Subsonic longitudinal aerodynamic characteristics of a 40 deg semiapex angle conical reentry configuration

Subsonic longitudinal aerodynamic characteristics of semiapex angle conical reentry configuratio

Space Shuttle orbiter trimmed center-of-gravity extension study

Aerodynamic, heat transfer, and system design studies to determine removable modifications for the Space Shuttle orbiter that would extend its forward center-of-gravity triom capability are summarized. Wind-tunnel tests were conducted at Mach numbers ranging from 0.25 to 20.3 to determine the most effective aerodynamic modifications. Heat transfer and system design studies determined the impact of the modifications on the thermal protection system and structural weight of the vehicle. The most effective modifications were in-fillet canards or a forward extension of the existing forward wing fillet

Flight test derived heating math models for critical locations on the orbiter during reentry

An analysis technique was developed for expanding the aerothermodynamic envelope of the Space Shuttle without subjecting the vehicle to sustained flight at more stressing heating conditions. A transient analysis program was developed to take advantage of the transient maneuvers that were flown as part of this analysis technique. Heat rates were derived from flight test data for various locations on the orbiter. The flight derived heat rates were used to update heating models based on predicted data. Future missions were then analyzed based on these flight adjusted models. A technique for comparing flight and predicted heating rate data and the extrapolation of the data to predict the aerothermodynamic environment of future missions is presented

Influence of configuration details on the subsonic characteristics of a space shuttle orbiter design

An investigation was conducted in the Langley low-turbulence pressure tunnel of a model of a space shuttle orbiter design in order to determine the influence of minor configuration geometric details on the aerodynamic characteristics at subsonic speeds. A plane wing was tested with a small planform fillet; a twisted wing was tested with both a small and a large planform fillet. Tailored attitude-control propulsion-system wing-tip and body pods, trisegmented elevons, and canopy effects were also investigated. The tests were conducted at angles of attack from -3 deg to 24 deg for sideslip angles of 0 deg and 6 deg and at a Mach number of 0.25

Review of industry-proposed in-pile thermionic space reactors. Volume I - General

Diode and reactor design and nuclear fuels including uranium carbide alloys, uranium dioxide and uranium dioxide cermets for industry proposed in-pile thermionic space reactor

ARCS, The Arcminute Radio Cluster-lens Search - I. Selection Criteria and Initial Results

We present the results of an unbiased radio search for gravitational lensing events with image separations between 15 and 60 arcsec, which would be associated with clusters of galaxies with masses >10^{13-14}M_{\sun}. A parent population of 1023 extended radio sources stronger than 35 mJy with stellar optical identifications was selected using the FIRST radio catalogue at 1.4 GHz and the APM optical catalogue. The FIRST catalogue was then searched for companions to the parent sources stronger than 7 mJy and with separation in the range 15 to 60 arcsec. Higher resolution observations of the resulting 38 lens candidates were made with the VLA at 1.4 GHz and 5 GHz, and with MERLIN at 5 GHz in order to test the lens hypothesis in each case. None of our targets was found to be a gravitational lens system. These results provide the best current constraint on the lensing rate for this angular scale, but improved calculations of lensing rates from realistic simulations of the clustering of matter on the relevant scales are required before cosmologically significant constraints can be derived from this null result. We now have an efficient, tested observational strategy with which it will be possible to make an order-of-magnitude larger unbiased search in the near future.Comment: Accepted for publication in MNRAS. 12 pages, 29 included PostScript figure

ATLAS SCT POWER SUPPLY SYSTEM

The ATLAS SCT (semiconductor tracker) comprises 2112 barrel modules mounted on four concentric barrels of length 1.5m and up to 1m diameter, and 1976 endcap modules supported by a series of 9 wheels at each end of the barrel. Each module is powered by its own independent, floating low and high voltage power supplies, referenced to ground at the detector shield. Correspondingly, each module has its own distinct cable chain all the way back to the service cavern. This presentation outlines the structure and specification of the SCT Power Supply System, including the high level control software and operational model

Ground effects related to landing of airplanes with low-aspect-ratio wings

Influence of ground induced aerodynamic effects on landing maneuver of aircraft with low aspect ratio wing

Breakdown of Strong-Coupling Perturbation Theory in Doped Mott Insulators

We show that doped Mott insulators, such as the copper-oxide superconductors, are asymptotically slaved in that the quasiparticle weight, $Z$, near half-filling depends critically on the existence of the high energy scale set by the upper Hubbard band. In particular, near half filling, the following dichotomy arises: $Z\ne 0$ when the high energy scale is integrated out but Z=0 in the thermodynamic limit when it is retained. Slavery to the high energy scale arises from quantum interference between electronic excitations across the Mott gap. Broad spectral features seen in photoemission in the normal state of the cuprates are argued to arise from high energy slavery.Comment: Published versio