Search Results (1,072)

Accurate and reliable current measurement is a key prerequisite for ensuring the safe operation of power systems. Conventional through-core and wound current transformers require power outage for installation or modification of line structures, which are plagued by high installation difficulty and cost, and fail to meet the digital development needs of smart grids. To address the demand for non-intrusive installation of current transformers, this paper proposes a non-intrusive current transformer with PCB coils in reverse-series connection. First, a magnetic coupling current calculation model is established to design a reverse-series double-layer coil structure, and a mathematical model of the equivalent circuit for the sensing and measurement system is constructed. The influence of circuit parameters on the output response is analyzed, yielding an optimization method for the system operating state and completing the hardware circuit design. Subsequently, a simulation model of the reverse-series double-layer coil is built to calculate and analyze the amplitude-frequency characteristics, steady-state and transient performance, as well as anti-interference capability of the transformer. The results demonstrate that the designed transformer, combined with an active integrating circuit, achieves an upper cutoff frequency of 13,169 Hz and a lower cutoff frequency approaching 0 Hz, which satisfies the requirements of wide-frequency measurement while ensuring high sensitivity and anti-interference capability. Finally, a current-sensing experiment platform is built for comparative verification with conventional invasive current transformers. Experimental results show that after correction with a proportional coefficient of 1.317, the fitting squared error is only 0.0038. The linearity remains excellent under different conditions with a wide dynamic measurement range, and the phase error is less than 15°. Within the range of 2–120% of the rated current, the ratio error is less than 0.9%, indicating high measurement accuracy. This study provides a new high-precision and convenient method for current measurement in smart grids. Full article

Background/Objectives: Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect of taxanes and platinum-based agents, impairing quality of life. Duloxetine is the only drug with proven efficacy, but is often limited by tolerability. AT-04 is a portable alternating magnetic field device that activates descending pain modulatory systems and has shown safety in other pain settings. This investigator-initiated trial evaluated the efficacy and safety of AT-04 for persistent CIPN. Methods: We conducted a randomized, double-blind, sham-controlled, multicenter phase II study. Patients with CIPN lasting ≥12 weeks after chemotherapy and pain NRS ≥ 4 were enrolled. Participants used AT-04 or sham devices twice daily for 12 weeks. The primary endpoint was the change in pain NRS on day 85. Secondary endpoints included tingling NRS, numbness NRS, CIPN20 subscales, and safety. Results: Twenty-eight patients were randomized (14 per arm). No significant difference was observed in pain NRS on day 85 {AT-04: −1.74 ± 0.6 vs. sham device: −1.45 ± 0.6; one-sided p = 0.36, effect size (ES) = 0.48}. CIPN20 motor scores improved with AT-04 on days 29 (−9.82 ± 13.8 vs. 0.74 ± 8.7, respectively; p = 0.035, ES = 0.92) and 57 (−11.81 ± 10.6 vs. −0.54 ± 6.7, respectively; p < 0.01, ES = 1.26). Among patients whose last chemotherapy had ended >1 year earlier (n = 16), motor scores improved from days 29 (−12.43 ± 10.3 vs. 2.38 ± 8.9, respectively; p < 0.01, ES = 1.55) to 85 (−11.76 ± 10.1 vs. −0.07 ± 11.5, respectively; p = 0.049, ES = 1.08), while sensory/autonomic scales showed trends. No treatment-related adverse events occurred in the AT-04 group. Conclusions: AT-04 did not significantly reduce pain NRS but improved motor function in CIPN patients, especially in those >1 year after chemotherapy. AT-04 may be a promising non-pharmacological option; larger confirmatory trials are required. Full article

Overhead transmission lines are crucial components of power grid construction, and their carbon emissions significantly impact the low-carbon construction of the power grid. This study adopts a cradle-to-gate life cycle assessment (LCA) method, defining the system boundary as the material production, transportation, and construction phases. Using the carbon-accounting software eFootprint and the emission factor method, we calculate and analyze the carbon emissions of a 500 kV double-circuit overhead transmission line project in Shantou, Guangdong Province, and systematically examine the emission characteristics from material production through construction. Results show that the material production phase dominates the carbon emissions of the project, accounting for 99.82% of the total emissions. Among them, conductors (49.41%) and tower materials (37.28%) are the core sources of carbon emissions, with a combined contribution of 86.69%. The findings highlight conductors and towers as key targets for emission reduction through strategies such as optimized material selection, adoption of high-strength lightweight alternatives, and modular construction techniques. However, this analysis has limitations: it is confined to a single subtropical coastal project, relies on industry-average emission factors from the CLCD database (with inherent methodological uncertainties), excludes operational and end-of-life phases, and should not be generalized without regional validation. While the study identifies key emission hotspots and potential mitigation levers, quantitative low-carbon design guidance requires project-specific data and full life-cycle assessment. Full article

The actual implementation of fifth-generation (5G) and beyond networks faces persistent challenges, including environmental interference and limited coverage, which compromise transmission stability and network feasibility. Reconfigurable Intelligent Surfaces (RISs) have emerged as a promising technology to dynamically reconfigure wireless propagation environments and enhance communication quality. To fully unlock the potential of RIS, this paper proposes a novel deployment strategy based on Double Deep Q-Networks (DDQNs) that jointly optimizes the RIS placement and phase shift configuration to maximize the system sum-rate. Specifically, the coverage area is discretized into a grid, and at each candidate location, a DDQN-based method is developed to solve the corresponding non-convex phase optimization problem. Simulation results reveal that our proposed strategy significantly surpasses conventional benchmark schemes, resulting in a sum-rate improvement of up to 38.41%. The study provides a practical and efficient pre-deployment framework for RIS-enhanced wireless networks. Full article

This paper addresses the attitude tracking control problem for laterally symmetric vehicles during the boost phase under aerodynamic parameter variations and high-altitude wind disturbances. A neural disturbance observer-based nonsingular predefined-time sliding mode control scheme is proposed. First, a Lyapunov-based predefined-time stability criterion is established, which facilitates the design of an adaptive predefined-time observer using radial basis function neural networks. Without requiring prior knowledge of disturbance bounds, this observer ensures that disturbance estimation errors converge to a neighborhood of the origin within a predefined time parameter. Second, a novel nonsingular predefined-time sliding surface is constructed using hyperbolic tangent functions, leading to an integrated predefined-time sliding mode controller. The proposed scheme guarantees that the upper bound of the convergence time for initial attitude tracking errors is independent of the initial boost-phase states and can be arbitrarily predefined. Unlike conventional predefined-time control methods, the proposed approach eliminates controller singularity issues while avoiding the introduction of piecewise continuous functions or double-integral terms in either the sliding surface or the control law, thereby reducing structural complexity. Theoretical analysis confirms the boundedness of all closed-loop signals during attitude tracking. Numerical simulations demonstrate the effectiveness of the proposed control strategy under complex flight conditions. Full article

Reconfigurable intelligent surfaces (RISs) are an emerging wireless communication technology that has attracted significant attention, particularly in the field of physical layer security (PLS). This paper proposes a novel double-RIS-aided PLS communication system in a scenario where the direct links between the access point (AP) and the legitimate user/eavesdropper are blocked, based on an alternating optimization algorithm based on the manifold optimization (MOAO) algorithm, which jointly optimizes the transmit beamforming and phase-shift matrices of the RISs to enhance the system’s secrecy rate performance. The maximum ratio transmission method is adopted to optimize the beamforming vector, and the manifold optimization-based algorithm is utilized to simultaneously optimize the phase-shift matrices of the two RISs. Meanwhile, we also propose a successive convex approximation (SCA)-based algorithm as a benchmark scheme for comparison with the MOAO algorithm. Simulation results show that the MOAO algorithm achieves a significantly improved secrecy rate while exhibiting a reduced computational complexity on the order of $O(N_1^2+N_2^2)$ compared with the SCA-based benchmark. Full article

Background: Healthcare workers (HCWs) have experienced sustained occupational exposure to SARS-CoV-2 throughout the COVID-19 pandemic. While infection prevention and control (IPC) practices have been widely implemented, limited prospective data exist on how occupational exposure risk and adherence to protective practices evolve over time, particularly beyond the acute phases of the pandemic. This study aimed to prospectively assess occupational and community exposure risk to COVID-19 among HCWs and to evaluate temporal changes in adherence to IPC practices during routine care and aerosol-generating procedures. Methods: A prospective observational study was conducted among HCWs from four public hospitals in the region of Thessaly, Greece. Eligible participants were HCWs who reported contact with suspected or confirmed COVID-19 cases. The data were collected at baseline (January–March 2022) and at a six-month follow-up using the World Health Organization’s “Risk Assessment and Management of Exposure of Health Care Workers in the Context of COVID-19” questionnaire. The instrument captured demographic characteristics, professional roles, occupational and community exposure, and adherence to IPC practices. Results: A total of 203 HCWs participated in the study. The overall proportion of HCWs reporting occupational exposure was 72.9% in both assessments. Among HCWs with occupational exposure (n = 148), the proportion classified as high-risk showed a statistically significant increase from 76% (95% CI: 0.6951–0.8320) at baseline to 88% (95% CI: 0.8258–0.9310) at follow-up (p = 0.010). This shift reflects a substantial effect size, with the odds of high-risk classification being more than double at follow-up (OR = 2.24). Nurses consistently demonstrated higher risk compared with physicians. The overall use of personal protective equipment remained high. However, adherence to several IPC practices declined over time, including removal and replacement of PPE according to protocol and frequent decontamination of high-touch surfaces. Conclusions: Occupational exposure risk among HCWs remained substantial and increased over time despite stable occupational exposure estimates. The observed decline in adherence to key IPC measures highlights the need for continuous monitoring and reinforcement of protective practices in healthcare settings. Full article

In this paper, a wireless network architecture is considered that combines double intelligent reflecting surfaces (IRSs), energy harvesting (EH), and non-orthogonal multiple access (NOMA) with cooperative relaying (C-NOMA) to leverage the performance of non-line-of-sight (NLoS) communication mainly and incorporate energy efficiency in next-generation networks. To optimize the phase shifts of both IRSs, we employ a machine learning model that offers a low-complexity alternative to traditional optimization methods. This lightweight learning-based approach is introduced to predict effective IRS phase shift configurations without relying on solver-generated labels or repeated iterations. The model learns from channel behavior and system observations, which allows it to react rapidly under dynamic channel conditions. Numerical analysis demonstrates the validity of the proposed architecture in providing considerable improvements in spectral efficiency and service reliability through the integration of energy harvesting and relay-based communication compared with conventional systems, thereby facilitating green communication systems. Full article

The traditional mantis search algorithm (MSA) suffers from limitations such as slow convergence and a high likelihood of converging to local optima in complex optimization scenarios. This paper proposes an improved mantis search algorithm (IMSA) to overcome these issues. An adaptive probability conversion factor is designed, which adaptively controls the proportion of individuals entering the search phase and the attack phase so that the algorithm can smoothly transition from large-scale global exploration to local fine search. In the search phase, a probability update strategy based on both subspace and full space is designed, significantly improving the adaptability of the algorithm to complex problems by dynamically adjusting the search range. The elite population screening mechanism, based on Euclidean distance and fitness double criteria, is introduced to provide dual guidance for the evolution direction of the algorithm. In the attack stage, the base vector adaptive probability selection mechanism is designed, and the algorithm’s pertinence in different optimization stages is enhanced by dynamically adjusting the base vector selection strategy. Finally, in the stage of sexual cannibalism, the directed random disturbance update method of inferior individuals is adopted, and the population is directly introduced through the non-greedy replacement strategy, which effectively overcomes the loss of population diversity. The experimental results of 29 test functions on the CEC2017 test set demonstrate that the IMSA exhibits significant advantages in convergence speed, calculation accuracy, and stability compared to the original MSA and the five best meta-heuristic algorithms. Full article

The article considers issues related to improving the surface characteristics of titanium Gr2 using one of the lightest, cheapest and most ecological methods—electrospark deposition with low pulse energy and with ultradisperse electrodes TiB₂-TiAl with nanosized additives of NbC and ZrO₂. Using profilometric, metallographic, XRD, SEM and EDS methods, the change in the geometric characteristics, composition, structure, micro and nanohardness of the coatings as a function of the electrical parameters of the ESD regime has been studied. The results show that the use of TiB₂-TiAl electrodes and low pulse energy allows the formation of dense, continuous and uniform coatings that demonstrate a significant reduction in roughness, inherent irregularities and structural defects of electrospark coatings. Coatings with minimal defects, with crystalline–amorphous structures, with newly formed intermetallic and wear-resistant double and triple phases of the type AlTi₃, TiAl₃, TiB, TiN_0.3, Al₂O₃, AlB₂, TiC_0.3N_0.7, Ti_3.2B_1.6N_2.4, Al_2.86O_3.45N_0.55 have been obtained. Possibilities have been found for controlling and obtaining specific values for the roughness and thickness of coatings in the ranges Ra = 1.5–3.2 µm and δ = 8–19.5 µm, respectively. The electrical parameters of the modes ensure the production of coatings with previously known thickness and roughness, with increased microhardness up to 13 GPa, with the maximum possible content of deliberately synthesized high-hard phases and with ultra-fine-grained structures have been defined. Full article

Background/Objectives: Whether saponins aid in whey protein supplementation remains unclear. We aimed to investigate the effects of Astragalus and Panax saponins (APS) on whey protein absorption, intestinal permeability, and muscle function in healthy adults across different age groups. Methods: A randomized, double-blind, placebo-controlled crossover trial was conducted with 30 healthy participants equally stratified into three age groups (18–25, 26–59, and 60–80 years), over two phases: a single-dose trial to measure immediate amino acid absorption from whey protein and a 4-week phase combining daily supplementation with resistance training to assess long-term effects on amino acid absorption kinetics, muscle function, and gut health. Results: Immediate APS supplementation resulted in a 6.67% higher area under the curve for valine, 3.62% for leucine, and 0.15% for isoleucine, compared with the placebo. After 4 weeks, APS supplementation significantly increased the absorption of valine (14.07%) and leucine (8.34%) and improved the absorption of isoleucine (6.33%). The effects were most pronounced in older adults (60–80 years), who showed a 12.74% increase in total essential amino acid absorption. APS also caused a substantially greater increase (APS: +5.20% vs. placebo: +2.44%) in grip strength, an increase (APS: +0.85% vs. placebo: +0.68%) in muscle mass, and a reduction in blood zonulin levels (APS: −13.01% vs. placebo: −0.9%), indicating improved muscle function and intestinal barrier integrity, without adverse effects on liver or kidney function. Conclusions: APS supplementation enhances amino acid absorption from whey proteins, muscle function and gut barrier integrity, especially in older adults. These findings highlight its synergistic role in improving protein supplementation efficacy for those with age-related muscle loss. Full article

Background/Objectives: Tissue conductivity reflects ionic composition (e.g., sodium), providing critical insights into various diseases. Ultrashort echo time quantitative conductivity mapping (UTE-QCM) offers a method to obtain this information, which is particularly effective for musculoskeletal (MSK) tissues with short T2 relaxation times. The aim of this study is to develop a UTE-QCM framework using ultrashort echo time double echo steady-state (UTE-DESS) and validate its feasibility in the knee. Methods: An ultrashort echo time double echo steady-state (UTE-DESS) sequence was used to acquire S+ and S− images and estimate the transmit radiofrequency field (B1⁺) phase at 3T. The B1⁺ phase was derived by canceling the phase evolution in the free induction decay using these images. This phase data was then processed using two widely used QCM reconstruction methods for comparison: parabolic fitting and an integral-based method. The proposed UTE-QCM framework was validated using a phantom containing three different concentrations of sodium chloride (0%, 0.5%, and 1%). Additionally, three healthy volunteers were recruited to validate UTE-QCM in knee imaging. Results: In both phantom and in vivo experiments, the integral-based QCM demonstrated improved robustness to noise compared to parabolic fitting. In the sodium phantom, the estimated conductivity showed high linearity with sodium concentrations. In the in vivo knee, the generated conductivity maps successfully visualized both long and short T2 tissues. Conclusions: We demonstrated the feasibility of UTE-QCM as a novel quantitative imaging tool targeting short T2 tissues in the MSK system. This technique may facilitate the diagnosis and prognosis of joint disorders. Full article

Background: ExPEC9V is a 9-valent vaccine candidate designed to prevent invasive Escherichia coli disease, a life-threatening condition occurring when extraintestinal pathogenic E. coli (ExPEC) invade sterile sites. We evaluated immunogenicity and safety when ExPEC9V was co-administered with high-dose (HD) quadrivalent seasonal influenza vaccine. Methods: This Phase 3, double-blind, placebo-controlled study (NCT06134804) randomized 959 adults (≥65 years) to receive co-administration of ExPEC9V and HD quadrivalent seasonal influenza vaccine (CoAd) or each vaccine alone, 29 days apart (Control). Co-primary objectives were non-inferiority of co-administration versus separate administration following predefined criteria based on influenza strain-specific hemagglutination inhibition (HAI) antibody titers and ExPEC9V O-serotype binding antibody levels (multiplex electrochemiluminescence-based immunoassay), 29 days post vaccination. Reactogenicity and safety were assessed. Results: Co-administration of ExPEC9V with HD influenza vaccine demonstrated non-inferiority (upper bound of 2-sided 95% confidence interval [CI] < 1.5 for HAI geometric mean ratio [Control/CoAd]) for all influenza strains. Non-inferiority for ExPEC9V O-serotype antibody levels was not demonstrated (upper bound 95% CI > 1.5). One of nine serotypes met the non-inferiority criterion; eight did not, with four narrowly failing to meet the non-inferiority criterion. ExPEC9V immunogenicity was similar regardless of urinary tract infection history. ExPEC9V was safe and well tolerated, with no serious adverse events related to ExPEC9V. Reactogenicity rate was higher with co-administration. Conclusions: Co-administration of ExPEC9V with HD influenza vaccine met non-inferiority criteria of humoral immune responses for influenza antigens, but not for ExPEC9V O-serotype antigens. ExPEC9V, administered alone or with HD influenza vaccine, was safe and well tolerated, with an acceptable reactogenicity profile. Full article

Light-emitting diodes (LEDs) are becoming increasingly important across various sectors of the lighting industry and are being used more frequently. In the field of symbolic projection, research is increasingly focusing on implementing light modulation using energy-efficient, incoherent LEDs rather than lasers. Since light modulation in micro- and nano-optics is typically achieved through phase modulation, Finite-Difference Time-Domain (FDTD) simulations are employed for analysis. The objective of this article is to investigate different approaches for approximating incoherent monochromatic light sources within FDTD simulations. To this end, two approaches based on dipole sources are considered, as well as a method involving plane waves with modulated wavefronts based on Cosine–Fourier functions and a method based on the superposition of Gaussian beams. These methods are evaluated in terms of their accuracy using a two-dimensional double-slit configuration and are compared against a fully incoherent analytical reference. Full article

Distributed drive electric vehicles (DDEVs) offer remarkable advantages in handling stability owing to the independent torque and steering control of each wheel. Traditional in-dependent strategies have the disadvantages of slow response speed and unsmooth control interval switching. To overcome the performance tradeoffs of traditional independent strategies, this study proposes an integrated control approach combining four-wheel steering (4WS) and direct yaw moment control (DYC) to achieve coordinated multiobjective optimization. Based on phase-plane theory, the vehicle’s stable domain is divided using a double line method, and speed-dependent control regions and weights are designed to enable smooth switching between control modes. Simulation results demonstrate that, in high-adhesion conditions, compared with the DYC-only strategy, the integrated system reduces the maximum sideslip angle by about 77.8% and the cost function peak by 22.4%. Moreover, it decreases the maximum rear-wheel steering angle by 38.4% and maximum sideslip angle by about 15.4% compared with 4WS-only strategy. Under low-adhesion conditions, compared with the DYC-only strategy, the integrated system reduces the maximum sideslip angle by about 21.1% and the cost function peak by 37.6%. Additionally, the integrated system decreases the maximum rear-wheel steering angle by 60.2% and maximum sideslip angle by about 64.3% compared with 4WS-only strategy. Full article