100 kHz Homodyne, 35 GHz Reflection‐Cavity Spectrometer with Phase‐Lock of the Reference Signal and Low Frequency Field Modulation

1967 ◽  
Vol 38 (3) ◽  
pp. 339-347 ◽  
Author(s):  
H. C. Praddaude
Keyword(s):  
Reference Signal ◽  
Low Frequency ◽  
Phase Lock ◽  
Frequency Field ◽  
Field Modulation

de Haas–van Alphen Effect in Antimony–Tellurium Alloys

1975 ◽  
Vol 53 (5) ◽  
pp. 459-464 ◽  
Author(s):  
Z. Altounian ◽  
W. R. Datars
Keyword(s):  
Fermi Surface ◽  
Low Frequency ◽  
Band Model ◽  
Tin Alloys ◽  
Frequency Field ◽  
Modulation Technique ◽  
Field Modulation

The de Haas–van Alphen frequencies, cyclotron masses, and Dingle temperatures of antimony–tellurium alloys with up to 0.11 at. % Te were measured using the low frequency field modulation technique. The hole and electron frequencies decreased and increased respectively, as predicted by the rigid band model. At the highest concentration, the increase is about 25% that of pure Sb and the decrease is about 20%. The cyclotron masses of electrons and holes changed with concentration. This dependence resulted from the nonparabolicity of the Sb bands. Estimates of the Fermi surface volume of the alloys indicated that each Te atom contributes one electron to the alloy. The present results are compared with previous de Haas–van Alphen results on antimony–tin alloys.

Numerical errors in the scalar potential formulations used in low-frequency field problems

2000 ◽  
Vol 36 (5) ◽  
pp. 3096-3098 ◽  
Author(s):  
K. Sivasubramaniam ◽  
S. Salon ◽  
M.V.K. Chari
Keyword(s):  
Scalar Potential ◽  
Low Frequency ◽  
Numerical Errors ◽  
Frequency Field

scholarly journals Use of Transforms in Biomedical Signal Processing and Analysis

2021 ◽  
Author(s):  
Ette Harikrishna ◽  
Komalla Ashoka Reddy
Keyword(s):  
Wavelet Transforms ◽  
Research Work ◽  
Reference Signal ◽  
Low Frequency ◽  
Motion Artifact ◽  
Motion Artifacts ◽  
Biomedical Signal Processing ◽  
Blood Oxygen Saturation ◽  
Biomedical Signals ◽  
Electrocardiogram Ecg

Biomedical signals like electrocardiogram (ECG), photoplethysmographic (PPG) and blood pressure were very low frequency signals and need to be processed for further diagnosis and clinical monitoring. Transforms like Fourier transform (FT) and Wavelet transform (WT) were extensively used in literature for processing and analysis. In my research work, Fourier and wavelet transforms were utilized to reduce motion artifacts from PPG signals so as to produce correct blood oxygen saturation (SpO2) values. In an important contribution we utilized FT for generation of reference signal for adaptive filter based motion artifact reduction eliminating additional sensor for acquisition of reference signal. Similarly we utilized the transforms for other biomedical signals.

Quantum dynamics of a millikelvin quasibound KRb complex in a low-frequency field

2019 ◽  
Vol 100 (6) ◽  
Author(s):  
J. S. Molano ◽  
K. D. Pérez ◽  
J. C. Arce ◽  
J. G. López ◽  
M. L. Zambrano
Keyword(s):  
Quantum Dynamics ◽  
Low Frequency ◽  
Frequency Field

Control of photodetachment through a two-color low-frequency field

1998 ◽  
Vol 57 (1) ◽  
pp. R16-R19 ◽  
Author(s):  
S. Bivona ◽  
R. Burlon ◽  
C. Leone
Keyword(s):  
Low Frequency ◽  
Frequency Field

FEASIBILITY STUDIES FOR THE IMPLEMENTATION OF NUCLEAR MAGNETIC RESONANCE IN A 25T HYBRID MAGNET

2002 ◽  
Vol 16 (20n22) ◽  
pp. 3405-3405
Author(s):  
P. J. M. VAN BENTUM ◽  
J. C. MAAN ◽  
J. W. M. VAN OS ◽  
A. P. M. KENTGENS
Keyword(s):  
Magnetic Resonance ◽  
Power Supply ◽  
Reference Signal ◽  
Low Frequency ◽  
Feasibility Studies ◽  
Feedback System ◽  
Hybrid Magnet ◽  
Simultaneous Acquisition ◽  
Field Fluctuations ◽  
Main Components

As an exploratory study for NMR experiments in the future 20 MW Nijmegen high field magnet laboratory, the possibilities of field stabilization and field gradient compensation in a 25 T hybrid magnet in the present installation were evaluated. High frequency field fluctuations from the power supply can be compensated to better than 10-3 ppm in the 10 Hz-10 kHz range using a computer controlled feedback system. Field mapping by 2H magnetic resonance using a homebuilt device not only showed that there are substantial axial but also strong radial field gradients. It can be shown that for any cylindrical multicoil Bitter magnet the main components of these gradients can be compensated with simple ferromagnetic inserts. In this way we achieved a linewidth under 5 ppm in 1 mm3 without further shimming or optimization. The low frequency drift of the field due to instabilities of the present power supply and the effects of temperature fluctuations of the coil are determined by simultaneous acquisition of an in-situ deuterium reference signal together with the signal of interest. This allows for a full compensation of the field fluctuations by deconvolution techniques. We will report preliminary NMR results on solid27 Al samples in fields up to 25 T.

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