Search Results (3,080)

For high-voltage power transmission, the surface voltage gradient (SVG) of the conductor plays a crucial role in meeting corona performance requirements. The SVG is greatly impacted by the smoothness of the conductor’s surface. Under identical conditions, the SVG of smooth, round conductors differs from that of stranded conductors with the same outer radius. This paper uses Finite Element Analysis (FEA) to study the effect of different stranded conductor geometries and three-phase line topologies with stranded conductor bundles on the SVG. Although industry standards and the scientific literature often rely on simplified smooth-cylinder approximations, this research demonstrates that surface irregularities significantly increase electrical stress compared to idealized smooth surfaces. Through simulating various three-phase configurations, the study reveals a nearly constant field enhancement factor across diverse stranded designs. These results enable us to apply formulas developed for smooth conductors to more realistic power line applications involving stranded conductor bundles. Consequently, this FEA approach offers engineers a precise, versatile method for designing high-voltage transmission lines. The findings presented here facilitate a deeper understanding of the SVG surrounding stranded conductors, particularly with regard to its influence on corona phenomena. Full article

With the gradual depletion of conventional hydrocarbon resources, low- and ultra-low-permeability reservoirs have become important targets for oil development. Nanoemulsions exhibit great potential for enhanced oil recovery because of their favorable interfacial activity, small droplet size, and excellent transport capability. However, the interfacial dynamics and capillary mechanisms involved in microscale two-phase displacement processes remain poorly understood. In this study, a self-developed micro-capillary bundle apparatus was used to investigate nanoemulsion displacement behavior in micrometer-scale capillaries. The interfacial behavior was quantitatively analyzed based on the relationship between interface velocity and pressure difference (v-ΔP). The results show that the displacement process follows the classical Washburn equation, with a linear relationship between v and ΔP. During oil displacement, the capillary force remains negative and acts as a resistance, indicating a pressure-driven forced displacement mechanism. Environmental factors such as temperature, electrolyte concentration, and wettability have limited effects, whereas pore size plays a dominant role. The addition of an appropriate amount of microspheres can reduce capillary resistance and lower the required driving pressure. The present findings mainly reveal the interfacial motion characteristics and capillary mechanisms of nanoemulsions in microscale pore throats, providing a fundamental basis for understanding fluid transport behavior in low-permeability reservoirs. Full article

Densely packed semiconducting carbon nanotube (CNT) arrays with well-controlled morphology are highly desirable for high-performance CNT-based electronics. Although dielectrophoresis (DEP) enables precise, efficient, and site-selective assembly, increasing array density often destabilizes process regulation and aggravates nanotube bundling because of the dynamic interplay among assembly conditions. Here, we introduce the effective deposition region (EDR) to reformulate DEP assembly into a framework that links DEP conditions and final arrays through an interpretable CNT deposition dynamic based on the effective DEP capture. Within this framework, experiments and modeling indicate a self-regulating, negative-feedback mechanism in which conductive CNT bridging reduces the gap voltage, contracts the EDR, and weakens sustained CNT-capture capability, thereby driving the assembly toward self-termination. By synergistically optimizing the applied voltage, electrode configuration, and CNT dispersion concentration to regulate EDR contraction, we obtained dense, bundle-suppressed CNT arrays with the number of nanotubes per unit width of approximately 140 tubes µm⁻¹. The formation of small bundles implies that further combination of EDR-regulated assembly with additional inter-tube interactions is required to realize dense, monolayer CNT arrays. This work provides a coherent mechanistic framework for understanding feedback-regulated DEP assembly and enables a practical approach for optimizing both densification and morphology control in CNT array assembly. Full article

Benign parotid tumors are increasingly treated with parenchyma-sparing extracapsular enucleation, yet postoperative salivary collections and Frey syndrome can still generate clinically relevant morbidity; we evaluated whether a standardized intraoperative bundle combining intraparotid botulinum toxin A (BTX-A) and bovine collagen membrane interposition is associated with fewer complications than standard enucleation alone. In this retrospective comparative cohort at a tertiary Head and Neck Surgery Unit, consecutive adults undergoing extracapsular enucleation for pleomorphic adenoma or Warthin tumor (2010–2025) were allocated by institutional era-based protocol to Group A (2010–2017, standard enucleation) or Group B (2018–2025, enucleation plus intraoperative intraparotid BTX-A 50 IU and bovine collagen membrane placement over the repaired parotid fascia). Prespecified endpoints were sialocele/salivary fistula, surgical-site infection (SSI) within 30 days, and clinically recorded Frey syndrome within 6 months; effect sizes with 95% confidence intervals were reported. A total of 188 patients were analyzed (94 per group). Sialocele occurred in 20/94 (21.3%) in Group A versus 2/94 (2.1%) in Group B [Relative Risk (RR) 0.10]. SSI occurred in 14/94 (14.9%) versus 2/94 (2.1%) (RR 0.143), and clinically recorded Frey syndrome in 18/94 (19.1%) versus 4/94 (4.3%) (RR 0.222). This combined protocol was associated with lower complication rates through 6 months; prospective controlled studies with standardized Frey assessment and longer follow-up are warranted. Full article

With the increasing occurrence of extreme high-temperature weather events, the traditional bundled operation of wind power (WP), photovoltaic power (PV), and pumped storage hydropower (PSH) is facing dual challenges, namely intensified renewable energy fluctuations and insufficient flexible regulation capability of PSH. Therefore, this paper proposes an optimal scheduling strategy for bundled operation based on capacity interval matching of PSH with WP and PV under extreme high-temperature weather. First, typical scenarios are generated based on a Time-series Generative Adversarial Network (TimeGAN), and an interval matching transaction model is established based on the forecast intervals of WP and PV capacity and the corrected intervals of PSH capacity. Second, considering PSH as an independent market entity, a bi-level optimization model is constructed, in which the upper-level objective is to maximize the revenue of PSH, while the lower-level objective is to minimize the total cost of the joint clearing of the energy and ancillary service markets. Finally, simulation case studies verify that under extreme high-temperature weather, the proposed optimal scheduling method increases the bundled operation capacity by 17.9% and improves the revenue of PSH in the reserve ancillary service market by 14.8%, thereby effectively enhancing the economic performance of PSH while ensuring the safe and stable operation of the system. Full article

Hyperdimensional computing (HDC) provides a highly efficient alternative to neural networks for intracranial electroencephalography (iEEG) seizure detection on edge devices with strict resource limits. While sparse HDC can significantly reduce energy use, current hardware fails to capitalize on this for two reasons. First, existing designs do not optimize the encoding architecture specifically for sparse execution, leaving potential energy savings on the table. Second, researchers often ignore the “area” problem, the large physical space high-dimensional vectors take up on a chip, which must be solved to make these devices small enough for practical edge use. This work presents a sparse HDC accelerator that bridges these gaps through three key contributions. First, we streamline the sparse encoding architecture to improve energy and area efficiency by integrating a compressed item memory (CompIM) and simplified spatial bundling. Second, to address the area bottleneck and enable true edge deployment, we systematically explore area trade-offs via sequentialization techniques, evaluating both channel folding (CF) and vector folding (VF). Third, we push efficiency even further by proposing an item-memory-free (IM-free) architecture. By replacing the baseline segmented shift binding with a standard shift binding scheme, and gracefully utilizing raw local binary pattern (LBP) codes directly as shift amounts, we completely bypass the CompIM for simultaneous area and energy savings. However, this optimization incurs a drop in detection accuracy; hence, we ultimately present two tailored configurations. First, our energy-optimized IM-free design achieves a 5.55× area and 3.08× energy improvement over the sparse HDC baseline, alongside 8.20× and 13.37× improvements over the dense baseline. Second, to prioritize clinical performance, our balanced streamlined design utilizes a channel folding factor (CFF) of 4 to preserve higher accuracy. This balanced approach achieves a 5.97× area and a 4.66× energy improvement over the dense baseline, with a 4× latency increase. Full article

Responding to rapid urbanization, this study examines the trade-offs and synergies of ecosystem services (ESs) at the county scale in the Zhengzhou metropolitan area and constructs an ecological security pattern. Using the InVEST model, we quantified carbon storage (CS), soil conservation (SC), habitat quality (HQ), water yield (WY), and food production (FP). We then analyzed their trade-offs and synergies using the geographically weighted regression model, identified driving factors with an optimal parameter-based geographical detector model, detected ecosystem service bundles via a Self-organizing map model, and constructed an ecological security pattern based on circuit theory. The results showed that: (1) From 2003 to 2023, ES spatial distribution remained stable overall, with weak trade-offs and synergies. Locally, WY and HQ declined, while SC and FP increased. (2) Slope and DEM enhanced SC, whereas urban expansion consistently weakened CS, HQ, and FP. Moreover, slope played an increasingly prominent role in regulating WY. (3) Key synergistic bundles with stable spatiotemporal distribution were identified as ecological sources, leading to the construction of ecological security pattern characterized by “four districts, one corridor, and one belt.” This provides a framework for integrating ecological space protection and restoration into urban development. Full article

Vascularization remains a central challenge in thick tissue engineering. Building on our prior demonstration that carbonate buffer concentration governs multi-channel collagen gel (MCCG) architecture and perfusion culture performance, this study aimed to establish non-contact, orthogonal control of pore size and density in riboflavin-sensitized Type I collagen hydrogels via UV irradiation intensity and preparation temperature. UV intensity was modulated by varying the source-to-sample distance (25–52 mm); preparation temperature was set at 5, 25, or 40 °C; gelation kinetics were quantified using a vial-tilt assay. Pore area fraction ranged from 0.9% to 8.6% and Young’s modulus from 16 to 49 kPa depending on UV dose. Higher preparation temperatures accelerated gelation and produced smaller, more densely distributed pores, consistent with kinetically arrested phase separation. NIH/3T3 fibroblasts cultured on intermediate- and low-intensity UV scaffolds achieved >80% confluency by Day 7, with three-dimensional tissue-like organization and directionally aligned cellular bundles within large pores; cell metabolic activity, assessed by CCK-8 assay, remained consistently high throughout the culture period. These results demonstrate that UV irradiation intensity and preparation temperature are independently tunable, non-contact parameters for reproducible fabrication of collagen scaffolds with tunable vascular-like pore networks, complementing and extending the chemical (buffer concentration) design space of MCCG-based perfusion culture systems. Full article

Multimode fibers (MMFs) have been a key component in short-reach transmission systems for over 50 years and remain the predominant transmission medium for Vertical Cavity Surface-Emitting Laser (VCSEL)-based short links in data centers. To meet the growing demand for higher data rates, MMFs have continuously evolved to enhance bandwidth performance. This paper provides an overview of the fundamental properties of MMFs, with an emphasis on fiber parameters that influence bandwidth capabilities. We discuss trends in increasing data rates for MMF transmission systems in data centers and review recent progress in MMF technology aimed at boosting bandwidth. In particular, we highlight innovative fiber designs, including high-bandwidth 50 μm MMFs, large-core MMFs, long-wavelength MMFs, universal fibers, MMF bundles, and multicore fibers. Full article

Background/Objectives: Temporal predictability may sharpen our ability to distinguish similar sounds, but whether this relies on attention is unclear. This study examined how temporal structure influences frequency discrimination. Methods: Thirty-six adults completed active (attend) and passive (ignore) listening tasks across three paradigms that varied in temporal structure: oddball (isolated deviants), two-tone frequency discrimination paradigm (pairs comparison), and local irregularity of the local/global paradigm (five-tone sequences, bundles). Stimuli varied in difficulty via small or large frequency deviations. Behavioral responses and subjective ratings were collected during active and passive listening. EEG was recorded to assess mismatch negativity (MMN) (either early MMN (eMMN) or mismatch response (MMR)) and P300 event-related potentials. Results: Under active listening, temporal predictability significantly improved performance, but only for difficult discriminations. The local-irregularity condition yielded higher hit rates and greater perceptual sensitivity (d’) than the other paradigms. This benefit was accompanied by enhanced P300, yet participants rated the conditions as equally difficult, indicating no metacognitive awareness. Under passive listening, predictability helped only for easy stimuli, marked by a larger MMR. No reliable change-detection response occurred for difficult sounds when attention was diverted. Conclusions: These findings suggest that the combination of temporal predictability and repeated standard presentation in the local irregularity paradigm can improve frequency discrimination under challenging, attended conditions, with some evidence for partial dissociation between objective performance and subjective awareness. However, substantial individual variability and cross-paradigm confounds caution against strong causal claims. These results are broadly consistent with predictive coding frameworks but require replication with counterbalanced designs and larger deviant trial counts. Full article

Deposits of insoluble protein plaques, which are mostly composed of fibrils from disease-specific amyloid proteins, are histological markers of various human disorders. These range from non-neuropathic amyloidosis such as light chain amyloidosis or type II diabetes to well-known neuro-degenerative diseases such as Alzheimer’s Disease and Parkinson’s Disease. There are indications that these types of fibrillar suprastructures display biological activity distinct from the individual fibrils they are composed of. Yet, little is known about the mechanisms underlying the assembly of fibrillar suprastructures. An understanding of secondary fibril self-assembly into mesoscopic and macroscopic suprastructures is also critical for their application as novel biomaterial. The paucity of experimental data and theoretical models on fibrillar supra-assembly likely relates to the experimental and conceptual challenges in following this type of assembly on multiple length- and timescales, and in characterizing the distinct morphologies formed. Here, we report that the amyloid dye thioflavin T (ThT) is augmented during self-assembly of isolated lysozyme fibrils. We provide evidence that this augmentation of ThT fluorescence results from the unquenching of fibril-bound ThT during fibril binding. Combining ThT fluorescence, optical density, and fluorescence quenching kinetics with optical and electron microscopy, we propose that fibril self-assembly is driven by a transition from reaction-limited ordered assembly to diffusion-limited random cross-linking of fibrils. Full article

Light and drought antagonistically regulate stomatal movement, yet the mechanisms for integrating these conflicting signals remain unclear. In this study, the stomatal aperture and photosynthetic parameters under red light (RL), blue light (BL), and white light in different water regimes were evaluated. Transcriptome analysis was conducted during a 0–6 h period of BL exposure, with or without drought, to explore the molecular mechanisms underlying BL and drought-mediated stomatal movement. Under non-drought conditions, BL significantly enhanced stomatal conductance, transpiration rate, and stomatal aperture. After drought stress, BL-treated seedlings exhibited the greatest reductions in these indicators. Transcriptomic analysis revealed that both BL-responsive genes and drought-responsive genes were significantly enriched in overlapping pathways related to plant hormone signal transduction, and biological processes of water/fluid transport. Among these, the aquaporin gene CsPIP2;3 was identified as a core node in the crosstalk between BL and drought signals, and a potential key regulator of stomatal movement. Tissue-specific expression analysis showed its highest expression in mature leaves; GUS staining further confirmed its expression in guard cells and vascular bundles, while subcellular localization verified the plasma membrane localization of its encoded protein. The transcriptomic data provide novel insights into the mechanisms underlying stomatal movement regulated by BL and drought. Full article

Kappa-carrageenan (κ-CRG) forms thermo-reversible physical hydrogels via a coil–helix transition and helix bundling, but its sulfate-driven electrostatic repulsion limits mechanical robustness and control over aqueous disintegration. Here, we show that plant-derived polyphenols reprogram κ-CRG gel through sulfate-directed binding in a structure-dependent manner. Tannic acid (TA) selectively engages κ-CRG sulfate groups, yielding transparent gels and a >5-fold increase in storage modulus, whereas the same TA triggers turbidity and precipitation in sulfate-free agarose, supporting sulfate-mediated specificity. Using monomeric pyrogallol as a galloyl analogue, we demonstrate that monovalent interactions partially reinforce κ-CRG but lack cooperative stabilization. Intervention timing further separates mechanism. Pyrogallol produces pathway-dependent mechanics and gelation temperature, while TA is stage-insensitive, consistent with multivalent network annealing. In simulated gastric/intestinal fluids, pyrogallol/κ-CRG gels retain morphology longer, whereas TA/κ-CRG ones disintegrate rapidly yet exhibit strong adhesion to rough substrates and human skin. These findings provide a fully food-grade route to tune κ-CRG mechanics, thermal behavior, adhesion and programmed disintegration. Full article

Background: Left bundle branch block (LBBB) and QRS prolongation are markers of electrical dyssynchrony in heart failure, but they do not fully reflect its mechanical consequences. Myocardial work (MW)-derived indices may provide a more comprehensive assessment of left ventricular (LV) mechanical dyssynchrony. We evaluated associations between LV MW parameters, QRS duration, and LBBB in patients with heart failure with reduced ejection fraction (HFrEF) referred for ICD/CRT implantation. Methods: In this single-centre observational cross-sectional study, 96 consecutive patients referred for ICD or CRT implantation were screened. All patients underwent standardized baseline comprehensive echocardiography followed by advanced MW analysis. Myocardial work index (MWI) dispersion was assessed using two complementary methods. MWI dispersion (SD) was calculated as the standard deviation of segmental MWI values across all LV segments, and MWI dispersion (IQR) was defined as the interquartile range (IQR) of segmental MWI values. We evaluated the associations between QRS duration and MW-derived dyssynchrony parameters (individual and composite), as well as their discriminative performance for LBBB. Seven patients were excluded from further analysis due to inadequate echocardiography image quality. Results: The final study group comprised 89 patients with HFrEF (median age 65.5 years), of whom 67.4% were assigned to CRT. LBBB was present in 41.6%, and the median QRS duration was 142 ms (112–162). All analyzed LV MW indices were significantly associated with QRS duration (all q < 0.01). The strongest correlations were observed for MWI dispersion (IQR) (r = 0.58), peak strain dispersion (PSD) (r = 0.54), lateral–septal work asymmetry (r = 0.53), and MWI dispersion (SD) (r = 0.52) (all q < 0.0001). All MW indices differed significantly between patients with and without LBBB (all q ≤ 0.0001). MWI dispersion (IQR) showed the best single-marker discrimination of LBBB (AUC = 0.852). Composite indices achieved AUC = 0.84 but did not significantly improve discrimination versus MWI dispersion (IQR) alone. Conclusions: Myocardial work-derived indices of left ventricular dyssynchrony are strongly associated with QRS duration and the presence of LBBB in patients with HFrEF. Among them, MWI dispersion (IQR) was shown to be the best-performing MW marker for identifying LBBB. These findings suggest that MW dispersion may serve as a robust echocardiographic marker of mechanical dyssynchrony and warrants further investigation as a potential tool for predicting CRT response. Full article

Background/Objectives: We developed a telehealth-enabled fiber-bundle endomicroscopy platform and evaluated its preclinical feasibility for targeted fluorescence imaging in cervical cancer models. Methods: The platform integrates a portable fiber-bundle endomicroscopy (FBE) system, fluorescein isothiocyanate (FITC)-labeled candidate peptides, and a secure web-based telehealth platform for remote consultation. The FBE probe achieved a field of view of 1,700 µm and a lateral resolution of 4 µm, enabling cellular-level fluorescence imaging in a compact, portable format. Four FITC-labeled peptides (SHS1*, SHS2*, FPP*, and CRL*) were evaluated in A549, SiHa, and CaSki cell lines. Ex vivo testing was performed on commercial cervical tissue-array samples. The telehealth platform was assessed for secure medical-image/video transmission and end-to-end latency in a simulated remote-consultation setting. Results: Among the tested probes, FPP*-FITC and CRL*-FITC showed higher fluorescence-positive fractions in the p16-overexpressing cervical cancer cell lines than in the A549 comparator line, with the strongest signals observed in CaSki cells. In ex vivo testing, CRL*-FITC generated higher fluorescence intensity in malignant cervical tissue-array samples than in non-malignant comparator tissues, with a reported 4.6- to 7.4-fold difference in mean signal intensity (p < 0.001). The telehealth platform supported the secure transmission of medical images and video and demonstrated an end-to-end latency of <500 ms in a simulated remote consultation setting. Conclusions: These results support the technical and preclinical feasibility of integrating targeted fluorescence imaging, portable fiber-bundle endomicroscopy, and telehealth into a single platform. This study should therefore be interpreted as a preclinical feasibility study evaluating optical, molecular, and telehealth integration, rather than as a clinically validated cervical cancer screening test. Full article