Winds from massive stars supply ≈ 10 −3 M ⊙ yr −1 of gas to the central parsec of the Galactic Center. Spherically symmetric hydrodynamic calculations show that ≈ 1% of this gas, or ≈ 10 −5 M ⊙ yr −1 , flows in towards the central massive black hole Sgr A*; the remaining gas, ≈ 10 −3 M ⊙ yr −1 , is thermally driven out of the central star cluster in a wind. This dynamical model accounts for the...

the effect of grain size, tailwater depth and grain froude number on local scour caused by submerged horizontal jets issuing below a sluice gate was investigated. noncohesive sediments with two gradations downstream of a horizontal apron were used in the experiments. the experiments were carried out at different inflow froude numbers and a range of tailwater depth from low to high submergence. ...

The concept of p-channel InGaN/GaN heterostructure field effect transistor (FET) using a two-dimensional hole gas (2DHG) induced by polarization effect is demonstrated. The existence of 2DHG near the lower interface of InGaN/GaN heterostructure is verified by theoretical simulation and capacitance-voltage profiling. The metal-oxide-semiconductor FET (MOSFET) with Al2O3 gate dielectric shows a d...

We present transport experiments performed in high-quality quantum point contacts embedded in a GaAs two-dimensional hole gas. The strong spin-orbit interaction results in peculiar transport phenomena, including the previously observed anisotropic Zeeman splitting and level-dependent effective g factors. Here we find additional effects, namely, the crossing and the anticrossing of spin-split le...

Banks, Fischler, Klebanov and Susskind have proposed a model for black hole thermodynamics based on the principle that the entropy is of order the number of particles at the phase transition point in a Boltzmann gas of D0-branes. We show that the deviations from Boltzmann scaling found in d<6 noncompact spatial dimensions have a simple explanation in the analysis of self-gravitating random walk...

We investigate two-dimensional dilaton gravity models with a power-law dilaton potential, whose black hole solutions contain, among others, the dimensional reduction of the Schwarzschild black hole, the Anti-de Sitter black hole and Rindler spacetime. We show that the ground state of these models satisfies simple transformation laws under the SL(2, R) conformal group. We use these transformatio...

We describe three-dimensional general relativistic magnetohydrodynamic simulations of a geometrically thin accretion disk around a non-spinning black hole. The disk has a thickness h/r ∼ 0.05−0.1 over the radius range (2−20)GM/c2. In steady state, the specific angular momentum profile of the inflowing magnetized gas deviates by less than 2% from that of the standard thin disk model of Novikov &...

This Letter reports on 3-dimensional simulations of Kerr black hole magnetospheres that obey the general relativistic equations of perfect magnetohydrodynamics (MHD). In particular, we study powerful Poynting flux dominated jets that are driven from dense gas in the equatorial plane in the ergosphere. The physics of which has been previously studied in the simplified limit of an ergopsheric dis...

We study gravitationally collapsing models of pressureless dust, fluids with pressure, and the generalized Chaplygin gas (GCG) shell in (2+1)-dimensional spacetimes. Various collapse scenarios are investigated under a variety of the background configurations such as anti-de Sitter(AdS) black hole, de Sitter (dS) space, flat and AdS space with a conical deficit. As with the case of a disk of dus...

The observed properties of supermassive black holes suggest a fundamental link between their assembly and the formation of their host spheroids. We model the growth and activity of black holes in galaxies using ΛCDM cosmological hydrodynamic simulations by following the evolution of the baryonic mass component in galaxy potential wells. We find that the observed steep relation between black hol...