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Advanced kirigami/origami techniques have enabled the flexible transformation of planar patterns into exquisite three‐dimensional (3D) structures and provided a new paradigm to control electromagnetic waves with remarkable reconfigurability and functionality. The practical applications of kirigami/origami metasurfaces are prospective due to their diversified wave‐manipulation capabilities, which demonstrate advantages such as compactness, lightweightness, deployability, and scalability. In this article, a comprehensive overview of the most recent advancements in the field of kirigami/origami metasurfaces is provided. This includes the concept of kirigami/origami, the practical implementations of kirigami/origami meta‐structures, and the application aspects of kirigami/origami metasurfaces in the control of electromagnetic waves. In the conclusion, future challenges and promising pathways of this field are also envisioned from the own perspectives. [ABSTRACT FROM AUTHOR]

In this work, the theory of the modified unit sphere representation (mUSR) has been proposed as a computational tool suitable for the three‐dimensional representation of the pure electric‐dipole [βλμν(−2ω;ω,ω)] as well as of the mixed electric‐dipole/magnetic‐dipole [ αJλμν(−2ω;ω,ω) and βJλμν(−2ω;ω,ω)] or electric‐dipole/electric‐quadrupole [ αKλμνo(−2ω;ω,ω) and βKλμνo(−2ω;ω,ω)] first hyperpolarizabilities. These five quantities are Cartesian tensors and they are responsible for the chiral signal in the chiroptical version of the hyper‐Rayleigh scattering (HRS) spectroscopy, namely the HRS optical activity (HRS‐OA) spectroscopy. For the first time, for each hyperpolarizability, alongside with the three‐dimensional representation of the whole (i.e., reducible) Cartesian tensors, the mUSRs are developed for each of the irreducible Cartesian tensors (ICTs) that constitute them. This scheme has been applied to a series of three (chiral) hexahelicene molecules containing different degrees of electron‐withdrawing (quinone) groups and characterized by the same (positive) handedness. For these molecules, the mUSR shows that, upon substitution, the most remarkable qualitative and semi‐quantitative (enhancement of the molecular responses) effects are obtained for the pure electric‐dipole and for the mixed electric‐dipole/magnetic‐dipole hyperpolarizabilities. [ABSTRACT FROM AUTHOR]

In this study, we employed a high‐frequency‐driven thin‐film magnetic sensor to precisely measure the magnetic near field with enhanced spatial resolution, a challenge often faced by conventional loop antennas. Our study introduced an innovative approach utilizing this magnetic sensor to assess the magnetic near field in wireless power transfer systems, comparing its performance against that of a loop antenna. Our findings demonstrate that the magnetic sensor achieves its peak signal‐to‐noise ratio at a DC bias field of 4.7 Oe and carrier frequency of 0.5 GHz, boasting a detection limit for magnetic fields of ~0.4 A/m. Moreover, the magnetic field trend measured by the magnetic sensor closely aligns with simulation results, exhibiting sharper changes around the center compared to the loop antenna. These results highlight the superior sensitivity and spatial resolution of the magnetic sensor over conventional loop antennas. By enhancing the reliability of electronic systems across diverse applications, these sensors pave the way for advanced EMI/EMC evaluation techniques. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

The article presents the results of the development and experimental study that characterize the prototype of dual-polarization Yagi-Uda antenna for the meter wavelength range, which receives/transmits and selects electromagnetic energy in two orthogonal planes of linear polarization without additional mechanical (electromechanical) intervention. The antenna is designed to be part of the command radio line equipment for receiving and transmitting telemetry information in digital format with high-speed flying objects that can rotate around the longitudinal axis and change their polarization during flight. [ABSTRACT FROM AUTHOR]

Using a method based on mathematical operations with Maxwell's equations in vector form, it is proved that electromagnetic waves propagating in an arbitrary direction in a bi-gyrotropic medium are always characterized by the collinear orientations of the Poynting vector and the group velocity vector. It is shown that the corresponding Cartesian components of these vectors are proportional to each other, which confirms the collinearity of these vectors. It is found that for all types of electromagnetic waves propagating in an unbounded ferromagnetic medium (which is a special case of a bi-gyrotropic medium), these vectors are always codirected. [ABSTRACT FROM AUTHOR]

Background. The using of mirror asymmetric chemical compounds for doping quartz makes it possible to metamaterial creation that has the chirality property. In such a compositional structure, unusual effects may arise when interacting with an optical wave. Aim. We calculate the transmission and reflection of a linearly polarized optical wave through a multilayer structure consisting of two doped quartz glasses separated by two air gaps. Methods. Based on a homogeneous mathematical model of a chiral metamaterial, taking into account the dispersion of the dielectric constant and the chirality parameter based on the matrix method, a system of linear algebraic equations is obtained for the complex reflection and transmission coefficients of an electromagnetic wave of linear polarization. Results. An analysis of the frequency and angular characteristics of the modules of the reflection and transmission coefficients was carried out at various values of the quartz doping level. It is theoretically predicted that at some wavelengths, most of the incident optical energy can be concentrated in the air gaps of the multilayer structure. Conclusion. The data obtained as a result of calculations can be used in the development of planar structures for frequency-selective concentration of energy in the visible and infrared spectrum based on quartz glasses doped with chiral chemical compounds.

The article provides a theoretical analysis of the interaction of dual-frequency and modulated electromagnetic waves with anisotropic media above hydrocarbon deposits and computer modeling. The frequency range of changes in the electrodynamic parameters of the environment above the deposit with the manifestation of anomalies in the electric field strength has been established. Recommendations are given for the use of modulated signals to improve the accuracy of determining the boundaries of hydrocarbons based on measuring the phase characteristics of the surface impedance of the medium above the hydrocarbons. A hardware and software complex has been developed for recording the electric field strength in the modes of receiving probing signals and the natu ral radiation of hydrocarbon deposits. Experimental studies were carried out in gas fields of Syria. Methods are shown to increase the information content of the developed method and equipment when carrying out prospecting work at hydrocarbon sites. The research results can be used in devices for identifying oil and gas deposits in geophysics.

Abstract The United Nations focuses on 17 urgent problems to call for action in all countries. Goal 7 of the 17 urgent problems is based on affordable and clean energy. Since 2017, National Taitung University (NTTU) has dedicated more time and effort to attain the wisdom, health, sustainability and aesthetics as an international green university. To accomplish this, we adhere and construct a safe radiofrequency and electromagnetic wave environment to achieve healthy and sustainable campus objectives. According to the UI GreenMetric World University Rankings, NTTU was ranked 74th in 2021, 67th in 2022 and 58th in 2023. In this study, we propose a formal estimation of wireless network services for classrooms or smart spaces to achieve the goal of safe radiofrequency and electromagnetic waves. Inside classrooms or smart spaces, better wireless signal strength and safer electromagnetic waves are achieved. Moreover, the proposed method can be used to determine the quantity of wireless access points for a given classroom or smart space to avoid unsafe electromagnetic waves and inappropriate energy consumption. The experimental results show that all benchmarks meet the wireless exposure limits of the WHO and physician safe technologies in the NTTU.

Comprehensive Summary: The utilization of rare earth (RE) elements is pivotal in wave absorption. In particular cases, RE group elements manifesting unique 4f electron layer structures are doped as impurities into certain materials, which is a practical and reliable method for regulating these materials' magnetic and electrical properties. Moreover, ferrites and metal‐organic frameworks (MOFs), standing out among conventional and emerging wave‐absorbing materials, can achieve significantly enhanced wave absorption through RE doping or substitution. Numerous scholars have dedicated massive research over a substantially long time to explore the utilization of RE elements to reinforce the absorption of these two materials. Therefore, consolidating and summarizing such efforts are crucial and necessary. This review aims to clarify the underlined mechanism of electromagnetic wave (EMW) absorption and elaborate on the impact of RE doping by providing a comprehensive overview of recent progress in ferrites and MOFs dopped with RE elements. Finally, the limitations associated with RE doping in such materials are delineated, and the upcoming prospects for its application are highlighted. Key Scientists: In 1947, J. A. Marinky et al. obtained promethium from uranium fission products. From the isolates of yttrium soil in 1794 to the discovery of promethium in 1947, it took more than 150 years. In 1975, Guangxian Xu found that the rare earth solvent extraction system has the basic "constant mixed extraction ratio" rule. In 1984, the theory of "one‐cavity multi‐mode" was proposed by Weigan Lin to improve the electromagnetic wave theory further and develop the theory of absorbing materials. In 1995, Omar M. Yaghi synthesized the first MOFs in history, and since then, they have been widely used in gas adsorption and separation and other fields because of their large specific surface area and adjustable pore structure. In recent years, various functional materials based on MOFS‐derived carbon have been studied endlessly. Masato Sagawa, known for inventing NdFeB magnets, won the "28th Japan Prize" in 2012. In recent years, Renchao Che has promoted the development of interface theory and magnetic theory in the field of wave absorption. In addition, Jiurong Liu is committed to developing various wave‐absorbing materials and the respective theoretical research and continues to promote the development of wave‐absorbing materials to "thin, light, wide and strong". [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The utilization of rare earth (RE) elements is pivotal in wave absorption. In particular cases, RE group elements manifesting unique 4f electron layer structures are doped as impurities into certain materials, which is a practical and reliable method for regulating these materials' magnetic and electrical properties. Moreover, ferrites and metal‐organic frameworks (MOFs), standing out among conventional and emerging wave‐absorbing materials, can achieve significantly enhanced wave absorption through RE doping or substitution. Numerous scholars have dedicated massive research over a substantially long time to explore the utilization of RE elements to reinforce the absorption of these two materials. Therefore, consolidating and summarizing such efforts are crucial and necessary. This review aims to clarify the underlined mechanism of electromagnetic wave (EMW) absorption and elaborate on the impact of RE doping by providing a comprehensive overview of recent progress in ferrites and MOFs dopped with RE elements. Finally, the limitations associated with RE doping in such materials are delineated, and the upcoming prospects for its application are highlighted. Key Scientists: In 1947, J. A. Marinky et al. obtained promethium from uranium fission products. From the isolates of yttrium soil in 1794 to the discovery of promethium in 1947, it took more than 150 years. In 1975, Guangxian Xu found that the rare earth solvent extraction system has the basic "constant mixed extraction ratio" rule. In 1984, the theory of "one‐cavity multi‐mode" was proposed by Weigan Lin to improve the electromagnetic wave theory further and develop the theory of absorbing materials. In 1995, Omar M. Yaghi synthesized the first MOFs in history, and since then, they have been widely used in gas adsorption and separation and other fields because of their large specific surface area and adjustable pore structure. In recent years, various functional materials based on MOFS‐derived carbon have been studied endlessly. Masato Sagawa, known for inventing NdFeB magnets, won the "28th Japan Prize" in 2012. In recent years, Renchao Che has promoted the development of interface theory and magnetic theory in the field of wave absorption. In addition, Jiurong Liu is committed to developing various wave‐absorbing materials and the respective theoretical research and continues to promote the development of wave‐absorbing materials to "thin, light, wide and strong". [ABSTRACT FROM AUTHOR]

Recently, metasurface‐based photodetectors (metaphotodetectors) have been developed and applied in various fields. Metasurfaces are artificial materials with unique properties that have emerged over the past decade, and photodetectors are powerful tools used to quantify incident electromagnetic wave information by measuring changes in the conductivity of irradiated materials. Through an efficient microstructural design, metasurfaces can effectively regulate numerous characteristics of electromagnetic waves and have demonstrated unique advantages in various fields, including holographic projection, stealth, biological image enhancement, biological sensing, and energy absorption applications. Photodetectors play a crucial role in military and civilian applications; therefore, efficient photodetectors are essential for optical communications, imaging technology, and spectral analysis. Metaphotodetectors have considerably improved sensitivity and noise‐equivalent power and miniaturization over conventional photodetectors. This review summarizes the advantages of metaphotodetectors based on five aspects. Furthermore, the applications of metaphotodetectors in various fields including military and civil applications, are systematically discussed. It highlights the potential future applications and developmental trends of metasurfaces in metaphotodetectors, provides systematic guidance for their development, and establishes metasurfaces as a promising technology. [ABSTRACT FROM AUTHOR]

The combination of 3D printing, polymer derived ceramics, and electromagnetic wave (EMW) absorption metamaterials is particularly useful for spacecraft stealth in extreme environments and is gradually gaining significant interest. While the 3D printing of SiOC has been extensively researched, the high temperature stability and mechanical performance of SiOC are not as favorable as SiCN. However, it remains challenging to prepare SiCN metamaterials with both high mechanical and microwave absorption properties by 3D printing. Herein, we demonstrate a SiCN EMW absorption metamaterial with high mechanical properties using digital light processing 3D printing, which achieves a minimum reflection loss of −31.01 dB (99.9 % absorption), and the widest effective absorption bandwidth covers the entire X-band from 8.2 to 12.4 GHz. And the EMW absorption performance can be adjusted based on the size of the unit structure. [ABSTRACT FROM AUTHOR]

This study proposes a differential wavelength measurement method based on the electromagnetic-induced photoacoustic effect. The differential method involves irradiating the sample with multiple wavelengths and utilizing differences in absorption characteristics across different materials to calculate and measure the excitation light wavelengths. Compared to traditional detection methods, this approach combines the unique properties of electromagnetic-induced photoacoustic effect, offering high sensitivity and a wider detection range from microwave to light. Furthermore, the system is structurally simple and stable, suitable for non-destructive testing of various materials, including wavelength-sensitive biological tissues. The experimental results demonstrate that combined with Polymers Benzodithiophene Triazole–Quinoxaline (PBTQ) and Single-Walled Carbon Nanotubes (SWCNTs) as absorbing media, this technique provides a rapid and cost-effective means of wavelength measurement, achieving an uncertainty of approximately 2.33 nm within the range of 680–800 nm, and it can be used for wavelength/frequency measurement of various electromagnetic waves. [ABSTRACT FROM AUTHOR]

Driven by the scientific objective of geophysical field detection and natural hazard monitoring from space, China launched an electromagnetic satellite, which is known as the China Seismo-Electromagnetic Satellite (CSES-01), on 2 February 2018, into a circular sun-synchronous orbit with an altitude of about 507 km in the ionosphere. The CSES-01 has been in orbit for over 6 years, successfully exceeding its designed 5-year lifespan, and will continually operate as long as possible. A second identical successor (CSES-02) will be launched in December 2024 in the same orbit space. The ionosphere is a highly dynamic and complicated system, and it is necessary to comprehensively understand the electromagnetic environment and the physical effects caused by various disturbance sources. The motivation of this report is to introduce the typical electromagnetic waves, mainly in the ELF/VLF band (i.e., ~100 Hz to 25 kHz), recorded by the CSES-01 in order to call the international community for deep research on EM wave activities and geophysical sphere coupling mechanisms. The wave spectral properties and the wave propagation parameters of those typical EM wave activities in the upper ionosphere are demonstrated in this study based on wave vector analysis using the singular value decomposition (SVD) method. The analysis shows that those typical and common natural EM waves in the upper ionosphere mainly include the ionospheric hiss and proton whistlers in the ELF band (below 1 kHz), the quasiperiodic (QP) emissions, magnetospheric line radiations (MLR), the falling-tone lightning whistlers, and V-shaped streaks in the ELF/VLF band (below 20 kHz). The typical artificial EM waves in the ELF/VLF band, such as power line harmonic radiation (PLHR) and radio waves in the VLF band, are also well recorded in the ionosphere. [ABSTRACT FROM AUTHOR]

Copyright of Natural Gas Industry is the property of Natural Gas Industry Journal Agency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Metasurfaces are two-dimensional artificial structures with numerous subwavelength elements arranged periodically or aperiodically. They have demonstrated their exceptional capabilities in electromagnetic wave polarization manipulation, opening new avenues for manipulating electromagnetic waves. Metasurfaces exhibiting electrically controlled reconfigurable polarization manipulation have garnered widespread research interest. These unique metasurfaces can dynamically adjust the polarization state of electromagnetic waves through real-time modification of their structure or material properties via electrical signals. This article provides a comprehensive overview of the development of metasurfaces exhibiting electrically controlled reconfigurable polarization manipulation and explores the technological advancements of metasurfaces with different transmission characteristics in the microwave region in detail. Furthermore, it delves into and anticipates the future development of this technology.

Background. Taking into account temperature, soil composition, surface roughness and the dependence of effective dielectric constant on frequency allows a more accurate assessment of soil moisture and other important parameters, which can be used in various fields such as agriculture, geology, ecology and hydrology. Aim. In this work, we calculate the reflection of a linearly polarized electromagnetic wave from wet soil, taking into account such physical factors as heterogeneity of soil structure, surface roughness and dispersion. Methods. Based on a heterogeneous mathematical model of wet soil, taking into account the dispersion of the dielectric constant of water and surface roughness, expressions are derived for the complex reflection coefficients of electromagnetic waves of vertical and horizontal polarization. Results. The model of loose wet soil with the standard deviation of roughness on the surface was chosen as the object of study. An analysis of the frequency and angular characteristics of the modules of the reflection coefficients was carried out at a fixed level of soil moisture. Conclusion. The data obtained as a result of the calculations is a valuable tool for further improving methods of remote sensing of the Earth and contributes to the development of new technologies for monitoring soil parameters using unmanned aerial vehicles, which opens up prospects for more accurate and efficient analysis of the state of land resources and ecosystems.

Carbon, one of the most abundant elements in nature, is fundamental to many essential life processes. Among its various nanostructures, carbon nanotubes (CNTs), which are cylindrical in shape, are particularly notable. Single-walled carbon nanotubes (SWCNTs) typically have diameter of approximately 2 nm and length up to 100 μm. These nanotubes exhibit a variety of physicochemical properties, making them promising fillers for polymer composites. In this study, polydimethylsiloxane (PDMS) composites reinforced with carbon nanotubes were investigated. The structure and morphology of these polymer composites were studied and their efficiency in absorbing electromagnetic radiation was assessed. Our research findings indicate that the carbon nanotube/PDMS composites achieve an electromagnetic radiation absorption efficiency of less than 90% in the range of 0.5–6 GHz which includes: TV broadcasting, GSM, WIFI, 3G, 4G, and 5G irradiation ranges. [ABSTRACT FROM AUTHOR]

This study aims to develop a damage-detection algorithm based on the electromagnetic wave properties inside a reinforced concrete structure. The proposed method involves employing two algorithms based on data measured using ground-penetrating radar—a common electromagnetic wave method in civil engineering. The possible defect area was identified based on the energy dissipated by the damage in the frequency-wavenumber domain, with the damage localized using the calculated relative permittivity of the measurements. The proposed method was verified through a finite difference time-domain-based numerical analysis and a testing slab with artificial damage. As a result of verification, the proposed method quickly identified the presence of damage inside the concrete, especially for honeycomb-like defects located at the top of the rebar. This study has practical significance in scanning structures over a large area more quickly than other non-destructive testing methods, such as ultrasonic methods. [ABSTRACT FROM AUTHOR]

The negative effects of continuous exposure to electromagnetic waves know a continuous growth on the last years because of new developments in electronics and mobile communication applications in different fields (medical, smart devices for IoT applications). There are some researches concluding that exposure to electromagnetic fields could affect the cells (PMBCs, T lymphocytes, B lymphocytes, NK cells and macrophages) of the immune system including cell proportion, cell cycle, apoptosis, destruction activity and cytokine content. Considering the negative effect of electromagnetic inference, it is necessary to develop advanced materials to attenuate electromagnetic waves to protect electronic equipment and humans. In this context, this paper presents an experimental plan based on completely randomized blocks (RCBD) for obtaining adequate textile coating for electromagnetic shielding applications taking into account the design of electromagnetic shielding devices should include the modelling of the attenuation phenomenon of electromagnetic waves using Schelkunoff and Calculation theories. The proposed experimental plan consists of experiments distributed in blocks, each block corresponding to the technology used. For each experimental block, the factors specific to the technology used (independent variables such as the metals used (Ni, Cu, graphite, Fe3O4, Ag, Zn), mass (M), air permeability (Pa), thickness (d)) that could influence the response variable (electrical resistance (Rs)) have been taken into consideration. [ABSTRACT FROM AUTHOR]

Actin, a cytoskeletal protein, has a molecular weight of 42 kDa and both monomeric (G-actin) and polymeric (F-actin) structures exist in cells. Polymerization-depolymerization of actin occurs more frequently than for other cytoskeletal proteins such as microtubules and intermediate filaments, and has a significant impact on cell morphology and motility. Actin and some actin-binding proteins are known to be oxidized by reactive oxygen species (ROS), and the regulation of polymerization-depolymerization is affected by the state of oxidation. Recently, it has been increasingly reported that electromagnetic waves such as UV, visible light, near-infrared light, and X-rays induce the generation of intracellular ROS and actin oxidation, leading to polymerization or depolymerization of actin. Furthermore, attempts are being made to control intracellular actin by combining photosensitizers and electromagnetic waves. Since actin is thought to be involved in many diseases, including cancer, these methods have potential medical applications. This review will provide an overview of advances in this field and discuss the prospects for medical applications of methods to control actin polymerization using optical approaches. [ABSTRACT FROM AUTHOR]

Hierarchical-porous-structured materials have been widely used in the field of electromagnetic wave (EMW) absorption, playing a critical role in minimizing EMW interference and pollution. High-quality EMW absorbers, characterized by a lower thickness, lighter weight, wider absorption band, and stronger absorption capacity, have been instrumental in reducing damage and preventing malfunctions in the automotive and aviation industries. The utilization of discarded nut shells through recycling can not only alleviate environmental problems but relieve resource constraints. Herein, a facile method for the preparation of hierarchical porous biomass carbon derived from abandoned Xanthoceras Sorbifolium Bunge Shell (XSS) biomass was developed for high-performance EMW absorption. The porous structures of XSS biochar were studied by using different levels of the K2CO3 activator and simple carbonization. The effect of K2CO3 on the EMW parameters, including the complex permittivity, complex permeability, polarization relaxation, and impedance matching, was analyzed. The best EMW absorption performance of the XSS biochar was observed at a mass ratio of activator-to-biomass of 2:1. A minimum reflection loss (RLmin) of −38.9 dB was achieved at 9.12 GHz, and a maximum effective absorption bandwidth (EABmax) of up to 3.28 GHz (14.72~18.0 GHz) could be obtained at a 1.8 mm thickness. These results demonstrated that hierarchical porous XSS carbon was prepared successfully. Simultaneously, the prepared XSS biochar was confirmed as a potential and powerfully attractive EMW-absorbing material. The proposal also provided a simple strategy for the development of a green, low-cost, and sustainable biochar as a lightweight high-performance absorbing material. [ABSTRACT FROM AUTHOR]

The incidence of electromagnetic H-wave on the thin metal layer at the angle of theta is considered, taking into account the dependence of the specularity coefficients on the surfaces of the thin layer q1 and q2 on the angle of incidence of electrons. The behavior of reflection, transmission and absorption coefficients depending on the thickness of the thin layer is analyzed. The obtained results are compared with experimental data. [ABSTRACT FROM AUTHOR]

Heaviside proposed the telegrapher's equations as an alternative to the Maxwell equations. His proposal was groundbreaking and can be considered miraculous. Nothing could be a more accurate solution than this proposal. The following physical properties can be derived from the telegrapher's equations. The telegrapher's equations are represented by a circuit diagram consisting of series and parallel elements. Circuits are known to have steady and transient states. These equations also demonstrate that the electromagnetic waves, which are determined by the existence of an electromagnetic field expressed by partial differential equations, propagate at the velocity of light c. [ABSTRACT FROM AUTHOR]

Abstract Recently, metasurface‐based photodetectors (metaphotodetectors) have been developed and applied in various fields. Metasurfaces are artificial materials with unique properties that have emerged over the past decade, and photodetectors are powerful tools used to quantify incident electromagnetic wave information by measuring changes in the conductivity of irradiated materials. Through an efficient microstructural design, metasurfaces can effectively regulate numerous characteristics of electromagnetic waves and have demonstrated unique advantages in various fields, including holographic projection, stealth, biological image enhancement, biological sensing, and energy absorption applications. Photodetectors play a crucial role in military and civilian applications; therefore, efficient photodetectors are essential for optical communications, imaging technology, and spectral analysis. Metaphotodetectors have considerably improved sensitivity and noise‐equivalent power and miniaturization over conventional photodetectors. This review summarizes the advantages of metaphotodetectors based on five aspects. Furthermore, the applications of metaphotodetectors in various fields including military and civil applications, are systematically discussed. It highlights the potential future applications and developmental trends of metasurfaces in metaphotodetectors, provides systematic guidance for their development, and establishes metasurfaces as a promising technology.

【Objective】 Soil dielectric constant measures the ability of a soil to transmit electric fields. It is the ratio of the capacitance of a soil sample to the capacitance of air-filled space of the same volume. In this paper, we systematically analyze the factors that influence the dielectric constant, offering an updated perspective on soil dielectric constant modeling. 【Method】 This study systematically identifies the primary factors influencing soil dielectric constant based on soil dielectric theory. Additionally, it categorizes and summarizes existing soil dielectric constant models, facilitating a comparative analysis of their strengths, weaknesses, applications, and future development. 【Result】 The primary influencing factors governing the dielectric constant varied with soil types, with notable dependence on testing frequency. However, the dielectric constant remains a valuable indicator of soil water content. The soil dielectric constant models were broadly categorized into four types: theoretical, semi-empirical, empirical, and boundary models. 【Conclusion】 Presently, there is a dearth of research focusing on the dielectric properties and model development specific to regional soils. Enhancing model accuracy necessitates incorporating the influence of soil-phase composition, mineral composition, and microstructure on the dielectric constant. This refinement will broaden the application studies for assessing and analyzing soil physical and chemical properties based on dielectric constant testing.

So far, various natural and synthetic compounds have been used to treat and control parasites and their diseases, but now researchers have turned to mechanical and physical methods. This study aimed to review and categorize studies in which non-ionizing electromagnetic waves were used to control or treat human parasites. A systematic search was conducted. All English or full Persian articles on the investigation of electromagnetic waves on worms (Helminths) and protozoan parasites worldwide (from 1970 to 2023) indexed in Google Scholar, Science Direct, PubMed, Scopus, Medline, Medlib, Scientific Information Database, ProQuest, IranMedex, IranDoc, Embase and Magiran were collected and reviewed. Finally, 53 articles were included in the study. Its information was extracted and organized in tables based on the kind of non-ionizing wave. The results of this study categorized the information obtained from the articles based on the type of non-ionizing waves and parasites. The findings of this study may serve as a guide for researchers as they create and execute future studies. This review study exposed the capability of non-ionizing electromagnetic waves to inactivate, control and treat parasitic diseases. This review revealed gaps in this field of study, and a road map was provided to design and implement new projects.

Metasurface with programmable configurations has attracted tremendous attention due to their exotic abilities to manipulate electromagnetic waves. Herein, an electrically reconfigurable metasurface for frequency selective transmission is developed based on ionic polymer–metal composite (IPMC) kirigami. First, low‐voltage driven IPMC actuators with stable actuation performance are realized, and then a thermomechanical equivalent model and a numerical electromagnetic analysis model are proposed for evaluating the deformation of the IPMC actuators and predicting the electromagnetic tunable properties of the IPMC kirigami metasurfaces, respectively. Subsequently, large‐area IPMC kirigami metasurfaces are proposed and produced by using programmable nanosecond laser micro‐processing technique that endows the uniformity of the kirigami units. Finally, the electromagnetic functionalities of these IPMC kirigami metasurfaces are researched and validated by experiments and numerical simulations. Both theoretical and experimental results demonstrate that the electromagnetic transmission frequency of the fabricated IPMC kirigami metasurface with 10 × 10 units can be tuned from 19.3 to 20.8 GHz by the application of a low voltage of 3 V. Compared with the existing reconfigurable metasurfaces, the proposed IPMC kirigami metasurface demonstrates clear advantages in its compact structure, lower driving‐voltage, low‐acoustic noise, and wide working frequency range. [ABSTRACT FROM AUTHOR]

The persistently unsolved Abraham–Minkowski controversy (A-MC) is usually associated with division of the total energy–momentum density tensor into electromagnetic and material components. In this work, characteristics of energy and momentum of electromagnetic waves in free space, lossless and lossy media are, respectively, addressed non-relativistically based on conservation or continuity equations. Combining progress of relativistic studies on A-MC and related topics, we demonstrate that, comparing with the treatment of dividing total momentum into electromagnetic and material components, to self-consistently describe properties of both electromagnetic energy and momentum, it is more favorable to take the electromagnetic wave arising in media as a natural whole, i.e., both energy and momentum are no longer to be divided into electromagnetic and material components. This work may be useful to properly describe energy and momentum of electromagnetic waves in media, find reasonable solution of A-MC, and further develop theory of electrodynamics of moving media. [ABSTRACT FROM AUTHOR]

To investigate a thin layer, we conducted borehole radar measurements at the GPR facility of Tohoku University, Japan. Both zero-offset profiling and tomography measurements were used to obtain water content distributions. Analyzing first arrival times with amplitudes, we found that a borehole radar can detect velocity changes caused by a high-water content, which acts as an electromagnetic waveguide. We conducted a 3D FDTD simulation and confirmed that the EM wave propagates as a guided wave in a thin layer related to antenna frequency. We determined a thin geological layer compared to an antenna frequency that cannot be detected by reflection measurement due to the poor radar resolution. By comparing the simulated data with measurement data, we could determine the geological boundary between host layers and a thin layer with high water content. In contrast, both the amplitude and the travel time of direct waves are affected by antenna positions and electrical parameters, including permittivity and conductivity. A vertical velocity profile was obtained by combining complementary zero-offset profiling and tomography data, which can be used to investigate water content distribution. The low-velocity thin layer was characterised by amplitude attenuation and late arrival time. [ABSTRACT FROM AUTHOR]

Objective To investigate the effect of electromagnetic wave power density on the expression of glial fibrillary acidic protein ( GFAP) in the hippocampus of SD rats under 1 800 MHz electromagnetic wave irradiation, and whether it exhibits a “window effect”. Methods Ninety-eight 4-week-old SPF-grade SD rats were randomly divided into 14 groups, with 7 rats in each group. Seven groups were exposed groups (frequency：1 800MHz, power densities: 0.1 mW/cm², 0.3 mW/cm², 0.5 mW/cm², 0.7 mW/cm², 0.9 mW/cm², 1.0 mW/cm², 1.2 mW/cm²) and corresponding 7 groups were control groups (power density: 0 mW/cm²) . Exposure was conducted for 12 hours daily for 3 weeks. After exposure, Western Blot was used to detect the expression level of GFAP in the hippocampal tissue, and immunohistochemistry staining was performed to determine the average optical density (MOD) value of GFAP-positive expression products in the DG, CA3, and CA1 regions of the hippocampal tissue, to determine the power density window of GFAP expression in the hippocampus of SD rats under 1 800 MHz exposure. Results At power densities of 0.1 mW/cm² and 0.3 mW/cm², Western Blot results showed increased expression of GFAP in the rat hippocampus (P < 0.05), and immunohistochemistry staining demonstrated increased MOD values of GFAP in the three regions (P< 0.05). Conclusion Long-term exposure to 1 800 MHz electromagnetic radiation has a “window effect” on the expression of GFAP in the DG, CA3, and CA1 regions of the hippocampus in SD rats, with power density windows of 0.1 mW/cm² and 0.3 mW/cm². [ABSTRACT FROM AUTHOR]

Emerging issues on electromagnetic interference (EMI) caused by blooming of new electronic gadgets and its implementation in different sectors. Thus, the minimization or to control the effect EMI on electronic devices and the designing of stealth equipment requires special attention for dielectric materials of different blends. To modify the dielectric properties of any material, it requires combination of more than one compatible constituent. The designing of hybrid composite with optimum wt.% contributes good dielectric substrate for interaction with the microwave. The thin layer with 3 mm thickness hybrid composite of banana stem and rice husk dust (BAN/RH) with particle size 150 μm in ratio 50–50 wt.% has been synthesized for X-band testing specimen. The results of microwave properties with reflection loss − 14.01 dB attenuates 96.02% of incident power of EM wave significantly describes the importance of dielectric properties of single layer hybrid composite material in X-band frequency range. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Current physics is considered to be based on Newtonian mechanics. The existence of electromagnetic waves was demonstrated by the Maxwell equations. It is also possible to assume that the constitution of electromagnetic waves forms the fundamental principles of physics, including the composition of materials. To demonstrate this assumption, we introduced electromagnetic waves in coaxial cables and determined the propagation constant of these waves, as reported in this Session. The result showed that the real part of the propagation constant, known as the attenuation constant, can be set to zero. In this case, by expressing the variable of the electromagnetic waves as angular frequency («), it is possible to treat the variable of the function as an angle (in radians). As a consequence, we are able to introduce a mathematical representation of phase (neighborhood and metric) for electromagnetic waves. Thus, we demonstrate that the mathematical representation of electromagnetic waves is possible. [ABSTRACT FROM AUTHOR]

Ionic liquid is increasingly being used as a chemical modulator of multi‐walled carbon nanotubes (MWCNT). Here, we report the practical method for producing biodegradable electromagnetic interference (EMI) shield films made of thermoplastic polyurethane (TPU), polybutylene adipate‐co‐terephthalate (PBAT), and 1‐(2‐aminoethyl)‐3‐methyl‐1H‐imidazol‐3‐ium modified MWCNT (MIL). The field emission scanning electron microscopy study of cryo‐fractured 50:50 PBAT/TPU blend giving co‐continuous morphology and subsequent polymer EMI shield nanocomposite material had shown the co‐continuous nanofiller distribution. The nanoparticles were chosen to be distributed in the PBAT portion, according to subsequent research employing HRTEM and DMA. The electrical percolation threshold (EPT) is determined to be situated within 1–3 wt% of nanoparticles loading as the remarkable shift in total EMI shielding efficiency from −14.6 dB (for 1 wt%) to −28.6 dB (for 3 wt%) of nanoparticle‐loaded film at 10 GHz (in X‐band region) for a 0.8 mm thick film reveals that the EPT is approximately at 2 wt% of nanoparticle loading. The effective EMI shielding of −37.3 dB was achieved by 10 wt% of MIL loading. [ABSTRACT FROM AUTHOR]

Metamaterial-based microwave absorbers and sensors are challenging and promising topics for scientists and engineers. In this work, we categorically review microwave absorption mechanisms, different simulation techniques, various types of metamaterial-based microwave absorber and sensor structures, and factors affecting the microwave absorption. This review provides an overall summary of the state-of-the-art progress on various promising and interesting metamaterial absorbers (MTMA) and sensors. Finally, some new prospects are highlighted on advanced MTMA and sensors from theoretical and experimental results. [ABSTRACT FROM AUTHOR]

This paper proposes a method to reduce phantom shell effects that occur during the absorbed power density (APD) derivation using a negative permittivity material (NPM). In this study, APD is examined as a primary parameter to assess the effectiveness of the proposed method, especially following the introduction of APD above 6 GHz, in accordance with 2020 ICNIRP guidelines. As the frequency increases, the impact of the phantom shell can affect APD measurement results. To investigate this, a dipole antenna operating in the $6\sim 10$ GHz frequency range was used as the radiation source. Therefore, this study proposes a method to reduce effects by using NPM. The selection of the NPM is achieved through input impedance calculations method. Simulation results indicate that before applying the proposed method, the APD difference between the presence and absence of the phantom shell ranged from 20.6% at 6 GHz (W/ shell =100, W/o shell =82.9 W/m2) to 69.3% at 10 GHz (W/ shell=52.3, W/o shell=30.9 W/m2). After applying the method, these differences reduced to 6.9% at 6 GHz (proposed method=77.2, W/o shell=82.9 W/m2) and 13.5% at 10 GHz (proposed method=35.1, W/o shell=30.9 W/m2). This study is the first to highlight the impact of phantom shell effects on APD, revealing potential overestimations in the 6-10 GHz range and suggesting that these effects may worsen at higher frequencies. The proposed method effectively addresses these issues within current standards while providing insights for future standards development in higher frequency bands.

In this work, a noninvasive vein finder based on a tuned microwave loop resonator has been demonstrated to locate the vein in a cost-effective, reliable, and convenient way, addressing the challenges in venipuncture, especially in cases of difficult venous access. The sensor is a tuned loop resonator with a radius of 4.7 mm, incorporating a self-tuning pad and operating at 3.25 GHz with a reflection coefficient of $-$58 dB. It provides localized high-intensity electric fields that penetrate into tissues with sufficient depths. The sensor is based on the detection of electromagnetic resonant frequency shift that is susceptible to the distinctive dielectric properties of blood vessels inside the skin. The extensive simulations and experimental measurements on male and female subjects validate its effectiveness with consistent and distinguishable resonant frequency shifts. The sensor's stability across different forearm locations, its ability to differentiate between arteries and veins, and its adherence to safety regulations with low-power microwave signals contribute to its robustness. It shows great promise for improving venipuncture procedures, reducing complications, and enhancing patient comfort in a low-cost and noninvasive way.

Graphite crucibles are widely used in induced crystal growth systems. This study examines the impact of temperature variation on the electrical conductivity of the graphite crucible and its influence on the temperature field and melt flow in a Czochralski germanium crystal growth furnace using the two-dimensional finite element method. The in-depth analysis demonstrates that the temperature-dependence of electrical conductivity of the crucible is crucial in the growth process and the thermal field of the setup. Specifically, it is noted that temperature changes have a significant effect on the generation and distribution of induction heat, the temperature and melt flow field, the complex shape of the crystal-melt interface, as well as the stress and dislocations in the grown crystal. These findings highlight the intricate relationship between temperature, crucible conductivity, and the dynamics of the crystal growth process, providing insight into the subtle factors that impact the quality and properties of the resulting crystal.

This study proposes a differential wavelength measurement method based on the electromagnetic-induced photoacoustic effect. The differential method involves irradiating the sample with multiple wavelengths and utilizing differences in absorption characteristics across different materials to calculate and measure the excitation light wavelengths. Compared to traditional detection methods, this approach combines the unique properties of electromagnetic-induced photoacoustic effect, offering high sensitivity and a wider detection range from microwave to light. Furthermore, the system is structurally simple and stable, suitable for non-destructive testing of various materials, including wavelength-sensitive biological tissues. The experimental results demonstrate that combined with Polymers Benzodithiophene Triazole–Quinoxaline (PBTQ) and Single-Walled Carbon Nanotubes (SWCNTs) as absorbing media, this technique provides a rapid and cost-effective means of wavelength measurement, achieving an uncertainty of approximately 2.33 nm within the range of 680–800 nm, and it can be used for wavelength/frequency measurement of various electromagnetic waves.