Logarithmic Yangians in WZW models

A new action of the Yangians in the WZW models is displayed. Its structure is generic and level independent. This Yangian is the natural extension at the conformal point of the one unravelled in massive theories with current algebras. Expectingly, this new symmetry of WZW models will lead to a deeper understanding of the integrable structure of conformal field theories and their deformations.Comment: 8 pages, TeX, harvmac, 2 .eps figure

S-matrix of N=2 Supersymmetric Sine-Gordon Theory

We investigate the S-matrix of N=2 supersymmetric sine-Gordon theory based on the N=2 supersymmetry and the quantum group structure. The topological charges play an important role to derive physical contents.Comment: 17 page

Emulsions stabilised by whey protein microgel particles: Towards food-grade Pickering emulsions

We have investigated a new class of food-grade particles, whey protein microgels, as stabilisers of triglyceride-water emulsions. The sub-micron particles stabilized oil-in-water emulsions at all pH with and without salt. All emulsions creamed but exhibited exceptional resistance to coalescence. Clear correlations exist between the properties of the microgels in aqueous dispersion and the resulting emulsion characteristics. For conditions in which the particles were uncharged, fluid emulsions with relatively large drops were stabilised, whereas emulsions stabilized by charged particles contained smaller flocculated drops. A combination of optical microscopy of the drops and spectrophotometry of the resolved aqueous phase allowed us to estimate the interfacial adsorption densities of the particles using the phenomenon of limited coalescence. We deduce two classes of particle arrangement. Complete adsorption of the particles was obtained when they were neutral or when their charges were screened by salt resulting in at least one particle monolayer at the interface. By contrast, only around 50% of the particles adsorbed when they were charged with emulsion drops being covered by less than half a monolayer. These findings were supported by direct visualization of drop interfaces using cryo-scanning electron microscopy. Uncharged particles were highly aggregated and formed a continuous 2-D network at the interface. Otherwise particles organized as individual aggregates separated by particle-free regions. In this case, we suggest that some particles spread at the interface leading to the formation of a continuous protein membrane. Charged particles displayed the ability to bridge opposing interfaces of neighbouring drops to form dense particle disks protecting drops against coalescence; this is the main reason for the flocculation and stability of emulsions containing sparsely covered drops. © 2014 the Partner Organisations

Giant Collective Spin-Orbit Field in a Quantum Well: Fine Structure of Spin Plasmons

We employ inelastic light scattering with magnetic fields to study intersubband spin plasmons in a quantum well. We demonstrate the existence of a giant collective spin-orbit (SO) field that splits the spin-plasmon spectrum into a triplet. The effect is remarkable as each individual electron would be expected to precess in its own momentum-dependent SO field, leading to D'yakonov-Perel' dephasing. Instead, many-body effects lead to a striking organization of the SO fields at the collective level. The macroscopic spin moment is quantized by a uniform collective SO field, five times higher than the individual SO field. We provide a momentum-space cartography of this field.Comment: 5 pages, 4 figures. Supplemental material available here as an ancillary fil

Heart rate sensors acceptability: data reliability vs. ease of use

International audienceIn the present study we focused on heart rate sensors and compared the acceptability and usability of the various devices candidates to feed the PRECIOUS (PREventive Care Infrastructure based On Ubiquitous Sensing) system. More precisely, smart-watch, chest-belt and 2-points-electrodes have been tested by users during 24 hours. Each device test lead to consult lifestyle reports about stress, sleep and physical activity. During this experimentation 11 participants completed different acceptability questionnaires. The first results interpretation revealed which sensor is the most acceptable and gave insight into how data reliability of the different devices influenced their respective acceptability in the daily life