Search Results (152)

This study investigates the quasi-static equalbiaxial compression behavior of 3D-printed Miura-ori metamaterials incorporating both out-of-plane and in-plane gradient configurations. The Miura-ori structure, composed of tessellated parallelogram units, exhibits pronounced anisotropic behavior due to its unique folding geometry. To assess this behavior, specimens were fabricated using ABS resin and subjected to equalbiaxial compression in three orthogonal directions: the xy-direction (in-plane compression), the yz-direction (edge-on side loading), and the xz-direction (accordion-like profile loading). In the out-of-plane gradient design, the acute angle ϕ was varied across layers, significantly influencing both yield stress and specific energy absorption (SEA). Compared with the uniform design, gradient configurations exhibited reduced mechanical performance in the xy-direction and yz-direction, and enhanced properties in the xz-direction. In addition, in-plane (x-direction) gradient structures were evaluated under xy-, yz- and xz- direction compression. The results indicate that gradient configuration specimens exhibit significantly lower yield stress and specific energy absorption than uniform structure specimens, with deformation initiating preferentially in regions with smaller acute angles and lower local stiffness. The results highlight the strong influence of geometric gradation and loading direction on the mechanical performance of Miura-ori metamaterials. This work provides new insights into the design and optimization of origami-inspired energy-absorbing structures for use in advanced mechanical, aerospace, and protective engineering applications. Full article

(Fe/C)/ABS resin electromagnetic metamaterials were fabricated via 3D printing, and the effect of iron salt loading (0, 1, 2, and 3 g) in the Fe/C filler on the microwave absorption performance of the resulting composites was systematically investigated. The results demonstrate that, with increasing iron salt content, the microwave absorption bandwidth of the samples exhibits a trend of initial significant broadening followed by saturation. At an iron salt loading of 1 g, the (Fe/C)/ABS resin composite achieves an effective absorption bandwidth (EAB) of 6.2 GHz at a matching thickness of 10 mm, representing an approximately 48% enhancement over that of the pure C/ABS resin composite (4.2 GHz). The incorporation of iron salts not only endows the material with magnetic loss capability but also promotes the formation of an sp²-hybridized carbon framework within the carbon matrix during Fe/C composite preparation, concurrently introducing abundant defect sites that augment the dielectric loss capacity. Under the synergistic magneto-dielectric loss mechanism, the microwave attenuation coefficient of the material is markedly enhanced, and the effective absorption bandwidth is substantially broadened, all at a filler loading of merely 2.5 wt%. This study elucidates the influence of iron salt loading on the microwave absorption performance of (Fe/C)/ABS resin composites, while the 3D printing-based fabrication approach employed herein offers a promising technical pathway for the development of novel microwave-absorbing materials. Full article

Almond processing byproducts are rich in bioactive polyphenols but severely underutilized due to inefficient conventional extraction methods. This study presents the first systematic optimization of an integrated ultrasound-assisted enzymatic extraction and AB-8 macroporous resin purification process for almond hull polyphenols, addressing the limitations of low yield, high impurity content, and bioactivity loss in traditional approaches. Extraction parameters were optimized via single-factor experiments combined with Box–Behnken response surface methodology, while purification conditions were refined through static and dynamic adsorption–desorption tests. Structural characterization and antioxidant evaluation were performed using Ultraviolet-Visible Spectroscopy (UV-Vis), Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and Ferric Reducing Antioxidant Power (FRAP) assays. Under optimal conditions, the polyphenol yield reached 23.67 mg/g. After purification, polyphenol purity increased 5.88-fold, flavonoid purity improved 4.62-fold, and DPPH/FRAP antioxidant activities were enhanced 5.0-fold and 6.5-fold, respectively. Purified polyphenols retained intact phenolic structures and exhibited a loose porous microstructure. This green process provides a technical basis for high-value utilization of almond hulls. Limitations include lack of polyphenol monomer identification, in vivo efficacy validation and industrial economic feasibility assessment. Full article

Vicia villosa Roth is an excellent green manure crop and offers promising applications in green agricultural production and bioactive substance exploitation. In this study, crude polysaccharides (VVP) were prepared from V. villosa using water extraction and alcohol precipitation. Single-factor experiments combined with Box–Behnken response surface methodology were employed to optimize the decolorization process of VVP with AB-8 macroporous resin. The optimal conditions were determined as follows: a resin-to-sample ratio of 1:140 (m/m), decolorization temperature of 78 °C, and a decolorization time of 300 min. Under these conditions, the decolorization rate reached 67.36% and the polysaccharide retention rate was 61.85%, with a relative error of only 2.1% between the model-predicted and experimental values. In vitro antioxidant assays showed that VVP possessed strong antioxidant activity. At a concentration of 2 mg/mL, the DPPH radical scavenging rate of VVP was 91.9%, and the ABTS+ radical scavenging rate reached 96% at 8 mg/mL. Moreover, VVP promoted crop growth and markedly alleviated the inhibition of salt stress on root development. To the best of our knowledge, this is the first report demonstrating that V. villosa crude polysaccharide extract simultaneously possesses strong antioxidant activity, salt-stress alleviation capacity, and plant growth-promoting effects, highlighting their potential as natural antioxidants and agricultural biostimulants. Full article

Organic residues were extracted from ten amphorae recovered during excavations at the Late Roman Villa del Tellaro (Noto, Sicily). The samples were analysed using liquid chromatography coupled to a high-resolution Orbitrap mass spectrometer (LC-MS). Biomarkers of plant oils, including saturated and unsaturated fatty acids (oleic, linoleic, palmitic, stearic) and the oxidation product azelaic acid, were identified in eight samples. Wine-compatible biomarkers (syringic acid, L-proline, malic acid), albeit in the absence of tartaric acid, were detected in two samples alongside the oil markers, a pattern that would be consistent with, though not in itself proof of, amphora reuse. Two further samples yielded a more saturated, degraded fatty-acid profile most parsimoniously interpreted as a strongly degraded plant oil, although a contribution of animal or fish fat (possibly garum) cannot be excluded on the fatty-acid data alone. Diterpenoid resin acids diagnostic of Pinaceae spp. pitch (dehydroabietic acid, 7-oxo-DHA, 15-hydroxy-7-oxo-DHA) were identified in all ten samples, confirming the systematic application of pine resin coatings. The assemblage comprises mainly North African types (Tripolitana II, Tripolitana III, Keay 35A/B, Keay 62Q) alongside one Eastern Mediterranean amphora (LRA8) and unidentified forms. The results offer the first archaeometric evidence for the contents of transport amphorae from the Villa del Tellaro, contributing new data on Late Antique trade between North Africa, the Eastern Mediterranean, and southeastern Sicily. Full article

To exploit medicinal and edible plant resources, this study investigated the extraction, structural characterization, and in vitro digestion of Elaeagnus angustifolia polysaccharide (EAP). Despite the nutritional value of this polysaccharide, its digestive properties remain unclear. Ultrasound-assisted extraction was optimized via response surface methodology. Crude EAP was purified by AB-8 macroporous resin purification and decolorization, followed by deproteinization and dialysis. The purified product (91.07% total sugar; 2.37% protein) was characterized by ultraviolet (UV) spectroscopy, Fourier-transform infrared (FT-IR) spectroscopy, high-performance liquid chromatography (HPLC), and gel permeation chromatography (GPC), and its digestion profile was assessed using a three-stage in vitro model (INFOGEST 2.0). Under optimal conditions, the crude polysaccharide yield (based on ethanol-precipitated solid; 87.83% total sugar) reached 2.44 ± 0.01%. EAP was identified as a pyranose-type polysaccharide, with glucose, mannose, and galactose as the predominant monosaccharides (relative molar proportions, 0.470:0.199:0.081, normalized to the total detected monosaccharides), with a weight-average molecular weight of 1.739 × 10⁵ g·mol⁻¹. In vitro digestion revealed negligible digestibility in the oral phase (0%), and low digestibility in the gastric (0.55%) and intestinal (2.76%) phases, with a cumulative digestibility of 3.30%. This marked resistance to gastrointestinal digestion indicates EAP is a partially digestible polysaccharide with potential prebiotic properties. The demonstrated resistance to gastrointestinal breakdown provides a theoretical basis for the high-value utilization of EAP in functional foods as a potential fermentable substrate for gut microbiota modulation. Full article

Ionic liquid-assisted extraction can improve the recovery of monoterpene glycosides from Radix Paeoniae Alba, whereas post-extraction purification and ionic-liquid-associated marker-level quality control remain necessary before further bioactivity evaluation. In this study, a macroporous resin-based purification process was developed for monoterpene glycoside-enriched extracts obtained by conventional reflux extraction and ionic liquid-assisted microwave–ultrasound extraction. Among the five tested resins, AB-8 resin showed the best adsorption performance and was selected for further process optimization. The optimized purification conditions were a loading concentration of 13 mg/mL, loading pH of 7, elution with 70% ethanol, loading volume of 6 BV and elution volume of 9 BV. After purification, the total quantified monoterpene glycoside content increased from 6.59% to 51.68% in the conventional extract and from 15.30% to 75.30% in the ionic liquid-assisted extract. The ionic-liquid-associated elemental marker content in the ionic liquid-assisted extract decreased from 5.593% to 0.072% after purification, corresponding to an approximately 98.7% reduction at the elemental-marker level. Stability evaluation indicated that Na₂SO₃, Fe³⁺, ascorbic acid, sucrose and light exposure affected the detected monoterpene glycoside content to different extents, whereas short-term heating within 20–80 °C caused only slight fluctuations. The purified extracts showed stronger DPPH and ABTS radical scavenging activities and reducing power than the crude extracts. In LPS-stimulated RAW264.7 cells, the purified extracts reduced NO production and downregulated the mRNA expression of IL-6, IL-1β, TNF-α, iNOS and COX-2, suggesting anti-inflammatory potential at the NO and gene-expression levels. AB-8 resin purification enriched the monitored monoterpene glycosides, reduced the selected ionic-liquid-associated elemental marker, and generated purified fractions suitable for subsequent stability and bioactivity evaluation. Full article

Recycled thermoplastics offer a promising route for valorizing industrial residues and developing thermoplastic-bonded wood-based panels without added formaldehyde-based resins. In this study, experimental wood–polymer composite boards were produced from recycled acrylonitrile–butadiene–styrene (ABS) edge-banding waste used as the polymer matrix and industrial wood fibers used as the lignocellulosic reinforcement. The boards were manufactured at target densities of 800–1200 kg·m⁻³ and wood fiber contents of 10–30%, followed by the evaluation of selected physical and mechanical properties, including water absorption, thickness swelling, modulus of elasticity and bending strength. Thermogravimetric analysis of the recycled ABS edge-banding material and qualitative optical microscopy of the board surfaces were used to support, but not independently prove, the interpretation of the composite structure. The recycled ABS waste enabled the formation of compact boards, with density exerting the strongest influence on water resistance and bending performance. The regression models indicated a balanced region at 21.84 wt.% wood fibers and 1134 kg·m⁻³, corresponding to predicted water absorption of 1.62%, thickness swelling of 3.22%, modulus of elasticity of 2931 N·mm⁻² and bending strength of 22.20 N·mm⁻². Optical microscopy suggested a more continuous ABS-rich surface in the most homogeneous specimens, whereas local accumulations of fine particles and areas of limited polymer coverage were observed on the opposite surface. These findings demonstrate the potential of recycled ABS edge-banding waste for wood–polymer board production, while indicating that additional feedstock cleaning and sieving should be investigated in subsequent work to improve furnish uniformity and structural homogeneity. Full article

The recycling of acrylonitrile-butadiene-styrene (ABS) is crucial for a circular plastics economy, but repeated extrusion induces degradation that limits its reuse. This study establishes a comprehensive structure-property evolution mechanism for ABS 757K over five extrusion cycles and develops a novel image-recognition model for aging degree prediction. Multi-faceted characterization revealed that chain scission, oxidation of the polybutadiene (PB) phase, and the formation of chromophores led to progressive embrittlement, yellowing, and reduced thermal-oxidative stability. A key finding from Energy Dispersive Spectroscopy (EDS) was the stability and homogeneous distribution of sulfur-based antioxidants, which underpin the material’s superior resistance to degradation by effectively scavenging free radicals, which function as effective free radical scavengers. This mechanism underpins the material’s superior resistance to thermo-oxidative degradation. Consequently, significant molecular weight reduction and property deterioration were delayed until later extrusion cycles. Furthermore, a deep learning model based on the DeepLabV3+ architecture was trained to predict extrusion history directly from scanning electron microscopy (SEM) images of impact-fractured surfaces. The model achieved an average prediction accuracy exceeding 96.5%. Remarkably, it demonstrated excellent generalizability, maintaining high accuracy on two unseen commercial ABS grades. This indicates that the micro-morphological evolution pathway is a universal fingerprint of thermo-mechanical aging in ABS. This work not only elucidates the multi-scale degradation mechanism of recycled ABS but also provides a rapid, non-destructive tool for intelligent quality assessment in plastic recycling streams, bridging advanced machine learning with practical sustainability challenges. Full article

The scientific literature lacks sufficient data on the transport of various toxic pollutants by polymer particles. Investigating how the structure of microplastic particles formed during the degradation of polymeric materials affects pollutant sorption processes will improve our ability to predict environmental behavior. General-purpose polystyrene, expanded polystyrene, ABS plastic (acrylonitrile–butadiene–styrene) and crosslinked polystyrene are produced on an industrial scale. Copolymers of styrene with divinylbenzene are used on a large scale as sorbents for gel permeation chromatography (Styragel brand sorbents), in the production of catalysts on a polymer substrate or ion-exchange resins. In this study, non-spherical, crosslinked polystyrene microparticles with varying polystyrene chain packing densities were used as model microplastic particles representative of crosslinked polystyrene. It was shown that the adsorption of a hazardous chemical rhodamine B was influenced by both the packing density of the polystyrene chains and the presence of ionic functional groups, i.e., the “degree of aging” of the microplastic particles. The sorption capacities of these model microparticles were compared with those of natural origin (silicon dioxide, quartz powder, and microcrystalline cellulose). A viability assay using HEK293 and HeLa cell lines exposed to leachates from both pristine and rhodamine B-loaded microparticles revealed that all unmodified microparticles, regardless of their nature, exhibited no cytotoxicity at concentrations up to 1000 μg/mL. In contrast, microparticles with adsorbed rhodamine B significantly reduced cell viability to 20–40% at concentrations of 100 μg/mL. Full article

In this study, 20% ethanol elution fraction(PC-20), 40% ethanol elution fraction(PC-40), 60% ethanol elution fraction(PC-60), and 80% ethanol elution fraction (PC-80)of Penthorum chinense polyphenols were obtained using AB-8 macroporous resin . Their in vitro bioactivities were compared to explore potential applications. A comprehensive phytochemical analysis identified 85 compounds, including 16 phenolic acids, 36 flavonoids, 24 hydrolyzed tannins, 7 anthocyanins, and 2 others. The results showed clear ethanol concentration-dependent variations in both compound composition and bioactivity. PC-20 had the highest levels of total polyphenols (418.45 mg/g), proanthocyanidins (84.95 mg/g), and tannins (10.61 mg/g), and also showed the best antioxidant capacity. PC-40 contained the most flavonoids (227.55 mg/g). PC-60 gave the strongest α-glucosidase inhibition (IC₅₀ = 0.79 µg/mL), while PC-20 was most effective against pancreatic lipase (IC₅₀ = 101.06 µg/mL) and also significantly activated the enzymes ADH and ALDH. Overall, PC-20 appears more suitable for applications aimed at antioxidant, anti-obesity, or liver-protective effects, whereas PC-60 is more promising for blood glucose control. This work provides a practical basis for selecting different ethanol fractions of P. chinense polyphenols according to specific functional needs. Full article

This paper examines how forest by-products (potash, tar, resin and charcoal—PoTaRCh), with a special focus on charcoal production, are presented in contemporary heritage tourism and how different communication frameworks influence the audience’s perceptions and intentions in the context of low-carbon development. The research is based on a combined methodological approach. Qualitative analysis of 70 communication units from the field of heritage tourism identified three dominant communication frames: traditional heritage, ecological-educational frame and future-oriented low-carbon innovation. These findings served as the basis for the experimental part of the research, conducted through an online A/B test on a sample of 212 adult respondents interested in travel, cultural tourism and heritage-based experiences. The results of the experiment indicate that the low-carbon communication framework leads to statistically significantly higher levels of perceived relevance of PoTaRCh, visit intention and positive attitude towards sustainability compared to the traditional framework, with perceived relevance partially mediating these effects. The findings suggest that, although traditional communication patterns still dominate heritage tourism, the future-oriented low-carbon framework shows greater communication potential for attracting a sustainability- and future-oriented audience. By combining the analysis of communication content from several European countries and the experimental testing of communication frameworks, the research provides an empirical contribution to the understanding of the transition from the concept of heritage-as-preservation to heritage-as-transition in contemporary discourses of sustainable tourism. Full article

To address heavy metal contamination in wastewater, this study developed a novel chelating resin (PS-2-AB) by grafting 2-aminobenzimidazole onto chloromethylated polystyrene. The resin was characterized using SEM, BET, FTIR, and XPS to confirm successful modification and analyze its structural properties. Batch adsorption tests were conducted to evaluate its removal performance for Cu(II) and Ni(II) ions. Under optimal conditions (pH 5.0–7.0, dosage: 1.0 g/L), PS-2-AB achieved maximum adsorption capacities of 125.04 mg/g for Cu(II) and 157.44 mg/g for Ni(II), which are significantly higher than those of the commercial resin D113 (44.68 mg/g for Cu(II) and 25.17 mg/g for Ni(II)) under the same conditions. Adsorption kinetics followed the pseudo-second-order model, indicating chemisorption-dominated behavior, while equilibrium data fit the Langmuir model, suggesting monolayer adsorption. Thermodynamic parameters confirmed a spontaneous and endothermic process. After five regeneration cycles, PS-2-AB retained approximately 87% (Cu) and 89% (Ni) of its original capacity, demonstrating good reusability. These results indicate that PS-2-AB exhibits markedly better adsorption performance than D113, making it a promising and cost-effective adsorbent for the efficient removal of Cu(II) and Ni(II) from aqueous media. Full article

Depletion of reserves of rich copper–porphyry ore deposits necessitates the development of highly efficient methods for Mo (VI) extraction from complex, corrosive hydro-metallurgical media. The present study undertakes a comprehensive assessment of sorptive concentration of Mo (VI) from strongly acidic sulfate solutions (120 g/L H₂SO₄) by employing a spectrum of commercially available strong- and weak-base anion-exchange resins. It has been established that the macroporous weak-base anion exchanger Purolite A-100 demonstrates decisive superiority over gel-type analogs (Lewatit M-800, AB-17), facilitating unimpeded intra-gel diffusion of bulky molybdenyl sulfato-complexes anions, thereby circumventing the obstructive “sieve effect.” Thermodynamic and kinetic investigations revealed that the sorption process exhibits pronounced concentration- and pH-dependent characteristics. Peak extraction efficiency (up to 95.91%) is achieved at pH ≈ 1, a finding that correlates with the region of maximal protonation of tertiary amino groups within the resin matrix. Kinetic acceleration of mass transfer upon heating to 80 °C has been experimentally confirmed, yielding 94.6% extraction within 60 min. The obtained results corroborate the prospective integration of macroporous weak-base anion exchangers into operational hydro-metallurgical schemes as an environmentally benign and efficacious alternative to conventional solvent extraction of molybdenum. Full article

Polymer blends constitute a strategy for tailoring the properties of commercial polymers, leading to the development of materials designed for specific applications. In this work, the effect of the mixing sequence of the reactive compatibilizer styrene–acrylonitrile functionalized with epoxy groups (SAN-g-Epoxy) on the performance of poly(butylene terephthalate) (PBT)/acrylonitrile–butadiene–styrene (ABS) blends was investigated. PBT/ABS blends (60/40 wt%) were prepared by reactive extrusion in a twin-screw extruder followed by injection molding, incorporating five parts per hundred resin (phr) of SAN-g-Epoxy through different mixing sequences, aiming to understand how the processing order influences interfacial reactions, morphology, and the final properties of the material. The results indicated that SAN-g-Epoxy promotes reactive compatibilization between PBT and ABS, as evidenced by a significant increase in torque and complex viscosity, as well as by an increase in the intensity of the carbonyl band in the Fourier transform infrared spectroscopy (FTIR) spectra. By scanning electron microscopy (SEM), the presence of the compatibilizer resulted in a pronounced morphological refinement of the dispersed ABS phase, reducing the average particle size from approximately 4.34 µm to about 0.47–0.54 µm. Among the processing strategies, the route (PBT/SAN-g-Epoxy) + ABS exhibited the best mechanical performance under impact, reaching 206.7 J/m. However, the simultaneous mixing sequence PBT/ABS/SAN-g-Epoxy showed the best balance of properties, with gains of 203% in impact strength, 8.8% in elastic modulus, and 40.1% in heat deflection temperature (HDT) compared to neat PBT. The results indicate that PBT can be improved and tailored for engineering applications. Full article