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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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Thin carbon film deposited on a 70 percent transparent screen provides a filter for narrow-band detectors in the extreme ultraviolet. The filter also suppresses scattered light and light of unwanted orders in vacuum spectrographs.
Miniaturized bandpass filter with RC networks is suitable for use in integrated circuits. The circuit consists of three stages of amplification with additional resistive and capacitive components to obtain the desired characteristics. The advantages of the active RC filter network are the reduction in size and weight and elimination of magnetic materials.
Filtered samples of molten metals are obtained by filtering through a plug of porous material fitted in the end of a sample tube, and unfiltered samples are obtained by using a capillary-tube extension rod with a perforated bucket. With these methods there are no sampling errors or loss of liquid.
Digital filter synthesis computer program expresses any continuous function of a complex variable in approximate form as a computational algorithm or difference equation. Once the difference equation has been developed, digital filtering can be performed by the program on any input data list.
Set of design curves eliminates work involved in designing linear phase filters by being normalized in such a way as to apply to low, band, and high-pass filters of any bandwidth. Similar curves for any number of poles are plotted by solving a system of simultaneous equations.
Low pass filter, bandpass filter, and design of input system for speech recognition computer
Linearly filtered angle modulated signals distortion and crosstalk analysis applied to filter input-output relation, noting satellite communication FM reception
Optimal linear filter derivation using Pontryagin maximum principle and gradient matrices for optimal filter coefficients
Limited memory optimal filter theory, output and standard filter divergence due to errors
Transmission measurement of neutrons by filter materials for low energy neutrons is important for the study of structure and dynamics of condensed matter. Since only thermal neutrons are useful for such experiments, filter materials that transmit thermal neutrons while attenuating fast neutrons and gamma rays are of considerable interest.
Range switching digital filter with three predetermined quantization levels decreases quantization deadband. Mathematical program form implements the transfer function of the filter.
Generalized digital filter is a special purpose computer. The term digital filter is an algorithm which accepts an input sequence of numbers and transforms it into an output number sequence. The organization of the computer, the logical design and synthesis, and experimentaion with the computer in two sampled data control systems is discussed.
Narrow band optical filter is electronically tunable over a large wavelength region. The filter utilizes collinear acousto-optic diffraction in an optically anisotropic media.
Blocking filter effects on long-wavelength rejection of ultraviolet bandpass filter
Limited memory optimal filter theory, output and standard filter divergence due to errors
Adaptive filtering to prevent divergence observed in application of Kalman filter to orbit determination
Adaptive filter for estimating system noise inputs from actual residuals developed to control Kalman filter in satellite orbit estimation
Filtering optimization prior to limiting digital signals in strong noise, detailing bandwidth choice of single pole low pass filter