Search Results (1,415)

Accurate calculation of mutual inductance (MI) between solenoid coils is essential for system design, but complex geometries and spatial arrangements make it challenging. This paper presents a modified analytical method for calculating the MI between two circular-wound air-core solenoid coils arbitrarily oriented in three-dimensional (3D) space. The analytical model used to calculate the MI between two solenoid coils is based on the use of magnetic vector potential (MVP). The helical structure of the solenoid coils is represented by successive coaxial circular filaments arranged along their central axes. Each filament is represented by an equivalent regular polygon with a sufficient number of sides. The proposed approach allows the MI between two solenoid coils to be calculated using a single analytical formula, without imposing restrictions on the relative positions of the coils, while taking lateral and angular misalignments into account. The modified analytical model is validated for accuracy and applicability by comparing its results with experimental measurements and FEM-based simulation results for coil systems with different diameters, turn numbers, and turn pitches. The MI results for various angular and lateral misalignments are in good agreement with experimental measurements and FEM results. The MI calculation model proposed in this work provides a fast and reliable tool for analyzing the electromagnetic behavior of coupled coil systems, designing inductive power transfer systems, and assessing electromagnetic compatibility. Full article

To evaluate the potential of defatted and dephenolized walnut meal as a modified functional food ingredient, this study examined how ball milling and processing time affect its structural, physicochemical, and functional properties. Walnut meal was ball-milled for 5, 10, 15, and 20 h. Ball milling increased the lightness and whiteness, reduced particle size, and broadened the particle size distribution into a characteristic three-peak pattern. Scanning electron microscopy revealed the progressive formation of flake-like surface structures. With increasing milling duration, free sulfhydryl groups, surface hydrophobicity, and solubility were increased, while dynamic surface tension decreased, leading to improved foaming capacity and foaming stability. SDS-PAGE confirmed that the primary structure remained unchanged, while Fourier transform infrared spectroscopy indicated a decrease in α-helix and β-sheet contents and an increase in random coil structures. X-ray diffraction revealed a reduction in the diffraction peak at 2θ = 8.963°, and differential scanning calorimetry showed irregular changes in the thermal stability with ball milling time. Overall, increasing ball milling time is beneficial for improving the functional properties of walnut meal, providing a preliminary theoretical reference for the potential application of walnut powder in foods with specific functional properties, such as aerated foods. Full article

Wireless power transfer (WPT) systems for electric vehicles (EVs) are increasingly being studied in the MHz range to increase power density and reduce the size of passive components. However, operation at higher frequencies significantly changes electromagnetic interference (EMI) behaavior. Fast switching in SiC- and GaN-based inverters, high-Q resonant operation, and frequency-dependent parasitic capacitances create conductive, capacitive, and magnetic interference mechanisms that are less significant in conventional kHz-range systems. Although many existing studies focus on power-transfer efficiency and converter optimization, EMI mechanisms in MHz-range EV WPT systems remain insufficiently systematized from a system-level electromagnetic perspective. This paper presents a state-of-the-art review of EMI generation mechanisms and system-level effects in high-frequency WPT systems for electric vehicles. The review considers the main interference sources and coupling paths, including switching-induced common-mode currents, resonant amplification of current and voltage stress, capacitive coupling between the coupler and nearby conductive structures, and magnetic-field redistribution caused by coil misalignment. Special attention is given to the transition from lumped-element assumptions to more distributed electromagnetic behavior at higher frequencies. The review also discusses the possible impact of these mechanisms on vehicle electronic subsystems and highlights the need for frequency-aware electromagnetic design, integrated modeling, and more rigorous EMC assessment for reliable MHz-range wireless EV charging systems. Full article

Peanut protein (PP) is an abundant plant protein resource with limited gelation performance. In this study, the effects of co-precipitation with egg white protein (EWP) on the structural and gelation properties of PP were investigated. Structural analysis revealed that co-precipitation induced secondary structure rearrangement of PP, accompanied by decreased α-helix and β-sheet contents and increased random coil and β-turn contents. These changes were associated with the exposure of hydrophilic groups and the partial shielding of hydrophobic regions, contributing to the significantly improved solubility of PP-EWP co-precipitated proteins (p < 0.05). These structural changes were conducive to the formation of a denser and more continuous gel network. Compared with the PP gel, the gel prepared from PP-EWP co-precipitated protein at the PP:EWP ratio of 2:1 showed an increase in gel strength from 429.30 g to 911.94 g and in water holding capacity from 56.78% to 85.53%. This study provides a theoretical basis and practical guidance for improving the gel properties of PP through co-precipitation and developing functional peanut protein ingredients, although the relatively high cost of EWP should be considered in practical applications. Full article

This study added two types of resistant dextrin (RD), i.e., Bailong (BL) and Luo Gaite (LGT)) to a Japonica (cv. RXY) and an early indica (cv. IP44) rice during cooking and analysed the functional and structural properties of the cooked rice. Compared with no RD addition, 3–10% RD addition induced a declinein cooking time and an incrementin gruel solid loss. Further, 3–10% RD addition increased the hardness, chewiness, and springiness of cooked rice but decreased the cohesiveness. With increases in the added RD amount, the smell, structural appearance, palatability, taste, cool rice texture, and total score of the cooked rice all increased; the peak time and pasting temperature increased, but the peak, final, breakdown, and setback viscosities all significantly decreased. The enthalpy, conclusion temperature of gelatinisation, and gelatinisation peak width and height all decreased with increasing RD amount, but the peak temperature of gelatinisation increased. The addition of 3–7% RD did not change amylopectin ageing, but 10% RD significantly increased amylopectin ageing. RD addition reduced the protein weakness degree and starch breakdown torque of rice doughbut appeared to increase the amorphous and crystalline regions of cooked rice. The addition of 10% BL or LGT induced the formation of α-helix and random coil secondary protein structures in cooked rice, with optimal cooking properties and total sensory score. Microstructure analysis further showed that low-viscous RD induced the formation of new gel-like structures. In conclusion, 3–10% RD addition in cooking rice decreases amylose recrystallisation, weakens the protein structure, and induces new gel-like structures, enhancing the hardness, chewiness, adhesiveness, springiness, and sensory score of cooked rice. This study is useful for developing functionalcooked rice. Full article

Heparin is a highly sulphated polyelectrolyte, and its properties depend strongly on its shape in solution. In this study, we closely examined the structural behaviour of low-molecular-weight heparin under aerobic ultraviolet-C (UVC, 100–280 nm) radiation. Using controlled photodegradation, we prepared native, small, and ultra-small molar-mass fractions, enabling us to investigate how structural properties vary with molecular weight. We examined relationships among molar mass, radius of gyration, second virial coefficient, and critical overlap concentration to characterise different conformational states. Our results showed that as molar mass decreased, the chain diameter and persistence length also dropped, while the overlap concentration increased. This indicates a reduced hydrodynamic volume and increased chain flexibility. Positive second virial coefficient values indicate that polymer–solvent interactions remained favourable after photodegradation. The scaling exponents suggest that degraded heparin behaves as a semi-flexible polyelectrolyte and adopts an extended-coil shape in water with electrolytes. Further analysis showed that the characteristic ratio and chain stiffness decreased as chains were broken by irradiation. Overall, aerobic UVC irradiation provides a reliable way to modify the physical structure of these molecules while maintaining solution stability. These findings show a clear link between reduced molecular weight and changes in shape, which is useful for developing better low-molecular-weight heparins for several applications, including pharmaceutical and medical use. Full article

This study proposes a printed circuit board (PCB) stator pattern for alleviating the trade-off between DC copper loss and AC winding loss in a slotless axial flux permanent magnet motor (AFPM). The proposed pattern has a structure in which the width of the effective conductor region directly exposed to time-varying magnetic flux is reduced, and two additional conductors with the same width are placed within the available axial space and then connected in parallel through vias. Three-dimensional finite element analysis was performed while varying the effective conductor width ratio from 0.3 to 0.8, and an additional refined sweep was conducted in the range of $\alpha$ = 0.5–0.6, where the minimum total winding loss appeared in the initial sweep. Under the rated operating condition, the minimum total winding loss was obtained at $\alpha =0.53$ based on the refined sweep results. Under this condition, the phase resistance, DC copper loss, AC winding loss, and total winding loss were reduced by 11.82%, 12.1%, 15.09%, and 12.48%, respectively. As a result, the efficiency increased from 81.53% to 83.5%, while the back electromotive force (BEMF), torque, and output were nearly unchanged. In addition, the AC winding loss distribution decreased in both the coil region closest to the magnets and the coil region farthest from the magnets. These results demonstrate that the proposed pattern is an effective design method for improving the winding loss characteristics of slotless PCB AFPM without meaningful degradation of the fundamental electromagnetic performance. Full article

Porcine blood meal-derived hydrolysate peptides and hemin are natural antioxidants, and the formation of peptide–hemin conjugates can synergistically improve antioxidant performance. Ultrasonic (US) treatment facilitates the binding of different molecules. Therefore, in this study, the effects of ultrasonic power treatments on the antioxidant activity and binding behavior of peptide–hemin conjugates were investigated. The spatial structure of the peptide–hemin conjugates was characterized using endogenous fluorescence spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, and circular dichroism (CD) spectroscopy, respectively. The results demonstrated that the peptide–hemin binding rate reached the highest value of 91.63% at 400 W US power, with structural changes in conjugates from α-helix to random coil structures. Additionally, US treatment increased the surface hydrophobicity and reduced the enthalpy change in conjugates. The antioxidant capacity was greatly improved and peaked at 400 W US, where DPPH and ABTS radical scavenging rates exceeded 55% and 65%, respectively. This study provided a scientific basis for the high-value utilization of US treatment on porcine blood meal resources. Full article

To address the insufficient damping and instability tendency of metal coil spring isolators subjected to intense impact loading, a multi-stage vibration isolation configuration integrating polyurethane, springs, and eddy current dampers is proposed. Dynamic models for both single-stage and multi-stage isolation systems are formulated, and a corresponding simulation model is developed in MATLAB R2023b/Simulink to investigate the peak suppression and attenuation characteristics of the multi-stage isolation under impact. To characterize the nonlinear finite deformation and time-dependent response of polyurethane, a hyperelastic-viscoelastic constitutive model is established by coupling the Ogden hyperelastic model with a generalized Maxwell viscoelastic model, with model parameters identified through quasi-static compression and stress relaxation tests. Drop impact experiments are performed to compare the displacement response, top- and bottom-plate peak accelerations, and vibration isolation rate between a polyurethane-spring-eddy-current multi-stage isolator and a spring-spring-eddy-current multi-stage isolator. The results demonstrate that the multi-stage structure enables staged dissipation of the impact energy, substantially reducing both the peak acceleration and the displacement stroke of the isolated mass. Under all drop test conditions, the polyurethane-based multi-stage isolator yields lower top-plate output peak acceleration and higher isolation rate than its all-spring counterpart, confirming its superior isolation performance. Envelope fitting of the simulation-based output acceleration with experimental inputs reveals that the all-spring multi-stage isolator exhibits a higher attenuation rate and equivalent damping ratio, whereas the polyurethane-based isolator achieves more effective suppression of the output peak level under severe impact conditions. Full article

Background/Objectives: This study evaluated the reproducibility of brain morphometric measurements obtained with different head coils and acceleration factors on a PET/MR scanner, with the aim of supporting reliability in longitudinal neuroimaging studies following major scanner hardware upgrades and introduction of higher-channel-density coils for improved image quality and shorter acquisition times. Methods: Fifteen healthy subjects underwent MPRAGE imaging on a 3T PET/MR scanner using a 16 channel head/neck coil with acceleration factor 2 and a 32 channel PET-transparent head coil with acceleration factors 2 and 4. Cortical thickness and subcortical volumes were measured with FreeSurfer. We performed correlation analyses to test the association between the values of cortical thickness and subcortical volumes derived from MPRAGE images acquired with either the 16- or the 32 channel coil. Test–retest variability and intraclass correlation coefficient were calculated to assess the reproducibility of the measurements for each brain region generated by each sequence and coil. Results: Cortical thickness and subcortical volume measurements from images acquired with different coils and acceleration factors showed high correlation (R = 0.96–1.00, p < 0.001) between protocols, with median test–retest variability below 4% for cortical thickness and a structure-dependent pattern for subcortical volumes, with higher variability in smaller structures such as the accumbens, reaching approximately 7.9% in cross-coil comparisons. Conclusions: Overall, brain morphometry measurements were reproducible across acquisition conditions. Coils with a higher number of channels were associated with improved signal-to-noise ratio, shorter acquisition times, and maintained quantitative consistency. Full article

This study introduces and characterizes a family of quilling-inspired S-shaped unit-cell architectures intended as building blocks for mechanical metamaterials. In contrast to conventional lattice designs based mainly on straight struts, the proposed geometries use continuous curved elements inspired by paper quilling, enabling deformation mechanisms dominated by bending, rotation, and progressive opening of the curved members. By translating quilling’s coiled and spiraled patterns into engineered geometries, nine distinct S-shaped unit cells were fabricated by fused deposition modeling and tested experimentally under uniaxial tensile loading. Finite element analysis was performed to reproduce the tensile response and to assess the influence of geometry on stiffness, stretchability, and energy absorption. The results show that relatively small changes in radii, span lengths, angular distribution, and symmetry produce significant differences in mechanical response. Compact configurations such as S2, S3, and S5 exhibit high stiffness and limited elongation, whereas S9 shows the highest compliance and stretchability. The results indicate that these quilling-inspired architectures provide a tunable design space and have strong potential for applications in energy absorption, adaptive structures, and lightweight load-bearing systems. Full article

Hemp seed protein hydrolysate (HSPH), despite its high digestibility and solubility, exhibits severely impaired gelation properties due to extensive hydrolysis, thereby limiting its food applications. This study analyzed the effect of homogeneously incorporating commercial hemp seed protein concentrate (HSPC) into HSPH on physicochemical and structural properties of the resultant composite gels. As the HSPC concentration increased from 100 to 150 mg/mL, the composite gels exhibited a significant enhancement in hardness (p < 0.05), increasing from 1.63 to 5.74 N, along with an improvement in water-holding capacity (WHC) from 45.52 to 55.46 g/g. Concurrently, the storage modulus (G′) and gelation temperature increased, with the latter rising from 65 to 78 °C. SDS-PAGE analysis suggested that the enhanced composite gel properties were attributed to its high-molecular-weight protein fractions (10–15 kDa and 40–50 kDa) of HSPC, which functioned as the primary structural components of the gel network. In addition, the formation of denser yet irregular microstructures was observed by scanning electron microscopy (SEM) analysis when HSPC incorporation increased from 0 to 200 mg/mL. Fourier-transform infrared (FTIR) further suggested that these improvements were due to increases in β-turn and random coil contents by approximately 9.60 and 7.73%, respectively. These findings provided insights into the utilization of HSPH and HSPC in plant-based foods and contributed to food security and sustainable agriculture. Full article

Thin-slice high-resolution computed tomography (CT) has improved the detection of small pulmonary nodules, increasing the demand for minimally invasive diagnostic and therapeutic resection. While lobectomy with lymph node dissection remains the standard surgical approach for many patients with resectable non-small cell lung cancer, accumulating evidence supports sublobar resection for selected small, peripheral, and ground-glass-dominant lesions when sufficient margins are achievable. In thoracoscopic and robotic surgery, localization of nodules ≤10 mm or lesions located >5 mm from the pleural surface can be challenging, and failure to identify the target may lead to conversion, larger resection than intended, or prolonged operative time. Several localization strategies have been developed, including CT-guided percutaneous wire/coil/dye marking, bronchoscopic dye mapping, and virtual-assisted lung mapping (VAL-MAP), robotic-assisted bronchoscopic dye or fiducial localization, radiofrequency identification microtag systems (Surgical Real-Time FInger Navigation and Detection) that provide real-time depth information, and single-stage intraoperative CT-guided marking and resection in hybrid operating rooms. This review synthesizes representative evidence and published outcome ranges, and compares workflows, marker-to-lesion precision metrics, complication profiles, operational burden, and cost structures. We emphasize the practical contrast between two-stage and single-stage workflows, the access-route differences between transthoracic and transbronchial techniques, and the need to report localization-to-incision “time at risk”. We also present an expert-consensus decision algorithm aimed at facilitating tailored selection of localization strategies for modern minimally invasive thoracic surgery. Full article

Background: The translocation of diet-derived antigens from the maternal intestine to breast milk represents a primary gateway for neonatal immune priming, yet the structural basis for why certain proteins survive this transit while others do not remains poorly understood. This review introduces the “Survivor Peptide” hypothesis, proposing that specific food allergens possess intrinsic “stability architectures” that enable them to resist maternal digestion and navigate the gut–mammary axis to reach the infant in an immunologically active form. Methods: We analyzed the current literature regarding the detection and structural characteristics of food allergens in human milk. Integrating evidence from 26 major sources, we performed an in silico structural analysis of five representative “survivor” proteins: Gal d 1 (egg white), Bos d 5 (cow’s milk), Gal d 6 (egg yolk), Tri a 19 (wheat), and tropomyosin (Der p 10-mite/shellfish). High-resolution 3D models were retrieved from the Protein Data Bank and AlphaFold2, and then visualized in UCSF ChimeraX to map stability anchors, including disulfide bonds and hydrophobic clusters, against solvent-accessible IgE-binding epitopes. Results: We identified and categorized allergens into distinct Molecular Resilience Architectures: the “Covalent Cage” (Gal d 1), defined by dense disulfide stapling, the “Glycoprotein Shield” (Gal d 6), utilizing yolk-matrix structural anchors, the “Topological Shield” (Bos d 5), characterized by a stable β-barrel, and “Coiled-Coil Rigidity” (Der p 10). These frameworks protect large, immunogenic fragments that maintain the spatial arrangement required for IgE cross-linking. Conclusions: Allergen persistence in the gut–mammary axis is dictated by a protein’s intrinsic structural architecture. Identifying these stability fingerprints provides a unified theory for allergen persistence and offers a path for refining component-resolved diagnostics and neonatal oral tolerance strategies. Full article

Broadband sound absorption in the low-frequency range remains a significant challenge in acoustics. Traditional sound-absorbing structures are constrained by bulky volumes, while acoustic metamaterials often involve complicated structural designs. In this work, we propose an acoustic metasurface by coupling multiple coiled-up structures, in order to achieve broadband near-perfect absorption in the low-frequency range. Capitalizing on complex frequency plane analysis, each coiled-up unit is tuned to critical damping, enabling perfect sound absorption. Through an interleaved arrangement of four coiled-up units with distinct parameters, the proposed metasurface achieves near-perfect absorption $\alpha >0.9$ within 261~372 Hz. The total thickness of the structure is 50 mm, corresponding to 1/26 of the wavelength at the lowest absorption frequency. Theoretical and simulated results confirm that sound waves at respective resonant frequencies can be captured and dissipated by the corresponding coiled-up units. Impedance tube experiments validate the accuracy of the adopted methodology, and demonstrate the potential of this metasurface for practical acoustic applications. Full article