Article
Chemistry, Physical
K. S. Ashraff Ali, M. M. Ravikumar, J. Mohammed, Naeim Farouk, V. Mohanavel, M. Ravichandran
Summary: This study reported the microwave absorption properties of BaFe12O19, carbon fiber@Fe3O4 composite, and graphene@BaFe12O19@Fe3O4 composite, and their effects on the microwave absorption performance. Increasing filler loading in different combinations can enhance microwave absorption capabilities within a certain range.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Computer Science, Information Systems
Jurgen K. A. Nogueira, Joao G. D. Oliveira, Samuel B. Paiva, Valdemir P. Silva Neto, Adaildo G. D'Assuncao
Summary: A sensor is proposed to characterize the complex permittivity of dielectric materials in a non-destructive and non-invasive way. The sensor is based on a rectangular patch microstrip two-port circuit with a complementary split-ring resonator (CSRR) element. The sensitivity analysis is determined by varying the permittivity of the material under test (MUT). The proposed sensor is simulated and analyzed using Ansoft HFSS software, and the results show good agreement with measurements made on two different dielectric material samples with known complex permittivity values.
Article
Environmental Sciences
Umesh Chejara, Anamika Prajapati, Arvind Kumar
Summary: This study synthesized and characterized nano-particles of polycrystalline magnesium and iron ferrite doped with rare earth materials. The electrical properties of these materials were measured, and it was found that they exhibit variation behavior with respect to frequency. The study suggests that these materials may have potential applications in the fabrication of microwave antennas to reduce energy losses.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2023)
Article
Chemistry, Analytical
Nan Zhang, Bin Jiang, Shanshan Xue, Xiaolong Wang, Tianshuang Wang, Peng Sun, Geyu Lu
Summary: In this study, a novel analysis method based on variation of energy loss was proposed for the first time, and a microwave gas sensor for NH3 detection was successfully developed. The sensor showed a low detection limit, excellent selectivity, humidity-resistance, and good linearity for NH3 concentration.
SENSORS AND ACTUATORS B-CHEMICAL
(2022)
Article
Nanoscience & Nanotechnology
Azim Uddin, Diana Estevez, Rabia Khatoon, Faxiang Qin
Summary: With the miniaturization and integration of electronic components, the demand for low-cost flexible composites with temperature-stable high dielectric constant and low loss has increased. This study developed silicone elastomer composites based on hydrothermally grown MoS2 on tissue paper-derived cellulose carbon (CC). The composites showed high dielectric constant and low loss, as well as flexibility and temperature stability, making them attractive for microstrip antenna applications and extreme environment electronics.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Food Science & Technology
Rafael Perez-Campos, Jose Fayos-Fernandez, Juan Monzo-Cabrera
Summary: This study measured the permittivity of raw and boiled quinoa seeds and conducted experiments under various conditions such as temperature, moisture content, and bulk density. The results showed that both raw and boiled quinoa can be processed with microwave technology, but caution must be exercised with raw quinoa due to the significant increase in permittivity with temperature, which may lead to a thermal runaway.
CURRENT RESEARCH IN FOOD SCIENCE
(2023)
Article
Chemistry, Inorganic & Nuclear
Hafedh Belmabrouk, Mohammed A. Albedah, Rahma Ayed Brahem, Safwen Elkossi, Anouar Jbeli, Marwa Selmi
Summary: This paper investigates a new ceramic material with a BaTiO3-like structure, focusing on its synthesis, structure, and dielectric characteristics. The material was synthesized using the solid-state method and was found to have a cubic structure with the space group Pm-3m, as confirmed by X-ray diffraction analysis. The sample's crystalline and grain size were estimated to be approximately 147 nm and 1.43 μm, respectively, using Debye Scherrer's formula and SEM. The electrical conductivity data (AC) adhered well to Jonscher's power law, specifically the barrier hopping model (CBH). The DC conductivity revealed thermally activated conduction and semiconductor behavior. As the frequency increased, the dielectric permittivity (ε) decreased, which can be explained by Maxwell-Wagner's theory of interfacial polarization. Complex impedance spectra indicated the presence of a non-Debye relaxation phenomenon. Electrical modulus measurements revealed a thermally activated relaxation attributed to the Maxwell-Wagner (M-W) space charge relaxation phenomenon, with an activation energy (Ea) of approximately 0.623 eV.
INORGANIC CHEMISTRY COMMUNICATIONS
(2023)
Article
Engineering, Electrical & Electronic
Jun Zhang, Haidong Chen, Huibing Chen, Haitian Zhou, Wenquan Che, Quan Xue
Summary: A novel method for measuring anisotropic dielectric permittivity is proposed in this article, using a dual-mode system and the NRW method for excitation, which allows for one-time measurement without moving the material. By designing key components and setting up the measurement system, the experimental results demonstrate that this method is an effective and accurate solution for measuring the permittivity of anisotropic materials.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2022)
Article
Materials Science, Textiles
Yaya Zhang, Jiyong Hu, Xiong Yan, Huating Tu
Summary: The thickness and dielectric properties of fabric substrate are crucial in the design of wearable antennas, with a thicker substrate with low dielectric constant and high loss tangent enhancing antenna bandwidth. Sewing multiple fabrics together can increase thickness while maintaining flexibility, but controlling dielectric properties is challenging due to the lack of relationship between materials. A proposed circuit model was used to establish equivalent capacitance and resistance models for sewed multilayer fabric to predict its loss tangent, showing good agreement with experimental results and providing a basis for multilayer flexible electronic substrate design.
TEXTILE RESEARCH JOURNAL
(2022)
Article
Materials Science, Ceramics
M. D. Hossain, A. Masud, M. N. I. Khan, S. S. Sikder
Summary: Nanostructured Bi0.9Eu0.1FeO3 (BEFO), Ni0.6Zn0.4Fe2O4 (NZF), and (1-x).BEFO + x.NZF composites have been synthesized and characterized. The addition of NZF content in the composites modified their magnetic and dielectric properties. The optimized 0.9 BEFO + 0.1 NZF composite showed the highest permeability and dielectric values with the least amount of losses.
CERAMICS INTERNATIONAL
(2023)
Article
Materials Science, Multidisciplinary
Jakkree Boonlakhorn, Jirata Prachamon, Jutapol Jumpatam, Sriprajak Krongsuk, Prasit Thongbai, Pornjuk Srepusharawoot
Summary: By doping CdF2, the dielectric properties of the CaCu3Ti4O12/CaTiO3 binary-phase system can be improved. With increasing dopant concentration, the grain size decreases, the dielectric permittivity increases, and the loss tangent decreases. Impedance spectroscopy findings suggest that the tremendous dielectric response in this binary-phase system is due to an internal barrier layer capacitor.
RESULTS IN PHYSICS
(2022)
Article
Engineering, Electrical & Electronic
Dora Alejandra Chaparro-Ortiz, Reydezel Torres-Torres
Summary: The research determines the frequency-dependent complex permittivity for a printed circuit board laminate through systematic measurements of an array of striplines. A Debye model is implemented to provide a wideband representation of the relative permittivity and loss tangent, with the characteristic impedance of the lines reconstructed. Causal time-domain simulation results are also achieved.
IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS
(2021)
Article
Engineering, Chemical
Fucheng Zhang, Di Zhai, Xiaobiao Shang, Junruo Chen, Meihong Liu, Jinhui Peng
Summary: This study calculated the reflection loss of aspirin powder under different conditions and analyzed the impact of a dielectric-assisted absorbing layer on the microwave absorbing performance. The findings can help optimize microwave drying process parameters and equipment design.
Article
Materials Science, Ceramics
Hafiz Shehbaz Ahmad, Tanveer Hussain, Yasir Nawab, Shuaib Salamat
Summary: In this study, carbon fiber reinforced unidirectional composite (CFRC) structures were developed by adding various dielectric and magnetic nanofillers at a 2% loading concentration of the weight of the matrix. The microwave absorption properties were investigated in a wide frequency range, and it was found that the absorption increased with frequency, with the maximum value observed in the X frequency range (8.2-12.4 GHz)。
CERAMICS INTERNATIONAL
(2022)
Article
Polymer Science
Rafael Perez-Campos, Jose Fayos-Fernandez, Juan Monzo-Cabrera, Fernando Martin Salamanca, Juan Lopez Valentin, Jose Manuel Catala-Civera, Pedro Plaza-Gonzalez, Juan Rafael Sanchez-Marin
Summary: Efforts are being made to find innovative ways of recycling rubber from end-of-life tires through devulcanization. This study shows that microwave heating is a controllable and efficient method for devulcanizing the rubber, and the changes in the rubber's permittivity can be used to monitor the process.
