Search Results (9,089)

Membrane fouling reduces permeate flux and treatment efficiency, yet most diagnostic methods are destructive and require offline analysis. Optical coherence tomography (OCT) enables in situ, real-time visualization; however, quantitative image extraction of thin foulant layers is often limited by manual processing and subjective thresholding. Here, we develop a reproducible OCT image-analysis workflow that combines band-pass filtering, Gaussian smoothing, and unsharp masking with a dual-threshold subtraction strategy for automated fouling-layer segmentation. Seventeen global thresholding algorithms in ImageJ (289 threshold pairs) were benchmarked against SEM-measured cake thickness, identifying Triangle–Moments as the most robust combination. For humic-acid fouling, the OCT-derived endpoint thickness (14.23 ± 1.18 µm) closely agreed with SEM (15.29 ± 1.54 µm). The method was then applied to other microfiltration foulants, including kaolin and sodium alginate, to quantify thickness evolution alongside flux decline. OCT with the optimized image analysis captured rapid early deposition and revealed periods where flux loss continued despite minimal additional thickness growth, consistent with changes in layer permeability and compaction. The proposed framework advances OCT from qualitative visualization to quantitative, real-time fouling diagnostics and supports mechanistic interpretation and improved operational control of membrane systems. Full article

Clarifying the mechanical properties and failure patterns of layered coal–rock combinations in coal-measure strata is critical to guiding hydraulic fracturing design in petroleum and mining engineering. This paper investigates the mechanical properties, failure patterns, and stress distributions of sandstone–coal–sandstone (SCS) and mudstone–coal–mudstone (MCM) combinations under different confining pressures and thickness ratios based on the 3D combined finite–discrete element method (3D FDEM). The results show that the mechanical strength of the SCS combination is higher than that of the MCM combination under the same conditions. As the thickness ratio increases, the overall peak stress and elastic modulus of the combination decrease gradually and eventually approach those of the pure coal. As confining pressure increases, the peak stress of layered coal–rock combinations rises gradually, plastic behaviors become increasingly prominent, and the failure mode of the mudstone layer transitions from tensile-dominated to shear-dominated. Under different thickness ratios and confining pressures, the coal layer in the combinations primarily develops shear-dominated cracks, whereas the sandstone layer mainly generates tensile-dominated cracks. An increase in confining pressure elevates the critical thickness ratio for sandstone layer failure in the SCS combination. Essentially, the changes in stress state caused by rock types, thickness ratios, and confining pressures are important reasons for the variations in the failure patterns of each layer in layered coal–rock combinations. The key findings of this paper are expected to provide theoretical guidance for the field design of petroleum and coal mine engineering. Full article

Compact antennas with ultra-wideband operation and stable radiation are essential for portable and airborne ground-penetrating radar (GPR), yet miniaturization in the sub 3 GHz region is strongly constrained by the wavelength-driven aperture requirement and often leads to impedance discontinuity and radiation instability. This paper presents a compact aperture-slot antipodal Vivaldi antenna (AS-AVA) designed under a radiation stability-driven co-design strategy, where the miniaturization features are organized along the energy propagation path from the feed to the flared aperture. The proposed structure combines (i) aperture-slot current-path engineering with controlled meandering to extend the low-frequency edge, (ii) four tilted rectangular slots near the aperture to restrain excessive edge currents and suppress sidelobes, and (iii) back-loaded parasitic patches for coupling-based impedance refinement to eliminate residual mismatch pockets. A fabricated prototype on FR-4 (thickness 1.93 mm) occupies $111.15\times 156.82$ mm² and achieves a measured $S_{11}$ below $-10$ dB from 0.63 to 2.03 GHz (fractional bandwidth 105.26%). The measured realized gain increases from 2.1 to 7.5 dBi across the operating band, with stable far-field radiation patterns; the group delay measured over 0.6–2.1 GHz remains within 4–8 ns, indicating good time-domain fidelity for stepped-frequency continuous-wave (SFCW) operation. Finally, the antenna pair is integrated into an SFCW-GPR testbed and validated in sandbox and outdoor experiments, where buried metallic targets and a subgrade void produce clear B-scan signatures after standard processing. These results confirm that the proposed AS-AVA provides a practical trade-off among miniaturization, broadband matching, and radiation robustness for compact sub 3 GHz GPR platforms. Full article

Magnetron-sputtered coatings consisting of multiple alternating layers of chromium and amorphous carbon (Cr/a-C)ml were deposited on HS6-5-2 steel with an intermediate chromium layer by varying deposition rates. Three series of coatings, S1, S2, and S3, with thicknesses of 1.74, 1.15, and 1.14 μm and average chromium contents of 89.3, 66.0, and 59.7 wt.% Cr, respectively, were obtained. Open-circuit potential, cyclic potentiodynamic measurements, and electrochemical impedance spectroscopy were used to characterize their corrosion resistance in 3.5% NaCl. The surfaces were observed with optical and scanning electron microscopy before and after the corrosion tests, and changes in the elemental composition were monitored by energy-dispersive spectroscopy. The protective properties of coatings from series S2 and S3 are similar and significantly better than those of S1. They are characterized by a corrosion current below 1 μA cm^–2 and a stable passive state up to over 0.9 V_Ag/AgCl. The coatings have cathodic behavior towards the substrate, and when the coatings are damaged, galvanic corrosion causes deep pits. Coatings deposited at lower rates and with higher carbon content demonstrate significantly enhanced corrosion resistance in 3.5% NaCl. All three series of Cr/(Cr/a-C)ml@HS6-5-2 exhibit identical corrosion behavior after compromising the coatings’ integrity. Full article

Metallized papers or cardboards, used when high barrier properties are required in packaging, are usually coated with white ink prior to printing to ensure accurate colors and high print quality. The coating provides well-controlled sorption properties at a certain thickness, allowing for better printability and reduced penetration of ink components into the substrate. The white ink used for coating ensures the dimensional stability of the substrate after the drying process is complete. This research compares how different numbers of white base coat layers affect the print quality of multicolor offset prints onto metallized cardboard after rubbing. A high print quality assessment after rubbing was obtained based on spectrophotometric and gloss measurements. A comparison of the number of white base coat layers on metallized cardboard indicated that multicolor prints with two base coat layers have lower reflectance, better color stability, and high print quality after rubbing. Gloss measurements showed that prints with one layer of white base coat exhibited higher gloss values, while rubbing led to a moderate increase in gloss for all samples. Ultimately, a thicker layer of white base coat enhances mechanical resistance while maintaining acceptable optical properties in multicolor prints on metallized cardboards. Full article

This study investigates the technological and chemical causes of early zinc-coating degradation on cold-formed steel sections produced from DX51D+Z140 galvanized coils. Commercially manufactured products exhibiting early corrosion symptoms were used in this study. The entire processing route, which included strip preparation, cold rolling, hot-dip galvanizing, passivation, multi-roll forming, storage, and transportation to customers, was analyzed with respect to the residual surface chemistry and process-related deviations that affect the coating integrity. Thirty-three specimens were examined using electromagnetic measurements of coating thickness. Statistical analysis based on the Cochran’s and Fisher’s criteria confirmed that the increased variability in zinc coating thickness is associated with a higher susceptibility to localized corrosion. Surface and chemical analysis revealed chloride contamination on the outer surface, absence of detectable Cr(VI) residues indicative of insufficient passivation, iron oxide inclusions beneath the zinc coating originating from the strip preparation, traces of organic emulsion residues impairing wetting and adhesion, and micro-defects related to deformation during roll forming. Early zinc coating degradation was shown to result from the cumulative action of multiple technological (surface damage during rolling, variation in the coating thickness) and environmental (moisture during storage and transportation) parameters. On the basis of the obtained results, a methodology was proposed to prevent steel product corrosion in industrial conditions. Full article

We present the design and characterization of a fully automated free-standing liquid crystal (FSLC) film holder, enabling remote and precise control of liquid crystal (LC) volume release, wiping speed, and temperature. Using 4-octyl-4′-cyanobiphenyl (8CB) as a test material, we systematically investigated the influence of formation parameters on the resulting film thickness and temporal evolution. Thickness measurements performed by monitoring the difference in optical path lengths of two arms of a standard optical intensity autocorrelation setup reveal that the wiping speed is the dominant factor determining both the initial film thickness and the subsequent annealing dynamics, while temperature becomes relevant only at the highest wiping speeds. Faster wiping speeds consistently produce thinner and more uniform FSLC films on the order of 3 µm, due to reduced LC mass deposition. Time-resolved optical and X-ray scattering measurements confirm the presence of an annealing phase following film formation, which can last for between 1 s and 10 min time scales, until a stable smectic configuration is reached. The holder provides a reliable and fully remote tool for generating high-quality FSLC films at rates up to 1 Hz, suitable for optical to hard X-ray experiments where direct access to the sample environment is limited. Full article

The influence of electron beam treatment parameters (electron gun speed, electron beam current, scanning frequency, and sweep type) on the structure and properties of the surface layer of the composite material AlMg3-5SiC has been investigated. Composite specimens of AlMg₃ alloy reinforced with 5 wt.% silicon carbide particles were manufactured via the stir casting process. Experimentally, processing modes with heat input from 120 to 240 J/mm yield a modified layer thickness from 74 to 1705 µm. Heat input should not exceed 150 J/mm to ensure a smooth and defect-free surface layer. The macro- and microstructure were examined using optical microscopy. Brinell hardness was measured. Friction and wear tests were performed under dry sliding friction conditions using the “bushing on plate” scheme. This evaluated the tribological properties of the composite material in its original cast state and after modifying treatment. Due to the matrix alloy structure refinement by 5–10 times, the surface layer’s hardness increases by 11% after treatment. The modified specimens have superior tribological properties to the initial ones. Wear rate reduces by 17.5%, the average friction coefficient reduces by 32%, and the root mean squared error of the friction coefficient, which measures friction process stability, reduces by 50% at a specific load of 2.5 MPa. Therefore, the electron beam treatment process is a useful method for producing high-quality and uniform wear-resistant aluminum matrix composite surface layers. Full article

Background and Objectives: Patients with type 2 diabetes mellitus (T2DM) and ischemic stroke present with endothelial, vascular and left ventricular (LV) myocardial dysfunction. We investigated the effects of treatment with either glucagon-like peptide-1 receptor agonists (GLP-1RA) or sodium-glucose contrasporter-2 inhibitors (SGLT-2i) on endothelial glycocalyx, arterial stiffness, and LV myocardial strain in patients with metformin-treated T2DM and a prior ischemic stroke. Materials and Methods: A total of 54 consecutive patients with T2DM and ischemic stroke who attended a cardiometabolic outpatient clinic in Athens, Greece, and received either GLP-1RA (dulaglutide; n = 27) or SGLT-2i (empagliflozin; n = 27) were enrolled in the study. We measured the perfused boundary region (PBR) of the sublingual microvessels, a marker of glycocalyx thickness, as well as carotid-femoral pulse wave velocity (PWV) and LV global longitudinal strain (GLS), at baseline and at 4 and 12 months of treatment. Results: Twelve months after treatment, all patients had reduced glycosylated hemoglobin and body mass index (BMI) (p < 0.001). Patients treated with dulaglutide showed a greater reduction in BMI (−11.8% vs. −4.8%, p < 0.001) compared to those treated with empagliflozin. Compared to baseline, all patients had reduced PBR, PWV and GLS (p < 0.001) after 12 months of treatment. However, empagliflozin presented a greater decrease in PWV (−14% vs. −10.9%, p = 0.041), while dulaglutide resulted in a greater increase in GLS (14.7% vs. 8.3%, p = 0.024) compared to empagliflozin. In all patients, the reduction in PBR at 12 months was correlated with a decrease in PWV and with an increase in GLS (p < 0.05). Conclusions: Both dulaglutide and empagliflozin improve cardiovascular function in T2DM patients with ischemic stroke. Dulaglutide appears to be more effective in the improvement of LV myocardial strain, whereas empagliflozin is more effective in reducing arterial stiffness. Full article

Background: The clinical meaning of hip joint synovial cavity thickness (HJSCT) on ultrasound (US) in juvenile idiopathic arthritis (JIA) without effusion is uncertain. Methods: In this cross-sectional study, we analyzed 369 children (187 JIA; 182 controls) undergoing hip US at a referral center in Kraków, Poland. JIA examinations were performed upon initial referral, early in the care pathway. We excluded patients with hip effusion and pre-existing inflammatory, traumatic or degenerative hip pathology. HJSCT was defined as the distance from the outer capsule margin to the femoral neck cortex. We used a Toshiba Aplio 400 system with a 12 MHz probe to measure and derive mean bilateral HJSCT. Bilateral concordance was assessed. Iterative multivariable linear regression modeling was used to compare groups, adjusting for non-linear age effects (natural splines) and WHO height-for-age z-scores (HAZ). Results: Left–right HJSCT agreement was high (ICC 0.947; mean difference 0.03 mm; 95% limits of agreement −0.64–0.70). In unadjusted analysis, mean (SD) HJSCT was similar in JIA versus controls: 5.83 (1.09) vs. 5.95 (0.99) mm, respectively (p = 0.25). In the final model (adj. R2 0.656), HJSCT was strongly associated with age (non-linear, p < 0.001) but not significantly associated with HAZ (β = 0.04; p = 0.11) or JIA status (β = 0.07; p = 0.30). Predicted HJSCT showed a steep increment in childhood and plateau in adolescence. Conclusions: In children without hip effusion, HJSCT mainly reflects physiological growth and does not differ significantly between early JIA patients and healthy controls. These findings suggest that capsular thickening is not a reliable standalone marker for early disease in the absence of effusion. Full article

Studies on two-dimensional materials (such as topological insulators or transition metal dichalcogenides) have shown that they exhibit unique properties, including high charge carrier mobility and tunable bandgaps, making them attractive for next-generation electronics. Some of these materials (e.g., HfSe${}_2$) also offer thickness-dependent bandgap engineering. However, the standard device fabrication techniques often introduce processing contamination, which reduces device efficiency. In this paper, we present a modified mechanical exfoliation technique, the Reversed Structuring Procedure, which enables the fabrication of hybrid systems based on 2D microflakes with improved interface cleanness and contact quality. Hall effect measurements on Bi${}_2$Se${}_3$ and HfSe${}_2$ devices confirm enhanced electrical performance, including the decrease in the measured total resistance. We also introduce a novel Star-Shaped Electrode Structure, which allows for accurate Hall measurements and the exploration of geometric magnetoresistance effects within the same device. This dual-purpose geometry enhances the flexibility and demonstrates broader functionality of the proposed fabrication method. The presented results validate the Reversed Structuring Procedure method as a robust and versatile approach for laboratory test-platforms for electronic applications of new types of layered materials whose fabrication technology is not yet compatible with CMOS. Full article

Background: The pterygoid plates serve as crucial reference points for posterior maxillary surgery and the placement of pterygoid implants; however, population-specific morphometric reference values remain underexplored for adults of Asir region (Abha city) of Saudi Arabia. Methods: This retrospective cross-sectional cone beam computed tomography (CBCT) study analyzed the archived scans obtained at King Khalid University Dental Hospital. Of 100 randomly selected adult CBCT scans collected between June and October 2025, 50 images met the eligibility criteria. The analyses were conducted using OnDemand3D software to measure the bilateral pterygoid plates’ length, thickness at the maximum diameter, and medial-lateral divergence angle. Styloid process length was measured as an exploratory variable. Three calibrated examiners performed the measurements, and the reliability was assessed using interclass correlation coefficients. Results: Fifty CBCT scans met the inclusion criteria (30 males, 20 females). The mean lateral pterygoid plate length was 14.61 ± 3.69 mm on the right and 13.83 ± 3.93 mm on the left, while the mean medial plate length was 11.27 ± 3.52 mm (right) and 11.98 ± 3.82 mm (left). Side to side paired comparisons showed no significant right–left differences in lateral plate length (mean R–L 0.79 mm, 95% CI −0.48 to 2.06), lateral thickness (mean 0.04 mm, 95% CI −0.14 to 0.22), medial thickness (mean 0.01 mm, 95% CI −0.19 to 0.21), or pterygoid angulation (mean 1.99°, 95% CI −1.07 to 5.05), supporting bilateral symmetry. Bilateral correlations were strong for medial plate length (r = 0.729, p < 0.001) and angulation (r = 0.632, p < 0.001). Males had a longer right lateral plate than females (15.74 ± 3.55 mm vs. 12.93 ± 3.31 mm; mean difference 2.81 mm, 95% CI 0.80–4.82; p = 0.007), whereas other measurements did not differ by sex. Plate thickness ranged from approximately 1.33 to 1.46 mm and left medial plate thickness correlated negatively with left medial plate length (r = −0.399, p = 0.004). Styloid process length averaged 22.99 ± 9.76 mm and showed no significant association with pterygoid plate measures. Conclusions: CBCT-derived findings demonstrated overall bilateral symmetry and limited dimorphism in relation to sex. These region-specific morphometries support individualized preoperative posterior maxillary surgery and pterygoid implant planning. Full article

Background: Cellulite is a highly prevalent condition with dermal and subcutaneous alterations poorly captured by visual grading systems. Ultrasound has emerged as a non-invasive imaging modality capable of objectively quantifying morphological features relevant to cellulite. This systematic review evaluated the evidence on ultrasound for the diagnosis, structural characterization, and treatment monitoring of cellulite, identifying methodological limitations and research gaps. Methods: This systematic review (PROSPERO:CRD420251185486) followed the PRISMA statement. Searches were conducted in PubMed, Scopus, and CENTRAL up to November 2025. Risk of bias was evaluated using ROBINS-I and the Newcastle–Ottawa Scale. Results: Nine studies involving 785 participants were included. Ultrasound frequencies ranged from 12 to 35 MHz, with some scanners operating across broader bandwidths. Despite variability in devices, acquisition protocols, and clinical comparators, all studies consistently demonstrated that ultrasound quantifies key structural characteristics of cellulite. Diagnostic investigations reported moderate-to-strong correlations (r ≈ 0.31–0.64) between ultrasound-derived measures and clinical severity scores. Interventional studies showed measurable reductions in dermal and subcutaneous thickness, decreased adipose protrusion height, and improved dermal echogenicity across multiple treatment modalities. Ultrasound frequently detected microstructural remodeling not readily visible on clinical examination. Conclusions: Ultrasound is a valuable imaging modality for objectively characterizing cellulite and monitoring treatment-induced tissue remodeling. Standardized acquisition protocols, validated analytic criteria, and larger controlled studies are needed to support integration into routine dermatologic and esthetic practice. The quantitative and reproducible nature of ultrasound-derived parameters also provides a suitable foundation for future integration with data-driven and artificial intelligence–based image analysis frameworks. Full article

The main objective of this work is to assess the potential negative impact of organic farming on the thyroid gland and compare it with the negative impact of conventional farming on this organ. Previous studies have linked exposure to conventional farming with thyroid disruption; relatively less is known about effects of exposure to organic farming on the thyroid. Mus musculus were the bioindicators in this work, captured in a conventional farm (CF), an organic farm (OF), and two reference areas (RF’) without agriculture. Histomorphometric and histomorphological measurements of the thyroid were performed. Hypothyroidism signs were observed in mice exposed to either farming system, being less pronounced in organic farming-exposed mice: epithelium thickness and the epithelial cells’ area and volume were lower than in non-exposed mice [epithelium thickness (µm): 4.16 ± 0.51 (CF); 6.28 ± 0.19 (OF); 7.46 ± 0.25 (RF’)]. Histomorphologic alterations included decreased follicular sphericity, increased epithelium irregularity, increased exfoliation into the colloid, and increased inflammation of thyroid tissue. Results suggest that, while organic farming might be a better alternative to conventional farming, it is not completely free of health hazards. Exposure to an organic farming environment can cause thyroid disruption, although with less pronounced effects than conventional farming. Despite there being risks to be considered, results support the benefit of transitioning from conventional farming systems towards organic farming systems. Full article

To investigate the complex interaction in multi-structure systems, this study establishes a refined 3D numerical model based on a transportation hub project in Tianjin to analyze the asymmetric coupling deformation mechanism of a deep excavation adjacent to a shared-wall metro station and elevated bridge piles. This study highlights the transition from soil-mediated interaction mechanisms to those dominated by structures under shared-wall constraints. Results show that the existing station acts as a high-stiffness boundary, effectively suppressing lateral-wall deflection and basal heave on the proximal side. A critical finding is the reversal of the station’s deformation mode: while stations with a soil buffer typically tilt toward the excavation, the shared-wall station exhibits a clockwise rotation away from the excavation; this phenomenon is driven by excavation-induced basal rebound directly transferred through the common diaphragm wall. Furthermore, the station exerts a significant “shielding effect” on adjacent bridge piles, shifting their maximum lateral displacement from the pile head to the toe and reducing overall deformation. Parametric analyses reveal that optimizing shared-wall thickness is more effective for controlling lateral deformation, whereas increasing wall depth primarily mediates vertical heave. This study concludes that, for shared-wall systems, design priorities must shift from settlement control to anti-heave measures, and pile monitoring should extend to the deeper critical zones identified in this study. Full article