Search Results (731)

Underground gas storage (UGS) is critical to national reserves and seasonal peak-shaving, and its safe operation is integral to energy security. In UGS surface process pipelines, heterogeneous bimetal composite pipes—carbon-steel substrates lined with stainless steel—are widely used but susceptible under coupled thermal–pressure–flow loading to geometry-induced instabilities (local buckling, adhesion, and collapse), which can restrict flow, concentrate stress, and precipitate rupture and unplanned shutdowns. Conventional ultrasonic testing and magnetic flux leakage have limited sensitivity to such instabilities, while standard eddy-current testing is impeded by the ferromagnetic substrate’s high permeability and electromagnetic shielding. This study introduces magnetically saturated pulsed eddy-current testing (MS-PECT). A quasi-static bias field drives the substrate toward magnetic saturation, reducing differential permeability and increasing effective penetration; combined with pulsed excitation and differential reception, the approach improves defect responsiveness and the signal-to-noise ratio. A prototype was developed and evaluated through mechanistic modeling, numerical simulation, laboratory pipe trials, and in-service demonstrations. Field deployment on composite pipelines at the Hutubi UGS (Xinjiang, China) enabled rapid identification and spatial localization of liner collapse under non-shutdown or minimally invasive conditions. MS-PECT provides a practical tool for composite-pipeline integrity management, reducing the risk of unplanned outages, enhancing peak-shaving reliability, and supporting resilient UGS operations. Full article

Background: Research on the impact of 5G mobile phone electromagnetic exposure on corticospinal excitability and intracortical mechanisms is still poorly understood. Objective: This randomized controlled pilot study explored the effects of 5G mobile phone exposure at 3.6 GHz (power density: 0.0030 W/m²) on corticospinal excitability and intracortical mechanisms in healthy adults. Methods: Nineteen healthy participants (mean age: 36.5 years) were exposed to 5G mobile phone exposure for 5 and 20 min, approximating the typical duration of a phone call. Corticospinal excitability, intracortical facilitation, short intracortical inhibition, and long intracortical inhibition using single- and paired-pulse transcranial magnetic stimulation assessed before and immediately after exposure were performed. Results: A two-way repeated-measures ANOVA revealed no significant interactions between exposure condition (5 min, 20 min, sham) and time (pre vs. post) for CSE, ICF, SICI, or LICI (all p > 0.15). Bayesian analyses yielded Bayes factors close to 1, indicating inconclusive evidence for both the null and alternative hypotheses. Conclusion: Short-term exposure to 5G mobile phone electromagnetic fields did not produce detectable changes in corticospinal or intracortical excitability. Bayesian evidence was similarly inconclusive (Bayes factors ≈ 1), suggesting that the data provide limited support for either the presence or absence of a detectable effect. Any potential influence of 5G exposure on neural function is therefore likely to be subtle with the present methods. As a pilot study, these findings should be interpreted cautiously and underscore the need for further research using more sensitive outcome measures, extended exposure durations, and vulnerable populations. Full article

Vector hydrophones play an extremely important role in marine exploration. How to reduce the size of vector hydrophones while improving their directional detection capability is a critical issue that needs to be addressed. The auditory organ of the fly Ormia ochracea represents a prime example of achieving high-resolution directional detection within a compact size range. This paper proposes a vector hydrophone that integrates an Ormia ochracea fly-inspired mechanically coupled structure with an optical fiber vibration sensing structure, offering advantages of small size and strong electromagnetic interference immunity. The hydrophone demonstrates a good response to acoustic pulse trains and can accurately demodulate acoustic waves from 1 kHz to 10 kHz. Directional response experiments show that this hydrophone can significantly amplify the time delay differences of incoming acoustic waves. At an acoustic frequency of 9.25 kHz, the time delay amplification factor reaches approximately 50 times within the range of −90° to +90°, exhibiting good cosine directionality. Full article

Several industrial applications rely on induction motors to carry out processes essential for product manufacturing. Speed control of an induction motor commonly requires a pulse width modulated inverter capable of driving a system with long cables, suppression of common mode voltage, reduction in common mode current, and suppression of electromagnetic interference. This paper proposes a three-phase motor drive aimed at maintaining a constant common-mode voltage. The proposed system consists of two three-phase conventional full bridge inverters connected in parallel and having as an input two separate direct current sources. The proposed system is controlled by using the space vector pulse width modulation technique. By properly designing the switching signal sequences for both converters, the common-mode voltage can be maintained constant, thereby reducing the associated common-mode current to an RMS value of $92.3$ mA and enhancing the overall reliability of the system. The proposed system is validated through numerical simulations and by the implementation of an experimental prototype. Full article

Electromagnetically induced transparency (EIT) is well known as a quantum optical phenomenon that permits a normally opaque medium to become transparent due to the quantum interference between transition pathways. This work addresses multi-soliton dynamics in an EIT system modeled by the integrable Maxwell–Bloch (MB) equations for a three-level $\Lambda$-type atomic configuration. By employing a generalized gauge transformation, we systematically construct explicit N-soliton solutions from the corresponding Lax pair. Explicit forms of one-, two-, three-, and four-soliton solutions are derived and analyzed. The resulting pulse structures reveal various nonlinear phenomena, such as temporal asymmetry, energy trapping, and soliton interactions. They also highlight coherent propagation, elastic collisions, and partial storage of pulses, which have potential implications for the design of quantum memory, slow light, and photonic data transport in EIT media. In addition, the conservation of fundamental physical quantities, such as the excitation norm and Hamiltonian, is used to provide direct evidence of the integrability and stability of the constructed soliton solutions. Full article

In this paper, the failure mechanisms and electromagnetic protection design of an electronic switching system under high-power electromagnetic pulse (HPEMP) effects are studied. By integrating experimental testing and modeling simulation methods, the coupling characteristics of HPEMP energy within the electronic switching system, the response characteristics of sensitive components, and their physical failure processes were analyzed. The research indicates that the root cause of system failure under HPEMP irradiation lies in the intrusion of electromagnetic energy coupled through specific anode or gate cable ports, leading to unintended turn-on of the key thyristor device and consequent system functional failure. Mechanism analysis reveals that when the coupled voltage on the thyristor pins exceeds the gate trigger threshold, a carrier regeneration mechanism is activated within the device, resulting in polarity reversal of the PN junction and the formation of a positive feedback path, ultimately causing false triggering. Experimental and simulation results show good consistency in terms of effect thresholds. Based on these findings, effective electromagnetic protection hardening designs targeting the identified electromagnetic vulnerability paths and sensitive components were proposed, and the effectiveness of the protective measures was validated through experiments. Full article

This study examines the contrast in the nonlinear dynamics of Thrinax radiata Lodd. ex Schult. & Schult. f. Seed germplasm explored by optical and electrical signals. By integrating chaotic attractors for the modulation of the optical and electrical measurements, the research ensures high sensitivity monitoring of seed germplasm dynamics. Reflectance measurements and electrical responses were analyzed across different laser pulse energies using Newton–Leipnik and Rössler chaotic attractors for signal characterization. The optical attractor captured laser-induced changes in reflectance, highlighting nonlinear thermal effects, while the electrical attractor, through a custom-designed circuit, revealed electromagnetic interactions within the seed. Results showed that increasing laser energy amplified voltage magnitudes in both systems, demonstrating their sensitivity to energy inputs and distinct energy-dependent chaotic patterns. Fractional calculus, specifically the Caputo fractional derivative, was applied for modeling temperature distribution within the seeds during irradiation. Simulations revealed heat transfer about 1 °C in central regions, closely correlating with observed changes in chaotic attractor morphology. This interdisciplinary approach emphasizes the unique strengths of each method: optical attractors effectively analyze photoinduced thermal effects, while electrical attractors offer complementary insights into bioelectrical properties. Together, these techniques provide a realistic framework for studying seed germplasm dynamics, advancing knowledge of their responses to external perturbations. The findings pave the way for future applications and highlight the potential of chaos theory for early detection of structural and bioelectrical changes induced by external energy inputs, thereby contributing to sample protection. Our results provide quantitative dynamical descriptors of laser-evoked seed responses that establish a tractable framework for future studies linking these metrics to physiological outcomes. Full article

This paper explores the feasibility of implementing a flywheel energy storage system designed to generate voltage for the purpose of mitigating current flow through the transformer neutral path to ground, which is induced by a high-altitude electromagnetic pulse (HEMP) event. The active flywheel system presents the advantage of employing custom optimal control laws, in contrast to the conventional approach of utilizing passive blocking capacitors. A Hamiltonian-based optimal control law for energy storage is derived and integrated into models of both the transformer and the flywheel energy storage system. This Hamiltonian-based feedback control law is subsequently compared against an energy-optimal feedforward control law to validate its optimality. The analysis reveals that the required energy storage capacity is $13\mathrm{Wh}$, the necessary power output is less than $5\mathrm{kW}$ at any given time during the insult, and the required bandwidth for the controller is around $5\mathrm{Hz}$. These specifications can be met by commercially available flywheel devices. This methodology can be extended to other energy storage devices to ensure that their specifications adequately address the requirements for HEMP mitigation. Full article

Approaches to magnetotelluric monitoring of variations in apparent resistivity and electromagnetic emission that may serve as earthquake precursors are considered. Monitoring of apparent resistivity is advised in the range 7–300 Hz, where natural electromagnetic fields exhibit stable behavior, while at lower frequencies the behavior of the electrotelluric and magnetic fields should be analyzed. We present results of studies aimed at identifying active faults and searching for stress–strain sensitive zones for installing measurement equipment based on the registration of tidal variations in apparent resistivity. The features of apparent resistivity anomalies preceding earthquakes in China based on direct current measurements are discussed. Based on the analysis of natural electromagnetic field monitoring in the ULF and ELF ranges in China, the anomalies recorded prior to several recent earthquakes are considered. Before the Yangbi earthquake (2017) and the series of Yangbi (2021) and Ninglang (2022) earthquakes, variations in apparent resistivity were observed that have a pulsed behavior and probably are manifestations of electromagnetic emission. Possible sources of these anomalies are active faults located near the monitoring stations. Full article

Background: Diabetes mellitus is a heterogeneous chronic disease with an increasing global prevalence. In Romania, 11.6% of the population is affected, yet only 6.46% receive treatment. Among diabetic patients, 15–25% develop skin lesions that may progress to ulceration and necrosis, significantly impairing quality of life and increasing the risk of complications. Methods: We conducted a prospective study including 28 patients (14 in the control group and 14 in the intervention group) with type I or II diabetes and chronic ulcers of the calf or foot (>4 cm²). The control group received standard therapy with debridement, dressings, antibiotics when indicated, and local and systemic ozone therapy. The intervention group was treated with an Integrative Therapeutic Protocol combining ozone therapy, pulsed electromagnetic field therapy (PEMF), colon hydrotherapy with probiotic supplementation, and an anti-inflammatory alkaline diet. Wound healing (reduction in ulcer surface area) was the primary endpoint; secondary endpoints included changes in glycemia and inflammatory biomarkers. Results: After 8 weeks, the intervention group achieved 86.2% re-epithelialization versus 58.2% in controls (p < 0.01). Significant improvements were also observed in blood glucose level (−38%), HbA1c (−25%), CRP (−26%), and fibrinogen (−28%) relative to baseline, with differences versus controls reaching statistical significance. Conclusions: The Integrative Therapeutic Protocol accelerated wound healing and improved glycemic and inflammatory profiles compared with ozone therapy alone. Although an alkaline diet was recommended, adherence and its specific contribution were not objectively monitored; therefore, this component should be interpreted with caution. Full article

Peripheral nerve injuries (PNIs) present significant clinical challenges, often leading to severe motor, sensory, and autonomic dysfunction, with profound impacts on patient quality of life and considerable healthcare costs. This review synthesizes current knowledge on the therapeutic potential of Pulsed Electromagnetic Fields (PEMF) and Low-Intensity Pulsed Ultrasound (LIPUS) as non-invasive modalities for promoting peripheral nerve regeneration. We explore their cellular and molecular mechanisms of action, discuss optimal treatment parameters, and present evidence from preclinical and clinical studies, including their synergistic effects with other therapies and emerging applications beyond neurological repair. Clinical studies have shown that PEMF therapy can significantly reduce neuropathic pain and improve functions, whereas LIPUS demonstrates the ability to enhance nerve conduction. Full article

Fermented vegetables, which are valued for their distinctive organoleptic properties and nutritional profile, are susceptible to quality deterioration during processing and storage because microorganisms inhabit vegetable raw materials. The metabolic processes of these microorganisms may induce texture degradation, chromatic alterations, flavor diminution, and spoilage. Conventional inactivation methods employing thermal sterilization or chemical preservatives achieve microbial control through nonselective inactivation, inevitably compromising the regional sensory characteristics conferred by indigenous fermentative microbiota. Recent advances in existing antimicrobial technologies offer promising alternatives for selective microbial management in fermented vegetable matrices. Existing modalities, including cold plasma, electromagnetic wave-based inactivation (e.g., photodynamic inactivation, pulsed light, catalytic infrared radiation, microwave, and radio frequency), natural essential oils, and lactic acid bacterial metabolites, demonstrate targeted pathogen inactivation while maintaining beneficial microbial consortia essential for quality preservation when properly optimized. This paper explores the applications, mechanisms, and targeted microbes of these technologies in fermented vegetable ingredients, aiming to provide a robust theoretical and practical framework for the use of selective inactivation strategies to manage the fermentation process. By assessing their impact on the initial microbial community, this review aims to guide the development of methods that ensure product safety while safeguarding the characteristic flavor and quality of fermented vegetables. Full article

Complex Regional Pain Syndrome (CRPS) type 1 is a painful and disabling localized syndrome with a pathogenesis that is still unclear. The last revised diagnostic criteria for CRPS-1 syndrome were developed in 2012 (the so-called Budapest criteria), based only on clinical features, while the presence of bone marrow edema (BME) and the response to treatments were completely absent. As BME is usually present on magnetic resonance imaging (MRI) in the early (“warm”) phase of CRPS-1, this criterion should be added as a necessary criterion to Budapest criteria. In addition, hyperalgesia and/or allodynia are also commonly present in the warm phase. Therefore, both of these symptoms should be included as essential criteria. Furthermore, the response to bisphosphonates may be another important parameter to add to the list of treatment options, as well as hyperbaric oxygen therapy. Finally, it must be clear that BME is not an exclusive finding of CRPS-1. Therefore, a correct clinical history and, if needed, further radiological studies and laboratory tests should be performed to avoid a false diagnosis. In this paper, the “Bone Marrow Edema Diagnosis and Therapeutic Treatment” Italian Group (GEODEIT) proposes a revision of Budapest’s criteria to make them more meaningful and effective in reaching a correct and quick diagnosis of the disease. Full article

Ground-penetrating radar surveys on structures have a wide range of applications, and they are very useful in solving engineering problems: from detecting reinforcement, studying concrete characteristics, unfilled joints, analyzing brick elements, detecting water content in building bodies, and evaluating structural deformation. They generally pursued small investigation areas with measurements made in direct contact with target structures and for small depths. Detecting deep piles presents specific challenges, and surveys conducted from the ground level may be unsuccessful. To reach great depths, medium-low frequencies must be used, but this choice results in lower resolution. Furthermore, the pile signals may be masked when they are located beneath massive reinforced foundations, which act as an electromagnetic shield. Finally, GPR equipment looks for differences in the dielectric of the material, and the signals recorded by the GPR will be very weak when the differences in the physical properties of the investigated media are modest. From these weak signals, it is difficult to identify information on the differences in the subsurface media. In this paper, we are illustrating an exploration on plinth foundations, supported by drilled piles, submerged in soil, extensive, deep and uninformed. Pulse GPR prospecting was performed in common-offset and single-fold, bistatic configuration, exploiting the exposed faces of an excavation around the foundation. In addition, three velocity tests were conducted, including two in common mid-point and one in zero-offset transillumination, in order to explore the range of variation in relative dielectric permittivity in the investigated media. Thanks to the innovative survey on the excavation faces, it is possible to perform profiles perpendicular to the strike direction of the interface. The electromagnetic backscattering analysis approach allowed us to extract the weighted average frequency attribute section. In it, anomalies emerge in the presence of drilled piles with four piles with an estimated diameter of 80 cm. Full article

This paper deals with an optimal operation method for surge protective devices (SPDs) to calculate the maximum continuous operating voltage (U_C) and the voltage protection level (U_P) by considering the sum of the voltage protection level and the dielectric continuous voltage limit of surge protective devices in order to effectively protect energy storage system (ESS) from switching and lightning surges. This paper also implements a test device for SPDs in ESSs based on the concept of a lightning electromagnetic surge protection measurement system (LPMS) by combining an SPD coordinated with spatial shielding with an ESS configuration. Here, the test device for the SPD in the ESS is composed of a power distribution unit (PDU), uninterruptible power supply (UPS), and a lightning electromagnetic pulse (LEMP) protection device, which combines two units of SPDs and disconnection switches (DSs) connected in parallel with two units of main circuit breakers (MCBs) and noise cut transformers (NCTs) connected in series. From the test results based on the proposed optimal operation method and test device, it is clear that the residual voltage with a third-class combination waveform can be kept within 1.5 kV of the surge voltage limit in all test scenarios, and it is confirmed that the proposed test device for SPDs can protect ESSs from switching and lightning surges. Therefore, it is confirmed that the SPD tested using the proposed method can effectively reduce switching and lightning surges, while the existing SPDs installed in ESS sites cannot protect ESSs from such surges. Full article