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1.
Biomaterials ; 312: 122713, 2025 Jan.
Article in English | MEDLINE | ID: mdl-39084096

ABSTRACT

Traditional bioreactor systems involve the use of three-dimensional (3D) scaffolds or stem cell aggregates, limiting the accessibility to the production of cell-secreted biomolecules. Herein, we present the use a pulse electromagnetic fields (pEMFs)-assisted wave-motion bioreactor system for the dynamic and scalable culture of human bone marrow-derived mesenchymal stem cells (hBMSCs) with enhanced the secretion of various soluble factors with massive therapeutic potential. The present study investigated the influence of dynamic pEMF (D-pEMF) on the kinetic of hBMSCs. A 30-min exposure of pEMF (10V-1Hz, 5.82 G) with 35 oscillations per minute (OPM) rocking speed can induce the proliferation (1 × 105 â†’ 4.5 × 105) of hBMSCs than static culture. Furthermore, the culture of hBMSCs in osteo-induction media revealed a greater enhancement of osteogenic transcription factors under the D-pEMF condition, suggesting that D-pEMF addition significantly boosted hBMSCs osteogenesis. Additionally, the RNA sequencing data revealed a significant shift in various osteogenic and signaling genes in the D-pEMF group, further suggesting their osteogenic capabilities. In this research, we demonstrated that the combined effect of wave and pEMF stimulation on hBMSCs allows rapid proliferation and induces osteogenic properties in the cells. Moreover, our study revealed that D-pEMF stimuli also induce ROS-scavenging properties in the cultured cells. This study also revealed a bioactive and cost-effective approach that enables the use of cells without using any expensive materials and avoids the possible risks associated with them post-implantation.


Subject(s)
Bioreactors , Electromagnetic Fields , Mesenchymal Stem Cells , Osteogenesis , Humans , Mesenchymal Stem Cells/cytology , Mesenchymal Stem Cells/metabolism , Gene Expression Profiling , Cell Proliferation , Cell Differentiation , Cells, Cultured , Transcriptome
2.
J Colloid Interface Sci ; 677(Pt A): 529-539, 2025 Jan.
Article in English | MEDLINE | ID: mdl-39106778

ABSTRACT

Exploring efficient microwave absorbing materials (MAMs) which could convert electromagnetic (EM) energy into thermal energy represents an approbatory vision to reducing EM radiation and interference. Designing of mixed-dimensional structure with multiple interfaces represents the available target to investigate an ideal MAMs, which maximizes the superiority of mixed-dimensional structure in electromagnetic wave absorption (EMWA). Herein, we take full advantage of multiple interfaces engineering of MXene for optimizing the impedance matching to improve EMWA, MXene-based mixed-dimensional structure was designed by incorporating three-dimensional Fe3C@Carbon layers coated zero-dimensional Fe3O4 nanoparticles (NPs) supported two-dimensional MXene nanosheets (MXene/Fe3O4@Fe3C@Carbon, MFC). The Fe3O4@Fe3C@C with Core@shell structure arrests the essentially self-restacked of MXene and provides various attenuation mechanisms for the incident electromagnetic waves (EMWs). By regulating the carbonization temperature, the MFC exhibits enhanced EMWA property which is attributed to the characteristic structure and optimized dielectric-magnetic synergy effect. The minimum reflection loss (RLmin) value of MFC can reach to -64.3 dB with a matching thickness of 1.73 mm. Otherwise, the maximum effective absorption bandwidth (EAB) (RLmin < -10 dB) reaches 6.42 GHz at only 1.5 mm. Thus, our study refers a novel-fire enlighten to develop excellent mixed-dimensional microwave absorbent based on MXene.

3.
Article in English | MEDLINE | ID: mdl-39367812

ABSTRACT

Compared to conventional fibers, electrospun porous nanofibers with hierarchical structures often involve additional active sites, interfaces, and internal spaces which boost the performances of functional materials. Here in this study, coaxial composite cellulose acetate@silk fibroin (CA@SF) fibrous membranes are constructed through an electrostatic spinning technique combining solvent-induced phase separation. Hierarchical core-shell structures on the fibers are achieved, which significantly increases the surface area and benefits the mechanical property, flux, as well as the electroless deposition of Ag nanoparticles. The total electromagnetic shielding efficiency of the sandwiched hierarchical CA@SF@Ag composite membrane with a thickness of only 100 µm reaches up to 100 dB, surpassing around 82% beyond nonhierarchical ones. To be noticed, when post-treated by ethanol, the membrane enables an enhanced tensile strength of up to 10 MPa with a thickness of only 50 µm. Our findings pave the way to the application of electrospun fiber membranes in the field of ultrathin electromagnetic shielding films.

4.
Adv Mater ; : e2410466, 2024 Oct 07.
Article in English | MEDLINE | ID: mdl-39375978

ABSTRACT

High-frequency electronic response governs a broad spectrum of electromagnetic applications from radiation protection, and signal compatibility, to energy recovery. Despite various efforts to manage electric conductivity, dynamic control over dielectric polarization for real-time electromagnetic modulation remains a notable challenge. Herein, an electrochemical lithiation-driven hierarchical disordering strategy is demonstrated for actively modulating electromagnetic properties. The controllable formation and diffusion of coherent interfaces and cation vacancies tailor the coupling of atomic electric field and thus the locally polarized domains, which leads to the reversible electromagnetic transparency/absorption switching with a tunable range of -0.8--20.4 dB for the reflection loss and a broad operation bandwidth of 4.6 GHz. Compared to traditional methods of heteroatomic doping, hydrogenation, mechanical deformation, and phase transition, the electrochemical strategy shows a larger regulation scope of dielectric permittivity with the maximum increase ratios of 260% and 1950% for real and imaginary parts, respectively. This enables the construction of various device architectures including the adaptive window and pixelated metasurface. The results offer opportunities to achieve intelligent electromagnetic devices and pave an avenue to rejuvenate various electromagnetic functions of semiconductive oxides.

5.
Electromagn Biol Med ; : 1-9, 2024 Oct 03.
Article in English | MEDLINE | ID: mdl-39361824

ABSTRACT

The electromagnetic waves of 2.45 GHz microwave frequency have become abundant in environments worldwide. This study assessed the short-term impact of low-intensity 2.45 GHz exposure on young Arabidopsis thaliana plants. The plants underwent a 48-hour exposure to continuous wave 2.45 GHz microwaves at a power density of 1.0 ± 0.1 W m-2. Experiments were conducted inside anechoic chambers. After the microwave exposure samples were subjected to morphological, genotoxicity, pigmentation, and physiochemical analysis. Microwave exposure elevated the levels of photosynthetic pigments, oxidative stress, guaiacol peroxidase activity, and ascorbic peroxidase activity in plants. Conversely, catalase activity decreased. Photosystem efficiency remained unchanged, while non-photochemical quenching increased. Leaf morphological parameters exhibited no significant alterations during this brief exposure period. Notably, despite shifts in physiological parameters and pigmentations, genomic template stability remained unaffected. The findings suggest that the non-thermal effects of microwave exposure influence the photosystem and plant physiology. Research confirmed the existence of non-thermal effects of microwave exposure; however, these effects are within tolerable limits for Arabidopsis thaliana plants.


Microwaves are a category of radio waves with wavelengths ranging from approximately 30 centimeters to one millimeter. The most utilized microwave frequency these days is 2.45GHz, which is used in everyday devices such as microwaves and WiFi signals. This investigation explored the impact of low-intensity 2.45GHz microwaves on young thale cress (Arabidopsis thaliana) plants for 48hours. In other words, research is comparable to scientific assessing how plants respond to the proximity of a 2G WiFi signal. The exposure resulted in increased pigment production in plants and displayed indications of stress, influencing specific plant activities. However, these alterations did not compromise the stability of the genetic materials of the plants. This suggests that although low-intensity microwaves can affect plant systems, the effects appear to be manageable during brief exposures.

6.
Adv Mater ; : e2411248, 2024 Oct 03.
Article in English | MEDLINE | ID: mdl-39363668

ABSTRACT

The rapid development of wearable electronics, personal mobile equipment, and Internet of Things systems demands smart textiles that integrate multiple functions with enhanced durability. Herein, the study reports robust and multifunctional textiles with energy harvesting, electromagnetic interference (EMI) shielding, flame resistance, and Joule heating capabilities, fabricated by a facile yet effective integration method using the deposition of cross-linked MXene (Ti3C2Tx), poly(vinyl alcohol) (PVA), and poly(acrylic acid) (PAA) onto traditional Korean paper, Hanji via vacuum filtration. Comprehensive analyses confirm robust cross-linking, structural integrity, and interface stability in the MXene/PVA/PAA-Hanji (MPP-H) textiles, which synergistically boost their multifunctional performance. The MPP-H textiles exhibit remarkable power generation lasting over 60 min with a power density of 102.2 µW cm-3 and an energy density of 31.0 mWh cm-3 upon the application of 20 µL of NaCl solution. The EMI shielding effectiveness (SE) per unit thickness in the X-band (8.2-12.4 GHz) is up to 437.6 dB mm-1, with the ratio of absorption to reflection reaching 4.5, outperforming existing EMI shielding materials. Superior thermo-chemo-mechanical properties (flame resistance, rapid Joule heating, durability, and washability) further demonstrate their versatile usability. The MPP-H enables diverse functionalities within a single, robust textile through a scalable fabrication method, offering transformative potential for wearable and mobility platforms.

7.
Small Methods ; : e2401299, 2024 Oct 03.
Article in English | MEDLINE | ID: mdl-39363673

ABSTRACT

Structural design and interface regulation are useful strategies for achieving strong electromagnetic wave absorption (EMWA) and broad effective absorption bandwidth (EAB). Herein, a monomer-mediated strategy is employed to control the growth of covalent organic framework (COF) wrapping flower-shaped Gd-doped FeNi3 (GFN), and a novel raspberry-like absorbent based on biomimetic design is fabricated by thermal catalysis. Further, a unique dielectric-magnetic synergistic system is constructed by utilizing the COF-derived nitrogen-doped porous carbon (NPC) as the shell and anisotropic GFN as the core. The electromagnetic parameters of the GFN@NPC composites can be tuned by adjusting the proportions of GFN and NPC. Off-axis electron holography results further clarify the interface polarization and microscale magnetic interactions affecting the EMW loss mechanism. As a result, the GFN@NPC samples exhibit broad EMWA performance. The EAB values of all GFN@NPC composites reach up to 6.0 GHz, with the GFN@NPC-2 sample showing a minimum reflection loss (RLmin) of -69.6 dB at 1.68 mm. In addition, GFN@NPC-2 achieves a maximum radar cross-section (RCS) reduction of 29.75 dB·m2. A multi-layer gradient structure is also constructed using metamaterial simulation to achieve an ultra-wide EAB of 12.24 GHz. Overall, this work provides a novel bio-inspired design strategy to develop high-performance EMWA materials.

8.
Article in English | MEDLINE | ID: mdl-39364552

ABSTRACT

As a novel approach to pursue high-performance multifunctional materials, the structural design of cutting-edge two-dimensional (2D) materials has ignited substantial interests. Borophene, an emerging member in the realm of 2D materials, exhibits crucial attributes, including high theoretical carrier density, electrical conductivity, magnetism, and high aspect ratio, rendering it highly promising for diverse applications. Yet, the exploration of porous structural configurations of borophene remains untapped. Addressing this gap, our study focuses on the fabrication of a multifunctional borophene hybrid foam (CMB-foam). This hybridization leverages the exceptional multifunctionality of MXene alongside borophene within a three-dimensional porous framework, facilitating reflection and absorption of electromagnetic waves, thereby demonstrating remarkable electromagnetic interference (EMI) shielding capabilities. Moreover, this structural configuration exposes an enlarged surface area, thus shortening the transport pathway for electrolyte ions, leading to an excellent energy storage performance. Additionally, CMB-foam performs well in thermal management and thermal insulation. These findings underscore the potential of borophene-based materials in multifunctional applications and offer valuable insights into further performance explorations in this domain.

9.
J Biotechnol Biomed ; 7(3): 387-399, 2024.
Article in English | MEDLINE | ID: mdl-39364330

ABSTRACT

Proliferation and migration of fibroblasts, keratinocytes, and endothelial cells are key events in the physiological process of wound healing. This process includes different but overlapping stages: hemostasis, inflammatory phase, the proliferative phase, and the remodeling phase. Traumatic brain injury (TBI) is defined as a mechanical insult to the brain from external mechanical force (primary injury), usually followed by the secondary injury including edema, inflammation, excitotoxicity, oxidative stress, or mitochondrial dysfunction. The process of tissue repair following TBI is based on the neuronal-glial interactions, where phagocytosis by microglia plays a crucial role. Low-frequency electromagnetic field (LF-EMF) has been shown to enhance tissue repair after TBI, however, there are limited studies investigating the effects of LF-EMF on the proliferation and migration of keratinocytes, fibroblasts, VSMCs, and endothelial cells in the context of wound healing and on neuronal cells and microglia in relation to healing after TBI. Better understanding of the effects of LF-EMF on the proliferation, migration, and differentiation of these cells is important to enhance tissue healing after injury. This review article comprehensively discussed the effect of EMF/LF-EMF on these cells. Results published by different authors are hardly comparable due to different methodological approach and experimental settings. EMF promotes migration and proliferation of fibroblasts, keratinocytes and endothelial cells (EC), and thus could improve wound healing. The pilot study preformed on a large animal model of TBI suggests anti-inflammatory effects of EMF stimulation following TBI. Therefore, EMF is recognized as a potential therapeutic option to accelerate the wound healing and improve cellular recovery and function after TBI. Nonetheless, future studies are needed to define the optimal parameters of EMF stimulation in terms of frequency or duration of exposure.

10.
Cureus ; 16(9): e68487, 2024 Sep.
Article in English | MEDLINE | ID: mdl-39364457

ABSTRACT

Regenerative medicine leverages the body's inherent regenerative capabilities to repair damaged tissues and address organ dysfunction. In orthopedics, this approach includes a variety of treatments collectively known as orthoregeneration, encompassing modalities such as prolotherapy, extracorporeal shockwave therapy, pulsed electromagnetic field therapy, therapeutic ultrasound, and photobiomodulation therapy, and orthobiologics like platelet-rich plasma and cell-based therapies. These minimally invasive techniques are becoming prominent due to their potential for fewer complications in orthopedic surgery. As regenerative medicine continues to advance, surgeons must stay informed about these developments. This paper highlights the current state of regenerative medicine in orthopedics and advocates for further clinical research to validate and expand these treatments to enhance patient outcomes.

11.
Brachytherapy ; 2024 Oct 04.
Article in English | MEDLINE | ID: mdl-39368901

ABSTRACT

PURPOSE: To design, construct, and evaluate a system for image-guided placement of brachytherapy applicators using electromagnetic tracking (EMT) technology for improved procedure quality and efficiency. The system, named EMVision, provides a three-dimensional display of planned needle sites, visibility of the anatomy and needle position during placement, and reference tracking to account for generator or target anatomy shifts. METHODS: The EMVision EMT guidance system registers CT and EMT reference frames using an automated point-based algorithm according to tandem/ovoid locations. Subsequent needle placement and digitization is guided with an intraluminal EMT sensor and user interface that displays the needle's location in axial, coronal, sagittal, and 3D-volumetric CT views. The interface can overlay contours, preplanned needles, and provide 6DOF compensation for tandem movement during needle placement/manipulation. EMVision accuracy was evaluated in phantom and human cadaver by comparing EMVision's DICOM needle positions with a ground-truth, postimplant CT. RESULTS: Proof of concept was demonstrated for EMT-assisted placement of brachytherapy needles. EMVision accuracy in phantom (mean ± standard deviation) on a brachysuite CT table was 0.76 ± 0.13 mm for needle tips placed up to 75 mm from the tandem/ovoids and 0.52 ± 0.27 mm for needle shafts at distances up to 100 mm from the tandem/ovoids. Performance in human cadaver was similar, with tip and shaft accuracies of 0.77 ± 0.14 mm and 0.40 ± 0.21 mm, respectively. CONCLUSION: EMVision provides sub-millimeter accuracy for the placement of brachytherapy needles without repeated or continuous imaging. The technology can be used to reduce brachytherapy procedure times, improve the correspondence between intended and actual needle positions, or decrease the trainee learning curve.

12.
NMR Biomed ; : e5268, 2024 Oct 07.
Article in English | MEDLINE | ID: mdl-39375036

ABSTRACT

Low magnetic field magnetic resonance imaging (MRI) ( B 0 $$ {B}_0 $$  < 1 T) is regaining interest in the magnetic resonance (MR) community as a complementary, more flexible, and cost-effective approach to MRI diagnosis. Yet, the impaired signal-to-noise ratio (SNR) per square root of time, or SNR efficiency, leading in turn to prolonged acquisition times, still challenges its relevance at the clinical level. To address this, researchers investigate various hardware and software solutions to improve SNR efficiency at low field, including the leveraging of latest advances in computing hardware. However, there may not be a single recipe for improving SNR at low field, and it is key to embrace the challenges and limitations of each proposed solution. In other words, suitable solutions depend on the final objective or application envisioned for a low-field scanner and, more importantly, on the characteristics of a specific low B 0 $$ {B}_0 $$ field. In this review, we aim to provide an overview on software solutions to improve SNR efficiency at low field. First, we cover techniques for efficient k-space sampling and reconstruction. Then, we present post-acquisition techniques that enhance MR images such as denoising and super-resolution. In addition, we summarize recently introduced electromagnetic interference cancellation approaches showing great promises when operating in shielding-free environments. Finally, we discuss the advantages and limitations of these approaches that could provide directions for future applications.

13.
Article in English | MEDLINE | ID: mdl-39360334

ABSTRACT

The growing high standard of people's wear has put forward requirements for fabrics, and multifunctional fabrics have been developed precisely in response to the requirements of the times. However, the incineration of waste fabrics produces a large amount of pollutants, resulting in a massive waste of resources and environmental pollution. Herein, the degradable nanofiber yarns (NYs) with self-cleaning properties were fabricated by in situ growth of SiO2 nanoparticles on the surface of the electrospun poly(p-dioxanone) (PPDO) NYs using the Stöber method. Then, the PPDO NYs were blended with carbon fibers and the PPDO/SiO2 NYs with themselves to form the Janus PPDO fabrics, respectively. The Janus PPDO fabric offered asymmetric wettability and dual personal thermal management properties. The PPDO/C side of the Janus PPDO fabric provided 65.8 °C at 1.5 V or 58.5 °C under one sunlight intensity for radiative heating. The PPDO/SiO2 side exhibited high solar reflectivity (81.8%) and mid-infrared (MIR) emissivity (99.1%), which reduced the skin temperature by 4.6 °C, resulting in radiative cooling. Moreover, the Janus PPDO fabrics display an excellent electromagnetic interference (EMI) shielding performance (53.3 dB). Therefore, yarn-based degradable Janus fabric has a promising future in multifunctional wearable products.

14.
Front Med (Lausanne) ; 11: 1445752, 2024.
Article in English | MEDLINE | ID: mdl-39238596

ABSTRACT

Background: Lung cancer associated with cystic airspaces is a rare disease, and a rare imaging performance of non-small cell lung cancer. Due to the lack of conventional diagnosis methods, it is difficult to rely on imaging diagnosis. Therefore, the definitive diagnosis of these neoplastic lesions remains challenging. Case presentation: We summarize the follow-up and diagnosis of a rare cystic airspaces lung metastatic carcinoma in an elderly man with annular density shadow in the right inferior lobe 2 years after surgery for squamous cell carcinoma in the left inferior lobe. Results: During the follow-up of the patient, after the lesion of the lower lobe of the right lung was enlarged, the structural and imaging characteristics were identified, and a special method was selected, namely biopsy of the lesion under the electromagnetic navigation bronchoscope, for clear diagnosis and subsequent treatment. Conclusion: For pulmonary cystic airspaces, it is important to correctly identify their imaging features. Because of the possibility of malignancy, it is essential to stop the radiological study in time and to acquire the pathological diagnosis by an appropriate method.

15.
J Clin Med ; 13(17)2024 Aug 28.
Article in English | MEDLINE | ID: mdl-39274319

ABSTRACT

Background/Objectives: Electroencephalography (EEG) is considered a standard but powerful tool for the diagnosis of neurological and psychiatric diseases. With modern imaging techniques such as magnetic resonance imaging (MRI), computed tomography (CT), and magnetoencephalography (MEG), source localization can be improved, especially with low-resolution brain electromagnetic tomography (LORETA). The aim of this review is to explore the variety of modern techniques with emphasis on the efficacy of LORETA in detecting brain activity patterns in schizophrenia. The study's novelty lies in the comprehensive survey of EEG methods and detailed exploration of LORETA in schizophrenia research. This evaluation aligns with clinical objectives and has been performed for the first time. Methods: The study is split into two sections. Part I examines different EEG methodologies and adjuncts to detail brain activity in deep layers in articles published between 2018 and 2023 in PubMed. Part II focuses on the role of LORETA in investigating structural and functional changes in schizophrenia in studies published between 1999 and 2024 in PubMed. Results: Combining imaging techniques and EEG provides opportunities for mapping brain activity. Using LORETA, studies of schizophrenia have identified hemispheric asymmetry, especially increased activity in the left hemisphere. Cognitive deficits were associated with decreased activity in the dorsolateral prefrontal cortex and other areas. Comparison of the first episode of schizophrenia and a chronic one may help to classify structural change as a cause or as a consequence of the disorder. Antipsychotic drugs such as olanzapine or clozapine showed a change in P300 source density and increased activity in the delta and theta bands. Conclusions: Given the relatively low spatial resolution of LORETA, the method offers benefits such as accessibility, high temporal resolution, and the ability to map depth layers, emphasizing the potential of LORETA in monitoring the progression and treatment response in schizophrenia.

16.
Materials (Basel) ; 17(17)2024 Aug 23.
Article in English | MEDLINE | ID: mdl-39274574

ABSTRACT

The modulation of electrical properties in composite materials is critical for applications requiring tailored electrical functionality, such as electromagnetic shielding and absorption. This study focuses on Ti64/B4C composites, a material combination promising enhanced electromagnetic properties. Laser direct manufacturing (LDM) was utilized to fabricate coaxial samples of Ti64 blended with TiB and TiC in various mass ratios, with sample thicknesses ranging from 0.5 mm to 3.5 mm. The electrical characterization involved assessing the dielectric and magnetic permeability, as well as impedance and reflectance, across a frequency spectrum of 2 to 18 GHz. The result reveals that TiC, when incorporated into Ti64, exhibits strong dielectric polarization and achieves a reflectivity as low as -40 dB between 7 and 14 GHz. Conversely, TiB demonstrates effective electromagnetic absorption, with reflectivity values below -10 dB in the frequency band of 8.5 to 11.5 GHz. The study also notes that a lower B4C content enhances electronic polarization and increases the dielectric coefficient, while higher contents favor ionic polarization. This shift can lead to a timing mismatch in the establishment of electron and ion polarization, resulting in a decreased dielectric coefficient. In addition, adjusting the B4C content in Ti64/B4C composites effectively modulates their electrical properties, suggesting a strategic approach to designing materials for specific electromagnetic functions.

17.
Molecules ; 29(17)2024 Aug 23.
Article in English | MEDLINE | ID: mdl-39274848

ABSTRACT

Developing multifunctional flexible composites with high-performance electromagnetic interference (EMI) shielding, thermal management, and sensing capacity is urgently required but challenging for next-generation smart electronic devices. Herein, novel nacre-like aramid nanofibers (ANFs)-based composite films with an anisotropic layered microstructure were prepared via vacuum-assisted filtration and hot-pressing. The formed 3D conductive skeleton enabled fast electron and phonon transport pathways in the composite films. As a result, the composite films showed a high electrical conductivity of 71.53 S/cm and an outstanding thermal conductivity of 6.4 W/m·K when the mass ratio of ANFs to MXene/AgNWs was 10:8. The excellent electrical properties and multi-layered structure endowed the composite films with superior EMI shielding performance and remarkable Joule heating performance, with a surface temperature of 78.3 °C at a voltage of 2.5 V. Additionally, it was found that the composite films also exhibited excellent mechanical properties and outstanding flame resistance. Moreover, the composite films could be further designed as strain sensors, which show great promise in monitoring real-time signals for human motion. These satisfactory results may open up a new opportunity for EMI shielding, thermal management, and sensing applications in wearable electronic devices.

18.
Sensors (Basel) ; 24(17)2024 Aug 26.
Article in English | MEDLINE | ID: mdl-39275436

ABSTRACT

Amid the rapid advancement of electronic information technology, the need for cable eccentricity measurement in the industry is increasing both in China and across the globe. Current detection methods have several flaws, including high costs, insufficient accuracy, and instability. In this paper, we introduce a magnetic field-based detection method for cable eccentricity that provides high precision and cost-effectiveness. We position three pairs of magnetic field-collection modules in a circular array to gather magnetic flux density information induced by the electrified cable. We apply the law of electromagnetic induction to calculate the cable eccentricity. Our method is non-contact, preserving the cable's integrity. Our method outperforms traditional detection methods, not only in achieving greater accuracy and stability but also in significantly lowering the detection cost. Simulations and experiments show that our method's error rate under specified conditions is 0~4%, with a maximum standard deviation of 0.11, confirming its precision and stability in detecting cable eccentricity. The effectiveness of our method is influenced by two factors: lift-off value and loading current intensity. Our method presents a novel concept and a dependable strategy for the progress of cable eccentricity-detection technology.

19.
Sensors (Basel) ; 24(17)2024 Aug 29.
Article in English | MEDLINE | ID: mdl-39275528

ABSTRACT

The research on MEMS wireless sensing technology adapted to strong power frequency electromagnetic field environments is of great significance to our energy security, economic society, and even national security. Here, we propose a subwavelength cross-meandering resonator (0.49λ0 × 0.49λ0) to simultaneously achieve power frequency electromagnetic field shielding and wireless communication signal transmission. The element size of the resonator is only λ0/11, which is much smaller than that of previous works. In the resonator, a resonance mode with the significant near-field enhancement effect (about 180 times that at f = 1 GHz) is supported. Based on the self-made shielding box experimental setup, the measured shielding effectiveness of the resonator sample can reach more than 33 dB. Moreover, by integrating the cross-meandering resonator with the MEMS sensor, a wireless communication signal can be successfully transmitted. A dual-function cross-meandering resonator integrated with sensors may find potential applications in many military and civilian industries associated with strong power frequency electromagnetic fields.

20.
Sensors (Basel) ; 24(17)2024 Aug 30.
Article in English | MEDLINE | ID: mdl-39275545

ABSTRACT

This study investigates magnetic flux density (B) and radiofrequency electromagnetic field (RF-EMF) measurements on electric buses operating in Samsun, Turkey, focusing on two bus routes (called E1 and E4) during the morning and evening hours. Measurements were taken under diverse operational conditions, including acceleration, cruising, and braking, at locations of peak passenger density. Along the E1 route, the magnetic field intensity varied significantly based on the bus position, road slope, and passenger load, with notable increases during braking. In contrast, the E4 route showed a lower magnetic field intensity and RF-EMF values due to its straighter trajectory and reduced operational stops. The highest RF-EMF measurement recorded was 6.01 V/m, which is below the maximum levels established by the ICNIRP guidelines. In 11 out of the 12 different band-selective RF-EMF measurements, the highest contribution came from the downlink band of the base stations, while in only one measurement, the highest contribution originated from the uplink bands of the base stations. All data were subject to the Anderson-Darling test, confirming the generalized extreme value distribution as the best fit for both B and RF-EMF measurements. Additionally, the study assessed B levels inside and outside the bus during charging, revealing heightened readings near the pantograph. These findings significantly contribute to our understanding of electromagnetic field exposure in electric bus environments, highlighting potential health implications and informing the development of targeted mitigation strategies.

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