The color of transformation: Investigations into heat treatment of Natufian artifacts from Hayonim Terrace (Israel)

In the Natufian lithic component at Hayonim, both in the cave and the terrace, numerous artifacts of pink/red color may be recognized. Cherts with similar appearance are not present in the geological environment surrounding the site in Northern Israel. Pink chert available in Jordan is shown to be of different nature. Thus this leaves us with the hypothesis of intentional heat treatment of locally available iron-rich yellow chert, of Cenomanian age. Based on experimental replication of chert firing and SEM analysis, we argue that a well-mastered and controlled use of fire was practiced by some skilled craftsmen at Hayonim throughtout the Late Epipalaeolithic

El nuevo contexto de la política exterior china

El nuevo poder chino y su sus efectos sobre el equilibrio regional y global. En algún momento entre 2003 y 2004, el mundo dejó de preguntarse si China se había convertido o no una gran potencia; abiertamente se le empezó a tratar como tal. Se asumió que la República Popular no era sólo un gigante demográfico cuya economía llevaba dos décadas y media creciendo a un alto ritmo sostenido. Ya no podía obviarse por más tiempo que ese crecimiento tenía unas implicaciones internacionales. El extraordinario grado de apertura de su economía al exterior y la adhesión a la Organización Mundial de Comercio aceleraron la integración de China en la economía global y le dieron en 2004 el cuarto mayor PIB del planeta (convertido ya en el tercero en 2007). El impacto global del ascenso chino no es, sin embargo, sólo económico. Por las mismas fechas Pekín ejercía un activismo diplomático desconocido hasta entonces que revelaba su decisión de ejercer una mayor influencia política. De Sudán a Irán, de América Latina a Corea del Norte, China se ha convertido en un actor con el que ya no se puede dejar de contar. Esa creciente proyección política se ve reforzada asimismo por la mejora de las capacidades militares chinas, cuya finalidad inquieta tanto a sus vecinos como a Estados Unidos. Por lo demás, en su nueva estrategia internacional Pekín tampoco ha olvidado la dimensión cultural y de “soft power”, demostrando un buen conocimiento de las fuerzas globales

On the thermal impact on the excavation damaged zone around deep radioactive waste disposal

International audienceClays and claystones are considered in some countries (including Belgium, France and Switzerland) as a potential host rock for high activity long lived radioactive waste disposal at great depth. One of the aspects to deal with in performance assessment is related to the effects on the host rock of the temperature elevation due to the placement of exothermic wastes. The potential effects of the thermal impact on the excavated damaged zone in the close field are another important issue that was the goal of the TIMODAZ European research project. In this paper, some principles of waste disposal in clayey host rocks at great depth are first presented and a series of experimental investigations carried out on specific equipment specially developed to face the problem are presented. Both drained and undrained tests have been developed to investigate the drained thermal volume changes of clays and claystone and the thermal pressurization occurring around the galleries. This importance of proper initial saturation (under in-situ stresses) and of satisfactory drainage conditions (in spite of the significantly low permeability of claystones) is emphasized, leading to the development of a new hollow cylinder apparatus. It is observed that claystones cannot be considered as overconsolidated clays given that they can exhibit, as the Callovo-Oxfordian claystone does, a thermoplastic contraction. Mechanical and thermal hardening are however observed, extending to claystones the knowledge already gained on clays. A new method of determining in the laboratory the thermal pressurization coefficient is described and the data obtained allow completing existing data in the field. Finally, the hollow cylinder apparatus makes it possible to demonstrate that the good self-sealing properties of clays and claystones can be extended to temperature effects, an important conclusion in terms of performance assessment

L’ouverture des camps et les gestes d’attestation cinématographique des Alliés (1944-1945)

Les Alliés — Russes, Américains et Britanniques — sont confrontés en 1944-1945 à la vision des camps d’extermination et de concentration nazis. Ce qu’ils entreprennent alors tient du geste documentaire de l’enregistrement filmique, mais également de la tentative d’imaginer les conditions de détention et de mise à mort des déportés. La sidération première fait place à différentes pratiques tenant d’une volonté d’attestation : la substitution (le remplacement des images nazies détruites ou inexistantes par celles des Alliés) et la confrontation directe des Allemands aux crimes commis dans les camps, par exemple. C’est, entre autres, le cas de Samuel Fuller à Falkenau, qui mène là-bas une expérimentation annonciatrice des préoccupations techniques, esthétiques et éthiques du néoréalisme italien.The Allies—Russian, American and British—were confronted in 1944–45 with the image of Nazi extermination and concentration camps. The result was a desire to document and record on film, but also an attempt to imagine the conditions under which deportees were detained and put to death. The initial shock gave way to various attempts to provide testimonials, from the substitution and replacement of destroyed or non-existent Nazi images to directly confronting Germans with the crimes committed in the camps. This was the case of Samuel Fuller’s experience at Falkenau, a precursor in its technical, aesthetic and ethical concerns to Italian Neo-realism