dollhouse: An Exhibition of Installation

"dollhouse" is a dreamy, peachy, pretty little private space saturated with sickly sweetness. The installation consists of three rooms built inside the shell of a 1971 Airstream trailer, filled with objects, forms, and colors associated with conventional femininity. As a whole, "dollhouse" simultaneously asserts the value of this so-called “feminine” affinity for embellishment and color, and questions the ideals, assumptions, and expectations through which women and girls are jointly framed and perceived by society. In order to illuminate some of the theoretical and conceptual underpinnings of the work, this paper explores dollhouse through five interrelated sections: ambivalence, hyperfemininity, artifice, beauty, and sexuality

Spatiotemporal and Wavenumber Resolved Bicoherence at the Low to High Confinement Transition in the TJ-II Stellarator

Plasma turbulence is studied using Doppler reflectometry at the TJ-II stellarator. By scanning the tilt angle of the probing beam, different values of the perpendicular wave numbers are probed at the reflection layer. In this way, the interaction between zonal flows and turbulence is reported with (a) spatial, (b) temporal, and (c) wavenumber resolution for the first time in any magnetic confinement fusion device. We report measurements of the bicoherence across the Low to High (L--H) confinement transition at TJ-II. We examine both fast transitions and slow transitions characterized by an intermediate (I) phase. The bicoherence, understood to reflect the non-linear coupling between the perpendicular velocity (zonal flow) and turbulence amplitude, is significantly enhanced in a time window of several tens of ms around the time of the L--H transition. It is found to peak at a specific radial position (slightly inward from the radial electric field shear layer in H mode), and is associated with a specific perpendicular wave number ($k_\perp \simeq 6-12$ cm$^{-1}$, $k_\perp \rho_s \simeq 0.8-2$). In all cases, the bicoherence is due to the interaction between high frequencies ($\simeq 1$ MHz) and a rather low frequency ($\lesssim 50$ kHz), as expected for a zonal flow.Comment: 11 pages, 3 figure

Continuous Time Random Walks in periodic systems: fluid limit and fractional differential equations on the circle

In this article, the continuous time random walk on the circle is studied. We derive the corresponding generalized master equation and discuss the effects of topology, especially important when Levy flights are allowed. Then, we work out the fluid limit equation, formulated in terms of the periodic version of the fractional Riemann-Liouville operators, for which we provide explicit expressions. Finally, we compute the propagator in some simple cases. The analysis presented herein should be relevant when investigating anomalous transport phenomena in systems with periodic dimensions.Comment: 14 pages, 1 figure. References added. Published versio

Causality detection and turbulence in fusion plasmas

This work explores the potential of an information-theoretical causality detection method for unraveling the relation between fluctuating variables in complex nonlinear systems. The method is tested on some simple though nonlinear models, and guidelines for the choice of analysis parameters are established. Then, measurements from magnetically confined fusion plasmas are analyzed. The selected data bear relevance to the all-important spontaneous confinement transitions often observed in fusion plasmas, fundamental for the design of an economically attractive fusion reactor. It is shown how the present method is capable of clarifying the interaction between fluctuating quantities such as the turbulence amplitude, turbulent flux, and Zonal Flow amplitude, and uncovers several interactions that were missed by traditional methods.Comment: 26 pages, 14 figure

Analytical model for tracer dispersion in porous media

In this work, we present a novel analytical model for tracer dispersion in laminar flow through porous media. Based on a straightforward physical argument, it describes the generic behavior of dispersion over a wide range of Peclet numbers (exceeding 8 orders of magnitude). In particular, the model accurately captures the intermediate scaling behavior of longitudinal dispersion, obviating the need to subdivide the dispersional behavior into a number of disjunct regimes or using empirical power law expressions. The analysis also reveals the existence of a new material property, the critical Peclet number, which reflects the mesoscale geometric properties of the microscopic pore structure.Comment: 13 pages, 4 figure

Fick's law and Fokker-Planck Equation in inhomogeneous environments

In inhomogeneous environments, the correct expression of the diffusive flux is often not given by the Fick's law $\Gamma = - D \nabla n$. The most general hydrodynamic equation modelling diffusion is indeed the Fokker-Planck Equation (FPE). The microscopic dynamics of each specific system may affect the form of the FPE, either establishing connections between the diffusion and the convection term, as well as providing supplementary terms. In particular, the Fick's form for the Diffusion Equation may arise only in consequence of a specific kind of microscopic dynamics. It is also shown how, in the presence of sharp inhomogeneities, even the hydrodynamic FPE limit may becomes inaccurate and mask some features of the true solution, as computed from the Master Equation.Comment: V2: English amended. V3: final version accepted by Physics Letters