Search Results (6,039)

Pipeline leakage is a common issue in many pressurized pipeline systems, with significant hazards, making it a current research hotspot. To reveal the fundamental characteristics of leakage in straight pipelines and 90° elbows transporting different media and thereby predict leakage locations, this paper conducts numerical calculations of the internal flow, while also predicting the pipeline leakage location monitoring model. The study finds that under air medium conditions, the nonlinear function model demonstrates excellent prediction accuracy, with R² > 0.99 for the water₃ condition. Under water medium conditions, the model’s fitting performance gradually weakens with increasing inlet pressure, with R² dropping to 0.77. For a bent pipe, when air is used as the medium, the pressure peak at the large bend angle increases significantly under high inlet pressure. In contrast, when water is the medium, the local pressure reconstruction effect in the bent pipe exhibits a linear strengthening trend as the inlet pressure increases. Full article

This study theoretically investigates the nonlinear optical response of asymmetric dielectric structures embedded with graphene and demonstrates tunable optical bistability in the terahertz frequency range. Our findings reveal that the bistable behavior can be effectively modulated by varying the incident angle, the working wavelength, and the thickness and permittivity of the dielectric layers. In symmetric dielectric configurations, transmittance is enhanced, whereas in asymmetric structures, it is reduced. The thresholds of optical bistability decrease with increasing wavelength of the incident light, while they increase with thicker dielectric layers or higher permittivity of the dielectric medium. Furthermore, widening the bistability range can be achieved by increasing the incident angle. The proposed asymmetric graphene–dielectric layered structure offers a promising platform for the development of advanced terahertz active photonic devices, including optical modulators, optical switches, and mid-infrared functional components. Full article

Objective: This study evaluated whether higher adherence to the Mediterranean Diet (MD), specifically through increased legume consumption, is associated with improved functional, autonomic, and performance parameters in adolescents and young adult competitive swimmers. Methods: Thirty-nine swimmers (mean age 19.7  ±  2.3 years; 22 men, 17 women) monitored over a five-month period under standardized training conditions. Based on baseline dietary assessment, participants were allocated into three groups according to habitual legume intake: Control group (<1 serving/week, no dietary modification), 3Legumes group (~2 servings/week, increased to 3/week), and 6Legumes group (~3–4 servings/week, increased to 6/week). Functional evaluation encompassed bioelectrical impedance parameters (phase angle, extracellular and intracellular water, ECW/ICW ratio), heart rate variability (HRV), cardiac coherence, and critical swimming speed test (CSS) results. Results: After 5 months, the 6Legumes group showed an increase in phase angle (Δ  =  +0.34  ±  0.35°, p  =  0.004), a reduction in extracellular water (Δ  =  −1.77  ±  0.93%, p  <  0.001), and an increase in intracellular water (Δ  =  +1.77  ±  0.93%, p  <  0.001), resulting in a lower ECW/ICW ratio (Δ  =  −0.051  ±  0.028, p  <  0.001). HRV (Δ  =  +6.92  ±  5.02, p  =  0.0003) and cardiac coherence (Δ  =  +0.40  ±  0.35, p  =  0.0015) also demonstrated statistically significant improvements, whereas CSS exhibited a positive trend (Δ  =  +0.011  ±  0.019 m/s, p  =  0.067) without reaching statistical significance. Between-group comparisons confirmed significant differences in phase angle and water-distribution parameters (all p  <  0.01). Conclusions: In this cohort of adolescents and young adult competitive swimmers, increased legume consumption within a Mediterranean dietary framework was associated with beneficial adaptations in cellular hydration status, autonomic regulation, and functional performance. Full article

Hydrophobic nanofiber membranes derived from the biopolymer alginate were fabricated by electrospinning followed by metal ion crosslinking, and their potential as oil-water separation membranes was primarily investigated. Sodium alginate (SA) was co-electrospun with polyethylene glycol and subsequently crosslinked using calcium chloride and group IV metal ions (zirconium or titanium). Metal ion crosslinking changed the surface wettability of the nanofiber membranes, as confirmed by water contact angle measurements. Both zirconium- and titanium-crosslinked SA nanofiber membranes exhibited effective gravity-driven oil–water separation with complete water blocking. Although hydrophobic modification reduced direct water affinity, the resulting membranes retained residual adsorption capability toward methylene blue, indicating the presence of accessible internal polar sites. The adsorption behavior varied depending on the crosslinking ion. In addition, titanium-crosslinked membranes showed an auxiliary UV-assisted dye removal contribution under irradiation, arising from photoactive Ti species. These findings demonstrate that metal ion crosslinking provides a practical route for tuning the functional properties of alginate nanofiber membranes, with oil-water separation as the primary application and dye adsorption/photocatalysis as secondary functionalities. Full article

Growing concern over the environmental impact of conventional plastics has driven the development of biodegradable alternatives. In this context, natural polymers such as starch have emerged as sustainable options. Commercial montmorillonite, implemented as a reference nanomaterial, allows for the enhancement of the properties of biodegradable materials. In this study, commercial cassava starch powder plasticized with water and 35% glycerol, along with commercial nanoclay at concentrations of 0%, 2%, and 4%, was used as film reinforcement. The manufacturing process employed extrusion to evaluate the effectiveness of the nanomaterial in improving the mechanical and functional characteristics of the films. Films with varying concentrations of glycerol and nanoclay were produced to determine the optimal formulation by assessing their rheological, thermal, and mechanical properties. These films were subjected to comprehensive analysis using internationally standardised techniques, including Thermogravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR), and morphological characterisation via Scanning Electron Microscopy (SEM). Among the properties evaluated, water vapour permeability (WVTR) was of particular interest. Results showed that higher nanoclay content improved moisture retention, thus enhancing the films’ water barrier properties. Mechanical testing indicated that the film with the highest nanoclay concentration, F-g35-NC4, displayed tensile strength values of 0.23 ± 0.02 MPa and elongation of 66.90% ± 4.85, whereas F-g35-NC0 and F-g35-NC2 exhibited lower values. Conversely, the highest tear resistance was also recorded for F-g35-NC4, reaching 0.740 ± 0.009 kg. Contact angle measurements revealed a hydrophilic tendency, with values of 89.93° ± 8.78°. Finally, WVTR analysis confirmed that increased nanoclay content enhanced moisture retention and improved the water barrier performance, with a value of 0.030 ± 0.011 g/m²·day, supporting potential applications in the packaging sector. Full article

Management of maxillomandibular transverse discrepancy (MTD) is essential for achieving stable, functional, and esthetic occlusion. This study aimed to evaluate the maxillomandibular transverse dimensions and discrepancies in relation to vertical skeletal patterns using digital dental casts and cone-beam computed tomography (CBCT) images. A total of 180 untreated adult subjects were classified into three vertical groups based on the SN-MP angle: hypodivergent (<27°), normovergent (27–37°), and hyperdivergent (>37°), with 60 subjects in each group. Dental arch widths using casts (DAWs-Casts) were measured at the canine, first premolar, first molar, and second molar, while basal arch widths using casts (BAWs-Casts) were measured at the mucogingival junction apical to the corresponding cusp tips. CBCT images were used to measure basal arch widths (BAWs-CBCT) at the estimated centers of resistance (CRes). DAW-Cast, BAW-Cast, and BAW-CBCT measurements were affected by vertical skeletal patterns. Therefore, maxillomandibular dimensions and discrepancies vary according to vertical skeletal pattern, underscoring the need for careful evaluation when planning treatment protocols for patients with MTD. Full article

We investigated the properties of boxy/peanut-shaped (B/PS) bulges in a sample of 71 galaxies from the Edge-on Galaxies in the Pan-STARRS Survey (EGIPS) and 20 simulated galaxies from Illustris TNG50 using multicomponent photometric decomposition. For each real and simulated galaxy, we obtained a suitable photometric model in which the B/PS bulge was represented by a dedicated 2D photometric function. For real galaxies, we found that more flattened X-structures are generally residing in larger B/PS bulges. When tested against the galaxy masses, we verified that both larger bulges and more flattened X-structures are typically found in more massive galaxies. Since large bars are also known to reside in more massive galaxies, we conclude that the flatness of X-structures in larger B/PS bulges has a physical origin, rather than being solely a result of projection effects due to differences in observed bar viewing angles. When comparing the properties of B/PS bulges between EGIPS galaxies and TNG50 galaxies, with bars rotated for different viewing angles, we found that B/PS bulges in TNG50 are considerably smaller and less luminous in terms of total intensity. This is consistent with previous studies of bar properties in TNG50, indicating the B/PS bulges in TNG50 differ from those in real galaxies, as do their parent bars. Full article

Background and Clinical Significance: Tramadol-associated acute angle-closure crisis is rare and has been reported only once previously following subcutaneous administration. Acute angle closure may occur in anatomically predisposed individuals in the setting of perioperative physiological stress, with medications acting as contributory factors. Case Presentation: A 38-year-old woman developed a bilateral acute angle-closure crisis shortly after initiating oral tramadol for postoperative pain relief following an uncomplicated robotic-assisted laparoscopic hysterectomy. Within 24 h, she experienced headache, nausea, vomiting, periocular pain, and blurred vision. Ophthalmic examination revealed markedly elevated intraocular pressure (45 mmHg OD, 39 mmHg OS), corneal epithelial edema, mid-dilated pupils, and completely closed angles on gonioscopy. Prompt intraocular pressure–lowering therapy followed by bilateral Nd:YAG laser peripheral iridotomy resulted in full anatomical and functional recovery, with visual acuity returning to baseline within 48 h. Conclusions: In this case, extreme anatomical susceptibility due to significant hyperopia and very short axial lengths likely played a dominant role, with perioperative physiological factors contributing to pupillary dilation. Oral tramadol may have acted as a permissive factor lowering the threshold for angle closure rather than as a sole causative agent. Awareness of this potential association is important to facilitate early ophthalmic referral and prevent unnecessary diagnostic evaluations. Full article

Trajectory tracking and self-balancing capacity is crucial for an unmanned bicycle robot (UBR) applied in off-road trails and narrow space. However, self-balancing is hard to be guaranteed once the steering angle manipulates for the tracking task, both of which are closely linked to the steering angle, especially for the UBR without auxiliary mechanism. In this paper, we introduce a double closed-loop framework in which the outer loop controller plans the desired speed and heading angle to track the reference trajectory, and the inner loop controller track the desired signals obtained from the outer loop to maintain balance. To be specific, a saturated velocity planner is developed to realize fast convergence of tracking error considering the kinematic constraints in the outer loop. A fuzzy sliding model controller (FSMC) is designed to attenuate the chattering effect via adapting its control gain in the inner loop, and a radial basis function neural network (RBFNN) approximator is also integrated into the framework to enhance the adaptability and robustness against bounded disturbances. The feasibility and effectiveness of the proposed control framework and approaches are validated based on the Matlab and Gazebo environment. In particular, the UBR can follow the testing route with lateral deviation less than 0.5 m in the presence of lateral winds and physical parameter measurement error, and comparative simulation results highlighted the superiority of the proposed control scheme. Full article

Understanding how supercritical CO₂ and water interact with mineral surfaces is essential for predicting the stability and sealing performance of geological storage formations. Yet, the combined effects of mineral surface chemistry and confined pore geometry on interfacial structure and fluid dynamics remain insufficiently resolved at the molecular scale. In this study, molecular dynamics simulations were employed to quantify how methylated SiO₂, hydroxylated SiO₂, and kaolinite regulate CO₂–H₂O interfacial behavior through variations in wettability and electrostatic interactions. The results show a clear hierarchy in water affinity across the three minerals. On methylated SiO₂, the water cluster remains spherical and poorly anchored, with a contact angle of ~140°, consistent with the weakest water–surface Coulomb attractions (only −400 to −1400 kJ/mol). Hydroxylated SiO₂ significantly enhances hydration, forming a cylindrical water layer with a reduced contact angle of ~61.3° and strong surface–water electrostatic binding (~−18,000 to −20,000 kJ/mol). Kaolinite exhibits the highest hydrophilicity, where water forms a continuous bridge between the two walls and the contact angle further decreases to ~24.5°, supported by the strongest mineral–water electrostatic interactions (−23,000 to −25,000 kJ/mol). Meanwhile, CO₂–water attractions remain moderate (typically −2800 to −3500 kJ/mol) but are sufficient to influence CO₂ distribution within the confined domain. These findings collectively reveal that surface functionalization and mineral type govern interfacial morphology, fluid confinement, and electrostatic stabilization in the sequence methylated SiO₂ < hydroxylated SiO₂ < kaolinite. This molecular-level understanding provides mechanistic insight into how mineral wettability controls CO₂ trapping, fluid segregation, and pore-scale sealing behavior in subsurface carbon-storage environments. Full article

To achieve low-cost and flexible wheel angles measurement, we propose a novel strategy that integrates wheel segmentation network with 3D vision. In this framework, a semantic segmentation network is first employed to extract the wheel rim, followed by angle estimation through ICP-based point cloud registration. Since wheel rim extraction is closely tied to angle computation accuracy, we introduce APCS-SwinUnet, a segmentation network built on the SwinUnet architecture and enhanced with ASPP, CBAM, and a hybrid loss function. Compared with traditional image processing methods in wheel alignment, APCS-SwinUnet delivers more accurate and refined segmentation, especially at wheel boundaries. Moreover, it demonstrates strong adaptability across diverse tire types and lighting conditions. Based on the segmented mask, the wheel rim point cloud is extracted, and an iterative closest point algorithm is then employed to register the target point cloud with a reference one. Taking the zero-angle condition as the reference, the rotation and translation matrices are obtained through point cloud registration. These matrices are subsequently converted into toe and camber angles via matrix-to-angle transformation. Experimental results verify that the proposed solution enables accurate angle measurement in a cost-effective, simple, and flexible manner. Furthermore, repeated experiments further validate its robustness and stability. Full article

Osteoarthritis (OA) is a progressive degenerative joint disease that fundamentally alters the mechanical environment of the knee. This study utilizes a finite element framework to evaluate the biomechanical response of the distal femur in healthy and osteoarthritic conditions across critical functional postures. To isolate the bone’s inherent structural stiffness and avoid numerical artifacts, a free-body computational approach was implemented, omitting external surface fixations. The distal femur was modeled as a linearly elastic domain with material properties representing healthy tissue and OA-induced degradation. Simulations were performed under passive gravitational loading at knee flexion angles of $0^{\circ },{60}^{\circ },$ and ${90}^{\circ }$. The results demonstrate that the mechanical response is highly sensitive to postural orientation, with peak von Mises stress consistently occurring at ${60}^{\circ }$ of flexion for both models. Quantitative analysis revealed that the stiffer Normal bone attracted significantly higher internal stress, with a reduction of over 30% in peak stress magnitude observed in the OA model at the most critical flexion angle. Total displacement magnitudes remained relatively stable across conditions, suggesting that OA-induced material softening primarily influences internal stress redistribution rather than global structural sag under passive loads. These findings provide a quantitative index of skeletal vulnerability, supporting the development of patient-specific orthopedic treatments and rehabilitation strategies. Full article

Although membrane proteins are of major importance in both physiology and disease, they remain less studied than soluble proteins due to the complex amphiphilic environments required to preserve their structure and function. As a consequence, membrane proteins are under-represented in structural databases. In this work, we present a robust structural characterization of lipid nanodiscs designed to facilitate membrane protein studies by small-angle neutron scattering. By combining small-angle X-ray and neutron scattering, we investigate nanodiscs of three different sizes and three lipid compositions to accommodate a broad range of systems. Specifically, nanodiscs with diameters of approximately 9 nm, 12 nm, and 15 nm were examined. Beyond the commonly used di-myristoyl-phosphatidylcholine lipid, we produced and characterized polar lipid extracts from a Gram-negative bacterium (Escherichia coli) and a Gram-positive bacterium (Bacillus subtilis) under both protonated and deuterated conditions. In conclusion, solubility-enhanced variants of the scaffold protein yield more stable nanodiscs and are therefore preferable for extended structural investigations. The co-fitting of small-angle scattering data provides robust geometrical models of these nanodiscs, which can be treated as well-defined reference systems for future studies of membrane proteins in native-like lipid environments. Full article

We demonstrate the enhancement of antibacterial and cytocompatibility characteristics of femtosecond laser-treated pure titanium and Ti-6Al-4V titanium alloy samples suitable for orthopedic implant applications. We controlled the wettability of the titanium samples by tailoring the surface geometry using a femtosecond laser. To increase the hydrophobicity, laser-assisted micro-grids patterning was performed on the titanium samples, where we achieved a highest contact angle of 144.6° for a 1 µL de-ionized water droplet. In contrast, the hydrophobic Ti-6Al-4V titanium alloy surfaces were converted to hydrophilic surfaces by fabricating periodic micro-gratings on the samples’ surface, where a lowest contact angle of 19.84° was achieved. Furthermore, we assessed the biocompatibility of the micro-patterned titanium samples by investigating the antibacterial activity against Staphylococcus Aureus bacteria. Moreover, the cytocompatibility of the micro-patterned titanium samples was examined using NCTC Clone 929 (L-929) mouse fibroblasts. The laser-treated titanium samples exhibited enhanced antibacterial performance while maintaining excellent cell compatibility. The experimental results confirmed excellent correlation with the wettability of the laser-patterned samples and their antibacterial characteristics and cytocompatibility. Overall, the findings highlight femtosecond laser surface structuring as a highly effective strategy to simultaneously improve antibacterial behavior and the biocompatibility of implant materials, offering a promising way for the advanced functionalization of orthopedic implants. Full article

In this study, the influence of the electrochemical oxidation process on Ti-Grad 23 alloy (Ti6Al4V ELI) in 1 M H₃PO₄, under applied voltages between 200 and 275 V, at a constant time of 1 min, is analyzed. The structural, morphological, and wettability properties of the TiO₂ anodic layers obtained were investigated by X-ray diffraction (XRD), energy dispersive electron microscopy (SEM-EDS), contact angle measurements, and chemical corrosion. XRD analysis showed the development and intensification of anatase and brookite phases, with increased crystallite size after electrochemical oxidation. SEM/EDS characterization confirmed the formation of an inhomogeneous porous TiO₂ layer, with pore diameters ranging from 98 to 139 nm and a significant increase in oxygen content. Contact angle measurements demonstrate enhanced hydrophilicity for all oxidized samples, with progressively lower values as the applied voltage increased. Chemical corrosion tests in Ringer solution and Ringer + 40 g/L H₂O₂ indicated that oxidized surfaces maintain structural stability in physiological media, whereas exposure to oxidizing environments induces partial pore closure and crack formation due to localized corrosion. The optimal anodizing condition was identified at 200 V for 1 min, yielding a uniform distribution of pores and improved morpho-functional characteristics suitable for biomedical applications. The optimal electrochemical oxidation conditions were identified at 200 V for 1 min, ensuring a uniform pore distribution. Full article