Search Results (1,223)

Underground tunnel construction projects using tunnel boring machines (TBMs) require a holistic risk perspective. Such projects face various risks arising from social, economic, political, workforce, and regulatory aspects during project execution. It is necessary to develop preventive strategies for managing these risks and thereby ensure timely project delivery, cost efficiency, and safety. In this study, we aimed to develop a comprehensive hybrid decision-making framework for analyzing risks in TBM-based tunnel construction projects. The proposed approach integrates the best–worst method (BWM), data envelopment analysis (DEA) model-based risk assessment, and the preference ranking organization method for enrichment evaluation (PROMETHEE). The BWM was applied to determine the weights of decision criteria with fewer comparisons and improved consistency. Subsequently, the DEA model was then used to compute local risk scores under multiple input and output conditions. Finally, PROMETHEE was employed to analyze the risks based on positive and negative outranking flows. The proposed approach was applied to a realistic metro construction project in Bangkok. The findings indicated that the proposed approach effectively compromised all the decision-making attributes to manage the uncertainties. The proposed methodology can support project managers, stakeholders, engineers, and relevant authorities in identifying high-priority risks and implementing effective mitigation strategies to enhance risk management in tunnel construction. Full article

Monochamus alternatus larvae, as concealed trunk-boring pests, evade conventional insecticide contact due to their cryptic feeding niche. To overcome this limitation, previous studies have engineered strains of the naturally entomopathogenic bacterium Yersinia entomophaga. The lethality of these strains against M. alternatus was enhanced by incorporating extracellular secretion systems and enriching insecticidal proteins within the larval midgut. However, plasmid loss occurs during serial subculturing. Here, we established an engineered strain that expresses the red fluorescent protein gene mCherry to explore the applicability of bacterial conjugation transfer to Yersinia. We then constructed a chromosomally integrated strain (CSLH88-pCHSW) that incorporates extracellular secretion systems. The results of stability assays demonstrated 100% retention of the mCherry and Cry3Aa-T-HasA genes over 78 generations. SDS-PAGE and Western blot analyses confirmed the extracellular secretion of the Cry3Aa-T protein in the CSLH88-pCHSW strain. Bioassays revealed that the CSLH88-pCHSW strain was significantly more virulent against M. alternatus larvae than both the wild-type strain (CSLH88) and the plasmid-transformed strain (CSLH88-pCHKW), and exhibited markedly faster insecticidal kinetics. Our study reveals the application of bacterial conjugation transfer technology for constructing biocontrol strains. This genomically stabilized Yersinia strain eliminates the risks of failure associated with plasmid loss in the field, enabling the sustainable control of M. alternatus. Full article

The Cairo Monorail System presents significant geotechnical challenges due to its integrated structural configuration and its alignment across heterogeneous soil conditions, including collapsible and swelling soils. This study investigates the foundation performance of the monorail through a combination of advanced site investigations, full-scale pile load testing under dry and wetted conditions, and finite-element modeling incorporating soil–structure interaction. Field load tests on large-diameter bored piles founded in collapsible soils demonstrated a pronounced increase in settlement and a reduction in stiffness following wetting, confirming the sensitivity of pile behavior to moisture variations. Three-dimensional numerical analyses of the integrated monorail system showed that differential settlements between adjacent columns are generally limited to less than 9 mm under serviceability loading conditions, satisfying passenger comfort requirements. Long-term coupled seepage–deformation analyses conducted using PLAXIS indicated that surface water infiltration into swelling soils may induce time-dependent monopile heave of approximately 10 mm over a 50-year design life, which remains within acceptable serviceability limits. The results demonstrate that detailed geotechnical characterization, combined with appropriate numerical modeling strategies, can effectively control differential deformation and long-term heave in continuous monorail systems, ensuring their operational safety and long-term performance. Full article

Dimensional verification of turbomachinery rotors requires traceable accuracy on functional data and dense coverage of freeform blades. This study quantifies the expanded measurement uncertainty (U95) for a centrifugal rotor inspected with a bridge-type CMM (Nikon Altera 10.10.8) and a structured-light scanner (ATOS Compact Scan 5M Rev.1), using repeated measurements in accordance with ISO 10360 and ISO 15530-3. The CMM achieved U95 ≈ 4–6 µm on bores, whereas optical scanning yielded U95 ≈ 12–18 µm on freeform blade regions. Cross-system results exhibited systematic offsets, indicating that the two methods are not directly interchangeable in absolute terms. Nevertheless, they are complementary: CMM ensures datum traceability, while optical scanning enables rapid full-field blade assessment, supporting uncertainty-aware hybrid inspection. Full article

Background: Idiopathic developmental intellectual disability (IDID) is a neurodevelopmental disorder that leads to poor health status. This study analyzes the burden of IDID attributed to lead (Pb) exposure in the United States of America (USA) from 1990 to 2023 and projects trends through 2050. Methods: Measurements on Disability-adjusted life years (DALYs) and Years lived with disability (YLDs) were downloaded from the Institute for Health Metrics and Evaluation (IHME). A joinpoint regression model was employed to assess the epidemiological change in this disease. The age–period–cohort (APC) model was used to examine the age, period, and birth cohort effects on DALYs. Decomposition analysis was applied to analyze the role of population, aging, and epidemiological factors in driving changes to DALYs. Bayesian age–period–cohort (BAPC) analysis was conducted to forecast sex-specific burden trends through 2050. Results: From 1990 to 2023, DALYs and age-standardized DALY rate (ASDR) showed an overall decreasing trend. Males bore a higher disease burden than females. In the USA, the average annual percentage change (AAPC) in ASDR was −1.41 (95% CI: −1.45 to −1.37), indicating an overall decline. BAPC analysis predicted that the ASDR will continue to decline for both females and males through 2050, with males showing a faster decline. Conclusions: Consistent efforts have led to significant progress in reducing lead exposure-related IDID in the USA. Prevention strategies focus on continuing to reduce lead exposure and minimize its impact on IDID. Full article

The eccentric permanent-magnet (PM) pole technique is widely recognized as an effective technique for reducing cogging torque in surface-mounted PM motors (SMPMMs). This paper proposes a novel analytical approach based on bilinear mapping to determine the optimal PM reduction parameters. In this method, the outer surface of the PM and the stator inner bore are modeled as eccentric circles. Bilinear mapping is then used to transform a slotted stator bore into an equivalent slotless configuration with small slot-openings, allowing the optimal PM reduction to be identified. The key electromagnetic performance characteristics of SMPMMs—including torque, efficiency, mean air-gap flux density, and related parameters—are formulated as explicit mathematical functions of the PM reduction factor. The influence of the optimal PM reduction on both static and dynamic rotor eccentricity is also investigated. The results reveal that the bilinear mapping equations yield two distinct roots for the optimal PM reduction. Once the optimal values are known for a reference motor, those of other motors with different dimensions can be readily derived by scaling according to the ratio of the outer PM radii, without repeating the full calculation process. The proposed method is applicable to various SMPMM geometries, including radial, parallel, and bread-loaf configurations. Full article

With the rapid advancement in information technology, the digital twin and smart assembly process simulation have become an integral part of the design and manufacturing of high-precision products. However, conventional Tunnel Boring Machine (TBM) cutterhead design and on-site assembly planning remain largely experience-driven and fragmented, with limited interoperability between geological characterization, structural verification, and constructability validation. This study proposes a digital twin-driven framework for TBM cutterhead design optimization and assembly process simulation that integrates geology-aware design inputs, BIM-based information modelling, FEM-based structural assessment, and immersive virtual environments within a unified virtual–physical workflow. To ensure consistent data exchange across platforms, an IFC4.3-compliant ontology is established using a non-intrusive property-set (Pset) extension strategy to represent cutterhead components, geological parameters, FEM load cases/results, and assembly tasks. Tunnel-scale stress analysis and cutter–rock interaction modelling are used to define project-representative cutter loading envelopes, which are mapped to a high-fidelity cutterhead FEM model for iterative structural refinement. The optimized configuration is then transferred to a game-engine/VR environment to support full-scale design inspection and assembly rehearsal, followed by manufacturing and field deployment with bidirectional feedback. To validate the proposed framework, an implementation case study of a deep hard-rock tunnelling project is presented where five design iterations were tracked across BIM–FEM–VR and nine constructability issues detected and resolved prior to assembly. The results indicate that the proposed digital twin approach strengthens traceability from geology to loading to structural response, reduces localized stress concentration at critical interfaces, and improves assembly readiness for complex tunnelling projects. Full article

Quantum computing threatens the security foundations of global financial systems, exposing long-lived data and signed digital assets to “harvest-now, decrypt-later” attacks. While the timeline for cryptographically relevant quantum computers remains uncertain, regulatory signals from the USA, UK, EU, Canada, and Australia converge: financial institutions and payment infrastructures must begin migrating to post-quantum cryptography (PQC) now to preserve confidentiality, integrity, and systemic stability. This paper maps emerging standards and roadmaps, contrasting binding requirements like the EU’s DORA crypto-agility provisions with non-binding guidance from NIST, ENISA, and ETSI. Despite a shared intent to secure high-risk use cases by 2030–2031 and complete migration by 2035, divergences in enforcement and milestones create uncertainty for cross-border banks and financial market infrastructures. In parallel, technical adoption is advancing: major browsers, cryptographic libraries (OpenSSL/BoringSSL), and CDNs (e.g., AWS CloudFront) have deployed hybrid PQC key exchange in TLS 1.3, proving confidentiality defenses are viable at internet scale. The paper synthesizes historical transition lessons, sector-specific regulatory drivers, and operational constraints in payment infrastructures to derive a new, principle-based migration: crypto-agility, risk-prioritized scoping, hybrid deployment, vendor and supply-chain alignment, independent testing, and proactive supervisory engagement. Acting now reduces long-tail exposure and ensures readiness for imminent compliance and interoperability deadlines. Full article

Background: Inadvertent arterial cannulation during central venous catheter placement is a recognized complication with potentially serious consequences, particularly when involving large-caliber catheters. While management strategies have evolved from mandatory surgical repair to various percutaneous approaches, limited data exist regarding collagen-based vascular closure devices for large-bore carotid arteriotomies. Case Presentation: We report the case of a 59-year-old male patient with acute Stanford Type A aortic dissection who underwent emergency surgical repair of the ascending aorta. During central venous cannulation, a five-lumen Certofix Quinto catheter (12-French outer diameter) was inadvertently inserted into the left common carotid artery. Given the complexity of concurrent cardiac surgery and the large-bore nature of the arteriotomy, percutaneous closure with an 18-French MANTA vascular closure device was successfully performed following completion of the aortic repair. The procedure achieved immediate hemostasis without complications. Outcomes: The patient remained neurologically intact throughout a 12-month follow-up period. Serial duplex ultrasonography and computed tomography angiography confirmed carotid artery patency without evidence of stenosis, dissection, pseudoaneurysm formation, or thromboembolic complications. Conclusions: This case demonstrates the technical feasibility of using a collagen-based vascular closure device for percutaneous management of a large-bore carotid arteriotomy in the acute surgical setting. While the outcome was favorable in this patient, this approach represents an off-label application that requires further validation and should be reserved for carefully selected cases in experienced centers where the benefits of percutaneous closure are judged to outweigh the uncertainties of supra-aortic device deployment. Full article

During the excavation of the Guadarrama railway tunnels, part of the Spanish high-speed rail network (AVE), distinct wear patterns were observed among four types of disc cutters employed in tunnel boring machines (TBMs). The central question addressed in this study is whether the differences in wear—specifically in the Abrasivity Value Steel (AVS) recorded for the four cutter types—are attributable to variations in their inherent wear resistance or to the variability of the tested lithologies and the testing procedures. If the latter hypothesis is confirmed, it would imply that substituting one cutter type for another would not result in significant changes in consumption rates, and that the observed variations would be primarily associated with lithological differences rather than cutter design. This paper presents a real case study concerning the selection of disc cutters for two TBMs used in the excavation of the Guadarrama tunnels. The rock mass encountered consisted predominantly of granite and gneiss. Full article

FTIR spectroscopy, attenuated total reflection (ATR), and diffuse reflectance (DRIFT) modalities, along with ICP–AES spectroscopy and correlation analysis, including two-dimensional correlation spectroscopy (2DCOS), were used for the detailed analysis of Kastanozem (chestnut) soils. Microaggregates (20–200 μm) and macroaggregates (200–1000 μm) of characteristic horizons of uncultivated (fallow) and cultivated (arable land) chestnut soils of the same origin were physically fractionated by wet sieving. The combination of these molecular and atomic spectroscopy techniques in combination with correlation analysis was able to find direct correlations between matrix-forming anions and soil organic matter (SOM) of Kastanozems. Humic substances were separated from the corresponding soil samples to reveal SOM contributions more explicitly. Microaggregates of the size fractions of 20–40 μm and 40–60 μm bore the most comprehensive information for both techniques used. Most significant differences between land-use Kastanozem samples were observed in topsoil horizons (arable P versus light-colored humic AJ horizon), and for the next pair of horizons along the profile xerometamorphic BMK horizon to structural metamorphic BM horizon. These differences included carbonate matrix and SOM amounts and composition. Topsoil arable land showed significantly smaller amounts of total organic carbon and a decrease in the share of long-chain hydrocarbons compared to fallow, which has a more distinctive character compared to similar land-use samples of Chernozem. An increase in carbonate contents with soil depth was found for both land-use samples, while the amounts and composition of the silicate matrix remained largely unchanged within the depth profile. The heterospectral 2DCOS comparison of FTIR (between horizons and land-use samples), ICP–AES (between land-use samples), and FTIR–AES (for the same sample) showed the possibility of a more reliable attribution of FTIR absorption bands and revealed the differences in the macro- and micro-aggregate elemental and SOM composition of Kastanozems. Full article

Post-grouting is an active reinforcement technique that can significantly enhance the bearing performance of bored piles. This study conducted field tests on three in situ test piles using tip grouting, side grouting, and combined tip-side grouting. Based on the analysis of static load test data, the improvement effects of different grouting methods on the vertical bearing behavior of the piles were quantified. In situ tests were then performed to elucidate the reinforcement mechanisms of various post-grouting techniques on the pile foundations. Based on the validated finite element model, the study explored the influence of key grouting parameters on the bearing performance of grouted piles. Analysis of the test data shows that all grouting methods improved the vertical bearing capacity of bored piles. The positive effect of tip grouting was more pronounced than that of side grouting. Furthermore, in the clay layer of the soft soil region, side grouting primarily manifested as splitting grouting, while tip grouting formed a hardened grout bulb at the pile tip through cementation and solidification, thereby significantly enhancing the mobilization of the pile tip bearing capacity. Finite element model analysis shows that, in terms of enhancing the bearing capacity of the pile, expanding the grout diffusion range is more effective than increasing the grout material strength. Full article

To enhance intelligent decision-making for tunneling operations in complex geological conditions, this study proposes a high-precision prediction method for TBM cutterhead torque using engineering data from the west return-air roadway of the Shoushan No. 1 Mine in Pingdingshan, Henan (China). A multisource dataset integrating geological exploration data, TBM electro-hydraulic parameters, and surrounding rock–TBM interaction indicators was constructed and preprocessed through outlier removal, interpolation restoration, and Savitzky–Golay filtering to extract high-quality steady-state features. To capture the mechanical properties of composite strata, the equivalent strength parameter of composite strata and an integrity-classification index were introduced as key predictors. Based on these inputs, a hybrid TCN–BiLSTM–Logarithmic Attention model was developed to jointly extract local temporal patterns, model global dependencies, and emphasize critical operating responses. Testing results show that the proposed model consistently outperforms TCN, BiLSTM, and TCN-BiLSTM baselines under intact, transitional, and fractured rock conditions. It achieves an RMSE (19.85) and MAPE (3.72%) in intact strata, while in fractured strata RMSE (29.55) and MAPE (10.82%) are reduced by 23.5% and 22.7% relative to TCN. Performance in transitional strata is likewise superior. Overall, the TCN–BiLSTM–Logarithmic Attention model demonstrates the highest prediction accuracy across intact, transitional, and fractured strata; effectively captures the mechanical characteristics of composite formations; and achieves robust and high-precision prediction of TBM cutterhead torque in complex geological environments. Full article

As China’s urban underground area grows, deep foundation pit projects in complex geological circumstances, particularly near critical infrastructure, must adhere to tight deformation control guidelines. However, limited research has been conducted on the deformation behavior of internal bracing systems in Sichuan’s sandy cobble strata. This research centers on a deep excavation near civil defense facilities in Pujiang County, Chengdu. We investigated the deformation characteristics of retaining piles and internal bracing systems using field monitoring, finite element simulations, and parameter sensitivity analysis, and proposed optimization solutions for the support scheme. Road settlement, pile-head vertical displacement, building settlement, and deep lateral displacement of retaining piles were all monitored in the field at different phases of excavation. MIDAS/GTS was used to generate a 3D finite element model that included bored piles as a contiguous pile wall. The model was verified against monitored data and showed a maximum variation of 3.7%. Parametric studies were conducted to optimize the equivalent stiffness of the contiguous pile wall and the standardized internal bracing system. The findings indicate that the maximum lateral displacement of retaining piles is the primary optimization restriction. Reducing the equivalent stiffness to 0.6t (relative to the baseline thickness t) causes displacement to surpass the warning threshold (35 mm), whereas increasing it to 1.2t or 1.4t limits deformation without incurring significant costs. Case G of the standardized internal bracing system ensures that the maximum pile displacement (21.95 mm) remains below the warning criterion (24.5 mm) while improving constructability. This work elucidates the deformation characteristics of internal bracing systems in sandy cobble strata near sensitive buildings, offering theoretical and practical assistance for comparable projects. Full article

In this study, linear and nonlinear parametric models (M1–M6) were jointly evaluated alongside machine learning (ML)-based approaches to achieve reliable and interpretable prediction of the penetration rate (ROP) of tunnel boring machines (TBMs). The analyses incorporate key geomechanical and structural variables, including the brittleness index (BI), uniaxial compressive strength (UCS), mean spacing of weakness planes (DPW), the angle between the tunnel axis and weakness planes (α), and Brazilian tensile strength (BTS). The coefficients of the parametric models were optimized using the Differential Evolution (DE) algorithm. Variable effects were systematically examined through Jacobian-based elasticity analysis under both original and standardized data scenarios. The results indicate that the M6 model, which explicitly incorporates interaction terms, delivers superior predictive accuracy and a more balanced, physically meaningful representation of variable contributions compared to widely used parametric formulations reported in the literature. While the dominant influence of BI and UCS on ROP is consistently preserved across all models, the indirect contributions of variables such as DPW and BTS are more clearly revealed in M6 owing to its interaction-based structure. Model performance improves systematically with increasing complexity, with the coefficient of determination (R²) rising from 0.62 for M1 to 0.69 for M6. Relative to the linear model, M6 achieves a 9.07% reduction in RMSE and a 10.48% increase in R², while providing additional improvements of 2.47% in RMSE and 2.37% in R² compared with the closest competing model. ML-based variable importance analyses are largely consistent with the parametric findings, highlighting BI and α in tree-based models, and UCS and α in SVM and GAM frameworks. Notably, the GAM exhibits the highest predictive performance under both data scenarios. Overall, the integrated use of parametric and ML approaches establishes a robust hybrid modeling framework that enables highly accurate and engineering-interpretable prediction of TBM penetration rate. Full article