Search Results (360)

Transparent objects such as glass containers, test tubes, and plastic bottles are common in robotic manipulation scenarios, but their refractive and reflective surfaces produce incomplete RGB-D geometry and make task-specific grasp selection unreliable. This paper presents an integrated vision-language system for transparent object perception and task-oriented grasping. First, we construct VLM-DRE, a transparent object image instruction dataset with 12,700 images and 38,100 image-instruction-bounding-box triplets. LoRA fine-tuning of Molmo-7B improves target click accuracy from 86.4% to 91.5% and IoU@0.75 from 57.5% to 69.1%. Second, MSR-Net performs monocular depth completion and mask prediction using multi-scale adaptive feature fusion and progressive feature refinement, achieving RMSE 0.066, mAP 98.61%, and IoU 94.12% on Syn-TODD, and RMSE 0.118, mAP 99.02%, and IoU 87.95% on ClearPose. Third, LMF-Net combines RGB-D cross-modal fusion with learnable multi-factor matching to rank AnyGrasp 6-DoF candidates, reaching 77.8% Top-1 and 90.5% Top-3 accuracy on TaskGrasp-Image and improving PRISM-Real success from 61.1% to 68.5%. On a RealSense D435i–Unitree Z1 Pro platform, the complete system obtains 85.4% success with manual clicks and 71.3% with VLM-predicted clicks, supporting perception-to-grasping integration while highlighting target localisation and runtime as deployment bottlenecks. Full article

In this study, the effect of stacking sequence on the mechanical behavior and damage evolution of carbon- and glass-fiber-reinforced hybrid composite tubes manufactured by the filament winding method was experimentally investigated. The tubes were produced from E-glass and carbon fibers in a Huntsman epoxy matrix, with an inner diameter of 22.5 mm and an outer diameter of 28.5 mm, in two configurations that differ in both the fiber placed in each layer and its winding angle: an inner [±45]₂ carbon layer/outer [±75]₂ glass layer (C45) and an inner [±45]₂ glass layer/outer [±75]₂ carbon layer (G45). The fiber volume fractions ranged from 0.53 to 0.61 and the measured densities from 1.68 to 1.84 g/cm³. Five specimens per configuration (n = 5) were tested under radial compression and three-point bending, and their fracture mechanisms were characterized by scanning electron microscopy (SEM) and optical microscopy. Energy absorption was quantified through the specific energy absorption (SEA). Under radial compression, the C45 configuration exhibited a higher peak force (4209 ± 322 N versus 3573 ± 136 N) and a higher SEA (2.64 ± 0.13 J/g versus 2.06 ± 0.03 J/g). Under three-point bending, C45 again reached a higher flexural strength (92.8 ± 4.5 MPa versus 85.1 ± 3.0 MPa); however, despite failing at a markedly lower peak force, the G45 configuration absorbed a comparable total energy (66.96 ± 2.83 J versus 62.88 ± 6.26 J) and reached a comparable SEA (1.13 ± 0.06 J/g versus 1.08 ± 0.14 J/g), reflecting the ductility-driven damage tolerance imparted by the glass inner layer. Across all metrics, the G45 configuration displayed a consistently lower coefficient of variation (e.g., 3.82% versus 7.64% for radial peak force), indicating greater reproducibility and structural predictability. SEM observations revealed that the C45 specimens failed through sudden fiber fracture and delamination driven by the high stiffness mismatch, indicating brittle behavior, whereas the G45 specimens exhibited progressive damage through matrix crushing and fiber pull-out. The findings indicate that the C45 configuration is favorable where maximum load-bearing capacity and stiffness are targeted, whereas the G45 stacking sequence is advantageous where energy absorption, damage tolerance, and predictable progressive failure are critical. Full article

Various models exist for predicting the sound absorption coefficient of porous materials, including the capillary model within the Rayleigh model. However, many of these models require an acoustic parameter known as ventilation resistance, which is difficult to determine theoretically for fibrous materials such as wool. This study theoretically estimated the sound absorption coefficient of glass wool using computed tomography (CT) images. Voids within the glass wool were approximated as clearances in two parallel planes. Sound absorption characteristics were theoretically estimated by determining the propagation constant and characteristic impedance within these voids. Furthermore, the theoretical analysis accounted for the tortuosity of the material. During CT image processing, corrections were applied to approximate the actual fiber surface area by accounting for the fiber inclination relative to the direction of sound wave incidence. This correction was determined by approximating the fiber cross-section visible in the CT image as an ellipse and using the resulting ellipticity. A two-microphone impedance measurement tube was used to measure the normal incident sound absorption coefficient. The proposed method provides fundamental insights into the model-based development of sound-absorbing materials and is expected to contribute to cost reduction by eliminating the need for conventional air permeability tests. Full article

Platelet-rich fibrin (PRF) has been widely used in regenerative dentistry because of its potential to support tissue regeneration. Recently, modifications in PRF preparation protocols and tube surface characteristics have attracted attention because of their possible influence on fibrin organization and biologic activity. The present in vitro study aimed to evaluate the effects of nano-hydroxyapatite platelet-rich fibrin (HA-PRF) on gingiva-derived mesenchymal stem cells (GMSCs) by comparing it with leukocyte platelet-rich fibrin (L-PRF) and titanium platelet-rich fibrin (T-PRF). Gingival tissue and venous blood samples were obtained from a systemically healthy male volunteer. PRF membranes were prepared using conventional glass tubes, nano-hydroxyapatite-coated tubes, and titanium tubes. GMSCs were isolated, characterized, and cultured with PRF membranes. Cell viability and metabolic activity were evaluated using MTT analysis. Apoptosis and necrosis rates were assessed by Annexin V/PI flow cytometry. VEGF and TGF-β1 release levels were determined by ELISA, whereas IL-1β, IL-6, and TNF-α gene expression levels were analyzed using qRT-PCR. The HA-PRF and L-PRF groups demonstrated higher cell viability values compared with the T-PRF group on day 7. Annexin V/PI analysis revealed no statistically significant differences between the groups in terms of apoptosis and necrosis. Growth factor release and cytokine gene expression profiles demonstrated time-dependent biologic responses in all PRF membranes. Within the limitations of this study, HA-PRF showed no evidence of cytotoxicity and demonstrated biologic responses comparable to those observed with conventional L-PRF. Both HA-PRF and L-PRF generally exhibited more favorable cellular responses than T-PRF under the present experimental conditions. Full article

Background/Objectives: With increasing frequency in sublobar resections, accurate intraoperative localization has become essential to ensure adequate resection margins and spare lung parenchyma. Our study evaluates the efficacy of shape-sensing robotic bronchoscopy (SS-RAB) with integrated mobile cone-beam CT (mCBCT) for intraoperative localization of lung tumors using indocyanine green (ICG). We further aimed to explore the feasibility of a single intubation-single positioning technique for bronchoscopy and surgery. Methods: We retrospectively reviewed patients who underwent SS-RAB with integrated mCBCT for ICG marking, followed by minimally invasive sublobar resection. ICG marking was deemed successful when it allowed the operative team to localize and resect the lesion with adequate pathology margins. Results: A total of 28 patients with 30 pulmonary lesions from a single institution were included. Median tumor size was 10.5 mm (IQR, 8.7–14.6 mm) and distance from pleura 7.8 mm (IQR, 2.45–13.8 mm). Twenty lesions (66.6%) were solid, 5 lesions (16.6%) semi-solid, and 5 lesions (16.6%) ground-glass. ICG localization was successful in 28 lesions (93%). Nineteen patients (68%) were intubated only with a double-lumen endotracheal tube (DL-ETT), used for bronchoscopy and surgery, and in 10 patients (36%) ICG marking and surgery were both performed in lateral decubitus. One patient developed a small pneumothorax during bronchoscopy which did not prevent ICG injection. Conclusions: SS-RAB with integrated mCBCT for ICG marking is successful and safe. Single intubation with DL-ETT and lateral decubitus positioning for both bronchoscopy and surgery are feasible. Further studies are needed to prove a potential increase in efficiency with this technique. Full article

The bubble tube of a glass curing furnace was subjected to extreme heat–flow coupling conditions for a long time due to the scouring of melt flow caused by the gas flow bubbling in a high-temperature molten glass environment at 1150 °C, resulting in severe corrosion and structural failure. This paper conducts post-service sampling analysis of an Inconel 690 bubble tube, and systematically studies its corrosion morphologies, product distribution and corrosion mechanisms. The results show that the outer wall of the bubble tube undergoes an oxidation reaction in the high-temperature molten glass to form a Cr-rich oxide layer. However, local spalling occurs under the scouring of the molten glass flow, resulting in continuous corrosion. The corrosion behavior shows obvious asymmetry. The average corrosion rate near the bubble flow side (the inner curve side, 0.118 mm/day) is significantly higher than that on the outer side (0.051 mm/day) due to the higher partial pressure of oxygen and greater flow rate of molten glass. It reveals the synergistic mechanism by which fluid scouring continuously removes the protective Cr-rich oxide scale, thereby accelerating the oxidation–erosion cycle under the heat-flow coupling effect. The results provided experimental evidence and theoretical reference for the material optimization and life prediction of bubble tubes. Full article

This paper investigates flow resistance and heat transfer during flow boiling of HFE-649 in a vertical annular minigap formed between an outer glass tube and an inner copper tube heated by a centrally located cartridge heater. Two variants of the copper heating surface were examined: a smooth surface and an enhanced surface produced by threading. The experimental measurements included fluid temperature and pressure at the inlet and outlet of the minigap, wall temperature along the test section, and the electrical parameters of the heater. The total pressure drop was analyzed using the Lockhart–Martinelli approach, with the Fanning friction factor calculated from a correlation in the literature and from an empirical relation fitted to the present dataset. Because the available pressure drop dataset is limited, the latter relation is treated here as a preliminary, geometry-specific fitting used as an auxiliary input for the present calculations rather than as a generally validated correlation. The resulting pressure drop estimates were then used to determine an effective axial velocity profile in the minigap. The thermal analysis was based on a system of steady-state energy equations for the copper tube and the fluid. The coupled inverse problems were solved using the Trefftz method, which provided two-dimensional temperature distributions in both domains and enabled the calculation of local heat transfer coefficients at the solid–fluid interface. The wall temperature results obtained using the Trefftz method were cross-checked against the Fourier-transform-based solution, with both approaches giving similar results. For the dataset considered, the empirical friction factor relation provided lower mean relative differences in pressure drop prediction than the literature relation, particularly for the smooth surface. The reconstructed wall temperature field showed good agreement with the measurements, while validation of the fluid temperature field was limited to the inlet and outlet data. For the present operating conditions, the results indicate that the threaded surface modifies local heat transfer behaviour only moderately and does not produce a pronounced overall enhancement over the entire minigap length. Full article

To address the challenges of limited samples, class imbalance, and real-time requirements in surface defect detection for solar vacuum glass collector tubes, this study proposes an improved lightweight RT-DETR-based method. Specifically, DICM is introduced into the backbone to improve multi-directional and multi-scale feature extraction, HAFB is embedded in the neck to enhance the fusion of local details and global semantics, and transfer learning is adopted to alleviate data scarcity under small-sample conditions. Experiments on a self-built defect dataset of solar vacuum glass collector tubes show that the proposed method outperforms the original RT-DETR and several mainstream detectors in terms of Precision, Recall, mAP@0.5, and F1-score while maintaining favorable inference speed and model compactness. Under the same hardware conditions, the proposed model achieves an mAP@0.5 of 0.95, an inference speed of 83.21 FPS, and a model size of 82.36 MB. These results demonstrate the feasibility of the proposed method for real-time online defect detection in industrial scenarios. Full article

The main aim of the work was to analyse the microstructure and selected properties of a metal-matrix surface composite reinforced with a product of vitrification of asbestos-cement waste (ACW) and glass cullet from cathode-ray tubes (CRTs). The composite matrix was an AA7075 (Al-5.5Zn-2.4Mg-1.6Cu-0.2Cr) aluminium alloy. The FSP (friction stir processing) method was used to produce the composite. The composites were tested in the context of the possibility of using vitrified material as a substitute for other reinforcing materials. As a result of treatment, a composite surface layer was obtained, characterised by uniform distribution of the reinforcing phase with a good bond with the matrix. This process was accompanied by strong grain refinement in the stirring zone and partial dissolution of intermetallic phases. These microstructural changes, combined with the introduction of hard particles into the metal-matrix, resulted in a significant increase in the composite’s hardness and wear resistance. As a result of the conducted research, it was found that using the product of vitrification of ACW and CRT cullet in the composites manufacturing process is beneficial, as it is not only a competitive solution to other reinforcing phases, but also an effective way to manage waste hazardous to the environment and humans, thus adding new functionalities to products processed in this way. Full article

Permeability evolution in hydrate-bearing porous media is a key factor controlling gas production efficiency during natural gas hydrate exploitation. In this study, laboratory experiments were conducted using sand-packed tubes filled with quartz sand and glass beads to systematically investigate the variation of liquid-phase permeability with hydrate saturation. The effects of pore structure, particle size, and initial gas injection pressure on hydrate formation and permeability reduction were analyzed. Furthermore, experimental results were compared with four commonly used permeability models, including the Kozeny model, the Dai model, the Masuda model, and the parallel capillary model. The results show that permeability decreases continuously with increasing hydrate saturation in both porous media, and the most rapid decline occurs at low saturation levels between 0 and 9%. Under the same conditions of 20–40 mesh and an initial pressure of 6.0 MPa, the pressure drop rate in the quartz-sand-packed tube reaches 1.062 kPa per minute, which is about 2.35 times higher than the 0.451 kPa per minute observed in the glass-bead-packed tube, indicating a faster hydrate formation rate and stronger permeability reduction in quartz sand. In addition, both increasing particle mesh size and raising the initial gas injection pressure significantly promote methane consumption and hydrate formation. Model comparison results demonstrate that permeability reduction is strongly dependent on pore structure. The Kozeny pore-filling model, the Dai model (M = 3), and the Masuda model (N = 8) show good agreement with the glass-bead data, whereas the Dai model (M = 8), the Masuda model (N = 15), and the pore-center form of the parallel capillary model better describe the quartz-sand system. In contrast, models based on particle-surface coating show poor agreement in both media. These findings indicate that permeability reduction is primarily controlled by pore-space occupation and flow-path restriction rather than uniform surface coverage. The results suggest that hydrate growth is more likely to occur in pore centers and critical pore-throat regions, although this conclusion is based on macroscopic model comparison and requires further validation by pore-scale observations. This study provides a quantitative basis for model selection and improves the understanding of permeability evolution in hydrate-bearing porous media. Full article

This work presents a compact microwave sensor for noninvasive blood glucose monitoring based on a substrate-integrated waveguide loaded with a complementary split-ring resonator on RO4350. The sensing principle uses shifts in resonance frequency and changes in S-parameters to track the dielectric dispersion of glucose-containing tissue. The resonator is constructed using Substrate-Integrated Waveguide (SIW) technology, which mimics the propagation characteristics of a conventional rectangular waveguide. To validate its versatility, the sensor implements three practical sample delivery modes: direct liquid contact with the sensing surface, a glass tube holder mounted over the active region, and a non-invasive fingertip interface. Electromagnetic simulations and benchtop measurements confirm clear glucose-dependent frequency shifts with stable matching and insertion levels. Across the physiological range of 20 to 200 mg·dL⁻¹, the sensor exhibits clear glucose-dependent resonance shifts in all configurations. In direct contact mode, the resonance frequency shifts from 10.83 GHz to 10.45 GHz with sensitivities up to 2.47 MHz per mg·dL⁻¹. The tube configuration shows a shift from 10.49 GHz to 10.38 GHz with sensitivity up to 0.80 MHz per mg·dL⁻¹, while reducing contamination. In the non-invasive fingertip mode, the resonance shifts from 2.56 GHz to 2.52 GHz with sensitivities up to 0.25 MHz per mg·dL⁻¹. These results confirm the sensor’s compactness, reliability, and suitability for portable, low-cost glucose monitoring. The results indicate that the proposed sensor can support practical continuous or spot monitoring and offers a clear path toward portable and low-cost glucose assessment. Full article

Plastic pollution represents a significant challenge for the building industry, where synthetic foils are extensively used as acoustic absorbers or vapour barriers but persist in the environment for decades, causing risks to ecosystems and human health. In addition, conventional construction materials such as concrete and glass often provide poor acoustic performance, leading to a growing reliance on synthetic acoustic absorbers. In this study, we propose alginate—a biopolymer derived from brown seaweed—as an alternative sustainable material for indoor acoustic conditioning. Thin, bendable, and transparent alginate foils were fabricated and characterized in the impedance tube to assess their sound absorption properties. Results reveal that alginate foils achieve acoustic absorption coefficients comparable to conventional synthetic-based absorbers, while offering biodegradability and a renewable origin. Their physical properties further support potential integration into indoor architectural design, where flexible and transparent properties are desirable. Overall, the findings highlight alginate’s potential as an environmentally friendly replacement for synthetic acoustic foils, supporting the goals of acoustic sustainability and the associated long-term impacts of plastic pollution in the built environment. Full article

Direct steam generation in parabolic trough collectors presents challenges due to the non-uniform distribution of heat flux and the appearance of flow patterns. These conditions can induce stresses, deformations, and deflections that compromise the structural integrity of the absorber tube; therefore, this study developed a coupled numerical model (optical, thermohydraulic, thermal, and thermoelastic) capable of reproducing the absorber tube’s behavior under real operating conditions. The methodology includes the following: (i) an optical model using Monte Carlo ray tracing to obtain the non-uniform distribution of solar heat flux and the local concentration ratio; (ii) a two-fluid thermohydraulic model to describe the transition from subcooled liquid to superheated vapor; (iii) a thermal conduction model; and (iv) an analytical thermoelastic model to quantify stresses, deformations, and deflections. The results identify the region near 421.35 m as the most critical, where circumferential temperature differences reached 28.38 K, generating maximum deformations between 600 and 800 με and deflections up to 18 mm along a 25 m section, 1 mm about to touch the glass cover. These findings demonstrate that this model facilitates the identification of critical conditions and the assessment of structural risks, contributing to improved reliability and safety in parabolic trough solar thermal power plants. Full article

This study experimentally investigates the residual axial compression behavior of circular glass fiber-reinforced polymer (GFRP) tube-confined concrete short columns (CFGFT) after exposure to elevated temperatures. A total of 27 specimens were fabricated and tested under axial compression, with key parameters including GFRP tube wall thickness (5, 8, and 10 mm), exposure temperature (100, 150, 200, and 300 °C), and constant temperature duration (60 and 120 min). The results show that the load–displacement responses of CFGFT short columns after elevated temperature exposure exhibit distinct two-stage characteristics, culminating in brittle failure at the ultimate axial capacity. Wall thickness significantly influences the failure modes of the specimens, while elevated temperatures increase the occurrence of unfavorable failure modes. Temperature is identified as the primary factor governing the degradation of residual axial capacity and initial stiffness, with performance deterioration becoming more pronounced at temperatures exceeding 200 °C. In contrast, the effect of constant temperature duration within the range of 60–120 min is relatively limited. Based on the experimental results, a simplified binary quadratic regression model incorporating the coupled effects of temperature and wall thickness is proposed to predict the post-fire axial capacity reduction factor (Kr), with a coefficient of determination (R²) of 0.901. These findings provide experimental evidence and a practical predictive approach for the fire-resistant design and post-fire safety assessment of CFGFT members. Full article

This study evaluates the performance of single concrete-filled frictional Fibre-Reinforced Polymer (FRP) piles embedded in saturated liquefiable sand and subjected to seismic loading using a shaking table. A unidirectional shaking table equipped with a 1000 mm × 1000 mm × 1000 mm laminar shear box with 27 lamina rings was utilized in the study. FRP tubes manufactured from epoxy-saturated Carbon Fibre-Reinforced Polymer (CFRP) and Glass Fibre-Reinforced Polymer (GFRP) fabrics were filled with 35 MPa concrete and allowed to cure for 28 days, serving as model piles for the experimental programme, with cylindrical concrete prisms employed to represent the behaviour of traditional piles. Pile dimensions and properties based on scaling relationships were selected to account for the nonlinear nature of soil–pile systems under seismic loading. Scaled versions of ground motions from the 2010 Val-des-Bois and 1995 Hyogo-Ken Nambu earthquakes were implemented as input motions in the tests. The results show limited variation in the inertial and kinematic responses of the piles, especially before liquefaction. Head rocking displacements were within 5% of each other during liquefaction. Post liquefaction, the concrete-filled FRP piles showed lower response compared to the traditional concrete pile. The results suggests that concrete-filled FRP piles, especially those made from carbon fibre, provide practical alternatives for use. Full article