查看更多>>摘要：? 2022 Elsevier LtdAccurate dielectric characterization of liquid materials is critical for a wide range of applications. In this paper, a permittivity measurement method featuring a planar immersible probe consisting of a small loop loaded with a spiral resonator is presented. The design of the probe is described herein, and its performance is demonstrated through measurements and benchmarking with a widely accepted commercial dielectric measurement solution. It is shown that the probe renders accurate permittivity values for various edible oils, crude oil and ethanol solutions with varying concentrations.
查看更多>>摘要：? 2022 Elsevier LtdThe Fourier decomposition method (FDM) is a useful method for signal decomposition. However, FDM has the problems of over decomposition and time-consuming. Therefore, a peak envelope spectrum Fourier decomposition method (PESFDM) is proposed in this paper. Firstly, the upper peak envelope is used to process the signal spectrum and obtain the peak envelope spectrum. Secondly, the segmentation boundaries are adaptively determined on the peak envelope spectrum using a modified “Locmaxmin” spectrum segmentation method. The bands between the segmentation boundaries are then reconstructed into several single-component signals. Finally, the proposed method is used to decompose the simulated and actual bearing fault signals. The results are compared against the other four signal processing methods: empirical mode decomposition, empirical wavelet transform, FDM, and adaptive power spectrum Fourier decomposition method. The results show that the proposed method has a more effective spectrum segmentation and a better effect of fault diagnosis.
NSTL
Elsevier