Abstract On-site quality assessment of precast concrete (PC) components is essential to ensure structural integrity, but precamber measurement relies on labor-intensive manual procedures due to time constraints and site congestion. This study proposes an automated precamber estimation framework for PC components using two-dimensional (2D) images. The proposed method integrates a reference-object-free geometric estimation, which utilizes predefined design specifications as ground truth, with vision transformer (ViT)-embedded architecture trained on hybrid synthetic data to robustly capture high-level features. Field validation demonstrated that the framework achieves an average measurement error of 1.91 mm, confirming a reliable performance comparable to manual methods. Notably, the automated process reduced inspection time by 79.82% and labor costs by 91.70% compared to traditional manual procedures. These results demonstrate the practical feasibility of the proposed framework for supporting rapid and efficient on-site quality assessment. Furthermore, the framework holds significant potential to extend into a comprehensive dimensional inspection system for managing various geometric deformations beyond precamber.
The development of energy-efficient and highly sensitive ultraviolet (UV) photodetectors (PDs) is vital for applications in environmental monitoring, biomedical diagnostics, and optical communication. While conventional thin-film devices are limited by low surface area and restricted light absorption, three-dimensional (3D) nanostructures offer a promising alternative by enhancing light-matter interaction and carrier collection. This study introduces a 3D UV photodetector architecture composed of aerosol-printed silver (Ag) mesh combined with seedless hydrothermally grown zinc oxide (ZnO) nanorods (NRs). The aerosol printing process is optimized to form high-aspect-ratio Ag mesh structures on glass substrates, which serve simultaneously as conductive scaffolds and nucleation sites, enabling the direct growth of vertically aligned ZnO NRs. The resulting 3D Ag/ZnO structure forms Schottky junctions that facilitate efficient charge separation and internal gain, thereby enhancing the PDs' performance. Under a low operating bias of 0.1 V and weak UV illumination (1 mu W cm-2), the device exhibits outstanding performance, including a responsivity of 1.2 & times; 103 A W-1, detectivity of 8.52 & times; 1012 Jones, and an external quantum efficiency (EQE) of 4.08 & times; 105%. Additionally, the PDs are tested over a range of temperatures, showing excellent thermal stability. These developments provide a versatile platform to design hierarchical nanoarchitectures for next-generation optoelectronic systems.
This study reports a graphite-core, multiphase gradient C-Si-N composite architecture for Si-containing graphite-based negative electrodes in lithium-ion batteries. The increase in electrode thickness is used as a practical metric of expansion-driven degradation. The composite is prepared by the simultaneous nitridation and carbonization of a graphite core-Si precursor using polyvinylpyrrolidone (PVP) as the N source. Scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy indicates a quasi-continuous radial trend in the relative N signal toward the outer shell, consistent with preferential N enrichment near the particle exterior. This spatially distributed N arrangement may spatially separate the Si-rich expansion-prone region from the carbon-rich exterior containing nitrides and other N-bearing species, thereby enabling stress partitioning. The shell architecture is designed to disperse expansion-induced stress and stabilize the electrode-electrolyte interface. During electrochemical cycling, the C-Si-N electrode with 10% PVP preserves its core-shell morphology and exhibits the smallest average electrode thickness expansion (similar to 58% after 40 cycles, based on four independent cells). The reduced thickness growth is discussed in relation to a mechanically robust Si-N matrix (Si3N4-like/SiNx-like), potential Li-N interphase species, and N-containing carbon, together with the post-mortem morphology and electrochemical impedance evolution. This study presents reduced swelling as an electrode-level trend versus nominal PVP addition, along with associated nitride-related signatures, thereby highlighting spatially graded stress buffering as an electrode-level design principle.
