Radiation is essential in medical diagnostics but poses health risks, necessitating effective shielding to minimize exposure. This research evaluates cassava starch-based bioplastic-lead as an alternative radiation shielding material in femur radiography using Anteroposterior (AP) and Lateral projections with portrait and diagonal detector positions. Bioplastic samples with a 45:55 ratio of cassava starch and lead acetate were tested on a preserved human femur with and without shielding. Image processing using the Gaussian High Pass Filter (GHPF) method and analysis with Contrast to Noise Ratio (CNR) and Peak Signal to Noise Ratio (PSNR) were conducted to assess image quality. Results showed that lead bioplastics achieved 49.4% radiation absorption, with optimal anatomical visualization at cut-off frequencies of 5 and 10, while higher frequencies led to image distortions resembling osteoporosis. The best CNR and PSNR values confirmed improved image contrast while maintaining diagnostic accuracy. This research demonstrates that lead bioplastic effectively reduces radiation dose while preserving image quality, making it a promising alternative shielding material for medical imaging applications

MXene-based layered films featuring a "brick-and-mortar" architecture show significant potential for electromagnetic interference (EMI) shielding applications; however, the insulating polymer "mortar" disrupts the connectivity of the MXene network, ultimately compromising both electrical conductivity and shielding effectiveness (SE). To address this limitation, this study introduces an innovative interpenetrating layered structure, comprising independent aramid nanofiber (ANF) layers and MXene layers, fabricated through a directional freeze-thaw intercalation-gel-film formation strategy. Unlike traditional homogeneous layered films, this unique layered structure features mutually embedded conductive and insulating layers, facilitating efficient electron transport, generating numerous heterogeneous interfaces for multiple reflections and scattering, and enhancing oxidation resistance. The interpenetrating ANF/MXene film exhibits exceptional electrical conductivity (5630.8 S/m) and EMI SE (43.3dB) at ∼40 wt.% MXene loading, significantly outperforming the homogeneous ANF/MXene film (26.9dB). Importantly, the interpenetrating ANF layers fully encapsulate the MXene layers, providing remarkable long-term stability with only a 10% decline in EMI performance after 80 days of aging. Furthermore, the interpenetrating ANF layers form a resilient mechanical framework, resulting in the A@M film boasting outstanding mechanical properties (tensile strength of 121.0MPa, fracture strain of 13%). Consequently, this work presents a novel design and approach for fabricating high-performance MXene-based layered EMI shielding films.

To address the long-standing challenge of chemoselectivity in manufacturing flexible π-allyl Pd dipoles containing extended linkers, we report a new palladium/metal alkoxide-based double activation catalysis. This catalytic system enables the successful generation of TMM oxa-1,5-dipoles from homoallylic alcohol derivatives via a conceptually distinct "locking-releasing" mechanism, wherein the shielding effect of a bulky metal alkoxide moiety is likely a key factor in the sequential process. The consequent [5 + 5] cycloaddition with cyclic vinylogous anhydrides provides direct access to valuable ten-membered lactones with a broad range of substituents at the C9-position. Moreover, chemoselectively engendering π-allyl Pd 1,7-dipoles with a fully saturated linker in the related [7 + 5] cycloaddition further demonstrates the viability of the catalytic system, affording various sp3-rich 12-membered lactones.

Electromagnetic interference (EMI) remains a critical challenge for modern electronic systems, driving the need for lightweight materials with efficient shielding capabilities. In this work, Fe3O4@RGO hybrid nano-fillers were synthesized via a co-precipitation route and incorporated into a poly(di-allyl phthalate) (PDAP) matrix to produce composite films with tunable dielectric-magnetic coupling. Structural analyses confirmed the uniform decoration of Fe3O4 nanoparticles on RGO sheets and their homogeneous dispersion within the PDAP network. The calculated electromagnetic parameters (ε' ≈ 12, ε″ ≈ 4, µ' ≈ 1.3, µ″ ≈ 0.3 at 10GHz) reveal strong dielectric and magnetic loss channels that support an absorption-dominated shielding mechanism. The optimal composite (PMR20) achieved a total shielding effectiveness of ~ 31.5 dB across the X-band, corresponding to > 99.9% attenuation of incident radiation, with SEA contributing the major portion of the overall SE. The synergy between conductive RGO pathways, magnetic relaxation of Fe3O4, and interfacial polarization within PDAP underpins the enhanced attenuation behavior. This study demonstrates PDAP as a promising and underexplored thermosetting host for hybrid EMI shielding materials, offering a platform for lightweight and high-performance electromagnetic protection.

Abstract It becomes essential to improve electromagnetic interference (EMI) shielding for high-speed, sensitive RF electronic devices when packaged in a shielding metal enclosure. The shielding effect by transmission (SET) was evaluated for 13 metal plates, which were considered as shielding unwanted EM waves. Most of the $$\mathrm S_{21}$$ measurements for metals showed a similar high reflection performance at 6 GHz. However, when a 6-GHz low-noise-amplifier (LNA) was packaged in an aluminum die-casting (ADC) mold and covered with a high-SET metal lid, a sharp peak in $$\mathrm S_{21}$$ at 5.2 GHz was observed. It was confirmed that the internal output signal radiated from the output signal pin between the PCB and the ADC, caused by impedance mismatch, was reflected at the bottom of the lid, propagated, and changed the total phase by 5 $$\pi$$ , and was incident on the input stage of the LNA, causing resonant oscillation at 5.2 GHz. When the iron-based EM wave shielding (EMWS) sheet was attached to the metal lid bottom, the shielding effect by absorption (SEA) was increased by about 10 dB, and the sharp peak on the $$\mathrm S_{21}$$ curve disappeared. This phenomenon was also investigated during the EVM evaluation for 64-QAM-OFDM transmission. When the LNA package was covered with an ADC lid, the EVM increased by approximately 10 dB due to increased quadrature error (Quad-Err). When the LNA package was covered with an ADC/EMWS lid, the EVM and Quad-Err were substantially suppressed. It is essential to shield electronic devices from both external and internal EMI by using high-SEA and SET materials to achieve high-quality QAM-OFDM transmission.

The development of electronic devices for communication systems, radar warning, and satellite detection requires lightweight materials that exhibit exceptional electromagnetic interference (EMI) shielding while maintaining mechanical robustness. However, designing three-dimensional (3D) structured pristine graphene (PG) that achieves both high EMI shielding and substantial load-bearing capacity remains a significant challenge. In this work, an innovative method of 3D skeleton preconstruction-infiltration filling is proposed. This approach demonstrates that molten AZ91D is infiltrated into the 3D structured PG@pyrocarbon (PG@PyC), and its 3D structure can be maintained in the AZ91D matrix via a liquid-solid infiltration extrusion method. By utilizing this strategy, PG@PyC reinforced AZ91D matrix (PG@PyC/AZ91D) composites display remarkable comprehensive performance, realizing an EMI shielding effectiveness of 76.70 dB (at 3 mm thickness), ultimate compressive strength of 276 MPa, and ultimate tensile strength of 231 MPa. The developed composites are promising lightweight materials for the integration of structural and functional applications in complex environments.

Overhead transmission lines are critical carriers for power delivery, directly influencing the security of the power system. In high-altitude areas, special environmental conditions such as low air pressure and intense solar radiation significantly change the heat absorption and dissipation characteristics of conductors. Therefore, it is necessary to correct the overhead conductors’ ampacity in such areas to ensure safe operation. However, the ampacity calculation method and high-altitude ampacity correction coefficients proposed in existing standards have significant limitations, and there are also large errors in the calculation results. Therefore, based on the system of partial differential equations proposed in the “Guidelines for Calculating the Current-Carrying Capacity of Transmission Conductors at High Altitudes” and the suggestions for high-altitude meteorological parameter modifications from existing standards, this paper establishes a three-dimensional finite element model to study the ampacity calculation method for overhead conductors in high-altitude areas. The results show that a significant thermal shielding effect exists among bundled conductors, and meteorological condition variations significantly influence the temperature distribution of the conductors and their surrounding space. At altitudes of 4000~5000 m, the altitude correction coefficient for both twin-bundle and quad-bundle conductors is −0.06 A∙m−1 under specific conservative conditions.

Abstract This study investigates the incorporation of cerium oxide (CeO2) and lanthanum oxide (La2O3) into 45S5 bioactive glass to enhance its radiation shielding properties, critical for nuclear and biomedical applications. Traditional evaluation methods, including simulations and experimental testing, are often resource-intensive. To address this, a machine learning approach was employed to predict these properties in (CeO2+La2O3)-doped 45S5 bioactive glass. Several Machine learning models, including Random Forest, LightGBM, Support Vector Regressor, CatBoost, and XGBoost, were trained and validated using data from EpiXS and Monte Carlo Geant4 simulations, achieving high predictive accuracy. The machine learning model results, including predictions for mass attenuation coefficients (MAC), which serve as key indicators of radiation shielding effectiveness, were compared to Monte Carlo Geant4 simulations and the EpiXS database, demonstrating strong agreement. Among the evaluated models, CatBoost, Extra Trees, LightGBM, and Random Forest demonstrated solid predictive accuracy, with R2 scores of 0.9999, 0.9998, 0.9996, and 0.9996 , respectively. Although slight deviations were observed at very low photon energies (<0.1 MeV), reflecting the increased complexity of photon-matter interactions in this region. These results highlight the potential of machine learning to improve the optimization of doped bioactive glasses, significantly reducing the time and cost of conventional methods. This approach enables the rapid development of bioactive glass compositions with enhanced mechanical and radiation shielding properties, advancing biomedical implants and protective materials for radiological applications.

This paper presents a pre-industrial, laboratory-stage version of an innovative sensor box designed to enable remote measurement of electrical currents. The proposed prototype functions as a drone-mounted payload that can be deployed onto overhead transmission lines. Utilizing Hall-effect sensors, electronic signal processing through filtering, and digital data transmission via Arduino and Bluetooth, the instantaneous line currents are visualized in MATLAB (R2023a) as time-based curves. The sensor box can also be remotely released from the transmission line once measurements are complete, allowing a fully autonomous mode of operation. Laboratory tests demonstrated promising results for real-world applications, with measurement efficiencies ranging from 92% to 98% under various test conditions, including stress tests involving harmonics and total harmonic distortion up to 40%. Future work will focus on implementing effective shielding against high electric fields to further enhance reliability and advance the sensor’s industrialization as a novel solution for power grid digitalization.

Lipid nanoparticles (LNPs) are the most widely applied nanocarriers for mRNA delivery in clinical use. However, the limited stability and increasingly recognized immunogenicity of PEG-based LNP formulations are potential impediments to the more widespread development of mRNA therapeutics. To address shortcomings in current LNP polymer coatings, we have developed a polymer-lipid conjugate based on the low-fouling sulfoxide polymer poly(2-(methylsulfinyl)ethyl acrylate) (PMSEA). The results show that LNPs formed from the PMSEA-DSPE conjugates with optimized polymer chain length have excellent stability, highly effective shielding, and low immunogenicity, favorable properties for PMSEA-DSPE to be incorporated as a component of mRNA nanocarriers. mRNA-LNP formulations were prepared with PMSEA-DSPE as an alternative to the PEGylated formulations. The stability, in vitro behavior, and transfection efficiency of the mRNA nanocarriers were evaluated, with PMSEA providing superior transfection efficiency compared with the PEG equivalents. This work demonstrates the potential of PMSEA mRNA-LNPs for further development as therapeutic delivery vehicles.

Herein, we report that 1,4-unsymmetric modification of the fullerene core can tune the site selectivity and reactivity of C60. An unconventional hydrated 4,5-dihydropyridazine ring structure was formed due to the site-selective 1,2,4,5-tetrazine cycloaddition of 1,4-unsymmetrical C60 adducts. Indole substituents on C60 have been found to create a shielding effect on the nearby [6,6] double bond, influencing its reactivity toward 1,2,4,5-tetrazine cycloaddition. Furthermore, we found that by varying the 1,4-unsymmetrical bifunctionalization, bifunctional sheltering-activation tuning could be reversed, allowing site selectivity to be modulated across different hemispheres of the fullerene. 1,4-Unsymmetric C60 adducts have been demonstrated as a significant platform for the discovery and site-selective preparation of multiadducts that are rare and challenging to synthesize.

The ablation of solid materials using ultrashort laser pulses at high intensities leads to the emission of X-rays. This effect is particularly pronounced when burst pulses are applied due to pulse-to-pulse interactions within a burst. Simultaneously, the resulting surface topography changes depending on whether single pulses or burst pulses are used. This study experimentally investigates the spectral X-ray emission during the ablation of 304L-steel with single and burst pulses, varying the detection angle and predefined laser parameters. The aim is to analyze how surface topography, which evolves during ablation, influences the measurements of X-ray emission during area irradiation. The results indicate that surface topography-induced shielding of X-ray emission occurs for single and MHz-burst pulses, but only at fluences where characteristic surface structures form. In the MHz-burst regime, additional shielding effects arise from interactions with the ablation plume, which also contribute to a shift toward higher-energy X-ray photons. In contrast, GHz-burst pulses preserve a smooth surface across all investigated fluences, preventing shielding of X-rays.

Scalable solvent-free ambient-pressure drying (APD) of robust multifunctional MXene aerogels remains significantly challenging. We present a hydrophobic interaction-directed assembly strategy among MXene, chitosan (CS), and glutaraldehyde (GA) to engineer aerogels with programmable hydrophobicity-mechanics. Selective reduction of CS amine groups suppresses capillary forces upon solvent-free APD, yielding 4,477% compressive strength enhancement over conventional MXene aerogels. Composition tuning delivers switchable electromagnetic functionality: 25.6 wt.% CS generates a 76dB microwave shielding effectiveness, while 67.4 wt.% yields a 6.4GHz broadband microwave absorption, which is comparable to the best MXene aerogels. The APD MXene aerogels further exhibit exceptional thermal protection, characterized by a record-high limiting oxygen index of 60%, outstanding thermal insulation, reliable structural integrity at elevated temperatures, and a high-efficiency early fire-warning capability, outperforming previously reported nanostructured monoliths. This work offers a general, scalable, and solvent-free route for assembling MXene and other nonstructured aerogels with integrated mechanics and functionalities, advancing their application in aerospace and energy systems.

ABSTRACT The rapid advancement of electronic and communication technologies has led to a significant increase in electromagnetic (EM) pollution, necessitating the development of efficient electromagnetic interference (EMI) shielding materials to mitigate adverse effects on both human health and electronic systems. In this study, a series of ternary nanocomposites comprising NiFe 2 O 4 @carbon nanotubes (NFO@CNTs) was synthesized via the solvothermal method. Subsequently, NiFe 2 O 4 @CNTs were incorporated into polyvinylidene fluoride (PVDF) to fabricate PVDF/NiFe 2 O 4 @CNTs composites. The CNTs content was varied from 1 to 5 wt.% w.r.t NiFe 2 O 4 to optimize electrical conductivity and impedance matching, while tuning the synthesis temperature. X‐ray diffraction (XRD) and Raman analysis confirmed the successful formation of NiFe 2 O 4 @CNTs composites, while transmission electron microscopy (TEM) images revealed the uniform functionalization of CNTs, the anchoring of NiFe 2 O 4 nanoparticles on CNTs walls, and the formation of a 3D conductive network. Ternary composite NTC10(5) exhibited maximum EMI shielding effectiveness (SE T ) of 16.20 dB, equivalent to 97.61% attenuation, which further increased to 22 dB (> 99% attenuation) upon optimizing the processing temperature to 100°C. Additionally, electromagnetic wave (EMW) absorption performance was evaluated by introducing a metallic backing layer. The NTC7(1) sample demonstrated the highest reflection loss (RL min ) of −30 dB, corresponding to greater than 99.9% EMW absorption.

Abstract To address the significant degradation in shielding effectiveness of slotted cavity electromagnetic shielding during resonance band caused by cavity resonance frequencies, this paper proposes a method for enhancing the shielding performance of slotted cavity electromagnetic shielding by integrating frequency selective surface based on an electromagnetic topological structure model. First, calculate the electromagnetic shiel-ding effectiveness of the slotted cavity to determine the resonant frequency band of 0.7 to 0.72 GHz, modeling the slot as equivalent bandpass two-port network. Design a dual-layer frequency selective surface with miniaturization and band-rejection characteristic based on the resonant frequency band, and model it as an equivalent band-rejection two-port network. By cascading two models, a rapid analysis of the frequency selective surface enhanced slotted cavity shielding performance was achieved, thereby guiding the structural optimization design. Simulation results indicate that after applying the frequency selective surface, the electromagnetic shielding effectiveness within the 0.7 to 0.72 GHz resonance band increased from 10 dB to 62 dB. Physical testing confirmed that the electromagnetic shielding effectiveness across the entire 0 to 1 GHz frequency band exceeded 50 dB.

Three-dimensional porous foams and aerogels with high compressibility and elasticity hold great promise for applications in pressure sensing, electromagnetic interference (EMI) shielding, and thermal insulation. However, their widespread application is often hindered by compromised structural stability and inadequate fatigue resistance under repeated compression. Herein, a sustainable "top-down" cell wall reconfiguration strategy is proposed to fabricate highly elastic, fatigue-resistant, and electrically conductive lamellar wood sponge from natural balsa wood. This strategy involves the conversion of the intrinsic cellular structure of wood into an arch-shaped lamellar architecture reinforced by chemical cross-linking, followed by coating the lamellar scaffold with conductive polypyrrole (PPy) via in situ polymerization. The resulting PPy-coated cross-linked wood sponge (CWS@PPy) demonstrates reversible compressibility, excellent fatigue resistance (∼3.5% plastic deformation after 10,000 cycles at 40% strain). The strain-induced conductivity changes in CWS@PPy enable tunable EMI shielding effectiveness under cyclic compression and also facilities high-sensitivity pressure sensing (0.72kPa-1). Additionally, CWS@PPy exhibits a low through-plane thermal conductivity of 0.037 W m-1K-1, which can be dynamically tuned for adaptive thermal management. The proposed mechanically robust and conductive wood sponge provides a versatile and sustainable platform for next-generation smart devices.

All companies need to manage and optimize their debt policies to ensure effective financial and operational activities. This study aims to analyze and test the effect of non-debt tax shields, corporate tax rates, tangibility, and company growth on debt policy. The population in this study was 70 infrastructure sector companies listed on the Indonesia Stock Exchange. Fifteen companies were selected through a purposive sampling method. This quantitative research used the e-views 12 program and multiple regression analysis. The test results indicate that non-debt tax shields, corporate tax rates, tangibility, and company growth simultaneously influence debt policy. Partially, non-debt tax shields and corporate tax rates do not influence debt policy, while tangibility and company growth influence debt policy.

To break through the performance bottlenecks of electromagnetic protection materials in terms of lightweight design, broadband absorption, and multifunctional integration, this work proposes a synergistic design strategy based on magneto-dielectric coupled absorbing units and periodic micro-circular array superstructures. At the microscopic scale, oleic acid (OA)-modified γ-Fe2O3/graphene oxide (OA-γ-Fe2O3/GO) composite absorbing units were constructed and organized into precisely controllable millimeter-scale periodic micro-circular arrays. Acting as an artificial electromagnetic structure capable of actively modulating the electromagnetic field distribution, the array enables multiple scattering, progressive attenuation, and continuous impedance transition within the interface, thereby significantly optimizing the energy dissipation pathways. A pressing process was employed to integrate polytetrafluoroethylene (PTFE) onto the fabric surface, realizing a high-performance composite fabric with an overall thickness of only 0.128 mm. The resulting composite exhibits outstanding performance, with a shielding effectiveness (SET) of 73.99 dB, a minimum reflection loss (RLmin) of -31.56 dB, and an effective absorption bandwidth (RL < -10 dB) spanning 10.93-11.83 GHz. Meanwhile, it demonstrates excellent multifunctional properties, including a water contact angle of 125.7°, a tensile strength of 142 MPa, and the retention of 93% of its initial shielding performance after 10 000 bending cycles. Compared with commercial thin shielding textiles, the proposed material achieves an improvement of over 20% in shielding effectiveness and over 30% in absorption performance. This study not only provides a high-performance electromagnetic protection material but also establishes a cross-scale "unit-structure" synergistic design framework, offering a new fundamental paradigm for developing intelligent and adaptive electromagnetic protection systems. The strategy holds great potential for applications in stealth technology, aerospace engineering, and wearable electronics.

Modulating cationic-hydrophobic balance in hydrogel polymer nanoparticles for enhanced membrane interactions and antibacterial functions.

Effective dose estimation and gamma ray shielding properties of BaO added in gallium borate glass