A thermodynamical model for non-extremal black p-brane

We show that the correct entropy, temperature (and absorption probability) of non-extremal black p-brane can be reproduced by a certain thermodynamical model when maximizing its entropy. We show that the form of the model is related to the geometrical similarity of non-extremal and near extremal black p-brane at near horizon region, and argue about the appropriateness of the model.Comment: Almost the same version as the paper appeared in Physical Review

Reconstruction of the Structure of Accretion Disks in Dwarf Novae from the Multi-Band Light Curves of Early Superhumps

We propose a new method to reconstruct the structure of accretion disks in dwarf novae using multi-band light curves of early superhumps. Our model assumes that early superhumps are caused by the rotation effect of non-axisymmetrically flaring disks. We have developed a Bayesian model for this reconstruction, in which a smoother disk-structure tends to have a higher prior probability. We analyzed simultaneous optical and near-infrared photometric data of early superhumps of the dwarf nova, V455 And using this technique. The reconstructed disk has two flaring parts in the outermost region of the disk. These parts are responsible for the primary and secondary maxima of the light curves. The height-to-radius ratio is h/r=0.20-0.25 in the outermost region. In addition to the outermost flaring structures, flaring arm-like patterns can be seen in an inner region of the reconstructed disk. The overall profile of the reconstructed disk is reminiscent of the disk structure that is deformed by the tidal effect. However, an inner arm-like pattern, which is responsible for the secondary minimum in the light curve, cannot be reproduced only by the tidal effect. It implies the presence of another mechanism that deforms the disk structure. Alternatively, the temperature distribution of the disk could be non-axisymmetric. We demonstrate that the disk structure with weaker arm-like patterns is optimal in the model including the irradiation effect. However, the strongly irradiated disk gives quite blue colors, which may conflict with the observation. Our results suggest that the amplitude of early superhumps depends mainly on the height of the outermost flaring regions of the disk. We predict that early superhumps can be detected with an amplitude of >0.02 mag in about 90% of WZ Sge stars.Comment: 17 pages, 17 figures, accepted for publication in PAS

The renormalized jellium model for spherical and cylindrical colloids

Starting from a mean-field description for a dispersion of highly charged spherical or (parallel) rod-like colloids, we introduce the simplification of a homogeneous background to include the contribution of other polyions to the static field created by a tagged polyion. The charge of this background is self-consistently renormalized to coincide with the polyion effective charge, the latter quantity thereby exhibiting a non-trivial density dependence, which directly enters into the equation of state through a simple analytical expression. The good agreement observed between the pressure calculated using the renormalized jellium and Monte Carlo simulations confirms the relevance of the {renormalized} jellium model for theoretical and experimental purposes and provides an alternative to the Poisson-Boltzmann cell model since it is free of some of the intrinsic limitations of this approach

Effect of Soil Dilatancy on Vibration and Earth Pressure

A model ground of air dried sand compacted in a shear testing apparatus and two composite models each of which have the model pit of different rigidity buried in a same model ground as above one are excited horizontally with sinusoidal motions on a shaking table. From measured accelerations and dynamic earth pressure it is found that the vertical vibration is produced in the ground due to the dilatancy or volume change of soil and yet it produces the dynamic earth pressure acting horizontally on all outside walls of the model pit. In order to simulate the results of tests three dimensional finite element procedure with elasto-plastic dynamic response analysis is used. Good agreement between the tests results and predictions is obtained

Blocks at Your Fingertips: Blurring the Line Between Blocks and Text in GP

Visual blocks languages offer many advantages to the beginner or “casual” programmer. They eliminate syntax issues, allow the user to work with logical program chunks, provide affordances such as drop-down menus, and leverage the fact that recognition is easier than recall. However, as users gain experience and start creating larger programs, they encounter two inconvenient properties of pure blocks languages: blocks take up more screen real-estate than textual languages and dragging blocks from a palette is slower than typing. This paper describes three experiments in blurring the line between blocks and textual code in GP, a new blocks language for casual programmers currently under development