Journal of Microwave Power and Electromagnetic Energy最新文献

{"title":"Permittivity measurements for roasted ground coffee versus temperature, bulk density, and moisture content","authors":"R. Pérez-Campos, J. Fayos-Fernández, J. Monzó-Cabrera","doi":"10.1080/08327823.2023.2206666","DOIUrl":"https://doi.org/10.1080/08327823.2023.2206666","url":null,"abstract":"Abstract For a large variety of food products, the moisture content can be indirectly determined by measuring their dielectric properties. In the case of coffee, the permittivity knowledge can be applied to determine the moisture content indirectly or for online moisture meters in automatic control of coffee dryers. However, there is little data on the dielectric properties of roasted ground coffee near the 2.45 GHz ISM band. In this contribution, the permittivity was measured versus temperature, bulk density, and moisture content. A resonant technique based on a coaxial microwave cavity was employed to obtain the complex permittivity as a function of those magnitudes near the 2.45 GHz ISM band. In addition, the permittivity of the coffee particle kernel has been estimated from a complex refractive index mixture equation, thus calculating the permittivity of the coffee particle kernel from the permittivity values of the mixture air-coffee (ground coffee) at different bulk densities. The results showed that both dielectric constant and loss factor increase for increasing temperature, bulk density, and moisture content values. Furthermore, expressions fitting the experimental data were provided, thereby facilitating the estimation of the values throughout the studied temperature, bulk density, and moisture content ranges.","PeriodicalId":16556,"journal":{"name":"Journal of Microwave Power and Electromagnetic Energy","volume":"67 1","pages":"102 - 116"},"PeriodicalIF":1.5,"publicationDate":"2023-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89036188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating the influence of marination and storage on microwave dielectric properties of chicken breast meat","authors":"S. Trabelsi","doi":"10.1080/08327823.2023.2207604","DOIUrl":"https://doi.org/10.1080/08327823.2023.2207604","url":null,"abstract":"Abstract Simultaneous influence of marination and storage on dielectric properties of chicken meat was investigated through dielectric measurements at microwave frequencies. For this purpose, an open-ended coaxial probe and a vector network analyzer were used for measurement of the dielectric properties between 200 MHz and 20 GHz and at a room temperature of 22 °C. For all chicken samples, the same general trend was observed for the variations of dielectric properties with frequency. The dielectric constant decreased with frequency with significant slope change at about 5 GHz. The dielectric loss factor decreased sharply up to 2 GHz and then increased with frequency showing a broad relaxation above 8 GHz. Values of the dielectric constant and dielectric loss factor measured for marinated chicken meat samples were greater than those of non-marinated samples and this was more significant for the dielectric loss factor at lower frequencies. In addition, each level of marination was distinctly observed over the same frequency range. Investigation of the influence of storage revealed that the dielectric loss factor of marinated samples decreased over the storage period while those of non-marinated sample slightly increased with storage time. For both marinated and non-marinated samples, water loss increased with storage time.","PeriodicalId":16556,"journal":{"name":"Journal of Microwave Power and Electromagnetic Energy","volume":"1 1","pages":"117 - 128"},"PeriodicalIF":1.5,"publicationDate":"2023-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76987093","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study of multi-frequency heating based on the nonlinear response characteristics of magnetron to improve uniformity","authors":"Mengna Du, Zihao Zhang, Jie Huang, Huacheng Zhu, Yang Yang","doi":"10.1080/08327823.2023.2166003","DOIUrl":"https://doi.org/10.1080/08327823.2023.2166003","url":null,"abstract":"Abstract The majority of microwave ovens on the market are powered by magnetrons, which can only produce a narrow-band frequency that has a large peak, resulting in poor uniformity. A method is proposed to improve nonuniform heating based on nonlinear response characteristics of the magnetron to produce multi-frequency. First, a multi-physics model of microwave heating is established to realize the calculation of multi-frequency heating. Second, a multi-frequency heating experimental system based on the characteristics of the magnetron is built and verified with the calculated results. The results show that the calculated results are in good agreement with the experimental results. Finally, based on the multi-physics model, the influences of different parameters, such as frequency intervals, cavity size, location of the object to be heated and material properties, on microwave heating uniformity have also been discussed. The results show that the method adopted in this paper is feasible, and the heating uniformity of microwaves is improved.","PeriodicalId":16556,"journal":{"name":"Journal of Microwave Power and Electromagnetic Energy","volume":"7 1","pages":"71 - 88"},"PeriodicalIF":1.5,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74439005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Editor’s message: textbooks for helping new generations to see further","authors":"Juan Antonio Aguilar Garib","doi":"10.1080/08327823.2023.2169226","DOIUrl":"https://doi.org/10.1080/08327823.2023.2169226","url":null,"abstract":"The best-known source of the quote ‘If I have seen a little further, it is by standing on the shoulders of giants’ has been taken from a letter of Sir Isaac Newton to Robert Hooke, expressing a sort of recognition to Descartes on his studies of light. Sir Isaac Newton was a Lucasian Professor (he held the Lucasian Chair of Mathematics at the University of Cambridge), so probably it is more than a coincidence that the same idea is the basis of the title of a compilation of scientific texts edited and commented by another Lucasian Professor, Stephen Hawking, ‘On the shoulders of giants: The great works of physics and astronomy’, which is about the contributions of Nicolaus Copernicus, Galileo Galilei, Johannes Kepler, Sir Isaac Newton, and Albert Einstein. The reference to giants is metaphoric, recognizing the importance of the work performed by the predecessors as the base of the new findings. It cannot be another way, as the rise of civilization has depended on the capacity of each generation to remember what was learned by the previous ones. Oral and master-apprentice methods were the most common ways for passing knowledge from generation to generation, but they were limited due to the chances of forgetting or misunderstanding shared thoughts. There are many references to accidental learning, but it is likely improbable compared to needdriven research that could emerge, once again after certain learning is forgotten, with the repetition of similar experiences and reinventions along different generations. Perhaps writing is also a need-driven development so it was invented by different cultures. It was a great leap since it made it possible to transmit information through generations, despite the loss or death of those who generated it, and then have knowledge accumulation. This is the medulla of recognition to ancient people who left their legacy in innumerable documents and books. There are many factors that affect the path to reaching a high level of culture and technology to become a civilization. Knowledge generation requires people prepared to do so, it is not the available information, but the method to get data, produce information through analysis, and then have knowledge. Climbing on the shoulders of giants who left their legacy requires certain abilities and skills, therefore growing up is not fortuitous, as people are taught to seek out, and learn. The people with the necessary abilities to create inventions, apply knowledge, and generate it, are in principle formed in educative institutions, earning their academic degrees in sciences and engineering. During the process, they must learn and understand wellestablished knowledge, which has been produced over centuries. The teaching-learning process mainly depends on the student, who must assimilate the information that receives from the professor and the study material. A very important auxiliary in this process is the textbook of every subject because they compile the generated knowled","PeriodicalId":16556,"journal":{"name":"Journal of Microwave Power and Electromagnetic Energy","volume":"1 1","pages":"1 - 2"},"PeriodicalIF":1.5,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83086923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advantages and problems of electric microwave processing plants with hybrid working chambers","authors":"Midhat Tuhvatullin, Yuriy Arkhangelsky, R. Aipov, A. Akhmetshin, D. Atnagulov","doi":"10.1080/08327823.2023.2166004","DOIUrl":"https://doi.org/10.1080/08327823.2023.2166004","url":null,"abstract":"Abstract This article presents information about the design and purpose of microwave processing plants of thermal, non-thermal microwave modification and microwave processing plants with hybrid working chambers that have not yet been widely used. This article also presents and justifies advantages of electric microwave processing plants with hybrid chambers over electric microwave processing plants used for thermal treatment of dielectric materials and non-thermal treatment of polymer materials. These advantages give reason to talk about the expediency of widespread use of electric microwave processing plants with hybrid working chambers in industry and agriculture. This article formulates and justifies the problems of electric microwave processing plants with hybrid working chambers. Thus, high prices for microwave generators reduce the profitability of the plant. The research is being carried out within the framework of a grant as subsidies in science from the budget of the Republic of Bashkortostan for the state support of young scientists – candidates of sciences (the competition code is REC–Federal and State Management – 2022).","PeriodicalId":16556,"journal":{"name":"Journal of Microwave Power and Electromagnetic Energy","volume":"40 1","pages":"55 - 70"},"PeriodicalIF":1.5,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81015057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of microwave dryers on the properties of Jerusalem artichoke: physico-chemical, thermo-physical, energy consumption","authors":"Burcu Aksüt, S. Dursun, H. Polatcı, M. Taşova","doi":"10.1080/08327823.2023.2166005","DOIUrl":"https://doi.org/10.1080/08327823.2023.2166005","url":null,"abstract":"Abstract Effects of pretreatments and drying methods on physico-chemical, thermo-physical, energy values were investigated. The longest drying duration was seen in control samples dried in hybrid microwave dryer at 350 W + 50 °C and the shortest in citric acid-treated samples dried in temperature-controlled microwave dryer. Citric acid-treated samples dried in temperature-controlled microwave dryer at 70 °C had the closest color values to fresh ones. Effective diffusion values of dried Jerusalem artichoke samples varied between 4.66 x 10−8 − 1.33 x 10−7 m2 s−1 and activation energy values varied between 14.53 − 41.74 kJ mol−1. Drying date was estimated with the Midilli-Küçük model. The highest specific heat, thermal conductivity and thermal diffusivity values were observed in control samples dried in temperature-controlled microwave oven at 60 °C and the highest density values were seen in citric acid-treated samples dried in hybrid microwave oven at 70 °C. The highest SMER value was observed in control samples dried in temperature-controlled microwave dryer at 60 °C. The lowest SEC value was seen in control samples dried in temperature-controlled microwave dryer at 60 °C. The lowest total energy consumption was encountered in citric acid-treated samples dried in temperature-controlled microwave dryer at 70 °C.","PeriodicalId":16556,"journal":{"name":"Journal of Microwave Power and Electromagnetic Energy","volume":"105 1","pages":"28 - 43"},"PeriodicalIF":1.5,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77571000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Theoretical and experimental studies on localized electric field during microwave drilling of metals","authors":"Jiaying Yan, Shichun Li, Zhi Yang, Wenjing Cai, Min Ou, Junzhe Li","doi":"10.1080/08327823.2023.2166084","DOIUrl":"https://doi.org/10.1080/08327823.2023.2166084","url":null,"abstract":"Abstract Microwave drilling (MWD) is a nontraditional machining process. To further reveal the mechanism of the MWD of metals, a physical model of the electric field during the MWD was established and mathematically solved. Microwave drilling experiments were performed, and an ultra-depth microscope was used to investigate MWD morphologies under different conditions (gap scale d and tip radius R). By comparing the characteristics of the MWD morphology and the distributions of electric field strength, the relationship between the MWD morphology characteristics and electric field strength distribution on the workpiece was revealed. The effects of the gap scale d and tip radius R on the MWD morphology and electric field strength distributions were also analyzed. The results of this study can be helpful in enhancing the understanding of the MWD mechanism and the prediction of machining accuracy and surface quality.","PeriodicalId":16556,"journal":{"name":"Journal of Microwave Power and Electromagnetic Energy","volume":"9 1","pages":"44 - 54"},"PeriodicalIF":1.5,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86223940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measurement and modelling of organic matter’s altering effect on dielectric behavior of soil in the region of 200 MHz to 14 GHz","authors":"Prachi Palta, Prabhdeep Kaur, K. S. Mann","doi":"10.1080/08327823.2023.2167154","DOIUrl":"https://doi.org/10.1080/08327823.2023.2167154","url":null,"abstract":"Abstract Organic matter (OM) is one of the parameters which is commonly ignored while studying the properties of soil but it strongly affects and alters soil’s behavior and characteristics. The presented study analyzes the properties of soil like bulk density, and dielectric properties and penetration depth, emissivity, and conductivity as a function of OM (0.78–17.28% of total soil mass), moisture content (15–25% volumetric basis), and frequency (200 MHz–14 GHz). The properties have been investigated using a vector network analyzer (VNA), and an open-ended coaxial probe (85070E, Agilent Technologies). The observed results showed that in addition to moisture content and frequency, the amount of OM present in soil strongly affects the properties of soil. The OM present in soil improves soil structure as well as binding forces in soil water molecules. Third-order Response surface method (RSM) regression models are generated to estimate soil’s properties as a function of OM, frequency, and moisture content. These models show a R2 score of 0.9754, 0.9964, 0.9204, 0.9962, 0.9827, 0.9859 for bulk density, penetration depth, conductivity, and emissivity, respectively. These models can be helpful for fast and accurate prediction of properties of soil under the effect of OM, moisture content, and frequency.","PeriodicalId":16556,"journal":{"name":"Journal of Microwave Power and Electromagnetic Energy","volume":"38 1","pages":"3 - 27"},"PeriodicalIF":1.5,"publicationDate":"2023-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79390749","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dielectric properties of cereal stubble infected with Bipolaris sorokiniana, Fusarium pseudograminearum and Pyrenophora teres in the microwave frequency range","authors":"Toni Petronaitis, G. Brodie, S. Simpfendorfer, R. Flavel, N. Warwick","doi":"10.1080/08327823.2022.2142754","DOIUrl":"https://doi.org/10.1080/08327823.2022.2142754","url":null,"abstract":"Abstract Cereal production in Australia is severely impacted by stubble-borne pathogens which can survive multiple seasons within cereal residues (stubble). Microwave radiation may be able to reduce or eliminate the pathogens, but the energy requirements first need defining. Hence, the dielectric properties of wheat and barley stubble with different pathogen loads were investigated at 10%, 15%, 30% and 100% moisture content using an open-ended coaxial probe in a spectral band covering 915, 2450, and 5800 MHz. A significant increase in dielectric constant and loss factor was observed with increasing stubble moisture. The dielectric constant and loss factor were lower in the crown (basal) section of stubble compared with the stem (20 cm from base), due to differences in density. When stubble moisture was 100%, the loss factor of barley was higher than wheat. Infection of stubble by different pathogens did not affect the dielectric properties. Microwave heating could therefore be an effective method to heat cereal stubble to eradicate a range of cereal pathogens, especially at lower frequencies and high moisture content, at which the loss factor is high. This research serves as a starting point to define requirements for further development of effective microwave radiation treatments under field conditions.","PeriodicalId":16556,"journal":{"name":"Journal of Microwave Power and Electromagnetic Energy","volume":"83 2 1","pages":"219 - 237"},"PeriodicalIF":1.5,"publicationDate":"2022-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77418793","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Use of dielectric properties measurements at microwave frequencies for real-time monitoring of water activity in almonds","authors":"S. Trabelsi","doi":"10.1080/08327823.2022.2142755","DOIUrl":"https://doi.org/10.1080/08327823.2022.2142755","url":null,"abstract":"Abstract A dielectric-based method for real-time tracking of changes in water activity in almond kernels is proposed. The method is based on measurement of the dielectric properties at a single microwave frequency. Samples of almond kernels (Butte/Padre and Nonpareil) were placed in a chamber with high humidity and their dielectric properties were measured at 10 GHz and room temperature (22 °C) every few hours. The dielectric properties increased linearly with time and exponentially with water activity. A three-parameter exponential growth equation provided relationships correlating the dielectric constant (ε’), the dielectric loss factor, (ε”), and the loss tangent (ε”/ε’) with water activity with high coefficients of determination (r2 ). From these equations, water activity calibration equations were obtained. Performance of these equations in predicting water activity under dynamic situations were assessed by calculating the standard error of calibration (SEC). Values of SEC ranged from 0.01 to 0.05.","PeriodicalId":16556,"journal":{"name":"Journal of Microwave Power and Electromagnetic Energy","volume":"19 1","pages":"259 - 267"},"PeriodicalIF":1.5,"publicationDate":"2022-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88175895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}