scholarly journals Determination of dielectric permeability of substances by electromagnetic waveguide method

2020 ◽  
Vol 28 (1) ◽  
pp. 85-90
Author(s):  
Vikt. V. Ovsyanikov ◽  
E. R. Beznosova ◽  
L. Z. Tsypko ◽  
L. I. Filins’kyy ◽  
Vl. V. Ovsyanikov

A method for determining the complex permittivity of substances by the electromagnetic (EM) waveguide method in the microwave range using electrodynamics and the theory of multilayer dielectric structures is considered. The expression for the complex reflection coefficient of an EM wave in a waveguide with a substance sample is studied. Calculations of the dielectric constant of substances are carried out by analytical and numerical methods using computers. To obtain the desired complex permittivity of a substance, we use the relationship between the expression for the reflection coefficient modulus and the value of the standing wave coefficient over voltage measured in advance in the frequency range. The method is suitable for automation and application in enterprises producing and using fuels, construction and agricultural products. From the found value of the dielectric constant, the quality of substances can be determined. For example, the results of determining the dielectric constant several coals and solid-state foam are given.

2021 ◽  
Vol 1198 (1) ◽  
pp. 012012
Author(s):  
B G Tsydypov ◽  
A V Bazarov ◽  
B V Basanov ◽  
B Z Garmaev ◽  
E Yu Korovin ◽  
...  

Abstract Method and device for measuring the complex dielectric constant of liquids are described. The real part of the complex dielectric constant calculated from the conditions for the maximum and minimum of the measured interference dependence of the reflection coefficient on the layer depth. The imaginary part determined by selection to the maximum coincidence of the calculated and measured dependences of the reflection coefficient.


Author(s):  
Daniel Clarry

This chapter discusses the nature and operation of mandatory and default rules in fiduciary law, arguing that loyalty is a core element of every fiduciary legal institution. Loyalty is the hallmark of fiduciary law, as it requires persons in other-regarding positions of power to perform functions selflessly, rather than selfishly. However, there are many circumstances in which a person undertakes and exercises other-regarding powers, underscoring the fact that a broad range of persons may be the subject of fiduciary law. This chapter first provides an overview of key concepts and context, focusing on the distinction between mandatory rules and default rules as well as sources of such rules in fiduciary law. It then considers fiduciary loyalty, citing examples that illustrate how a baseline of fiduciary accountability is implied by the essential nature of fiduciary legal institutions, along with the mandatory or default quality of the duties of care and good faith. The main thesis of this chapter is that loyalty is a basic constituent element of all fiduciary legal institutions. Whether fiduciary principles are mandatory involves a consideration and determination of whether the relationship or institution is inherently fiduciary as matter of law and legal classification. It also highlights the modern trend toward codification and clear legislative demarcation of mandatory and default rules in fiduciary law.


1996 ◽  
Vol 430 ◽  
Author(s):  
O. Tantot ◽  
M. Chatard-Moulin ◽  
P. Guillon

AbstractThe use of a circular waveguide radiating into a multi-layered media allows the characterization of heterogeneous and fluid subtances. Many microwave measurement devices, based on reflection coefficient measurements, are subjected to air gap problems that introduce some inaccuracy in the determination of the unknown complex permittivity of the materials. Our purpose is to try and take the air gap into account in these measurements.


Geophysics ◽  
1976 ◽  
Vol 41 (2) ◽  
pp. 324-324
Author(s):  
W. T. Valenta

In their report, the authors recommend that the arrival of a compressional wave at a geophone or hydrophone shall ultimately produce a trough (downward or leftward kick) on a seismogram; but they don’t say why. On sonic logs and displays of velocity versus time, velocity increases are up; likewise for density increases on density logs; likewise for positive reflection coefficients on reflection coefficient logs computed from the previously mentioned logs. Should not seismograms, which ideally are bandlimited reflection coefficient logs, conform to the same convention? The committee succeeded in the objectives of establishing the relationship between impulse‐source systems and vibratory‐source systems and of establishing tests for the determination of the polarity of a given system. I feel strongly that the committee should recommend that a compressional arrival shall produce a peak on a seismogram.


1996 ◽  
Vol 430 ◽  
Author(s):  
C. J. Reddy ◽  
M. D. Deshpande ◽  
G. A. Hanidu

AbstractA simple waveguide measurement technique is presented to determine the complex permittivity of printed circuit board material. The printed circuit board with metal coating removed from both sides and cut into size which is the same as the cross section of the waveguide is loaded in a short X-band rectangular waveguide. Using a network analyzer, the reflection coefficient of the shorted waveguide(loaded with the sample) is measured. Using the Finite Element Method(FEM) the exact reflection coefficient of the shorted wavguide(loaded with the sample) is determined as a function of dielectric constant. Matching the measured value of the reflection coefficient with the reflection value calculated using FEM and utilizing Newton-Raphson Method, an estimate of the dielectric constant of a printed circuit board material is obtained. A comparison of estimated values of permittivity constant obtained using the present approach with the available data.


2021 ◽  
Vol 9 (B) ◽  
pp. 1751-1757
Author(s):  
S. B. Dyussenova ◽  
M. Y. Gordiyenko ◽  
G. B. Serikova ◽  
S. A. Turlybekova ◽  
A. A. Issayeva ◽  
...  

BACKGROUND: Vitamin D is essential for children and adults for healthy bone growth. Lack of this vitamin in children can cause rickets, and in adults, softening of the bones and an increased risk of fractures. Vitamin D deficiency can cause immune disorders, increased susceptibility to infections, the development of certain types of cancer, diabetes mellitus, and cardiovascular diseases. AIM: The article presents the literature data and the results of our own research on the analysis of the relationship between chronic kidney disease (CKD) and Vitamin D provision in children from 1 to 17 years old. The aim of the study was to establish the level of Vitamin D in children with different stages of CKD. METHODS: Between January 2020 and September 2020, we examined 40 children (16 boys and 24 girls). The patients’ age ranged from 1 to 17 years inclusive. RESULTS: Vitamin D deficiency was found in 62.5% of children with CKD. Vitamin D deficiency was noted in 25% of cases. The prevalence of Vitamin D deficiency correlates with a decrease in glomerular filtration rate. CONCLUSION: Determination of Vitamin D level in children with CKD is important for timely correction and prevention of further progression of CKD. Timely substitution therapy will improve the quality of life of a child with CKD and prevent the development of complications.


2005 ◽  
Vol 29 (3) ◽  
pp. 477-489
Author(s):  
Fu-Chen Chen ◽  
Hsing-Hui Huang

In this paper fuzzy logic was applied to the Taguchi method to design the dimensional tolerances of a six-bar hinge mechanism with multiple performance characteristics (MPC). A fuzzy logic system was used to determine the relationship between the S/N (signal to noise) ratios of the position and the angle error for assessing the level of importance of each control factor in the hinge mechanism. The contribution of each control factor to the variations was also quantified through the response table and response diagram and the key dimensions found to significantly affect the quality of the mechanism were r4, β, r1 and r5, which contributed 67.77% of the total product variation. It followed therefore that in order to improve the quality of the mechanism the tolerance of these factors must be tightened. Through a series of confirmation experiments, it was revealed that tightening the tolerance resulted in an increase in the multiple performance index (MPI) by 0.094, which was an increase of 19.87% of the initial value.


Author(s):  
Tushar ◽  
Tushar ◽  
Shibendu Shekhar Roy ◽  
Dilip Kumar Pratihar

Clustering is a potential tool of data mining. A clustering method analyzes the pattern of a data set and groups the data into several clusters based on the similarity among themselves. Clusters may be either crisp or fuzzy in nature. The present chapter deals with clustering of some data sets using Fuzzy C-Means (FCM) algorithm and Entropy-based Fuzzy Clustering (EFC) algorithm. In FCM algorithm, the nature and quality of clusters depend on the pre-defined number of clusters, level of cluster fuzziness and a threshold value utilized for obtaining the number of outliers (if any). On the other hand, the quality of clusters obtained by the EFC algorithm is dependent on a constant used to establish the relationship between the distance and similarity of two data points, a threshold value of similarity and another threshold value used for determining the number of outliers. The clusters should ideally be distinct and at the same time compact in nature. Moreover, the number of outliers should be as minimum as possible. Thus, the above problem may be posed as an optimization problem, which will be solved using a Genetic Algorithm (GA). The best set of multi-dimensional clusters will be mapped into 2-D for visualization using a Self-Organizing Map (SOM).


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