Maximizing agricultural tractor energy efficiency is crucial for sustainable farming. Tractors are one of the most popular machines in use in agriculture, and much of their use is dedicated to drawbar operations. Under these conditions, only up to 70 % of engine power is transferred to the soil, and this may even drop to 50 % on soils with poor mechanical properties. Recently, tyres which meet very high flexion standards have hit the market and to date, no study has performed a thorough full-vehicle traction analysis of vehicles equipped with such standards. This paper investigated the influence of tyres on vehicle performance and efficiency. Moreover, a cost analysis of the new tyre technology was carried out to assess the duration of use necessary for farmers to recoup the financial investment this new tyre technology requires. The analysis comprised steady-state drawbar tests on two soil types using a tractor rated at 230 kW and equipped with wheel force transducers. Key performance indicators were calculated from the collected data. Results showed superior traction on softer soil, where the mean vehicle traction ratio was 6.4 % higher than on firmer soil, highlighting tyre set performance differences. However, traction efficiency was 17.5 % greater on firmer soil. Very high flexion tyres resulted in improved indicators in both soils and despite the greater cost of tyres using the new standard, farmers may obtain economic benefits even within a year if such tyres are mostly used in field operations and on soft soils.

The soil moisture content (SMC) of moist clay directly affects the traction performance of off-road tire. This study set up a high-fidelity interaction model between off-road tire and moist clay with various moisture content, developed by coupling the finite element method (FEM) and smoothed particle hydrodynamics (SPH) algorithm. The interaction behavior between pneumatic tire and moist clay is studied. Firstly, a finite element model of tire which can characterize the complex structure and nonlinear mechanical properties is established. The Drucker-Prager (D-P) constitutive model parameters of clay with various moisture levels are calibrated by soil mechanical test. The moist clay with various moisture content is modeled through the SPH algorithm. The hybrid FEM-SPH interaction model is used to define the tire-moist clay interaction. Moreover, a traction performance test device suitable for tire-moist clay is developed to verify the accuracy of the interaction model. The influence of soil moisture content and tire operating conditions include vertical load and inflation pressure on the longitudinal traction coefficient, rolling resistance coefficient and instantaneous sinkage of tire center are quantitatively analyzed. The purpose of this study is to provide accurate tire force information under moist clay for unmanned ground vehicle (UGV), which can improve the problem of wheel instantaneous sinkage of tire center and slip under moist clay, and effectively reduce the yaw phenomenon in the path tracking process.

Accurate structural health monitoring (SHM) is crucial for ensuring safety and preventing catastrophic failures. However, conventional parameter identification methods often assume a fixed-base foundation, neglecting the significant influence of soil-structure interaction (SSI) on the dynamic response, leading to inaccurate damage assessments, especially under seismic loading. Therefore, we introduce a novel approach that explicitly incorporates SSI effects into parameter identification for frame structures, utilizing an optimized variational mode decomposition (VMD) technique. The core innovation is the application of the Subtraction Average-Based Optimizer (SABO) algorithm, coupled with permutation entropy as the fitness function, to optimize the critical VMD parameters. This SABO-VMD method was rigorously validated through a shaking table test on a 12-story frame structure on soft soil. Comparative analysis with EMD and conventional VMD demonstrated that SABO-VMD provides a superior time-frequency representation of the structural response, capturing non-stationary characteristics more effectively. A novel energy entropy index, derived from the SABO-VMD output with SSI, was developed for quantitative damage assessment. It revealed 8.1% lower degree of structural damage compared to the fixed-base assumption. The proposed SABO-VMD-based approach, by explicitly accounting for SSI, offers a substantial advancement in SHM of frame structures, leading to more reliable safety evaluations and improved seismic resilience.

Soil liquefaction is a major contributor to earthquake damage. Evaluating the potential for liquefaction by conventional experimental or empirical methods is both time-intensive and laborious. Utilizing a machine learning model capable of precisely forecasting liquefaction potential might diminish the time, effort, and expenses involved. This research introduces an innovative predictive model created in three phases. Initially, correlation analysis determines essential elements affecting liquefaction. Secondly, predictions are produced using Convolutional Neural Networks (CNN) and Deep Belief Networks (DBN), verified by K-fold cross-validation to guarantee resilience. Third, Ant Colony Optimization (ACO) improves outcomes by increasing convergence efficiency and circumventing local minima. The suggested EC + ACO model substantially surpassed leading approaches, such as SVM-GWO, RF-GWO, and Ensemble Classifier-GA, attaining a very low False Negative Rate (FNR) of 2.00 % when trained on 90 % of the data. A thorough performance evaluation shown that the model achieved a cost value of 1.133 % by the 40th iteration, exceeding the performance of other models such SVMGWO (1.412 %), RF-GWO (1.305 %), and Biogeography Optimized-Based ANFIS (1.7439 %). The model exhibited significant improvements in convergence behavior, with a steady decline in cost values, especially between the 20th and 50th iterations. Additional validation using empirical data from the Tohoku-oki, Great East Japan earthquake substantiated the EC + ACO model's enhanced accuracy and dependability in mirroring observed results. These findings underscore the model's resilience and efficacy, providing a dependable method for forecasting soil liquefaction and mitigating its seismic effects.

Expansive soil, a commonly distributed clay, is unsuitable for direct engineering applications. This study proposes a method to produce foam lightweight soil from expansive soil, effectively mitigating its expansive properties. The physical and mechanical properties of expansive soil-based lightweight soil (E-LS) were systematically investigated under varying water-solid ratios, wet densities, and expansive soil contents, using tests for flow value test, drying shrinkage test, pH test, and compressive strength test. An orthogonal experiment was conducted to quantify the influence of these factors on unconfined compressive strength (q(u)), leading to the development of a strength determination method. The results show that the preparation of E-LS modifies the expansive soil structure, completely eliminating its expansiveness. Compressive strength of E-LS increases with both wet density and curing age. For expansive soil contents ranging from 30% to 60%, the unconfined compressive strength at 28 days (q(u-28 d)) varied from 0.21 MPa to 1.58 MPa. Specifically, for E-LS with 50% expansive soil content, a water-to-solid ratio of 0.8, and a wet density of 900 kg/m(3), the q(u-28 d) reached 0.92 MPa, meeting the requirements for embankment construction. The factors affecting compressive strength are ranked as expansive soil content wet density water-solid ratio, and a predictive model for E-LS strength was developed. E-LS exhibits the capability to fulfill diverse embankment filling requirements in engineering applications, while demonstrating distinct advantages including expansive property mitigation, compaction-free implementation, and construction efficiency, thereby presenting significant potential for practical engineering deployment.

The suction foundation (SF) has significant resistance reduction effect due to the seepage effect under the suction-assisted penetration. Seepage is an important factor in resistance reduction. In this paper, the model experiments and numerical simulation method were employed to analyze the resistance of suction-assisted penetration in sand. By analyzing the mechanism of resistance reduction, a suction foundation for enhancing seepage (SFES) has been proposed. The SFES was installed the degradable material inside the SF. The size of the degradable materials is smaller than the inner diameter of the foundation. During suction-assisted penetration, water suddenly contracts inside the foundation, resulting in a decrease in excess pore pressure on the inner side of the foundation and ultimately reducing installation resistance. The coefficient of evaluating the change of penetration resistance under seepage action was put forward. The results had shown that the pore water pressure of the sandy soil near foundation wall was reduced by the sudden contraction during the suction-assisted penetration, which was more conducive to resistance reduction. Under the same penetration depth, the inner resistance of the SFES change coefficient was 8.4 %-25.9 % smaller than that of SF. When the relative penetration depth h/D >= 0.25, the area of piping (4 >= 1) region within SFES was smaller than that of SF. As h/D = 0.9, the area of piping (4 >= 1) region within SFES producing piping was 27.9 % less than SF. The SFES had more advantages in the suction-assisted penetration.

Thorium extraction techniques, such as solvent extraction from monazite and electrosorption techniques from water leach purification (WLP) of radioactive waste residues, are important for thorium recovery, particularly in Malaysia. Despite their importance, previous studies have largely overlooked critical issues like radioactive hazards, human health risks, and environmental impacts associated with advanced thorium extraction methods. This study addresses these gaps by quantifying the environmental impact associated with solvent extraction and electrosorption techniques using a life cycle assessment (LCA) framework to compare environmental indicators for thorium recovery from monazite ore and WLP residues. The LCA was conducted from cradle to gate, incorporating inventory data from the Ecoinvent database 3 and SimaPro software version 9, with inputs of raw material extraction, transportation, energy consumption, and chemical uses. Emissions into air, water, and soil were quantified across all processing phases. The LCA midpoint findings reveal that thorium disulfate in monazite processing is the key contributor to global warming, producing 45 kg CO2-eq, whereas transportation and electricity consumption also considerably affect emissions, contributing 25.07 kg CO2-eq and 26.17 kg CO2-eq, respectively. Comparative analysis of midpoint indicators showed that solvent extraction had a more significant environmental impact than electrosorption in the context of human carcinogenic toxicity, freshwater ecotoxicity, and marine ecotoxicity. The damaged assessment highlighted endpoint indicators that monazite processing had a higher impact than WLP on human health (0.0364-0.0016 DALY), ecosystems (0.0016-0.0005 species & sdot;yr), and resources (0.0012-0.0005 USD, 2013), primarily due to the use of chemicals and emissions. Our study shows that electrosorption from WLP demonstrates superior environmental sustainability compared with solvent extraction from monazite, positioning it a more viable and efficient approach for radioactive waste treatment.

To investigate the unloading mechanical properties of deeply buried silty soil in dam foundation cover layers, a series of consolidated drained triaxial compression tests along multi-stage loading-unloading path were performed on both undisturbed samples (including horizontally and vertically oriented samples) and remolded samples. The test results demonstrate that: (1) the vertically oriented soil samples exhibit strain softening under low confining pressures (100, 200, and 400 kPa), transitioning to strain hardening at high confining pressures (800 and 1600 kPa). In contrast, the horizontally oriented specimens consistently exhibit strain softening across all confining pressures, whereas the remolded samples display strain hardening under all confining conditions; (2) the strength of vertically oriented soil specimens is significantly higher than that of horizontally oriented specimens, ranging from 1.18 to 1.43 times greater. Remolded samples, however, remolded samples are slightly weaker than horizontally oriented specimens under low confining pressures (100, 200, and 400 kPa), while at high confining pressures (800 and 1600 kPa), their strength approaches that of horizontally oriented specimens; (3) the deeply buried silty soil also exhibits pronounced unloading-induced volume contraction characteristics, which increase with the initial axial strain at the beginning of unloading and diminish as confining pressure increases; (4) the unloading modulus is obviously higher than the initial loading modulus, with the ratio of the unloading modulus to the initial loading modulus ranging from 1.4 to 3.6. This ratio increases with increasing confining pressure but decreases with increasing axial strain at the onset of unloading.

Cyst nematodes, some of the most important plantparasitic nematodes globally, cause major damage to Chinese cabbage and soybean plants in Korea. Cysts are commonly used for cyst nematode bioassays because many eggs are included inside cyst. Traditionally, cysts are extracted from the soil using the paper strip method or the centrifugal flotation method (CFM) combined with sieving. The specific gravity of sugar solution (SGSS) is often used in the CFM; however, the efficiency of cyst extraction and egg hatching in the CFM has not been studied. In this study, we assessed the effects of SGSS in a specific gravity range of 1.15 to 1.30 in the CFM on the cyst extraction and egg hatching of clover cyst nematode (Heterodera trifolii) and sugar beet cyst nematode (H. schachtii). High SGSS in the CFM within the range of 1.15 to 1.30 was positively correlated with the extraction of more cysts. Egg-hatching rates were not different between SGSSs, indicating that SGSS did not directly affect egg-hatching rates. These results showed that the cysts of cyst nematodes can be efficiently extracted with high SGSS in the CFM.

Paddy soils undergo wet-dry cycles that greatly influence the behaviour and availability of nutrients, but also of potentially toxic elements (PTEs). This study assessed the quality of paddy soils (actively cultivated and abandoned) and rice (white, brown, and wild) produced in the Baixo Vouga Lagunar (BVL) region, central-north Portugal. Surface soils were analysed for physicochemical parameters and chemical compositions, alongside sequential selective chemical extraction to evaluate metal(loid) availability. Chemical analyses were also performed on interstitial- and irrigation waters, and rice grains. The BVL soils are very strongly to moderately acidic (pH = 4.4-5.8), with organic matter contents reaching up to 34%, and exhibit a wide range of electrical conductivity values. Abandoned rice fields generally show higher values of these parameters and evidence of saline water intrusion. Several sites showed As, Cu, Pb, and U concentrations exceeding Portuguese thresholds for agricultural soils. While Cu levels were similar in both cultivated and abandoned fields, the latter had higher contents of As, Pb, and U. A geogenic origin is envisaged for these metal(loid)s, though anthropogenic contributions cannot be excluded. Sequential selective chemical extraction showed that Pb and U are strongly associated with available fractions, whereas amorphous Fe-oxyhydroxides primarily support As and Cu. Nevertheless, porewaters and irrigation waters showed low concentrations of these PTEs, suggesting minimal mobilisation to water. Furthermore, translocation to rice grains was low, with concentrations well below European Commission limits, indicating that elevated PTEs in soils do not necessarily lead to toxic levels in rice, providing reassurance regarding food safety.