Search Results (30,546)

Thaumasite sulfate attack (TSA) under elevated water pressure has important implications for the durability of deep underground concrete structures, yet the deterioration process and the coupled effect of water pressure and carbonate supply remain insufficiently understood. In this study, laboratory pressurized sulfate exposure tests were conducted to investigate the evolution of macroscopic performance and microstructure of cement mortars with different limestone powder contents (0%, 15%, and 30%) under water pressures of 0, 2.5, and 5.0 MPa. The results show that elevated water pressure promotes sulfate ingress into the mortar and accelerates later-stage strength loss; this interpretation is supported by the depth-dependent distribution of soluble SO₄²⁻ measured in mortars without limestone powder. Two-way ANOVA indicates that both water pressure and limestone powder content have significant effects on compressive strength, and their interaction becomes statistically significant at 120 d. XRD, FT-IR, and SEM/EDS results show that, under elevated water pressure and high limestone powder content, the corrosion products gradually evolve from gypsum-related products to ettringite- and thaumasite-related products, with a certain spatial differentiation. Specifically, the gray–white, mud-like surface products are consistent with thaumasite-rich assemblages, whereas the needle- and column-like crystals in the interior are consistent with ettringite-rich assemblages. Overall, elevated water pressure mainly promotes sulfate transport, while limestone powder mainly increases carbonate availability. These two factors may jointly intensify TSA deterioration in mortar through a pathway involving transport enhancement, carbonate supply, corrosion product evolution, and aggravated macroscopic damage. This study provides a reference for understanding the sulfate deterioration mechanism of limestone powder-containing cement-based materials in deep underground environments under elevated water pressure. Full article

The accuracy of numerical weather prediction largely depends on the quality of the initial conditions. Global Navigation Satellite System radio occultation (GNSS-RO) observations, with their high vertical resolution, play an important role in reducing initial condition errors. In this study, multiple simulations with different initialization times were conducted during the development of Typhoon BEBINCA using the WRF-GSI assimilation system to evaluate the impact of YunYao GNSS-RO observations on improving extreme weather simulation performance and to investigate the sensitivity of refractivity assimilation to different cloud microphysics parameterization schemes. The results show that assimilating YunYao GNSS-RO data significantly improves the consistency between the model initial fields and observations and enhances the analysis quality in the middle and upper troposphere. Compared with ERA5 reanalysis data, the assimilation experiments better reproduce the spatial and temporal evolution of key atmospheric variables, and the improvements persist from 36 h to 120 h forecast lead time. Statistical results from multiple initializations show that the maximum RMSE reductions exceed 0.2 K for temperature, 0.1 m s⁻¹ for wind speed, and geopotential height shows consistent improvements throughout the entire atmosphere. In addition, the assimilation experiments improve the simulation of Typhoon BEBINCA’s track and intensity. Statistical results from multiple initializations indicate that the 84 h track error is reduced by approximately 30 km on average, and the minimum central pressure bias is also reduced. Sensitivity experiments further show that the WSM6 microphysics scheme performs better in track forecasting, while the Thompson scheme is more suitable for intensity forecasting. Overall, YunYao GNSS-RO assimilation effectively improves typhoon forecast accuracy and demonstrates strong potential for operational applications. Full article

Maritime transport is under increasing pressure to cut greenhouse gas and pollutant emissions to meet global decarbonization goals and tighter environmental standards. Ship electric propulsion systems offer a promising solution for short-range maritime operations, particularly for small vessels and coastal activities. Full-electric vessels can significantly reduce operational emissions; however, a key challenge is the extensive charging time for onboard energy storage, which can affect operational continuity and logistical efficiency. This study examines mission planning and energy management for a hybrid multi-source electric mail boat operating in the Aeolian archipelago. It evaluates the viability and performance of a daily inter-island route powered by a high-temperature methanol fuel cell, batteries, and photovoltaic panels. A routing and simulation framework was developed to model the boat’s itinerary among seven islands, accounting for realistic navigation speeds, scheduled stops, solar energy availability, and battery state-of-charge constraints. The study analyzes distance, travel time, energy consumption, solar power generation, and fuel–electric usage with high temporal resolution, enabling detailed analysis of power flows during sailing and docking. Several operational strategies were assessed, including periods of increased speed supported by battery assistance and fuel–electric cell output, combined with coordinated energy management to keep battery levels above a lower acceptable threshold while completing the route in a single day. The methodology provides a practical tool for planning low-emission island networks and supports the integration of innovative energy systems into small electric workboats operating in specific maritime regions. Full article

There is growing concern that antimicrobial use (AMU) in livestock may contribute to antimicrobial resistance (AMR) in humans and lead to the consumption of animal-derived foods contaminated with antimicrobial residues. As stakeholders in the livestock industry, farmers must participate in the joint effort to reduce AMU. This cross-sectional study, based on a survey questionnaire, was conducted to evaluate the biosafety measures implemented on small ruminant farms and to assess the knowledge, attitudes and practices (KAP) of small ruminant farmers regarding AMU, AMR and residues. The mean biosafety score obtained was 8.4 points on a 0–17 scale. Some biosafety measures appeared difficult to implement, namely vehicle disinfection, requiring visitors to change clothing and footwear at the farm entrance, cleaning and disinfecting farm facilities, using high-pressure washing equipment, and requiring employees to change clothing and footwear upon entering the farm. Although farmers self-reported moderate levels of knowledge (4.9 points on a 0–7 scale) and positive attitudes (5.8 points on a 0–7 scale), significant gaps in knowledge about antibiotics and antimicrobial stewardship persisted. Practices received lower scores (4.7 on a 0–7 scale), especially regarding medication recording, leftover antibiotic management, and waste disposal. Cluster analysis identified distinct farmer profiles with different patterns of knowledge and practices. These findings underscore the importance of considering farmer heterogeneity when designing interventions aimed at improving AMU. Full article

This study investigates methane leakage and diffusion from a buried high-pressure natural gas pipeline (8 MPa, 1000 mm diameter) using CFD simulations with the DES turbulence model. Based on homogeneous and layered soil models, the influences of soil porosity (0.46 to 0.54), particle size (10 μm to 100 μm), and soil stratification on the spatial and temporal characteristics of methane diffusion are systematically explored. The simulation results show that (1) methane diffuses from the leak hole to the surrounding soil in an ellipsoidal pattern, with the fastest diffusion speed along the pipeline’s axial direction. (2) In homogeneous soil, within the range of soil parameter values considered in this study, the absolute changes in risk assessment indices (FDR, GDR) caused by soil particle size were more significant; whereas the relative percentage changes in risk assessment indicators caused by soil porosity were more pronounced. (3) In layered soil, the permeability contrast between adjacent layers creates the permeability discontinuity interface effect. When a fine-grained or low-porosity layer overlies a coarse-grained layer, the upper layer acts as a hydraulic barrier, prolonging FDT from 130 s to 354 s while promoting significant horizontal spread at the interface. Conversely, a coarse-grained or high-porosity upper layer accelerates vertical breakthrough. These findings provide a scientific basis for risk assessment, monitoring site optimization, and emergency response planning, particularly in regions with heterogeneous stratified soils. Full article

To address the issues of sealing leakage and airflow-induced vibration in high-speed turbomachinery, a conical straight-tooth annular clearance sealed hybrid aerostatic/aerodynamic bearing is investigated. A three-dimensional CFD model is established to study the effects of radial clearance height, inlet pressure, rotor speed, and eccentricity on pressure distribution, velocity distribution, and leakage rate. The results show that leakage exhibits a strong positive nonlinear correlation with clearance height and inlet pressure, following a power-law or polynomial relationship, while rotor speed and eccentricity exert negligible effects (less than 5%). The underlying mechanisms are identified as the kinetic energy diversion caused by circumferential shear and the mutual cancelation of throttling and backflow effects. Increasing the gap height enhances leakage by expanding the hydraulic diameter and strengthening vortex disturbance; increasing inlet pressure promotes leakage by elevating the driving force and intensifying local flow separation. Full article

On-orbit space cameras face high heat dissipation and non-ideal thermal contact interfaces. Thermal interface material (TIM) performance affects detector stability and imaging quality. However, traditional fillers are not clearly suitable for large-area, low-pressure, and non-ideal conditions. This paper assumes that embossed indium foil compensates for interface irregularities at micro and macro scales. It thus reduces interface thermal resistance (ITR). We propose embossed indium foil as a TIM. We build an evaluation framework from surface thermal resistance to component-level validation. Experiments are conducted on a steady-state heat flux platform. We measure ITR of four foil thicknesses (0.1–0.3 mm) under different pressures (0.17–1.38 MPa) and temperatures (10–30 °C). Results show strong pressure dependence. At low pressure (<0.6 MPa), thinner foils perform better due to lower bulk resistance. At high pressure (>0.6 MPa) and large area (0.06 m²), thicker foils show advantages. Their higher plasticity better compensates surface errors. Engineering tests confirm the method’s effectiveness. A 0.285 mm embossed indium foil reduces ITR from 3055 to 750 mm²·°C·W⁻¹, a 75.5% reduction. This study proves embossed indium foil fills micro-gaps and compensates macro-shape errors. It provides quantitative support for spacecraft thermal design. Full article

To solve the problems of high injection pressure and low water injection in an ultra-low-permeability reservoir, nanoemulsion was injected to reduce the surface interfacial tension, change the wettability, and achieve the purpose of depressurization. In this paper, the surface and interfacial tension, wettability properties, and particle size distribution characterization of nanoemulsion were determined, and the performance of nanoemulsion was evaluated by laboratory experiments such as core displacement. At the same time, the depressurize and augmented injection mechanism of the nanoemulsion was studied through a scanning electron microscope. The experiment shows that the nanoemulsion system has good compatibility with brine. With the increase in temperature, the surface and interfacial tension does not change, and there is no precipitation. And the system can reduce the oil–water interfacial tension to about 1 mN·m⁻¹ under the best conditions. By measuring the wettability angle of nanoemulsion at the concentration of 0.1% to 0.5%, which can adjust the wettability of the rock surface, the hydrophilicity is weakened. The depressurization performance of nanoemulsion under different injection rates, concentrations, and slug sizes was also compared through core displacement experiments, to provide reasonable experimental support for field operations. In the most reasonable case, the depressurization rate after using nanoemulsion can reach 16.78%. Full article

Wood is a sustainable material, but hygroscopicity can affect dimensional stability and mechanical durability. Recent research has increasingly focused on combining citric acid with various polyols as eco-friendly crosslinking systems to improve wood properties. Herein, a solvent-free and catalyst-free method was used to synthesize bio-based polyesters from citric acid and mannitol. In situ curing was carried out after vacuum-pressure impregnation of fast-growing poplar wood (Populus deltoides Marshall). Morphological characterization showed that the polyester filled the cell lumen and penetrated the cell wall structure. It was confirmed by Fourier Transform Infrared (FTIR) and cross-polarization/magic angle spinning (CP/MAS) ¹³C nuclear magnetic resonance (NMR) analysis that the polyester formed covalent ester bonds with wood hydroxyl groups, which indicated successful chemical grafting. The dimensional stability and mechanical properties of the modified wood were greatly improved. The parallel compressive strength of the grain reached 41.5 MPa, which was 41.7% higher than that of the untreated wood. This research adopted a citric acid–mannitol polyester, providing a sustainable, economical, and scalable approach for the development of high-performance, degradable wood composites for construction/furniture applications. Full article

Urban ecological vulnerability has become an important perspective for understanding ecosystem stability under environmental change. However, its spatiotemporal dynamics and driving mechanisms remain insufficiently understood in high-latitude grassland cities. This study focuses on the central urban area of Hailar and examines how ecological vulnerability evolves and what factors shape its spatial differentiation. Using the sensitivity–resilience–pressure (SRP) framework, a multidimensional evaluation system was constructed based on statistical yearbooks and GIS-based spatial data. Ecological vulnerability was assessed on a 1 km grid from 2010 to 2020, and its evolution was analyzed in three stages. The spatial pattern remains relatively stable but shows increasing differentiation over time. High-vulnerability areas are persistently concentrated in built-up regions, while low-vulnerability areas are mainly located in surrounding forest and grassland ecosystems with higher ecological resilience. Over time, vulnerability gradually shifts outward from the urban core, with clear intensification along the urban fringe. The results indicate that ecological vulnerability is driven by the interaction of sensitivity, resilience, and pressure, while urban expansion plays a key role in intensifying ecological stress and reshaping spatial patterns. The study provides a framework for understanding ecological vulnerability dynamics in high-latitude resource-based grassland cities and supports zoning-based ecological management and land-use optimization. Full article

Hypertension is a severe global public health issue. Food-derived angiotensin-converting enzyme (ACE)-inhibitory peptides have shown great potential as safe and effective alternatives to synthetic antihypertensive drugs. Camel milk is rich in bioactive peptides. This study aimed to screen for ACE-inhibitory peptides from hydrolyzed camel casein, explore their inhibitory mechanisms and endothelial protective effects in vitro, and reveal their potential antihypertensive pathways using network pharmacology. This study screened three peptides with angiotensin-converting enzyme (ACE) inhibitory activity from enzymatically hydrolyzed camel casein components: MVPFLQPK, VPFLQPKVM, and QKWKFL, with IC₅₀ values of 277.1, 396.9, and 486.9 μmol/L, respectively. Enzyme inhibition kinetics analysis indicated that MVPFLQPK exhibited a non-competitive inhibition pattern, VPFLQPKVM exhibited a mixed inhibition pattern, and QKWKFL exhibited a competitive inhibition pattern. Molecular docking revealed that all three peptides formed hydrogen bond interactions with ACE, and QKWKFL and VPFLQPKVM directly bound to the enzyme’s active site to inhibit substrate catalysis. Molecular dynamics simulation further confirmed the high stability of the three peptide–ACE complexes, with binding free energies from −34.24 to −51.19 kcal/mol. The primary contributing forces include hydrogen bonds, van der Waals interactions, electrostatic forces, and nonpolar solvation effects. Network pharmacology analysis suggested that these peptides may exert synergistic antihypertensive effects by regulating multiple blood pressure-related pathways, including the renin–angiotensin system, renin secretion, and calcium signaling pathways, by acting on key targets such as ACE, REN, SRC, and MMP9. Cell experiments demonstrated that all three peptides exhibited no cytotoxicity in the Ang II-induced HUVEC injury model, significantly promoted NO release, inhibited ET-1 secretion, and possessed endothelial protective potential. This study investigated the in vitro ACE-inhibitory mechanism of peptides derived from camel milk and their potential role in blood pressure regulation, providing experimental evidence for subsequent in vivo activity validation and the development of functional camel milk protein products. Full article

This review aimed to evaluate the effectiveness and feasibility of non-pharmacological interventions to reduce anxiety and agitation and improve observable wellbeing and patient engagement for people with dementia in acute hospital environments. The global increase in dementia has resulted in a substantial number of acute hospital beds occupied by people with dementia. Hospitalisation can exacerbate behavioural and psychosocial symptoms of dementia (BPSD) including anxiety and agitation, which negatively affects patient experience, safety and care. Clinical guidance recommends non-pharmacological interventions as a first-line tactic to manage BPSD. However, evidence for the effectiveness and feasibility of these interventions remains fragmented in such pressured environments. A systematic search of seven databases was conducted for studies published in the last ten years (2015–25), following the PRISMA guidelines. Fourteen studies met the eligibility criteria and included a total of 749 people with dementia. Studies used mixed interventions; music, music therapy and person-centred care highly featured and most studies reported reductions in observable BPSD during or immediately after interventions. Secondary benefits included wellbeing, reduced psychotropic medicine use, length of hospitalisation and high staff and patient acceptability. There was limited evidence for sustained effects beyond intervention. This review supports the feasibility and effectiveness of non-pharmacological interventions in acute hospitals to support dementia-inclusive, person-centred care. Full article

Stock market investors and traders operate in high-pressure environments marked by volatility, uncertainty, financial risk, and intense performance demands. These conditions lead to substantial psychological distress, increasing vulnerability to psychiatric disorders and suicidal behavior. Key psychological risk factors in this population include acute financial loss, chronic stress, impulsivity, perfectionism, and identity fusion with professional performance. Evidence from behavioral psychology and clinical psychiatry indicates elevated rates of mood disorders, anxiety, and burnout in trading environments. Resilience—including emotional regulation, effective stress-coping mechanisms, strong social support, and cognitive flexibility—emerges as a critical protective factor that mitigates suicide risk and promotes adaptive functioning. Strengthening psychological resilience and implementing evidence-based mental-health strategies may help reduce suicide risk and support overall well-being. The medico-legal dimensions of this issue encompass duty of care within high-stress financial workplaces, clinical obligations related to suicide risk assessment and documentation, confidentiality and safety considerations, and questions of foreseeability of suicide in cases involving severe or catastrophic financial loss. Despite growing awareness of mental health challenges in financial professions, the intersection of suicide risk, resilience, and medico-legal responsibilities in this population remains underexplored. Further research is needed to refine assessment frameworks and develop targeted suicide prevention interventions for this at-risk group. Full article

The synergistic deformation and energy dissipation of backfill–surrounding rock composite structures under impact loading remain poorly understood, despite the frequent exposure of deep mine backfilled stopes to dynamic disturbances such as blasting and seismicity. In this study, Split Hopkinson Pressure Bar (SHPB) tests were conducted at a fixed impact pressure of 0.2 MPa on single-material specimens and bonded backfill–rock composite cylinders, with loading applied from both the backfill end and the surrounding rock end. Single backfill specimens exhibited dominant reflected energy (~90%) and low crushing energy consumption (<20%), whereas composite specimens displayed characteristic “double-peak” or “flat-peak” stress–strain signatures with peak strengths exceeding that of standalone backfill. When loading was directed from the high-strength surrounding rock into the backfill, the reflected energy ratio decreased to 60–80% and crushing energy consumption increased to 20–30%, demonstrating a loading-direction-dependent energy dissipation mechanism. These results provide a quantitative reference for optimizing blast sequence design in backfilled stopes. Full article

The COVID-19 pandemic placed unprecedented pressure on diagnostic services worldwide. The first cases of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the UK were confirmed on 31 January 2020, prompting National Health Service (NHS) laboratories to scale diagnostic procedures. The demand for testing rapidly exceeded historical norms for respiratory virus diagnostics, necessitating substantial government investment in consumables, assay development, and workforce expansion. This review presents a retrospective evaluation of SARS-CoV-2 diagnostic platforms deployed within the Norfolk and Norwich University Hospital (NNUH) trust and compares them with those implemented by other regional laboratories during the pandemic. It examines the molecular mechanisms, performance, scalability, and specificity of the multiple molecular testing approaches to optimise workflow based on the evolving technology. The integration of complementary platforms through a stratified testing strategy enabled high-throughput population screening while preserving diagnostic resolution for complex respiratory cases, substantially improving laboratory efficiency and resilience. The emerging diagnostic methodologies, RT-LAMP and CRISPR-based assays, are described, and we discuss their potential roles in future outbreaks. We critically evaluate the overall preparedness of UK health services for the COVID-19 pandemic and highlight key priorities for future pandemic preparedness at both local and national levels. Full article