Class D spaces admitting an electromagnetic field
Expanding solutions of Einstein-Maxwell equations in D class spaces admitting null and nonnull electromagnetic field
Cahen, M.↗
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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Brewster angle of the lunar crust.
Brewster null in reflections of Explorer 35 telemetry transmissions from lunar surface, discussing radiation reflection properties of lunar maria and Flamsteed area
Tyler, G. L.↗
The signal-to-noise ratio estimation techniques for PCM signals.
Spectral null from spectral characteristics and statistical properties of PCM signals used to estimate SNR
Sos, J. Y.↗
Irregular regions in the antarctic ionosphere.
Irregular regions in Antarctic ionosphere from Polar Ionosphere Beacon Satellite S-66 recordings, obtaining irregularities density from nulls clarity
Stuart, G. F.↗
Shop-testing a 107-inch telescope mirror.
Test methods for telescope mirror, discussing polishing, monitoring by Hartmann test and visual null test
Tull, R. G.↗
Degenerate gravitational fields with twisting rays.
Einstein equations for empty space applied to degenerate gravitational fields with twisting rays, admitting shear-free twisting congruence of null geodesics
Robinson, I.↗
The space research centrifuge design and evolution of experiments.
Space research centrifuge counteracting null gravity physiological deconditioning, discussing linear and angular accelerations sensitivity and deconditioning effect on reentry task performance
Newsom, B. D.↗
Radiation from a circularly polarized antenna through the ionized wake of a Mars-entry capsule.
Mars entry capsule ionized wake producing circularly polarized antenna radiation null region, noting effect on communication blackout time
Ishimaru, A.↗
Fluidic accelerometer
Fluidic accelerometer utilizing seismic mass nulled by feedback loop and independent of supply pressure variations
Ringwall, C. G.↗
Theory of time-varying spectral analysis and complex Wishart matrix processes
Distributional results pertaining to complex Wishart processes and time varying spectral estimators on null hypothesis of stationary Gaussian time series
Dubman, M. R.↗
Vacuum metrices without symmetry
Vacuum metrics with null geodetic expanding shear- free congruences using holomorphic solution
Robinson, I.↗
Magnetic-field re-connexion in a highly conducting incompressible fluid
Model for magnetic field-line reconnection in conducting incompressible fluid, determining maximum reconnection rate entirely by null point conditions
Sonnerup, B. U. OE.↗
Small size transformer provides high power regulation with low ripple and maximum control
Single, variable, transformer/choke device does work of several. Technique reduces drawer assembly physical size and design and manufacturing cost. Device provides power, voltage current and impedance regulation while maintaining maximum control of linearity and ensuring extremely low ripple. Nulling is controlled to very fine degree.
Manoli, R.↗
Pulse width-pulse rate modulator
Attitude control system designed for rockets regulates duty cycle of pneumatic valves so less fuel is required. Operation time of each valve is directly proportional to error signal and the dead band about a null is controlled by independently adjustable threshold circuits.
Cooke, W. A.↗
Transistor servo system including a unique differential amplifier circuit Patent
Electric motor control system with pulse width modulation for providing automatic null seeking servo
Currie, J. R.↗
Interferometric rotation sensor
Sensor generates interference fringes varying in number (horizontally and vertically) as a function of the total angular deviation relative to the line-of-sight axis. Device eliminates errors from zero or null shift due to lack of electrical circuitry stability.
Walsh, T. M.↗
Development of techniques for measuring pilot workload
An objective method of assessing information workload based on physiological measurements was developed. Information workload, or reserve capacity, was measured using a visual discrimination secondary task and subjective rating of task difficulty. The primary task was two axis (pitch and roll) tracking, and the independent variables in this study were aircraft pitch dynamics and wind gust disturbances. The study was structured to provide: (1) a sensitive, nonloading measure of reserve capacity, and (2) an unencumbering reliable measurement of the psychophysiological state. From these, a measured workload index (MWI) and physiological workload index (PWI) were extracted. An important measure of the success of this study was the degree to which the MWI and PWI agreed across the 243 randomly-presented, four-minute trials (9 subjects X 9 tasks X 3 replications). The electrophysiological data collected included vectorcardiogaram, respiration, electromyogram, skin impedance, and electroencephalogram. Special computer programs were created for the analysis of each physiological variable. The digital data base then consisted of 82 physiological features for each of the 243 trials. A prediction of workload based on physiological observations was formulated as a simultaneous least-squares prediction problem. A best subset of 10 features was chosen to predict the three measures of reserve capacity. The cannonical correlation coefficient was .754 with a chi squared value of 91.3 which allows rejection of the null hypothesis with p of .995.
Spyker, D. A.↗
Development of a satellite microwave radiometer to sense the surface temperature of the world oceans
A proposed S-band radiometer for determining the ocean surface temperature with an absolute accuracy of + or - 1 Kelvin and a resolution of + or - .1 Kelvin was placed under the Advanced Applications Flight Experiment for further development into Nimbus readiness state. The results of assessing the following are described: effects due to the state of the sea surface, effects caused by the intervening atmosphere, and effects associated with imperfections in the instrument itself. An extensive sea truth program is also described for correlation of aircraft test flight measurements or of satellite remote measurement to in-situ data. An improved radiometer design is a modified Dicke-switch type with temperature stabilized, microwave integrated circuit, front-end and with a pulsed injection-noise nulling system. The radiometer has a multimode rectangular horn antenna with very low ohmic losses and a beam efficiency of 98% or better.
Hidy, G. M.↗