Search Results (643)

The textile industry generates significant volumes of waste, making the development of reliable methods to evaluate biodegradability a pressing need. While standardised protocols exist for plastics, no specific methodologies have been established for textiles, and the quantification of non-degraded residues is commonly based on mass loss: a measurement that is prone to recovery errors. This study investigated the biodegradation of cotton, polyester, and cotton/polyester blend fabrics in soil under thermophilic conditions using a combined methodological approach. Carbon mineralisation was quantified through a respirometric assay that was specifically adapted for textile substrates, while residual solid fractions were assessed in situ by X-ray microtomography (micro-CT), thus avoiding artefacts associated with sample recovery. Complementary analyses were performed using SEM and FTIR to characterise morphological and chemical changes. Results showed substantial biodegradation of cotton, negligible degradation of polyester, and intermediate behaviour for the cotton/polyester blend. Micro-CT enabled the visualisation of fibre fragmentation and the quantification of the residual. The integration of respirometric, imaging, and spectroscopic techniques provided a comprehensive assessment of textile biodegradability. This study highlights the potential of micro-CT as a non-destructive tool to improve the accuracy and robustness of textile biodegradability assessment by enabling direct quantification of the residual solid fraction that can support future LCA studies and the development of standardised protocols for textile biodegradability. Full article

Characterizing tight reservoirs is challenging due to the complex pore structure and strong heterogeneity at various scales. Current digital rock physics often struggles to reconcile high-resolution imaging with representative sample sizes, and 3D digital cores are frequently used primarily as visualization tools rather than predictive, computable platforms. Thus, a clear methodological gap persists: high-resolution models typically lack macroscopic geological features, while existing 3D digital models are seldom leveraged for quantitative, predictive analysis. This study, based on a full-diameter core sample of a single lithology (gray-black shale), aims to bridge this gap by developing an integrated workflow to construct a high-fidelity, computable 3D model that connects the micro–nano to the macroscopic scale. The core was scanned using high-resolution X-ray computed tomography (CT) at 0.4 μm resolution. The raw CT images were processed through a dedicated pipeline to mitigate artifacts and noise, followed by segmentation using Otsu’s algorithm and region-growing techniques in Avizo 9.0 to isolate minerals, pores, and the matrix. The segmented model was converted into an unstructured tetrahedral finite element mesh within ANSYS 2024 Workbench, with quality control (aspect ratio ≤ 3; skewness ≤ 0.4), enabling mechanical property assignment and simulation. The digital core model was rigorously validated against physical laboratory measurements, showing excellent agreement with relative errors below 5% for key properties, including porosity (4.52% vs. 4.615%), permeability (0.0186 mD vs. 0.0192 mD), and elastic modulus (38.2 GPa vs. 39.5 GPa). Pore network analysis quantified the poor connectivity of the tight reservoir, revealing an average coordination number of 2.8 and a pore throat radius distribution of 0.05–0.32 μm. The presented workflow successfully creates a quantitatively validated “digital twin” of a full-diameter core. It provides a tangible solution to the scale-representativeness trade-off and transitions digital core analysis from a visualization tool to a computable platform for predicting key reservoir properties, such as permeability and elastic modulus, through numerical simulation, offering a robust technical means for the accurate evaluation of tight reservoirs. Full article

Laboratory-scale cryogenic X-ray microtomography was employed for the first time to investigate the early structural evolution of polyurethane (PU) foams. This method enables ex situ studying the internal morphology of the frozen reactive mixture at various times before cell impingement. In this work, the precision of the method was evaluated by studying the early bubble formation and growth under different blowing agents and catalyst contents. It was detected that tripling the catalyst weight content doubled cell nucleation density, from 8.9 × 10⁵ to 1.8 × 10⁶ cells cm⁻³. Yet, doubling the water content has lesser impact on nucleation but leads to fast speeds of cell growth and, in turn, lower relative density at equal reaction times. Overall, it is demonstrated that laboratory cryogenic microtomography can be used to democratise the 3D investigation of the internal structure of foams which was until now only possible in synchrotron facilities. In addition, this method can help elucidate the mechanisms of nucleation and degeneration via directly measuring the density of bubbles and distance between them in the reactive mixture. Finally, this methodology could be extended to recent laboratory nanotomography systems utilizing X-ray tubes with nanometric spot sizes, thereby enabling the confident identification of nucleation events. Full article

Oxidation can lead to intrinsic degradation and loss in the load-bearing capacity of ceramic matrix composites (CMCs) in high-temperature service, thereby compromising structural integrity and operational safety. To elucidate the mechanism of its oxidation effects, this study predicted the oxygen diffusion coefficient within 2.5D woven C/SiC fibre bundles based on gas diffusion and oxidation kinetics theory, and subsequently constructed a meso-scale constitutive model incorporating oxidation damage and fibre defect distribution. Furthermore, a micro-scale framework for yarns was established by integrating interfacial slip behaviour, and an RVE model for 2.5D woven C/SiC was constructed based on X-ray computed tomography reconstruction of the actual microstructure. Building upon this foundation, an oxidation constitutive model applicable to loading–unloading cycles was proposed and validated through high-temperature oxidation tests at 700 °C, 900 °C, and 1100 °C. Results demonstrate that this model effectively characterizes the strength degradation and stiffness reduction caused by oxidation, enabling prediction of CMCs’ mechanical properties under oxidizing conditions and providing a physics-based foundation for the reliable design and life assessment of C/SiC components operating in oxidizing environments. Full article

CubeSats are a fundamental tool of space exploration, allowing for the testing of novel ideas that can be upscaled to more efficient satellite systems. This work presents the development and characterisation of an additively manufactured aluminium mechanism designed to enable the self-functionalisation of CubeSat structures through material extrusion metal additive manufacturing, as a foundation for sensor integration. A space-grade AlSi7Mg alloy was selected and prepared as a filament to print a fully functional hinge geometry, aiming to evaluate the feasibility of producing movable metallic components using a low-cost and sustainable extrusion-based process. Produced parts were subjected to debinding and vacuum sintering, achieving a densification above 85% and an average hardness of 52.2 HV. Further characterisation, including micro-computed tomography, X-ray diffraction and dynamic mechanical analysis, was used to assess the microstructural integrity, present phase, and mechanical behaviour of the sintered components. The designed shrinkage-compensated hinge mechanism preserved its rotational mobility after sintering, validating the mechanical inter-locking strategy and the design for additive manufacturing methodology used. The results demonstrate that material extrusion enables the fabrication of lightweight, functional, and integrated aluminium mechanisms suitable for sensor incorporation and actuation in small satellite systems. This proof-of-concept highlights material extrusion as a sustainable and economically viable route for developing intelligent aero-space structures, paving the way for future adaptive and sensor-integrated CubeSat subsystems. Full article

Lacustrine shale oil in the Chang 7 Member of the Ordos Basin is controlled by a multi-scale pore–throat system in which oil occurrence, spontaneous imbibition, and pore-structure evolution are tightly coupled. In this study, nitrogen adsorption and micro-computed tomography (μCT) were employed to characterize pore-size distribution and connectivity, whereas nuclear magnetic resonance (NMR) T₂ relaxation was utilized to classify oil occurrence states, and X-ray diffraction (XRD) and total organic carbon (TOC) analyses were performed to determine mineralogical and organic compositions. Spontaneous imbibition experiments were conducted at 60 °C and subsequently extended to temperature–pressure sequence tests. The Chang 7 shale exhibits a stratified pore system in which micropores, mesopores, and macropores jointly define a three-tier “micropore adsorption–mesopore confinement–macropore mobility” pattern. As pore size and connectivity increase, the equilibrium imbibed mass and initial imbibition rate both rise, while enhanced wettability (contact angle decreasing from 81.2° to 58.7°) further strengthens capillary uptake. Temperature elevation promotes imbibition, whereas increasing confining pressure suppresses it, revealing a “thermal enhancement–pressure suppression” behavior. μCT-based network analysis shows that imbibition activates previously ineffective pore–throat elements, increasing coordination number and connectivity and reducing tortuosity, which collectively represents a capillary-driven structural reconfiguration of the pore network. When connectivity exceeds a threshold of about 0.70, the flow regime shifts from interface-dominated to channel-dominated. Building on these observations, a multi-scalecoupling framework and a three-stage synergistic mechanism of “pore-throat activation–energy conversion–structural reconstruction” are established. These results provide a quantitative basis for predicting imbibition efficiency and optimizing capillary-driven development strategies in deep shale oil reservoirs. Full article

Deformation bands provide a microscale record of strain localisation within sandstones and offer key insights into deformation mechanisms and conditions. This study integrates detailed field observations with optical microscopy and three-dimensional X-ray microtomography (µCT) to characterise deformation bands in thick-bedded sandstones of the Krosno Formation (Silesian Nappe, Outer Carpathians). Two sections within a regional first-order fold were examined: an upper, mudstone-rich and mechanically weak unit, and an underlying sandstone-dominated competent unit. The contrasting kinematics of the deformation bands reflect layer-parallel strain partitioning during the onset of folding. Normal-shear bands developed in the weaker upper unit, whereas compaction bands formed pervasively in the competent unit. Microstructurally, shear bands are sharply bounded, organised in arrays, and dominated by grain rearrangement with local cataclasis, while compaction bands exhibit diffuse margins, tight grain packing, and disaggregation through progressive cataclasis. These features indicate that the bands formed under shallow-burial (<500 m) conditions. µCT imaging reveals the bands as darker, low-attenuation zones relative to the host rock, reflecting post-deformational cementation and the absence of cement within the bands. This diagenetic contrast enhanced mechanical heterogeneity and promoted later reactivation and fracture development. The study provides a three-dimensional microstructural assessment of early strain localisation in mechanically layered rocks in the buckle fold limb. Full article

This paper provides a comprehensive overview of the application of various radiological modalities, with a critical comparison between human and veterinary medicine. The modalities discussed include conventional radiography, dual-energy X-ray absorptiometry (DXA), computed tomography (CT), magnetic resonance imaging (MRI), ultrasound (US), quantitative ultrasound (QUS), positron emission tomography-computed tomography (PET-CT) and micro and nano computed tomography (micro-CT, nano-CT) in clinical practice and basic research of skeletal system. Radiological imaging plays a crucial role in the diagnosis, monitoring and research of skeletal system disorders in both human and veterinary medicine. In preclinical research, advanced diagnostic imaging modalities such as micro-CT and nano-CT allow for 3D quantification of trabecular and cortical bone microarchitecture for studies in bone biology, regenerative medicine and pharmacological research. Furthermore, the integration of artificial intelligence is advancing image interpretation, precision diagnostics and disease tracking. Despite their broad utility, imaging modalities must be selected based on clinical indication, species, age and anatomical region with consideration of radiation dose, cost and availability, especially in remote regions. For this reason, clinicians and radiologists remain an irreplaceable part of diagnostic imaging. Full article

The depletion of global lithium reserves, coupled with the necessity for environmentally sustainable and economically accessible energy storage systems, has driven the development of sodium-ion batteries (SIBs) as a promising alternative to lithium-ion technologies. Among various anode materials for SIBs, hard carbon exhibits obvious advantages and significant commercial potential owing to its high energy density, low operating potential, and stable capacity retention during prolonged cycling. Biomass represents the most attractive source of non-graphitizable carbon from a practical standpoint, being readily available, renewable, and low-cost. However, the complex internal structure of biomass precursors creates significant challenges for precise control of microstructure and properties of the resulting hard carbon materials, requiring further research and optimization of synthesis methodologies. This work reports the synthesis of hard carbon from Sasa kurilensis via pyrolysis at 900 °C and investigates the effect of alkaline pretreatment on the structural and electrochemical characteristics of the anode material for SIBs. Sasa kurilensis is employed for the first time as a source for non-graphitizable carbon synthesis, whose unique natural vascular structure forms optimal hierarchical porosity for sodium-ion intercalation upon thermal treatment. The materials were characterized by X-ray diffraction, infrared and Raman spectroscopy, scanning electron microscopy, X-ray microtomography and low-temperature nitrogen adsorption–desorption. Electrochemical properties were evaluated by galvanostatic cycling in the potential range of 0.02–2 V at a current density of 25 mAhg⁻¹ in half-cells with sodium metal counter electrodes. The unmodified sample demonstrated a discharge capacity of 160 mAhg⁻¹ by the 6th cycle, with an initial capacity of 77 mAhg⁻¹. The alkaline-treated material exhibited lower discharge capacity (114 mAhg⁻¹) and initial Coulombic efficiency (40%) due to increased specific surface area, leading to excessive electrolyte decomposition. Full article

Additive manufacturing (AM) has rapidly evolved due to its design flexibility, ability to enable personalized fabrication, and reduced material waste. In the medical field, fused filament fabrication (FFF) facilitates the production of individualized anatomical models for surgical preparation, education, medical imaging, and calibration. However, the lack of filaments with X-ray attenuation similar to that of biological hard tissues limits their use in radiological imaging. To address this limitation, a radiopaque filament was developed by incorporating gadolinium oxide (Gd₂O₃) into a biodegradable poly(lactic acid) (PLA) matrix at 1, 3, and 5 wt.%. Thermal and rheological properties were characterized using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and melt flow index (MFI) analyses, revealing minor variations that did not affect printability under standard FFF conditions (200 °C nozzle, 60 °C build plate, 0.12 mm layer height). Microstructural analysis via field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX), elemental mapping, and micro-computed tomography (micro-CT) confirmed homogeneous Gd₂O₃ dispersion without nozzle blockage. Radiopacity was evaluated using gyroid infill cubes, and increasing Gd₂O₃ content enhanced X-ray attenuation, with 3 wt.% Gd₂O₃ reaching Hounsfield Unit (HU) values comparable to cortical bone. Finally, the L1 vertebra phantom fabricated from the 3 wt.% Gd₂O₃ filament exhibited mean HU values of approximately +200 to +250 HU at 50% infill density (trabecular bone region) and around +1000 HU at 100% infill density (cortical bone region), demonstrating the filament’s potential for producing cost-effective, radiopaque, and biodegradable phantoms for computed tomography (CT) imaging. Full article

X-ray micro-computed tomography (Micro-CT) is an advanced technique capable of non-destructive detection of internal defects in materials. Fiber-reinforced polymer (FRP) laminates are prone to forming defects such as pores during the manufacturing process, which significantly affect their mechanical properties. In this study, Micro-CT technology was employed to conduct non-destructive testing on carbon fiber (CFRP), glass fiber (GFRP) and carbon/glass hybrid (C/G) laminates. Combined with the U-Net++ deep learning model, precise segmentation and three-dimensional reconstruction of pores were achieved. A systematic quantitative analysis was carried out on the distribution, size, volume and porosity of pores in six specimens with two layup angles (0/90 and ±45). The research results show that the pores in CFRP are mainly dispersed micro-pores and are relatively evenly distributed; the porosity of GFRP is the highest, and large interlaminar pores are prone to forming. The porosity fluctuates sharply in the thickness direction, revealing that the interlaminar interface is a defect-sensitive area. This provides a reliable quantitative basis and theoretical support for optimization and defect assessment. Full article

Composite silicone rubber insulators are widely used in overhead transmission lines but undergo inevitable aging-induced performance degradation or failure. Understanding their aging process is crucial for optimizing manufacturing and on-site service, yet studies on microstructural changes—especially three-dimensional (3D) microstructural evolution during aging—remain scarce. This study employed X-ray micro-computed tomography (X-ray micro-CT) to characterize and compare the 3D microstructure of one fresh and one field-serviced composite silicone rubber insulator (which underwent 10 years of outdoor service). For the field-serviced insulator, key findings include the following: (1) pore number decreased (from 2200 to 1600), while pore size increased (equivalent diameter: from 3.5 ± 1.3 μm to 10.4 ± 7.2 μm); (2) porosity increased (from 0.04% to 0.69%); (3) new cracks formed (length: 100–900 μm); and (4) pore shape remained nearly unchanged relative to the fresh sample. Notably, the aging depth of the field-serviced insulator was less than 300 μm. These results clarify the 3D microstructural evolution of composite silicone rubber insulators during aging, providing a basis for improving their long-term reliability. Full article

As the most commercially developed metal additive process, laser powder bed fusion (LPBF) is vital to advancing several industry sectors, enabling high-precision part production across aerospace, biomedical, and manufacturing industries. Al 7075 alloy offers low density and high-specific strength yet faces LPBF challenges such as hot cracking and porosity due to rapid solidification, thermal gradients, and a wide freezing range. To address these challenges, this study proposes an integrated computational and experimental framework to enhance the LPBF processability of Al 7xxx alloys by compositional modification. Using the Calculation of Phase Diagram approach, printable Al 7xxx compositions were designed by adding grain refiners (V and/or Ti) and a eutectic solidification enhancer (Mg) to Al 7075 alloy to enable grain refinement and eutectic solidification. Subsequent LPBF experiments and characterization tests, such as metallography (scanning electron microscopy), energy-dispersive X-ray spectroscopy, X-ray diffraction, and X-ray micro-computed tomography, confirmed the production of refined microstructures with reduced defects. This study contributes to existing approaches for producing high-quality Al 7xxx alloy parts without significant compositional deviations using an integrated computational and experimental approach. Finally, aligning with the Materials Genome Initiative, this study contributes to the development and industrial adoption of advanced materials. Full article

This study investigated the representative elementary volume (REV) for visible porosity in horticultural growing media (peat, commercial mixture, treated wood fibre/peat, pure wood fibre) using x-ray micro-computed tomography (µCT) with 2D and 3D image division, pore morphology, water retention curve (WRC), and saturated hydraulic conductivity (K_sat) via pore network modelling (PNM). Two sample sizes (10 × 10 cm, 3 × 3 cm, height × diameter) with resolutions of 46 and 15 µm were analysed. REV was assessed using deterministic (dREV) and statistical (sREV) criteria, evaluating the porosity and coefficient of variation across subvolumes. The results showed that 3D division of large samples achieved REV only for pure wood fibre (8000–10,000 µm), while 2D division met both criteria for all media. For small samples, 3D division achieved REV only for wood fibre/peat mixture, but 2D division succeeded for all media above 3000 µm. Pore analyses indicated that pure wood fibre had the largest, most connected pores, enhancing drainage, while peat showed complex, retentive structures. WRCs aligned well with lab data (R² > 0.88). PNM Ksat estimates from small images were more accurate, with discrepancies (21–172%) due to segmentation artefacts. Future studies should incorporate permeability or tortuosity and explore multiscale imaging for improved hydrophysical predictions. This study also highlights advantages unique to X-ray µCT compared to standard laboratory methods, e.g., direct three-dimensional quantification of pore structure parameters and an image-based determination of the REV. Full article

Radiation-induced lung inflammation (RILI) is a major complication of thoracic radiotherapy, characterized by excessive inflammation and subsequent fibrosis that compromise pulmonary function and treatment outcomes. This study explores the pharmacological properties of a newly synthesized Lipoxin A4 analogue (CYNC-2) to mitigate RILI by modulating the AMP-activated protein kinase (AMPK)/NOD-like receptor family pyrin domain containing 3(NLRP3) inflammasome pathway. A murine RILI model was established in mice by delivering a single high-dose (ablative) X-ray irradiation to the left lung. Mice in the treatment group received CYNC-2 via tail-vein injection three times per week for 2 weeks. The effects of CYNC-2 on RILI were evaluated histological, immunohistochemical analysis of lung tissues, cytokine profiling, lung function testing using a FlexiVent system, and micro-computed tomography (micro-CT) imaging of lung damage. In parallel, two human lung cell lines—L132 (normal bronchial epithelial cells) and A549 (lung carcinoma cells)—were irradiated with 6 Gy X-rays and treated with CYNC-2 to assess cell viability and changes in AMPK/NLRP3 pathway markers via qPCR and immunofluorescence. Lung tissue sample from patients who underwent thoracic radiotherapy were also examined to validate key findings. CYNC-2 activated AMPK and inhibited mTOR signaling, which suppressed NLRP3 inflammasome activation and led to reduced secretion of pro-inflammatory cytokines (IL-1β, IL-6, and TGF-β1). In vitro, CYNC-2 mitigated radiation-induced inflammatory responses and preserved cellular viability. Overall, CYNC-2 effectively dampened acute pulmonary in the RILI model. These findings suggest that targeting the AMPK/NLRP3 inflammasome pathway via a stable LXA4 analogue such as CYNC-2 is a promising therapeutic strategy to improve clinical outcomes for patients receiving thoracic radiation therapy. Full article