The enchanted snake and the forbidden fruit: the ayahuasca ‘fairy tale’ tourist

This ethnographic study increases our understanding of Westerners seeking genuine fairy tale experiences of magic, transformation and enchantment within South American psychedelic ayahuasca tourism. Examining 63 tourists, this study shows how vision-based spirit sensegivers facilitate individuals in exorcising demons, to make sense of themselves as spiritual beings within an enchanted universe. However, and with this potion quickly wearing off upon returning to the West, tourists feel abandoned by their spirits, and disconnected from the fairy lands. Coupled with not wanting to re-experience intense inner tensions from stepping in and out of a fairy tale, further tourism is rejected. As such, ayahuasca tourism becomes a ‘forgotten’ fairy tale, rarely told

Numerical Prediction of Multiscale Electronic Conductivity of Lithium-Ion Battery Positive Electrodes

International audienceThe electronic conductivity, at the multiscale, of lithium-ion positive composite electrodes based on LiNi_{1/3}Mn_{1/3}Co_{1/3}O_2 and/or carbon-coated LiFePO_4, carbon black and poly(vinylidene fluoride) mixture is modeled. The electrode microstructures are acquired numerically in 3D by X-ray tomography and FIB/SEM nanotomography and numerically segmented to perform electrostatic simulations using Fast Fourier Transform (FFT) method. Such simulations are easy and quick to perform because they are directly computed on the grid represented by the voxels in the 3D volumes. Numerical results are compared with experimental measurements of the multiscale electronic conductivity by broadband dielectric spectroscopy (BDS). A good prediction is realized for the bulk conductivities of the C/LiFePO_4 phase and the CB/PVdF mixture. The combination of X-ray and FIB/SEM tomography, FFT simulation method, and BDS is thus well adapted to understand the influence of the electrode composition and microstructure on its electronic conductivity

The plant cuticle as an interface between leaves and air-borne pollutants

Material deposited on leaf surfaces may be taken up into the interior either by the stomata! or the cuticular pathway. The uptake of non-volatile substances is restricted to the penetration of the cuticle. The objective of the collaborative work reported here was to characterise important aspects of the interactions between air-borne pollutants and the cuticle of trees. The amounts and composition of the cuticular waxes of the needles of Picea abies and the leaves of Fagus sylvatica were investigated with special attention to the effects of age and environmental factors. The transport properties of plant cuticles were studied using a variety of techniques covering uptake into intact needles, permeability of isolated cuticular membranes and the mobility of permeants in reconstituted cuticular waxes. Effects of polluted sea-spray on the needle surfaces of conifers growing close to the Mediterranean Sea were also investigated

Low (10800 MHz) and high (40 GHz) frequency probes applied to petroleum multiphase flow characterization

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