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Electrode selection and its effects are extremely crucial to characterize the electrical properties and understand the colossal permittivity response of CaCu 3 Ti 4 O 12 (CCTO) ceramics. However, the specifical correlation between metal electrode and electrical performances of CCTO ceramics are not clear so far. In this study, we have systematically investigated the effects of metal electrodes (Ag, Au and Pt) on the colossal permittivity response, dielectric loss, nonlinear characteristics and dielectric relaxation behavior of CCTO ceramics prepared via solid-state reaction means. Moreover, the related physical mechanisms of electrode effect on the electrical properties of CCTO ceramics have been analyzed. As a result, it is found that the metal electrode plays a minimal effect on the dielectric constant of CCTO ceramics in low and intermediate frequencies (102–105 Hz), but the Pt-CCTO ceramic presents a reduced dielectric constant in a frequency range of 104–105 Hz due to the relatively weaker grain boundary responses and the lower Schottky barriers between Pt electrode and sample surface. Meanwhile, the dielectric constant of Pt-CCTO ceramics sharply decreases at the high frequencies, which may be attributed to the greater dipole-dominated dielectric relaxation behaviors induced by the Pt electrode. Furthermore, the influence of electrode on dielectric loss is relatively significant, especially at the intermediate and high frequencies under high temperatures. Whereas, the influences of electrode effect on the breakdown electric field strength and nonlinear coefficient of CCTO ceramics are relatively little, as revealed by nonlinear characteristics. Consequently, it is comprehensively considered that the Ag electrode is more suitable to characterize the electrical performances of CCTO ceramics. Our results may provide a guidance to select electrodes and further understand the colossal dielectric mechanism for all the dielectric ceramics. [ABSTRACT FROM AUTHOR]

Carbamazepine (CBZ) is a widely used anticonvulsant drug that has been detected in aquatic environments. This study investigated the toxicity of its by-products (CBZ-BPs), which may surpass CBZ. Unlike the previous studies, this study offered a more systematic approach to identifying toxic BPs and inferring degradation pathways. Furthermore, quadrupole time-of-flight (QTOF) and density functional theory (DFT) calculations were employed to analyze CBZ-BP structures and degradation pathways. Evaluation of total organic carbon (TOC) and total nitrogen (TN) mineralization rates, revealed carbon (C) greater susceptibility to mineralization compared with nitrogen (N). Furthermore, three rules were established for CBZ decarbonization and N removal during degradation, observing the transformation of aromatic compounds into aliphatic hydrocarbons and stable N-containing organic matter over time. Five potentially highly toxic BPs were screened from 14 identified BPs, with toxicity predictions guiding the selection of commercial standards for quantification and true toxicity testing. Additionally, BP207 emerged as the most toxic, supported by the predictive toxicity accumulation model (PTAM). Notably, highly toxic BPs feature an acridine structure, indicating its significant contribution to toxicity. These findings offered valuable insights into the degradation mechanisms of emerging contaminants and the biosafety of aquatic environments during deep oxidation. [Display omitted] • The rules of CBZ decarbonization and nitrogen removal during UV/H 2 O 2 were deduced. • Key by-products were quantified on concentration and toxicity. • Acridine structure was the main toxic contributor. • Carbon was more likely to be mineralized than nitrogen during degradation. • The degradation pathways were obtained by combing N-transformation and DFT. [ABSTRACT FROM AUTHOR]

The carbon-nylon hybrid fibers were employed to modify the silica sol shell for investment casting, and these shells were sintered in vacuum. An optimized mixing process was applied to improve the dispersion of hybrid fibers in slurry, then resulting in the excellent slurry uniformity. The modified shell fabricated by slurry with 4 g/L hybrid fiber displays a higher sintered strength of 5.46 MPa, which is derived from the increased crack propagation path and the dissipated more loading energy through interfacial debonding and friction of the remained carbon fiber pull-out. In addition, the permeabilities of silica sol shells are obviously improved due to the existence of holes in matrix resulted from the melting of nylon fibers during the sintering process. Also importantly, the hybrid fibers modified shell exhibit a good heat transfer efficiency, which is related to the formed heat transfer channels caused by the remained carbon fibers in sintered shell. • An effective mixing process was applied to achieve the uniform distribution of hybrid fibers. • The carbon-nylon hybrid fibers modified ceramic shells were sintered in vacuum. • The 4 g/L hybrid fibers modified shell exhibits an enhanced green strength of 4.2 MPa and sintered strength of 5.46 MPa. • The shell showed a strengthening heat transfer with the addition of hybrid fibers. [ABSTRACT FROM AUTHOR]

• POM can reproduce the hemodynamic changes of coiled aneurysm. • Neck, pre- and postoperative inflow areas were related with aneurysm recurrence. • A large postoperative inflow area independently predicts the recurrence of coiled PAs. This study aims to investigate recurrence risk factors of simply coiled unruptured paraclinoid aneurysms based on a porous medium model (POM). Twenty unruptured coiled paraclinoid aneurysms with digital subtract angiography (DSA) follow-up were enrolled to analyze morphological and hemodynamic variables to predict recurrence. Recurrent aneurysms have larger neck areas than stable aneurysms (34.43 ± 21.46 mm2 vs. 16.12 ± 7.10 mm2; p = 0.048). For hemodynamic variables, recurrent aneurysms had larger preoperative (16.40 ± 11.38 mm2 vs. 7.87 ± 3.75 mm2; p = 0.048) and postoperative inflow areas (14.07 ± 6.80 mm2 versus 6.73 ± 4.20 mm2; p = 0.021) than the stable group. Only the postoperative inflow area (p = 0.031, OR = 1.289; 95% CI 1.024–1.624) was an independent predictor of recurrence after multivariate regression analysis. The receiver operating characteristic (ROC) curve analysis efficiently predicted recurrence (AUC = 0.833, p = 0.021) with an inflow area cutoff value (9.15 mm2; sensitivity, 0.833; specificity, 0.857). Neck area along with pre- and postoperative inflow areas were associated with aneurysm recurrence. These findings suggest that a large postoperative inflow area independently predicts the recurrence of coiled paraclinoid aneurysms. [ABSTRACT FROM AUTHOR]

The creep behavior of silica-based ceramic cores significantly impacts dimensional precision in investment casting. This study focuses on synthesizing an alumina coating on fused silica surfaces to create a shell-core structure. The creep behavior of silica-based ceramic cores was explored. Specifically, the influence of the shell-core structure on their creep mechanism was investigated. The results revealed the excellent creep resistance of silica-based ceramic cores with shell-core structures. The softening deformation of particles and the viscous flow of the glass phase were observed to account for the differences in creep behavior. The alumina shell structure reinforced the powders, effectively inhibiting the softening deformation of the core structure. Notably, the shell-core structure not only suppressed the viscous flow of the glass phase, thereby weaking the pore filling process, but also promoted the mullitization reaction. This reaction accelerated the consumption of the glass phase, enhancing the creep resistance of the silica-based ceramic cores. [ABSTRACT FROM AUTHOR]