Results 231 to 240 of about 10,978,845 (289)
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Underwater ultra-low frequency seismic source
The Journal of the Acoustical Society of America, 2021The ultra-low frequency band (2–8 Hz) is of interest for geophysical research due to advances in the field of full waveform inversion and elastic impedance measurements. Generating sound in the ultra-low frequency range is a difficult task. A powerful source with an ultra-low frequency should be able to displace hundreds of liters of water per cycle ...
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A simple, calibrated, ultra-low frequency ballistocardiograph
Medical & Biological Engineering, 1966The physical basis of ballistocardiography has now been thoroughly investigated and there is general agreement that the ultra-low frequency system is the most satisfactory. The physiological basis of ballistocardiography and its clinical application require further study.
C K, Battye +4 more
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Ultra-low-noise regenerative frequency divider
IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control, 2012We designed ultra-low-noise regenerative divide-by- 2 circuits that operate at input frequencies of 10, 20, and 40 MHz. We achieved output-referred single-sideband residual phase noise equal to -164 dBc/Hz at 10 Hz offset and estimated residual Allan deviation, σ(y)(τ) less than 3 × 10(-15)τ(-1) for a single divider, which is, to our knowledge, the ...
Archita, Hati +5 more
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Dielectric Relaxation at Ultra Low Frequency
Ferroelectrics, 2003The isothermal charging and discharging currents were recorded for polyamide 11, polyethylene terephthalate and low density polyethylene in a large range of temperatures below and above the glass-rubber transition temperature of the amorphous phase, for different electrical fields and different charging and discharging times.
E. R. Neagu +2 more
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Ultra-low-frequency atmospherics
IRE International Convention Record, 2005The earth and the ionosphere together form a spherical-type resonant cavity. The natural frequency of this resonator was calculated by Schumann to be approximately 10 cps. In order to test this result, it was decided to determine experimentally whether or not there might actually exist in the atmosphere signals which would lie within this frequency ...
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Ultra low frequency waves in the magnetosphere
Space Science Reviews, 1970The behaviour of continuous pulsations pc 2–5 observed on the ground has been known for some time. They seldom occur at night, their amplitudes generally increase towards the auroral zones and the sense of rotation of their polarisation often agrees with surface waves on the magnetopause.
J.W. Dungey, D.J. Southwood
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Ultra low frequency precordial movements—kinetocardiograms∗
The American Journal of Cardiology, 1959K I~ETOC~RDIOGRAMS are the graphic representation of ultra low frequency displacement precordial vibrations. The frequent! components of these motions usually lie between 1 and IO cycles per second; however, Fourier analysis has revealed higher frequencies present but of less significance.
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Voltage-to-Frequency Converter for Ultra-Low-Voltage Applications
2019 42nd International Convention on Information and Communication Technology, Electronics and Microelectronics (MIPRO), 2019The paper is focused on the design and analysis of a Voltage-to-Frequency Converter (VFC) that was implemented in 130 nm CMOS technology. The proposed VFC was designed using the bulk-driven technique and can reliably work with the power supply voltage of 0.4 V.
Daniel Arbet +3 more
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A frequency to voltage converter with ultra-low residual frequency noise
CLEO Pacific Rim Conference, 2018We report on the process of residual noise suppression in a frequency to voltage converter based on a frequency difference multiplication method, for measuring frequency noise of ultra-stable laser. The double sideband frequency noise is lower than −40 dB Hz2/Hz in a bandwidth from 3 Hz to 100 kHz.
Lulu Yan +6 more
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