Search Results (1,721)

A comprehensive experimental dataset for unidirectional carbon fiber pultruded composites is presented, including mechanical testing results, microscopy images, and X-ray computed tomography volumes. In contrast to typical datasets, all measurements consistently describe a single material system, encompassing both the composite and its constituents (carbon fibers and vinyl ester matrix), thereby enabling a comprehensive and coherent multiscale material characterization. X-ray-computed tomography images of samples extracted from three pultruded composite profiles were acquired with a voxel size of 0.55 µm and analyzed to determine the fiber orientation distribution. Scanning electron microscopy with a pixel size of 0.098 µm was used to determine the overall and local fiber volume fractions. Compression testing of 17 composite specimens provided the compressive properties. The tensile and shear properties of the matrix were obtained from tensile and shear tests on seven and four matrix specimens, respectively. The Ramberg-Osgood model was fitted to the matrix’s tensile stress–strain response. Single-fiber tensile testing was conducted on 255 carbon fibers with three gauge lengths to determine fiber properties and Weibull parameters. All mechanical tests were performed up to material failure. The dataset is suitable for semi-analytical predictions and numerical finite-element modeling of composite mechanical behavior. Full article

Background/Objectives: Trabecular bone exhibits brittle behaviour governed by microscale deformation and damage, yet quantifying crack progression is difficult because classical fracture-mechanics approaches do not apply to architecturally discontinuous porous tissue. This pilot study evaluates whether synchrotron X-ray computed tomography (XCT) combined with digital volume correlation (DVC) can provide a practical, geometry-normalised approach for quantifying crack-opening behaviour in human trabecular bone. Methods: Semicylindrical specimens from femoral heads of hip-fracture donors (n = 5) and non-fracture controls (n = 5) underwent stepwise three-point bending during XCT imaging. Full-field displacement maps were used to measure crack mouth opening displacement (CMOD), crack length (a), and their ratio CMOD/a, used here as a geometry-normalised comparative descriptor of brittle response rather than an intrinsic material property. Automated phase-congruency crack detection (PCCD) was compared with manual measurement. Results: XCT–DVC resolved three-dimensional displacement discontinuities during crack initiation and propagation in all specimens. Hip-fracture donors exhibited significantly lower critical crack-opening ratios (CMOD/a)* than Controls (median 0.31 vs. 0.47; p = 0.008) and reached instability at lower applied loads. Total crack extension (Δa*) was similar between groups. Automated crack tracking using phase-congruency-based segmentation showed excellent agreement with manual measurements (r² = 0.98), supporting reliable extraction of crack geometry from DVC displacement fields. Conclusions: In this small pilot sample, XCT–DVC provided a feasible, geometry-normalised approach for comparing crack-opening behaviour where classical fracture-mechanics parameters cannot be applied. The close agreement between automated and manual crack measurements supports the reproducibility of the displacement-based measurement pipeline. The lower critical CMOD/a in hip-fracture specimens may indicate a more brittle comparative response. However, given the small sample, differing sex distribution, and lower bone volume fraction in the hip-fracture group, these findings are preliminary and require confirmation in larger cohorts. Establishing whether the observed difference reflects intrinsic tissue brittleness, architectural factors, or both is an important objective for future work in microstructure-matched cohorts. Full article

Currently, existing studies primarily perform damage simulations based on random aggregate mesoscale models of concrete. In contrast, research on freeze–thaw numerical simulations based on realistic concrete mesostructural models remains relatively scarce. In this study, based on X-ray computed tomography (CT) scanning technology, the influence of freeze–thaw action on the pore structure evolution law of aeolian sand self-compacting concrete (ASSCC) was analyzed. Mesoscale characteristics of the mortar, aggregates, and pores were extracted using image processing software, and a realistic mesostructural model of ASSCC was subsequently established. Furthermore, numerical simulations of the freeze–thaw cycle process were conducted using the finite element software ABAQUS. The results indicated that during the initial freeze–thaw stage, the formation of small new pores predominated within the concrete. As the freezing and thawing cycles progressed, these pores gradually interconnected and coalesced into larger irregular pores, which eventually led to the development of penetrating cracks that resulted in structural failure of the ASSCC. The mesostructural model derived from CT data effectively simulated the failure patterns and mechanical performance of ASSCC under both uniaxial compression and freeze–thaw conditions. This provides an effective means for predicting the mechanical properties of concrete under freeze–thaw cycling conditions. Full article

Lithium-ion batteries experience structural degradation during operation and storage, which can negatively impact performance, safety, and service life. Early identification of these degradation-induced structural changes is important for battery health assessment and reliability monitoring. This study proposes a deep learning-based framework for classifying the structural condition of 18650 lithium-ion batteries using X-ray micro-computed tomography (µCT) images. The proposed approach combines centroid-based core cropping, image normalization, three-slice stacking, and transfer learning using a fine-tuned InceptionResNet-V2 architecture. Three adjacent µCT slices are stacked into an RGB-like representation to preserve local three-dimensional structural information while maintaining compatibility with a two-dimensional convolutional neural network. The original classification head of InceptionResNet-V2 was replaced with a custom classification block consisting of dropout layers, fully connected layers, and a SoftMax classifier optimized for battery condition recognition. The framework was evaluated using four battery structural conditions: pristine, cycle-aged, calendar-aged, and thermally cycled cells. Experimental results demonstrated an overall classification accuracy of 96.62%, with a precision of 95.62%, sensitivity of 96.94%, specificity of 98.92%, and F1-score of 96.20%. Comparative analysis with previously reported battery imaging studies demonstrated that the proposed framework achieves competitive performance while addressing the challenging task of structural condition classification from µCT imagery. The results demonstrate the potential of combining advanced X-ray imaging and transfer learning for automated lithium-ion battery structural health assessment and degradation monitoring. Full article

Microalgae–fungal pellets have been studied as a versatile and robust biotechnological platform, offering significant advantages for microalgal biomass harvesting, wastewater treatment, biofuels production and/or obtaining of value-added products. This review presents an integrated analysis of the mechanisms governing the formation, stability, and functionality of these systems, combining physicochemical, biological, and mathematical modelling approaches and aims to describe the current state of the art and main research needs. The aggregation process is strongly influenced by the complementarity of the surface properties of microalgae and filamentous fungi, including electrostatic interactions, production of extracellular polymeric substances (EPSs), and modifications in surface roughness. Recent advances in multiscale characterization techniques, such as confocal microscopy, micro-computed tomography, atomic force microscopy, and X-ray photoelectron spectroscopy, have allowed a more precise elucidation of the internal architecture and surface chemistry of the pellets. In parallel, biological characterization through enzymatic assays, oxidative stress biomarkers, and photosynthetic activity analyses has provided relevant information on the metabolic responses and functional resilience of the consortium. Additionally, the incorporation of mathematical flocculation models can contribute to the prediction of pellet growth, density, and stability, supporting process optimization and application. The understanding of these interaction phenomena is important for the design of high-yield and efficient systems, including their development and validation, to expand the use of microalgae–fungal pellets in bioprocesses, as evidenced by this review. Full article

Mechanical damage remains a major constraint in low-damage harvesting and handling of the Korla fragrant pear, owing to its cultivar-specific bruise-sensitive traits (BSTs), namely its thin peel, crisp flesh, smooth epidermis, and high bruise sensitivity. This review synthesizes evidence from the Korla fragrant pear, other pear cultivars, apple, and related fresh produce to clarify damage mechanisms and engineering strategies for damage control. The reviewed studies show that injury is mainly governed by impact energy, compression load, contact stiffness, friction, fruit velocity, spacing, and transfer trajectory. Quasi-static compression and drop-impact tests provide essential thresholds, including elastic modulus, rupture force, absorbed energy, bruise area, and bruise volume, but Korla-specific data remain insufficient. Nondestructive techniques are complementary: RGB machine vision supports rapid surface screening, hyperspectral imaging improves early bruise detection, X-ray computed tomography quantifies internal bruising, and scanning electron microscopy verifies cellular damage mechanisms. FEM and DEM can predict stress distribution, deformation, collision behavior, and equipment-induced injury when calibrated with cultivar-specific parameters. Overall, apple- or general pear-based technologies require recalibration before application to the Korla fragrant pear. Future work should establish Korla-specific damage thresholds and validate detection, simulation, and conveying systems under real orchard and packing-line conditions. Full article

Background: Ununited anconeal process (UAP) is one of the four primary causes of elbow dysplasia (ED). Radiography (X-ray) and computed tomography (CT) are commonly employed imaging techniques for the diagnosis of elbow dysplasia. The objective of this retrospective study was to evaluate the frequency and distribution of UAP in dogs referred for elbow imaging and to analyze the coexistence of this disorder with other primary causes of ED, such as medial coronoid process disease (MCPD), osteochondritis dissecans (OCD), and joint incongruity (IC). Methods: The study population comprised 108 dogs of both sexes, aged between 3 and 15 months, of breeds predisposed to ED: 69 German Shepherds, 23 Labrador Retrievers, and 16 Golden Retrievers. All dogs underwent both radiographic and CT examinations of the elbow joints. Categorical data were analyzed using Fisher’s exact test to evaluate breed-related findings and lesion coexistence, with significance set at 5%. Inter-method reliability was assessed using Cohen’s kappa coefficient (ĸ). Results: Based on radiographic and CT findings, elbow dysplasia was diagnosed in 53 dogs and 58 dogs, respectively. UAP was identified in 9 cases and only in German Shepherds. Among the 9 UAP-positive dogs, coexistence with other ED lesions (most commonly medial coronoid process disease and joint incongruity) was observed in 8 cases. For specific UAP detection, both imaging modalities demonstrated perfect diagnostic agreement (ĸ = 1.0). Conclusions: UAP was the rarest diagnosed primary etiology of elbow dysplasia in the study population. This disorder has been found only in German Shepherds; however, this observation should be interpreted with reservation due to the unequal breed distribution within the study population. Radiography and computed tomography demonstrated equivalent diagnostic agreement for UAP identification; this result should also be interpreted cautiously due to the limitation of the small number of identified cases of this disorder. Furthermore, UAP occurred more frequently as a concomitant lesion—most commonly in association with medial coronoid process disease and joint incongruity—rather than as a solitary finding. Full article

Industrial hemp (Cannabis sativa L.) is increasingly being recognized for the production of functional food ingredients and nutraceutical products with broad applications in human nutrition. Its nutrient-rich seeds are of particular interest for their nutritional profile. Moreover, its inflorescences and trichomes provide sources of nutrient-rich proteins, bioactive compounds, and functional substances for food formulations. Agronomic practices, environmental factors, and genotype considerably influence the hemp nutritional profile; thus, continued interdisciplinary research is needed to standardize quality across supply chains. X-ray micro-computed tomography (micro-CT) combined with 3D image analysis is an emerging non-destructive technique in high-resolution plant phenotyping. The aim of this work was to show the contribution of X-ray micro-CT to the quantitative characterization of the internal hemp seed structure and of the trichomes. The 3D image analysis approach used allowed us to determine many morphometric traits of the different seed parts and of the trichomes. Among them, volume ratios of the different seed parts and the density and morphological characteristics of the trichomes of two cultivars were accurately quantified. Overall, this work showed the contribution of X-ray micro-CT in 3D morphometric characterization of the hemp achene structure and trichomes. The obtained seed morphometric traits could be correlated in future applications with nutritional and/or physiological properties of different hemp varieties in order to support different aspects of the whole hemp supply chain such as the dehulling process, oil and protein recovery, seed quality evaluation, and genotype screening, to which trichome characterization could also contribute. Full article

Crystal size distributions (CSDs) of metamorphic minerals provide quantitative constraints on nucleation-growth kinetics and metamorphic thermal regimes. Early interpretations linked CSD shape to type of metamorphism, associating near-linear CSDs with rapid-contact metamorphism and bell-shaped CSDs with prolonged regional metamorphism. Subsequent works showed that diffusion-controlled nucleation and growth can also produce bell-shaped CSDs without annealing, leaving unresolved how contrasting thermal regimes are expressed in interface-controlled systems. The Fangshan tectonic dome at the northern margin of the North China Craton comprises multiple metamorphic zones, recording Mesozoic contact metamorphism of Fangshan plutons and a concealed pluton in the Nanjiao area. We employed high-resolution X-ray micro-computed tomography (micro-CT) to quantify the 3D crystal size distributions of garnets of contact metamorphic samples from the Nanjiao area and the Fangshan contact aureole. Integrated 3D CSDs with spatial statistics, reconstructed nucleation curves, garnet compositional zoning, and thermodynamic phase equilibrium modeling were used to decipher crystallization kinetics in interface-controlled systems. Nucleation and growth of garnets from the Nanjiao area, and one sample from the Fangshan contact aureole, which is separated from the main heat source by an earlier intruded magma body, are interface-controlled, and display bell-shaped CSDs together with sigmoidal nucleation curves that record a progressive increase followed by a gradual decline in nucleation rate. Phase equilibrium modeling and garnet compositional profiles of a sample from Nanjiao demonstrate that the late-stage deceleration of nucleation in interface-controlled systems is fundamentally driven by whole-rock constituents’ exhaustion rather than the geometric impingement of diffusion halos. In contrast, another contact sample, which is collected near the main heat source, is diffusion-controlled, and displays a steep J-shaped nucleation curve with a delayed, broad peak nucleation rate followed by rapid late-stage suppression. The 3D textures of these metamorphic rocks suggest that contact and regional thermal regime alone do not determine garnet population characteristics; bell-shaped CSDs can be produced in contact metamorphic environments. We propose that heating rate is the primary control on the resulting crystal size distributions. Full article

Advances in imaging and fabrication technologies offer new opportunities to develop tools that support the visualization and understanding of complex biological materials. This contribution presents a comprehensive methodological framework for generating anatomically representative, species-specific 3D models of wood microstructure, intended to enhance student comprehension in wood science and related fields. The workflow integrates micro-X-ray computed tomography (micro-CT) scanning, image segmentation, STL model preparation, and additive manufacturing. Using micro-CT, we captured high-resolution, non-destructive 3D datasets of four wood species—European beech (Fagus sylvatica), oak (Quercus robur L.), Norway spruce (Picea abies), and Scots pine (Pinus sylvestris). The resulting volumetric data were processed with dedicated software to isolate and reconstruct key anatomical features, which were subsequently converted into printable STL models. These models were fabricated at a 1:400 scale using filaments composed of 40% wood particles and 60% biodegradable polylactic acid (PLA), underscoring the relevance of sustainable materials in educational tool development. The primary aim of this work is to document and justify each stage of the technological process, thereby providing a replicable pathway for producing detailed, pedagogically useful representations of wood microstructure. The resulting models are publicly available on the Sketchfab platform as part of the “3D Wood Micro Structure Collection.” Full article

This study presents an approach to quantifying impact-induced damage severity in composites, focusing on synthetic carbon fibre-reinforced polymer (CFRP), natural flax fibre-reinforced polymer (FFRP) and hybrid fibre reinforced polymer (HFRP) composite of carbon and flax. The investigation aims to quantitatively characterise impact damage under energies ranging from 10 to 70 J through acousto–ultrasonics (AU) testing, proposing an efficient technique for evaluating the integrity of various FRP composites under in-service conditions. AU testing was performed at azimuthal angles of 0°, 30°, 45°, 60° and 90°, utilising acousto–ultrasonic waveform indices (AUWIs), such as wave velocity, peak amplitude, energy content, centroid frequency and skewness factor. The damage severity index is correlated with the damage mode. The findings establish that wave velocity is a reliable parameter for quantifying damage severity across all composite material types considered, with high adjusted R² values of 0.92 for CFRP, 0.89 for FFRP and 0.90 for HFRP. Peak amplitude also shows considerable sensitivity. Finally, this research highlights the limitations of traditional non-destructive evaluation (NDE) techniques and demonstrates the potential of combining multi-damage metrics with advanced imaging methods, such as X-ray micro-computed tomography (X-ray µCT) and scanning electron microscopy (SEM), to provide a comprehensive assessment of damage in various composite materials. The proposed methodology offers a promising approach for quantifying the impact damage severity in composite structures, as applicable to wind turbine blades, amongst other structural components. Full article

Self-compacting concrete (SCC) is widely adopted in complex structural engineering due to its excellent flowability and filling capacity. However, in harsh corrosive environments, its complex internal pore structure can easily serve as a preferential pathway for the transport of aggressive media, leading to durability deterioration. This study systematically investigates the effects of chemical attack inhibitor (CAI) on the workability, mechanical properties, sulfate attack resistance, and chloride ion penetration resistance of SCC. The micro-mechanisms governing pore structure evolution are elucidated using low-field nuclear magnetic resonance (LF-NMR) and X-ray computed tomography (X-CT). At a CAI dosage of 2%, the fresh SCC exhibits a slump of 260 mm and slump flow of 720 mm, indicating excellent filling and gap-passing abilities. Meanwhile, the compressive strengths at 3 d, 7 d, and 28 d remain at a high level. After 120 sulfate wet-dry cycles, the strength loss rate is only 8.4%, with an erosion resistance coefficient exceeding 90%. In addition, the resistance to chloride ion penetration is significantly improved, with an electric flux of only 1331 C, which is considerably lower than that of the control group (1637 C). At the optimal dosage of CAI, the concrete exhibits a dense and uniform internal structure devoid of macroscopic defects or cracks, with minimized porosity, thus synergistically enhancing the resistance to sulfate attack and chloride attack. On the contrary, further increasing the CAI dosage markedly intensifies the inhibitory effect of organic components on cement hydration, leading to increased early-age defects and enhanced pore connectivity. Thus, an appropriate amount of CAI can effectively improve the overall performance of SCC, providing a solid experimental basis and theoretical support for its engineering application in harsh corrosive environments. Full article

Background/Objectives: Nasal septal deviation (NSD) is a common anatomical condition that may influence nasal airflow and has been proposed as a potential factor associated with craniofacial growth and morphology. However, available studies use heterogeneous classifications and measurement methods, including the Mladina classification, angular parameters, volumetric assessment, CT, CBCT, and cephalometric analyses. This scoping review aimed to map and synthesize the available evidence on the relationship between NSD classifications, including the Mladina system, and craniofacial morphological correlates. Methods: This scoping review was conducted according to Joanna Briggs Institute methodology for scoping reviews and reported in accordance with the PRISMA-ScR checklist. The protocol was prospectively registered in the Open Science Framework. A broad literature search was performed in PubMed, Embase, Cochrane Library, BASE, and Google Scholar, without restrictions on publication date or language. Eligible studies included clinical or academic investigations assessing NSD using a defined classification or quantitative parameters and relating it to craniofacial, maxillary, mandibular, dentofacial, or asymmetry-related outcomes. Results: From 715 identified records, 387 remained after deduplication, and 6 studies met the inclusion criteria. The included studies varied substantially in sample size, imaging modality, NSD assessment method, and outcome domains. The most consistent findings suggested associations between NSD and localized or transverse nasomaxillary changes, particularly involving the palate, maxilla, nasal floor, and dentoalveolar region. Evidence regarding global facial asymmetry, basic maxillomandibular dimensions, and malocclusion was limited and inconsistent. Studies using the Mladina classification did not provide uniform conclusions across outcome domains. Conclusions: Current evidence does not support NSD as a uniform marker of global craniofacial morphology abnormalities. NSD appears more plausibly associated with selected local and transverse nasomaxillary features than with overall facial asymmetry. Future studies should combine standardized NSD classifications, especially the Mladina system, with precise three-dimensional craniofacial assessment in homogeneous populations. Full article

Reservoir effectiveness in marine shales is controlled not only by pore volume but also by pore-fluid occurrence, pore–throat connectivity, and mineral–organic matter coupling. In this study, the Permian Gufeng Formation shales from the Enshi area, western Hubei, South China, were investigated through an integrated analysis of total organic carbon (TOC), X-ray diffraction (XRD)-based mineral composition and lithofacies, low-field nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), micro-computed tomography (Micro-CT), and entropy-weighted technique for order preference by similarity to an ideal solution (TOPSIS) evaluation. The TOC content ranges from 1.60% to 21.38% and shows clear vertical differentiation, with moderate but variable enrichment in the lower interval, reduced organic matter abundance in the middle interval, and pronounced organic enrichment in the upper interval. Mineral compositions demonstrate an upward transition from a mixed siliceous–carbonate system to a dominantly siliceous shale system. NMR results reveal strong heterogeneity in porosity, NMR-derived permeability, T2cutoff, bound-fluid saturation, and free-fluid saturation. Based on saturated and centrifuged T2 spectra, four descriptive reservoir response types were identified: short-T2-dominated micropore-bound response, intermediate-T2-dominated movable-fluid response, long-T2-enriched but low-efficiency response, and NMR-inferred enhanced mobility composite response. SEM observations show diverse pore types, including organic-matter-related pores, dissolution pores, interparticle pores, mineral-edge pores, pyrite intercrystalline pores, and local microfracture-like pores. Micro-CT results indicate that micrometer-scale pore bodies are commonly isolated, demonstrating that pore abundance or pore size alone cannot determine reservoir effectiveness. TOC mainly controls pore generation potential, whereas siliceous minerals, pore–throat connectivity, movable fluid proportion, and local fractures exert stronger controls on effective reservoir development. The most favorable reservoir responses are concentrated in the upper high-organic siliceous shale interval from A33 to A42, with local enhanced responses in A16 and A21. These results provide an integrated framework for evaluating reservoir heterogeneity and favorable intervals in complex marine shale systems. Full article

Objectives: To evaluate the diagnostic performance of automated vertebral trabecular Hounsfield unit (HU) measurements derived from routine fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) for identifying low bone density. Methods: This retrospective study included 131 consecutive women (mean age, 53.5 ± 9.6 years) undergoing health screening with FDG PET/CT and dual-energy X-ray absorptiometry (DXA) between January 2020 and December 2024. A deep learning-based model (TotalSegmentator) automatically segmented the lumbar vertebrae (L1–L4). HU-based metrics in trabecular regions were calculated, and their correlations with DXA-derived bone mineral density (BMD) were assessed. Diagnostic performance was evaluated using receiver operating characteristic analysis. A multivariable logistic regression model incorporating mean HU, age, and body mass index was developed and internally validated using bootstrap resampling. Results: According to WHO criteria, 47 of 131 participants (35.9%) had low bone density. Mean HU demonstrated strong diagnostic performance (area under the curve [95% confidence interval]: L1, 0.861 [0.800–0.923]; L2, 0.852 [0.788–0.915]; L3, 0.861 [0.800–0.921]; L4, 0.845 [0.781–0.909]). L1 mean HU provided the most balanced performance (sensitivity, 0.851; specificity, 0.750); L3 mean HU was slightly inferior. L1 mean HU was strongly correlated with BMD (r = 0.821, p < 0.001). In multivariable analysis, mean HU independently predicted low bone density (odds ratio: 0.949, p < 0.001). The model achieved an accuracy of 0.786 and demonstrated favorable calibration performance. Conclusions: The automated assessment of vertebral trabecular HU from routine FDG PET/CT provides a reliable and highly efficient method for screening low bone density without additional radiation exposure or cost. Full article