Search Results (3,076)

Structural analysis using X-rays and electron beams has long provided the average arrangement of atoms and molecules—that is, “structural information”—with high precision. By contrast, static measurements cannot directly yield dynamic information on how a material changes over time; instead, information on motion is convolved into a single numerical value such as the B-factor (atomic displacement parameter). Taking this limitation as its starting point, this review surveys the recent trend of introducing a time axis into measurements to observe material dynamics directly. First, we outline the technological foundations that have made the transition from static to time-resolved measurement possible. It rests on the dramatic shortening of exposure times, enabled by the increased brilliance of X-ray and electron sources and by advances in detection technology such as direct photon-counting detectors. Next, we survey dynamic measurement techniques, including time-resolved X-ray crystallography, coherent X-ray scattering, neutron scattering, and time-resolved electron microscopy. We also point out the essential limitation that most of them still return ensemble or volume averages. Building on this, we systematically describe diffracted X-ray tracking (DXT), diffracted X-ray blinking (DXB), small-angle X-ray blinking (SAXB), transmitted X-ray blinking (TXB), and electron-beam molecular dynamics (EBMD), which use gold nanocrystals and gold nanoparticles as motion probes. We distinguish throughout between methods that follow individual objects—DXT and EBMD, which yield trajectories of single labeled molecules or single particles—and methods that analyze intensity fluctuations arising from many contributors within one pixel or illuminated volume—DXB, SAXB and TXB. The latter are not single-molecule measurements; rather, they replace a global ensemble average by a spatially localized statistical one, retaining local heterogeneity that a bulk measurement would average away. Finally, we discuss the implementation and prospects of the large-volume data analysis—principal component analysis, Bayesian inference, machine learning, and autonomous measurement—needed to handle the explosively increasing amount of information that the time axis introduces. We close with the outlook that time-resolved measurement incorporating AI and big-data analysis will become established as a new measurement platform that complements and extends conventional static structural analysis. Full article

Ti-6Al-4V titanium alloy is extensively employed in deep-sea structural applications owing to its excellent corrosion resistance, while its extra-low-interstitial (ELI) variant provides higher fracture toughness and is commonly presumed to exhibit even better stress corrosion cracking (SCC) resistance. In this work, displacement-rate-dependent fracture toughness (K_Q) measurements and failure analysis were performed for compact tension specimens machined from an engineering Ti-6Al-4V ELI plate with different orientations, tested in air and 3.5 wt.% NaCl solution over displacement rates of 0.0012–1.2 mm/min. In air, K_Q exhibits a pronounced loading-rate dependence, decreasing by more than 20% at low displacement rates relative to maximum rate, accompanied by quasi-cleavage features on the fracture surfaces indicative of hydrogen-assisted damage, likely arising from environmental or processing-related hydrogen uptake. In 3.5 wt.% NaCl solution, the minimum K_Q within the low-rate regime (0.0012–0.12 mm/min) is 58 MPa·m^0.5, comparable to values reported for conventional Ti-6Al-4V under similar conditions. The pronounced rate dependence and transition toward cleavage-like fracture reveal a strong coupling between loading kinetics and environmental degradation. This work demonstrates that enhanced intrinsic toughness does not necessarily translate into superior SCC resistance and establishes loading rate as a critical factor governing the environmental fracture of Ti-6Al-4V ELI under marine conditions. Full article

Surface roughening is a common defect in plastic deformation processing, directly affecting product surface quality and service performance. This study investigates the mechanisms of surface roughness evolution during plastic deformation by considering both intrinsic and extrinsic factors. A macro–meso-scale modelling framework is developed by coupling crystal plasticity finite element modelling, fluid–solid interaction modelling, and macro–meso boundary conditions. The crystal plasticity model incorporates a constitutive model based on crystal plasticity theory, a Voronoi-based geometric model, and a real rough-surface topography model to capture non-uniform grain-scale plastic deformation. Fluid–solid interaction modelling is introduced to analyze the influence of liquid lubricant on the deforming solid material. Boundary interpolation and continuous displacement theories are then used to transfer macro-scale boundary constraints to the meso scale. The proposed framework is numerically implemented and applied to the aluminum alloy tube drawing process. The effects of intrinsic factors, including grain size, grain orientation, and initial surface roughness, and extrinsic factors, including deformation path, strain rate, and lubrication condition, are systematically examined. From a practical point of view, effective strategies to improve surface quality are by reducing grain size, lowering initial surface roughness, decreasing the strain rate and using low-viscosity lubricants. Full article

This exploratory descriptive-correlational study analyses the perceptions of 257 adult students (doctoral, master’s, and teachers) at DPPD, USV Iași, during the 2025–2026 academic year regarding hybrid education, teaching quality, and environmental sustainability. Using a structured Likert-scale questionnaire, the analysis indicates good-to-excellent internal consistency, with Cronbach’s alpha values ranging between 0.886 and 0.901, and a high overall global average score of 4.64. The findings reveal strong support for the hybrid model. Perceived teaching quality received the highest subscale rating (M = 4.80), closely followed by the perceived ecological impact (M = 4.65). The analysis indicates strong Pearson correlations, specifically between the hybrid learning experience and perceived teaching quality (r = 0.818), as well as between the perceived ecological impact and pro-sustainability attitudes (r = 0.809). Regarding academic mobility, the estimate indicates 81,283 km of avoided commuting travel and approximately 12,295 kg of avoided commuting-related CO₂ emissions, based on self-reported distance, means of transport, and number of physical attendances replaced by online activities. These findings suggest that hybrid learning may represent a relevant managerial option for university sustainability policies. The model appears well suited to postgraduate programmes addressed to employed adults, although the ecological benefits should be read as partial and do not displace perceived teaching quality as the central factor. Full article

Hybrid cross-laminated timber combining plantation Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) with oriented strand board (OSB) is resource-efficient, but its bond line may govern delamination. Double cantilever beam (DCB) specimens bonded with one-component polyurethane were tested at four initial crack lengths (a₀ = 40–100 mm), comparing untreated bond lines with bond lines pretreated by sandblasting followed by hydroxymethylated resorcinol (HMR). The arms differed in bending stiffness by a factor of about 3.7, so the specimen was an asymmetric bi-material DCB, and the reported values were apparent, predominantly Mode I quantities. Pretreatment raised the critical load by 17%–24% and the apparent initiation toughness by 18%–35%. A bilinear cohesive-zone model with one parameter set per surface condition reproduced all eight calibration groups to within 5% in critical load and load-point displacement; the calibrated cohesive energies (402 and 594 N/m) differed from the apparent toughness at a₀ = 100 mm by −9.6% and +12.9%. Apparent toughness fell with crack length, but the measured compliances do not follow the cubic scaling expected of a DCB, so this trend is unexplained. The calibrated parameters describe the responses measured here; their transfer to other geometries remains to be verified. Full article

This paper investigates the degradation law and calculation method for the load-carrying capacity of steel–concrete composite girders under fire exposure based on numerical analysis and mathematical statistics. A finite element model of simply supported box-section steel–concrete composite girders is established using ABAQUS, which is validated against existing scaled test data in terms of temperature field distribution, load-carrying capacity, and mid-span displacement. On this basis, the parametric effects of concrete slab thickness, steel web height, steel plate thickness, and concrete strength on the load-carrying capacity of the girders are systematically analyzed. The results indicate that concrete slab thickness, steel web height, and steel plate thickness exert significant influences on the structural bearing capacity, whereas concrete strength has a negligible effect. Specifically, the load-carrying capacity under fire exposure is substantially improved with the increase in concrete slab thickness, steel web height, and steel plate thickness. Furthermore, a simplified calculation formula for the capacity of box-section steel–concrete composite girders under fire exposure is developed via multiple linear regression analysis, incorporating the three dominant influencing factors of concrete slab thickness, steel web height and steel plate thickness. The proposed formula exhibits satisfactory calculation accuracy and can provide a reliable reference for the fire resistance design and repair decision-making of steel–concrete composite girders. Full article

Accurate localization of bounding boxes is a prerequisite for enabling vision-driven precision agriculture pipelines, as downstream tasks such as morphological feature extraction, growth monitoring, and digital-twin synchronization depend directly on the geometric quality of the detected boxes. Distance-IoU (DIoU) and Complete-IoU (CIoU) improve upon simple overlap-based objectives by incorporating a normalized center-distance term into the regression loss, along with the overlap and, for CIoU, an aspect-ratio penalty, but that term remains embedded in a single composite formulation with an implicit, non-adjustable weight. We propose a Directional Alignment Penalty (DAP), an auxiliary localization regularizer that introduces an independently weighted normalized center-displacement term into the bounding-box regression objective without modifying the detector architecture. The proposed DAP-YOLOv8 increased mAP@0.5:0.95 from 51.69% to 53.76% and mAP@0.5 from 80.03% to 80.36% while preserving precision and recall; repeated-seed experiments further showed that the improvement in fine-grained localization was consistent across random initializations on a purpose-built oyster-mushroom (Pleurotus ostreatus) dataset collected from a real-world smart greenhouse. Results show that explicitly modeling the center-distance factor as an independent and tunable component can improve fine-grained localization without sacrificing the computational efficiency of the base detector, thereby providing a lightweight plug-in extension for agricultural detection and digital-twin applications. Full article

A unified modeling framework is presented in this work to predict the free vibration and loss factor characteristics of damping sandwich rotational plates. The formulation starts from the first-order shear deformation theory, where the zigzag hypothesis and interlayer displacement continuity are combined to couple the displacement fields of the individual plies. An artificial spring scheme is adopted to enforce the layer–layer compatibility and the external boundary restraints, which leads to a Lagrangian functional composed of the kinetic energy, the strain energy, and the potential energies contributed by the boundary and coupling springs. The displacement unknowns are discretized with Chebyshev polynomials of the first kind, and the natural frequencies and damping loss factors are extracted by solving the resulting eigenvalue problem with the Rayleigh–Ritz method. Convergence tests are conducted, and the reliability of the model is validated against finite element results. Finally, a series of numerical examples is presented to systematically investigate the effects of key model parameters on the vibration characteristics of the structure. The results indicate that increasing the thicknesses of the inner and outer layers of the damping sandwich rotational plate structure can significantly raise the natural frequencies. Increasing the inner diameter helps to reduce the area of the low-frequency region, where the difference between the two sides exceeds 40 Hz, caused by the close thicknesses of the inner and outer layers. When only the outer boundary is clamped, the natural frequencies of the annular plate are more than twice those of the solid rotational plate, although the solid rotational plate yields a larger loss factor. When only the outer circular edge is fixed, increasing the total thickness of the structure can effectively raise the natural frequencies, with a maximum increase exceeding 110 Hz, while the loss factor decreases significantly. Full article

Background/Objectives: This study aimed to compare the incidence, extent, and time to diagnosis of osteonecrosis of the femoral head (ONFH) between Femoral Neck System (FNS) and multiple cannulated screw (CS) fixation in patients with femoral neck fractures (FNFs) at a minimum follow-up of 24 months, as well as to identify factors associated with ONFH after FNS fixation. Methods: A retrospective cohort study was conducted at a single university hospital involving patients aged ≥18 years with isolated FNFs treated by closed reduction and internal fixation using either FNS or multiple CS. Reduction quality, fracture union, incidence and extent of ONFH (measured by Kerboul angle), and revision surgery due to ONFH or other causes were assessed as outcome measures. Logistic regression analyses were conducted to identify factors associated with ONFH after FNS fixation. Results: Eighty-seven patients were included, comprising 48 in the FNS group and 39 in the CS group. No significant differences were found between the groups in reduction quality, union rate, or time to union (p > 0.05 for all). The incidence of ONFH did not differ significantly between the FNS and CS groups (p = 0.314). However, the FNS group showed a significantly greater extent of ONFH (p = 0.031) and longer mean time to ONFH diagnosis (p = 0.001). No significant differences were observed in revision surgery rates due to ONFH (p = 1.000) or other causes (p = 0.624). Multivariate analysis identified fracture displacement (Garden classification stages III and IV) and poor reduction quality (“Broken S” by Lowell’s criteria) as significant predictors of ONFH after FNS fixation. Conclusions: ONFH following FNS fixation tended to exhibit a larger necrotic area and a delayed radiographic onset compared to CS fixation; however, the overall incidence and revision rates were comparable between implants. These differences may be due to initial fracture displacement and baseline severity, rather than the FNS implant itself. In the FNS group, the mean time to radiographic diagnosis of ONFH was 13.1 months, and initial fracture displacement and reduction quality were identified as risk factors for the development of ONFH following FNS fixation. Therefore, long-term and vigilant follow-up is essential after FNS fixation, particularly in patients with displaced fractures. Achieving optimal reduction quality and anatomical femoral neck alignment remains paramount to mitigating the risk of ONFH after FNS fixation. Full article

Earthquake-induced fracturing and microcrack development in subsurface strata are widely recognized as important processes influencing seepage and the hydrological behaviour of surface water bodies, particularly in tectonically active mountainous terrains. However, the hydrogeological response to repeated low-magnitude (<4) seismic events remains poorly understood. This study presents an integrated geoelectrical and remote sensing investigation of the Nagi Lake region in the Sikkim Himalaya, India, based on Vertical Electrical Sounding (VES) surveys conducted in May 2022 and March 2026, following a seismic sequence of 74 low-magnitude earthquakes recorded during February 2026. Comparative analysis of four VES profiles (VES1–VES4), supported by validatory factor analysis, reveals spatially heterogeneous changes in subsurface electrical characteristics between the two survey periods. VES1, VES2, and VES3 indicate reduced signatures of pre-existing microcracks that are consistent with sediment densification and partial sealing, whereas VES4 suggests localized development or persistence of microfractures. Because the surveys span approximately four years, these changes likely reflect the combined influence of long-term hydrogeological, environmental, and geomorphic processes, with the February 2026 seismic sequence representing one potential contributing factor rather than the sole driver. To further evaluate ground deformation, Sentinel-1A Synthetic Aperture Radar (SAR) data acquired between January 2019 and March 2026 were analysed using Persistent Scatterer Interferometric SAR (PS-InSAR). The results indicate cumulative Line-of-Sight (LOS) displacements ranging from −17.9 cm (movement away from the satellite) to +3.5 cm (movement toward the satellite) in the vicinity of Nagi Lake, reflecting localized surface deformation with millimetre-scale precision. These observations provide complementary evidence of ongoing subsurface adjustment that may promote sediment compaction and microcrack modification. Overall, the study demonstrates measurable temporal changes in the subsurface structure of the Nagi Lake area and suggests that repeated low-magnitude seismicity may contribute to subsurface restructuring alongside other environmental processes. The findings highlight the value of integrating geophysical monitoring and satellite-based deformation analysis for understanding groundwater–surface water interactions and supporting the sustainable management of vulnerable Himalayan water bodies. Full article

Carbon nanotubes (CNTs) are widely used as nanoscale reinforcements in polymer composites because of their high stiffness, high aspect ratio, and ability to enhance interfacial stress transfer. In woven Kevlar/epoxy composites, however, the mechanical benefit of CNT addition depends not only on nanotube presence, but also on whether the fabric Fiber orientation enables the CNT-modified interface to participate effectively in the dominant load path. In this study, woven Kevlar/epoxy composites with and without 4 wt.% multi-walled carbon nanotube (MWCNT) treatment were investigated under three displacement rates, namely 1, 10, and 100 mm/s, for two specimen orientations relative to the woven yarn directions: 0°/90° and ±45°. The 0°/90° Fiber orientation represents a tension-dominant load path, whereas the ±45° Fiber orientation promotes yarn rotation and matrix-shear-dominant deformation. The experimental results show that CNT treatment produces a clear increase in elastic modulus in the 0°/90° composites, with an improvement of approximately 40–50% at the lowest loading rate and continued enhancement at higher rates. In contrast, only limited gains are observed in the ±45° composites. The calculated CNT engagement index reached 0.8667 in the 0°/90° Fiber orientation but remained low or negative in some ±45° loading conditions, indicating that the effectiveness of CNT reinforcement depends strongly on Fiber orientation relative to the woven yarn directions. To interpret this behavior in a design-oriented manner, three Fiber orientation-sensitive comparison parameters are introduced: the CNT engagement index, the Fiber orientation sensitivity factor, and the rate amplification factor. These descriptors distinguish absolute stiffness from actual reinforcement utilization and indicate that modulus improvements depend on specimen orientation relative to the woven yarn directions. This study indicates that fabric Fiber orientation governs whether the CNT-modified interface is effectively mobilized or largely bypassed. This provides a useful framework for selectively deploying CNT reinforcement in woven protective composite systems and for rethinking nanotube reinforcement as a load-path-dependent design feature rather than a universally effective additive. Full article

Higher education institutions are increasingly expected to reduce greenhouse gas emissions while maintaining reliable educational, laboratory, and administrative operations. This challenge is particularly relevant in transition economies, where university campuses often depend on fossil-fuel-based electricity systems, natural-gas heating, and aging infrastructure. This study presents a campus-scale decarbonization assessment for the Tashkent Institute of Chemical Technology in Uzbekistan. The quantified inventory covered Scope 1 emissions from natural-gas combustion and Scope 2 emissions from purchased electricity. Paper use, digital services, behavioural measures, and campus greening were assessed as supplementary institutional indicators and were excluded from the quantified total because consistent pre- and post-intervention activity data were unavailable. The assessment combined institutional utility records for 2023–2025 with information on renewable-energy deployment, heating modernization, digital transformation, sustainability awareness, and campus greening. A 300 kW solar photovoltaic system comprising 666 modules was commissioned in May 2023, with a documented annualized generation potential of approximately 520,000 kWh. Purchased grid electricity amounted to 711,402, 745,947, and 749,060 kWh in 2023, 2024, and 2025, respectively, while annual natural-gas consumption was 144,775, 161,200, and 142,031 m³. Using a conservative standard-based net calorific value of 31.8 MJ/m³ together with IPCC stationary-combustion factors, annual Scope 1 and Scope 2 emissions were estimated at 637.53, 685.29, and 652.65 tCO₂-eq, respectively. The 2025 total was 4.76% below the 2024 value but 2.37% above the 2023 value. The annualized PV technical potential corresponds to a theoretical maximum Scope 2 displacement of 276.64 tCO₂-eq/year under 100% self-consumption. This value does not represent measured generation or a realized emission reduction and was not included in the quantified inventory. Digitalization, behavioural engagement, and greening were evaluated as complementary measures rather than assigned separate emission-reduction credits. The study provides a transparent and regionally relevant framework for universities in transition economies seeking to strengthen campus carbon management under incomplete data conditions. Full article

Marine concrete structures are subjected to multiple aggressive ions that react with hydration products, driving dynamic phase evolution and altering ion transport pathways. This study develops a multi-scale lattice diffusion–reaction coupled framework grounded in a microstructural evolution model, incorporating a simplified analytical correction for the electrical double layer (EDL) effect. Validation against Poisson–Boltzmann numerical solutions across a pore size range of 1.5–50 nm confirms that the mean relative errors for monovalent, divalent, and trivalent ions remain within 10%. The phase evolution of cement paste under single-ion attack was simulated, and its impact on ion transport performance under multi-ion coupled ingress was systematically investigated. Under multi-ion attack, solid phases exhibit a highly ordered spatial zonation. Chloride ions completely displace monosulfate, forming a Friedel’s salt-enriched zone. Meanwhile, directly penetrating external sulfate generates a pronounced surface ettringite peak, while sulfate released from monosulfate decomposition in the Friedel’s salt zone induces secondary ettringite precipitation deeper within the material, producing a characteristic double-step ettringite distribution. A cracking criterion based on the critical capillary pore filling fraction captures the transition from pore filling to microcracking, yielding a three-zone profile for the relative diffusion coefficient. At 500 days of exposure, crystallization-induced microcracking triggers a more than 7-fold increase in surface relative diffusivity ($w/c$ = 0.35). Furthermore, at 250 days, once cracking initiates, low water-to-cement ratio ($w/c$ = 0.3) matrices display a higher relative diffusivity amplification factor of approximately 9, compared to approximately 6 for high water-to-cement ratio ($w/c$ = 0.4) matrices. The established framework provides a quantitative tool for assessing the durability of concrete structures under complex chemical attack environments. Full article

Carbon dioxide water-alternating-gas (CO₂-WAG) flooding simultaneously enables carbon emission mitigation, improved oil displacement efficiency, and expanded gas sweep coverage. Nevertheless, the field performance of this technology remains significantly constrained by gravity override effects, especially in ultra-thick oil reservoirs. In this work, a synthetic heterogeneous dipping mechanistic reservoir model is constructed. Using a quantitative metric for gravity override index in WAG processes, the variation patterns of gravity override under various operational factors are systematically analyzed. Furthermore, the eXtreme Gradient Boosting (XGBoost) machine learning algorithm is employed to conduct feature importance analysis of the controlling factors, identifying parameters with the most substantial impacts. The results indicate that well spacing, oil production rate, WAG injection strategy, and WAG slug duration all exert pronounced effects on both gravity override index and oil recovery factor. Gravity override is confirmed as the dominant factor governing the production performance of WAG flooding in ultra-thick reservoirs. In addition, an optimal combination of operational parameters exists that counterbalances the adverse effects of gravitational and viscous forces, thereby maximizing gas sweep efficiency, delaying gas breakthrough, and enhancing oil recovery. This study provides valuable insights and technical guidance for gas channeling mitigation, vertical gas sweep improvement, and efficient development of analogous ultra-thick reservoirs. Full article

Background/Objectives: Breast cancer-related upper-limb lymphedema (BCRL) can impair arm function and quality of life, while objective measures may not fully reflect patient-perceived burden. This study examined associations of objective severity, pain intensity, and shoulder range-of-motion (ROM) limitation with disability and lymphedema-specific quality of life in women with BCRL. Methods: This cross-sectional analysis included 110 women with clinically diagnosed BCRL. Objective severity was assessed using International Society of Lymphology stage, circumferential measurements, and water displacement volumetry. Pain was evaluated with a visual analog scale. Disability was assessed using the Quick Disabilities of the Arm, Shoulder and Hand questionnaire (QuickDASH), and lymphedema-specific quality of life using the Quality of Life Measure for Limb Lymphedema-Arm (LYMQOL-Arm). Analyses included nonparametric comparisons, Spearman correlations, and exploratory multivariable regression. Results: Higher lymphedema stage was associated with greater circumferential and volumetric differences and worse QuickDASH, LYMQOL function, and LYMQOL appearance scores. Objective severity measures correlated with QuickDASH, LYMQOL function, and LYMQOL appearance, but not with pain or LYMQOL symptoms. Shoulder ROM limitation was associated with higher pain, worse QuickDASH, higher LYMQOL function, appearance, and symptom scores, and lower global quality of life. In regression analyses, pain intensity, volumetric difference, and shoulder ROM limitation remained associated with QuickDASH, whereas pain intensity was the main factor associated with global quality of life. Conclusions: Objective severity measures mainly reflected anatomical, functional, and appearance-related burden but did not fully capture pain, symptoms, or global quality of life. Multidimensional assessment combining limb measurements, pain evaluation, shoulder mobility assessment, and patient-reported outcomes may support a more comprehensive clinical evaluation of women with BCRL. Full article