pressure (initial PCO2=55 bar) and at moderate and high temperature (30 and 90 degrees C). The morphology of precipitated particles was identified by transmission electron microscopy (TEM/EDS) and scanning electron microscopy (SEM/EDS). In addition, an X-ray diffraction analysis was performed to investigate the carbonation efficiency and purity of the solid product. Carbonation of dispersed calcium hydroxide in the presence of supercritical (PT=90 bar, T=90 degrees C) or gaseous (PT=55 bar, T=30 degrees C) CO2 led to the precipitation of sub-micrometric isolated particles (<1$\mu$m) and micrometric agglomerates (<5$\mu$m) of calcite. For this study, the carbonation efficiency (Ca(OH)2-CaCO3 conversion) was not significantly affected by PT conditions after 24 h of reaction. In contrast, the initial rate of calcium carbonate precipitation increased from 4.3 mol/h in the "90bar-90 degrees C" system to 15.9 mol/h in the "55bar-30 degrees C" system. The use of high CO2 pressure may therefore be desirable for increasing the production rate of CaCO3, carbonation efficiency and purity, to approximately 48 kg/m3h, 95% and 96.3%, respectively in this study. The dissipated heat for this exothermic reaction was estimated by calorimetry to be -32 kJ/mol in the "90bar-90 degrees C" system and -42 kJ/mol in the "55bar-30 degrees C" system

Increased Exposure of China to Asymmetric External Shocks: Is Fiscal Federalism an Efficient Answer?

The aim of this paper is to examine whether there is a co-insurance mechanism against provincial aggregate income fluctuations between the Chinese provinces. Our theoretical argument relies on the existence of an efficient allocation of risk between the Chinese provinces. According to this analysis, an institutional arrangement between the provinces allows the perfect smoothing of provincial private consumption. In this case, changes in provincial private consumption depend rather on changes in aggregate Chinese income than on asymmetric changes in provincial income. We test this hypothesis on the 1989-2000 period for 30 Chinese provinces using the GMM estimator. Econometric evidence highlights the weakness of co-insurance mechanisms between the Chinese provinces. First, we reject the hypothesis of perfect insurance. Second, there does not seem to exist a significant, though imperfect, insurance mechanism. Indeed, the provinces’ private consumption reactions are the same either after a shock affecting all the provinces or after an asymmetric shock.China., Fiscal Federalism, Regional Economics Risk Coping, Co-insurance