scholarly journals Microwave response characteristics and influencing factors of ores based on dielectric properties of synthetic samples

Author(s):  
Feng Lin ◽  
Xia-Ting Feng ◽  
Chengxiang Yang ◽  
Shiping Li ◽  
Jiuyu Zhang ◽  
...  
2013 ◽  
Vol 300-301 ◽  
pp. 810-813 ◽  
Author(s):  
Guo Jun Zhang ◽  
Yun Ju Yan

The SEA model of hypersonic aircraft is established based on statistical energy analysis (SEA) theory. Three parameters of the SEA model are established by the theory and experiential formula. According to damping loss factors of model subsystem and acoustic absorptivity of cavity, sensitivity analysis of vibro-acoustic response is discussed. The effect that division way of plate subsystem and material structure cause to vibro-acoustic response is analyzed. The analysis results show that the material structure, damping loss factors and material type have the great effect on the characteristics of vibro-acoustic response. The division way of plate subsystem can affect computational accuracy greatly. The influencing factors should be synthetically considered in the design of acoustics structure.


Foods ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1472
Author(s):  
Yu-Kai Weng ◽  
Jiunyuan Chen ◽  
Ching-Wei Cheng ◽  
Chiachung Chen

The dielectric properties of food materials is used to describe the interaction of foods with electromagnetic energy for food technology and engineering. To quantify the relationship between dielectric properties and influencing factors, regression analysis is used in our study. Many linear or polynomial regression equations are proposed. However, the basic assumption of the regression analysis is that data with a normal distribution and constant variance are not checked. This study uses sixteen datasets from the literature to derive the equations for dielectric properties. The dependent variables are the dielectric constant and the loss factor. The independent variables are the frequency, temperature, and moisture content. The dependent variables and frequency terms are transformed for regression analysis. The effect of other qualitative factors, such as treatment method and the position of subjects on dielectric properties, are determined using categorical testing. Then, the regression equations can be used to determine which influencing factors are important and which are not. The method can be used for other datasets of dielectric properties to classify influencing factors, including quantitative and qualitative variables.


2015 ◽  
Vol 73 (3) ◽  
Author(s):  
Mohd Hafiz Fazalul Rahiman ◽  
Thomas Tan Wan Kiat ◽  
Soh Ping Jack ◽  
Ruzairi Abdul Rahim

The objective of this paper is to review microwave tomography based on its field, application and antennas approaches. Researches on microwave tomography system have been done unceasingly for several decades especially in determine the dielectric properties for the material. Firstly, the dielectric properties and its influencing factors will be briefly described. Besides, although it has the potential to overcome other process tomography system, it still have some drawbacks. So, the general advantages and disadvantages are listed. Next, survey on the application of microwave tomography and type of antennas used will be discussed. Followed by the trend for the future.


2021 ◽  
Vol 10 (1) ◽  
pp. 671-679
Author(s):  
Ying Li ◽  
Zhengkang Xu ◽  
Aili Jia ◽  
Xulin Yang ◽  
Wei Feng ◽  
...  

Abstract Helical carbon nanotubes (HCNTs) are a kind of potential microwave absorption (MA) material due to their chiral and dielectric properties. However, the inert surface property makes HCNTs with poor polarization loss ability and impedance matching characteristic, which impedes its ability in attenuating microwaves. Herein, the HCNTs were modified with defects and functional groups on the surface to optimize their electromagnetic response characteristics and achieve an enhanced MA performance. The experimental results show that the modified HCNTs (F-HCNTs) exhibit a significant enhancement in MA performance when compared with HCNTs. The minimum reflection (RLmin) loss of F-HCNTs reaches −45.4 dB at 17.5 GHz at a thickness of 2.4 mm and the bandwidth of RL < −10 dB is 3.6 GHz (from 14.4 to 18.0 GHz). Further analysis demonstrates that proper modification of HCNTs leads to enhanced dielectric loss ability and optimized impedance matching characteristics, both of which are beneficial to the MA performance of HCNTs.


2000 ◽  
Vol 14 (1) ◽  
pp. 1-10 ◽  
Author(s):  
Joni Kettunen ◽  
Niklas Ravaja ◽  
Liisa Keltikangas-Järvinen

Abstract We examined the use of smoothing to enhance the detection of response coupling from the activity of different response systems. Three different types of moving average smoothers were applied to both simulated interbeat interval (IBI) and electrodermal activity (EDA) time series and to empirical IBI, EDA, and facial electromyography time series. The results indicated that progressive smoothing increased the efficiency of the detection of response coupling but did not increase the probability of Type I error. The power of the smoothing methods depended on the response characteristics. The benefits and use of the smoothing methods to extract information from psychophysiological time series are discussed.


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