The cracking during the drying process of thickened tailings stack is a critical issue impacting its stability. This study establishes a comprehensive analytical framework that encompasses both mechanism cognition and technical methodologies by systematically integrating multidimensional research findings. Research indicates that cracking results from the coupling effects of environmental parameters and process conditions. The environmental chamber, with its precise control over external conditions, has emerged as essential experimental equipment for simulating actual working environments. From a mechanical perspective, water evaporation induces volume shrinkage, leading to microcrack formation when local tensile stress surpasses the matrix's tensile strength, ultimately resulting in a network of interconnected cracks. This process is governed by the dual parameters of matric suction and tensile strength. In terms of theoretical modeling, the fracture mechanics model analyzes crack propagation laws from an energy dissipation standpoint, while the stress path analysis model emphasizes the consolidation shrinkage coupling effect. The tensile damage model is particularly advantageous for engineering practice due to its parameter measurability. In numerical simulation technology, the finite element method is constrained by the predetermined crack path, whereas the discrete element method can dynamically reconstruct the crack evolution process but encounters the technical challenge of large-scale multi-field coupling calculations. Research suggests that future efforts should focus on optimizing theoretical prediction models that account for the characteristics and cracking behavior of tailings materials. Additionally, it is essential to develop a comprehensive equipment system that integrates real-time monitoring, intelligent regulation, and data analysis. This paper innovatively proposes the establishment of a multi-scale collaborative research paradigm that integrates indoor testing, numerical simulation, and on-site monitoring. By employing data fusion technology, it aims to enhance the accuracy of crack predictions and provide both theoretical support and technical guarantees for the safety prevention and control of thickened tailings stacks throughout their entire life cycle.

Ice records provide a qualitative rather than a quantitative indication of the trend of climate change. Using the bulk aerodynamic method and degree day model, this study quantified ice mass loss attributable to sublimation/evaporation (S/E) and meltwater on the basis of integrated observations (1960-2006) of glacier-related and atmospheric variables in the northeastern Tibetan Plateau. During 1961-2005, the average annual mass loss in the ice core was 95.33 +/- 20.56 mm w.e. (minimum: 78.97 mm w.e. in 1967, maximum: 146.67 mm w.e. in 2001), while the average ratio of the revised annual ice accumulation was 21.2 +/- 7.7% (minimum: 11.0% in 1992, maximum 44.8% in 2000). A quantitative formula expressing the relationship between S/E and air temperature at the monthly scale was established, which could be extended to estimation of S/E changes of other glaciers in other regions. The elevation effect on alpine precipitation determined using revised ice accumulation and instrumental data was found remarkable. This work established a method for quantitative assessment of the temporal variation in ice core mass loss, and advanced the reconstruction of long-term precipitation at high elevations. Importantly, the formula established for reconstruction of S/E from temperature time series data could be used in other regions.

In food packaging industry, plastic was the most commonly used material for packaging, which caused serious pollution to the marine and soil environment. The researches on biodegradable films development from biodegradable polymers was arise, which was expected to ensure the quality and safety of food as much as possible. Biodegradable materials for films included polysaccharides and proteins of different biological sources, and synthetic materials. This review discussed the molecular characteristics and film-forming properties of natural polymer materials of polysaccharides from halobios, plant and microorganism, protein from animal, plant, milk. In addition, the effects of polymerization degree, crystallinity, and film-forming process of synthetic materials (polycaprolactone, polyvinyl alcohol, polylactic acid) on film performance was studied. In order to improve the practicality of biodegradable films in food packaging, many methods were explored to enhance the physical performance of the films. The enhancement strategies including: introduction of nanoparticles, chemical modification, and blending with other polymers, which can effectively enhance the mechanical properties and water vapor barrier performance of biodegradable films. Furthermore, it will provide a reference for future research interest that to development biodegradable food packaging films with high mechanical and barrier properties.

In this study, a novel 2D method for measuring soil surface suction, leveraging infrared thermal imaging technology is presented. The main principle of this method is the establishment of a correlation between soil surface water content and a normalized interfacial temperature difference. Subsequently, we link unsaturated soil surface suction to the normalized interfacial temperature difference through the soil-water characteristic curve. To validate the proposed method, an in-situ calibration test was conducted to ascertain the requisite parameters. Then, the method was tested under varying meteorological conditions at two distinct in-situ sites using the same test protocol as the calibration phase. The results demonstrate a strong agreement compared to measured values, affirming the feasibility and robustness of the proposed approach. This method offers several noteworthy advantages, including rapidity, non-contact operation, non-destructiveness, and robustness to environmental fluctuations. It holds promise for advancing investigation of the spatial and temporal evolution of hydro-mechanical properties of in-situ soil under the influence of climate change.

The moisture accumulation and freezing damage of coarse-grained fill (CGF) in high-speed railway (HSR) subgrades have been widely concerned. Based on the newly developed water-vapor-heat-mechanical coupling test apparatus, a series of soil column tests were carried out to investigate the frost heave mechanism of CGF. The results indicate that the liquid water in CGF is discontinuous and difficult to migrate to the freezing front. The primary mechanism of moisture accumulation and frost heave in CGF is vapor migration and phase transition. With increasing freeze-thaw cycles, both vapor migration and frost heave reduce. The thaw settlement of the CGF is less than the frost heave, so there is a net upward deformation in each cycle. Furthermore, the fine particle content has a prominent effect on the heat transfer and frost heave of the CGF compared to the fine particle type. Even under the condition of vapor replenishment, controlling the content of fine particles is still an important way to inhibit frost heave. Moreover, after reducing the maximum particle size of CGF, the frost heave of the sample increases. Nuclear magnetic resonance (NMR) test results show that CGF is dominated by large pores, and the freeze-thaw cycle further promote the development of large pores, providing a good channel for the migration of vapor. In conclusion, the frost heave development caused by vapor migration is slow and continuous, posing a non-negligible risk to HSR subgrades during long-term service.

Unlike many biopolymers, alpha-1,3-glucan (alpha-1,3-GLU) is water-insoluble, making it a promising candidate for the production of moisture-resistant films with applications in biodegradable packaging, biomedicine, and cosmetics. This study aimed to characterize the structural, physicochemical (water affinity, optical, mechanical), and biodegradation properties of a film made from alpha-1,3-GLU extracted from Laetiporus sulphureus. The film was fabricated through alkaline dissolution, casting, drying, washing to remove residual NaOH, and re-plasticization with a glycerol solution. FTIR and Raman spectroscopy confirmed the polysaccharide nature of the film, with predominant alpha-glycosidic linkages. The film exhibited a semi-crystalline structure and high opacity due to surface roughness resulting from polymer coagulation. Owing to re-plasticization, the film showed a high moisture content (similar to 47%), high water solubility (81.95% after 24 h), and weak mechanical properties (tensile strength = 1.28 MPa, elongation at break approximate to 10%). Its water vapor permeability (53.69 g mm m(-2) d(-1) kPa(-1)) was comparable to other glycerol-plasticized polysaccharide films reported in the literature. The film supported the adhesion of soil microorganisms and target bacteria and was susceptible to degradation by Trichoderma harzianum and endo- and exo-alpha-1,3-glucanases, indicating its biodegradability. The limitations in its mechanical strength and excessive hydration indicate the need for improvements in the composition and methods of producing alpha-1,3-GLU films.

Expansive soils are susceptible to cracking due to significant moisture fluctuations, which can potentially lead to structural instability. Although geogrid reinforcement is widely used to control soil swelling and shrinkage, its effects on cracking behavior are not fully understood. This study investigates the influence of geogrid reinforcement on the cracking behavior of expansive soils by comparing soil samples reinforced with two layers of geogrid to unreinforced samples under evaporation conditions. Crack development was monitored using high- resolution imaging and fluorescence tracing to measure crack depth and calculate surface crack ratio. Additionally, moisture content distribution and evaporation rates were assessed. The results show that geogrid reinforcement reduced the total crack ratio by 1.34% and decreased average crack depth by 43.5%, leading to a more uniform crack distribution with smaller openings. Both internal and external cracks facilitated moisture exchange between the soil and atmosphere. The frictional and interlocking effects at the soil-geogrid interface effectively inhibited cracking and reduced moisture migration. The uniaxial geogrid also induced anisotropy crack restraint, with environmental exposure and geogrid orientation playing critical roles in crack control. Overall, these findings demonstrate the effectiveness of geogrids in enhancing the stability of expansive soils and limiting atmospheric influence through crack suppression.

Severe scaling and spalling are commonly observed on tunnel lining surfaces in sulfate-rich environments. Due to humidity gradients, sulfate solution in rock fissures migrates through capillary action to the concrete exposed face, leading to physical crystallization precipitation at free-face zone and chemical sulfate attack at soil-facing zone, resulting in concrete expansion and crack. Existing models focus on full immersion or wet-dry cycles, which have obvious errors in predicting concrete damage under similar partial immersion. Considering the time- varying characteristics of saturation, porosity, calcium leaching and crack, a transport-reaction-expansion model for lining concrete under dual sulfate attacks and water evaporation was established. The spatiotemporal distribution of phase composition and the influence of modeling parameters on concrete expansion were revealed. The expansion strain caused by dual sulfate attacks and changes in the water evaporation zone was discussed. These findings provide a theoretical foundation for the durability design of lining concrete in sulfate- rich environment.

The objective of the present work was to investigate the effect of CMC biopolymer on the physicochemical, mechanical, thermal, barrier, and biodegradation properties of PVA-based films. The polymeric films were developed using solution casting method, incorporating CMC at concentrations ranging from 0.5 to 1.5%. With the addition of CMC, the tensile strength (TS) of the hybrid films was reduced from 1.40 +/- 0.02 MPa to 1.99 +/- 0.02 MPa. However, there was a significant improvement in the elongation at break (EAB) up to 49.29% compared to PVA film. The addition of CMC resulted in substantial improvements in water vapor permeability (WVP) and moisture retention capacity (MRC), showcasing a 38.73% improvement in WVP and a satisfactory MRC of 78.374% at 0.5% CMC concentration. The hybrid films also exhibit enhanced light absorbance at UV wavelength with opacity ranging from 0.301 to 1.413. TGA analysis showed a notable enhancement in the decomposition temperature of the hybrid PVA/CMC films, resulting in reduced mass loss compared to the PVA film. FTIR spectra confirmed that blending CMC with PVA led to the formation of strong hydrogen bonds within the polymer blend, significantly affecting the intermolecular forces inside the cellulose matrix. Moreover, with the addition of CMC, the degradation rate of the PVA/CMC film was increased approximately to 40% on the 30th day of soil burial. The films also exhibit effective microbial degradation against Pseudomonas putida and Bacillus subtilis bacteria strains as compared to commercial plastics. Overall, the obtained results validate the use of CMC biopolymer for blending of single polymer system as well as scaling down the extensive use of petroleum-based polymers in the field of packaging.

The present work investigates the development and characterization of cellulose acetate (CA) films with varying concentrations of CA, incorporating glycerol as a plasticizer and calcium chloride (CaCl2) as a crosslinker. The films were fabricated using solution casting and phase inversion techniques. The inclusion of glycerol significantly enhanced the surface morphology, tensile strength (TS), and elongation at break (EAB) of the films. The optimal composition, containing 10% (w/v) CA and 1% (v/v) glycerol, achieved the highest TS (3.199 +/- 0.077 MPa) and EAB (9.500% +/- 0.401%). The addition of CaCl2 to CA resulted in improved thermal properties of the films, suggesting effective crosslinking between CA and glycerol, as demonstrated by the DSC and TGA analyses. FTIR analysis suggested that glycerol interacts with cellulose, through hydrogen bonding, modifying the intermolecular forces within the cellulose matrix. Glycerol also improved the films' hydrophilicity and reduced swelling, solubility, and water contact angle (WCA). The films also exhibited antimicrobial properties against Staphylococcus aureus (S. aureus), a gram-positive bacterium, and achieved a soil biodegradation rate of 43.65% within 30 days. These results suggest that CA films with optimized glycerol and CaCl2 are promising for various industrial and medical applications where enhanced mechanical properties, permeability control, and biodegradability are essential.