Dynamics of the spontaneous breakdown of superhydrophobicity

Drops deposited on rough and hydrophobic surfaces can stay suspended with gas pockets underneath the liquid, then showing very low hydrodynamic resistance. When this superhydrophobic state breaks down, the subsequent wetting process can show different dynamical properties. A suitable choice of the geometry can make the wetting front propagate in a stepwise manner leading to {\it square-shaped} wetted area: the front propagation is slow and the patterned surface fills by rows through a {\it zipping} mechanism. The multiple time scale scenario of this wetting process is experimentally characterized and compared to numerical simulations.Comment: 7 pages, 5 figure

Experimental Signature of Medium Modifications for rho and omega Mesons in the 12 GeV p + A Reactions

The invariant mass spectra of e+e- pairs produced in 12-GeV proton-induced nuclear reactions are measured at the KEK Proton-Synchrotron. On the low-mass side of the omega meson peak, a significant enhancement over the known hadronic sources has been observed. The mass spectra, including the excess, are well reproduced by a model that takes into account the density dependence of the vector meson mass modification, as theoretically predicted.Comment: 4 pages, 3 figures, Version accepted for Physical Review Lette

Intersecting black branes in strong gravitational waves

We consider intersecting black branes with strong gravitational waves propagating along their worldvolume in the context of supergravity theories. Both near-horizon and space-filling gravitational wave modes are included in our ansatz. The equations of motion (originally, partial differential equations) are shown to reduce to ordinary differential equations, which include a Toda-like system. For special arrangements of intersecting black branes, the Toda-like system becomes integrable, permitting a more thorough analysis of the gravitational equations of motion.Comment: 17 pages; v2: cosmetic improvements, published versio

Development of a CMOS SOI pixel detector

We have developed a monolithic radiation pixel detector using silicon on insulator (SOI) with a commercial 0.15 m fullydepleted- SOI technology and a Czochralski high resistivity silicon substrate in place of a handle wafer. The SOI TEG (Test Element Group) chips with a size of 2.5 x 2.5mm2 consisting of 20 x 20 um2 pixels have been designed and manufactured. Performance tests with a laser light illumination and a . ray radioactive source indicate successful operation of the detector. We also brie y discuss the back gate effect as well as the simulation study

Supersymmetric Intersecting Branes on the Waves

We construct a general family of supersymmetric solutions in time- and space-dependent wave backgrounds in general supergravity theories describing single and intersecting p-branes embedded into time-dependent dilaton-gravity plane waves of an arbitrary (isotropic) profile, with the brane world-volume aligned parallel to the propagation direction of the wave. We discuss how many degrees of freedom we have in the solutions. We also propose that these solutions can be used to describe higher-dimensional time-dependent "black holes", and discuss their property briefly.Comment: 12 pages, LaTe