All-cellulose composites (ACC) are reinforced and impregnated entirely with cellulose. In this study, ramie (Boehmeria nivea) was used as reinforcement materials because of their excellent mechanical properties and then combined with luffa (Luffa cylindrica) cellulose as the matrix to fabricate ACC with the conventional impregnation method (CIM). The NaOH/urea solution was selected to dissolve luffa cellulose. Epichlorohydrin (ECH) was added to the cellulose solution as a crosslinker for hydrogel formation. Scanning electron microscope (SEM) was conducted to evaluate the interaction between ramie fibers and luffa matrices. The mechanical properties, density, and wettability were evaluated by varying the fiber mass fraction. The results showed that ACC from ramie-luffa had a tensile strength of 35.13 MPa at a high fiber fraction, a density under 1.3 g cm-3, and an average contact angle of up to 92.1 degrees. Soil-burial testing was conducted to approach the degradability of the ACC. The results demonstrated that the degradation of ACC reached 64.41 % after 28 days of burial in the soil. These findings suggest that ACC from ramie and luffa holds significant potential as a sustainable and environmentally friendly composite.

Seismic risk assessment is pivotal for ensuring the reliability of prefabricated subway stations, where selecting optimal intensity measures (IMs) critically enhances probabilistic seismic demand models and fragility analysis. While peak ground acceleration (PGA) is widely adopted for above-ground structures, its suitability for underground systems remains debated due to distinct dynamic behaviors. This study identifies the most appropriate IMs for soft soil-embedded prefabricated subway stations at varying depths through nonlinear finite element modeling and develops corresponding fragility curves. A soil-structure interaction model was developed to systematically compare seismic responses of shallow-buried, medium-buried, and deep-buried stations under diverse intensities. Incremental dynamic analysis was employed to construct probabilistic demand models, while candidate IMs (PGA, PGV, and vrms) were evaluated using a multi-criteria framework assessing correlation, efficiency, practicality, and proficiency. The results demonstrate that burial depth significantly influences IM selection: PGA performs optimally for shallow depths, peak ground velocity (PGV) excels for medium depths, and root mean square velocity (vrms) proves most effective for deep-buried stations. Based on these optimized IMs, seismic fragility curves were generated, quantifying damage probability characteristics across burial conditions. The study provides a transferable IM selection methodology, advancing seismic risk assessment accuracy for prefabricated underground infrastructure. Through a systematic investigation of the correlation between IM applicability and burial depth, coupled with the development of fragility relationships, this study establishes a robust technical framework for enhancing the seismic performance of subway stations, and provides valuable insights for seismic risk assessment methodologies in underground infrastructure systems.

This paper uses shake table tests to study tunnel landslide failures in earthquake zones under four conditions: (GK1) the tunnel intersects the sliding mass, (GK2) the tunnel is perpendicular to the sliding surface, (GK3) the tunnel is positioned below the sliding surface, and (GK4) the tunnel is situated above the bedrock. The dynamic responses under the four conditions are analyzed using time-domain strain analysis methods. Additionally, from an energy perspective, the amplified Arias intensity (MIa) is employed to characterize the cumulative deformation damage of the tunnel lining. The results indicate that under four working conditions, the upper landslide region of the tunnel landslide system exhibits a settlement-compression-shear type of sliding failure. However, in conditions GK1 and GK2, where the lining structure is present, the tunnel lining provides additional support to the landslide, resulting in less severe damage to the slope compared to conditions GK3 and GK4. However, under conditions GK1 and GK2, the left sidewall of the tunnel lining experiences more severe damage due to landslide pressure. The maximum soil pressure and bending moment on the left sidewalls in GK3 and GK4 are only 40-60% of those observed in GK1 and GK2. In addition, based on the trend of MIa, the cumulative deformation evolution of the tunnel lining can be categorized into three stages: the initial stage (0.1-0.2 g), the progressive deformation stage (0.2-0.4 g), and the failure deformation stage (0.4-0.6 g). Further research confirms that under seismic action, the slope experiences a significant progressive catastrophic evolution. This process is characterized by typical seismic cumulative damage effects, with sustained seismic loading causing deformation and damage to gradually expand from localized areas to the entire slope. This continuous fatigue effect progressively weakens the stability of the lining structure, ultimately leading to its failure. Therefore, the deformation and damage of the slope under seismic loading pose a serious threat to the safety of tunnel linings, highlighting the need for close attention to their long-term stability. The research results provide a scientific basis for reinforcing tunnel linings in earthquake-prone mountainous areas.

The recurrent crystallization and subsequent volumetric expansion of soluble salts pose significant risks to earthen sites, particularly those with archaeological remains on their surfaces. Therefore, timing interventions based on salt content is crucial. This study focuses on the effects of soluble salt content on the earthen site within the burial pits of the Qin Mausoleum, with a particular emphasis on defining safe salinity levels. A mixture of Na2SO4/NaCl salts in a 1:1 mass ratio was added to remodelled soil cakes, which were then aged in a climate chamber for several months. The area of salt expansion on the soil cakes' surfaces was measured using a deep-focus microscope to assess damage. The results indicate a sudden increase in salt expansion when salinity exceeded 0.1%. Additionally, re-evaluations of these soil cakes years later allowed for the exploration of mechanisms and the feasibility of assessing soil surface expansion and friability at different stages of the earthen site's lifecycle, including excavation and display. These findings provide preliminary scientific bases and novel methodologies for the further preventive conservation of heritage earthen sites.

The depth of seed burial and impact damage are critical indicators of sowing quality in wheat accelerated seeding technology. To investigate the factors influencing seed burial depth and impact damage, a simulation model of wheat seed impact and soil penetration was developed using EDEM (2018) software, and the motion of wheat seed impact into soil was simulated and analyzed to identify the main influencing factors of wheat seed impact into soil. Seeding velocity, wheat seed equivalent diameter, and soil surface energy were selected as experimental factors, while burial depth and maximum impact force were chosen as response indicators. Both single-factor tests and three-factor, three-level orthogonal tests were conducted. Single-factor simulations showed that burial depth increased with seeding velocity and seed diameter, but decreased with soil surface energy. In contrast, maximum impact force increased with velocity and diameter, peaking at low soil surface energy before declining beyond a threshold. The orthogonal test results indicated that a maximum burial depth of 26.37 mm and a maximum impact force of 0.0704 N were achieved when the wheat seed diameter was 4 mm, the seeding velocity was 65 m/s, and the soil surface energy was 0.5 J/m2. Bench tests were conducted to validate the simulation results further. The results of the bench tests were consistent with the simulation results, with relative deviations of less than 5%, indicating the reliability of the simulation outcomes. This experimental study has provided data and a theoretical basis for the selection of technical parameters and the design and application of accelerated sowing technology for wheat.

The prevalent presence of microplastics in marine environments poses major ecological risks requiring innovative approaches to their management and reduction. This study addresses a knowledge gap in biodegradable microplastic alternatives by looking at the biodegradability and properties of reclaimed microplastic polypropylene (PP) blended with polylactic acid (PLA). The study lies in the systematic exploration of various PP/PLA formulations, evaluating their potential for enhanced biodegradability without significantly compromising mechanical performance. Microplastic PP and PLA blends were prepared in various ratios using the melt blending method. The blend was characterized using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) to confirm the presence and morphology of the components. The mechanical properties were evaluated using tensile strength tests. A blend of 90% PP and 10% PLA was found to retain the highest tensile strength even after immersion in seawater. The thermal stability and degradation behavior were analyzed using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). This shows that increasing PLA content affects the thermal properties of the blends. Seawater immersion and soil burial tests were used to assess the biodegradability of the blends. The results showed that the blends' biodegradation was confirmed by increases in conductivity and salinity in the seawater and weight loss in the soil burial. The major findings show that blending PP and PLA improves biodegradability while maintaining adequate mechanical properties. Tests including immersion in saltwater and soil burial were used to assess the biodegradability of the blends. The results showed that the blends' biodegradation was confirmed by increases in conductivity and salinity in the seawater and weight loss in the soil burial. The major findings show that blending PP and PLA improves biodegradability while maintaining adequate mechanical properties. Finally, this study presents a new approach to reducing microplastic pollution through the blend of reclaimed PP with biodegradable PLA, resulting in a sustainable material with improved environmental performance. Future studies should look into new formulations, biodegradable polymers, and long-term degradation tests under a variety of environmental circumstances.

Cellulose crystallinity can be altered by various treatment methods, including mechanical or chemical treatments, which can affect the properties of thermoplastic composites. In this study, the crystallinity of cellulose was manipulated using mechanical ball milling. The primary objective was to assess the impact of altering the cellulose crystallinity on the overall performance of high-density polyethylene (HDPE)-based composites. The mechanical and structural properties of the composites were assessed using tensile and impact tests, attenuated total reflectance infrared ( ATR-IR ) spectroscopy, scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The degradation properties of the HDPE composites were evaluated using a soil-burial degradation test. The impact of cellulose crystallinity on the mechanical properties of HDPE composites showed a marginal enhancement of 5% in tensile strength with the incorporation of 2% low-crystallinity cellulose (LCC). The highest impact strength of the HDPE composites was attained by the incorporation of 6% LCC. ATR-IR analysis showed that the peak intensity of the HDPE-LCC composite decreased, whereas the HDPE composite with high-crystallinity cellulose (HCC) did not exhibit changes in peak intensity compared to the HDPE spectrum. SEM examination showed that LCC possessed superior dispersion in the HDPE matrix compared to that of HCC. Thermal degradation decreased by up to 32% with the addition of HCC and LCC. A soil burial degradation study showed that the mechanical properties of the HDPE-LCC composite deteriorated more than those of the HDPE-HCC composite after 24 months. This study concluded that altering the crystallinity of cellulose can lead to composites with tailored properties.

As renewable energy demand increases, protecting subsea cables from ship anchor damage has become essential. This research comprises numerical simulations of the anchor penetration process in Baltic Sea sand (for an AC-14, a Hall and a Spek anchor). We apply a coupled Eulerian-Lagrangian (CEL) framework and a hypoplasticity constitutive model to analyze the influence of different anchor characteristics on penetration depth and seabed stress distributions. We conducted investigations under high velocities (v >= 1 m/s) with focus on inertial effects only. Furthermore, this study introduces stress circles to visualize a simplified anchor- induced spatial stress distribution in the seabed. Findings show that heavier anchors and slower drag velocities generally result in deeper anchor penetrations. Fluke geometry significantly affects penetration depth, with pointed designs penetrating more deeply. The observed trends align with previous results from centrifuge tests and numerical modeling of ship anchors. This research improves understanding of soil-structure interaction in maritime environments, offering insights for the protection of subsea installations in the Baltic Sea and similar regions.

This study investigates the incorporation of thermoplastic starch (TPS) into polybutylene adipate terephthalate (PBAT) to create biodegradable plastic wraps for pathological waste burial in soil. TPS is added to PBAT to enhance biodegradability, as PBAT alone degrades slowly. The research examines the mechanical properties, biodegradation, morphology, and swelling behaviour of the blends. Key tests include xenon arc light exposure for accelerated aging, a formalin swelling test for permeability, and soil degradation analysis for weight loss. Results show that adding TPS significantly reduces tensile strength (65.53%) and elongation at break (93.35%), but the material still effectively serves its purpose as a wrapping for pathological waste. Morphological analysis reveals phase separation, and UV exposure further decreases tensile strength by 27.6%. The highest TPS composition (30TPS/70PBAT) shows the fastest mechanical degradation, indicating accelerated biodegradation. Despite minimal formalin absorption (16% within 1 day), the blends prevent formalin leaching, making them suitable for pathological waste containment.

The interest in natural fibres in non - textile applications has increased as a result of the search for new renewable materials. Especially attractive for environmental safety demands are biodegradable and renewable fibres such as lignocellulose fibres and biopolymers such as PLA. The analysis of their biodegradation is often taken as a standard measure for environmentally friendly textile materials. Therefore, the aim of this paper is to investigate the biodegradation properties of Jute and PLA fibres by soil burial test. The fibres were exposed to the farmland soil for 11 days. The efficiency of the biodegradability was determined by comparison of mass loss, mechanical properties (finesses and tenacity) and morphological analysis by SEM microscope. With the purpose of a better understanding of biodegradation, the number of total fungi and bacteria in the soil is also determined.