37 research outputs found
State-building, war and violence : evidence from Latin America
In European history, war has played a major role in state‐building and the state monopoly on violence. But war is a very specific form of organized political violence, and it is decreasing on a global scale. Other patterns of armed violence now dominate, ones that seem to undermine state‐building, thus preventing the replication of European experiences. As a consequence, the main focus of the current state‐building debate is on fragility and a lack of violence control inside these states. Evidence from Latin American history shows that the specific patterns of the termination of both war and violence are more important than the specific patterns of their organization. Hence these patterns can be conceptualized as a critical juncture for state‐building. While military victories in war, the subordination of competing armed actors and the prosecution of perpetrators are conducive for state‐building, negotiated settlements, coexistence, and impunity produce instability due to competing patterns of authority, legitimacy, and social cohesion
Non-destructive testing of works of art by stimulated by infrared thermography: PPT interest
Short abstract Within the framework of the cultural heritage conservation, stimulated infrared thermography has already demonstrated its efficiency. However, sometimes, the different colors of the paint layer can lead to artifacts of detection. In this work, we show theoretically and experimentally that the combination of a PPT analysis and of the stimulated infrared thermography allows a significant reduction of this disturbing optical effect
Stimulated infrared thermography applied to the local thermal characterization of fresco
Abstract In this work, we present a new method for estimating the local thermal diffusivity of fresco. This method uses a temporal analysis of the thermal response of a work of art submitted to a local laser excitation. First, we present the principle of the estimation method. Then, we show theoretically with the help of numerical simulations, the feasibility of the method. Finally, we show experimentally, that the method allows a good estimation of the thermal diffusivity of an academic plaster sample and of an academic fresco
Novel approach of signal normalization for depth profile of cultural heritage materials
International audienc
Duvaut : Contribution to the local thermophysical characterization of murals paintings of the inheritance by stimulated infra-red thermography, proc of QIRT
Abstract The object of this work is to approach the possibilities of stimulated infrared thermography for in situ measurement of thermal diffusivity of mural paintings of the inheritance. We present first the principle of the method. We show then the feasibility of the measurement, using theoretical simulations. Finally, we show that the method allows a good estimation of the thermal diffusivity of a partial copy of the "Saint Christophe" of the Campana collection in the Louvre
Low-coherence interferometry \ue2\u20ac\u201c an advanced technique for optical metrology in industry
Low-coherence interferometry (LCI) is an optical technique that may be used for industrial surface metrology with accuracy in the micron range. An instrument made with optical ibres is rugged enough to be used in industrial environments and the ibre-linked optical probe may be miniaturised for accessing tight locations. Among industrial applications developed at IMI, several cases for which LCI has been particularly useful, such as an elongational rheometer (RME), characterisation of wear damages on coating and laser-induced breakdown spectroscopy (LIBS), will be presented. The RME is an instrument in which a polymer sample is stretched in a controlled temperature furnace at up to 350\uc2\ub0C. LCI has been used for monitoring the thickness of the samples. Wear damage is quantiied by the volume loss after a wear test. It requires a high depth resolution (axis perpendicular to the surface) but a relatively coarse transverse resolution. The LIBS is a technique that has been used for analysing the chemical composition of materials as a function of depth. LCI has been integrated to a LIBS instrument for measuring accurately the crater depth between each laser shot.Peer reviewed: YesNRC publication: Ye