Search Results (270)

To improve the resistance of reinforced concrete (RC) plates against combined blast and fragment loading, the effectiveness of engineered cementitious composite (ECC) protective layers was investigated. Existing studies have mainly focused on single loading conditions, while the coupled effects and the influence of key ECC design parameters remain insufficiently understood. In this study, validated numerical models were developed to examine the effects of ECC thickness, compressive strength, and protective configuration on the structural response. The results show that ECC protection significantly mitigated damage and deformation, identifying thickness as the dominant factor. As the ECC thickness increased, the cratering area decreased from approximately 650,000 mm² to nearly zero, and the central displacement was reduced from 32.2 mm to 18.7 mm (≈42% reduction). In contrast, increasing compressive strength from C30 to C70 resulted in only a limited reduction in displacement (26.6 mm to 23.9 mm). Regarding configuration, double-sided protection further reduced displacement to 19.7 mm (≈39% reduction) and effectively suppressed damage on both surfaces. Overall, the protective performance of ECC layers is governed primarily by thickness and configuration rather than compressive strength. These findings provide quantitative guidance for the design of ECC-strengthened RC structures under combined blast and fragment loading. Full article

Induced resistance primes host immunity for enhanced protection; however, how pathogens respond to this primed state remains poorly understood. Here, we investigated the molecular responses of the rice blast fungus Magnaporthe oryzae during infection of benzothiadiazole (BTH)-primed rice. Seed priming with BTH conferred long-lasting resistance against M. oryzae at the four-leaf stage. Time-course transcriptomic analyses (12–48 hpi) identified 699 differentially expressed genes (DEGs) in M. oryzae, revealing a distinct temporal transition during infection of BTH-primed rice. The fungal transcriptional response shifted from early growth and environmental sensing to enhanced protein turnover, metabolic repression, energy depletion, and genomic instability, indicating progressive impairment of fungal fitness by host immunity. From these DEGs, eight BTH-suppressed candidate virulence genes (MoBVG1–8) were selected for functional characterization. Gene overexpression analyses showed that two genes, MoBVG2 and MoBVG6, significantly increased pathogenicity on BTH-primed rice, while knockout analyses confirmed that both are required for full pathogenicity on non-primed control plants. MoBVG2 encodes a reactive oxygen species (ROS)-scavenging effector, and MoBVG6 encodes an environmental sensor, highlighting the importance of ROS detoxification and environmental perception for successful host colonization. Functional analyses further revealed that MoBVG2 contribute to vegetative growth, while MoBVG6 is required for proper appressorium development. Together, these findings suggest that BTH-induced resistance restricts blast disease by impairing fungal metabolic fitness and suppressing key virulence genes, providing novel insights into the pathogen-side molecular mechanisms underlying chemically induced resistance in plants. Full article

Explosive ordnance (EO), including AXO (abandoned explosive ordnance), IEDs (improvised explosives devices), and UXO (unexploded ordnance), are widely recognised for their blast and fragmentation hazards, but they also represent a persistent and under-addressed source of occupational chemical exposure for explosive ordnance disposal (EOD) personnel. EOD core activities liberate mixed metals and energetic chemicals, resulting in exposures that are multi-route (inhalation of dusts and fumes, dermal loading amplified by sweat and glove occlusion, and ingestion via hand-to-mouth transfer during eating, drinking, or smoking) and multi-temporal (repeated low-dose background plus task-driven spikes), as well as chemically complex. Clinically, this can present as syndromic overlap across acute and chronic domains, with symptoms that are easily misattributed to heat stress, dehydration, infection, or fatigue. Acute effects of concern include neurotoxic presentations (headache, dizziness, confusion, tremor, and seizure), respiratory and mucosal irritation following dust or fume events, gastrointestinal symptoms, and patterns suggestive of acute hepatic or renal stress, particularly when high-intensity tasks occur in hot environments that compound physiologic strain. Chronic outcomes relevant to repeatedly exposed EOD personnel include renal function decline, neurocognitive effects that can degrade operational decision making and safety, persistent haematologic abnormalities, and endocrine disruption signals, with long-latency risks requiring cautious interpretation given sparse longitudinal data and confounding co-exposures. This review synthesises the current evidence base through an EOD lens and translates it into pragmatic clinical and programmatic actions: task-based exposure characterisation; tiered biomonitoring and medical surveillance aligned to operational tempo; incident-triggered assessment pathways after high-residue events; and prevention strategies that work under field constraints, including contamination control zones, hygiene enforcement, glove and respiratory protection optimisation, tool and vehicle decontamination, and measures to prevent secondary transfer and take-home exposure. The central takeaway is practical: EOD programs can reduce morbidity and improve readiness by treating explosive ordnance as a chemical mixture exposure problem, adopting mixture-aware clinical triage, and embedding surveillance and controls that match how EOD work is actually performed. Full article

To address the critical challenges of lithology acquisition and low blasting refinement under extreme low temperatures and varying thermal conditions in high-altitude environments, this study develops a real-time dynamic identification method for rock-like interfaces using Measurement While Drilling (MWD) technology. The scope of this research involves the use of a self-developed indoor digital drilling experimental platform to simulate both ambient and freezing (−20 °C) conditions. Procedures included conducting comprehensive comparative drilling experiments on various rock-like materials with distinct strength levels to evaluate their mechanical responses during penetration. The major findings reveal a significant influence of low-temperature hardening effects on MWD parameters; specifically, the frozen state notably increases drilling torque and feed pressure while simultaneously decreasing the stable rotational speed of the drill bit. To resolve the feature parameter drift induced by temperature variations, a novel interface recognition algorithm is proposed that integrates Z-score normalization, change-point detection, and multi-dimensional spatial clustering. Through a dual-detection mechanism involving both single-point and cumulative features, the algorithm effectively captures precise mutation information during rock layer transitions. It further incorporates multi-dimensional indicators, such as consistency, change intensity, and point density, to perform comprehensive weighted scoring. Experimental results demonstrate that the proposed algorithm effectively eliminates the systematic offset of parameters caused by temperature fluctuations. The prediction error at both “strong-weak” and “weak-strong” transition interfaces is maintained within 1.5 mm, which significantly improves the accuracy and robustness of interface recognition under complex and varying working conditions. These key conclusions provide essential technical support for the implementation of differentiated charging and green refined mining operations, ensuring greater energy efficiency and environmental protection in cold-region engineering. Full article

Tunnels are critical components of transportation networks. Explosions caused by accidents or terrorist attacks can severely damage tunnel linings and even cause structural collapse. This paper develops the validated simulation model for single-channel tunnels into a twin-channel tunnel model. Subsequently, a simulation study investigates the damage state and vulnerability of the twin-channel tunnel under single-sided internal blasting. The results suggest that the supporting effect of the soil can improve the blast resistance of the outer wall of the tunnel. An explosion within a single channel can induce changes in the relative bearing capacity of the twin-channel lining. Under the influence of earth pressure, the relative bearing capacity of the twin-channel lining is further weakened, thereby affecting the overall failure state of the tunnel. Longitudinal plastic strain is primarily distributed at the ends and center of walls and floors, and it spreads as the charge mass increases. The charge location has a significant impact on the damage state of the outside walls of the uncharged channel of the tunnel. Placing explosives on tunnel walls will increase the damage level of the twin-channel tunnel. When the charge weight exceeds 1000 kg and 3000 kg, respectively, the exceedance probability for minor damage and severe damage to the tunnel approaches 1. The strengthening of the blast protection level of the center wall is the key to preventing tunnel collapse. Full article

Sandwich structures with lattice cores are promising for blast protection, yet conventional uniform lattices (ULs) often exhibit limited energy absorption under impulsive loading. This work introduces a novel sandwich panel containing Stretching–Bending Synergistic Lattice (SBSL) cores, and the blast-resistance performance is investigated by finite element modeling (FEM). The results show that the areal specific energy absorption (ASEA) of the SBSLs cored with the same relative density exceeds that of ULs cored by up to 20%. Compared to the cored ULs, the cored SBSLs exhibit significant enhancements in total energy absorption (EA), with improvements of up to 8% for the core itself and 54.7% for the front face plate. Furthermore, the effect of geometric parameters on blast performance is systematically analyzed. The results indicate that reducing the rod diameter of the core cell and thickness of the face plate contributes to higher ASEA, while decreasing the cell height and thickness effectively suppresses the maximum instantaneous displacement (MaxD) of the back face plate. Finally, to further improve the performance, multi-objective optimizations are carried out. The results show that, compared with the baseline model, the MaxD of the optimized structure is reduced by 45%, while the ASEA is increased by 23%. This study demonstrates the significant potential of the SBSL core sandwich panel on blast-resistant protection applications. Full article

In many densely populated towns and semi-urban areas, masonry buildings often stand close to busy roads, exposing them to blasts from improvised explosives or other localized sources. Such structures are rarely designed to resist sudden explosive forces, making severe damage or even progressive collapse likely. Even moderate-intensity blasts can weaken walls, endanger occupants, and cause significant property loss. Unlike reinforced concrete, masonry is highly susceptible to explosive impact. Therefore, understanding how these buildings behave under blast loads and developing affordable protection methods is crucial. Low-rise unreinforced masonry (URM) structures, usually up to about 13 m in height (roughly 2–4 stories), common in villages, semi-urban regions, and conflict-prone zones, are particularly at risk. In many areas, these poorly constructed buildings lack proper engineering design and are therefore highly vulnerable to blast damage. Non-load-bearing internal dividers and perimeter enclosures are especially prone to lateral displacement, which can initiate instability and, in severe cases, lead to overall structural failure. This research focuses on reducing catastrophic damage in URM walls when exposed to close-proximity blast forces using concrete-based protective coatings, both with and without embedded steel-welded wire mesh. The study references a previously tested laterally supported clay brick wall built with cement–sand mortar as the baseline model, with its behavior validated against experimental findings from existing literature. Two blast cases were considered corresponding to scaled stand-off distances of 2.19 m/kg^1/3 and 1.83 m/kg^1/3, representing moderate flexural-shear cracking and full structural failure, respectively. To replicate the observed behavior, a comprehensive 3D numerical simulation was developed using the ABAQUS/Explicit 2020 solver. The model’s predictions were benchmarked and verified through comparison with reported test data. While both blast intensities were used to confirm computational accuracy, the effectiveness of UHPC and UHPFRC protective coatings with and without embedded wire mesh was specifically evaluated under the more severe collapse scenario (Z = 1.83 m/kg^1/3). Results indicated that at a scaled distance of 1.83 m/kg^1/3, the uncoated URM wall could not withstand the blast because of poor tensile and bending capacity. In contrast, the UHPC- and UHPFRC-coatings provided improved confinement and better stress distribution. When welded wire mesh was embedded, crack control improved further, the interface bond strengthened, and a larger portion of blast energy was absorbed and dissipated. Full article

This study proposed an innovative assembled blast-resistant composite structure integrating ultra-high performance concrete plates and ceramic foam layers, designed to enhance blast protection for a power valve hall hole blocking system. Based on the full-scale blast test and numerical simulation, the dynamic response of the structure under blast load was revealed. The parametric studies showed that when the thickness of the UHPC ribbed plate was increased from 30 mm to 40 mm, the maximum displacement at the edge of the hole was reduced by 60.9%. However, a further increase in thickness to 50 mm led to an increase in the inertia effect due to the high stiffness, resulting in a reduction in the maximum displacement value by only 8.61%. In addition, a machine learning framework combining generative adversarial networks (GANs) and Extremely Randomized Trees (ERT) model was constructed to predict the maximum displacement of the structure under blast loading. Furthermore, interpretability analysis by the (SHapley Additive exPlanations) SHAP algorithm verified the consistency of the decision logic of the ERT model with the physical mechanism of the explosion. This study established a full-chain design framework of structural design, mechanism research and intelligent prediction, which provided theoretical support and an intelligent tool system for protection engineering. Full article

Background/Objectives: Blast-induced hearing loss (BIHL) is a major concern, particularly for military personnel, and is linked to impaired auditory neuron survival and synaptic plasticity. This study investigates the potential of the TrkB agonist 7,8-dihydroxyflavone (7,8-DHF) to reduce the severity of BIHL and promote recovery in a mouse model. Methods: Eight-week-old male C57BL/6J mice were used. A custom-built, compressed air-driven system utilizing a modified paintball apparatus was employed to deliver controlled unilateral double blasts (~22 psi exposure pressure) to the left ear. The blasts were administered 30 min apart. Immediately following the second blast, mice received either 7,8-DHF (10 mg/kg) or vehicle (10% DMSO) via intraperitoneal injection. Auditory brainstem responses (ABRs) were measured in both ears at baseline (pre-blast) and at several post-exposure time points. Results: The consecutive blast exposure induced a significant elevation in ABR thresholds, indicative of hearing loss, in both the ipsilateral (exposed) and contralateral (unexposed) ears of vehicle-treated mice. Notably, mice treated with 7,8-DHF demonstrated a marked improvement in hearing recovery compared to the vehicle group. Significant reductions in ABR thresholds were observed in the ipsilateral ear at 4 weeks post-blast (p < 0.0001) and in the contralateral ear as early as 1-week post-blast (p = 0.0236). However, the recovery was partial, with ABR thresholds plateauing after 4 weeks. Conclusions: A controlled blast model demonstrates that systemic administration of the TrkB agonist 7,8-DHF exerts a protective effect, partially restoring auditory function after blast injury. This supports the therapeutic potential of targeting the BDNF-TrkB signaling pathway for managing BIHL. Full article

This study investigates the mechanical performance and blast resistance of high-performance aramid, carbon, and ultra-high molecular weight polyethylene (UHMWPE) fiber fabrics, responding to the need for lightweight and flexible materials in anti-explosion containers for aviation and critical infrastructure. The experimental methodology integrated quasi-static and dynamic tensile tests to characterize the strain-rate effect, followed by near-field air blast tests on both single-material and hybrid multi-ply fabric specimens to analyze their dynamic response, failure modes, and overpressure attenuation. Key findings revealed that carbon fabric exhibited high stiffness but was strain-rate insensitive and susceptible to brittle perforation failure, whereas aramid and UHMWPE fabrics demonstrated strain-rate sensitivity, with UHMWPE showing superior ductility and energy absorption. The hybrid multi-ply configuration (A-C-U sequence) achieved the least amount of failure, effectively utilizing the wave impedance of aramid fabric for initial shock reflection, high stiffness of carbon fabric for stress homogenization, and plasticity of UHMWPE fabric for energy dissipation. Additionally, all fabrics attenuated peak overpressure by over 80%, with enhancement observed for increased thickness. The study concludes that the strategic layering of different fabrics creates a synergistic effect, mitigating the weaknesses of individual fabrics and establishing an effective design paradigm for advanced blast-resistant structures, further enhancing the protective performance. Full article

Reinforced concrete (RC) columns, vital components of urban infrastructure, are highly vulnerable to severe damage from contact explosions, posing significant threats to structural integrity and occupant safety. This study presents a rigorous experimental investigation into the dynamic blast response of RC columns and the efficacy of externally bonded Carbon Fiber Reinforced Polymer (CFRP) wraps as a retrofitting solution. Three series of scaled RC columns were subjected to controlled contact explosions using RDX charges of 50 g, 30 g, and 20 g. For each charge level, three configurations were tested: unretrofitted, single-layer unidirectional CFRP (hoop direction), and dual-layer orthogonal CFRP (hoop and longitudinal). A comprehensive instrumentation system, including high-speed cameras, accelerometers, and pressure transducers, captured blast overpressure, crack evolution, and dynamic acceleration. The results demonstrate that CFRP retrofitting substantially enhances blast resistance and structural performance. Peak accelerations were reduced by up to 68%, with the dual-layer configuration achieving the highest mitigation across all charge levels. In terms of damage control, a single CFRP layer reduced spalling height by 65%, while the dual-layer system achieved up to a 75% reduction. Damage depth was also mitigated by up to 60%, highlighting the superior energy dissipation and containment provided by multi-layered CFRP. These findings underscore CFRP’s significant potential as a robust, practical, and scalable retrofitting solution for enhancing the blast resilience of critical infrastructure, contributing directly to improved urban safety and structural protection in blast-prone environments. Full article

The current transition from conventional blast furnaces to electronic arc furnaces is a viable path to reducing CO₂ emissions during steel production. However, this transition of technologies changes the requirements for possible scrap that may be used as a secondary raw material during EAF steel production. Copper is especially challenging, as it remains in the melt, reducing the mechanical properties of the produced crude steel while being lost to any secondary use. Currently, the two main routes to reduce the copper content are X-Ray Fluorescence sorting and manual sorting. We propose a third approach by using computer vision and machine learning methods to detect copper-containing particles in a post-shredder scrap fraction on low-cost and low-powered hardware. Furthermore, this proposed method is robust to environmental factors, such as heavily corroded particles caused by prolonged storage without proper weather protection. This method can effectively reduce the need for expensive XRF equipment or manual sorting. The developed sorting pipeline was examined in an industrial setting through sorting trials and achieved 99.9 wt.% purity in the produced iron fraction at throughputs of over 3 t/h. Full article

Temperate seagrass meadows are foundation habitats, but their communities are hard to census. Here, I provide a first COI environmental DNA (eDNA) metabarcoding snapshot from seawater at a Zostera marina meadow in the Vostok Bay marine reserve (Peter the Great Bay, Sea of Japan). In September 2021, eDNA from two 900 mL replicates of water were filtered, isolated, amplified for the 313 bp COI fragment with dual-index PCR (multiple replicates), and sequenced on Illumina NovaSeq. I obtained 53,666 reads for 176 operational taxonomic units (OTUs). Eukaryota dominated (154 OTUs; 93.7% of reads), while 22 bacterial OTUs comprised 6.3%. The assemblage was largely photosynthetic microeukaryotes, especially diatoms (61 OTUs; 49% of reads), consistent with late-summer productivity. Metazoan detections included a strong signal of the phoronid Phoronopsis harmeri (7511 reads; 14%), diverse invertebrates, and few vertebrate reads (0.5%), indicating limited fish sensitivity of universal COI assays. One abundant OTU was initially assigned to the giant kelp Macrocystis pyrifera but was rejected after additional BLAST and phylogenetic checks, illustrating database-driven misassignments. COI eDNA offers rapid, low-impact screening for marine protected area monitoring, but robust use requires seasonal replication, multi-marker assays, and a curated regional reference library. Full article

One major challenge in optimizing vehicle underbody structures for blast protection is the trade-off between the high cost of physical tests and the limited accuracy of simulations. We introduce a predictive framework that is co-driven by limited physical measurements and systematically augmented simulation datasets. The main problem arises from the complex components of blast impact signals, which makes it difficult to augment the load signals for finite element simulations when only extremely small sample sets are available. Specifically, a small-scale data-augmentation model within the wavelet domain based on a conditional generative adversarial network (CGAN) was designed. Real-time perturbations, governed by cumulative distribution functions, were introduced to expand and diversify the data representations for enhanced dataset enrichment. A predictive model based on Gaussian process regression (GPR) that integrates physical experimental data with augmented data wavelet characteristics is employed to estimate injury indices, using wavelet scale energies reduced via principal component analysis (PCA) as inputs. Cross-validation shows that this hybrid model achieves higher accuracy than using simulations alone. Through the case study, the model demonstrates that increased hull angle and depth can effectively reduce occupant injury. Full article

To evaluate the slip resistance of high-strength bolted friction-type connections subjected to different corrosion-protection treatments, calibration tests were performed on six representative faying-surface conditions: sand-blasted (uncoated), epoxy zinc-rich primer, waterborne inorganic zinc-rich coating, alcohol-soluble inorganic anti-corrosion anti-slip primer, a complete multi-layer protective coating system, and cold galvanizing. Fifteen test groups comprising 45 tensile specimens were examined to determine slip factors, which were then compared with values recommended in domestic and international design standards. The results show that sand-blasted surfaces (W type) exhibit stable slip factors of μ = 0.43–0.45; alcohol-soluble inorganic primer surfaces (S type) provide the highest slip resistance with μ = 0.49–0.51, representing an increase of approximately 13%–18% compared with sand-blasted surfaces; and cold-galvanized surfaces (D type) achieve favourable performance with μ ≈ 0.44. Waterborne inorganic zinc-rich surfaces (A type) yield μ ≈ 0.33, corresponding to a reduction of about 25%, and are suitable for non-slip-critical connections. In contrast, epoxy zinc-rich primers (C type) and complete multi-layer coating systems (X type) present lower slip factors of μ = 0.26–0.28 and μ ≈ 0.23, corresponding to reductions of approximately 35%–45% and about 50%, respectively, indicating that the X-type treatment is unsuitable for slip-critical applications. The influence of bolt diameter is limited, with slip-factor variations within 5%–8% under the same surface condition, and no statistically significant effect confirmed by two-way ANOVA. These findings provide a quantitative experimental basis for the design, classification, and future standardization of friction-type bolted connections with coated faying surfaces. Full article