Search Results (352)

Cement-based materials are essential construction components, yet their complex microstructures critically govern mechanical performance and durability. This study investigates the micro-textural characteristics and mechanical properties of cement paste modified with grinding aids (triethanolamine, TEA; maleic acid triethanolamine ester, MGA) and polycarboxylate-based superplasticizer (PCA). Moving beyond qualitative SEM limitations, we employ advanced image-based quantitative techniques: grayscale-based texture analysis for statistical evaluation and fractal dimension analysis for geometric quantification of microstructural irregularity. Results demonstrate that grinding aids enhance particle dispersion and reduce agglomeration, resulting in a more uniform micro-texture characterized by lower grayscale variability and reduced fractal dimensions. PCA superplasticizers further significantly enhance fluidity and compressive strength. The optimal formulation (MGA + PCA) achieved a 20% increase in 28-day compressive strength compared to control samples. The fractal dimension D_B exhibits a positive correlation with compressive strength, while energy and correlation values show a negative correlation; in contrast, entropy and contrast values demonstrate a positive correlation. This research advances quantitative microstructure characterization in cementitious materials, offering insights for tailored additive formulations to enhance sustainability and efficiency in concrete production. Full article

The Ti-6242 titanium alloy samples were forged at 1020 °C (slightly above the β-transus) and subjected to ultra-short isothermal holding (0–320 s) prior to quenching to investigate the rapid microstructural evolution in the parent β phase. Electron backscatter diffraction (EBSD) with parent β-phase reconstruction reveals that within only 1–3 s of holding, a pronounced <111> fiber texture develops along the forging axis, superseding the original <100> deformation fiber. This ultrafast texture change is attributed to metadynamic recrystallization (MDRX)—the post-deformation growth of nuclei formed during dynamic deformation. The newly formed <111>-oriented β grains still contain residual substructure, indicating incomplete strain release consistent with MDRX. Longer holds (tens of seconds) lead to more extensive static recrystallization and normal grain growth, which dilute the strong <111> fiber as grains of other orientations form and coarsen. These findings demonstrate that even a brief pause after forging can markedly alter the prior β texture via a MDRX mechanism. This insight highlights a novel approach to microtexture control in Ti-6242: by leveraging MDRX during short holds, one can potentially disrupt the formation of aligned α colony microtextured regions (MTRs, or “macrozones”) upon subsequent cooling, thereby mitigating dwell-fatigue susceptibility. The study revises the interpretation of the recrystallization mechanism in short-term holds and provides guidance for optimizing β-phase processing to improve fatigue performance. Full article

Multiple ironstone beds formed during the Callovian-Oxfordian times as a consequence of intense continental weathering, upwelling, and hydrothermal activity. This study examines the compositional differences between core and rim, and the origin of iron ooids along the northwestern margin of the Neo-Tethys Ocean to highlight sea-level fluctuations, redox conditions, and elemental influx. An integrated sedimentological study, including petrography, mineralogy, micro-texture, and mineral chemistry, was carried out to explain the origin and implications of ironstones. The ~14 m thick Callovian-Oxfordian, marginal marine deposits in the Kutch Basin, in western India, exhibit iron ooids, predominantly formed in oolitic shoals during transgression, associated with lagoonal siliciclastics. Callovian shoals interbedded with lagoonal facies record minor sea-level fluctuations, whereas the Oxfordian deposit records a major transgression and condensation, resulting in extensive ironstone deposits. The ooid cortices and nuclei exhibit distinctive mineralogy and micro-textures: glauconitic smectite exhibits poorly-developed rosettes, chamosite displays flower-like, and goethite shows rod-like features. Three types of ooids are formed: (i) monomineralic ooids are entirely of chamosite or goethite, (ii) quartz-nucleated ooids, and (iii) composite ooids with either chamosite core and goethite rim, or chamosite core and glauconitic smectite rim. The assemblages within iron ooids reflect variation in depositional redox conditions: glauconitic smectite develops under suboxic lagoonal flank, chamosite forms in anoxic central lagoon, and goethite precipitates on oxic shoals. Full article

Microtextured cutting tools are widely used because of their excellent performance in cutting difficult-to-machine materials. The cutting performance of cutting tools largely depends on the size parameters of the microtextures used. This study focuses on the machining of titanium alloy Ti-6Al4 V using microgrooved cutting tools under dry-cutting conditions. Special emphasis is placed on exploring cutting performance under specific combinations of microgroove parameters. To determine the optimal parameter combination for cutting, the effects of different microgroove parameters (including the diameter, depth, spacing, and spacing between grooves and cutting edges) on cutting force, tool wear, and chip morphology were investigated. In this study, femtosecond laser technology was used to prepare microgroove-textured cutting tools with different parameters, and the cutting performance of these tools was analyzed. The results show that, when the groove diameter is 80 μm, the depth is 60 μm, the spacing is 80 μm, and the distance between the groove and the tool tip is 120 μm, the cutting performance of the tool is optimal: the cutting force is reduced by 13.9%, the degree of tool wear is minimized, and the degree of chip curling is more uniform. The research results can be applied to the actual processing of Ti-6Al4 V, which can help tool design, selection, and microtexture parameter optimization. Full article

Friction contact regulation has been widely acknowledged, yet research on micro-textured meshing interfaces appears to have reached an impasse. Conventional wisdom holds that the similarity of micro-element configurations is the key factor contributing to textured interface issues. The traditional perception is transcended, and a novel method for presetting the optimal parameters of gradientized micro-textured interface elements is proposed. The study has analyzed the Interface Enriched Lubrication (IEL) performance and meshing Anti-Scuffing Load-Bearing Capacity (ASLBC) of periodic symmetrical and continuously gradient micro-elements. By actively regulating IEL behavior through geometric constraint effects, dynamic micro-cavity lubrication storage units are formed, thereby extending the retention time of medium film layers. The textured edges induce micro-vortices, delaying scuffing failures induced by load-bearing. Validation analyses demonstrate that optimal micro-element configurations can distribute contact stress to achieve stress homogenization, with the maximum contact stress reduced by 21%. The localized hydrodynamic effect of micro-textured elements increases interfacial meshing stiffness by 5.32% while decreasing friction torque by 27.3%. This investigation reveals a synergistic mechanism between IEL performance and meshing ASLBC under heavy loads conditions. The findings confirm that gradient-based micro-textured element configuration presetting offers an effective solution to reconcile the inherent trade-off between lubrication and load-bearing performance in heavy loads applications. Full article

Implantable biomaterials are widely used in modern medicine, especially in orthopaedics, cardiovascular surgery, dentistry, and plastic and reconstructive surgery. The issue of the interaction of implants with body tissues and the risk of infection associated with them is one of the most studied and topical issues in medicine. It is very important to find a biomaterial that effectively combines both microbiology and tissue compatibility aspects. The aim of this research work was to determine the adhesion and colonization rates of Staphylococcus epidermidis, Pseudomonas aeruginosa, and Candida albicans on smooth, microtextured, and macro-textured silicone biomaterials in an in vitro study. A total of 90 silicone biomaterial samples were used, 30 for each type of biomaterial. In each of the biomaterial groups, half of the samples (n = 15) were used to determine the adhesion intensity and the other half to determine the colonization intensity on the active surface of the biomaterial samples. The study found that Staphylococcus epidermidis and Pseudomonas aeruginosa had the highest adhesion intensity on the macro-textured implant, while Candida albicans adhered best to smooth. Among the microorganisms, Pseudomonas aeruginosa demonstrated the highest colonization rate, followed by Staphylococcus epidermidis and then Candida albicans. The most intensive colonization of microorganisms was on the macro-textured implant, then on the micro-textured, and then on the smooth. The smooth and micro-textured implants did not show statistically significant differences in the intensity of adhesion and colonization. The biomaterials did not show pro-oxidant or anti-oxidant properties, and no lipid peroxidation was induced by the biomaterials. Full article

This study explores the fabrication of hydrophobic surfaces on polymer components via Digital Light Processing (DLP), with emphases on how texture geometry, feature dimensions, and resin type influence surface wettability. Square and cylindrical microtextures were fabricated and evaluated using static contact angle measurements. Square-shaped structures demonstrated enhanced hydrophobicity, with contact angles reaching 133.6°, compared to approximately 100° for cylindrical counterparts of identical dimensions. Increasing pillar height to 521 µm enhanced hydrophobicity by approximately 15%, while decreasing pillar spacing to 150 µm increased contact angles from 86.8° to 106°, highlighting the role of microstructure density. For square-shaped structures, the addition of a hydrophobic agent at 3 wt.% resulted in a contact angle of 123.4°, representing a 44% improvement over the untreated sample. These findings underscore the combined influence of resin chemistry, surface texture design, and dimensional parameters on wettability behavior. Although superhydrophobicity (contact angle > 150°) was not achieved, the study demonstrates notable advancements in optimizing hydrophobicity through DLP printing. Overall, the results support DLP as a scalable and cost-effective approach for engineering functional surfaces suited to self-cleaning, biomedical, and anti-fouling applications. Full article

A small, strongly schistose Ni-laterite occurrence at the Vermion ophiolite (40°26′ Ν, 22°10′ Ε), Northen Greece, along a strong shear zone, is characterized by relatively high Ni, Co and Mn contents, magnetite as the dominant mineral, garnet (grossularite), theophrastite [β-Ni(OH)₂], otwayite-like phase (ideally Ni₂CO₃(OH)₂.H₂O), (Ni, Co, Mn)-hydroxides, and Ni-phyllosilicates. New analytical data, including black-white and color back-scattered electron images (BSEIs), elemental mapping and scanning, and Raman Spectroscopy, alongside silicates and hydroxides revealed the presence of varying silica content (less than 1 to 29 wt.%) in theophrastite and in (Ni, Co, Mn ± Fe)-hydroxides, although the X-ray powder diffraction data correspond to those of pure hydroxides. The gradual stacking of fine fibrous otwayite-like crystals to the boundaries of successive thin layers and within layers themselves, results in porous mineral phases of varying density shifting towards more compact mineral with increasing residence time. The presented data suggest that a potential explanation of the presence of Si in theophrastite may be the precipitation of Si after initial Ni-hydroxyl-carbonate fine crystals deposition. A potential sequence of the stability of Ni-minerals at Vermion may be as follows: Hydroxyl-carbonates < [β-Ni(OH)₂] (theophrastite) < (Ni, Co, Mn)(OH)₂ < Ni-phyllosilicates; this may be a significant factor for Ni-exploration in Ni-larerite deposits. Full article

This study presents an advanced framework for fabric texture classification by leveraging macro- and micro-texture extraction techniques integrated with deep learning architectures. Co-occurrence histograms, local binary patterns (LBPs), and albedo-dependent feature maps were employed to comprehensively capture the surface properties of fabrics. A late fusion approach was applied using four state-of-the-art convolutional neural networks (CNNs): InceptionV3, ResNet50_V2, DenseNet, and VGG-19. Excellent results were obtained, with the ResNet50_V2 achieving a precision of 0.929, recall of 0.914, and F1 score of 0.913. Notably, the integration of multimodal inputs allowed the models to effectively distinguish challenging fabric types, such as cotton–polyester and satin–silk pairs, which exhibit overlapping texture characteristics. This research not only enhances the accuracy of textile classification but also provides a robust methodology for material analysis, with significant implications for industrial applications in fashion, quality control, and robotics. Full article

The Matra As–Sb deposit (Alpine Corsica, France) is hosted in the normal N–S trending Matra Fault. Sulfide minerals in ore consist of realgar, stibnite, and pyrite with minor orpiment and hörnesite. The gangue includes quartz, dolomite, and calcite. In this study, the microstructural analysis of selected ore samples has been combined with the geochemical characterization of the sulfides. The results depict a succession of events that record the evolution of the ore deposit related to fault movement. In the pre–ore stage, plumose, crustiform, jigsaw, and feathery textures of quartz testify to a short–lived boiling event. The mineral assemblage of the main–ore stage includes an Fe(–Zn) substage dominated by the formation of different textures of pyrite. In general, pyrite samples contain significant concentrations of As (≤32,231 ppm) and Sb (≤10,684 ppm), with lesser amounts of by Tl (≤1257 ppm) and Ni (≤174 ppm). This is followed by an Sb–As–Fe substage of pyrite–stibnite–realgar ±orpiment. The precipitation of the sulfides was mainly driven by changes in ƒS₂. The increasing level of oxidation is attributed to a progressive influx of meteoric water resulting from reactivation of the Matra Fault. Full article

As manufacturing demands for challenging-to-machine metallic materials continue to evolve, the performance of cutting tools has emerged as a critical limiting factor. The synergistic application of micro-texture and coating in cutting tools can improve various properties. For the processing of existing micro-texture, because of the fast cooling and heating processing method of laser, there are defects such as remelted layer stacking and micro-cracks on the surface after processing. This study introduces a preheating-assisted technology aimed at optimizing the milling performance of textured coated tools. A milling test platform was established to evaluate the performance of these tools on titanium alloys under thermally assisted conditions. The face-centered cubic response surface methodology, as part of the central composite design (CCD) experimental framework, was employed to investigate the interaction effects of micro-texture preparation parameters and thermal assistance temperature on milling performance. The findings indicate a significant correlation between thermal assistance temperature and tool milling performance, suggesting that an appropriately selected thermal assistance temperature can enhance both the milling efficiency of the tool and the surface quality of the titanium alloy. Utilizing the response surface methodology, a multi-objective optimization of the textured coating tool-preparation process was conducted, resulting in the following optimized parameters: laser power of 45 W, scanning speed of 1576 mm/s, the number of scans was 7, micro-texture spacing of 130 μm, micro-texture diameter of 30 μm, and a heat-assisted temperature of 675.15 K. Finally, the experimental platform of optimization results is built, which proves that the optimization results are accurate and reliable, and provides theoretical basis and technical support for the preparation process of textured coating tools. It is of great significance to realize high-precision and high-quality machining of difficult-to-machine materials such as titanium alloy. Full article

Micro-textures are crucial for enhancing surface performance in diverse applications, but traditional radial electrochemical micromachining (REMM) suffers from process complexity and workpiece damage. This study presents radial ultrasonic rolling electrochemical micromachining (RUREMM), an advanced technique integrating an ultrasonic field to improve electrolyte renewal, disrupt passivation layers, and optimize electrochemical reaction uniformity on SS304 surfaces. Aimed at overcoming challenges in precision machining, the research explores the synergistic effects of ultrasonic energy and flow field dynamics, offering novel insights for high-quality metal micromachining applications. The research establishes a mathematical model to analyze the interaction between the ultrasonic energy field and electrolytic machining and optimizes the flow field in the narrow electrolytic gap using Fluent software, revealing that an initial electrolyte velocity of 4 m/s and ultrasonic amplitude of 35 μm ensure optimal stability. High-speed photography is employed to capture bubble distribution and micro-pit formation dynamics, while SS304 surface experiments analyze the effects of machining parameters on micro-dimple localization and surface quality. The results show that optimized parameters significantly improve micro-texture quality, yielding micro-pits with a width of 223.4 μm, depth of 28.9 μm, aspect ratio of 0.129, and Ra of 0.205 μm, providing theoretical insights for high-precision metal micromachining. Full article

The vibration and noise of friction pairs are severe when cutting titanium alloy with cemented carbide tools, and the surface micro-texture can significantly reduce noise and friction. Therefore, it is very important to clarify the correlation mechanism between friction noise and friction force for processing quality control. Consequently, investigating the underlying mechanisms that link friction noise and friction is of considerable importance. This study focuses on the friction and wear acoustic signals generated by micro-textured cemented carbide–titanium alloy. A friction testing platform specifically designed for the micro-textured cemented carbide grinding of titanium alloy has been established. Acoustic sensors are employed to capture the acoustic signals, while ultra-depth-of-field microscopy and scanning electron microscopy are utilized for surface analysis. A novel approach utilizing the dung beetle algorithm (DBO) is proposed to optimize the parameters of variational mode decomposition (VMD), which is subsequently combined with wavelet packet threshold denoising (WPT) to enhance the quality of the original signal. Continuous wavelet transform (CWT) is applied for time–frequency analysis, facilitating a discussion on the underlying mechanisms of micro-texture. Additionally, features are extracted from the time domain, frequency domain, wavelet packet, and entropy. The Relief-F algorithm is employed to identify 19 significant features, leading to the development of a hybrid model that integrates Bayesian optimization (BO) and Transformer-LSTM for predicting friction. Experimental results indicate that the model achieves an R² value of 0.9835, a root mean square error (RMSE) of 0.2271, a mean absolute error (MAE) of 0.1880, and a mean bias error (MBE) of 0.1410 on the test dataset. The predictive performance and stability of this model are markedly superior to those of the BO-LSTM, LSTM–Attention, and CNN–LSTM–Attention models. This research presents a robust methodology for predicting friction in the context of friction and wear of cemented carbide–titanium alloys. Full article

Water-lubricated bearings (WLB), due to their pollution-free nature and low noise, are increasingly becoming critical components in aerospace, marine applications, high-speed railway transportation, precision machine tools, etc. However, in practice, water-lubricated bearings suffer severe friction and wear due to low-viscosity water, harsh conditions, and contaminants like sediment, which can compromise the lubricating film and shorten their lifespan. The implementation of micro-textures has been demonstrated to improve the tribological performance of water-lubricated bearings to a certain extent, leading to their widespread adoption for enhancing the frictional dynamics of sliding bearings. The shape, dimensions (including length, width, and depth), and distribution of these micro-textures have a significant influence on the frictional performance. Therefore, this study aims to explore the coupling effect of different micro-texture shapes and distributions on the frictional performance of water-lubricated sliding, using the computational fluid dynamics (CFD) analysis. The results indicate that strategically arranging textures across multiple regions can enhance the performance of the bearing. Specifically, placing linear groove textures in the outlet of the divergent zone and triangular textures in the divergent zone body maximize improvements in the load-carrying capacity and frictional performance. This specific configuration increases the load-carrying capacity by 7.3% and reduces the friction coefficient by 8.6%. Overall, this study provided critical theoretical and technical insights for the optimization of WLB, contributing to the advancement of clean energy technologies and the extension of critical bearing service life. Full article

Background/Objectives: The aim of this case series is to evaluate the outcomes and safety of video-assisted mastectomy, illustrating the harmonious collaboration of oncologic and plastic surgery. This novel minimally invasive technique allows immediate prosthetic reconstruction and represents a cost-effective alternative to robotic breast surgery. Methods: Video-assisted, single-port nipple-sparing mastectomies were performed in patients with small to medium-sized breasts, followed by immediate direct-to-implant reconstruction with either prepectoral or dual plane implant placement. The patients’ electronic medical records were analyzed, including demographic characteristics, operative times and histopathology reports. Results: A total of 18 patients underwent successful video-assisted mastectomy, without conversion to traditional open procedure. Fifteen of the operations were risk-reducing mastectomies. Twelve patients had complementary procedures performed concurrently on the previously operated contralateral breast (delayed reconstruction/expander-to-implant exchange). Moreover, three patients benefited from additional minimally invasive techniques during the same surgery (prophylactic laparoscopic hysterectomy). Immediate breast reconstruction with polyurethane or microtextured breast implants up to 450 cc was performed, with satisfactory aesthetic outcomes and no cancer recurrences at 6 to 12 months postoperative follow-up. Early complications included transient hypercapnia, areolar congestion and cellulitis. No skin necrosis or implant-related complications were reported. The most frequently encountered late issues were contour irregularities. Conclusions: Video-assisted mastectomy facilitates the safe removal of proven pathologic or healthy breast tissue with minimal damage to the breast’s skin envelope, facilitating single-stage breast reconstruction. Full article