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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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Reanalysis of crackle perception data using logistic and logarithmic fits and sound quality metrics
Mathematical models of human auditory perception (sound quality metrics) are explored for the purpose of fitting human subject data from a prior published study. A variety of linearizing transforms and techniques are employed. Ultimately, a model is identified that predicts 98.9% of the variance in average human subject ratings of crackliness of jet noise waveforms.
Velocity dependent Coulomb logarithm in the Landau limit of the Boltzmann equation
No abstract provided.
Multiscale Modeling of Plasmas with Small Coulomb Logarithms: Electronic Transport
We present a final report based on our research activities under grant DE-SC0019369. This report summarizes the main goals, the personnel and institutions involved, the publications that resulted and the conclusions from the research.
Effect of Logarithmically Transformed IMERG Precipitation Observations in WRF 4D-Var Data Assimilation System
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On logarithmic extrapolation of microbial survivor curves for planetary quarantine requirements.
Chemical reaction kinetics model for nonlogarithmic survival of microbial organism, comparing results with Bacillus coagulans data
High current compensation network for dc logarithmic amplifiers
Circuit voltage output is reduced by voltage equivalent to ampere resistance drop of nonlogarithmic resistances of practical diodes; therefore, output is same as circuit using ideal diode. Circuit applies to meter and electronic recorder movements, and improves performance of radiation detectors and several microbiological monitoring devices
Low cost, logarithmic mass flow computer
Computer solves the equation relating gas flow through a nozzle, venturi, or orifice to the absolute temperature, absolute pressure, and differential pressure of the fluid. Inexpensive method has high frequency response and provides true analog output.
Wide-range logarithmic radiometer for measuring high temperatures
Filter radiometer utilizing photomultiplier circuit, in which a direct-coupled amplifier varies dynode voltage to maintain constant anode current, measures rapid variations of temperature of white-hot charred body at 2000 K to 3000 K.
Micro current measuring device using plural logarithmic response heated filamentary type diodes Patent
Micromicroampere current measuring circuit, with two subminiature thermionic diodes with filament cathodes
Analysis of aircraft spectrometer data with logarithmic residuals
Spectra from airborne systems must be analyzed in terms of their mineral-related absorption features. Methods for removing backgrounds and extracting these features one at a time from reflectance spectra are discussed. Methods for converting radiance spectra into a form similar to reflectance spectra so that the feature extraction procedures can be implemented on aircraft spectrometer data are also discussed.
Two-dimensional compressible flow in centrifugal compressors with logarithmic-spiral blades
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Universal logarithmic law of velocity distribution as applied to the investigation of boundary layer and drag of streamline bodies at large Reynolds number
In the present paper we shall consider a figure of revolution, so that the formulas applicable to the more simple cases as, for example, a wing or flat plate will follow from our equations as corollaries. For checking the results of our theory, we made use of the data derived from the tests of Freeman on a 1/40-scale model of the airship "Akron" conducted in the large NACA wind tunnel. In the first part we shall derive the fundamental equation for a body of revolution according to the Karman theory in its original form, and in the second part we shall give all the comparisons of the results of tests with the modified theory.
Characterization of DBD Plasma Actuators Performance without External Flow : Thrust-Voltage Quadratic Relationship in Logarithmic Space for Sinusoidal Excitation - Part I
We present results of thrust measurements of Dielectric Barrier Discharge (DBD) plasma actuators. We have used a test setup, measurement, and data processing methodology that we developed in prior work. The tests were conducted with High Density Polyethylene (HDPE) actuators of three thicknesses. The applied voltage driving the actuators was a pure sinusoidal waveform. The test setup was suspended actuators with a partial liquid interface. The tests were conducted at low ambient humidity. The thrust was measured with an analytical balance and the results were corrected for anti-thrust to isolate the plasma generated thrust. Applying this approach resulted in smooth and repeatable data. It also enabled curve fitting that yielded quadratic relations between the plasma thrust and voltage in log-log space at constant frequencies. The results contrast power law relationships developed in literature that appear to be a rough approximation over a limited voltage range.
Characterization of DBD Plasma Actuators Performance Without External Flow - Part I: Thrust-Voltage Quadratic Relationship in Logarithmic Space for Sinusoidal Excitation
Results of characterization of Dielectric Barrier Discharge (DBD) plasma actuators without external flow are presented. The results include aerodynamic and electric performance of the actuators without external flow for different geometrical parameters, dielectric materials and applied voltage level and wave form.
Introducing a Degree of Freedom in the Family of Generalized Logarithmic Spirals
No abstract available
Logarithmic Growth of Dikes From a Depressurizing Magma Chamber
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