Dielectric Measurement Of Multi-Layered Medium Using An Open-Ended Waveguide

1996 ◽  
Vol 430 ◽  
Author(s):  
O. Tantot ◽  
M. Chatard-Moulin ◽  
P. Guillon
Keyword(s):  
Reflection Coefficient ◽  
Complex Permittivity ◽  
Layered Medium ◽  
Circular Waveguide ◽  
Air Gap ◽  
Dielectric Measurement ◽  
Microwave Measurement ◽  
Measurement Devices

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.

NOISE MEASUREMENTS FOR MATERIAL DIELECTRIC CHARACTERIZATION: APPLICATION TO A LIQUID CRYSTAL

2001 ◽  
Vol 01 (03) ◽  
pp. L125-L130 ◽  
Author(s):  
LEROY GÉRARD ◽  
GEST JOËL ◽  
TABOURIER PIERRE
Keyword(s):  
Liquid Crystal ◽  
Complex Permittivity ◽  
Dielectric Material ◽  
Voltage Noise ◽  
The Real ◽  
Dielectric Characterization ◽  
Noise Measurements

In this paper, we show how noise measurements can be used for the characterization of a dielectric material. This nonperturbative technique allows the determination of the real and imaginary parts of the complex permittivity from current and voltage noise measurements. This technique is illustrated hereafter for the case of an antiferroelectric liquid crystal.

Characterization of Heavy Metal Contaminated Wastewater Using a Coaxial Sensor and Electromagnetic Wave Reflection Technique

2014 ◽  
Vol 548-549 ◽  
pp. 678-682 ◽  
Author(s):  
N. Puangngernmak ◽  
S. Chalermwisutkul
Keyword(s):  
Heavy Metal ◽  
Reflection Coefficient ◽  
Complex Permittivity ◽  
Industrial Wastewater ◽  
Frequency Range ◽  
Liquid Samples ◽  
Measurement Results ◽  
Interesting Approach ◽  
Copper Zinc

Industrial wastewater control is an important issue for protection of the environment. Liquid characterization using radio frequency signal is an interesting approach for selective detection of heavy metal contaminants in industrial wastewater. A simple sensor based on open-ended coaxial structure filled with the liquid under test is proposed. Liquid samples for the experiments are copper, zinc and nickel solutions with various concentrations of 1, 10, 100 and 1000 mg/liter each. From the measurement results using a vector network analyzer (VNA) in combination with the proposed sensor, the concentration of a specific contaminant can be determined by the magnitude of the measured reflection coefficient in a frequency range lower than 2 GHz. Applying a capacitive model of the sensor, complex permittivity of the liquid under test can be calculated from the measured reflection coefficient. Obvious relationship between the imaginary part of complex permittivity and the concentration of contaminant in a frequency range lower than 2 GHz was observed. The type of contaminants in the liquid samples can be identified by the position of the resonant peaks when the magnitude of reflection coefficient is plotted in the spectrum. The frequency range for contaminant’s identification lies between 2 and 3 GHz.

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
Keyword(s):  
Dielectric Constant ◽  
Reflection Coefficient ◽  
Complex Permittivity ◽  
Dielectric Permeability ◽  
Microwave Range ◽  
Electromagnetic Waveguide ◽  
The Relationship ◽  
Waveguide Method

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.

scholarly journals Continuous Characterization of Permittivity over a Wide Bandwidth Using a Cavity Resonator

2020 ◽  
Vol 20 (1) ◽  
pp. 39-44
Author(s):  
Rehab S. Hassan ◽  
Sung Ik Park ◽  
Ashwini Kumar Arya ◽  
Sanghoek Kim
Keyword(s):  
Complex Permittivity ◽  
Cavity Resonator ◽  
Dielectric Materials ◽  
Wide Frequency Range ◽  
Wide Bandwidth ◽  
Frequency Independent ◽  
5 Ghz ◽  
Continuous Determination

We examine a rectangular cavity resonator method to accurately characterize the complex permittivity of dielectric materials over a wide frequency range of 1–5 GHz by exploiting the fundamental mode and higher-order TE<sub>(1,0,<i>l</i>)</sub> modes. For this purpose, a rectangular waveguide is coupled with a cavity resonator through a large inductive aperture. The permittivity characterization at both even and odd TE<sub>(1,0,<i>l</i>)</sub> modes enables continuous determination of the permittivity over operating frequencies. The characterization of the permittivity for even TE<sub>(1,0,<i>l</i>)</sub> modes suffers from potential errors due to the displacement of materials. This paper also proposes a method to compensate for these errors and improve the accuracy in the even modes. The experimental results of the fabricated cavity are presented using different materials (frequency-independent and frequency-dependent). The measured complex permittivity results show a good agreement with the reported results over a wide bandwidth available in the literature.

scholarly journals Characterisation of dielectric 3D-printingmaterials at microwave frequencies

ACTA IMEKO ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 26
Author(s):  
Andrea Alimenti ◽  
Kostiantyn Torokhtii ◽  
Nicola Pompeo ◽  
Emanuele Piuzzi ◽  
Enrico Silva
Keyword(s):  
Quality Factor ◽  
Loss Tangent ◽  
Complex Permittivity ◽  
High Frequency ◽  
Measurement Method ◽  
Air Gap ◽  
3D Printer ◽  
Reliable Determination ◽  
Microwave Frequencies

<p class="Abstract">3D-printer materials are becoming increasingly appealing, especially for high frequency applications. As such, the electromagnetic characterisation of these materials is an important step in evaluating their applicability for new technological devices. We present a measurement method for complex permittivity evaluation based on a dielectric loaded resonator (DR). Comparing the quality factor <em>Q</em> of the DR with a disk-shaped sample placed on a DR base, with <em>Q</em> obtained when the sample is substituted with an air gap, allows a reliable determination of the loss tangent.</p>

Characterization of Impressed Current Technique to Model Corrosion of Reinforcement in Concrete

2020 ◽  
Vol 11 (1) ◽  
pp. 93-99
Author(s):  
Abu Zakir Morshed ◽  
Sheikh Shakib ◽  
Tanzim Jahin
Keyword(s):  
Immersion Time ◽  
Chloride Content ◽  
Engineering Science ◽  
Coastal Regions ◽  
Faraday’S Law ◽  
Current Technique ◽  
Corrosion Cell ◽  
Impressed Current

Corrosion of reinforcement is an important durability concern for the structures exposed to coastal regions. Since corrosion of reinforcement involves long periods of time, impressed current technique is usually used to accelerate the corrosion of reinforcement in laboratories. Characterization of impressed current technique was the main focus of this research,which involved determination of optimum chloride content and minimum immersion time of specimens for which the application of Faraday’s law could be efficient. To obtain optimum chloride content, the electrolytes in the corrosion cell were prepared similar to that of concrete pore solutions. Concrete prisms of 200 mm by 200 mm by 300 mm were used to determine the minimum immersion time for saturation. It was found that the optimum chloride content was 35 gm/L and the minimum immersion time for saturation was 140 hours. Accounting the results, a modified expression based on Faraday’s law was proposed to calculate weight loss due to corrosion. Journal of Engineering Science 11(1), 2020, 93-99

The Determination of Sense via Deleuze and Blanchot: Paradoxes of the Habitual, the Immemorial, and the Eternal Return

2008 ◽  
Vol 2 (2) ◽  
pp. 155-177 ◽  
Author(s):  
Eugene Brently Young
Keyword(s):  
Eternal Return

Eternal return is the paradox that accounts for the interplay between difference and repetition, a dynamic at the heart of Deleuze's philosophy, and Blanchot's approach to this paradox, even and especially through what it elides, further illuminates it. Deleuze draws on Blanchot's characterisations of difference, forgetting, and the unlivable to depict the ‘sense’ produced via eternal return, which, for Blanchot, is where repetition implicates or ‘carries’ pure difference. However, for Deleuze, difference and the unlivable are also developed by the living repetition or ‘contraction’ of habit, which results in his distinctive characterization of ‘force’, ‘levity’, and sense in eternal return.

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