Electrical Properties of Materials

Nature ◽  
1958 ◽  
Vol 182 (4628) ◽  
pp. 73-73
Electronics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 393
Author(s):  
Huthaifa Obeidat ◽  
Atta Ullah ◽  
Ali AlAbdullah ◽  
Waqas Manan ◽  
Omar Obeidat ◽  
...  

This paper outlines a study of the effect of changing the electrical properties of materials when applied in the Wireless InSite (WI) ray-tracing software. The study was performed at 60 GHz in an indoor propagation environment and supported by Line of Sight (LoS) and Non-LoS measurements data. The study also investigates other factors that may affect the WI sensitivity, including antenna dimensions, antenna pattern, and accuracy of the environment design. In the experiment, single and double reflections from concrete walls and wooden doors are analysed. Experimental results were compared to those obtained from simulation using the WI. It was found that materials selected from the literature should be similar to those of the environment under study in order to have accurate results. WI was found to have an acceptable performance provided certain conditions are met.


2011 ◽  
Vol 312-315 ◽  
pp. 1216-1221
Author(s):  
Norlida Kamarulzaman ◽  
Roshidah Rusdi ◽  
Nor Diyana Abdul Aziz ◽  
Lili Widarti Zainudin ◽  
Zurina Osman

The diffusion of charged species in solids is a very important part of the study of the electrical properties of materials. Electrical measurements using alternating current (ac) impedance is a powerful technique to study diffusing species in metal oxides as well as polymers. Three case studies are being presented here whereby the electrical properties of LiTaO3, Poly[2-methoxy-5-(2’-ethylhexyloxy)-(p-phenylenevinylene)] (MEH-PPV) and its composite are being studied using the same ac impedance technique. LiTaO3 is a metal oxide while MEH-PPV is a polymer. They are very different and therefore present very good examples for the versatility and power of ac impedance method. Electrical parameters such as conductivity and conduction behaviours of the conducting species can be extracted from the studies. The kinetics of the diffusing species can be elucidated by using proper analytical techniques.


2014 ◽  
Vol 17 (4) ◽  
pp. 109-113 ◽  
Author(s):  
Ján Novák ◽  
Ivan Vitázek

Abstract This work contains the results of measuring the electrical properties of sunflower achenes. The interest in electrical properties of biological materials resulted in engineering research in this field. The results of measurements are used for determining the moisture content, the surface level of liquid and grainy materials, for controlling the presence of pests in grain storage, for the quantitative determination of mechanical damage, in the application of dielectric heating, and in many other areas. Electrical measurements of these materials are of fundamental importance in relation to the analysis of quantity of absorbed water and dielectric heating characteristics. It is a well-known fact that electrical properties of materials, namely dielectric constant and conductivity, are affected by the moisture content of material. This fact is important for the design of many commercial moisturetesting instruments for agricultural products. The knowledge of dielectric properties of materials is necessary for the application of dielectric heating. The aim of this work was to measure conductivity, dielectric constant and loss tangent on samples of sunflower achenes, the electrical properties of which had not been sufficiently measured. Measurements were performed under variable moisture content and the frequency of electric field ranging from 1 MHz to 16 MHz, using a Q meter with coaxial probe. It was concluded that conductivity, dielectric constant and loss tangent increased with increasing moisture content, and dielectric constant and loss tangent decreased as the frequency of electric field increased.


2021 ◽  
Vol 21 (1) ◽  
pp. 51-59
Author(s):  
Jin-Seob Kang ◽  
Jeong-Hwan Kim

The electrical properties of materials and their dependence on frequency and temperature are indispensable in designing electromagnetic devices and systems in various areas of engineering and science for both basic and applied researches. A free-space transmission/reflection method measuring the free-space scattering parameters of a material under test (MUT) located at the middle of transmit/receive antennas in a free space is suitable for non-destructively testing the MUT without prior machining or physical contact in high-frequency range. This paper describes a planar offset short applicable to the calibration of a quasi-optic based free-space material measurement system in the millimeter-wave frequency range. The measurement results of the dimensional and electrical properties for the three fabricated planar offset shorts with the phase difference of 120° between the reflection coefficients of the planar shorts in the W-band (75–110 GHz) are presented.


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