We have completed a systematic survey for disks around young brown dwarfs and very low mass stars. By choosing a well-defined sample and by obtaining sensitive thermal IR observations, we can make an unbiased measurement of the disk fraction around such low mass objects. We find that ≈75% of our sample show intrinsic IR excesses, indicative of circum(sub)stellar disks. We discuss the physical p...

Quinoxaline cavitands (QxCav) are transferred by Langmuir-Schaefer method on self-assembled monolayers (SAMs) of octadecyltrichlorosilane (OTS) and N,N-dimethyl-N-octadecyl-3-aminopropyltrimethoxysilyl chloride (DMOAP) on fused silica substrates. The molecular architectures of both the hydrophobic SAMs templates and the hybrid cavitand-organosilanes bilayers at the solid-air interface are inves...

We consider the problem of identifying n points in the plane using disks, i.e., minimizing the number of disks so that each point is contained in a disk and no two points are in exactly the same set of disks. This problem can be seen as an instance of the test covering problem with geometric constraints on the tests. We give tight lower and upper bounds on the number of disks needed to identify...

MZR(Multi-Zone Recording) disks are widely used for their high overall bandwidth and capacity nowadays. Since MZR disks show different bandwidths and capacities depending on the zone, data placement schemes for traditional CAD(Constant Angular Density) disks are not suitable for MZR disks. Especially, since the performance of continuous media servers strongly depend on the block placement schem...

Papaya (Carica papaya L.) pulp tissue disks in an incubation medium composed of 0.4 m sucrose evolve ethylene at an optimum pH of 5.25 at 30 C. Disks of young preclimacteric fruit evolve the gas linearly with fruit age until fruit age reaches 4 months. Disks from 5-month-old postclimacteric fruit produce approximately 5-fold more ethylene than disks from 4-month-old fruit. Ethylene evolution by...

We present some results from a systematic survey for disks around spectroscopically identified young brown dwarfs and very low mass stars. We find that ≈75% of our sample show intrinsic IR excesses, indicative of circum(sub)stellar disks. The observed excesses are well-correlated with Hα emission, consistent with a common disk accretion origin. Because the excesses are modest, conventional anal...

We have searched six stars with known radial velocity planetary companions for circumstellar disks. Disks are expected around stars with planetary systems that accreted from regular protoplanetary disks, and remnant disks are expected to be similar to our solar systemÏs Kuiper Belt. To date, we have detected circumstellar disks around three such stars : 55 Cnc, o CrB, and HD 210277. All these s...

Duschl et al. (2000) have shown that the standard model for geometrically thin accretion disks (α-disks) leads to inconsistency if self-gravity play a role. This problem arise from parametrization of viscosity in terms of local sound velocity and vertical disks scale hight. The β-viscosity prescription was introduced by Duschl et al. (2000), which has been derived from rotating shear flow exper...

Abstract We provide a tight result for fundamental problem arising from packing disks into circular container: The critical density of in disk is 0.5. This implies that any set (not necessarily equal) total area $$\delta \le 1/2$$ ? ? 1 / 2 </...

We show that accretion disks in several compact X-ray binaries with hydrogen– depleted donors are likely subject to a thermal ionization instability, unless they are strongly irradiated. These disks are particularly interesting in that their MHDturbulent properties in the neutral phase may be quite different from those of standard, hydrogen–rich disks. subject headings: X-ray: stars – accretion...