Search Results (545)

This study investigated the use of Marine Recyclable Aggregate (MRA), synthesized from Recycled Particles from Paste (RPPs) obtained from construction waste, seawater, and alkali activator (Na₂O∙3.3SiO₂, NS), for reinforcing marine soft clay. RPP is a laboratory-prepared material used to simulate construction waste. The physicochemical properties of MRA were characterized using X-ray diffraction (XRD), thermal field emission scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and thermogravimetric analysis (TGA). The results revealed that the key hydration products in MRA are Friedel’s salt (3CaO·Al₂O₃·CaCl₂·10H₂O, FS), xCaO·SiO₂·nH₂O (C-S-H), and CaO·Al₂O₃·2SiO₂·4H₂O (C-A-S-H). The formation of these hydration products enables MRA to maintain stability in marine environments. The deformation characteristics of MRA-reinforced soft clay under various conditions were investigated by integrating X-ray computed tomography with triaxial compression tests, allowing for the three-dimensional visualization and reconstruction of the failure process. The application of MRA for soft clay reinforcement in seawater environments enhances the bearing capacity of the clay and provided significant environmental benefits. Full article

Portland cement (PC) is widely regarded as a cost-effective and reliable binding material for the stabilization and solidification of municipal solid waste incineration fly ash (MSWI FA). However, the soluble salts and heavy metals present in MSWI FA retard PC hydration, thereby limiting the amount of fly ash that can be incorporated. The present study investigates the feasibility of normalizing the hydration of PC-based mixtures containing MSWI FA by applying a fly ash pre-granulation step with 25% PC, followed by coating the resulting granules with a geopolymer layer to reduce the release of harmful ions during the early stages of hydration. Isothermal calorimetry, TG/DTA, XRD, SEM, and mechanical testing were used to investigate the hydration characteristics of composites containing such granules and to assess their properties at 7, 28, and 90 days. It was found that a 20% substitution of PC with the studied FA disrupted PC hydration within the first 48 h. In contrast, both types of granules exhibited the main exothermic peak within the first 10–12 h, with hydration heat release (about 300 J/g) comparable to that of sand-containing references. Uncoated granules exhibited more active behavior with hydration kinetics similar to pure cement paste, whereas the effect of geopolymer-coated granules was close to sand. TG/DTA revealed reduced calcite content in mixtures containing granules, whereas uncoated granules promoted greater portlandite formation than the sand-based system. Hardening the samples under wet conditions resulted in the development of a dense cement matrix, firm integration of the granules, redistribution of chlorine and sulfur ions, and mechanical properties that reached at least 93% of those of the sand-containing reference, despite a lower density of ~4.5%. Full article

Coalbed methane development is constrained by reservoir characteristics including high gas adsorption, high salinity, and high closure pressure, which impose significant limitations on conventional polymer fracturing fluids regarding viscosity enhancement, proppant transport, and fracture maintenance. In this study, a novel polymer fracturing fluid system, Z-H-PAM, was designed and synthesized to achieve strong salt tolerance, low adsorption affinity, and high elasticity to withstand closure pressure. This was accomplished through the molecular integration of a zwitterionic monomer ZM-1 and a hydrophobic associative monomer HM-2, forming a unified structure that combines rigid hydrated segments with a hydrophobic elastic network. The results indicate that ZM-1 provides a stable hydration layer and low adsorption tendency under high-salinity conditions, while HM-2 contributes to a high-storage-modulus, three-dimensional physically cross-linked network via reversible hydrophobic association. Their synergistic interaction enables Z-H-PAM to retain viscoelasticity that is significantly superior to conventional HPAM and to achieve rapid structural recovery in high-mineralization environments. Systematic evaluation shows that this system achieves a static sand-suspension rate exceeding 95% in simulated flowback fluid, produces broken gel residues below 90 mg/L, and results in a core damage rate of only 10.5%. Moreover, it maintains 88.8% of its fracture conductivity under 30 MPa closure pressure. Notably, Z-H-PAM can be prepared directly using high-salinity flowback water, maintaining high elasticity and sand-carrying capacity while enabling fluid recycling and reducing reservoir damage. This work clarifies the multi-scale mechanisms of strongly hydrated and highly elastic polymers in coalbed methane reservoirs, offering a theoretical and technical pathway for developing efficient and low-damage fracturing materials. Full article

2,3,5-triphenyl-2H-tetrazol-3-ium (TPT) chloride was studied through a combination of theoretical methods and experimental data, revealing structural and physical-chemical properties of the hydrate salt, [TPT]Cl·H₂O. The previously reported crystal structure was confirmed, but our study at lower T (100 K vs. 220 K) showed different positions for the two H₂O molecules in the unit cell around the chlorides. One of them (Cl1) is found surrounded by the tetrazole units, which we call the “dry pocket”, in contrast to the other, Cl2, which is involved in a hydrogen bonding cluster that consists of chloride and two water molecules, referred to as the “wet pocket”. Hirshfeld surface analyses showed predominant H⋯H interactions, followed by C⋯H interactions (including C–H⋯Cl/O interactions), and H⋯Cl contacts, which represent the C–H⋯Cl2 hydrogen bonds. Density functional theory (DFT) and (time-dependent) TD-DFT calculations on a molecular model of the compound, benchmarking the three functionals B3LYP, CAM-B3LYP, and PBE1PBE, found excellent agreement with experimental solution data when using the CAM-B3LYP function. UV-Vis absorptions observed at 320 nm, 245 nm, and 204 nm (in MeOH solution) were quite accurately reproduced and assigned. The observed bands were assigned to mixed HOMO–n⟶LUMO+m transitions, involving in all cases the LUMO+1 for the most intense band at 245 nm. Solid-state calculations on the GGA (PBE) level of theory using the CASTEP code and including the Tkatchenko–Scheffler (TS) scheme for the description of long-range interactions gave a good match for the calculated electronic band gap in the solid-state of 3.54 eV compared with the experimental value of 3.12 eV obtained through the Tauc plot method. Full article

The safe disposal of high-level radioactive waste (HLW) is a significant challenge in the nuclear industry. As the buffer backfill material for deep geological disposal engineering barriers, the shrinkage characteristics of bentonite–sand mixtures are critical to the long-term stability of repositories. This study systematically conducted drying shrinkage tests using an improved thin-film technique under varying sand contents R_s (0–50%), salt solution concentrations (0–1.5 mol/L), and ion types (Na⁺, Mg²⁺, Ca²⁺, Cl⁻, SO₄²⁻). The mechanisms of the effects of sand content and salt solutions on the shrinkage behavior of bentonite were revealed based on the results. In addition, the rationality of the MCG-B model in simulating the shrinkage characteristics of mixtures was also discussed. The results show that a sand content of 30% is the minimum sand content for inhibiting the shrinkage behavior of bentonite–sand mixtures observed in this work: below this ratio, bentonite dominates the shrinkage process, and samples are prone to cracking due to uneven matrix suction; above this ratio, quartz sand forms a rigid skeleton that significantly inhibits volume shrinkage and accelerates water evaporation. Salt solutions suppress shrinkage by compressing the thickness of the diffuse double layer and inducing ion crystallization. Higher cation concentrations and valences (Mg²⁺ > Na⁺ > Ca²⁺) enhance the inhibitory effect. Crystalline salts such as Na₂SO₄ cause measurement deviations in water content due to hydration and delay the shrinkage process. However, NaCl solutions effectively inhibit shrinkage with minimal impact on shrinkage time. Fitting results with the MCG-B model (Coefficient of determination > 0.97) demonstrate that the MCG-B model can empirically describe the results of thin-film technique experiment, though the model’s prediction accuracy decreases for the residual shrinkage stage at high sand contents (>40%). This study provides a theoretical basis for optimizing buffer material proportions and curing processes, with significant implications for the long-term safety of HLW repositories. Full article

Adiabatic demagnetization refrigeration (ADR) is regaining relevance for refrigeration to temperatures below 1 K as global helium-3 supply is increasingly strained. While ADR at these temperatures is long established with paramagnetic hydrated salts, more recently, frustrated rare-earth oxides were found to offer higher entropy densities and practical advantages, since they do not degrade under heating or evacuation. We report structural, magnetic, and thermodynamic properties of the rare-earth borates Ba₃XB₉O₁₈ and Ba₃XB₃O₉ with X = (Yb, Gd). Except for Ba₃GdB₉O₁₈, which orders at 108 mK, the three other materials remain paramagnetic down to their lowest measured temperatures. ADR performance starting at 2 K in a field of 5 T is analyzed and compared to literature. Full article

Dehumidification plays a vital role across industrial, commercial, and residential settings, where controlling moisture is essential for maintaining air quality, protecting materials, and ensuring comfort. Calcium chloride (CaCl₂) is a widely used, low-cost desiccant, but it suffers from a critical drawback: under humid conditions, particles tend to agglomerate, which reduces their ability to absorb water. In addition, when the salt dissolves in hydration water, its contact surface with moist air decreases, and corrosive liquid leakage can occur. Embedding CaCl₂ into hydrophilic porous matrices offers a solution by dispersing particles more effectively, preventing agglomeration, increasing the contact area, and retaining liquid within the pore network to suppress leakage. In this study, we introduce a novel approach for fabricating carbon-based foams impregnated with CaCl₂, produced through the thermal decomposition of glucose under self-induced pressure. These foams exhibit a composite architecture that integrates CaCl₂ and calcium carbonate, enabling controlled porosity through selective dissolution. Importantly, the in situ transformation of CaCl₂ into calcite refines the internal structure, improving both stability and acids absorption performance. FTIR confirmed the strong hydrophilicity of the foam walls, which enhances water vapor uptake while preventing leakage of saturated salt solutions. The carbon matrix further suppresses salt particle agglomeration during moisture absorption, resulting in high efficiency. These multifunctional foams not only capture water vapor and volatile acids but also show potential as phase change materials. Mechanical testing revealed tunable behavior among the fabricated foams, ranging from high-stiffness structures with superior energy absorption (e.g., C2) to more compliant foams with extended strain capacity (e.g., A2), illustrating their versatility for practical applications. Full article

Soil salinity poses a major threat to agriculture by severely limiting how well plants grow and produce crops. It strongly inhibits seed germination, a critical stage for plant life. Thus, it is critical to understand the complex ways salinity affects seed germination at the physiological, biochemical, and molecular levels to develop effective salt stress mitigation strategies. This review synthesizes the underlying mechanisms of how salinity inhibits seed germination, the observed impacts of this inhibition, and potential mitigation strategies. The review revealed that high salt concentrations reduce seed germination percentage and increase germination time through multiple mechanisms. They create osmotic stress that reduces water uptake, cause ion toxicity that disrupts critical metabolic activities, and induce oxidative stress. Furthermore, salinity can modify endogenous hormonal profiles, specifically by decreasing germination stimulants like gibberellic acids while increasing inhibitors like abscisic acid. The review finally explored the strategies to mitigate salinity’s adverse effects on seed germination. They include seed priming, a technique involving partial hydration of seeds in an eliciting solution, a promising biotechnological tool to overcome salinity problems during seed germination. Other approaches are the use of organic amendments and the breeding of salt-tolerant varieties. Future research should combine conventional and advanced molecular technologies to develop salt-tolerant cultivars to ensure food security in salt-affected agricultural lands. Full article

Adequate hydration is essential for health, yet the contribution of water from food (WFF) to total water intake (TWI) and its determinants remain unclear in China. This study quantified WFF and explored factors influencing its variation among young Chinese adults. A multicentre cross-sectional survey was conducted in May–June 2023 among 947 healthy adults aged 18–25 years from seven regions of China. WFF was measured using three-day duplicate food portions, and drinking fluid intake was recorded with a validated 24 h diary. Sociodemographic, dietary, behavioral, and psychological data were collected using standardized instruments. Multivariable linear regression, stratified by sex and age, examined associations with WFF and its proportion of TWI. On average, WFF accounted for 38.0% of TWI, with regional variation from 33.5% in southern China to 44.3% in eastern China. Higher daily intake of energy, salt, and carbohydrate intakes were each positively associated with greater WFF, while carbohydrate intake seemed to betas the strongest predictor of a higher proportion of WFF. Younger age and elevated anxiety showed modest independent associations. These findings indicate that WFF contributes substantially to hydration in Chinese young adults, primarily driven by dietary composition. Recognizing WFF in hydration guidelines could improve population assessments and inform evidence-based nutrition strategies in China and other high-moisture diet regions. Full article

Polyampholytes combine cationic and anionic groups in one macromolecular platform and are emerging as versatile components for energy storage and conversion. This review synthesizes how their charge balance, hydration, and architecture can be engineered to address ionic transport, interfacial stability, and safety across batteries, supercapacitors, solar cells, and fuel cells. We classify annealed, quenched, and zwitterionic systems, outline molecular design strategies that tune charge ratio, distribution, and crosslinking, and compare device roles as gel or solid electrolytes, eutectogels, ionogels, binders, separator coatings, and interlayers. Comparative tables summarize ionic conductivity, cation transference number, electrochemical window, mechanical robustness, and temperature tolerance. Across Li and Zn batteries, polyampholytes promote ion dissociation, homogenize interfacial fields, suppress dendrites, and stabilize interphases. In supercapacitors, antifreeze hydrogels and poly(ionic liquid) networks maintain conductivity and elasticity under strain and at subzero temperature. In solar cells, zwitterionic interlayers improve work function alignment and charge extraction, while ordered networks in fuel cell membranes enable selective ion transport with reduced crossover. Design rules emerge that couple charge neutrality with controlled hydration and dynamic crosslinking to balance conductivity and mechanics. Key gaps include brittleness, ion pairing with multivalent salts, and scale-up. Opportunities include soft segment copolymerization, ionic liquid and DES plasticization, side-chain engineering, and operando studies to guide translation. Full article

In this study, the potential use of Epsom salt production waste as a supplementary cementitious material was investigated. This acidic waste was neutralized with lime milk and used to replace up to 25 wt.% of Portland cement. The following research methods were employed: XRD, XRF, SEM, DSC-TG, and isothermal calorimetry. The waste neutralization process was found to proceed consistently, producing a neutral material (pH = 7.5) composed of amorphous silicon compounds with a negligible impurity of crystalline antigorite. Consequently, this material exhibits very high pozzolanic activity. The neutralized Epsom salt production waste accelerates the early hydration of Portland cement and promotes an intense pozzolanic reaction. This new material is a highly effective supplementary cementitious material, capable of replacing up to 25 wt.% of Portland cement without reducing its strength class. Full article

The role of ethylene in the adaptation of Arabidopsis thaliana to salt stress induced by 150 mM NaCl is investigated. The responses of wild-type (Columbia, WT) plants and ethylene-insensitive etr1-1 mutants to short-term daily salt treatments were compared. Parameters analyzed included growth, water status, chlorophyll content, and hormone levels (ABA, IAA, cytokinins) using ELISA and immunohistochemistry. The results revealed that in the WT, salt stress induced hormonal redistribution: accumulation of ABA, IAA, and zeatin in shoots, accompanied by decreased ABA in the root tips and cytokinins in the whole roots. These hormonal changes were associated with stomatal closure, maintained leaf hydration, and inhibition of root growth. The inhibition of root growth may contribute to reduced uptake of toxic ions from the environment. In contrast, etr1-1 mutants exhibited no changes in hormonal status, failed to close stomata—leading to decreased leaf water content—and showed a sharp decline in chlorophyll content accompanied by suppressed shoot growth. The conclusions emphasize that ethylene sensitivity is essential for initiating adaptive hormonal rearrangements that coordinate growth and stomatal responses to mitigate the effects of salt stress. Full article

Salt stress significantly reduces plant growth and yield, which has led to extensive research on the mechanisms underlying plant salinity tolerance. Carrot (Daucus carota ssp. sativus) is a glycophyte highly sensitive to soil salinity. We investigated root and leaf anatomical, histological, and immunohistological alterations in two carrot accessions, previously identified as salt-sensitive (DH1) and salt-tolerant (DLBA), growing under control and salt stress conditions. The results demonstrate that the salt-tolerant DLBA growing under control conditions has trichome-rich leaves, high starch reserves and a hydraulically safer root xylem. Under salt stress, DLBA maintains mesophyll integrity, and increases the number of vessels and deposition of highly esterified pectins, hemicelluloses and spatially regulated AGPs in cell walls. In contrast, DH1 develops thinner, trichome-free leaves, and roots almost free of starch with fewer cambial cells and vessels. Salt stress induces overexpansion of palisade parenchyma, excess starch accumulation, loss of arabinan epitopes, disappearance of extensins in vascular bundles, and changes in hemicellulose and AGP distribution. These findings indicate that salt tolerance of DLBA plants results from the combination of constitutive anatomical characteristics and adaptive responses that together support tissue hydration, wall elasticity and stable water transport when plants are growing in saline soil. Full article

Combining different materials into binary salts can significantly enhance the efficiency and stability of Thermochemical Energy Storage (TCES) systems. This study aimed to develop and characterise novel salt hydrate composite materials for TCES, focusing on a mixture of magnesium chloride (MgCl₂) and calcium chloride (CaCl₂) impregnated into a mesoporous silica gel (SG) sphere matrix. Three different MgCl₂/CaCl₂ salt ratios were investigated to find the optimal balance between sorption capacity and stability against deliquescence in humid environments. Prepared samples underwent comprehensive characterisation, including structural and morphological analysis, water vapour sorption and heat capacity measurements. The hybrid CaCl15/MgCl15/SG sample exhibited intermediate behavior between the pure CaCl30/SG and MgCl30/SG samples, with significantly improved stability in a humid environment due to the addition MgCl₂. Characterisation revealed the effective confinement of the salt mix in the matrix. The optimised CaCl15/MgCl15/SG sample demonstrated highly promising gravimetric and volumetric energy storage capacities of 1092 J/g and 2.3 MJ/m³, respectively, comparable to recently reported composites. The material sorption dynamics were ultimately tested in a whole adsorbent unit under near-real-world operating conditions, pushing the research to the reactor and system level, and demonstrating that the presence of MgCl₂ in the composite does not adversely affect the adsorption kinetics compared to the pure CaCl₂-based composite. Full article

Thermal energy storage using latent heat storage materials represents a promising solution for stabilizing low-temperature energy systems; however, its effectiveness is limited by the low thermal conductivity of phase change materials (PCM), particularly salt hydrates such as sodium acetate trihydrate (SAT). The objective of this work is to analyze to what extent vertical gradation of a metallic gyroid structure can enhance heat transfer and temperature homogeneity in the PCM during charging. Time-dependent numerical simulations of conjugate heat transfer were performed for three gyroid variants differing in the orientation of pore gradation, modeling heat transfer between the flowing water, the aluminum gyroid structure, and the solid phase of SAT until the PCM reached a temperature of 58 °C. The results showed that the orientation of the gradation significantly affects both the heating dynamics and the quality of the temperature field. The variant with enlarged pores in the region of contact with the fluid and gradually decreasing pores toward the PCM achieved the shortest time to complete heating, the lowest temperature amplitude, and the highest degree of temperature homogeneity. This variant also exhibited the highest energetic efficiency, expressed as the ratio of transferred heat to pressure drop. The study demonstrates that deliberately designed gyroid gradation can substantially improve the performance of PCM composites without increasing the amount of material and represents a promising pathway for the development of advanced thermal storage systems. Full article