71,516 research outputs found
Results from the National Aeronautics and Space Administration remote sensing experiments in the New York Bight, 7-17 April 1975
A cooperative operation was conducted in the New York Bight to evaluate the role of remote sensing technology to monitor ocean dumping. Six NASA remote sensing experiments were flown on the C-54, U-2, and C-130 NASA aircraft, while NOAA obtained concurrent sea truth information using helicopters and surface platforms. The experiments included: (1) a Radiometer/Scatterometer (RADSCAT), (2) an Ocean Color Scanner (OCS), (3) a Multichannel Ocean Color Sensor (MOCS), (4) four Hasselblad cameras, (5) an Ebert spectrometer; and (6) a Reconafax IV infrared scanner and a Precision Radiation Thermometer (PRT-5). The results of these experiments relative to the use of remote sensors to detect, quantify, and determine the dispersion of pollutants dumped into the New York Bight are presented
High-temperature LM cathode ion thrusters Quarterly progress report, 5 May - 4 Aug. 1968
Design and operation of high temperature liquid mercury cathode ion thruster
An outlook for cargo aircraft of the future
An assessment is provided of the future of air cargo by analyzing air cargo statistics and trends, by noting air cargo system problems and inefficiencies, by analyzing characteristics of air-eligible commodities, and by showing the promise of new technology for future cargo aircraft with significant improvements in costs and efficiency. NASA's proposed program is reviewed which would sponsor the research needed to provide for development of advanced designs by 1985
Development of a rotary fluid transfer coupling and support mechanism for space station
A design was developed for a rotary fluid coupling to transfer coolant fluids (primarily anhydrous ammonia) across rotating joints of the space station. Development testing using three conceptual designs yielded data which were used to establish the design of a multipass fluid coupling capable of handling three fluid circuits. In addition, a mechanism to support the fluid coupling and allow an astronaut to replace the coupling quickly and easily was designed
Hartree-Fock calculations for the ground and first excited states of H2
Hartree-Fock calculation for ground and first excited state of H
Electron-Electron Bound States in Maxwell-Chern-Simons-Proca QED3
We start from a parity-breaking MCS QED model with spontaneous breaking
of the gauge symmetry as a framework for evaluation of the electron-electron
interaction potential and for attainment of numerical values for the e-e bound
state. Three expressions are obtained for the potential according to the
polarization state of the scattered electrons. In an energy scale compatible
with Condensed Matter electronic excitations, these three potentials become
degenerated. The resulting potential is implemented in the Schrodinger equation
and the variational method is applied to carry out the electronic binding
energy. The resulting binding energies in the scale of 10-100 meV and a
correlation length in the scale of 10-30 Angs. are possible indications that
the MCS-QED model adopted may be suitable to address an eventual case of
e-e pairing in the presence of parity-symmetry breakdown. The data analyzed
here suggest an energy scale of 10-100 meV to fix the breaking of the
U(1)-symmetry.
PACS numbers: 11.10.Kk 11.15.Ex 74.20.-z 74.72.-h ICEN-PS-01/17Comment: 13 pages, style revtex, revised versio
Single-stage electrohydraulic servosystem for actuating on airflow valve with frequencies to 500 hertz
An airflow valve and its electrohydraulic actuation servosystem are described. The servosystem uses a high-power, single-stage servovalve to obtain a dynamic response beyond that of systems designed with conventional two-stage servovalves. The electrohydraulic servosystem is analyzed and the limitations imposed on system performance by such nonlinearities as signal saturations and power limitations are discussed. Descriptions of the mechanical design concepts and developmental considerations are included. Dynamic data, in the form of sweep-frequency test results, are presented and comparison with analytical results obtained with an analog computer model is made
High-temperature LM cathode ion thrusters Quarterly progress report, 5 Feb. - 4 May 1968
Poiseuille flow measurements for high temperature liquid metal cathode ion thruster
Improved design of a high response slotted plate overboard bypass valve for supersonic inlets
The electrohydraulically actuated slotted-plate bypass valve used to control the position of the normal shock during wind-tunnel investigations of supersonic inlets also has proven to be a valuable device for determining inlet dynamics and creating airflow disturbances. Operation of previous valves at high frequencies (to 100 Hz) for extended testing has resulted in numerous failures. An improved bypass-valve design is presented which increases the cyclic tolerance of the device considerably over past designs. The use of dynamic limit criteria to obtain an optimum actuator-piston size results in a frequency response which is flat within + or - 3 decibels to 120 Hz for a peak-to-peak variation of 20 percent of full area
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