Search Results (248)

The paper industry is always looking for possible solutions for new fiber-based products, such as protective and cushioning materials. These materials must be carefully designed to provide effective cushioning while also being lightweight to reduce transportation costs. Additionally, they need to offer protection from environmental and mechanical damage, besides having good processability to ensure proper buffering. The widely used protective and cushioning materials, such as plastic foams and expanded or extruded polystyrene, create significant disposal challenges. Therefore, there is increasing demand for biodegradable and sustainable materials for cushioning applications. The focus of our research was to develop fiber-based foams and investigate the influence of different compositions (hardwood and softwood) of cellulose fibers on the basic (mass, thickness, density) and mechanical properties (three-point bend test, tensile properties). Foams made entirely from short eucalyptus fibers (100S) exhibited the highest density (28.0 ± 0.34 kg/m³) and lowest thickness (38.82 ± 4.21 mm), resulting in superior tensile strength and elastic modulus but lower strain at break. In contrast, foams composed of long spruce fibers (100L) had the lowest density (19.0 ± 0.27 kg/m³) and highest thickness (58.52 ± 1.50 mm), with lower strength and stiffness but much higher ductility and porosity (confirmed by ~30% higher air permeability compared to 100S). Blended formulations demonstrated intermediate behavior, with the 50S50L foam showing a favorable balance of strength, stiffness, and flexibility. Visual analysis confirmed heterogeneous fiber distribution with localized agglomerates and compaction at the bottom layer due to casting. To further interpret the complex relationships within the dataset and uncover patterns, Principal Component Analysis (PCA) was applied to all experimental results. The findings of the research contribute to the broader understanding of how different fiber types and blends impact the performance of sustainable cellulose-based foams, with potential implications for the development of biodegradable packaging and lightweight construction materials. Full article

Airdropped equipment is important for cargo delivery and battlefield support. However, its development is constrained by the harsh conditions of high-altitude environments. To address the issues of low cushioning efficiency and instability of airdropped equipment in high-altitude environments, this study proposes a combined airbag system designed for the landing cushioning of heavy airdropped equipment under high-altitude and low-pressure conditions. A cylindrical side airbag and its folding–deployment scheme were developed. The cushioning performance of the proposed combined airbag was compared with that of a conventional airbag under two typical conditions. The effects of vent orifice opening pressure, vent orifice area, and main airbag height on cushioning performance were analyzed, along with their influence on the peak deceleration of the equipment. The airdrop environmental adaptability under complex interactive environments was evaluated through the Monte Carlo surrogate model method. The results indicate that the proposed combined airbag exhibits superior cushioning performance in high-altitude, low-pressure environments, reducing the peak deceleration by 44.9% and 50% under the two conditions. As the height of the main airbag increases, the peak overload of the equipment progressively decreases. In contrast, as the vent orifice area increases, the peak overload initially decreases and then increases. When the main airbag height is 1.35 m and the vent orifice area is 0.4 m², the system achieves the best damping performance and landing stability at a 4500 m altitude environment. The overall airdrop success rate reaches 93.33% across various complex environments. This study provides a viable solution to meet the airdrop requirements of heavy equipment in high-altitude environments. Full article

Heat treatment is a critical intermediate process in copper strip manufacturing, where strips go through an air-cushion annealing furnace. The production scheduling for the air-cushion annealing furnace can contribute to cost reduction and efficiency enhancement throughout the overall copper strip production process. The production scheduling problem must account for time window constraints and gas atmosphere transition requirements among jobs, resulting in a complex combinatorial optimization problem that necessitates dual-objective optimization of the total atmosphere transition cost of annealing and the total penalties for time window violations. Most multi-objective optimization algorithms rely on the evolution of a single population, which makes them prone to premature convergence, leading to local optimal solutions and insufficient exploration of the solution space. To address the challenges above effectively, we propose a Bi-population Co-evolutionary Multi-objective Optimization Algorithm (BCMOA). Specifically, the BCMOA initially constructs two independent populations that evolve separately. When the iterative process meets predefined conditions, elite solution sets are extracted from each population for interaction, thereby generating new offspring individuals. Subsequently, these new offspring participate in elite solution selection alongside the parent populations via a non-dominated selection mechanism. The performance of the BCMOA has undergone extensive validation on benchmark datasets. The results show that the BCMOA outperforms its competitive peers in solving the relevant problem, thereby demonstrating significant application potential in industrial scenarios. Full article

Lipophenols, combining phenolic and lipid moieties in a single molecule, are valuable candidates for providing enhanced bioactive properties with therapeutic potential, including anti-inflammatory functions associated with immune-mediated diseases such as intestinal bowel disease (IBD). Thus, palmitoyl–epigallocatechin gallate (PEGCG), a lipophilic derivative of epigallocatechin gallate (EGCG), has been highlighted for its enhanced stability in lipid-rich environments and bioavailability due to improved cellular uptake. However, the contribution of lipophilic esterification to PEGCG’s capacity to inhibit inflammation and the development of harmful autoimmune responses remains underexplored. This work uncovered the differential efficiency of EGCG and its palmitoyl derivative in modulating, in vitro, the interleukin profile generated by intestinal epithelium under inflammatory conditions. Therefore, both could attenuate the immune response by lowering macrophage migration and polarisation towards pro-inflammatory (M1) or anti-inflammatory (M2) phenotypes. While the fatty acid moiety gave PEGCG a functional advantage over EGCG in adjusting the interleukin-based response of intestinal epithelium to inflammation—since both of them decreased, to a similar extent, the expression of pro-inflammatory interleukins, namely IL-6, IL-17, IL-18, IL-23, and TNF-α (which lowered by 11.2%, on average)—the former was significantly more efficient in cushioning the increase in IL-1β and IL-12p70 (by 9.2% and 10.4%, respectively). This immune modulation capacity did not significantly impact the migration and expression of costimulatory molecules featuring M1 (CD86⁺) or M2 (CD206⁺) phenotypes by THP-1-derived macrophages, for which both bioactive compounds exhibited equivalent efficiency. Nonetheless, the analysis of the pro- and anti-inflammatory interleukins secreted by differentiated macrophages allowed the identification of an advantage for PEGCG, which decreased the expression of the pro-inflammatory immune mediators IL-1β and IL-12p70, IL-23, and TNF-α more efficiently. These results suggest that lipophilisation of phenolic compounds presents exciting potential for extending their application as functional molecules by combining the effects of their polar head with their ability to interfere with membranes, conveyed by their lipophilic tail. In addition, the enhanced reactivity would confer a higher capacity to interact with cellular signalling molecules and thus inhibit or attenuate the immune response, which is of special interest for preventing the onset and severity of immune-mediated pathologies such as IBD. Full article

Vehicle suspension significantly influences the safety of cargo transportation. This study presents a 14-degree-of-freedom vehicle–cargo coupling model that explicitly incorporates the frequency-dependent stiffness of air springs. Systematic parametric investigations of air spring orifice resistance, loading mass, and cargo stiffness reveal the following: (a) Compared with leaf spring suspension, air suspension vehicles attenuated the first peak of acceleration power spectral density by over 50%, while slightly amplifying the second peak; (b) When replacing leaf spring suspension with air suspension, the upper-layer cargo exhibited significantly larger vibration reductions (14% vertical, 28% pitch) than the lower-layer cargo under identical cargo parameters. The roll angle should be controlled to prevent the cargo overturning when equipping air suspensions; (c) Under light loading conditions, the vertical vibration response in upper-layer cargo is amplified. This amplification can be effectively suppressed through two complementary approaches, i.e., employing low-stiffness cushion materials and reducing orifice resistance through tunable orifices, which collectively attenuate characteristic peaks in the frequency-domain response and comprehensively mitigate the vertical vibration of cargo. These findings provide guidance for designing transportation schemes for cargo in air suspension vehicles to enhance cargo safety. Full article

Aiming at the lightweight design of a bridge-shed integration structure, this paper presents a three-layered absorbing system in which a part of the sand cushion is replaced by expanded polystyrene (EPS) geofoam and the reinforced concrete (RC) protective slab is arranged above the sand cushion to enhance the composite system’s safety. A three-dimensional Smoothed Particle Hydrodynamics–Finite Element Method (SPH-FEM) coupled numerical model is developed in LS-DYNA (Livermore Software Technology Corporation, Livermore, CA, USA, version R13.1.1), with its validity rigorously verified. The dynamic response of rockfall impacts on the shed slab with composite cushions of various thicknesses is analyzed by varying the thickness of sand and EPS materials. To optimize the cushion design, a specific energy dissipation ratio (SEDR), defined as the energy dissipation rate per unit mass (η/M), is introduced as a key performance metric. Furthermore, the complicated interactional mechanism between the rockfall and the optimum-thickness composite system is rationally interpreted, and the energy dissipation mechanism of the composite cushion is revealed. Using logistic regression, the ultimate stress state of the reactive powder concrete (RPC) slab is methodically analyzed, accounting for the speed and mass of the rockfall. The results are indicative of the fact that the composite cushion not only has less dead weight but also exhibits superior impact resistance compared to the 90 cm sand cushions; the impact resistance performance index SEDR of the three-layered absorbing system reaches 2.5, showing a remarkable 55% enhancement compared to the sand cushion (SEDR = 1.61). Additionally, both the sand cushion and the RC protective slab effectively dissipate most of the impact energy, while the EPS material experiences relatively little internal energy build-up in comparison. This feature overcomes the traditional vulnerability of EPS subjected to impact loads. One of the highlights of the present investigation is the development of an identification model specifically designed to accurately assess the stress state of RPC slabs under various rockfall impact conditions. Full article

Amidst the intensification of global climate change and the increasing impacts of human activities, ecosystem patterns and processes have undergone substantial transformations. The distribution and evolutionary dynamics of mountain ecosystems have become a focal point in ecological research. The Surkhan River Basin is located in the transitional zone between the arid inland regions of Central Asia and the mountain systems, where its unique physical and geographical conditions have shaped distinct patterns of vertical zonation. Utilizing Landsat imagery, this study applies a hierarchical classification approach to derive land cover classifications within the Surkhan River Basin. By integrating the NDVI (normalized difference vegetation index) and DEM (digital elevation model (30 m SRTM)), an “NDVI-DEM-Land Cover” scatterplot is constructed to analyze zonation characteristics from 1980 to 2020. The 2020 results indicate that the elevation boundary between the temperate desert and mountain grassland zones is 1100 m, while the boundary between the alpine cushion vegetation zone and the ice/snow zone is 3770 m. Furthermore, leveraging DEM and LST (land surface temperature) data, a potential energy analysis model is employed to quantify potential energy differentials between adjacent zones, enabling the identification of ecological transition areas. The potential energy analysis further refines the transition zone characteristics, indicating that the transition zone between the temperate desert and mountain grassland zones spans 1078–1139 m with a boundary at 1110 m, while the transition between the alpine cushion vegetation and ice/snow zones spans 3729–3824 m with a boundary at 3768 m. Cross-validation with scatterplot results confirms that the scatterplot analysis effectively delineates stable zonation boundaries with strong spatiotemporal consistency. Moreover, the potential energy analysis offers deeper insights into ecological transition zones, providing refined boundary identification. The integration of these two approaches addresses the dimensional limitations of traditional vertical zonation studies, offering a transferable methodological framework for mountain ecosystem research. Full article

In order to accurately analyze the liquefaction and the reinforcement effect of saturated silty and sandy soils treated by dynamic compaction, a hydro-mechanically coupled explicit analysis method was proposed. The method, in combination with the cap model, was carried out using the Abaqus finite element software. Then, parametric analysis was carried out by means of the development and dissipation of excess pore water pressure, effective soil stress and the relative reinforcement degree. And the effects of the drop energy, tamper radius and soil permeability on the liquefaction zone and soil improvement of saturated soil were examined. The results demonstrated that the liquefaction zone and the effective reinforcement were determined by the drop energy rather than the permeability or tamper radius. A 2.5-times increase in drop energy can increase the maximum liquefaction depth by 1.1 m (4.6 m to 5.7 m) and the effective reinforcement depth (I_r ≥ 0.08) by 0.6 m (1.2 m to 1.8 m). It is recommended that the reinforcement effect should be improved by a lower drop energy with a low drop height and a heavy tamper in actual projects. It should also be noted that a smaller tamper radius was conducive to local soil improvement but also generated higher localized excess pore water pressures. Soil permeability critically controls liquefaction potential and excess pore water pressure dissipation. Low permeability soils experienced significant liquefaction depths and slower consolidation, whereas high permeability gravels (k = 10⁻² m/s) showed minimal liquefaction and great improvements in depth. To diminish the effect of the underground water, the gravel cushions should be used to drain pore water out before dynamic compaction. Full article

In rockfall hazard mitigation, geofoam has been used in the cushion layer to improve the sustainability of the rockfall gallery, such as impact resistance enhancement and dead load reduction. Impact tests were conducted to study the effect of geofoam type, thickness, and impact energy on the impact responses of the sand cushion layer. The test results showed that placing geofoam in the sand cushion can reduce the peak impact force of the rockfall and the peak acceleration of the gallery slab by up to 80%. While the peak impact stress at the cushion layer bottom can also be reduced by geofoam under low impact energy, thicker geofoam layers (e.g., 4 and 6 cm) increased peak impact stress when the rockfall had high impact energy. Placing geofoam at the bottom of the cushion to replace one third of the sand cushion thickness can enhance the impact resistance of the cushion layer. Under low impact energy, expandable polyethylene (EPE) foam resulted in lower impact force on the rockfall, reduced impact stress within the sand cushion, and diminished vibration of the gallery slab compared with polystyrene (EPS) foam with a constant thickness. However, EPS foam is suitable for use in sand cushions of rockfall galleries subjected to high-energy rock impacts. Moreover, EPE foam exhibits superior resilience, resulting in less damage compared to EPS foam. Full article

Standalone tsunami defense structures have demonstrated limitations in mitigating wave energy during the 2011 Japan tsunami. In order to mitigate future tsunamis in Japan, multi-layered protective mechanisms have been suggested or implemented after the incident. These include heightening the destroyed or existing embankment with concrete or stones, protecting embankments with concrete blocks, compacting the landward soil, elevating the ground following the coastal embankment, and incorporating green belts. Despite extensive research on the mitigation effects of such multiple countermeasures, the optimal structural configuration remains uncertain. In this study, we evaluated the performance of a multiple mitigation system consisting of a landward forest (F) on an elevated mound (M) following a seaward embankment (E) under a range of supercritical flow conditions using a flume experiment. Several mound heights and lengths were selected to determine the optimum mound for installing the forest. The combination of E and F of 12 rows of trees on M with a minimum height of 1.8 cm (Case EMF_R12) created the greatest water cushion depth between E and M. When M was positioned without F, the water cushion between E and M was created by raising the height of the mound rather than its length. Conversely, a mound with a minimum height and length with a forest was found to be effective in creating the largest water cushion and maximum reduction of the flow energy. The highest energy reduction was between 45 and 70% in this experiment. These findings provide useful insights for developing multiple tsunami mitigation strategies that combine artificial and natural approaches. Full article

Background: Soft liners offer a cushioning effect that aids in the healing of inflamed mucosa and allocates the relevant load in the support area of prostheses, enhancing their fit and stability. This study looks at how strontium-infused phosphate bioactive glass affects a heat-cured acrylic-based soft liner, focusing on the surface hardness and the surface roughness of the material. Methods: One hundred soft liner specimens were produced, with fifty specimens being designated for surface hardness testing and fifty specimens for surface roughness testing. PBG*Sr was incorporated into the soft liner at the concentrations of 1 wt.%, 3 wt.%, 5 wt.%, and 7 wt.%. Surface hardness and surface roughness were evaluated with a digital durometer for Shore A hardness and a profilometer, respectively. Fourier transform infrared spectroscopy analysis and field emission scanning electron microscopy were employed. Results: The Shapiro–Wilk test demonstrated that the data adhered to a normal distribution, as the p-values were not statistically significant. Subsequently, for statistical analyses following the one-way ANOVA, Dunnett’s T3 post hoc test was employed for surface hardness, while Tukey’s post hoc test was used for surface roughness. The lowest hardness value was documented in the 7 wt.% subgroup (29.040 ± 0.070), followed by the 5 wt.% subgroup (30.97 ± 0.231), and the control (40.880 ± 0.473) had the highest hardness mean value. The 7 wt.% subgroup displayed the lowest value of Ra recorded, 0.489 ± 0.077 μm, while the control subgroup showed the highest, 1.994 ± 0.168 μm. FTIR analysis suggested that the domination of physical interactions according to the analyses with the FESEM led to improved surface morphology for the 7 wt.% PBG*Sr specimens. Conclusions: The 7 wt.% PBG*Sr specimens exhibited the lowest surface hardness, suitable for soft lining material, and improved the surface morphology of acrylic soft liners compared with the control and other concentrations. Full article

Running socks play an important role in alleviating foot impact and preventing foot injuries. Despite the variety of commercial options, their cushioning effectiveness is not well understood. This study examines three different types of running socks made of bio-based and synthetic textiles. Material testing includes compression, tensile, and shock absorption, while wear tests assess plantar loading in 10 adult recreational runners on a treadmill. Results show that specialized running socks offer superior shock absorption compared to regular running socks, largely due to fabric thickness and weight. Socks made of high-performance bio-composite fibers significantly reduced maximum peak pressure and impulse in the great toe (p < 0.05) and first metatarsal head (p < 0.05) during running. Additionally, ground contact time in the forefoot (p < 0.05) area was significantly lower with specialized running socks. Compared to regular running socks, five-toed running socks can reduce the pressure load on the forefoot area. These findings can guide the design of specialized sockwear for better foot protection and improved sports performance. Full article

Articular cartilage (AC) plays an important role in the biomechanics of synovial joints. Its task is to enable smooth movement and transfer of mechanical loads with minimised friction. AC is characterised by unique mechanical properties resulting from its complex structure, in which the dominant components are type II collagen, proteoglycans and water. Healthy articular cartilage shows elasticity in compression, viscoelastic properties, and the ability to relax stresses under the influence of cyclic loads. In response to different loading modes, it shows anisotropic and non-uniform behaviour, which translates into its cushioning and protective function for the subchondral bone. Significant changes occur in the structure and mechanical properties of cartilage with age as a result of mechanical overload or degenerative diseases, such as osteoarthritis. This results in a deterioration of the cushioning and mechanical function, which leads to progressive degradation of joint tissues. Understanding the mechanical properties of AC is crucial for developing effective diagnostic methods. Analysis of changes in mechanical properties contributes to the early detection of pathological changes. The aim of this paper is to review the current state of knowledge regarding the structure and biomechanical properties of articular cartilage, and to analyse conventional and alternative diagnostic methods in the context of their suitability for assessing the state of AC, particularly in the early stages of degenerative processes. Full article

The COVID-19 pandemic intensified existing structural challenges in Africa, including poverty, weak healthcare systems, and fragile agricultural supply chains. Consequently, examining its effects remains a critical area of study. This research investigates the effect of food prices on the prevalence of malnutrition in the context of the COVID-19 pandemic in sub-Saharan Africa. The findings indicate a significant long-term relationship between the number of COVID-19 cases, food prices, and the prevalence of undernourishment. Specifically, increases in food prices are associated with a rise in undernourishment rates over the long term. These results are corroborated by estimations using Fully Modified Ordinary Least Squares (FMOLS). To mitigate malnutrition in the face of potential future health shocks, governments could create and operationalize food price stabilization funds to cushion against sharp increases in food prices. These funds can be used to subsidize key staples during periods of price volatility, ensuring affordability for vulnerable populations. Full article

Mycelium-based biocomposites represent a novel class of environmentally friendly materials. This study investigated the potential of using Salix psammophila and peanut straw as substrates for cultivating Pleurotus ostreatus and Ganoderma lucidum, respectively, to fabricate mycelium-based cushioning materials. The results demonstrated that the Pleurotus ostreatus-based cushion material using Salix psammophila (POSM) outperformed the Ganoderma lucidum-based cushion material using peanut straw (GLPM) in terms of overall performance. Both materials presented optimal comprehensive properties when the cultivation period reached 30 days. Increasing the substrate length enhanced most of the material properties. The resulting density ranged from 0.13 to 0.16 g/cm³, which was higher than that of polystyrene foam. The contact angles of both materials exceeded 120°, whereas their elastic springback rates reached 50.2% and 43.2%, and their thermal conductivities were 0.049 W/m·K and 0.051 W/m·K, respectively. Additionally, thermogravimetric analysis revealed that both materials exhibited similar thermal degradation behavior and relatively high thermal stability. These findings align with those of previous studies on mycelium composites and indicate that the physical and mechanical properties of the materials are largely comparable to those of expanded polystyrene (EPS). In conclusion, the developed mycelium-based cushioning materials promote the efficient utilization of agricultural residues and hold promise as a sustainable alternative to EPS, offering broad application prospects in the transportation and packaging sectors. Full article