Search Results (17,033)

The reuse of the finest fraction derived from recycled aggregate washing has been investigated for the manufacture of mortars. This practice contributes to the circular economy and lowers CO₂ emissions in the manufacturing of construction materials. A distinction was made between concrete-rich residues (RH) and mixed concrete–ceramic wastes (RHM). Chemical and mineralogical analyses of samples collected over a two-year period revealed consistent homogeneity over time. The RH residues are richer in CaO, primarily as calcite. Conversely, higher ceramic content in the waste correlates with increased SiO₂, Al₂O₃, and K₂O concentrations, predominantly as phyllosilicates and feldspars. Ettringite and portlandite occur in trace amounts. DTA-TG analysis reveals the presence of minor contents of portlandite and C-S-H gel. Mortars were prepared by replacing 10%, 20%, and 30% of Portland cement (OPC) with concrete-derived (RH) and mixed concrete–ceramic (RHM) wastes. At 10% and 20% substitution, both wastes yielded similar strengths, confirming their high potential for masonry mortars without prior treatment. However, at 30% replacement, RH provided markedly higher compressive and flexural strengths than RHM, likely due to a greater presence of the C-S-H gel phase in concrete waste. While 10% and 20% replacements successfully meet the 70% Strength Activity Index (SAI) threshold, a 30% limit severely reduces strength. Consequently, substitutions of 30% or higher require mechanical or thermal activation to enhance CDW reactivity. Given the minimal performance gap between RH and RHM, processing mixed CDW streams uniformly is recommended to maximize economic viability and ensure batch homogeneity in industrial washing plants. Full article

Functionally graded lattice structures (FGLSs) have emerged as a promising class of architected materials that enable spatial control of mechanical, thermal, and biological properties through variations in geometry, topology, material composition, and density. Advances in additive manufacturing (AM) have significantly expanded the design and fabrication capabilities of FGLSs for applications in aerospace, biomedical, energy, and transportation sectors. This review presents a comprehensive assessment of FGLSs through a process–structure–property (P–S–P) perspective, highlighting the influence of AM processes, manufacturing defects, and microstructural evolution on structural performance. A unified six-axis taxonomy (topology family, graded variable, gradient-field description, scale level, process and material route, target metric) is proposed for cross-study comparison. Five architecture families are examined: strut-based, triply periodic minimal surface (TPMS), stochastic, plate-based, and mechanism-driven or hierarchical lattices, together with density, material, topology, and hybrid grading approaches. Recent advances in computational modeling, topology optimization, artificial intelligence (AI), and machine learning are discussed, emphasizing their role in accelerating design, property prediction, and inverse engineering. Finally, key challenges and future opportunities related to digital twins, autonomous manufacturing, multi-material systems, and qualification of FGLSs are identified. This review provides a structured framework for the development of next-generation AI-enabled FGLSs with enhanced multifunctional performance and manufacturability. Full article

Integration of composites into the fabrication process of structural assemblies within the aerospace, automotive, marine or civil engineering industries represents a rational solution adopted by leading companies which are guided by the necessity for novel low-weight, high-strength, and high-stiffness materials. During the manufacturing process and throughout the service life, fiber-reinforced polymer structures are subjected to impact loading, either accidentally or as an inherent requirement of the operational cycle. Firstly, general aspects regarding impact loading and some parameters used for its characterization are briefly described. Recent progress regarding the influence of the stacking sequence, fiber type, and impactor geometry on the impact performance of Kevlar and glass fiber reinforced composite materials is emphasized. Additionally, the effects of environmental factors (such as temperature, UV radiation, or humidity) on the impact energy absorbed by polymers reinforced with each of the two types of synthetic fibers are presented. Finally, the importance of directing the researcher’s judgment towards improving the characteristics of materials subjected to impact, from a sustainable perspective, is motivated through the presentation of the impact behavior of polymer composites reinforced with Kevlar fibers or glass fibers hybridized with vegetable fibers. Full article

Artificial intelligence (AI) may influence economic performance through productivity, innovation, and the diffusion of advanced technologies, but direct country-level measures of AI adoption remain limited for small economies. This study examines the association between AI-related technological capability and economic growth in Cyprus. The descriptive analysis covers 1993–2024, while the econometric analysis uses the common annual sample for 2008–2024 after introducing one-period lags. High-technology exports as a percentage of manufactured exports are treated as an indirect indicator of technological sophistication and absorptive capacity, rather than as a direct measure of AI adoption. A sequential distributed lag ordinary least squares framework introduces current and lagged high-technology exports, merchandise trade, and inflation, with heteroskedasticity-consistent HC3 standard errors. A COVID-19 indicator for 2020–2021 and an observation-exclusion sensitivity analysis are used to assess the influence of exceptional pandemic-era movements. The preferred specification explains a substantial share of annual GDP growth variation, but the small sample requires cautious interpretation. The estimates indicate a positive contemporaneous and a negative lagged association for high-technology exports, a stronger lagged than contemporaneous trade association, and opposite-signed current and lagged inflation coefficients. The COVID-19 indicator is statistically insignificant and does not materially alter the principal coefficient pattern. Complementary DESI, Eurostat enterprise AI use, and ICT employment indicators show that Cyprus has broadly adequate digital inputs while enterprise AI adoption has not yet reached the European Union average, indicating considerable scope for further diffusion. The findings are exploratory statistical associations and do not identify causal effects of AI. The study contributes a country-specific macroeconomic assessment of technological capability, digital readiness, and growth in a small, highly open economy. Full article

Background and Objectives: Periodontal health represents a condition characterized by homeostasis between the teeth and the surrounding supporting tissues and implies the absence of inflammation, confirmed by the lack of bleeding, epithelial attachment loss, mobility, or periodontal pocket formation. Fixed prosthetic restorations may compromise periodontal health already during the fabrication phase, given that decisions made during their planning and placement affect long-term clinical outcomes. The aim of this manuscript was to provide insight into the interaction between periodontal tissues and fixed prosthetic restorations. Materials and Methods: A narrative literature review was conducted using a structured search of the PubMed/MEDLINE, Scopus, and Google Scholar databases to identify studies addressing periodontal health in relation to fixed dental prostheses. The impacts of tooth preparation, gingival retraction methods, supracrestal tissue attachment, periodontal phenotype, crown emergence profile, and marginal fit of various biomaterials were analyzed. Results: According to the literature data, subgingival margin placement and violation of the supracrestal tissue attachment (biological width) induce chronic inflammation, loss of epithelial attachment, and alveolar bone resorption. Gingival retraction agents, used in chemomechanical retraction procedures, particularly ferric sulfate-based agents, may lead to a transient but significant spike in inflammatory markers and dysbiosis of the subgingival microbiome. Contemporary approaches, such as the biologically oriented preparation technique and the use of CAD/CAM (Computer-Aided Design and Computer-Aided Manufacturing) technology, may improve the precision of marginal fit. Zirconia restorations exhibit significantly better biocompatibility and reduced microbial adhesion compared to metal–ceramic restorations. Conclusions: Biological response of the periodontium to fixed prosthetic restorations depends on the complex interaction between the material, position of the marginal line, and oral hygiene control. Regardless of the material used or the fabrication technique employed, adequate plaque control and regular maintenance remain key factors in preserving periodontal health. Full article

Hydrogel fibers provide a one-dimensional platform for constructing soft robotic materials that combine tissue-like compliance, high water content, structural anisotropy, and stimulus responsiveness. Compared with bulk hydrogels, their reduced radial dimensions shorten mass-transport pathways, while programmable fiber architectures convert otherwise isotropic swelling or contraction into directional deformation. This review summarizes the recent progress in anisotropic hydrogel fibers for soft robotics, with emphasis on the relationships among fabrication strategies, fiber architectures, actuation mechanisms, and robotic functions. Representative architectures, including Janus, bilayer, core–sheath, hollow, helically twisted, gradient, axially patterned, woven, and printed systems, are discussed in terms of their strain-conversion mechanisms, structural advantages, limitations, and suitable applications. Major fabrication approaches and stimulus-responsive mechanisms are further compared with respect to structural programmability, response kinetics, mechanical output, cyclic stability, scalability, and device integration. Particular attention is given to architecture selection, long-term environmental stability, interference from secondary stimuli, and the transition from laboratory demonstrations to practical soft robotic systems. Finally, key design principles and future directions are outlined for developing faster, more durable, manufacturable, and autonomous hydrogel-fiber-based soft robots. Full article

Meat and meat products are highly susceptible to microbial spoilage, lipid oxidation, moisture loss, discoloration, and sensory deterioration, creating a need for effective, safe, and sustainable packaging solutions. Although previous studies have investigated biodegradable polymers, nanomaterials, and active packaging systems separately, an integrated assessment connecting material design, preservation mechanisms, safety, sustainability, and commercial feasibility remains limited. This review addresses this gap by critically evaluating recent advances in biodegradable nanocomposite films and coatings for meat preservation. Current evidence demonstrates that the incorporation of nanoscale reinforcements and bioactive agents into biopolymer matrices can enhance their mechanical performance, gas and moisture barrier properties, antimicrobial activity, antioxidant capacity, and controlled release behavior. However, these advantages are strongly influenced by the nanofiller characteristics, concentration, dispersion, polymer-nanofiller interactions, food matrix composition, and storage conditions. Excessive nanomaterial incorporation may promote aggregation, induce structural defects, reduce flexibility, and increase migration concerns. Despite promising preservation outcomes, most available studies remain limited to laboratory-scale investigations, variable testing protocols, and insufficient validation under real commercial conditions. Key challenges hindering industrial adoption include nanoparticle migration, long-term safety assessment, regulatory uncertainty, production costs, consumer acceptance, and limited life-cycle evaluation. Future research should focus on safe-by-design formulations, standardized real-food testing, scalable manufacturing approaches, controlled-release technologies, and integrated assessments of preservation efficiency, safety, economic feasibility, and environmental sustainability. Overall, biodegradable nanocomposite packaging represents a promising approach for extending meat shelf life; however, successful commercialization requires balancing enhanced preservation performance with safety assurance and industrial practicality. Full article

The accurate determination of the thickness of the metallic coating on steel substrates is essential in industrial quality control. Eddy current testing offers a non-destructive solution by evaluating the impedance or mutual impedance of one or multiple coils. Analytical models exist in the literature for selected sensor configurations. Building on these models, a model-based estimation approach can be applied to derive an estimate for coating thickness and other relevant material and geometry parameters. Conventional setups typically employ wire-wound coils. However, manufacturing tolerances introduce discrepancies between nominal and actual coil geometries, which lead to deviations in the coating thickness estimate. A printed circuit board (PCB)-based coil with lithographically defined geometry achieves substantially tighter fabrication tolerances and higher repeatability than wire-wound coils. In this work, an analytical mutual impedance model for a differential multi-layer PCB pancake coil is derived and validated against established models in the literature with respect to forward modeling accuracy and model-based parameter estimation performance. Furthermore, experimental measurements with two-layer and eight-layer PCB differential coil systems produce parameter estimates with significantly better reproducibility than wire-wound coils. The experimental results show that the two-layer PCB coil achieves close agreement between the absolute estimated parameters and the reference values without requiring additional calibration, while maintaining high sensitivity to coating thickness. Full article

This research directly addresses three critical global challenges, construction waste generation, forced displacement and housing shortage, through the design and development of a regenerative, modular housing system utilizing biodegradable composite materials synthesized from locally abundant agricultural waste, specifically rice straw. Bio-based panels were manufactured and used together with Casuarina Glauca wood to fabricate sandwich panels to be used as roofs and walls. Four configurations of the sandwich panels were manufactured and tested to select the strongest of them to be used within the proposed structure. Through systematic material testing, structural analysis, and lifecycle environmental assessment, this work demonstrates that locally sourced agricultural waste can form the foundation of dignified, low-carbon temporary shelters with minimal environmental impact at end-of-life when compared with conventional reinforced-concrete construction. The 3 m × 3 m bio-based shelter, designed for complete disassembly and reuse, achieves 88% lower embodied carbon than its conventional reinforced-concrete counterpart while maintaining adequate structural performance for temporary housing applications. Furthermore, the designed shelter has a cost that is 64% lower than that of its conventional reinforced-concrete counterpart and 40% lower than that of a refugee housing unit. Full article

Detection of nanoplastics in drinking-water systems is only the first analytical step toward exposure interpretation; the next challenge is source attribution. This review examines molecular fingerprinting and transformation pathways that can link nanoscale polymer signals to source waters, drinking-water treatment, distribution infrastructure, packaging materials, laboratory background, or aging processes across the potable-water chain. Nanoplastics are treated here as operationally defined particles below 1 µm, including intentionally manufactured primary nanoplastics and secondary nanoplastics generated by fragmentation, abrasion, weathering, treatment, storage, or packaging stress. The synthesis evaluates how polymer identity, particle morphology, surface oxidation, additive and oligomer profiles, thermal degradation markers, matrix context, and quality assurance/quality control (QA/QC) can be combined into defensible source assignments. Analytical platforms considered include surface-enhanced Raman spectroscopy (SERS), atomic force microscopy–infrared spectroscopy (AFM-IR), optical photothermal infrared spectroscopy (O-PTIR), stimulated Raman scattering microscopy (SRS), pyrolysis–gas chromatography–mass spectrometry (Py-GC/MS), asymmetric flow field-flow fractionation coupled to Py-GC/MS (AF4-Py-GC/MS), matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS), and chemometric workflows. The central conclusion is that source attribution cannot be inferred from polymer identity alone; robust interpretation requires convergent evidence from particle-level chemistry, polymer-specific mass, additive or marker-ion signatures, aging state, blanks, recovery, and contextual sampling design. Full article

Designing products that feel simple and intuitive while remaining efficient to manufacture and meaningful across cultures remains a key challenge in contemporary product development. Although minimalist design has achieved commercial success, most methodologies fail to systematically connect aesthetic intentions with engineering, usability, and production realities. This study proposes a four-phase iterative framework—Framing, Translation, Materialisation, and Experience that integrates human-centred design, simplicity heuristics—including ‘SHE’ (Shrink, Hide, Embody) tactics, quantitative aesthetic measurement, Design for X methods, and cross-cultural considerations to operationalise minimalist principles such as formal reduction, seriality, and industrial materiality. An empirical case study applied the framework to three competing automotive interior concepts through image-based evaluation by 113 respondents. Results provided preliminary evidence that a balanced hybrid approach consistently outperformed both traditional button-heavy and extreme single-screen minimalist designs across measures of usability, sense of order, trust, and user recommendation. Findings confirm that effective minimalism does not merely remove elements but strategically redistributes complexity into interface logic, production systems, and material quality. The framework offers designers a structured yet flexible path to create manufacturable, user-validated, and culturally sensitive minimalist products. Full article

Mechanical (or structural) metamaterials offer a paradigm shift in the mechanical response of advanced structures, achieving performance distinct from their base material through architected unit cells that geometrically tailor stress distribution. Characterising these structures demands methodologies capable of capturing localised deformations while reconciling numerical predictions with as-manufactured behaviour. This study introduces a Digital Image Correlation (DIC) based methodology for the mechanical characterisation of three two-dimensional PLA lattice metamaterials, produced by material extrusion (MEX) and selected from a computational screening of approximately 57,000 candidate geometries to span the negative, zero and positive Poisson’s ratio regimes. Predicted and measured Poisson’s ratios agreed to within 0.01 across all three geometries without correction, whereas structural rigidity deviated substantially from nominal geometry predictions. A targeted correction strategy, using micro-computed tomography (µCT) to measure wall thickness at high-stress concentration zones identified through finite element modelling, reduced these deviations from 46% to 7% for the auxetic geometry, and from 25% to 2% for the positive Poisson geometry. These results show that Poisson’s ratio and rigidity respond differently to manufacturing-induced dimensional deviation, and that efficient, targeted geometric correction, rather than full model reconstruction, is sufficient to reconcile numerical and experimental behaviour for these structures. This approach offers a practical framework for the experimental evaluation and numerical validation of mechanical metamaterials. Full article

Dimensional accuracy and surface roughness in material extrusion (MEX) have been widely studied; however, the effect of part scale on the simultaneous fulfilment of geometrical tolerances and surface finish remains less clearly established. This study evaluates the scale-dependent quality of PLA parts manufactured by material extrusion (MEX) using a full 3 × 3 × 3 factorial design, combining three scales (1×, 0.75×, and 0.5×), three commercial PLA filaments, and three printing speeds (40, 60, and 80 mm/s). A dedicated test artefact was inspected by a coordinate measuring machine to quantify GD&T-related deviations, including flatness, perpendicularity, parallelism, angularity, circularity, cylindricity, and coaxiality. Surface roughness was characterized by 2D profilometry using Ra, Rz, and Rq on representative horizontal and vertical surfaces. Results showed that part scale was the dominant factor affecting geometrical conformity, especially for orientation- and location-related tolerances such as perpendicularity, parallelism, and coaxiality, which deteriorated markedly as specimen size decreased. Filament type also influenced several geometrical responses, whereas printing speed showed no significant main effect on geometrical tolerances within the evaluated range. Surface roughness exhibited clear anisotropy, with vertical surfaces showing higher values and stronger statistical dependence on process factors. Unlike studies focused only on dimensional accuracy or surface roughness, this work provides an integrated GD&T-based and surface-texture assessment of scale-dependent quality loss in PLA parts manufactured by MEX. These findings may help designers and manufacturers define inspection criteria, select suitable commercial PLA filaments, and identify critical geometrical features when scaled MEX parts are intended for functional applications. Full article

High-entropy alloys (HEAs) offer attractive combinations of mechanical performance, thermal stability, and compositional flexibility, making them promising candidates for advanced structural applications. Laser-based additive manufacturing, particularly laser powder bed fusion (LPBF) and laser-directed energy deposition (LDED), enables the fabrication of geometrically complex HEA components with non-equilibrium microstructures. However, the distinct thermal histories of LPBF and LDED, with typical cooling rates of approximately 10⁵–10⁷ K s⁻¹ and 10²–10⁴ K s⁻¹, respectively, strongly govern solidification behavior, elemental segregation, residual stress development, defect formation, and mechanical properties. Although previous reviews have discussed additively manufactured HEAs, an integrated framework linking composition design, printability, LPBF/LDED processing, microstructural evolution, post-processing, and industrial qualification remains limited. Therefore, this review establishes a unified composition–process–structure–property framework for laser additively manufactured HEAs. Fundamental HEA concepts, LPBF/LDED process characteristics, solidification behavior, phase formation, defect evolution, and mechanical performance from ambient to elevated temperatures are systematically discussed across representative FCC, refractory, and dual-phase HEA systems. This review emphasizes that printability should be considered during alloy design by correlating composition-dependent solidification characteristics, cracking susceptibility, phase stability, and defect formation with mechanical performance. Post-processing treatments are shown to modify residual stress, microsegregation, precipitation behavior, porosity, and deformation mechanisms, although their benefits must be balanced against thermal softening or brittle phase formation. Finally, CALPHAD, integrated computational materials engineering (ICME), machine learning (ML), and in situ monitoring are identified as promising tools for accelerating alloy and process optimization, while reproducible process windows, defect-control criteria, databases, and qualification protocols remain essential for industrial implementation. Full article

Pharyngeal infection with high-risk human papillomavirus (HPV), particularly HPV16, is biologically distinct from cervical infection because it occurs within the specialized lymphoepithelial environment of Waldeyer’s ring. This review evaluates nanoparticle materials for the prevention, detection, and treatment of pharyngeal HPV, with an emphasis on structure–property–function relationships, mucosal performance, and translational feasibility. Lipid nanoparticle platforms, polymeric nanoparticle platforms, inorganic systems, and hybrid platforms are compared with respect to composition, particle size distribution, surface charge, colloidal stability, biodegradability, payload compatibility, release behavior, and manufacturing complexity. Evidence suggests that lipid and polymeric systems are the most credible near-future candidates for mucosal vaccination and localized nucleic acid delivery because they offer the best balance between controllable fabrication, analytical tractability, and biologically plausible performance in mucus-exposed tissue. By contrast, the development of inorganic theranostics and CRISPR-enabled platforms remains at an earlier stage because repeated mucosal dosing, retention in lymphoid tissue, and combined product regulation impose substantial burdens. A translational roadmap is proposed in which material selection is guided by clinically relevant quality attributes, standardized saliva- and mucus-relevant assays, human tonsil organoid testing, and early attention to manufacturability, safety, and regulatory strategy. The field is promising, but direct pharyngeal HPV data remain limited; accordingly, there is an urgent need for comparative studies that connect nanoparticle architecture to measurable outcomes such as tonsillar deposition, epithelial uptake, immune activation, and local tolerability. Full article