8,523 research outputs found
Temperature telemetric transmitter Patent
Temperature telemetric transmitter with frequency determining tank circuit for short range transmissio
A pressure telemeter for wind-tunnel free-flight pressure measurement
Design and performance characteristics of pressure telemeter for use on scale models in free flight in hypersonic wind tunne
Automation and robotics considerations for a lunar base
An envisioned lunar outpost shares with other NASA missions many of the same criteria that have prompted the development of intelligent automation techniques with NASA. Because of increased radiation hazards, crew surface activities will probably be even more restricted than current extravehicular activity in low Earth orbit. Crew availability for routine and repetitive tasks will be at least as limited as that envisioned for the space station, particularly in the early phases of lunar development. Certain tasks are better suited to the untiring watchfulness of computers, such as the monitoring and diagnosis of multiple complex systems, and the perception and analysis of slowly developing faults in such systems. In addition, mounting costs and constrained budgets require that human resource requirements for ground control be minimized. This paper provides a glimpse of certain lunar base tasks as seen through the lens of automation and robotic (A&R) considerations. This can allow a more efficient focusing of research and development not only in A&R, but also in those technologies that will depend on A&R in the lunar environment
Rocket calibration of the Nimbus 6 solar constant measurements
Total solar irradiance was observed simultaneously outside the earth's atmosphere by three types of absolute cavity radiometers and duplicates of four of the Nimbus 6 Earth Radiation Budget (ERB) solar channels in a June 1976 sounding rocket experiment. The preliminary average solar constant result from the cavity radiometers is 1367 Wm (-2) with an uncertainty of less than + or - 0.5% in S.I. units. The duplicate ERB channel 3 on the rocket gave a value of 1389 Wm (-2) which agreed exactly with the Nimbus 6 ERB channel 3 measurement made simultaneously with the rocket flight
(In)finiteness of Spherically Symmetric Static Perfect Fluids
This work is concerned with the finiteness problem for static, spherically
symmetric perfect fluids in both Newtonian Gravity and General Relativity. We
derive criteria on the barotropic equation of state guaranteeing that the
corresponding perfect fluid solutions possess finite/infinite extent. In the
Newtonian case, for the large class of monotonic equations of state, and in
General Relativity we improve earlier results
Admission to the Bar: A Constitutional Analysis
This Special Project examines and analyzes selected constitutional challenges to requirements for permanent and temporary admission to the bar. In the area of permanent admission, the Special Project looks at constitutional challenges to three qualifications typically required of bar applicants by states: demonstration of good moral character, successful completion of a bar examination, and residency. In the area of admission pro hac vice , the Project examines constitutional challenges to the basis on which judges have denied temporary admission to an applicant
Superconducting p-branes and Extremal Black Holes
In Einstein-Maxwell theory, magnetic flux lines are `expelled' from a black
hole as extremality is approached, in the sense that the component of the field
strength normal to the horizon goes to zero. Thus, extremal black holes are
found to exhibit the sort of `Meissner effect' which is characteristic of
superconducting media. We review some of the evidence for this effect, and do
present new evidence for it using recently found black hole solutions in string
theory and Kaluza-Klein theory. We also present some new solutions, which arise
naturally in string theory, which are non-superconducting extremal black holes.
We present a nice geometrical interpretation of these effects derived by
looking carefully at the higher dimensional configurations from which the lower
dimensional black hole solutions are obtained. We show that other extremal
solitonic objects in string theory (such as p-branes) can also display
superconducting properties. In particular, we argue that the relativistic
London equation will hold on the worldvolume of `light' superconducting
p-branes (which are embedded in flat space), and that minimally coupled zero
modes will propagate in the adS factor of the near-horizon geometries of
`heavy', or gravitating, superconducting p-branes.Comment: 22 pages, 2 figure
- …