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15 pages, 1248 KB  
Article
Multimodal Behavioral Sensors for Lie Detection: Integrating Visual, Auditory, and Generative Reasoning Cues
by Daniel Grabowski, Kamila Łuczaj and Khalid Saeed
Sensors 2025, 25(19), 6086; https://doi.org/10.3390/s25196086 - 2 Oct 2025
Viewed by 256
Abstract
Advances in multimodal artificial intelligence enable new sensor-inspired approaches to lie detection by combining behavioral perception with generative reasoning. This study presents a deception detection framework that integrates deep video and audio processing with large language models guided by chain-of-thought (CoT) prompting. We [...] Read more.
Advances in multimodal artificial intelligence enable new sensor-inspired approaches to lie detection by combining behavioral perception with generative reasoning. This study presents a deception detection framework that integrates deep video and audio processing with large language models guided by chain-of-thought (CoT) prompting. We interpret neural architectures such as ViViT (for video) and HuBERT (for speech) as digital behavioral sensors that extract implicit emotional and cognitive cues, including micro-expressions, vocal stress, and timing irregularities. We further incorporate a GPT-5-based prompt-level fusion approach for video–language–emotion alignment and zero-shot inference. This method jointly processes visual frames, textual transcripts, and emotion recognition outputs, enabling the system to generate interpretable deception hypotheses without any task-specific fine-tuning. Facial expressions are treated as high-resolution affective signals captured via visual sensors, while audio encodes prosodic markers of stress. Our experimental setup is based on the DOLOS dataset, which provides high-quality multimodal recordings of deceptive and truthful behavior. We also evaluate a continual learning setup that transfers emotional understanding to deception classification. Results indicate that multimodal fusion and CoT-based reasoning increase classification accuracy and interpretability. The proposed system bridges the gap between raw behavioral data and semantic inference, laying a foundation for AI-driven lie detection with interpretable sensor analogues. Full article
(This article belongs to the Special Issue Sensor-Based Behavioral Biometrics)
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20 pages, 10152 KB  
Article
In Vivo Comparison of Resin-Modified and Pure Calcium-Silicate Cements for Direct Pulp Capping
by Fatma Fenesha, Aonjittra Phanrungsuwan, Brian L. Foster, Anibal Diogenes and Sarah B. Peters
Appl. Sci. 2025, 15(19), 10639; https://doi.org/10.3390/app151910639 - 1 Oct 2025
Viewed by 370
Abstract
Introduction: Direct pulp capping (DPC) aims to preserve the vitality of the dental pulp by placing a protective biocompatible material over the exposed pulp tissue to facilitate healing. There are several calcium-silicate materials that have been designed to promote mineralization and the regulation [...] Read more.
Introduction: Direct pulp capping (DPC) aims to preserve the vitality of the dental pulp by placing a protective biocompatible material over the exposed pulp tissue to facilitate healing. There are several calcium-silicate materials that have been designed to promote mineralization and the regulation of inflammation. These have strong potential for the repair and regeneration of dental pulp. Among them, Biodentine (BD) and EndoSequence RRM Putty (ES) have been found to promote in vitro and in vivo mineralization while minimizing some of the limitations of the first-generation calcium-silicate-based materials. Theracal-LC (TLC), a light-cured, resin-modified calcium-silicate material, is a newer product with potential to improve the clinical outcomes of DPC, but existing studies have reported conflicting findings regarding its biocompatibility and ability to support pulpal healing in direct contact with the pulp. A comprehensive assessment of the biocompatibility and pulpal protection provided by these three capping materials has not yet been performed. Aim: We aimed to quantify the inflammatory response, dentin bridge formation, and material adaptation following DPC using three calcium-silicate materials: ES, BD, and TLC. Materials and Methods: DPC was performed on the maxillary first molar of C57BL/6 female mice. Maxilla were collected and processed at 1 and 21 days post-DPC. The early inflammatory response was measured 24 h post-procedure using confocal imaging of anti-Lys6G6C, which indicates the extent of neutrophil and monocyte infiltration. Reparative mineralized bridge formation was assessed at 21 days post-procedure using high-resolution micro-computed tomography (micro-CT) and histology. Lastly, the homogeneity of the capping materials was evaluated by quantifying voids in calcium-silicate restorations using micro-CT. Results: DPC using TLC induced less infiltration of Lys6G6C+ cells at 24 h than BD or ES. BD promoted higher volumes of tertiary dentin than TLC, but TLC and ES showed no significant differences in volume. No differences were observed in material adaptation and void spaces among the three capping materials. Conclusions: All three materials under investigation supported pulp healing and maintained marginal integrity. However, TLC induced a lower inflammatory response on day 1 and induced similar levels of tertiary dentin to ES. These observations challenge the common perception that resin-based capping materials are not suitable for direct pulp capping. Our findings underscore the need to balance biological responses with physical properties when selecting pulp capping materials to improve long-term clinical success. Full article
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30 pages, 1900 KB  
Review
The Life of MicroRNAs: Biogenesis, Function and Decay in Cancer
by Shuang Ding and Pingping Wang
Biomolecules 2025, 15(10), 1393; https://doi.org/10.3390/biom15101393 - 30 Sep 2025
Viewed by 414
Abstract
MicroRNAs (miRNAs) are small non-coding RNAs that play pivotal roles in post-transcriptional gene regulation, influencing development, differentiation, and disease pathogenesis. Since their discovery in 1993, miRNAs have been recognized for their evolutionary conservation and pleiotropic effects, with the 2024 Nobel Prize underscoring their [...] Read more.
MicroRNAs (miRNAs) are small non-coding RNAs that play pivotal roles in post-transcriptional gene regulation, influencing development, differentiation, and disease pathogenesis. Since their discovery in 1993, miRNAs have been recognized for their evolutionary conservation and pleiotropic effects, with the 2024 Nobel Prize underscoring their significance in post-transcriptional regulation via the RNA interference (RNAi) pathway. This review synthesizes the complete life cycle of miRNAs—from transcription and processing to function and decay—emphasizing regulatory mechanisms and their implications in human diseases, particularly cancer. We discuss how epitranscriptomic modifications influence miRNA biogenesis and activity, explore their nuclear and mitochondrial functions, and address emerging challenges in miRNA-based therapeutics, including the expanding small RNA landscape such as tRNA-derived small RNAs (tsRNAs), and Argonaute (AGO)-independent activities. Despite hurdles such as modest multi-target effects, off-target interactions, and delivery challenges, miRNAs remain promising as both biomarkers and therapeutic agents, underscoring the need for sustained research to bridge preclinical insights with clinical applications. Full article
(This article belongs to the Special Issue Molecular Signalling Pathways in Tumorigenesis and Tumor Suppression)
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15 pages, 270 KB  
Article
The Narrow Corridor of Heartfelt Leadership: Social and Emotional Leadership Practices in Bureaucratic School Cultures
by Sevgi Yıldız
Behav. Sci. 2025, 15(10), 1316; https://doi.org/10.3390/bs15101316 - 26 Sep 2025
Viewed by 300
Abstract
This qualitative study examines how school administrators enact “heartfelt leadership”—a socially and emotionally attuned form of leadership—within Türkiye’s bureaucratic school cultures. Using semi-structured interviews with six administrators and six teachers across primary, secondary, and high school, we employed a basic qualitative design with [...] Read more.
This qualitative study examines how school administrators enact “heartfelt leadership”—a socially and emotionally attuned form of leadership—within Türkiye’s bureaucratic school cultures. Using semi-structured interviews with six administrators and six teachers across primary, secondary, and high school, we employed a basic qualitative design with maximum-variation sampling. Thematic content analysis yielded four themes: (1) principals acknowledge the humanity of their teachers; (2) principals prioritize relationships and go beyond formal duties; (3) bureaucracy constrains but does not fully silence heartfelt leadership; and (4) heartfelt leadership fosters motivation, resilience, and retention. Heartfelt leadership was marked by empathy, recognition of significant moments, and proactive care that extends beyond job descriptions, cultivating trust, motivation, and commitment. Yet rigid procedures and centralized decision-making limited leaders’ autonomy and responsiveness. No consistent gender differences emerged among principals, because all participating teachers were female; therefore, cross-gender comparisons among teachers were not possible. Theoretically, the study bridges emotional-intelligence and bureaucratic-organization scholarship, showing how relational leadership can be sustained in centralized systems through micro-level strategies. Empirically, it broadens global leadership discourse by examining emotional leadership in a non-Western, bureaucratic context. Practically, findings suggest embedding social and emotional competencies in leadership preparation and enabling greater discretionary authority for responsive, human-centered school leadership. Full article
(This article belongs to the Special Issue Social and Emotional Learning in Schools)
25 pages, 686 KB  
Review
microRNA Biomarkers in Paediatric Infection Diagnostics—Bridging the Gap Between Evidence and Clinical Application: A Scoping Review
by Oenone Rodgers, Anna De Beer and Thomas Waterfield
Non-Coding RNA 2025, 11(5), 71; https://doi.org/10.3390/ncrna11050071 - 24 Sep 2025
Viewed by 266
Abstract
Background: Distinguishing between bacterial and viral infections in children remains a significant challenge for clinicians. Traditional biomarkers have limited utility, often leading to antibiotic overprescription due to clinician uncertainty. With rising antimicrobial resistance, novel biomarkers are needed to improve diagnosis. This scoping review [...] Read more.
Background: Distinguishing between bacterial and viral infections in children remains a significant challenge for clinicians. Traditional biomarkers have limited utility, often leading to antibiotic overprescription due to clinician uncertainty. With rising antimicrobial resistance, novel biomarkers are needed to improve diagnosis. This scoping review examines current host miRNA biomarkers for acute bacterial and viral infections in children (0–18), focusing on study methods, diagnostic metrics, and research gaps to support clinical translation. Results: Of the 1147 articles identified, 36 studies were included. Notably, 72.2% of the studies originated from Asia, and the distribution across the paediatric age groups was relatively even. A total of 17 miRNAs were validated in at least two independent studies. Three miRNAs, hsa-miR-182-5p, hsa-miR-363-3p, and hsa-miR-206, were consistently associated with bacterial infection in children. Meanwhile, nine miRNAs were associated with viral infections: hsa-miR-155, hsa-miR-29a-3p, hsa-miR-155-5p, hsa-miR-150-5p, hsa-miR-140-3p, hsa-miR-142-3p, hsa-miR-149-3p, hsa-miR-210-3p, and hsa-miR-34a-5p. Across the 12 studies reporting diagnostic accuracy metrics, miRNA biomarkers exhibited a sensitivity ranging from 70% to 100%, and a specificity ranging from 72% to 100%. The area under the curve across the studies demonstrated a range from 0.62 to 0.99. Conclusions: This scoping review highlights the potential of miRNA targets for diagnosing paediatric infections when studied rigorously. However, clinical translation is limited by poor adherence to STARD guidelines, lack of robust diagnostic metrics, and study heterogeneity. Many studies were set up with a case–control design, a design that, while highlighting differences, is more likely to identify non-specific biomarkers rather than those that are useful for novel clinical diagnostics. Full article
(This article belongs to the Section Detection and Biomarkers of Non-Coding RNA)
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31 pages, 6593 KB  
Article
Domain-Oriented Hierarchical Topology Optimisation—An Approach for Heterogeneous Materials
by João Dias-de-Oliveira, Joaquim Pinho-da-Cruz and Filipe Teixeira-Dias
Appl. Sci. 2025, 15(18), 10201; https://doi.org/10.3390/app151810201 - 18 Sep 2025
Viewed by 322
Abstract
In structural topology optimisation, intermediate densities are typically interpreted as local distributions of heterogeneous materials, bridging the gap between a solid and a void through optimised arrangements of cellular or composite microstructures. These multiscale configurations, governed by interactions between micro- and macroscales, are [...] Read more.
In structural topology optimisation, intermediate densities are typically interpreted as local distributions of heterogeneous materials, bridging the gap between a solid and a void through optimised arrangements of cellular or composite microstructures. These multiscale configurations, governed by interactions between micro- and macroscales, are commonly addressed via hierarchical approaches. However, such methods often suffer from high computational cost and limited practical applicability. This work proposes an alternative strategy that reformulates the hierarchical problem by replacing pointwise microscale variations with a subdomain-based formulation. Each subdomain is associated with a periodic microstructure, reducing the number of local problems and significantly decreasing computational demands. A multiscale topology optimisation framework is developed using Asymptotic Expansion Homogenisation, enabling effective macrostructural properties and supporting inverse homogenisation for microscale design. The proposed method is implemented in a user-developed code and validated through several benchmark problems. The results show that the subdomain approach yields discrete and manufacturable microstructures that better reflect real-world composite applications, while also achieving substantial improvements in computational efficiency. Full article
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30 pages, 983 KB  
Article
An Integrated DEA–Porter Decision Support Framework for Enhancing Supply Chain Competitiveness in the Muslim Fashion Industry: Evidence from Indonesia
by Jilly Ayuningtias, Marimin Marimin, Agus Buono and Arif Imam Suroso
Logistics 2025, 9(3), 129; https://doi.org/10.3390/logistics9030129 - 12 Sep 2025
Viewed by 805
Abstract
Background: The competitiveness of Indonesia’s Muslim fashion industry requires evaluation through both internal efficiency and external strategic factors, yet existing approaches often assess these dimensions separately. Methods: This study develops a Weighted Efficiency Competitive Score (WECS) that integrates Data Envelopment Analysis (DEA) to [...] Read more.
Background: The competitiveness of Indonesia’s Muslim fashion industry requires evaluation through both internal efficiency and external strategic factors, yet existing approaches often assess these dimensions separately. Methods: This study develops a Weighted Efficiency Competitive Score (WECS) that integrates Data Envelopment Analysis (DEA) to measure operational efficiency and Porter’s Five Forces to capture market pressures. The weights of α and β were calibrated through sensitivity analysis under the constraint α + β = 1, with values ranging from α = 0.3 to 0.7 and β = 0.7 to 0.3, using data from 23 Muslim fashion businesses in Jakarta. Results: The analysis identified α = 0.6 and β = 0.4 as the most stable configuration, and only 30% of firms achieved both high efficiency and strong market positioning. Strategic leaders such as JT. Co and PM. Co demonstrated that digital transformation, disciplined cost structures, and strong supply chain partnerships foster sustainable competitiveness. Conclusions: The WECS framework offers a replicable method to quantitatively integrate micro and macro determinants of competitiveness, contributes to the literature by bridging efficiency and strategy evaluation, and provides practical guidance for managers and policymakers to enhance decision support systems in strengthening the Muslim fashion industry’s global positioning. Full article
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17 pages, 10657 KB  
Article
Ultrashort Pulsed Laser Fabrication of High-Performance Polymer-Film-Based Moulds for Rapid Prototyping of Microfluidic Devices
by Pieter Daniël Haasbroek, Mischa Wälty, Michael Grob and Per Magnus Kristiansen
J. Manuf. Mater. Process. 2025, 9(9), 313; https://doi.org/10.3390/jmmp9090313 - 12 Sep 2025
Viewed by 586
Abstract
Microfluidic device prototyping demands rapid, cost-effective, and high-precision mould fabrication, yet ultrashort pulsed laser structuring of polymer inserts remains underexplored. This study presents a novel method for fabricating microfluidic mould inserts using femtosecond (fs) laser ablation of polyimide (PI) films, achieving high precision [...] Read more.
Microfluidic device prototyping demands rapid, cost-effective, and high-precision mould fabrication, yet ultrashort pulsed laser structuring of polymer inserts remains underexplored. This study presents a novel method for fabricating microfluidic mould inserts using femtosecond (fs) laser ablation of polyimide (PI) films, achieving high precision from design to prototype. PI films (250 µm) were structured using a 355 nm fs laser (300 fs, 500 kHz, 0.95 J/cm2) in a photochemically dominated ablation regime and bonded to reusable steel plates. Injection moulding trials with cyclic olefin copolymer (COC) and polymethyl methacrylate (PMMA) were conducted with diverse designs, including concentration gradient generators (CGG), organ-on-chip (OOC) with 20 µm bridges, and double emulsion droplet generators (DEDG) with 100–500 µm channels, ensuring robustness across complex geometries. The method achieved near 1:1 replication (errors < 2%, microchannel height tolerances < 1%, Sa = 0.02 µm in channels, 0.26 µm in laser-structured areas), machining times under 2 h, and mould durability over 100 cycles without significant deterioration. The PI’s heat-retarding effect mimicked variothermal moulding, ensuring complete micro-penetration without specialised equipment. By reducing material costs using PI films and reusable steel plates, enabling rapid iterations within hours, and supporting industry-compatible prototyping, this approach lowers barriers for small-scale labs. It enables rapid prototyping of diagnostic lab-on-chip devices and supports decentralised manufacturing for biomedical, chemical, and environmental applications, offering a versatile, cost-effective tool for early-stage development. Full article
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23 pages, 3668 KB  
Article
Graph-Driven Micro-Expression Rendering with Emotionally Diverse Expressions for Lifelike Digital Humans
by Lei Fang, Fan Yang, Yichen Lin, Jing Zhang and Mincheol Whang
Biomimetics 2025, 10(9), 587; https://doi.org/10.3390/biomimetics10090587 - 3 Sep 2025
Viewed by 645
Abstract
Micro-expressions, characterized by brief and subtle facial muscle movements, are essential for conveying nuanced emotions in digital humans, yet existing rendering techniques often produce rigid or emotionally monotonous animations due to the inadequate modeling of temporal dynamics and action unit interdependencies. This paper [...] Read more.
Micro-expressions, characterized by brief and subtle facial muscle movements, are essential for conveying nuanced emotions in digital humans, yet existing rendering techniques often produce rigid or emotionally monotonous animations due to the inadequate modeling of temporal dynamics and action unit interdependencies. This paper proposes a graph-driven framework for micro-expression rendering that generates emotionally diverse and lifelike expressions. We employ a 3D-ResNet-18 backbone network to perform joint spatio-temporal feature extraction from facial video sequences, enhancing sensitivity to transient motion cues. Action units (AUs) are modeled as nodes in a symmetric graph, with edge weights derived from empirical co-occurrence probabilities and processed via a graph convolutional network to capture structural dependencies and symmetric interactions. This symmetry is justified by the inherent bilateral nature of human facial anatomy, where AU relationships are based on co-occurrence and facial anatomy analysis (as per the FACS), which are typically undirected and symmetric. Human faces are symmetric, and such relationships align with the design of classic spectral GCNs for undirected graphs, assuming that adjacency matrices are symmetric to model non-directional co-occurrences effectively. Predicted AU activations and timestamps are interpolated into continuous motion curves using B-spline functions and mapped to skeletal controls within a real-time animation pipeline (Unreal Engine). Experiments on the CASME II dataset demonstrate superior performance, achieving an F1-score of 77.93% and an accuracy of 84.80% (k-fold cross-validation, k = 5), outperforming baselines in temporal segmentation. Subjective evaluations confirm that the rendered digital human exhibits improvements in perceptual clarity, naturalness, and realism. This approach bridges micro-expression recognition and high-fidelity facial animation, enabling more expressive virtual interactions through curve extraction from AU values and timestamps. Full article
(This article belongs to the Section Bioinspired Sensorics, Information Processing and Control)
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43 pages, 1021 KB  
Review
A Survey of Cross-Layer Security for Resource-Constrained IoT Devices
by Mamyr Altaibek, Aliya Issainova, Tolegen Aidynov, Daniyar Kuttymbek, Gulsipat Abisheva and Assel Nurusheva
Appl. Sci. 2025, 15(17), 9691; https://doi.org/10.3390/app15179691 - 3 Sep 2025
Viewed by 1055
Abstract
Low-power microcontrollers, wireless sensors, and embedded gateways form the backbone of many Internet of Things (IoT) deployments. However, their limited memory, constrained energy budgets, and lack of standardized firmware make them attractive targets for diverse attacks, including bootloader backdoors, hardcoded keys, unpatched CVE [...] Read more.
Low-power microcontrollers, wireless sensors, and embedded gateways form the backbone of many Internet of Things (IoT) deployments. However, their limited memory, constrained energy budgets, and lack of standardized firmware make them attractive targets for diverse attacks, including bootloader backdoors, hardcoded keys, unpatched CVE exploits, and code-reuse attacks, while traditional single-layer defenses are insufficient as they often assume abundant resources. This paper presents a Systematic Literature Review (SLR) conducted according to the PRISMA 2020 guidelines, covering 196 peer-reviewed studies on cross-layer security for resource-constrained IoT and Industrial IoT environments, and introduces a four-axis taxonomy—system level, algorithmic paradigm, data granularity, and hardware budget—to structure and compare prior work. At the firmware level, we analyze static analysis, symbolic execution, and machine learning-based binary similarity detection that operate without requiring source code or a full runtime; at the network and behavioral levels, we review lightweight and graph-based intrusion detection systems (IDS), including single-packet authorization, unsupervised anomaly detection, RF spectrum monitoring, and sensor–actuator anomaly analysis bridging cyber-physical security; and at the policy level, we survey identity management, micro-segmentation, and zero-trust enforcement mechanisms supported by blockchain-based authentication and programmable policy enforcement points (PEPs). Our review identifies current strengths, limitations, and open challenges—including scalable firmware reverse engineering, efficient cross-ISA symbolic learning, and practical spectrum anomaly detection under constrained computing environments—and by integrating diverse security layers within a unified taxonomy, this SLR highlights both the state-of-the-art and promising research directions for advancing IoT security. Full article
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32 pages, 11740 KB  
Article
Experimental and Analytical Study on Concrete Mechanical Properties of Recycled Carbon Fibers from Wind Turbine Blades
by Julita Krassowska
Materials 2025, 18(17), 4105; https://doi.org/10.3390/ma18174105 - 1 Sep 2025
Viewed by 803
Abstract
This study examines the effects of incorporating recycled carbon fibers obtained from decommissioned wind turbine blades into cementitious composites. An extensive experimental program was carried out, varying fiber content (0–8 kg/m3), fiber length (25, 38, 50 mm), water-to-cement ratio (0.4, 0.5), [...] Read more.
This study examines the effects of incorporating recycled carbon fibers obtained from decommissioned wind turbine blades into cementitious composites. An extensive experimental program was carried out, varying fiber content (0–8 kg/m3), fiber length (25, 38, 50 mm), water-to-cement ratio (0.4, 0.5), and cement type (CEM I 42.5, CEM II 42.5R/A-V). The mechanical properties of the fiber-reinforced concretes, including compressive strength, flexural strength, splitting tensile strength, and modulus of elasticity, were evaluated. The addition of recycled carbon fibers significantly improved flexural and splitting tensile strengths, with increases exceeding 60% and 100%, respectively, at the highest fiber dosage (8 kg/m3), attributed to efficient crack-bridging capability. Compressive strength was mainly influenced by the water-to-cement ratio, while the modulus of elasticity showed slight reductions in some mixes due to fiber clustering and increased micro-porosity. Regression analysis indicated that shorter fibers (25 mm) were more effective in enhancing flexural strength, whereas longer fibers (50 mm) improved splitting tensile strength. Classical predictive models generally underestimated the flexural capacity of recycled-carbon-fiber-reinforced concretes, highlighting the need for recalibration. Optical microscopy confirmed uniform fiber dispersion at lower dosages and a dominant pull-out failure mechanism. The findings demonstrate the feasibility of using recycled carbon fibers to enhance the mechanical performance of concrete while supporting sustainability through waste diversion and circular economy strategies. Full article
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25 pages, 9854 KB  
Article
Numerical Analysis on Mechanical Properties of Different Fiber-Reinforced Cold-Formed Steel–Concrete Composite Corner Columns
by Mengyao Li, Yi Hu, Lanzhe Rao, Liqiang Jiang, Jingbin Li, Shizhong Zhou, Hongyu Sun, Shi Peng, Xia Pang, Yuanjun Chen, Jun Hu and Ping Xie
Polymers 2025, 17(17), 2365; https://doi.org/10.3390/polym17172365 - 30 Aug 2025
Viewed by 706
Abstract
To overcome brittle failure in conventional cold-formed steel–concrete (CFS-C) corner columns, this paper used fiber-reinforced concrete to replace ordinary concrete, investigating failure mechanisms and performance through systematic numerical simulations. A finite element model (FEM) was established and validated by experiments, and the errors [...] Read more.
To overcome brittle failure in conventional cold-formed steel–concrete (CFS-C) corner columns, this paper used fiber-reinforced concrete to replace ordinary concrete, investigating failure mechanisms and performance through systematic numerical simulations. A finite element model (FEM) was established and validated by experiments, and the errors for ultimate capacity were within 10%. A series of numerical models was established for parametric analyses focusing on the effects of the parameters of polypropylene fiber (PF), carbon fiber (CF), steel fiber (SF), and bamboo fiber (BF) with different volume dosages and the thickness of cold-formed steel (CFS) on the axial compression ultimate capacity and corresponding displacement of CFS composite corner columns. The results indicated that (1) PF effectiveness was dependent on steel thickness: thicker steel suppressed micro-defects, activated the toughening potential of PF, and increased the ultimate capacity of the columns by 24.8%. (2) CF had a critical dosage of 0.4%: at this dosage, CF increased the column’s ultimate capacity by 14.1% through stress redistribution, while when the dosage exceeded this value, fiber agglomeration caused a reduction in the column’s strength, with a maximum decrease of 16.2%. (3) SF effectiveness showed a linear increase: at a dosage of 1.6%, SF formed a synergistic three-dimensional bridging network and generated a confinement effect, increasing the column’s ultimate capacity by 36.5% and displacement by 92.2%. (4) BF mainly improved the ductility of columns: through crack bridging and pull-out energy dissipation, BF increased column displacement by 33.2%. (5) The modified Eurocode 4 formula could reduce the calculation error of ultimate capacity from 6.3% to within 1%. The findings guide optimal fiber selection and dosage in practice, promoting such columns’ use in seismic and load-bearing structures. Full article
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23 pages, 4458 KB  
Article
Ultrasonic Pulp Conditioning-Induced Nanoparticles: A Critical Driver for Sonication-Assisted Ultrafine Smithsonite Flotation
by Weiguang Zhou, Weiwei Cao, Chenwei Li, Yaoli Peng, Yanru Cui and Liuyang Dong
Minerals 2025, 15(9), 927; https://doi.org/10.3390/min15090927 - 30 Aug 2025
Viewed by 492
Abstract
Extensive studies have established that ultrasonic micro-jets and acoustic cavitation selectively intensify interfacial interactions at multiphase boundaries, thereby enhancing the flotation of soluble salt minerals and oxide ores. Although a growing body of evidence shows that pulp-borne nanoparticles (i.e., nanosolids, colloids, and nanoscale [...] Read more.
Extensive studies have established that ultrasonic micro-jets and acoustic cavitation selectively intensify interfacial interactions at multiphase boundaries, thereby enhancing the flotation of soluble salt minerals and oxide ores. Although a growing body of evidence shows that pulp-borne nanoparticles (i.e., nanosolids, colloids, and nanoscale gas nuclei) mediate these effects, their role in the flotation of ultrafine smithsonite after collector addition has not yet been systematically examined. To fill this gap, we compared the flotation response of ultrafine smithsonite under conventional stirring (SC) and ultrasonic conditioning (UC), using sodium oleate (NaOL) as the collector, and dissected the governing mechanisms across three pillars, mineral–NaOL interaction, particle aggregation, and frothability, with particular attention paid to how nanoparticles modulate each dimension. The flotation results show that flotation performance under UC is dictated by NaOL concentration. At low NaOL levels (i.e., below 4 × 10−4 M), UC depresses both recovery and kinetics relative to SC, while at high NaOL levels, the trend reverses and UC outperforms SC. Mechanistic analysis reveals that sonication erodes mineral surfaces and generates cavitation, flooding the pulp with various nanoparticles. When NaOL is scarce, zinc-containing components and zinc-rich nanosolids sequester the collector through non-selective adsorption and precipitation, leaving smithsonite poorly hydrophobized. Consequently, particle aggregation and pulp frothability are markedly inferior to those in the SC system, so the flotation recovery and kinetics remain lower. As the NaOL concentration rises, smithsonite becomes adequately hydrophobized, and the pulp fills with hydrophobic zinc-rich nanosolids, along with cavitation-induced gas nuclei or tiny bubbles. These nanoparticles now act as bridges, accelerating the aggregation of ultrafine smithsonite once sonication stops and agitation begins, while simultaneously improving frothability. Although the strong dispersive action of ultrasound still suppresses initial flotation kinetics, cumulative recovery ultimately surpasses that of SC. The findings delineate a nanoparticle-regulated flotation paradigm and establish a critical NaOL concentration window for effective UC in ultrafine smithsonite flotation. This framework is readily transferable to the beneficiation of other ultrafine, soluble oxidized minerals (rhodochrosite, dolomite, etc.). Full article
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21 pages, 7226 KB  
Article
Machine Learning-Enhanced Nanoindentation for Characterizing Micromechanical Properties and Mineral Control Mechanisms of Conglomerate
by Yong Guo, Wenbo Zhang, Pengfei Li, Yuxuan Zhao, Zongjie Mu and Zhehua Yang
Appl. Sci. 2025, 15(17), 9541; https://doi.org/10.3390/app15179541 - 29 Aug 2025
Viewed by 444
Abstract
Conglomerate reservoirs present significant technical challenges during drilling operations due to their complex mineral composition and heterogeneous characteristics, yet the quantitative relationships between mineral composition and microscopic mechanical behavior remain poorly understood. To elucidate the variation patterns of conglomerate micromechanical properties and their [...] Read more.
Conglomerate reservoirs present significant technical challenges during drilling operations due to their complex mineral composition and heterogeneous characteristics, yet the quantitative relationships between mineral composition and microscopic mechanical behavior remain poorly understood. To elucidate the variation patterns of conglomerate micromechanical properties and their mineralogical control mechanisms, this study develops a novel multi-scale characterization methodology. This approach uniquely couples nanoindentation technology, micro-zone X-ray diffraction analysis, and machine learning algorithms to systematically investigate micromechanical properties of conglomerate samples from different regions. Hierarchical clustering algorithms successfully classified conglomerate micro-regions into three lithofacies categories with distinct mechanical differences: hard (elastic modulus: 81.90 GPa, hardness: 7.83 GPa), medium-hard (elastic modulus: 54.97 GPa, hardness: 3.87 GPa), and soft lithofacies (elastic modulus: 25.21 GPa, hardness: 1.15 GPa). Correlation analysis reveals that quartz (SiO2) content shows significant positive correlation with elastic modulus (r = 0.52) and hardness (r = 0.51), while clay minerals (r = −0.37) and plagioclase content (r = −0.48) exhibit negative correlations with elastic modulus. Mineral phase spatial distribution patterns control the heterogeneous characteristics of conglomerate micromechanical properties. Additionally, a random forest regression model successfully predicts mineral content based on hardness and elastic modulus measurements with high accuracy. These findings bridge the gap between microscopic mineral properties and macroscopic drilling performance, enabling real-time formation strength assessment and providing scientific foundation for optimizing drilling strategies in heterogeneous conglomerate formations. Full article
(This article belongs to the Section Energy Science and Technology)
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15 pages, 2330 KB  
Article
The Influence of Moisture Content and Workmanship Accuracy on the Thermal Properties of a Single-Layer Wall Made of Autoclaved Aerated Concrete (AAC)
by Maria Wesołowska and Daniel Liczkowski
Materials 2025, 18(17), 3967; https://doi.org/10.3390/ma18173967 - 25 Aug 2025
Viewed by 742
Abstract
The use of single-layer aerated concrete walls in residential construction has a tradition of over 60 years. Its main advantage is thermal insulation. It is the most advantageous among construction materials used for the construction of external walls. The possibility of modifying the [...] Read more.
The use of single-layer aerated concrete walls in residential construction has a tradition of over 60 years. Its main advantage is thermal insulation. It is the most advantageous among construction materials used for the construction of external walls. The possibility of modifying the dimensions of the blocks leads to meeting subsequent restrictive values of the heat transfer coefficient U. The high dimensional accuracy of the blocks allows the use of dry vertical joints and thin joints with a thickness of 1–3 mm, the thermal influence of which is omitted. However, the thermal uniformity of such a wall is strictly dependent on the quality of workmanship. The main objective of the analysis is to assess the impact of moisture on the Uwall of walls as a function of vertical joint spacing and horizontal joint thickness. It should be said that the effect of humidity and manufacturing accuracy on the thermal properties of aerated concrete walls has not been sufficiently studied. Further study of these patterns is necessary. Particular attention should be paid to the thin-bed mortar, which depends on the manufacturing accuracy. The separation of AAC masonry elements that occurs during bricklaying significantly affects the thermal insulation of walls. This issue has not yet been analysed. The scientific objective of this article is to develop a procedure for determining the thermal properties of a small, irregular air space created as a result of the separation of masonry elements and the impact of this separation on the thermal insulation of the wall. Based on the analysis of the thermal conductivity of voids and masonry elements, it was determined that this impact is visible at low AAC densities. A detailed analysis taking into account both these joints and horizontal joints, as well as different moisture levels, made it possible to determine the permissible separation of AAC blocks, at which the high thermal insulation requirements applicable in most European countries are met. The analysis showed that it is possible to meet the thermal protection requirements for 42 cm wide blocks intended for single-layer walls with a maximum vertical contact width of 3 mm and a joint thickness of up to 2 mm. AAC moisture content plays a major role in thermal insulation. Insulation requirements can be met for AAC in an air-dry state, as specified by ISO 10456. Full article
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