Search Results (774)

Background/Objectives: Accurate determination of active pharmaceutical ingredient (API) particle size within dry powder inhaler (DPI) formulations is essential for ensuring effective pulmonary delivery but remains analytically challenging due to low API content and micronized particle size. Methods: In this study, scanning electron microscopy (SEM) coupled with energy-dispersive X-ray microanalysis (EDX) was used to directly identify and calculate the API particle size within several different commercial DPI products fit for purpose under regulatory constraints. The method exploits unique elemental markers inherent to each API, enabling reliable discrimination from excipients without prior sample modification or API extraction. Results: Large-area SEM–EDX mapping was used to localize API particles, followed by high-magnification imaging and confirmatory spot microanalysis. Particle sizes were manually measured for at least 50 API particles per formulation using image analysis software, and particle size distribution parameters were calculated from equivalent spherical diameters. Conclusions: The methodology was successfully applied to Spiriva^®, Anoro^® Ellipta, and Relvar^® Ellipta inhalation powders, revealing micronized APIs with distinct morphological features and verifying systematic application across products. Cross-validation against laser diffraction measurements of pure APIs demonstrated statistical equivalence, confirming the robustness and analytical utility of the proposed method for particle size assessment in DPI formulations. Full article

Porous medium combustion technology, renowned for high efficiency and low emissions, is widely applied in industrial and heating fields. This study numerically investigates pore-scale heat transfer, flame morphology, reaction rate distribution during standing combustion in a one-layer randomly packed bed, and flow parameter effects on flame behavior. A 3D randomly packed model (tube-to-particle diameter ratio D/d = 10) is developed using the discrete element method (DEM) and coupled with computational fluid dynamics (CFD) to resolve pore-scale transport processes. Results show that exothermic combustion converts internal energy to kinetic energy, significantly accelerating pore-scale flow velocity in the combustion zone. Increasing the equivalence ratio enhances flame stability, elevating solid–fluid temperatures by 200 K and expanding the combustion zone volume by 20%. The pore Reynolds number promotes inertial mixing and heat redistribution, limiting the solid–fluid temperature difference to 10 K. Local flames evolve from dispersed to wrinkled and undulating. These findings elucidate pore-scale combustion dynamics and guide packed-bed reactor design and optimization. Full article

This study proposes a principal component analysis-based convolutional neural network (PC-CNN) to correct atmospheric turbulence-induced aberrations. Unlike traditional Zernike polynomials (ZPs)-based methods (ZP-CNN), PC-CNN avoids mode aliasing and cross-coupling via the strict orthogonality of principal components (PCs). A coefficient magnification strategy is incorporated to further enhance efficacy, maximally preserving the intrinsic physical information within the PCs coefficients. A series of systematic experiments was conducted under conditions from weak to strong turbulence, characterized by $D/r_0$ from 1 to 25, where $D$ is the pupil diameter and $r_0$ is the atmospheric coherence length. Quantitative results show PC-CNN achieves a lower mean relative error (MRE) in coefficient prediction than ZP-CNN under equivalent conditions. It also yields a higher Strehl ratio, reduced speckles, and enhanced spot clarity while requiring fewer basis terms, demonstrating high stability and robustness in strong turbulence. These findings emphasize that basis function orthogonality and physically informed preprocessing are critical design principles for deep-learning-based wavefront sensor-less adaptive optics (AO), establishing a robust foundation for real-time intelligent AO systems in astronomy and free-space optical communications. Full article

Carbon nanotube (CNT)-based hydrogels continue to present a persistent challenge of material comparability, as systems that appear equivalent frequently generate different mechanical, electrical, and biological responses. Although experimental variability is frequently cited as the primary explanation, many discrepancies arise from comparing systems whose nanotubes differ structurally in ways that are rarely documented. Diameter distribution, defect density, residual catalyst content, and surface chemistry directly influence CNT dispersion, network integration, and interactions in hydrated polymer matrices. When these parameters are insufficiently reported, formulations that appear comparable may represent materially distinct systems. In this review, the CNT–hydrogel literature is reconsidered from the perspective of material comparability. Rather than focusing only on whether reported results agree across studies, this review evaluates whether sufficient structural and processing information is available to determine if the systems being compared are materially equivalent. Selected publications were analyzed using a reporting-based descriptor framework encompassing nanotube origin, structural characterization, dispersion, microstructure, transport behavior, and biological relationships. A consistent pattern emerges: reproducibility becomes more interpretable when nanotube identity and processing history are documented with sufficient resolution. This enables meaningful cross-study comparison without requiring strict protocol standardization. Full article

This study systematically investigated the bearing capacity and failure mechanisms of ultra-high-performance concrete (UHPC) pipe jacking structures using three-edge bearing tests and numerical simulations. Full-scale double-layer reinforced pipes had an inner diameter of 2.5 m and wall thicknesses of 180 mm (P1) and 200 mm (P2). The tests showed that the failure process can be divided into four stages: elastic deformation, crack propagation, reinforcement yielding, and ultimate failure. Increasing the wall thickness significantly improved performance: P2 had a cracking load 52.73% higher and an ultimate bearing capacity 5.7% higher than P1, with better deformation resistance and crack control. A theoretical model considering the plastic hinge mechanism at the pipe crown was developed, treating the three-edge load as an equivalent distributed plate load. The calculated results agreed well with experimental measurements. An ABAQUS finite element model successfully reproduced the full mechanical response from initial loading to failure. Parametric analysis indicated optimal performance at a hoop reinforcement ratio of approximately 1.4%. Even at 0.6%, the ultimate bearing capacity reached 367 kN/m, meeting current design code requirements. This study is novel in conducting full-scale UHPC pipe jacking tests, proposing a theoretical model accounting for crown plastic hinges, and establishing a finite element method that reproduces the entire failure process. Optimizing wall thickness and hoop reinforcement can enhance structural safety and durability, providing guidance for the design and engineering of pipe jacking structures. Full article

Background: Lipomas are common benign subcutaneous neoplasms treated surgically for cosmetic or symptomatic reasons. The minimal one-third incision and four-step (MOTIF) technique provides reliable excision with minimal scarring, but smaller proportional incisions remain unstudied. This study evaluates the minimal one-quarter incision and four-step (MOQIF) technique. Methods: Retrospective review of 82 patients undergoing MOQIF excision of histologically confirmed subcutaneous lipomas by a single surgeon from July 2024–December 2025 was done. Lipomas were stratified by maximum diameter: small-intermediate (<5 cm) and large (≥5 cm). MOQIF used a one-quarter incision of the lipoma’s long axis determined by preoperative ultrasound measurement and palpation with four steps: hydro dissection preserving superficial subcutaneous tissue, superficial dissection, staged deep dissection with selective cautery of fibrovascular septa, and intact mass delivery. Outcomes included excision length, postoperative complications, Vancouver Scar Scale (VSS) scores, recurrence, and subjective treatment satisfaction of patients. Results: Mean lipoma size was 6.8 ± 2.0 cm (75.6% ≥5 cm). All lipomas were completely excised through 1.69 ± 0.49 cm incisions (ratio 0.25). Complications were low: seroma 10.98% (16.7% vs. 9.4%, p = 0.404), hematoma 7.3% (11.1% vs. 6.3%, p = 0.608), with no infections, nerve injuries, or recurrences at a mean 8.9-month follow-up. VSS scores were equivalent between groups (0.83 vs. 1.06; p = 0.438) and overall patient satisfaction was high (3.54 ± 0.53 (2–4)). Conclusions: MOQIF achieves complete lipoma excision through one-quarter incisions with safety and cosmetic outcomes across lipoma sizes, demonstrating feasibility through standardized technique refinement and careful case selection. Full article

For deep-draft cylindrical platforms with a large annular column boot, the influence of the column boot diameter-to-height ratio (d/h) on motion performance remains unclear. This study investigates the effect of d/h on platform hydrodynamics while keeping the main body geometry, displacement, and draft unchanged. A hybrid numerical model validated against tests is adopted: STAR-CCM+ free-decay simulations identify equivalent linear damping, and ANSYS AQWA predicts hydrodynamic coefficients, response amplitude operators, and coupled time-domain responses under a 100-year survival sea state in the western South China Sea. Increasing d/h substantially increases heave added mass and added pitch moment of inertia, leading to longer natural periods and higher damping in heave and pitch. However, its effect on motion responses is non-monotonic and strongly response-dependent. As d/h increases, the responses are initially reduced markedly. The minimum surge and heave responses occur at d/h = 2.39 and 4.67, with reductions of about 34.0% and 87.2%, respectively, while the pitch response is already reduced by about 67.3% at d/h = 7.22. Further increases in d/h may weaken surge and heave mitigation while providing limited additional benefit for pitch. These findings provide qualitative understanding and quantitative guidance for response-oriented column boot design and optimization of similar platforms. Full article

Pulsating heat pipes (PHPs) are promising passive heat-transfer devices for compact thermal management; however, their performance is highly sensitive to channel geometry. In particular, the operating-condition-dependent influence of sinusoidal corrugation amplitude on the condenser side remains unclear, despite its importance for oscillation regulation and heat dissipation. This numerical study investigates a single-loop PHP with sinusoidally corrugated condensers (A = 0.25 and 0.5 mm) under heat fluxes of 5000–12,500 W/m² and filling ratios of 40–60%, using a uniform-diameter PHP as the baseline. The results show that the configuration with A = 0.25 mm exhibits better start-up performance, especially at low heat fluxes, whereas both corrugated configurations provide better thermal performance than the baseline. At a filling ratio of 50%, the thermal-resistance reductions for A = 0.25 and A = 0.5 mm are 14.5% and 9.2% at 5000 W/m² and 8.4% and 10.5% at 12,500 W/m², respectively. An operating-condition-dependent amplitude-matching relationship is identified: The smaller amplitude is more favorable for start-up under weak driving conditions, whereas the larger amplitude tends to provide lower thermal resistance and higher equivalent thermal conductivity under strong driving conditions. These findings provide useful guidance for condenser-geometry optimization in single-loop PHPs. Full article

Sustainable agricultural techniques can ensure food security around the world. Hydrogel based soilless culture is an ecological and efficient alternative compared to conventional agriculture. Here, a multi-component hydrogel (pectin, Kelcogel, and chitosan/Se hydrogel, PKCH) was prepared by synthesizing natural biomolecules to cultivate dandelion for stimulate dandelion growth and improve nutritional value. The germination percentage of dandelion on PKCH (88.89%), was significantly higher than that in traditional hydroponics and pure Kelcogel (p < 0.05). Compared with hydroponics, the long-term dandelion cultivation experiments demonstrated that the PKCH cultivation mode enhanced root vitality, further increasing the growth and yield of dandelions (shoot length: 18.36 ± 0.30 cm, root length: 9.28 ± 0.21 cm, main root diameter: 0.94 ± 0.02 cm). The hydrogel substrate was associated with improved nutrient solubilization and sustained release, which may be linked to the accumulation of low-molecular-weight organic acids in the rhizosphere. Exogenous Se was effectively assimilated and transported to the above-ground parts of dandelion, which stimulated the photosynthetic efficiency and nutritional accumulation of dandelion. The polysaccharide content of dandelion reached 69.40 ± 0.13% (expressed as glucose-equivalent total sugars), which demonstrated the potential antioxidant properties and medicinal value. Technical economic analysis revealed the cost-effectiveness of PKCH synthesis and application. This study enriches the application of hydrogels in dandelion cultivation and provides an alternative approach for cultivating dandelion in soilless environments and medicinal crop production techniques. Full article

This study addresses the challenge of consistently transferring atomistic parameters of the C–C bond into phenomenological material characteristics within the framework of continuum mechanics. Particular attention is given to determining the effective transverse diameter of the covalent C–C bond in carbon nanostructures. The dependence of this diameter on Poisson’s ratio ν is examined, and the influence of the interatomic stiffness constants ${\mathrm{k}}_{\mathrm{r}},{\mathrm{k}}_{\mathsf{\theta }}\mathrm{and}{\mathrm{k}}_{\tau }$ is systematically analyzed. Classical representative-volume models of the C–C bond based on the Euler–Bernoulli beam hypothesis violate thermodynamic stability conditions and lead to nonphysical Poisson’s ratio values exceeding 0.5, due to the neglect of shear deformation effects. To overcome this limitation, an approach based on Timoshenko beam theory is proposed, accounting for both bending and shear deformations. This approach enables estimation of energetically equivalent states between the phenomenological representative volume and the corresponding atomistic C–C bond model. As a result, a sixth-order algebraic equation is derived linking the effective bond diameter, the Poisson’s ratio, and the molecular mechanics force constants. Analysis of this equation reveals a narrow range of effective bond diameters and Poisson’s ratios for which thermodynamic stability conditions are satisfied. Within this range, physically consistent macroscopic material parameters can be directly expressed in terms of atomistic force constants. Full article

Al₂O₃-Cu ceramic-metal composites containing 2.5 vol.% of a metallic phase were fabricated using the Pulse Plasma Sintering (PPS) method in order to evaluate the influence of sintering temperature on densification, microstructure, and mechanical performance. Consolidation was carried out at 1200 °C, 1250 °C, 1300 °C, and 1400 °C under uniaxial pressure with a short sintering time of 3 min. Regardless of the processing temperature, all composites exhibited very high relative densities exceeding 99% of the theoretical value, indicating the high efficiency of PPS in densifying Al₂O₃-Cu systems while suppressing copper leakage. X-ray diffraction confirmed the presence of only two phases, Al₂O₃ and Cu, with no secondary reaction products. Microstructural observations revealed irregular copper particles and areas of dispersed metallic phase, whose proportion decreased with increasing sintering temperature due to accelerated matrix densification and copper immobilization. Grain growth in the alumina matrix was strongly temperature-dependent, with the average equivalent grain diameter increasing from 0.49 µm at 1200 °C to 2.35 µm at 1400 °C. Hardness decreased from 19.5 ± 2.8 GPa to 12.2 ± 1.6 GPa with increasing temperature, whereas fracture toughness reached a maximum of 5.42 ± 0.65 MPa·m0.5 at 1400 °C. The highest strength under monotonic compression conditions was obtained for samples sintered at 1300 °C, indicating an optimal balance between densification and microstructural coarsening. These results demonstrate that PPS is an effective method for producing dense Al₂O₃-Cu composites with tailored microstructure and mechanical properties. Full article

To address the poor cutting stability and deterioration of hole quality caused by the inherent trade-off between chip evacuation performance and drill-body stiffness in U-drilling, a multi-objective optimization framework was established. The design variables were the core thicknesses ${\mathrm{L}}_1$ and ${\mathrm{L}}_2$ of the inner and outer chip flutes, the inner and outer offset angles ${\mathrm{\theta }}_1$ and ${\mathrm{\theta }}_2$, and the inner and outer helix angles ${\mathrm{\beta }}_1$ and ${\mathrm{\beta }}_2$. The objectives were to maximize the chip evacuation force and minimize the drill-body strain (which serves as an equivalent indicator of maximizing drill-body stiffness). The chip evacuation force was rapidly evaluated using a mechanistic chip evacuation force model derived from mechanism-based analysis. The drill-body strain was efficiently predicted using a GA–BP neural-network surrogate model. An NSGA-II algorithm combined with the entropy-weighted TOPSIS method was employed to solve the optimization problem, yielding the optimal parameter combination for the U-drill chip-flute geometry. The results show that drilling experiments on 42CrMo under the optimal structural parameter combination reduced the cutting forces in the $x$, $y$, and $z$ directions by approximately 11.2%, 13.1%, and 11.8%, respectively. The root-mean-square acceleration in the $x$ and $y$-directions decreased by about 17.3% and 22.9%, respectively. These improvements effectively enhanced the hole-wall surface roughness and hole diameter accuracy, and further improved chip evacuation smoothness and cutting stability of the U-drill. Full article

Reinforcing steel bars in coastal regions are frequently exposed to chloride-rich environments before the concrete placement, yet the mechanical consequences of this pre-embedding exposure are rarely quantified. This study experimentally investigates the corrosion progression and mechanical degradation of ASTM A615 grade 60 reinforcing steel bars subjected to natural marine exposure and accelerated simulated chloride conditions using real Arabian seawater. Bare bars of 10 mm diameter were exposed to outdoor coastal conditions in Karachi and to an electrically accelerated seawater environment. A periodic evaluation was carried out up to 270 days, including visual inspection, mass loss, diameter reduction, tensile testing, and microstructural characterisation using scanning electron microscopy (SEM). Natural exposure produced gradual general corrosion, corresponding to ~0.5% annual cross-sectional loss and minor reductions in tensile strength within experimental variability. In contrast, simulated chloride exposure markedly accelerated deterioration, causing diameter losses approaching 1 mm and reductions in yield and ultimate strength of up to 20–25% within 60 days. Strength degradation trends closely followed section loss, indicating cross-sectional reduction as the dominant observed factor. SEM observations showed porous and cracked corrosion products with limited protective capacity. A performance-based time equivalence between natural and simulated exposure was derived from degradation trends while acknowledging possible mechanistic differences. Regression models relating exposure parameters to residual strength showed strong agreement with experimental data. The findings demonstrate that pre-placement marine exposure can introduce measurable steel degradation, underscoring the need to account for construction-stage corrosion in durability management of reinforced concrete in coastal regions. The findings highlight the critical impact of pre-embedding chloride exposure on reinforcing steel performance and emphasise the need to incorporate construction-stage corrosion effects into durability-based design and marine construction practices. Full article

To study the anchoring performance of a self-drilling anchor in sandy gravel strata, the influence of different anchoring lengths on the ultimate pull-out resistance of the self-drilling anchor was carried out through field tests, and the load-displacement curve was obtained. Based on this, combined with the indoor grouting test, an indoor orthogonal test scheme in line with the construction technology of the self-drilling anchor was designed, and the effects of different fine particle proportions, grouting pressures, and water-cement ratios on the pull-out peak, ultimate displacement, anchor diameter, and equivalent bond strength were analyzed. The results indicate a critical value of the self-drilling anchor in the sandy gravel strata. In the field test and indoor test, the failure mode of the bolt is the failure of the interface between the anchor body and the soil, and the trend of the load-displacement curve of the bolt is the same. Through an orthogonal test, it was found that the proportion of fine particles has the greatest influence on the anchorage performance of the self-drilling bolt. With the increase in the proportion of fine particles, the peak value of pull-out decreases, indicating that the self-drilling bolt exhibits better anchorage performance in soft soil layers, such as sandy gravel strata. Full article

Plasma-activated water (PAW) is enriched with reactive oxygen and nitrogen species (RONS). Application of PAW in plant cultivation demonstrated that RONS promote seed germination and early plant growth, as well as stimulate plant defense mechanisms. The aim of this paper was to investigate the potential of reactive nitrogen species in PAW to partially replace urea fertilizer nitrogen in lettuce cultivation without resulting in a negative effect on growth and mineral composition. Lettuce was grown under two treatments: urea only and a combined treatment in which 10% of the urea-derived nitrogen was replaced by an equivalent amount of nitrogen supplied via plasma-activated water (PAW). Plant growth parameters of lettuce (number of leaves, head weight, rosette diameter and height, and dry matter weight) were measured. Concentrations of 21 elements in the plants were analyzed using inductively coupled plasma optical emission spectroscopy (ICP—OES). Results showed no significant difference in growth parameters between the two treatments, as well as no significant difference between treatments in the concentrations of most elements except magnesium, boron and sodium. The results demonstrate that PAW reactive nitrogen can partially substitute for nitrogen from synthetic fertilizer without negative effects on the growth and nutritional content of lettuce. The study contributes to the development of sustainable horticultural fertilization practices and the adoption of environmentally friendly technologies. Full article