An automated stall-speed warning system

The development and testing of a stall-speed warning system for the OV-1C was examined. NASA designed and built an automated stall-speed warning system which presents both airspeed and stall speed to the pilot. The airspeed and stall speed are computed in real time by monitoring the basic aerodynamic parameters (dynamic pressure, horizontal and vertical accelerations, and pressure altitude) and other parameters (elevator and flap positions, engine torques, and fuel flow). In addition, an aural warning at predetermined stall margins is presented to the pilot through a voice synthesizer. Once the system was designed and installed in the aircraft, a flight-test program of less than 20 hrs was anticipated to determine the stall-speed software coefficients. These coefficients would then be inserted in the system's software and then test flown over a period of about 10 hr for the purpose of evaluation

The Structure of the DoAr 25 Circumstellar Disk

We present high spatial resolution (< 0.3" = 40$AU) Submillimeter Array observations of the 865 micron continuum emission from the circumstellar disk around the young star DoAr 25. Despite its bright millimeter emission, this source exhibits only a comparatively small infrared excess and low accretion rate, suggesting that the material and structural properties of the inner disk may be in an advanced state of evolution. A simple model of the physical conditions in the disk is derived from the submillimeter visibilities and the complete spectral energy distribution using a Monte Carlo radiative transfer code. For the standard assumption of a homogeneous grain size distribution at all disk radii, the results indicate a shallow surface density profile,$\Sigma \propto r^{-p}$ with p = 0.34, significantly less steep than a steady-state accretion disk (p = 1) or the often adopted minimum mass solar nebula (p = 1.5). Even though the total mass of material is large (M_d = 0.10 M_sun), the densities inferred in the inner disk for such a model may be too low to facilitate any mode of planet formation. However, alternative models with steeper density gradients (p = 1) can explain the observations equally well if substantial grain growth in the planet formation region (r < 40 AU) has occurred. We discuss these data in the context of such models with dust properties that vary with radius and highlight their implications for understanding disk evolution and the early stages of planet formation.Comment: ApJL in pres

Justice at the Margins: Equitable Tolling of Washington\u27s Deadline for Filing Collateral Attacks on Criminal Judgments

RCW 10.73.090 establishes a one-year deadline for appealing a final criminal judgment in Washington State. This Comment argues that this one-year deadline should be subject to the doctrine of equitable tolling, which can prevent a statute of limitation from expiring when extraordinary circumstances preclude timely filing. After examining the text, legislative history, structure, purpose, and policy implications of RCW 10.73.090, this Comment demonstrates that the one-year deadline does not operate as a jurisdictional bar, which would revoke judicial power to hear a postconviction appeal after one year under any circumstances, but instead acts as a statute of limitation subject to equitable tolling. This Comment also argues that the filing deadline should be subject to equitable tolling because the overwhelming majority of federal circuit courts to consider the issue have reached the similar conclusion that the one-year limitation for filing federal habeas corpus petitions can be equitably tolled

Electrolytically regenerative hydrogen-oxygen fuel cell Patent

Electrolytically regenerative hydrogen-oxygen fuel cell

The effect of local optically thick regions in the long-wave emission of young circumstellar disks

Multi-wavelength observations of protoplanetary disks in the sub-millimeter continuum have measured spectral indices values which are significantly lower than what is found in the diffuse interstellar medium. Under the assumption that mm-wave emission of disks is mostly optically thin, these data have been generally interpreted as evidence for the presence of mm/cm-sized pebbles in the disk outer regions. In this work we investigate the effect of possible local optically thick regions on the mm-wave emission of protoplanetary disks without mm/cm-sized grains. A significant local increase of the optical depth in the disk can be caused by the concentration of solid particles, as predicted to result from a variety of proposed physical mechanisms. We calculate the filling factors and implied overdensities these optically thick regions would need to significantly affect the millimeter fluxes of disks, and we discuss their plausibility. We find that optically thick regions characterized by relatively small filling factors can reproduce the mm-data of young disks without requesting emission from mm/cm-sized pebbles. However, these optically thick regions require dust overdensities much larger than what predicted by any of the physical processes proposed in the literature to drive the concentration of solids. We find that only for the most massive disks it is possible and plausible to imagine that the presence of optically thick regions in the disk is responsible for the low measured values of the mm spectral index. For the majority of the disk population, optically thin emission from a population of large mm-sized grains remains the most plausible explanation. The results of this analysis further strengthen the scenario for which the measured low spectral indices of protoplanetary disks at mm wavelengths are due to the presence of large mm/cm-sized pebbles in the disk outer regions.Comment: 13 pages, 2 figures, A&A in pres