Effect of cooking process on the structure and composition of cladodes (Opuntia ficus-indica).

High-frequency rTMS applied to the right hemisphere promotes aphasia recovery and brain microstructural changes in subacute stroke.

Moisture- and temperature-induced changes in microstructure and stabilization products remain a concern, requiring further study to clarify their effects on the engineering behavior of stabilized soils. Thus, this study aims to evaluate the engineering response of stabilized high-plasticity clay to moisture- and temperature-driven environmental conditioning, using hydrated lime (L) and lime sludge (S) under four sequences: freezing-thawing (FT), wetting-drying (WD), freezing-thawing-wetting-drying (FTWD), and wetting-drying-freezing-thawing (WDFT). Expansive soils were treated with a total dosage of 8% of L and S mixtures (4L4S and 6L2S) and evaluated through UCS and repeated load triaxial tests, further supported by microstructural and mineralogical analyses. Both 4L4S- and 6L2S-treated specimens exhibited improved engineering performance compared to the untreated soil due to short-term strength gains and long-term pozzolanic reactions. Importantly, the addition of lime sludge, a calcite-rich material, did not hinder the stabilization process, as 4L4S specimens achieved UCS values comparable to those of specimens treated with 5% hydrated lime. Both the treated specimens retained their integrity throughout the environmental conditioning phases, whereas the untreated specimens collapsed during the early stages. Among these durability studies, FT caused the most severe deterioration, due to substantial soil swelling during freezing. In contrast, coupled durability conditions caused relatively less damage, due to limited ice lens formation post drying phase, resulting in better engineering properties. Microstructural and mineralogical analyses were performed, which revealed the formation of cementitious gels, binding soil particles and enhancing the structural stability and durability of the treated specimens. Also, key variations in the mineral content, and related microstructure of the stabilized soils through thermogravimetric analysis were observed after different environmental conditionings. This explains the influence of the mineral contents and microstructure of stabilized soils on the long-term performance. • The effectiveness of lime sludge as partial replacement to hydrated lime for stabilizing expansive clays is established. • Different impacts of the coupled and uncoupled environmental durability cycles are investigated. • Microstructural and mineralogical investigations revealed the influence of environmental stressors on the long-term performance. • Need for the appropriate choice of durability protocols is recommended.

The strength of dual-phase α+α' Ti-6Al-4V sheet material can be significantly enhanced through additional short-time annealing lasting only a few minutes, as shown in previous work and attributed to nano-scale microstructural changes within the martensitically transformed β-phase. However, the microstructural mechanisms remained unclear. In this study, the microstructures of the as-received state, the solution heat treated state with α+α' microstructure and additionally (short-time) annealed states were compared to provide deeper insight into these microstructural processes. Advanced high-resolution techniques, including high resolution scanning transmission electron microscopy, atom probe tomography and high-energy X-ray diffraction, were combined with tensile testing for mechanical assessment. Short-time annealing of metastable Ti-6Al-4V α+α' microstructures at 570 °C for 180 s triggered an α' → α+β transformation, comprising: (i) chemical changes, involving V- and Fe-segregation to interfaces, and the formation of V-/Fe-enriched clusters; and (ii) crystallographic decomposition, manifested by α' lattice relaxation and lattice parameter changes. With prolonged annealing, element partitioning and β precipitation progressed from the clusters and nuclei located along interfaces, accompanied by slight changes in the lattice parameters of both phases. After 3 h, the microstructure approached equilibrium, with stabilized α and β phase fractions and lattice parameters. The strengthening achieved by short-time annealing is attributed to suppression of reorientation-induced plasticity in prior α'-martensite and dislocation-cluster/precipitate/solute interactions. In summary, this work reveals microstructural evolution and processes during martensite decomposition in dual-phase Ti-6Al-4V, including β-stabilizer segregation to interfaces. Further, it discusses their role in strength enhancement, providing guidance for developing effective heat treatment and processing routes.

Active protective coatings have been used and studied for decades. It is well known that the coating composition and microstructure determine the leaching behavior of the corrosion inhibiting species from the coating matrix. However, the leaching process on the microscale is a complex phenomenon important details of which remain obscured till today. Non-destructive spatial observation of the leaching process by nano-computed tomography using synchrotron radiation can contribute to a deeper understanding. Here, we report on the first truly in-situ 3D observation of microscale leaching. 3D images were generated while individual inhibitor particles dissolve from the coating matrix due to exposure to flowing water. The development and growth of pores and pore clusters was observed with a sequence of 3D images as a function of time demonstrating that leaching progresses by successive dissolution of inter-connected soluble particles. • First ever in-situ 3D observation of microstructural changes due to leaching. • 3D image sequence, obtained non-destructively, allows to track gradual changes in space and time. • Pores are observed to appear, merge, and form networks. • Measurements reveal pore network bottlenecks of widths 1-2 μ m. • Results strongly support the hypothesis that pore networks are the dominant way of ion transport.

This study delves into the effects of different mix parameters pertaining to the alkaline activator on the corrosion behavior of rebars and the microstructure evolution of fly ash–based geopolymer concrete (Fa-GpeC) when exposed to chloride ions, which play a crucial role in evaluating durability. The corrosion behavior of rebars was assessed by measuring the corrosion potential (Cpo) and corrosion current density (Icorr). In addition, microstructural changes were examined using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and field emission scanning electron microscopy (FESEM) techniques. The findings reveal that in the presence of chloride ions, at different ages, although the variations in Cpo (corrosion potential) and Icorr of rebars in GpeC were mostly unsystematic with changes in NaOH molarity, there was a noticeable increase in the extent of corrosion at higher-alkaline solution and at higher sodium silicate–sodium hydroxide (SS/SH) ratios. The GpeC made with lower-molarity NaOH solution exhibited higher free chloride content (Cf) content near the rebar at 600 days when compared with higher-molarity NaOH solutions. The GpeC mixes made with lower-alkaline solution exhibited higher free chloride (Cf), total chloride (Ct), and bound chloride (Cb) content than those made with higher-alkaline solution content. The Fa-GpeC made with lower-alkaline solution and having a lower SS/SH ratio mostly showed higher peak intensity for geopolymeric compounds in the XRD patterns. The variations in the formation of microstructure as observed from the FESEM images of GpeC near rebar level in prismatic specimens with alkaline solution, SS/SH ratio, and admixed NaCl concentration align with the changes in peak intensity of geopolymer gel–related compounds in the XRD patterns of the GpeC mixes.

Understanding real-time water penetration dynamics in tablets using synchrotron X-ray micro-computed tomography.

Microstructural changes in multilayer TiAlN cathodic arc evaporation coatings during milling of titanium α+β alloys

Physical properties of alloys are known to be affected by local order on the atomic scale; however, since this structural feature appears on sub-nanometer to nanometer scale, characterization of it is inherently challenging. Interest in local order in metallic systems has increased in recent years, driven by the development of increasingly compositionally complex alloys and observation of phenomena that cannot be explained by microstructural changes alone. One way to study local order is through the total scattering technique, an extension of powder diffraction where Bragg scattering and diffuse scattering are analyzed, often primarily through the pair distribution function. The calculation of a pair distribution function assumes an ideal powder with randomly oriented crystallites (i.e., without texture), which is rarely the case for conventionally processed engineering materials. Texture has numerically been shown to affect an arbitrary pair distribution function, but the effect has not been explored in depth across different alloy systems. In this work, we investigate the effect of texture on pair distribution functions for typical engineering materials through simulations, validate the simulation results with experimental data, and investigate potential artificial short-range order effects that may arise in large box models when texture is present. We show that different types of texture introduce perturbations in real space, which in turn affect model fitting within the Reverse Monte Carlo modelling framework. Based on this work, we conclude that samples for which the presence of texture cannot be excluded, through experimental setup or data reduction methods, are not suitable for standard PDF analysis.

Alumina (Al₂O₃) is a promising tritium-permeation and corrosion barrier and a functional ceramic for flow-channel inserts in PbLi-cooled fusion blankets. Here we compare the helium-implantation response of a commercial polycrystalline α-Al₂O₃ bulk material and a pulsed-laser-deposited (PLD) Al₂O₃ coating on EUROFER; the coating is additionally characterised after static Pb 17Li exposure at 550 °C to assess its chemical stability. Helium implantation was carried out in a SIMS workstation on electron-transparent FIB lamellae extracted from both materials, enabling transversal irradiation across the lamella thickness and direct before/after comparison of the same specimen. Implantation doses were derived from neutronic calculations for a DCLL breeding blanket and microstructural changes were analysed by TEM/STEM. In α-Al₂O₃, bubbles and cavities preferentially decorate grain boundaries and, in some grains, the grain interior, with a strong dependence on crystallographic orientation and diffraction condition. In the PLD coating, Pb 17Li exposure produces a thin near-surface modified (Li-enriched) layer (~50 nm), while the underlying coating remains dense and nanoceramic. After He implantation, cavities are mainly confined to the modified layer, whereas only isolated cavities are observed in the underlying coating within the analysed lamellae. Orientation-dependent threshold displacement energies ( E d ) from ab-initio calculations, combined with IRAD simulations, provide a framework to interpret the heterogeneous damage in α-Al₂O₃, whereas the nanoceramic coating behaves effectively isotropically at the nanodomain scale. • PLD amorphous Al₂O₃ on EUROFER is compared with polycrystalline α-Al₂O₃ under fusion-relevant Pb 17Li and He conditions. • He implantation is performed directly on FIB TEM lamellae using a SIMS workstation as a low-energy ion implanter. • Polycrystalline α-Al₂O₃ shows grain-boundary bubble decoration and strong orientation-dependent damage, rationalized via anisotropic E d and IRAD bounds. • The PLD-derived alumina confines cavities mainly to a Li-enriched surface layer after Pb 17Li exposure, with limited damage in the underlying nanoceramic region. • Dense amorphous/nanocrystalline alumina coatings with low grain-boundary connectivity provide a more uniform damage accommodation pathway than coarse-grained alumina.

Enzymatic modification of pumpkin and groundnut seed proteins for enhanced digestibility: BCAA-enriched peptide profiling and structural-functional characterization.

White matter alterations in right-onset versus left-onset Parkinson's disease in an early stage.

Origin of indentation size effect of hardness in Bulk Metallic Glasses

This study examines the microstructural changes in copper single-turn coils (STC) subjected to intense magnetic pressure during field generation. Three coil types were analyzed: “raw coils” (undeformed reference), “intermediate field coils” (subjected to non-destructive magnetic fields), and “maximum field coils” (destroyed during high-field generation). Vickers microhardness measurements across conductor cross-sections revealed significant local variations ranging from softening to work hardening (∼135 HV0.1) depending on the position and magnetic exposure. The results exhibit good agreement between local microhardness measurements and simulated thermal-mechanical conditions, highlighting the interplay between softening effects due to exposure to high temperatures (∼2500 K) and work hardening due to extreme magnetic pressures (∼10 GPa) occurring on microsecond timescale.

Fabrication and physicochemical characterization of SPI-gallic acid-guar gum ternary complexes: Insights into covalent bonding and structural tunability.

We explored the microwave drying of rubber tree (Hevea brasiliensis) wood using a multifaceted approach that encompasses various aspects. The primary objective was to examine drying behavior, drying time, moisture distribution across the core and surface, and to evaluate drying stresses via the prong test. Static bending and compression parallel to the grain were tested to assess the impact of microwave treatments on mechanical properties. The drying process showed a nearly uniform moisture distribution within the wood’s core and on its surface, indicating well-controlled drying. Most notably, the dried wood had no observable drying-induced stresses, suggesting a promising application of microwave drying. However, the volumetric shrinkage (%) was higher in microwave-dried samples (5.65% and 6.51%) than in air-dried samples (4.16%). A reduction in modulus of elasticity (MOE), modulus of rupture (MOR), and maximum compressive strength (MCS) was observed in the microwave-dried wood. Compared to the air-dried samples, the maximum reductions recorded were 15% for MOE, 18% for MOR, and 15% for MCS. The examination under light microscopy showed that the wood microstructures, such as ray cells and vessel walls, had incurred damage. The diminished mechanical properties could likely be linked to these micro-cracks or damage in the microstructures. The results show that these microstructural changes may significantly increase wood’s permeability. We also attempted to calculate the energy consumption for different microwave treatments. These findings emphasize the need for a balanced approach to optimizing microwave drying methods to mitigate reductions in mechanical properties while capitalizing on the advantages of reduced drying time and controlled, uniform moisture distribution.

Assessment of white matter integrity is critical for predicting functional recovery after ischemic stroke. However, conventional magnetic resonance imaging (MRI) cannot capture tract-specific microstructural changes, and diffusion tensor imaging (DTI) is limited by prolonged acquisition times. This study aimed to synthesize fractional anisotropy (FA) maps from routinely acquired T1-weighted (T1) MRI using 2.5D inputs within a generative adversarial network (GAN) framework. Specifically, our primary objective was to evaluate the relative efficacy of a proposed transfer learning strategy compared to single-domain training approaches. T1-FA paired data from 375 cognitively normal participants (832 images) from the Alzheimer's Disease Neuroimaging Initiative served as the non-lesion dataset, while longitudinal MRI data from 69 ischemic stroke patients (236 images) were from a single-center cohort. Three models were evaluated: the non-lesion-trained (NLT) model trained on non-lesion data, the lesion-trained (LT) model trained on stroke data, and the NLT model further fine-tuned on the stroke dataset (NLT + LF). Model performance was evaluated using voxel-wise errors (mean absolute error (MAE) and root mean square error (RMSE)), structural similarity (peak signal-to-noise ratio (PSNR) and structural similarity index measure (SSIM)), spatial overlap (Dice coefficient (Dice)), and distributional similarity (Kullback-Leibler divergence). Bonferroni-corrected paired t-tests showed that NLT + LF showed significantly better performance than NLT across all evaluated regions, including the whole brain, white matter, and lesions (all p < 0.001). Compared with LT, NLT + LF showed superior performance for all metrics at p < 0.001, except for lesion-region Dice and RMSE, which remained significant at p < 0.01. The preservation of lesion-relevant features and anatomical fidelity, together with the capture of degeneration patterns, accompanied these gains. Overall, the proposed NLT + LF approach improved lesion-specific representation and established that high-fidelity FA maps can be reliably synthesized from T1 MRI. This transfer learning framework offers a practical alternative to DTI for clinical stroke assessment.

This study aimed to investigate brain microstructural alterations in children with basic-type intermittent exotropia (IXT) using mean apparent propagator magnetic resonance imaging (MAP-MRI) and to analyze their correlations with clinical signs. MRI was performed on individuals with basic-type IXT and healthy controls using a 3T Siemens scanner with a 64-channel head coil. Three-dimensional T1-weighted and diffusion-weighted images were acquired. MAP-MRI parametric maps were reconstructed using the Laplace-constrained algorithm, with diffusion tensor imaging maps serving as a reference. Voxel-wise analysis and deterministic fiber tractography were conducted to investigate microstructural changes of cortical regions and visual pathway in basic-type IXT. Receiver operating characteristic analysis was performed to assess the discriminative performance of the MAP-MRI metrics. The correlations between MAP-MRI metrics in significant brain regions and clinical signs were also analyzed. Seventy-eight individuals with basic-type IXT and 96 healthy controls were enrolled. MAP-MRI revealed extensive microstructural alterations in brain regions associated with binocular vision and oculomotor control, as well as cognition and emotion regulation (P < 0.01 at both the voxel and cluster levels). Receiver operating characteristic analysis demonstrated that MAP-MRI metrics exhibited excellent discriminative performance, with the highest area under the curve of 0.986. In addition, MAP-MRI metrics were correlated with disease severity and disease duration (P < 0.05). MAP-MRI identified widespread microstructural alterations and their associations with clinical signs, providing valuable insights into the neural correlates underlying impaired binocular vision and oculomotor control in children with basic-type IXT. MAP-MRI metrics have the potential to serve as noninvasive imaging biomarkers for detecting IXT-related microstructural changes.

Iron fuel is a promising high‐energy density energy carrier. Using recycled iron‐rich sources, such as Direct Reduced Iron (DRI) ores, is of strong economic interest considering the added costs from purifying iron, but the influence of oxidized additions (Si, Al, Mn oxides) on the combustion process has hardly been investigated. In this study, the combustion products of DRI powder is compared to that of pure Fe in an open propane flame. The microstructure and chemical changes are characterized at different scales using a combination of SEM‐EDS and STEM‐EDS. Pore formation in combusted DRI and pure Fe powders is compared using X‐ray computed tomography (CT), BET surface area and gas pycnometer measurements, together with laser diffraction and image analysis granulometry. The role of oxygen gas release on the pore formation and the major modifications brought by the presence of Si are unveiled for the first time by a combination of experimental characterization and thermodynamic simulations. Crucially, our findings show that DRI is a viable source of Fe fuel. This paves the way for more sustainable and economically competitive high‐energy‐density carriers.

The performance and operational lifespan of aircraft engines are critical factors influencing flight safety and economic viability. Traditional methods for predicting aircraft engine service life often overlook microstructural changes, resulting in inaccurate predictions. To address this, a deep learning approach combining the Bidirectional Gated Recurrent Unit (BiGRU) model and self-Attention Mechanism (AM) for more accurate and reliable predictions is proposed. The method constructs a Health Index (HI) curve using a stacked denoising autoencoder and Kernel Canonical Correlation Analysis (KCCA), integrating self-AM for improved pattern recognition. The results were compared with the Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) methods, showing superior efficiency and accuracy. The integrated BiGRU method demonstrates rapid fitness reduction, superior computational speed, and consistent prediction accuracy across various prediction horizons. The overall findings suggest that this method holds significant promise for enhancing the prediction accuracy of aircraft engine combustion chambers' Remaining Useful Life (RUL), with potential applications in aviation engine maintenance and control protocols. Further optimization and testing under extreme conditions are warranted for future research.