Search Results (918)

In this study, manganese ferrite was grown on the surface of a low-cost powder substrate of a guava leaf using the co-precipitation method. The resulting material was characterized using various spectroscopic and microscopic techniques. The composite was formed through the electrostatic and non-electrostatic interactions between the manganese ferrite nanoparticles, and the functional groups present on the guava leaf substrate; consequently, a high content of functional groups was observed in the synthesized composite through the Fourier transform infrared spectroscopy. The average size of the nanoparticles grown on the guava leaf substrate was determined to be between 3 and 5 nanometers. The synthesized composite material was utilized for adsorption applications, employing Methylene blue dye as a model adsorbate. Methylene blue was removed from the aqueous solutions under various conditions—including variations in the pH, contact time, temperature, and concentration. Under optimal conditions, it was observed that an adsorbent dosage of 2 g L⁻¹ was capable of removing approximately 99% of the dye from a 10 mg L⁻¹ dye solution at pH 7. The dye removal efficiency (%) decreased with the increasing temperature, indicating an exothermic process; this was further confirmed by the thermodynamic parameter analysis (specifically, the change in enthalpy, or ΔH), which yielded a negative value. Gibbs Free Energy (ΔG) also yielded a negative value, signifying the feasibility and spontaneity of the adsorption process. In this study, the adsorption process followed the Freundlich isotherm model, with the value of ‘n’ falling between 1 and 10, which is indicative of heterogeneous adsorption. The adsorption kinetics were determined to follow a pseudo-second-order model, and the overall rate-limiting step of the process was identified as intraparticle diffusion. To assess the sustainability and stability of the adsorbent, regeneration and reusability experiments were conducted. The results revealed that the modified guava leaf performed effectively for up to five cycles, achieving an adsorption efficiency of approximately 24% after the final cycle. Thus, the developed adsorbent proved to be an effective material for the removal of Methylene blue dye. Full article

The accelerating generation of waste streams is observed globally. Spanning lignocellulosic biomass, plastic waste, sewage sludge, and industrial residues, this review presents both an urgent management challenge and a compelling materials opportunity. Carbon materials derived from these waste streams offer a sustainable route to functional carbons applicable in electrochemical energy storage, adsorption, heterogeneous catalysis, and high-temperature applications. Yet their rational design remains constrained by incomplete understanding of the relationships between feedstock composition, processing pathway, structural characteristics, and functional performance. This review provides an integrated analysis of waste-derived carbon materials from processing pathways to structure–property–function relationships. The principal feedstock categories are examined for their compositional characteristics and implications for carbon yield and structure. Five primary processing routes are assessed. The five routes examined are pyrolysis, hydrothermal carbonisation, physical and chemical activation, and microwave-assisted processing. They are assessed comparatively with emphasis on structural outcomes and governing parameters. The resulting structural characteristics are discussed. These are morphology, hierarchical pore architecture, surface chemistry, heteroatom doping, and crystallinity. They are discussed alongside their characterisation methods and known limitations as performance predictors. Structure–property relationships are examined quantitatively. Heteroatom-doped hierarchical porous carbons achieve 612 F/g specific capacitance. Turbostratic hard carbons deliver 450 mAh/g sodium storage with over 90% retention. Hierarchical porous carbons demonstrate CO₂ uptake of 5.0 mmol/g and dye adsorption exceeding 9000 mg/g under optimised laboratory conditions; these values reflect individual studies and are not directly comparable across systems. Biomass-derived sulfonated carbon catalysts sustain biodiesel yields above 90% over multiple cycles. Challenges of feedstock variability, process scalability, environmental compliance, and economic feasibility are addressed, and machine learning-guided design, standardised characterisation methodology, and circular economy policy frameworks are identified as key enablers for translating laboratory performance into industrial reality. Full article

Zeolite-based composite nanomaterials represent a versatile and mechanistically rich platform for the removal of organic micropollutants (OMPs)—including pharmaceuticals, endocrine-disrupting compounds, pesticides, and per- and polyfluoroalkyl substances (PFAS)—from contaminated water systems. Although pristine zeolite frameworks provide well-defined microporous architectures, tunable Si/Al ratios, and ion-exchange capacity, their intrinsic hydrophilicity restricts interaction diversity and limits performance toward the structurally heterogeneous OMPs prevalent in real aquatic environments. Composite integration with carbonaceous nanophases, functional polymers and surfactants, and catalytically active metal oxide nanoparticles substantially extends this interaction repertoire, yielding multifunctional materials whose adsorption performance exceeds that of the individual components. Drawing on a systematic survey of peer-reviewed literature published between 2016 and 2026, this review develops a mechanism-oriented, structure–property–performance framework examining five dominant adsorption mechanisms—electrostatic attraction, π–π stacking, hydrogen bonding, hydrophobic partitioning, and micropore confinement—in relation to composite nanoarchitecture, surface chemistry, and structural parameters. The modulating influence of realistic water matrix conditions on adsorption efficiency is critically assessed, alongside challenges of regeneration, long-term stability, metal leaching, and the persistent gap between laboratory-scale synthesis and scalable deployment. Priority research directions are identified, including standardized performance evaluation under environmentally representative conditions and rational design of hierarchical multifunctional nanocomposites from earth-abundant and waste-derived precursors. Full article

This study investigates the agglomeration of chromium-containing dust from ferroalloy production using rigid vacuum extrusion. Direct utilization of fine technogenic materials in submerged arc furnaces is limited due to poor gas permeability, increased dust generation, and unstable smelting conditions. The aim of this work was to compare bentonite and polymer binders in brex production and evaluate their metallurgical applicability. Chromium-containing dust from the gas-cleaning system of the Aktobe Ferroalloy Plant (TNC Kazchrome JSC, ERG) was characterized using chemical analysis and SEM/EDS methods. The material exhibited a heterogeneous structure composed mainly of chromium-containing spinel, silicate, and oxide phases. Pilot-industrial extrusion tests were performed using J.C. Steele & Sons equipment with bentonite (10 wt.%) and polymer binder TD 021.005.BS (2.5 wt.%). The polymer binder provided improved brex geometry and significantly higher mechanical strength, achieving impact strength values up to 89.5% after curing. SEM/EDS analysis of the obtained brexes confirmed the formation of a dense agglomerated structure with uniform distribution of chromium-containing phases. Thermodynamic modeling using FactSage 8.4 showed that brex addition does not significantly affect slag composition, phase equilibria, or metal quality during high-carbon ferrochrome smelting. The results demonstrate the feasibility of polymer binders for efficient recycling of chromium-containing technogenic wastes by rigid vacuum extrusion. Full article

Barely Visible Impact Damage (BVID) in heterogeneous polymer-matrix composites remains difficult to detect because subtle damage signatures are often masked by complex architectures, hybrid textures, and overlapping failure morphologies. This study therefore presents an experimentally grounded, physics-aware, and statistically validated vision-based inspection framework rather than a purely detector-centered benchmarking exercise. Real post-impact images were obtained from controlled low-velocity impact experiments on 20 composite architectures and 60 physical specimens, yielding approximately 2000 images across laminated, hybrid, textile-reinforced, and sandwich structures. The dataset was organized using a specimen-disjoint splitting protocol to prevent leakage across training, validation, and test subsets. To improve robustness while preserving physical realism, a physically grounded Albumentations strategy was developed using only physically admissible transformations and explicit exclusion of non-physical operations that could distort damage morphology or surface continuity. Model development was further complemented by a hybrid hardware workflow in which cloud-based GPU training was combined with deployment-oriented inference profiling on resource-constrained edge-like hardware, thereby linking detection accuracy to practical industrial feasibility. In addition, model performance was evaluated under a standardized training budget and validated through repeated runs, Friedman significance testing, and Holm-corrected Wilcoxon signed-rank pairwise comparisons to ensure error-controlled interpretation of inter-model differences. Across the evaluated compact YOLO families, YOLO26s delivered the strongest overall performance, reaching 0.841 mAP@0.5, 0.586 ± 0.004 mAP@0.5:0.95, and an F1-score of 0.809, while YOLO11s achieved the highest precision and YOLO26n remained competitive in recall with nano-level compactness. Overall, the results show that experimentally generated heterogeneous composite data, morphology-preserving augmentation strategy development, leakage-aware dataset design, deployment-oriented computational profiling, and statistically grounded validation together provide a more robust and application-relevant basis for automated BVID detection in polymer-matrix composite structures. Full article

The design of sustainable composite materials requires approaches that integrate performance, durability, and circularity. In this study, jackfruit seed residue (JSR), a starch-rich agro-industrial by-product, is explored as a multifunctional biopolymeric component in cement-based rendering composites within a Safe and Sustainable by Design (SSbD) framework. Despite conventional strategies based on purified polymers or synthetic admixtures, JSR is incorporated in its unprocessed form, preserving its intrinsic chemical and structural heterogeneity and enabling complex physicochemical interactions within the composite matrix. Mortar formulations containing 0%, 3%, 5%, and 7% JSR (by binder mass) were evaluated through fresh-state, mechanical, and durability tests, combined with multiscale characterization (X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, and X-ray fluorescence). The incorporation of JSR enhanced workability and significantly reduced capillary water absorption (up to 25.83%), while maintaining mechanical performance within the typical range for rendering applications, with strength gains observed at 28 days. The observed behavior is attributed to synergistic mechanisms, including water retention, internal curing, and microfiller effects, as well as ionic contributions from the mineral fraction of the residue. Further, microstructural analysis revealed refinement of the interfacial transition zone and modification of the pore network, indicating reduced transport connectivity rather than a simple decrease in total porosity. These results demonstrate that unprocessed bio-residues can act as effective multifunctional components in cementitious composites, enabling the tuning of structure–property relationships and offering a scalable pathway toward low-impact composite materials aligned with circular economy principles. Full article

Analytical studies of archeological materials often face challenges, such as the merging of heterogeneous, multidimensional datasets from complementary analytical techniques, and incorporating site- and user-defined parameters. In this study, a data fusion methodology is applied that combines micro-X-ray fluorescence (micro-XRF) spectrometry and handheld Raman spectroscopy to investigate degradation layers and identify pollution sources on two monuments in an urban background: the Temple of Hephaestus and the Byzantine Church of Ag. Theodoroi, in Athens, Greece. A total of 12 samples were collected for laboratory measurements and 32 in situ measurements were conducted. Statistical and unsupervised machine learning tools, namely correlation analysis, Principal Component Analysis and k-means clustering, were applied to the merged datasets. Additionally, selected elements’ ratios were calculated to infer their sources. The black crusts were identified as heterogeneous mixtures of calcium sulfate dihydrate, calcite, and particulate pollutants, with their composition reflecting their preservation state. Vehicular emission indicators were dominant in both sites, while secondary domestic heating pollutant indicators were more prevalent at Ag. Theodoroi. Orientation had a minor role compared to pollutant sources in differentiating degradation patterns. The integrated comparison of the different outputs highlighted the interpretive potential of the approach, particularly in improving the readability of the multivariate structure and supporting the development of targeted conservation strategies for monuments in polluted urban contexts. Full article

The pharmaceutical development of cannabis-based medicinal products is challenged by significant variability in the quality, composition, and standardization of plant-derived active pharmaceutical ingredients (APIs). In Ukraine, despite recent legislative liberalization, a substantial shortage of standardized raw materials continues to limit the development of innovative dosage forms. This study analyses international practices among API manufacturers to identify technological parameters necessary to overcome domestic market barriers and support the implementation of advanced drug delivery systems. Content analysis was conducted on regulatory documentation, professional literature, and manufacturers’ technical specifications. Candidate evaluation followed predefined inclusion and exclusion criteria. The study assessed compliance with Good Manufacturing Practice (GMP) requirements, extraction and purification technologies, the extent of analytical characterization, and batch-to-batch reproducibility. Purposive sampling enabled a comparative analysis of various technological approaches. Marked heterogeneity was observed in API standardization and analytical control indicators among manufacturers. Possession of a GMP certificate was found necessary but may be insufficient to ensure the pharmaceutical equivalence of materials. Differences in extraction methods and purification levels may affect stability profiles, pharmaceutical development strategies, and risk management related to final product quality. The findings demonstrate that manufacturer selection is a critical decision point in pharmaceutical development, with substantiated supplier choice directly influencing dosage form development and regulatory compliance. Full article

The functional performance and structural integrity of natural rock materials under fluctuating environmental stressors are pivotal for their advanced applications. As a non-ionizing and radiation-free technology, terahertz (THz) spectroscopy offers a safe and promising alternative for non-destructive testing (NDT), uniquely capable of being deployed in open and unshielded environments. However, limited penetration depth, exacerbated by both the dense geological matrix and the extreme sensitivity of THz waves to moisture states, has long hindered its widespread application in rock characterization. This study establishes a quantitative Terahertz Time-Domain Spectroscopy (THz-TDS) framework to characterize four lithologies under drying–wetting cycles. Exponential signal attenuation across thicknesses was quantified based on the Beer–Lambert law, with attenuation coefficients ranging from 0.15 to 0.74 per millimeter. Planar transmission imaging successfully visualizes lithologic and moisture-dependent heterogeneity: limestone exhibits a dense, homogeneous structure with stable amplitude distribution; sandstone and purple sandstone show parallel statistical trends, reflecting uniform pore networks; and granite demonstrates the most pronounced imaging contrast under varying moisture states, driven by complex grain-boundary scattering. The findings reveal that THz transmission is dictated by the synergistic effects of mineral compositions and pore structures: scattering at grain boundaries and fractures leads to significant energy dissipation, whereas clay-rich lithologies exhibit the highest sensitivity to moisture variations due to water adsorption and interfacial polarization effects. As an exploration of THz technology in the non-destructive evaluation of rock materials, these findings establish an analytical framework for the quantitative assessment of microstructure evolution. Full article

Large language models (LLMs) are increasingly used in professional examinations, but their relative performance on dental board-style questions remains unclear. This study compared two reasoning-optimized models, GPT-o3 and GPT-5T, with a general-purpose multimodal model, GPT-4o, using 399 Japanese dental board-style multiple-choice questions from 2018 to 2022. All questions were presented in Japanese, and items originally accompanied by charts, photographs, or other figures were analyzed separately from items without visual materials. Accuracy and item-level agreement were assessed using pairwise McNemar tests, stratified analyses according to the original presence of visual materials, the Breslow–Day test for homogeneity of odds ratios, and two-proportion z-tests. GPT-5T achieved the highest overall accuracy (294/399, 73.7%), followed by GPT-o3 (257/399, 64.4%) and GPT-4o (255/399, 63.9%). Pairwise McNemar tests showed that GPT-5T outperformed both GPT-4o (Holm-adjusted p = 0.00098) and GPT-o3 (Holm-adjusted p = 0.00072), whereas GPT-o3 and GPT-4o did not differ significantly (Holm-adjusted p = 0.920). Accuracy was lower for questions originally containing visual materials than for questions without such materials across all three models (GPT-4o: 49.7% vs. 72.2%; GPT-o3: 55.1% vs. 69.8%; GPT-5T: 59.9% vs. 81.8%). The advantage of GPT-5T was more evident in questions without visual materials, and heterogeneity across question formats was observed for GPT-5T versus GPT-o3. GPT-5T showed the strongest performance in this dataset. Questions originally containing visual materials were associated with lower accuracy across all models. Because the comparison was based on distinct item groups rather than experimentally manipulated visual conditions, this result should be interpreted as a difference across question formats and may also reflect differences in item composition and difficulty between the two groups. Full article

With the rapid expansion of wind energy infrastructure, there is an increasing accumulation of wind turbine blade waste (WTBW), which is mainly composed of glass fiber-reinforced thermosetting composites. Due to the irreversible nature of polymer crosslinking, conventional recycling methods remain limited. In this study, plasma vitrification was employed to convert WTBW into a reactive calcium-aluminum-silicate slag suitable for use in geopolymer materials. Plasma treatment at a temperature of approximately 2750 K resulted in the formation of predominantly amorphous vitrified slag (VS). Structural characterization using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS) revealed the spatial heterogeneity of the VS. This heterogeneity was influenced by thermal gradients and varied between samples collected from different slag discharge zones, both vertically and horizontally from the reactor. All VS samples contained between 30 and 89% amorphous phase and 10–55% anorthite, with the proportions varying by sampling location. Chemical stability tests showed the dissolution of calcium and aluminum in acidic media, resulting in a silica-enriched residual structure in which the Ca and Al content decreased to less than 0.5 at.% after 100 days. In contrast, exposure to alkaline media caused only minimal surface reorganization—the addition of 5 wt.% VS to acid-based geopolymers made with two metakaolin precursors resulted in a 35% decrease in the mechanical strength of pure metakaolin-based systems. In contrast, when metakaolin containing illite impurities was used, strength values were similar to those of the reference geopolymer. The results quantitatively demonstrate that plasma-derived slag exhibits composition-dependent reactivity, directly linked to its amorphous content and dissolution behavior. Full article

(1) The growing interest in the use of natural and sustainable ingredients highlights the investigation of vegetable oils in dermato-cosmetic applications. In this context, the vegetable oil obtained from walnut (Juglans regia L.) is of actual interest due to its composition rich in unsaturated fatty acids. The aim of the present study was to investigate and characterize walnut oil from a physicochemical, structural, and rheological point of view. (2) The oil was obtained by a cold pressing process from walnut seeds, with a yield of about 51.03 ± 1.41%, and subsequently analyzed by complementary methods. (3) The results show an acceptable physicochemical profile, characterized by appropriate values of density, pH, and spreadability. The oxidative stability indicated a moderate resistance to degradation, specific to oils rich in polyunsaturated fatty acids. Fourier infrared transform spectrometry (FTIR) analysis confirmed the presence of functional groups characteristic of triglycerides, without indications of advanced oxidation, and atomic force microscopy (AFM) investigations revealed a heterogeneous morphology. The rheological properties indicated a pseudoplastic behavior, favorable for topical application. The determination of heavy metals confirmed the safety of the raw material for the intended dermato-cosmetic use. While arsenic levels were slightly above the strict Codex Alimentarius limits for foodstuffs, all values remained within the safety ranges established for cosmetic ingredients. A total of six fatty acids were found in cold-pressed walnut oil, determined using GC-MS methods. The number of compounds identified in the silylated sample was found to be 17. The antioxidant activity determined using DPPH and ABTS methods was generally considered good and relatively stable over time. The measured sun protection value (SPF) demonstrates a favorable capacity to act as a photoprotective ingredient against ultraviolet (UV) radiation. (4) Overall, the results demonstrate that walnut oil presents adequate physicochemical and structural properties, supporting its further use as a potential cosmetic raw material. Full article

This article presents preliminary research on the development of a cast iron–ceramic composite for modern braking systems, such as brake discs. The composite matrix is gray cast iron with flake graphite (EN-GJL-150). The reinforcing phase is a porous ceramic composed of SiC and Al₂O₃ particles introduced separately (10% each) and together (70% SiC + 30% Al₂O₃). These particles were applied as a suspension onto polyurethane foam, yielding a ceramic structure with a pore density of up to 10 ppi. The resulting insert was placed in a mold cavity, and cast iron was poured into it. The resulting samples were treated as brake disc material, with a pad made of the commercial friction material P50094 serving as the countersample. Tribological tests showed that the lowest sample wear (average 2.23 mg/5000 m) was achieved for the composite reinforced with SiC + Al₂O₃ particles. This is probably due to the synergy between the antifriction properties of these particles and the lower friction coefficient (µ = 0.180–0.22). Similar mass loss values and the smallest difference between the tested samples were observed for composites with SiC particles (3.01 mg/5000 m) and Al₂O₃ (3.30 mg/5000 m). The second part consisted of microstructural studies. Microstructural analysis of the EN-GJL-150 + SiC + Al₂O₃ composite revealed a previously unobserved nucleation phenomenon at the cast iron–ceramic interface. This confirmed the general assumptions of Riposan’s theory regarding the involvement of oxide microinclusions and complex manganese sulfides of the (Mn, X)S type in the nucleation and crystallization of graphite precipitates. It was also found that, in the case of “in situ” GJL-150 + SiC + Al₂O₃ composites, this theory should account for the beneficial role of ceramic particles in promoting the uniform distribution of type A graphite flakes, which nucleate on their surfaces in the transition zone. Thus, the nucleating role of oxide microinclusions (the first stage of Riposan’s theory) could be taken over by SiC and Al₂O₃ particles, constituting a substrate for the heterogeneous nucleation of (Mn, X)S sulfides. Full article

Background: Biodentine is widely used in vital pulp therapy due to its bioactivity and biocompatibility. However, treatment success depends not only on the material but also on the restorative approach. Clinically, Biodentine may be used as a temporary bulk restoration before delayed placement of a composite or immediately covered with a definitive composite. Aim: To evaluate clinical outcomes reported for delayed composite placement after temporary Biodentine restoration and immediate composite restoration following Biodentine pulp capping in permanent teeth. Methods: A systematic review was conducted in accordance with PRISMA guidelines and registered with PROSPERO (CRD420261325248). Searches were performed in multiple databases. Clinical studies on Biodentine pulp capping reporting outcomes for either delayed or immediate composite restoration were included. Study selection, data extraction, and quality assessment were performed by two reviewers using Joanna Briggs Institute tools. Fourteen studies (8 randomized controlled trials and 6 cohort studies) were included. Results: Considerable heterogeneity was observed in study design and clinical protocols. Most included studies evaluated one of the two strategies separately, so the review results could not be interpreted as a direct comparison. In direct pulp capping, success rates ranged from 74–100% (delayed) and 79–100% (immediate). In indirect pulp capping, success rates ranged from 77.8–88% (delayed) and 80–95.2% (immediate). Meta-analysis was not feasible. Conclusion: Based on low certainty of evidence, both strategies show favorable outcomes, but current evidence does not support the superiority of either approach. Further well-designed comparative studies are needed. Full article

Background/Objectives: Root perforation treatment is essential for restoring the tightness of the root system, preventing periradicular inflammation and tooth loss. The present study aimed to evaluate the biocompatibility of Ketac™ Molar EasyMix as well as conduct a thorough morphological and structural characterization of the material, considering its potential use in managing root perforations. Methods: Morpho-structural characterization was performed by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), Fourier-transform infrared spectroscopy (FT–IR), and X-ray diffraction (XRD). Biocompatibility tests were performed on osteosarcoma cell line (ATCC—G 292 CRL-1423), monitoring metabolic activity and cell viability (MTT, n = 3), as well as the inflammatory response (nitric oxide—NO, n = 6), after 24 and 48 h of incubation. The control group consisted of cells unexposed to the material. Results: Microstructurally, the material exhibits a heterogeneous structure, along with pores and cracks. The specific bonds of the material, including both organic acid (COO⁻, O-H) and the glass components (Si-O-Al, Ca-O, C-F), were identified by FT-IR, while the crystalline phase composed of calcium fluorolanthanate was determined by XRD. Moreover, in vitro metabolic activity and viability test (MTT) showed a decrease of ~28% (p = 0.029) and ~30% (p = 0.150) after 24 and 48 h for samples incubated with Ketac™ Molar EasyMix. The statistically significantly increased levels of NO (p = 0.002, p = 0.004) suggest that the cells are trying to adapt to the environment that they have been exposed to. Conclusions: Within the limitations of the present study, under the tested conditions, our results suggest that Ketac™ Molar EasyMix maintained cell viability close to the 70% threshold defined by ISO 10993-5:2009, indicating a borderline biological response, a feature that may be influenced by the composition and behavior of the material. Full article