Search Results (3,563)

A coherent standardization framework is essential for the industrial deployment of cellulose nanomaterials (CNMs). Although CNMs offer attractive properties for diverse industrial applications, their distinct morphological types—cellulose nanocrystals (CNCs), individualized cellulose nanofibrils (iCNFs), and entangled cellulose nanofibrils (eCNFs)—introduce morphological complexity that hinders reproducible quality evaluation. ISO has established terminology and several test method standards; however, testing standards remain limited for CNCs and iCNFs, and are still lacking for eCNFs, leaving a significant gap between material characterization and industrial use. This study proposes a structured framework that aligns terminology, test method, testing, and specification standards along the CNM industrialization pathway. The framework highlights the essential role of testing standards as the appropriate evaluation basis for CNMs at their present developmental stage, in contrast to specification standards suited to mature materials with clearly defined applications. A complementary scenario-based methodology is also introduced to support coherent and reproducible development of individual testing standards. By positioning existing ISO CNM standards within this pathway and clarifying the evaluative and bridging functions of testing standards, this study provides an industry-oriented foundation for reliable CNM quality assessment. The conceptual approach may also support standardization strategies for other bio-based materials in similarly early stages of industrialization. Full article

This study investigates a metakaolin-based geopolymer matrix in which two types of non-recyclable mirror glass waste (MGW) were used as alternative aggregates. The composition, properties and contents of MGW materials as well as their impact on the structure and performance of the geopolymer composites (MGW-Gs) have been characterized using X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TG), and Fourier transform infrared spectroscopy (FTIR). Mechanical properties, porosity and thermal conductivity have been evaluated, and compared with silica sand reference composites. The results show that MGW-based composites achieved flexural strengths of 3.9–5.7 MPa and compressive strengths of 60–70 MPa, which are lower than those of sand-based materials (8–11 MPa and up to 93.5 MPa, respectively) but remain adequate performance for applications with moderate load. FTIR analysis has indicated that the incorporation of MGW does not adversely affect the geopolymer network. All composites display similar porosity (approximately 18–22%) and water absorption (12–14%), while MGW incorporation has improved their thermal stability and significantly reduced their thermal conductivity to values below 0.53 W·m⁻¹·K⁻¹, compared with up to 1.09 W·m⁻¹·K⁻¹ for sand-based composites, emphasizing their insulation potential and sustainability benefits. The findings indicate that MGW aggregates can influence the microstructure, mechanical performance, and thermal properties of geopolymer composites, suggesting their potential use in specific construction applications. Full article

One of the major issues in the energy intensive industries (EIIs) operation is corrosion control. Particularly, in refineries, corrosion causes 33% of malfunctions, especially due to the deterioration of the metallic materials and, therefore, the shortening of the useful life of equipment and installations. To face this problem, novel polymer-derived ceramic (PDC) coatings have been formulated, developed and characterized by physical and chemical tests. Different formulations were analyzed on a lab-scale through accelerated corrosion tests under acidic environments using electrochemical impedance spectroscopy (EIS) to evaluate their corrosion performance when exposed to near-real operating conditions. The optimized formulation will be used as a barrier in stainless-steel pipelines to improve the energy performance of EIIs by reducing energy losses due to excess cooling of components, maximizing the thermal efficiency of equipment, increasing the service life of equipment and reducing operation and maintenance (O&M) costs and downtime. Full article

Chronic and complex wounds, including diabetic foot ulcers, venous leg ulcers, burns and post-surgical defects, remain difficult to manage due to persistent inflammation, impaired angiogenesis, microbial colonization and insufficient extracellular matrix (ECM) remodeling. Conventional dressings provide protection, but they do not supply the necessary biochemical and structural signals for effective tissue repair. This review examines recent advances in hydroxyapatite–collagen (HAp–Col) composite dressings, which combine the architecture of collagen with the mechanical reinforcement and ionic bioactivity of hydroxyapatite. Analysis of the literature indicates that in situ and biomimetic mineralization, freeze-drying, electrospinning, hydrogel and film processing, and emerging 3D printing approaches enable precise control of pore structure, mineral dispersion, and degradation behavior. Antimicrobial functionalization remains critical: metallic ions and locally delivered antibiotics offer robust early antibacterial activity, while plant-derived essential oils (EOs) provide broad-spectrum antimicrobial, antioxidant and anti-inflammatory effects with reduced risk of resistance. Preclinical studies consistently report enhanced epithelialization, improved collagen deposition and reduced bacterial burden in HAp–Col systems; however, translation is limited by formulation variability, sterilization sensitivity and the lack of standardized clinical trials. Overall, HAp–Col composites represent a versatile framework for next-generation wound dressings that can address both regenerative and antimicrobial requirements. Full article

Controlled-release systems must translate material design choices into predictable pharmacokinetic (PK) profiles, yet purely mechanistic or purely data-driven models often underperform when tuning complex polymer networks. Here, we develop tunable poly(vinyl formal) membranes (PVFMs) for diclofenac delivery and integrate classical kinetic analysis with a Generalized Regression Neural Network (GRNN) to connect formulation variables to release behavior and PK-relevant targets. PVFMs were synthesized across a gradient of crosslink densities by varying HCl content; diclofenac release was quantified under standardized conditions with geometry and dosing rigorously controlled (thickness, effective area, surface-area-to-volume ratio, and areal drug loading are reported to ensure reproducibility). Release profiles were fitted to Korsmeyer–Peppas, zero-order, first-order, Higuchi, and hyperbolic tangent models, while a GRNN was trained on material descriptors and time to predict cumulative release and flux, including out-of-sample conditions. Increasing crosslink density monotonically reduced swelling, areal release rate, and overall release efficiency (strong linear trends; r ≈ 0.99) and shifted transport from anomalous to Super Case II at the highest crosslinking. Classical models captured regime transitions but did not sustain high accuracy across the full design space; in contrast, the GRNN delivered superior predictive performance and generalized to conditions absent from training, enabling accurate interpolation/extrapolation of release trajectories. Beyond prior work, we provide a material-to-PK design map in which crosslinking, porosity/tortuosity, and hydrophobicity act as explicit “knobs” to shape burst, flux, and near-zero-order behavior, and we introduce a hybrid framework where mechanistic models guide interpretation while GRNN supplies robust, data-driven prediction for formulation selection. This integrated PVFM–GRNN approach supports rational design and quality control of controlled-release devices for diclofenac and is extendable to other therapeutics given appropriate descriptors and training data. Full article

Introduction: Incomplete polymerization of in vivo composite resins (CR) poses a significant problem, with monomer-to-polymer conversion rates ranging from around 60 to 75%. Furthermore, oxygen exposure hampers polymerization in the surface layers. This research aims to evaluate the autophagy-inducing potential of three types of CRS and to explore the role of the Akt/mTOR–autophagy–apoptosis crosstalk in composite resin-induced autophagy. The study uses human gingival fibroblasts and three composite materials (M1 and M2, which are 3D printed, and M3, which is milled). Materials and Methods: SEM analysis was performed on the dental materials, and cells kept in contact for 24 h were subjected to tests including the following: MTT, LDH, NO, immunological detection of proteins involved in autophagy and apoptosis, as well as immunofluorescence tests (Annexin V and nucleus; mitochondria and caspase 3/7; detection of autophagosomes). Results: The results showed statistically significant decreases in cell viability with M1 and M2, linked to increases in cytotoxicity and oxidative stress (LDH and NO). Using multiplex techniques, significant increases in glycogen synthase kinase 3 beta (GSK3b) protein were observed in both M1 and M2; a decrease in mTOR (mechanistic target of rapamycin) expression was noted in M1 and M3. Immunofluorescence tests revealed an increase in Annexin V across all materials studied, and an increase in autophagosomes in M1 and M2, whereas a decrease was observed in M3. Conclusions: The relationship between apoptosis and autophagy is highly complex, indicating they may occur sequentially, coexist, or be mutually exclusive. Understanding this complex interplay can help in designing new 3D-printing protocols and monomer compositions to prevent autophagy imbalance. Full article

The rapid commercialization of next-generation photovoltaic (PV) technologies, particularly perovskite, thin-film roll-to-roll (R2R) architectures, and tandem devices, requires robust assessment of environmental performance at the level of industrial manufacturing processes. Environmental impacts can no longer be evaluated solely at the device or module level. Although many life-cycle assessment (LCA) studies compare silicon, cadmium telluride (CdTe), copper indium gallium selenide (CIGS), and perovskite technologies, most rely on aggregated indicators and database-level inventories. Few studies systematically compile and harmonize process-level life-cycle inventories (LCIs) for the manufacturing steps that differentiate emerging industrial routes, such as solution coating, R2R processing, atomic layer deposition, low-temperature annealing, and advanced encapsulation–metallization strategies. In addition, inconsistencies in functional units, system boundaries, electricity-mix assumptions, and scale-up modeling continue to limit meaningful cross-study comparison. To address these gaps, this review (i) compiles and critically analyzes process-resolved LCIs for innovative PV manufacturing routes across laboratory, pilot, and industrial scales; (ii) quantifies sensitivity to scale-up, yield, throughput, and electricity carbon intensity; and (iii) proposes standardized methodological rules and open-access LCI templates to improve reproducibility, comparability, and integration with techno-economic and prospective LCA models. The review also synthesizes current evidence on recycling, circularity, and critical-material management. It highlights that end-of-life (EoL) benefits for emerging PV technologies are highly conditional and remain less mature than for crystalline-silicon systems. By shifting the analytical focus from technology class to manufacturing process and life-cycle configuration, this work provides a harmonized evidence base to support scalable, circular, and low-carbon industrial pathways for next-generation PV technologies. Full article

The textile sector provides essential goods, yet it remains environmentally and socially intensive, driven by high water use, pesticide dependent monocropping, chemical pollution during processing, and growing waste streams. This review examines credible pathways to sustainability by integrating emerging plant-based fibres from hemp, abaca, stinging nettle, and pineapple leaf fibre. These underutilised crops combine favourable agronomic profiles with competitive mechanical performance and are gaining momentum as the demand for demonstrably sustainable textiles increases. However, conventional fibre identification methods, including microscopy and spectroscopy, often lose reliability after wet processing and in blended fabrics, creating opportunities for mislabelling, greenwashing, and weak certification. We synthesise how advanced molecular approaches, including DNA fingerprinting, species-specific assays, and metagenomic tools, can support the authentication of fibre identity and provenance and enable linkage to Digital Product Passports. We also critically assess environmental Life Cycle Assessment (LCA) and social assessment frameworks, including S-LCA and SO-LCA, as complementary methodologies to quantify climate burden, water use, labour conditions, and supply chain risks. We argue that aligning fibre innovation with molecular traceability and harmonised life cycle evidence is essential to replace generic sustainability claims with verifiable metrics, strengthen policy and certification, and accelerate transparent, circular, and socially responsible textile value chains. Key research priorities include validated marker panels and reference libraries for non-cotton fibres, expanded region-specific LCA inventories and end-of-life scenarios, scalable fibre-to-fibre recycling routes, and practical operationalisation of SO-LCA across diverse enterprises. Full article

This article presents an in-depth analysis of the application of thermal deposition techniques, in particular thermal spraying, to improve the properties of materials used in agricultural components that work the soil, such as agricultural plows (mainshare and foreshare). Due to the difficult operating conditions, characterized by abrasive wear, mechanical shocks, and chemical exposure from various soils, these surface coatings aim to increase the durability and corrosion resistance of the materials of components intended for working with the soil. The study investigates thermal deposition methods and their effects on the microstructure, hardness, and friction resistance of the obtained layers. The study highlights experiments that reveal significant improvements in mechanical properties, highlighting superior behavior in real conditions of agricultural use. Nevertheless, soil types significantly influence the abrasive wear rate of the components and also their corrosion, which depends on the soil pH. The results confirm that the use of thermal deposition represents a sustainable and effective solution for extending the life of plows, thus reducing maintenance costs and increasing the efficiency of agricultural processes. This research contributes to the optimization of agricultural equipment, providing an innovative approach for adapting plows to the increasing demands of agricultural exploitation. Full article

This study investigates the influence of manufacturing technology on the structural, mechanical, and antifriction properties of a new self-lubricating composite based on ShKh15 bearing-steel grinding waste to which a CaF₂ solid lubricant was added. The developed process involves regenerating grinding waste, mixing with CaF₂ powder, pressing, and sintering. This process ensures the formation of a micro-heterogeneous structure consisting of a metallic matrix with uniformly distributed CaF₂ particles. The strengthening phases and their distribution determine the composite’s tribological behavior under operating conditions of 100–200 rpm and 1.0 MPa in air. Compared to conventional cast bronze, the material exhibits superior wear resistance and a lower friction coefficient. During friction, self-renewing antifriction films form on the contact surfaces due to chemical interactions between metallic elements, oxygen, and the solid lubricant, providing a continuous self-lubricating effect. The results demonstrate that adjusting the initial alloyed waste powders and the CaF₂ content makes it possible to control the structure and performance of the composite. This research highlights the potential of using industrial grinding waste to produce efficient antifriction materials while reducing environmental impact. Full article

To mitigate the impact of the conductor’s inherent tension–torsion coupling effect on conductor quality during tension stringing, a method for tension–torsion analysis and structural parameter optimization of conductors is proposed based on the radial basis function neural network (RBFNN) surrogate model. The layer-wise lay ratios of conductors are selected as the structural parameters. Using the tension–torsion coupling computational method for conductors, the layer-wise lay ratios are sampled by Latin hypercube sampling (LHS) to construct the sample data by computing conductor torque under different combinations. The RBFNN surrogate model is trained with the data, and its shape parameter is optimized through Leave-One-Out Cross-Validation (LOOCV), achieving a coefficient of determination R² close to 1 with minimal errors. Targeting torque minimization, the Non-Dominated Sorting Genetic Algorithm II (NSGA-II) is employed to identify the optimal combination of conductor lay ratio parameters, reducing conductor torque by approximately 18% under the same axial tension. For practical applications, prioritize the optimal combination for JL/G1A-630/45-45/7 and analogous conductors, and adopt the RBFNN model for rapid torque prediction. The proposed method also serves as a reference for design optimization of conductor structural parameters. Full article

Several studies have attempted to define the performance of most commercially available shade guides. The purpose of the present study was to compare the coverage errors of three commercial shade guides for a selected Greek population and to investigate whether there is a difference between the coverage errors of the three shade guides for different types of anterior teeth of the selected population. Adult participants with healthy maxillary anterior teeth were recruited for color assessment. Color coordinates were measured for central incisors, lateral incisors, and canines of 212 individuals. Tooth shades were measured at the middle third using the Spectroshade Micro spectrophotometer, and three shade guide systems (Ivoclar, Vitapan Classical, and 3D Master) were evaluated under standardized conditions for comparison. The coverage errors of Ivoclar and Vitapan classical shade guides were not significantly different from each other for all teeth and for the three tooth types separately. However, 3D Master shade guide exhibited significantly lower coverage errors for all teeth and for the three tooth types separately (p < 0.001). 3D Master performed better than the other two shade guides for shade matching with natural dentition in the selected population. Full article

Children’s skin is highly sensitive and prone to irritation, allergies, and infections, requiring special consideration in textile selection. Although clothing serves as a protective barrier, it can also pose a risk when dyed with toxic chemical colourants. This study explores the potential of multifunctional natural dyes as safer alternatives for children’s clothing, particularly for those with dermatological conditions. Cotton knitted fabrics were dyed through exhaustion with extracts of madder root (Rubia tinctorum L.), pomegranate peel (Ppe, Punica granatum L.), oxidised logwood (Logox, Haematoxylum campechianum L.), and tannin from quebracho (Schinopsis lorentzii Griseb.), both individually and in various combinations with or without potassium aluminium sulphate dodecahydrate (alum). The combination of madder and Ppe demonstrated the most promising multifunctional performance, being classified as a weak disinfectant against S. aureus (3.7 log reduction) and showing the highest antioxidant activity (92.6 ± 2.56% 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical reduction), while maintaining excellent results after washing. Moreover, these natural formulations expanded the achievable colour palette from each dye while maintaining moderate wash fastness. The results highlight the relevance of these findings to textile and fashion designers, offering sustainable tools for creating health-conscious, visually appealing garments. This research reinforces the potential of natural dyes and biomordants in developing functional textiles that support children’s wellbeing and environmental responsibility. Full article

This study focused on the development of a new concept for ablative thermal protection material, using a relatively new polymer matrix based on polysiloxane resin, which exhibits high-performance thermal properties. As a reinforcing element, graphite felt (GF/UHT) was selected. These new ablative materials were tested and characterized to evaluate their thermal properties through comparison with established/standard ablative materials based on phenolic resin and graphite felt (GF/Isophen). To evaluate them, two distinct types of thermal tests were performed. The first consisted of subjecting the ablative materials to a temperature of 1100 °C for a total duration of 10 min (with three different dwell times: 30 s, 120 s, and 300 s). A mass loss of 31% was recorded for the GF/UHT ablative material samples compared to the GF/Isophen material, where the mass loss reached approximately 68%. The second test consisted of exposure to an oxyacetylene flame at a temperature of 1600 °C. The GF/UHT samples had an improved behavior compared to the GF/Isophen samples, the latter being completely penetrated at the end of the test. Additionally, differential scanning calorimetry (DSC) tests were performed and characterized by FTIR spectroscopy and scanning electron microscopy. Full article

The increased test frequency inherent in Ultrasonic Fatigue Testing (UFT) is commonly observed to result in an increased fatigue resistance for ferritic, low-carbon steels. In this investigation, the fatigue response of S275J2 ferritic structural steel is evaluated at both 20 kHz and 50 Hz. At the ultrasonic frequency, an increase in the fatigue limit of 136 MPa and an increase in the finite life region of 150 MPa was observed, alongside a reduction in the slope of the S-N curve. By combining the S275J2 results with additional data from the literature, generalised versions of previously proposed frequency sensitivity models are produced by evaluating the model coefficients as a function of different combinations of the material properties. Additionally, a new frequency sensitivity model was proposed by evaluating the empirical change in the S-N curve coefficients as a function of these material properties. For all of the models, it was found that the best correlation was against the ferrite content divided by the tensile strength. The generalised forms of these models were rearranged to produce correction factors, which allow the conventional frequency fatigue response to be estimated based on the UFT test. The most reliable correction method was found to be using the empirical change in the S-N curve exponent. Full article