Search Results (3,856)

Polylactic acid (PLA) is one of the most promising bio-based and biodegradable polymers, yet its inherent brittleness limits its application in flexible film products. This study compares three mixing strategies, applied as four sample series, to improve the mechanical performance of PLA-based binary blends: (1) single-pass melt blending with poly(butylene adipate-co-terephthalate) (PBAT) or poly(butylene succinate) (PBS) at 10, 20, and 30 wt%; (2) addition of poly(ethylene glycol) (PEG 4000 or PEG 20000) as a plasticizer/compatibilizer at 1, 3, and 5 wt%; (3) double melt processing of PLA/PBAT and PLA/PBS blends. Thin films were characterised by tensile testing, differential scanning calorimetry (DSC), FTIR, SEM and contact angle measurements. Double processing emerged as the most effective approach, yielding elongation at break values up to approximately 137% for 70PLA/30PBAT blends, compared to 16.9% for the equivalent single-processed samples. Relative to the single-processed controls, double processing raised elongation at break by approximately 712% for 70PLA/30PBAT and 1201% for 70PLA/30PBS, and by 98% (80PLA/20PBAT), 175% (80PLA/20PBS) and 278% (90PLA/10PBAT); the latter three increases were statistically significant (p < 0.05). By contrast, PEG addition changed maximum stress by at most about 18% and never raised elongation at maximum stress above 6%. Two-way ANOVA confirmed that blend ratio was a significant factor for maximum stress (p < 0.001) whereas PEG molecular weight was not (p > 0.10). PEG addition produced moderate improvements in tensile stress, but did not replicate the ductility enhancement observed after reprocessing. DSC data confirmed a decrease in the glass transition temperature (Tg) and altered crystallisation behaviour in double-processed samples, consistent with improved interfacial compatibility. Contact angle results showed broadly similar surface wettability across all series, pointing to processing history, rather than surface chemistry, as the key variable governing final mechanical behaviour in these blends. Full article

In a previous clinical trial, it was shown that a probiotic blend (Bifidobacterium longum CECT 7347 (Esflorin1™), Lacticaseibacillus rhamnosus CECT 8361 (BPL15) and Lacticaseibacillus casei CECT 9104 (BPL4)) reduced oxidative stress in males engaging in intense exercise. The present study evaluated whether the probiotic blend’s functional properties are preserved after heat treatment and investigated the underlying mechanism of action using preclinical models. The antioxidant, immunomodulatory and intestinal effects of the heat-treated and probiotic blends were assed using in vitro assays and Caenorhabditis elegans (C. elegans) models. The heat-treated blend preserved the antioxidant activity by scavenging free radicals, reducing intracellular reactive oxygen species and enhancing survival in C. elegans under oxidative stress, possibly via sod-3 upregulation in the CF1553 strain. It also enhanced mitochondrial biogenesis and ATP production in C2C12 via AMPK phosphorylation. Both versions attenuated a gut inflammatory response, improved intestinal barrier in Caco-2 cells and C. elegans and exhibited immunomodulatory activity in U937 macrophages at the tested concentrations. These findings support the heat-treated blend as a promising postbiotic supplement to manage oxidative stress and other physiological alterations associated with intense exercise. Full article

Insect protein farming offers sustainable advantages in land efficiency, emission reductions, and bioconversion, yet optimizing the nutrient composition remains a major challenge for cost-effective production. This study investigates the co-regulatory mechanism between alkali-soluble protein (SpA) and the gut microbiota in black soldier fly larvae (Hermetia illucens) and their effect on protein conversion efficiency. Feeding trials with varying alfalfa/SpA ratios identified a wheat middlings/alfalfa meal blend at a (5:0 ratio) as optimal for promoting larval protein accumulation. SDS-PAGE and 16S rRNA analyses revealed a strong positive correlation between SpA and larval crude protein (R² = 0.82). The network analysis and Pearson correlation heatmap further confirmed positive correlations among SpA, larval protein, Enterococcus, and Ignatzschineria (p < 0.05), suggesting that high SpA in the substrate was associated with the enrichment of these taxa, which synergistically enhanced proteolysis through alkaline protease secretion (R² = 0.85) and chitinase-mediated gut remodeling. Multi-linear regression modeling verified SpA as a superior predictor of the crude protein content compared with total nitrogen (TN), improving the model’s coefficient of determination (R²) from 0.40 to 0.82. These findings highlight SpA’s higher bioavailability and its direct role in metabolic utilization. By integrating the feed composition, microbiome function, and host metabolism, this study established a regulatory network driving larval protein biosynthesis. The targeted modulation of dietary SpA content may offer a promising approach to enhance beneficial microbial communities and improve protein conversion efficiency in BSFL-rearing systems. These findings provide a theoretical basis for optimizing feed formulations to support sustainable insect protein production from organic waste. Full article

Ultra-high molecular weight polyethylene (UHMWPE) is the preferred bearing material for total knee arthroplasty, yet its limited service life (15–20 years) remains a clinical challenge. This study investigates graphene oxide (GO) nanoplatelets as reinforcing fillers to enhance the mechanical and tribological performance of UHMWPE for longer-lasting implants. GO/UHMWPE composites with 0–1 wt% GO were fabricated via solution blending and hot compression molding. Direct SEM imaging combined with oxygen elemental mapping confirmed uniform GO dispersion up to 0.5 wt%, whereas higher loadings induced agglomeration. Dynamic mechanical analysis showed that the storage modulus at 37 °C increased with GO content, peaking at 0.5 wt% (improved by ~28% over neat UHMWPE), then decreased due to aggregation. Tribological tests under dry reciprocating sliding revealed that GO progressively reduced the wear rate (up to ~45% at 1.0 wt%), but also raised the steady-state friction coefficient from 0.13 to 0.19, attributed to molecular chain anchoring. The optimal balance of enhanced stiffness and wear resistance, with only a marginal friction increase, was achieved at 0.5 wt% GO. The reinforcement mechanism involves efficient stress transfer to rigid GO sheets and reduced surface peeling. This work provides a robust processing route and direct dispersion evidence, offering practical guidance for designing high-performance UHMWPE composites for orthopedic applications. Full article

To demonstrate the applicability of the “dynamic self-vulcanization of bifunctional monomers” strategy for toughening polylactic acid (PLA), hydroxylated oleic acid (HOA) was synthesized via UV-initiated thiol–ene click chemistry, using oleic acid as the starting material. In the presence of an excess molar quantity of hexamethylene diisocyanate (HDI), the dynamic self-vulcanization of bifunctional monomers was employed to design PLA blends featuring extraordinary impact toughness. During the one-pot melt compounding, in situ formation and self-crosslinking of flexible poly(urethane-co-amide) (HPUA) toughening phase, together with its reactive compatibilization with the PLA matrix, were simultaneously accomplished. The aggregation of the HPUA domains enabled the morphological transformation of the PLA blend from a sea-island structure to a partially or fully bi-continuous one. At HPUA contents of 20 wt% or higher, the blend exhibited a bi-continuous morphology with a crosslinked HPUA network, attaining a notched impact strength exceeding 110 kJ/m² and an elongation at break above 200%. In particular, when the HPUA content reached 20 wt%, the resulting PLA blend exhibited optimal impact toughness, with a notched IS of 132.1 kJ/m² (30.7 times that of neat PLA). The primary toughening mechanism was determined to be the internal cavitation of the HPUA domains, which subsequently initiates the yielding of the surrounding PLA matrix. This study proposes an applicable and facile method for fabricating polymer materials that possess excellent impact toughness. Full article

In the present work, polyvinylpyrrolidone (PVP) was selected as the primary raw material and fully dissolved in N,N-dimethylformamide (DMF) solvent. Hydroxymethyl cellulose (HMC), acrylic acid (AA) monomer with outstanding chelating performance, and UR were added in sequence. On this basis, composite nanofiber membrane substrates of PVP/AA/HMC/UR were fabricated by means of electrospinning. Afterwards, silane coupling agent KH-560 was blended with polylactic acid (PLA). A uniform PLA/KH-560 functional coating was covered on the surface of the as-prepared nanofiber membrane via microfluidic coating treatment, and the target composite nanofiber adsorbent was ultimately obtained. Relevant performance characterization results indicated that moderate addition of HMC could greatly optimize the tensile strength of the membrane material, whereas excessive HMC dosage would cause a deterioration in mechanical strength. Moreover, the breaking elongation presented a slight declining trend, and the integrated mechanical stability of the membrane could fully meet the service demands for cyclic reuse. As a functional monomer, acrylic acid effectively boosted the material’s adsorption performance toward typical heavy metal ions, including Zn²⁺, Cu²⁺ and Pb²⁺. In simulated acidic wastewater generated from rare earth mining and extraction (pH = 3 and pH = 6.5), the removal efficiency of the as-prepared material for the three heavy metal ions all exceeded 95%. Even after being soaked in strong acid solution at pH 2 for 8 h, its adsorption rate was still maintained at 88.5%. In the cyclic experiment, the adsorption efficiency stayed above 75% after two recycling runs, decreased to roughly 55% in the third cycle, and dropped below 30% at the fourth reuse stage. The introduction of UR imparted remarkable acid-resistant structural stability to the composite material. The membrane structure remained complete without damage after long-term immersion in a pH 2 strong acid environment, and high-efficiency heavy metal removal capability could be guaranteed when the solution pH was not lower than 3. Targeting the practical treatment dilemma of acidic heavy metal-containing wastewater from rare earth exploitation and extraction, this research successfully developed a novel eco-friendly adsorbent featuring superior acid resistance, high adsorption performance and certain recyclability. This newly designed material makes up for the deficiencies in traditional adsorbents represented by activated carbon, including poor heavy metal removal ability in acidic media and secondary pollution risks resulting from disposable use. The research findings can offer a novel technical reference and feasible approach for the purification of acidic rare earth wastewater in practical engineering applications. Full article

Poly(lactic acid) (PLA) is a renewable and biodegradable polymer that has attracted considerable attention for sustainable packaging applications. However, its inherent brittleness limits its use in flexible films. In this study, PLA/poly(vinyl alcohol) (PVA) blend films were prepared by a single-solvent-casting rout at PLA/PVA weight ratios of 80/20, 70/30, 60/40, and 50/50 to investigate the influence of composition on their thermal, chemical, morphological, mechanical, optical, and water vapor barrier properties. Increasing the PVA content progressively modified the molecular organization of the system, the crystallization ability of the PLA phase and promoting a more homogeneous phase distribution. These structural changes resulted in a transition from a brittle behavior to increasingly ductile films, with the PLA/PVA 50/50 composition exhibiting the most favorable combination of tensile toughness, transparency, and morphological homogeneity, reaching an elongation at break of approximately 60%. In contrast, the increase in the hydrophilic phase led to higher water vapor permeability, highlighting the trade-off between mechanical performance and moisture barrier properties. Overall, the results demonstrate that controlling the PLA/PVA ratio provides an effective strategy for tailoring the morphology and functional properties of solvent-cast PLA/PVA films, contributing to a better understanding of the composition–structure–property relationships in biopolymer blends. Full article

The textile and clothing value chain faces increasing pressure to improve reuse and recycling rates, particularly in post-consumer scenarios, where garments must be rapidly assessed, classified, and routed toward appropriate end-of-life pathways. Post-consumer garment sorting must preserve reusable items while directing non-reusable textiles toward appropriate recycling or inspection pathways. This article presents a two-stage image-only decision-support framework that combines YOLO-based image classification, a locally executed vision–language model (VLM), two ConvNeXt-Tiny textile classifiers, and deterministic routing rules. In Stage 1, YOLO classifiers estimate garment type and dominant color, while Qwen2.5-VL-3B-Instruct VLM assesses visible stains, holes, pilling or lint, tags, dirt or discoloration, intentional distressing, condition, and supporting evidence. The backend validates these outputs and applies explicit precedence and uncertainty rules to assign categories A (resale), B (donation/reuse), C (recycling-oriented pre-sorting), or D (critical review). Stage 2 is triggered only for C/D garments and aggregates predictions from multiple RGB crops to estimate broad material-family hints and visible fabric structure before proposing an initial route, container, color group, recycling mechanism, and validation requirement. The YOLO garment-type classifier achieved 78.6% top-1 and 99.2% top-5 accuracy on the test set. The ConvNeXt-Tiny fabric-structure classifier achieved 78.55% accuracy and 78.64% macro-F1, whereas the material-family classifier achieved 56.39% accuracy and 55.83% macro-F1. In a controlled Stage 1 pilot test, binary reuse-oriented versus additional-processing routing achieved 80.0% accuracy, 75.0% precision, 75.0% recall, and an F1-score of 0.75. A Stage 2 end-to-end pilot test achieved 66.7% correctly recommended final routes, with macro-F1 of 0.767. These results provide evidence that complementary models and explicit validation rules can support preliminary explainable garment triage. However, RGB imagery cannot confirm exact fiber composition, blend percentages, or chemical contamination. Full article

In this work, to meet the requirements of high-performance electronic devices for high-frequency/speed telecommunication and semiconductor packaging, we developed a norbornene (NB)-backboned epoxy/cyanate ester compound system to modify the commercial bisphenol-A (BPA) diglycidyl ether (DGEBA) epoxy resin. A norbornene-based epoxy monomer (ENBDE) and cyanate ester (ENBCY) were synthesized using 5-ethylidene-2-norbornene (ENB) as the key starting material. The ENBDE was blended with DGEBA as the epoxy resin compound, which was cured using ENBCY as the curing agent to form a cross-linked thermoset. The effect of ENBDE content on thermal stability, mechanical properties, dielectric performance, and bonding strength of the thermosets was investigated. The optimized formula showed a significantly improved thermal stability of the cured resin with a glass-transition temperature of 249.2 °C and a 5% weight-loss temperature (T_5%) of 351.5 °C; the dielectric constant and dissipation factor at a high frequency of 10 GHz were measured to be as small as 2.57 and 0.0068, respectively, showcasing great potential as a high-performance dielectric epoxy material for high-frequency/speed electronic applications. Full article

Alveolar bone resorption after tooth extraction complicates subsequent dental implant placement. OsteoBiol^® GTO^® (Tecnoss^®, Giaveno, Italy) is an innovative pre-hydrated heterologous collagenated bone mix blended with a thermosensitive copolymer (OsteoBiol^® TSV Gel) that has demonstrated osteoconductive properties. Despite direct contact with blood vessels upon socket filling, its pro-angiogenic potential has not been directly investigated on endothelial cells. Thus, in this study, an in vitro model, consisting of the EA.hy926 endothelial cell line exposed to different OsteoBiol^® GTO^® soaking preparations [original soaking (OS), centrifuged soaking (CS), and diluted soaking (DS)] at multiple concentrations (1, 5, 10, and 20 mg/mL) was established to identify optimal experimental conditions and characterize the underlying molecular mechanisms. Cell viability and collagen release quantification led to the selection of 10 mg/mL OS as the most suitable condition. Under this condition, OsteoBiol^® GTO^® induces an early increase in Cyclooxygenase-2 (COX-2) protein expression and Prostaglandin E-2 (PGE2) secretion, followed by upregulation of Vascular Endothelial Growth Factor (VEGF) protein expression and phosphorylation of Endothelial Nitric Oxide Synthase (eNOS) at serine 1177. The tube formation assay confirmed the pro-angiogenic functional outcome. These results suggest an association between the pro-angiogenic response of endothelial cells to OsteoBiol^® GTO^® and modulation of the COX-2/PGE2/VEGF axis. This effect could be attributed to collagen accumulation in the OS, thereby representing a novel and promising pro-angiogenic mechanism with potential implications for wound healing and guided bone regeneration following tooth extraction. Full article

Water treatment sludge (WTS) is a by-product of water treatment plants, which is often landfilled and risks contaminant leakage into the environment. However, it is rich in aluminosilicate content, which suggests potential suitability as a supplementary cementitious material (SCM), offering a sustainable approach for waste recycling and carbon emission reduction in cement production. While prior reviews have broadly addressed WTS reuse across construction materials, the mechanisms governing its pozzolanic performance as a cement replacement remain insufficiently synthesized, including its emerging use in alternative binders. This systematic review addresses this gap by synthesizing literature from 2010 to 2026 on WTS as a partial cement replacement in cement-based materials (CBMs), in both binary and ternary blends. Findings show that WTS can exhibit high pozzolanic reactivity after grinding and calcination at 600–800 °C, though performance varies depending on source and composition and processing. Partial replacement of cement with 10% calcined WTS was most frequently identified as the optimal substitution level, improving mechanical properties by promoting C-S-H and C-A-S-H formation, although some studies report favourable long-term strength at higher substitution. However, most studies reported that further increasing WTS content in the mix (beyond 10%) leads to a decrease in performance due to the dilution effect, which limits the formation of C-S-H. This review further discusses the durability aspects and environmental impact of using WTS, which remain underexplored in the literature, and highlights areas for future investigations. Full article

In most African countries, supplementary cementitious materials (SCMs), such as silica fume, slag, and fly ash, are scarce, creating a need for alternative low-clinker cement that utilises locally abundant resources. Given the limited availability of SCMs, the development of Limestone Calcined Clay Cement (LC³) has emerged as an attractive solution. LC³ is a blended binder composed of ground limestone, calcined kaolinite clay, and ordinary Portland cement clinker. This research assessed the mechanical and durability properties of LC³ binders formulated using raw materials obtained from selected deposits in Tanzania. Two samples of clay from the Pugu deposit were selected: Pugu hard clay (PH) and Pugu soft clay (PS). Limestone and gypsum were sourced from Dar es Salaam. LC³ mixes containing 58% CEM I/42.5N were produced and used to make concrete with a water/binder ratio of 0.4. Two control mixes were made, a mix with 100% Portland cement CEM I/42.5 N and a mix with 100% Portland pozzolana CEM II/P-B 42.5 N. In addition, four concrete mixes were designed for the study: LC³-PH, LC³-PS, CEM I + PH (CC-PH), and CEM I + PS (CC-PS). The mechanical properties evaluated included compressive strength, splitting tensile strength, and flexural strength, whilst durability performance was assessed through sulfuric acid resistance, water sorptivity, and absorption. The results demonstrated the superiority of LC³ concrete compared to CEM I and CEM II concretes. For instance, the LC³-PS mix achieved a 90-day compressive strength of 63 ± 2.1 MPa, compared with 62 ± 1.8 MPa for CEM I. Similarly, water absorption was 1.35% and 1.1% for CEM I and LC³ concretes, respectively. Under sulfuric acid exposure, LC³ concrete exhibited the lowest mass loss (1.6%) and strength loss (17.9%) compared with 2.4% and 23% for CEM I and 2.1% and 21% for CEM II, respectively. The enhanced performance of LC³ concrete was attributed to its denser and more refined microstructure, which reduced pore connectivity and improved resistance to the ingress of aggressive agents. Full article

Cross-contamination during metal powder blending in multi-material laser powder bed fusion (PBF-LB/M) is a common production challenge and a key barrier to the wider industrial adoption of the process. In the present investigation, the effect of different CuCr1Zr foreign-particle cross-contamination rates of up to 5.0 wt.%, simulating different cross-contamination levels in an AlSi10Mg feedstock for PBF-LB/M, is examined. The resulting metallurgical features and tensile mechanical properties of the produced components were compared to those of reference specimens manufactured from uncontaminated powder. A microstructural analysis of CuCr1Zr contaminated samples revealed characteristic Cu-rich regions, demonstrating that the higher the level of cross-contamination is, the larger these regions are. Tensile yield stress is almost linearly increased with the contamination level while the opposite trend is noticed for tensile elongation at fracture. Two different stages of strain-hardening were noticed, with Stage I exhibiting a lower strain-hardening exponent, while higher strain-hardening exponents (>0.27) were noticed for Stage II, with the latter decreasing with increasing cross-contamination level. The tensile mechanical behaviour of PBF-LB/M specimens was evaluated for the first time with appropriate quality indices, which were initially developed for similar cast aluminium alloys. Overall, the quality index accounting for global tensile performance was decreased for all build directions with increasing cross-contamination level. Despite the lower quality index at the non-contamination level, the inclined (45°) printed specimens presented quality indices that were almost unaffected by the cross-contamination level. Full article

General-purpose polystyrene (GPPS) is widely used in packaging and insulation, although its recyclability poses environmental challenges that require circular economy strategies. The objective of this study was to evaluate the mechanical and tribological behavior of virgin GPPS (100%N), a 50% virgin–50% recycled blend (50N–50R), and 100% recycled GPPS (100%R), processed in Mexico under controlled injection molding conditions. Micro-tensile, flexural, surface roughness, and sliding wear (pin-on-disk) tests were conducted in accordance with ASTM/ANSI standards. The results show that virgin GPPS exhibited the highest strength (micro-tensile: 31.1 MPa; flexural: 87.8 MPa), while the 50N–50R blend maintained comparable tensile strength (27.5 MPa) with greater ductility, making it viable for secondary applications. Recycled GPPS exhibited a significant reduction in strength (micro-tensile: 18.6 MPa; flexural: 41.1 MPa), although with greater deformability. In tribological tests, the coefficients of friction were 0.480 (100%N), 0.128 (50N–50R), and 0.143 (100%R), all with relative errors of less than 4%, confirming statistical validity. Surface roughness analysis showed that the virgin material had the most uniform surface (Ra = 1.0 µm), while the blends exhibited greater variation (Ra ≈ 1.2 µm). In conclusion, although recycled GPPS has limitations compared to virgin material, it retains acceptable mechanical and tribological properties for non-structural applications. These findings support its potential in circular economy strategies in Mexico and provide a framework for countries with similar recycling infrastructure conditions. Full article

This study employs numerical simulations to systematically investigate the combustion characteristics of methane/ethanol blended fuel–air mixtures under non-premixed turbulent conditions. The effects of the methane blending ratio on the flow-field structure, flame morphology, NO emissions, and combustion efficiency are analyzed. The results show that, with increasing methane blending ratio, the recirculation mechanism gradually shifts from near-field local entrainment to far-field transport, accompanied by a reduction in local shear intensity. Methane addition enhances flame intensity, accelerates combustion, shortens flame length, mitigates heat transfer limitations, and reduces combustion delay. At the initial 10% and the final 20% of the methane blending range, the combustion process exhibits pronounced instability. Methane addition significantly suppresses NO formation, with temperature being the dominant controlling factor, while fuel composition also plays an important role. The overall combustion efficiency is improved. However, a slight decrease is observed at low blending ratios (0–0.1), and the enhancement becomes marginal when the methane blending ratio exceeds 0.6. Full article