Search Results (4,275)

A multilayer structure is a type of construction consisting of outer layers and a core, which is mainly characterized by high strength and specific stiffness, as well as the ability to dampen vibration and sound. This structure combines the high strength of traditional materials (mainly metals) and composites. Currently, sandwich structures in any configurations (types of core) are one of the main directions of technology development and research. This paper evaluates the surface quality of II- and III-layer sandwich structures that are a combination of aluminum alloy and CFRP (Carbon Fiber-Reinforced Polymer) after the machining. The effect of depth of cut (a_e) on the surface roughness of the II- and III-layer sandwich structures after the milling process was investigated. The surface homogeneity was also investigated. It was expressed by the I_Ra and I_Rz surface homogeneity indices formed from the Ra and Rz surface roughness parameters measured separately for each layer of the materials forming the sandwich structure. It was noted that the lowest surface roughness (Ra = 0.03 µm and Rz = 0.20 µm) was obtained after the milling of the II-layer sandwich structure using a_e = 0.5 mm, while the highest was obtained for the III-layer structure and a_e = 1.0 mm (Ra = 1.73 µm) and a_e = 0.5 mm (Rz = 10.98 µm). The most homogeneous surfaces were observed after machining of the II-layer structure and using the depth of cut a_e = 2.0 mm (I_Ra = 0.28 and I_Rz = 0.06), while the least homogeneous surfaces were obtained after milling of the III-layer structure and the depths of cut a_e = 0.5 mm (I_Ra = 0.64) and a_e = 2.0 mm (I_Rz = 0.78). The obtained results may be relevant to surface engineering and combining hybrid sandwich structures with other materials. Full article

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a highly promising biodegradable and bio-based thermoplastic recognized for its environmental benefits and potential versatility. However, its industrial adoption has been limited due to its inherent brittleness and suboptimal processability. Despite these challenges, PHBV’s performance can be tailored for a wide range of applications through strategic modifications, particularly by blending it with other biodegradable polymers or reinforcing it with natural fibers and bio-based fillers. This study explores the potential of brewers’ spent grain (BSG) as a sustainable source for the development of PHBV biocomposites. The biocomposites were synthesized by incorporating arabinoxylan-bound benzoate, which can be derived from BSG, as a sustainable filler at concentrations of 4% and 10% w/w. The resulting materials were characterized using tensile testing, scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). The findings demonstrate that the incorporation of functionalized arabinoxylan significantly enhances the mechanical properties of PHBV, preserves its thermal stability, and increases its crystallinity (from 59.9% to 67.6%), highlighting a positive impact on both material performance and processing characteristics. Full article

The aim of this project is to fabricate fiber mats and hydrogel materials that constitute the two main components of a wound dressing material. The contributions of boric acid (BA) and zinc oxide (ZnO) to the physical and mechanical properties of polycaprolactone (PCL) is investigated. These materials are chosen for their antimicrobial and antifungal effects. Additionally, since chitosan forms brittle hydrogels, it is reinforced with polyvinyl alcohol (PVA) to improve ductility and water uptake properties. For these purposes, PCL, BA, ZnO, PVA, and chitosan are used in different ratios to fabricate nanofiber mats and hydrogels. Mechanical, physical, and chemical characteristics are examined. The highest elastic modulus and tensile strength are obtained from samples with 6% BA and 10% ZnO concentrations. ZnO-decorated fibers exhibit a higher elastic modulus than those with BA, though BA-containing fibers exhibit greater elongation before breakage. All fibers exhibit hydrophobic properties, which help to prevent biofilm formation. In compression tests, CS12 demonstrates the highest strength. Increasing the PVA content enhances ductility, while a higher concentration of chitosan results in a denser structure. This outcome is confirmed by FTIR and swelling tests. These findings highlight the optimal combinations of nanofibrous mats and hydrogels, offering guidance for future wound dressing designs that balance mechanical strength, water absorption, and antimicrobial properties. By stacking these nanofibrous mats and hydrogels in different orders, it is expected to achieve a wound care material that is suitable for various applications. The authors encourage experimentation with different configurations of these nanofiber and hydrogel stackings to observe their mechanical behavior under real-life conditions in future studies. Full article

The demand for healthier snack options has driven innovation in frozen dairy products. This study developed and characterized novel frozen dairy snacks fermented with probiotics (Lactobacillus acidophilus LA5; Lacticaseibacillus rhamnosus GG, and Streptococcus thermophilus BIOTEC003) and containing 2% blueberry bagasse. Four formulations (LA5, LGG, LA5-BERRY, and LGG-BERRY) were analyzed for their nutritional, physicochemical, functional, and sensory properties. High protein content (>17% d.w.) and increased dietary fiber (5.77–5.88% d.w.) were observed in bagasse-containing formulations. Stable technological characteristics were maintained, with melting rates increasing slightly during storage. Probiotic viability remained high (>8.5 log CFU/mL) after freezing and storage at −20 °C for 30 days. Post-simulated digestion, probiotics retained >7.5 log CFU/mL, while blueberry bagasse formulations exhibited significantly higher phenolic content (7.62–8.74 mg/g d.w.) and antioxidant capacity, though anthocyanin content decreased (66–68%). Sensory evaluation by 100 panelists revealed high acceptance scores (>63%), with LGG-BERRY achieving the highest score (78%). These formulations demonstrate significant potential for incorporating probiotics and functional ingredients, providing an innovative solution for probiotic delivery and the sustainable utilization of fruit by-products in the food industry. Full article

This study investigates the impact of different corn silage preparation methods, namely the traditional and Shredlage methods, on digestibility and biogas yield in anaerobic digestion and its nutritional value—the first complex study of its kind. Key parameters of both silage types were analyzed, including chemical composition, fiber content, and elemental makeup. Methane and biogas production were assessed under standardized fermentation conditions. The results showed that the Shredlage method, characterized by more intensive chopping, led to higher biogas and methane yields per unit of organic dry matter compared to traditional silage. This improvement is attributed to enhanced digestibility due to the lower content of neutral detergent fiber (NDF), acid detergent fiber (ADF), and crude fiber in Shredlage. An elemental analysis revealed slight differences in carbon-to-nitrogen (C/N) ratios, with both silages showing values suitable for efficient fermentation. Despite minor variations in mineral content, Shredlage demonstrated greater efficiency in biogas production, particularly for rapid fermentation processes. The findings underscore the importance of silage preparation techniques in optimizing biogas yield and suggest Shredlage as a superior option for enhancing energy recovery in biogas plants. Future work should explore the economic trade-offs and scalability of these methods. Full article

Radiofrequency ablation (RFA) is a minimally invasive procedure that utilizes localized heat to treat tumors by inducing localized tissue thermal damage. The present study aimed to evaluate the temperature evolution and spatial distribution, ablation size, and reproducibility of ablation zones in ex vivo liver, kidney, and lung using a commercial device, i.e., Dophi™ R150E RFA system (Surgnova, Beijing, China), and to compare the results with the manufacturer’s specifications. Optical fibers embedding arrays of fiber Bragg grating (FBG) sensors, characterized by 0.1 °C accuracy and 1.2 mm spatial resolution, were employed for thermometry during the procedures. Experiments were conducted for all the organs in two different configurations: single-electrode (200 W for 12 min) and double-electrode (200 W for 9 min). Results demonstrated consistent and reproducible ablation zones across all organ types, with variations in temperature distribution and ablation size influenced by tissue characteristics and RFA settings. Higher temperatures were achieved in the liver; conversely, the lung exhibited the smallest ablation zone and the lowest maximum temperatures. The study found that using two electrodes for 9 min produced larger, more rounded ablation areas compared to a single electrode for 12 min. Our findings support the efficacy of the RFA system and highlight the need for tailored RFA parameters based on organ type and tumor properties. This research provides insights into the characterization of RFA systems for optimizing RFA techniques and underscores the importance of accurate thermometry and precise procedural planning to enhance clinical outcomes. Full article

Electrospinning is a versatile technique for obtaining nano/micro fibers which are able to significantly change the active properties of composite materials and bring in new dimensions to agri-food applications. Composite bio-based packaging materials obtained from whey proteins, functionalized with thyme essential oil (TEO) and reinforced by electrospun polylactic acid (PLA) fibers, represent a promising solution for developing new active food packaging using environmentally friendly materials. The aim of this study is to obtain and characterize one-side-active composite films covered with a PLA fiber mat: (i) WF/G1, WF/G2, and WF/G3 resulting from electrospinning with one needle at different electrospinning times of 90, 150, and 210 min, respectively, and (ii) WF/G4 obtained with two face-to-face needles after 210 min of electrospinning. While TEO bioactivity is mainly related to its antimicrobial and antioxidant properties, the PLA fiber mat uplifted the composite mechanical and barrier properties of films. The bi-layer films obtained were characterized by SEM, showing the distribution of the electrospun fiber mat and an increased thickness of the PLA layer from WF/G1 to WF/G4, while FTIR spectra showed the structural vibrations of the functional groups. The experimental results show that WF/G4 have a FTIR fingerprint resembling PLA, retained ~50% of the volatile compounds present in the uncovered film (WF/TEO), while it only had 1.41 ± 0.14 (%) of the permeability to octanol of the WF/G1 film. WF/G4 exhibited 33.73% of the WVP of WF/G1 and displayed the highest tensile strength, about 2.70 times higher than WF/TEO. All films studied revealed similar antimicrobial effect against Bacillus cereus, Geotrichum candidum, and Rhodotorula glutinis and good antiradical activity, thus demonstrating good prospects to be applied as food packaging materials. WF/G composite materials are good candidates to be used as bioactive flavoring primary packaging in hard cheese making. Full article

The increasing application of fiber-reinforced polymer (FRP) composites necessitates the development of composite structures that exhibit high stiffness, high strength, and favorable failure behavior to endure complex loading scenarios and improve damage tolerance. Achieving these properties can be facilitated by integrating conventional FRPCs with metallic materials, which offer high ductility and superior energy absorption capabilities. However, there is a lack of effective solutions for the micro-level hybridization of high-performance filament yarns, metal filament yarns, and thermoplastic filament yarns. This study aims to investigate the hybridization of multi-material components at the micro-level using the air-texturing process. The focus is on investigating the morphological and the mechanical properties as well as the damage behavior in relation to the process parameters of the air-texturing process. The process-induced property changes were evaluated throughout the entire process, starting from the individual components, through the hybridization process, and up to the tape production. Tensile tests on multifilament yarns and tape revealed that the strength of the hybrid materials is significantly reduced due to the hybridization process inducing fiber damage. Morphological analyses using 3D scans and micrographs demonstrated that the degree of hybridization is enhanced due to the application of air pressure during the hybridization process. However, this phenomenon is also influenced by the flow movement of the PP matrix during the consolidation stage. The hybrid laminates exhibited a damage behavior that differs from the established behavior of layer-separated metal fiber hybrids, thereby supporting other failure and energy absorption mechanisms, such as fiber pull-out. Full article

This study presents a novel reflective fiber Fabry–Perot (F–P) salinity sensor. The sensor employs a femtosecond laser to fabricate an open liquid cavity, facilitating the unobstructed ingress and egress of the liquid, thereby enabling the direct involvement of the liquid in light transmission. Variations in the refractive index of the liquid induce corresponding changes in the effective refractive index of the optical path, which subsequently influences the output spectrum. The dimensions and quality of the optical fiber are meticulously regulated through a combination of femtosecond laser cutting and chemical polishing, significantly enhancing the mechanical strength and sensitivity of the sensor’s overall structure. Experimental results indicate that the sensor achieves salinity sensitivity of 0.288 nm/% within a salinity range of 0% to 25%. Furthermore, the temperature sensitivity is measured at a minimal 0.015 nm/°C, allowing us to neglect temperature effects. The device is characterized by its compact size, straightforward structure, high mechanical robustness, ease of production, and excellent reproducibility. It demonstrates considerable potential for sensing applications in the domains of biomedicine and chemical engineering. Full article

As animal husbandry advances, the demand for premium feed has seen substantial growth, while the availability of natural forage resources remains limited. Corn stover, characterized by its high yield and rich nutritional content, has become a vital source of roughage. The application of silage technology to corn stover enhances its palatability, improves its nutritional value, and exerts positive effects on livestock production performance. This study aims to evaluate the impact of different additives and their proportions on the nutrient composition, fermentation quality, and microbial community structure of corn stover silage. Specifically, Lactobacillus plantarum, cellulase preparations (commercial cellulase enzyme preparations), and xylanase preparations (commercial xylanase enzyme preparations) were employed as additives to investigate their synergistic effects and underlying mechanisms during the silage process. Furthermore, dosage gradients were established to determine the optimal dosage range, providing a robust scientific basis for the optimization of additive applications. In this experiment, corn stover was used as the substrate, with the moisture content maintained at 60%. Treatments with Lactobacillus plantarum, cellulase, and xylanase were applied, and silage samples were analyzed after 30 and 60 days of fermentation to assess fermentation quality, nutritional quality, and microbial community structure. The findings revealed that the nutritional quality of corn stover silage improved progressively with fermentation time. Compared to the control group, the addition of Lactobacillus plantarum, cellulase, and xylanase significantly increased the abundance of lactic acid bacteria, reduced the pH value, and effectively suppressed the proliferation of spoilage microorganisms. Among the treatments, xylanase demonstrated the most pronounced effects, substantially increasing lactic acid and soluble carbohydrate content while reducing levels of neutral detergent fiber (NDF) and acid detergent fiber (ADF). Notably, the incorporation of 20 U/g xylanase into the silage process facilitated the breakdown of xylan in corn stover into soluble carbohydrates, thereby providing essential substrates for lactic acid bacteria and other beneficial microorganisms. This, in turn, inhibited the growth of harmful microorganisms, ultimately improving the nutritional quality, fermentation quality, and microbial community structure of the silage. These findings provide a theoretical framework and practical guidance for optimizing the production of corn stover silage, promoting efficient resource utilization, and supporting the sustainable development of animal husbandry. Full article

Carbon Fiber Reinforced Polymers (CFRPs) are extensively utilized in civil engineering and other domains due to their exceptional mechanical properties. Integrating CFRPs with steel presents an approach to structural design, characterized by enhanced load-bearing capabilities and extended service life. Static tensile and hysteretic tests were employed to examine the influence of the bolt diameter and steel plate thickness on the shear resistance of component. The results indicate that under monotonic loading, the load–displacement curves for each component undergo three distinct phases: the linear stage, damage evolution stage, and failure stage, ultimately leading to a bolt pull-off failure in all six groups of components. Under cyclic loading, the component with a 1.5 mm thick steel plate and a 4.6 mm diameter bushing bolt experienced bolt shear failure, primarily caused by the increased steel plate thickness, which enhanced the component’s load-carrying capacity, ultimately leading to the overloading and failure of the M4 bolt. The other five groups of components experienced pull-off failures. The hysteresis curve analysis revealed that enhancements in steel plate thickness and bolt diameter improve the hysteresis behaviour of the connections. However, there was a significant reduction in the strength degradation coefficient and hoop stiffness, which decreased to approximately 55% and 40% of their initial values, respectively. Full article

This study aimed to investigate the effect of adding bamboo fiber on the basic physical properties of gluten-free and low-carbohydrate bread. The control bread was made from buckwheat, flax, and walnut flour. Bamboo fiber was introduced to the bread recipe in proportions ranging from 0 to 10% (every 2%). The results showed that adding from 4 to 6% bamboo fiber to the control bread resulted in a slight rise of around 3% in volume, but a larger addition resulted in a drop in volume. The pH changes were also not significant; after more than 6% addition, the pH increased by about 2%. After adding more than 4% fiber, the color of the crumb changed noticeably (∆E >3), owing mostly to a significant increase in the lightness (L*) coefficient. The incorporation of the fiber had the greatest impact on the textural parameters when the storage time was increased to 48 h. The addition of 6% fiber resulted in unfavorable alterations in the hardness. In conclusion, our findings demonstrate that bamboo fiber can serve as a beneficial component for enriching gluten-free and low-carbohydrate bread, but its proportion should not exceed 4%. This developed bread with 4% addition of bamboo fiber can be classified as a functional bread for special diets; in addition to its very low carbohydrate content (15.3%), it was also characterized by a high fiber content (12.2%) and a low caloric value (176.7 kcal/100 g FM). Full article

Disentangled ultra-high-molecular-weight polyethylene (d-UHMWPE) solves the problem of the difficult processing of traditional UHMWPE caused by entanglements between molecular chains. In this review, we look into the innovative realm of nascent disentangled UHMWPE, concentrating on the recent advances achieved through the in situ polymerization of ethylene by single-site catalysts. The effect of single-site catalysts and polymerization conditions on the molecular characteristics is discussed in detail from the perspective of mechanism and DFT calculations. The key factors to low entanglement are revealed, which have instructive implications for the development of new single-site catalytic systems that can generate d-UHMWPE more efficiently and become closer to industrial production. The progress in the preparation for nascent d-UHMWPE with homogeneous and heterogeneous single-site catalysts is systematically reviewed. Rheology and DSC can be used to characterize the degree of entanglement. High-modulus and high-strength biaxial films, tapes, and fibers are obtained by the solid-state processing of these nascent d-UHMWPE. Full article

Introduction: Familial hypercholesterolemia (FH) is a genetic disorder that remains underdiagnosed and undertreated. It is characterized by high levels of low-density lipoprotein cholesterol (LDL-C), which leads to an increased cardiovascular disease risk. Pharmacotherapy of FH is based on high-dose statin therapy, often combined with ezetimibe and proprotein convertase subtilisin/kexin 9 inhibitors. The dietary approach is an important and supportive part of FH management. Methods: This review aimed to present the available evidence on dietary strategies in FH patients. The analyzed aspects included macronutrients such as fat and carbohydrate intake, as well as the role of dietary fiber, nutraceuticals (omega-3, beta-glucan, phytosterols, and red yeast fermented rice extract), and overall dietary models. Results and Conclusions: Based on the available data, the Mediterranean diet is a dietary model advised in cardiovascular prevention, including patients with FH. Regarding detailed recommendations, the current state of knowledge indicates dietary fat and saturated fatty acids intake limitation as an advised strategy. Supplementation of phytosterols and fiber can be also helpful in FH. Full article

Cleavable bio-based epoxy resin systems are emerging, eco-friendly, and promising alternatives to the common thermoset ones, providing quite comparable thermo-mechanical properties while enabling a circular and green end-of-life scenario of the composite materials. In addition to being designed to incorporate a bio-based resin greener than the conventional fully fossil-based epoxies, these formulations involve cleaving hardeners that enable, under mild thermo-chemical conditions, the total recycling of the composite material through the recovery of the fiber and matrix as a thermoplastic. This research addressed the characterization, processability, and recyclability of a new commercial cleavable bio-resin formulation (designed by the R-Concept company) that can be used in the fabrication of fully recyclable polymer composites. The resin was first studied to investigate the influence of the different post-curing regimes (room temperature, 100 °C, and 140 °C) on its thermal stability and glass transition temperature. According to the results obtained, the non-post-cured resin displayed the highest T_g (i.e., 76.6 °C). The same post-curing treatments were also probed on the composite laminates (glass and carbon) produced via a lab-scale vacuum-assisted resin transfer molding system, evaluating flexural behavior, microstructure, and dynamic-mechanical characteristics. The post-curing at 100 °C would enhance the crosslinking of polymer chains, improving the mechanical strength of composites. With respect to the non-post-cured laminates, the flexural strength improved by 3% and 12% in carbon and glass-based composites, respectively. The post-curing at 140 °C was instead detrimental to the mechanical performance. Finally, on the laminates produced, a chemical recycling procedure was implemented, demonstrating the feasibility of recovering both thermoplastic-based resin and fibers. Full article