Enacting Higher Order Thoughts: Velazquez and Las Meninas

This paper bridges art history and consciousness studies and investigates the network of gazes and frames in Las Meninas and how this engages with a system of higher-order thoughts and reflexive operations

Beyond Internalism and Externalism: Husserl and Sartre’s Image Consciousness in Hitchcock and Buñuel

Husserl and Sartre’s analyses of mental imagery and some of the latest cognitive research on vision provide a framework for understanding a number of films by Hitchcock  (Psycho and Rear Window) and Buñuel (Un Chien Andalou), films which similarly probe the subtleties and uses of mental imagery. One of the many ways to enjoy these films is to see them as explorations of visual phenomenology; they allow us to enact, as well as reflect upon, mental images as part of the film experience

Optical properties, surface composition and desorption of Stainless Steel (316L) studied from ambient temperature to 1000 K in vacuum

International audienceStainless steels are widely used as structural materials due to their excellent corrosion resistance and fabricability. In some applications, in nuclear fusion reactors for instance, these materials may be exposed to harsh conditions, including high heat flux and ion bombardment in a vacuum environment, which can significantly affect their surface properties and composition. In this work, we investigate the temperature-dependent evolution of the surface composition and optical properties (reflectivity, emissivity) of stainless steel 316L. X-ray photoelectron spectroscopy analyses, temperature programmed desorption and reflectivity measurements in the visible/near-infrared range were performed on polished samples from ambient temperature to 1000 K. It was found that around 750 K, the initial Fe/Cr surface abundance of 90/10 changes to 35/55 following the onset of Cr and CrO desorption at 575 K, with Cr scavenging oxygen initially bound to Fe. In addition, Mn segregated at the surface and oxidized, while small amounts of metallic Ni segregated. Despite these modifications in surface composition, no significant change in reflectivity up to 900 K was observed. These results provide insight into the behavior of stainless steel under extreme conditions which is relevant for understanding its performance and durability in high-temperature applications

The Artist as Curator

"In recent years, the museum and gallery have increasingly become self-reflexive spaces, in which the relationship between art, its display, its creators, and its audience is subverted and democratized. One effect of this has been a growing place for artists as curators, and in The Artist as Curator Celina Jeffery brings together a group of scholars and artists to explore the many ways that artists have introduced new curatorial ways of thinking and talking about artistic culture. Taking a deliberately multidisciplinary and cross-cultural focus, The Artist as Curator will fill a gap in museum and curatorial studies, offering a thorough and diverse treatment of various approaches to the historical and changing role of the artist as curator that should appeal to scholars, curators, and artists alike." - Publisher's website

Optical Properties of Tungsten: A Parametric Study to Characterize the Role of Roughness, Surface Composition and Temperature

International audienceTungsten (W) is the material selected for the divertor exhaust of the international nuclearfusion experiment ITER. In this harsh environment, the interactions of heat loads and ion fluxes withW can induce temporary or permanent evolution in the optical properties. Poor knowledge of suchevolution during a plasma operation can lead to errors in temperature measurements performed byoptical diagnostics. Therefore, it is of fundamental importance to characterize possible changes in Woptical properties. In this work, we studied the role of morphology and temperature on the opticalresponse of W. The reflectivities of five W samples with different roughness values (20–100 nm) weremeasured during laser annealing (25–800 °C) in the visible and near-infrared domains (500–1100 nm).We observed an increase in reflectivity after annealing and we demonstrated that it was due to achange in the chemical composition of the surface, in particular a reduction in the amount of nativeoxide. Moreover, we show that roughness does not sensibly vary in the investigated temperaturerange. By highlighting the role played by roughness and surface impurities (e.g., oxide), we provideinsight in how W optical properties can evolve in tokamaks where high ion fluxes, heat loads, andimpurities can induce the evolution of both the morphology and surface composition of W

Post-mortem analysis of tungsten plasma facing components in tokamaks: Raman microscopy measurements on compact, porous oxide and nitride films and nanoparticles

International audienceRaman microscopy is one of the methods that could be used for future post-mortem analyses of samples extracted from ITER plasma facing. This study shows that this technique is useful for studying tungsten-based materials containing impurities including oxides and nitrides. Here, we apply pulsed laser deposition and DC argon glow discharges to produce tungsten-containing synthetic films (compact, porous) and nanoparticles and investigate the influence of their morphology on the measured Raman spectra. The amounts of oxygen and/or nitrogen in the films are also investigated. Comparative data are obtained by X-ray Photoelectrons Spectroscopy, Atomic Force Microscopy, Electron Microscopies (Scanning and Transmission), Energy Dispersive X-ray spectroscopy, Time-of-Flight Elastic Recoil Detection Analysis. The power density of the laser beam used to perform Raman microscopy is varied by up to 4 orders of magnitude (0.01-20 mW/μm 2) to investigate thermal stability of films and nanoparticles. As a first result, we give evidence that Raman microscopy is sensitive enough to detect surface native oxides. Secondly, more tungsten oxides are detected in porous materials and nanoparticles than in compact films, and the intensities of the Raman band correlate to their oxygen content. Thirdly, thermal stability of these films (i.e. structural and chemical modification under laser heating) is poor when compact films contain a sufficiently large amount of nitrogen. This finding suggests that nitrogen can be substituted by oxygen during Raman laser induced heating occurring in ambient air. Finally, our methodology can be used to rapidly characterize morphology and chemistry of the samples analyzed, and also to create oxides at the micrometer scale. keywords: PLD, Raman spectroscopy, tungsten oxide, tungsten nitride, plasma wall interaction, laser heating, post-mortem analysis