Measuring the dielectric properties of date palm fruit, date palm leaflet, and Dubas bug at radio and microwave frequency using two-port coaxial transmission/reflection line technique
| Autor: | Kambiz Afrooz, M. Shamsi, Mohammad Ali Rostami, Motahareh Vaezi Zadeh |
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| Rok vydání: | 2019 |
| Předmět: |
Materials science
Acoustics Loss factor 010401 analytical chemistry Soil Science 04 agricultural and veterinary sciences Dielectric 01 natural sciences 0104 chemical sciences Quality (physics) Control and Systems Engineering Dielectric heating 040103 agronomy & agriculture Reflection (physics) 0401 agriculture forestry and fisheries Radio frequency Coaxial Penetration depth Agronomy and Crop Science Food Science |
| Zdroj: | Biosystems Engineering. 181:73-85 |
| ISSN: | 1537-5110 |
| DOI: | 10.1016/j.biosystemseng.2019.03.003 |
| Popis: | This paper presents a simple, innovative and effective procedure for measuring the dielectric properties of materials over a frequency range, based on the coaxial transmission/reflection method. The technique can measure the dielectric properties of materials from low to high loss with different sample sizes at different temperatures over a wide frequency range. The designed setup is tested and verified using air and polyamide samples, and simulated with 3D-electromagnetic software. Newer physical methods including dielectric heating have been considered, but information on the dielectric properties of date fruit, leaflet and Dubas bug, which causes great damage by reducing the quality and quantity of the date palm fruits in several countries, are lacking. The dielectric properties of date fruit, leaflet, and Dubas bug are measured at five temperatures between 20 and 60 °C and over the frequency range from 14 to 915 MHz. The experimental and simulation results show good statistical agreement. The designed setup is very useful for materials with low to high loss factor and for small objects like insects at different temperatures. The results show that the dielectric properties of the tested materials decrease with frequency and increase with temperature. Comparison of the dielectric loss factor of insects, date fruit, and leaflet shows that the insect differentially heats up faster than the date fruit and leaflet. The penetration depth decreases with increasing frequency and temperature. The results show that the dielectric heating at radio frequency might provide practical applications in controlling insects because of the differential heating and sufficient penetration depth. |
| Databáze: | OpenAIRE |
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