Search Results (2,091)

This study aims to investigate the influence of clay mineral content on the rheological properties and long-term deformation stability of clays, and to establish a unified model capable of quantitatively describing the nonlinear rheological behavior of clays with different mineral compositions. Direct shear rheological tests were conducted on specimens prepared with different mixing ratios of bentonite, kaolin, and quartz. Combined with micro-mechanism analysis, the controlling factors of clay rheological behavior were explored. The experimental results show that the creep stress threshold, elastic viscosity, and average plastic viscosity decrease significantly with increasing clay mineral content. The rheological deformation exhibits distinct nonlinear characteristics, and clay mineral content plays a controlling role in the rheological behavior. Based on experimental and mechanistic analysis, a unified rheological model was established, which reflects the material origin of rheology and captures nonlinear rheological characteristics. This model can predict the entire time-history mechanical behavior of clays with different mineral compositions across the three stages of instantaneous deformation, decay rheology, and steady-state rheology under different shear stress levels using a single set of parameters. Validation was performed through direct shear rheological tests under 50 working conditions for five types of clay specimens, demonstrating good consistency between the model calculations and experimental results. The unified rheological model reveals the material origin and physical essence of clay rheology, demonstrates high universality, and advances the understanding of the influence of mineral composition on rheology from the current phenomenological qualitative description to quantitative calculation for the first time, significantly enhancing its engineering application value. This provides a more reliable tool for predicting long-term deformation and assessing the stability of clay foundations. Full article

To investigate the sulfate corrosion resistance of cast-in-place repair concrete incorporating recycled coarse aggregate (RCA) under partially exposed conditions, cast-in-place repair concrete specimens with different RCA contents (0%, 30%, and 50%) were immersed in Na₂SO₄ solution. The study systematically investigated the changes in apparent morphology, dimensions, mass, and mechanical properties of the specimens under sulfate corrosion. SEM, XRD, TG/DTG, and MIP were used to characterize the microstructure and mineral composition of the specimens at different corrosion ages. Results indicate that RCA cast-in-place repair concrete partially exposed to a sulfate corrosion environment undergoes coupled physical and chemical corrosion, and the interfacial zone between the recycled aggregate concrete to the base concrete represents the most vulnerable region in the composite system. Incorporating 30% RCA can effectively reduce the degradation rate of specimens under sulfate corrosion, enhance the compactness of the bonding interface, and optimize the interfacial bond strength, compressive strength, and pore structure of the specimens. Excessive RCA content disrupts the internal pore structure, accelerates sulfate ion ingress, and weakens the interfacial bond strength. The presence of RCA significantly reduces the interfacial shear strength of the specimens. After 360 days of sulfate corrosion, specimens featuring 30% and 50% RCA contents exhibit a reduction in shear strength of 15.91% and 40.0%, respectively, compared with the 0% RCA content specimen. Research findings provide a theoretical basis for the application of RCA in concrete repair engineering. Full article

With its excellent physical and mechanical properties, granite is often the first choice for the foundation material for dams in water conservancy engineering. However, alteration can profoundly change the mineral composition, structure, and mechanical behavior of deep granite, posing critical challenges to project safety. The Quwu Mountain area in Baiyin, Gansu Province, a proposed pumped storage reservoir, exposes extensive Silurian granite. Engineering investigation shows that different levels of clay and hydrothermal alteration have taken place in the granite rock mass, and the level of alteration exhibits a distinct vertical zonation as revealed by borehole core logging. In this study, we quantitatively characterize the porosity, compressive strength, wave velocity, and shear parameters of altered granite of different degrees through mineralogical analysis, laboratory tests, and in situ testing. In order to guide the construction in this area, we establish a classification system that distinguishes weak, moderate, and strong alteration degree, based on macroscopic features, RQD, and clay mineral content. Results of this paper show that alteration is dominated by potassium feldspathization and kaolinitization, leading to increased porosity (4–10%) and structural loosening. Strongly altered granite exhibits severe mechanical degradation, moderately altered granite retains medium strength, and weakly altered granite approaches the properties of fresh rock. This research can provide technical support for engineering safety design and risk prevention in the Quwushan reservoir area, but its applicability to other regions requires further validation. Full article

This study evaluated the growth performance, carcass characteristics, and meat quality of male Alpine and Saanen goat kids raised under standardized fattening conditions to inform breed-specific strategies for meat production. The study included 36 single-born male kids (18 Alpine and 18 Saanen purebreds) of similar age and live weight. The animals were allocated by breed and randomly assigned to three replicates per breed, with six animals in each replicate. After a two-week adaptation period, the kids were fattened for 12 weeks on an 80:20 concentrate–roughage diet. At the end of the fattening period, all animals were slaughtered, and physical, sensory, and chemical analyses of the meat were performed on the Longissimus lumborum (LL) muscle. Final live weights did not differ significantly between Alpine and Saanen kids, nor did average daily gains. However, the feed conversion ratio favored the Saanen breed, indicating superior feed efficiency. Alpine kids had significantly higher internal fat content, while Saanen kids had a higher proportion of full intestines. Meat pH, color, and texture were similar between breeds. Fatty acid analysis showed that Alpine meat had higher palmitic and palmitoleic acid content, whereas Saanen meat contained more calcium and sodium. These results suggest that both breeds are suitable for high-quality meat production under controlled feeding conditions, but breed-specific differences in fat composition and mineral content may affect nutritional value and market positioning. These findings are valuable for optimizing selection and marketing strategies in goat meat production systems targeting diverse consumer demands. Full article

Fatigue and reduced energy availability significantly affect athletic performance, and nutritional strategies to maintain carbohydrate and electrolyte levels are critical for delaying fatigue and preserving endurance. This study aimed to evaluate the effects of carbohydrate and electrolyte (CHO-E) supplementation on sports performance in physically active individuals. A systematic review and meta-analysis of 26 studies, including randomised and observational designs, was conducted. Four separate analyses examined the impact of CHO-E supplementation on performance outcomes, metabolic biomarkers, blood mineral concentrations, and additional performance descriptors. The meta-analysis showed that CHO-E supplementation significantly increased time to exhaustion (Standard Mean Difference (SMD) 0.60; 95% confidence interval (CI): 0.17, 1.02; p = 0.006), blood glucose levels (SMD 0.82; 95% CI: 0.45, 1.19; p < 0.001), and blood sodium levels (SMD 0.22; 95% CI: 0.07, 0.36; p = 0.004) compared to placebo, while no significant effect was observed for time to finish (SMD −0.07; 95% CI: −0.28, 0.13; p = 0.49). These findings indicate that CHO-E supplementation during moderate-to-high intensity exercise can enhance performance by extending endurance and supporting metabolic and electrolyte balance. Overall, the results support the targeted use of CHO-E supplementation to maintain energy availability and physiological stability during prolonged physical activity, providing evidence-based guidance for athletes and practitioners. Full article

Industrial activities have caused heavy metals, such as cadmium (Cd), chromium (Cr), lead (Pb), and copper (Cu), to seriously threaten groundwater safety through seepage pathways. This study explored the formation of biofilms using microbe-induced calcium carbonate precipitation (MICP) technology to simultaneously reduce seepage in contaminated water and immobilize heavy metals. By optimizing the cementation fluid concentration and the intermittent grouting time, the optimal operating conditions for forming a biofilm were determined to be 1.5 mol/L cementation fluid and an intermittent time of 12 h, under which the stable infiltration rate of the sandy loam soil column can be reduced by more than 80%. We found that this biofilm can effectively inhibit the convective transport of Cd, Cr, Pb, and Cu, with the cumulative convective flux reduction rates reaching 56.25%, 56.25%, 54.54%, and 55.59%, respectively. SEM and XRD analysis indicate that the physical blockage of soil pores by calcium carbonate crystals is the dominant mechanism controlling infiltration flow, while the detection of new mineral phases, such as lead carbonate (PbCO₃), cadmium carbonate (CdCO₃), and basic copper carbonate (Cu₂(OH)₂CO₃) provides direct evidence for the chemical co-precipitation immobilization of heavy metals. This study demonstrates that MICP biofilm is a green and sustainable technology for in situ remediation of heavy metal pollution through physical–chemical synergistic effects, offering a promising alternative with a lower environmental footprint compared to conventional methods. Full article

Research on shale reservoir characteristics and the controlling factors of gas content is critical for predicting shale gas “sweet spots”. Based on integrated geochemical, mineralogical, and petrophysical analyses, this study investigates the mineral composition of shale and the influencing factors of gas content in the Chang 7 Member of the Ordos Basin. The results show that (1) the shale clasts are mainly composed of quartz and feldspar, with the quartz contents in the range of 10.6%–29.7%, the feldspar contents in the range of 5.2%–38.2%, and the clay mineral contents in the range of 25.0%–70.5%. (2) The shale pore types include intergranular pores, granular dissolved pores and organic matter pores. The shale pores are mainly mesoporous and the pore sizes are mainly 6–9 nm with an average of 7.2 nm, accounting for 50% of the total pores population. (3) The shale kerogen maceral assemblage is composed primarily of the sapropel group, accounting for 77.2%–94.9% of the total macerals; vitrinite reflectance ranges from 0.80% to 1.13%, with a mean value of 0.83%. (4) The gas content of shale reservoirs is mainly controlled by temperature, pressure, total organic carbon (TOC) content, vitrinite reflectance, and reservoir physical properties. Among them, medium-to-large pores, TOC content, and pressure are the main controlling factors of shale gas content. The clay mineral content, vitrinite reflectance, and gas content constitute secondary controlling factors. Full article

Oxidative stress is a hallmark of carcinogenesis, yet the epigenetic mechanisms linking the lifestyle-based Oxidative Balance Score (OBS) to cancer risk remain poorly understood. This study investigated the epigenetic bridge between OBS and pan-cancer susceptibility using a multi-cohort approach integrating population-based and cancer genomic data. We calculated OBS based on 16 dietary and lifestyle factors (including dietary fiber, vitamins, minerals, physical activity, smoking, alcohol, and BMI) for 2749 participants from the Korean Genome and Epidemiology Study (KoGES) and identified OBS-associated CpG sites via epigenome-wide association analysis. These markers were validated against The Cancer Genome Atlas (TCGA) pan-cancer dataset using a novel Hybrid Pi-score (HyPi) to quantify the directional consistency between OBS-driven methylation in healthy individuals and cancer-specific epigenetic alterations across three clinical comparisons: normal vs. tumor, survival outcomes, and tumor stage. We observed profound sex-specific epigenetic signatures, with zero overlap in the top 200 OBS-associated CpG sites between males and females, underscoring fundamental sexual dimorphism in oxidative stress-epigenome interactions. Notably, the top 20 OBS-associated CpGs demonstrated strong directional consistency with multiple cancer types in TCGA, particularly in kidney renal clear cell carcinoma and lung adenocarcinoma, exhibiting methylation patterns inversely correlated with tumorigenesis. Mechanistically, these findings support the role of one-carbon metabolism and vitamin C-dependent DNA demethylation pathways in mediating OBS effects. Our study provides the first evidence of an epigenetic link between lifestyle-based oxidative balance and pan-cancer risk, highlighting the utility of the HyPi score as a novel sex-specific predictive biomarker for cancer prevention. These results suggest that optimizing oxidative balance through precision nutrition may epigenetically modulate cancer susceptibility, opening new avenues for personalized prevention strategies. Full article

In the fragile Loess Plateau ecosystem, straw return is a key measure to improve its low soil organic matter. However, the short-term carbon retention efficacy of straw return, which depends on the initial balance between carbon mineralization and sequestration, remains unclear across different soil textures. This study investigated the short-term impacts of straw return on organic carbon fractions in three soils with varying textures via laboratory incubation. Results showed that while straw return universally increased active organic carbon pools, its accumulation in the mineral-associated organic carbon (MAOC) pool was texture-dependent. Straw incorporation, especially maize straw, effectively promoted MAOC formation in clayey soils (Phaeozems and Anthrosols) with large specific surface areas. Conversely, in Arenosols, carbon was retained in active pools, limiting long-term retention potential. The mechanism involves a combined regulation by soil physicochemical properties, where clay content and specific surface area are fundamental physical drivers for MAOC accumulation, synergistically influenced by chemical factors like pH and electrical conductivity through processes such as cation bridging. These findings provide critical scientific evidence for developing texture-specific straw return management strategies for the Loess Plateau. Full article

The chemical and mineral composition, physical and mechanical properties, and pozzolanic activity of ancient bricks from Hubei Province, China were investigated in this study. X-ray diffraction (XRD), thermogravimetric analysis (TG-DSC), X-ray fluorescence analysis (XRF) and scanning electron microscopy–energy dispersive spectroscopy (SEM-EDS) were adopted to characterize the chemical composition, crystalline minerals and microstructure of the ancient bricks. The results show that quartz is the dominant component in most ancient bricks, with a content exceeding 70% in samples BB-2, BB-5, BB-6 and BB-7. Some bricks contain minor non-clay minerals such as calcite, dolomite and albite. On some points in the SEM image, substances such as gypsum, calcite, and quartz can be clearly seen. The calcining temperature of the ancient bricks from Yupan Village, Xiantao City (sample BB-1), does not exceed 600 °C, while that of other samples ranges from 800 to 1100 °C. The compressive strength of most ancient bricks is around 10 MPa, with the highest value of 14.3 MPa (BB-6) and the lowest of 1.2 MPa (BB-3). The apparent density of all samples is approximately 2.2 g/cm³, and the water absorption rate ranges from 6.5% to 23.1%. The pozzolanic activity index of some samples reaches 76% at 28 days, with the 150-year-old sample BB-7 showing the best activity. This study provides a reliable experimental basis for analyzing the weathering resistance and deterioration mechanism of ancient bricks in Hubei Province, offers technical support for the restoration of local ancient buildings, and lays a foundation for the development of antique-style brick craftsmanship. Full article

The organization of safe industrial waste management is an integral part of the global sustainable development strategy. This study provides a preliminary assessment of the processing and recycling potential of strongly alkaline (pH 11–12) sediments accumulated in an abandoned sludge pond (Berezniki, Perm Krai, Russia), based on the initial characterization of their material composition. Sediment samples from the sludge pond were collected, layer-by-layer, over the entire depths of four sediment cores. The collected samples have the following characteristics: sediment particles are composed of up to 80% fine particles < 0.05 mm, with up to 20% fine particles < 0.002 mm. XRD data showed that the sediment consisted of calcite (67.7 wt.%), halite (11.5 wt.%), and other hydrogenic and terrigenous minerals. XRF data also found that the primary constituents in the sediment are CaO (up to 40%), Cl (up to 13%), and LOI (up to 35%). The results of the material composition study indicate a high degree of similarity between the accumulated sediments and solid waste from soda ash production, known as ammonia–soda residue (ASR). Based on experience with calcium-containing waste, this study recommends options for the secondary use of sludge, identifying two main possibilities: environmental protection and construction. We have developed an algorithm for the recycling and reuse of sludge that identifies risks, limitations, and recommended next steps. However, significant knowledge gaps regarding the environmental, toxicological, and the physical–mechanical properties of sludge prevent us from recommending a specific disposal option. The results of this review will serve as guidelines to help develop a roadmap for the disposal process. They will also inform decision-makers about sustainability issues related to industrial waste disposal. Full article

This article presents the results of investigations into washed mineral waste (WMW) from grit chambers, fly ash generated during the thermal treatment of municipal sewage sludge (SSA), and their mixtures prepared in varying proportions. Their general physicochemical characteristics and heavy metal concentrations were presented. An experiment was conducted to assess the mobility of metals in the analyzed samples during extraction with distilled water and groundwater. The feasibility and safety of using the recovered materials in the ground environment, as soil backfills, and as materials for the construction of roads and flood embankments, were assessed. The feasibility of safely using materials in the indicated construction solutions was demonstrated for WMW and mixtures with a dominant WMW content. These results will be helpful in further research on solid waste applications. To the best of the authors’ knowledge, this study is the first to confirm the ecological safety of the analyzed wastes, as evidenced by assessments of heavy metal content and mobility. Furthermore, taking into account the laboratory and field costs associated with waste verification to obtain appropriate values for other physical and mechanical parameters (e.g., compaction index or shear strength), and the need to determine the level of waste contamination before practical application, the physicochemical tests carried out are economically justified. Full article

To address the technical bottlenecks of strong background radiation interference and weak target signals in mid-wave infrared (MWIR) hyperspectral mineral detection over complex terrain, this paper proposes a “full-link background radiation suppression” methodological framework. A coupled illumination-terrain-atmosphere-sensor radiative transfer model is constructed to systematically quantify how multidimensional parameters—such as observation geometry, surface temperature, elevation, aerosol optical depth, and water vapor content—influence the target background radiation contrast. The findings reveal that daytime observation, lower surface temperature, higher altitude, dry atmosphere, and moderate solar and observation zenith angles are key factors for maximizing the signal-to-noise ratio. Comprehensive optimization analysis demonstrates that observations during midday in autumn and winter achieve optimal performance, with the target background relative contrast potentially enhanced by up to 6.29 times compared to unfavorable conditions such as summer nights. This work elucidates the physical mechanisms governing MWIR hyperspectral detection efficacy in complex scenarios, provides direct parameter-optimization strategies for intelligent mission planning of spaceborne imaging systems, and holds significant value for advancing mineral remote sensing from “passive acquisition” to “cognitive detection”. Full article

Steel slag is a major solid waste generated by the steelmaking industry. Its characteristics, including high hardness and large specific surface area, offer the potential to replace traditional mineral fillers in asphalt mixtures. However, the high alkalinity of unmodified steel slag often leads to unbalanced rheological properties and insufficient moisture stability in asphalt mastic. In this study, a modified steel slag filler was prepared using a process involving crushing and screening, water washing for dealkalization, and surface modification with a silane coupling agent. Using limestone powder and hydrated lime as control groups, the modification effects on base asphalt mastic were systematically investigated. Rheological properties were characterized using a dynamic shear rheometer (DSR) and bending beam rheometer (BBR). Interfacial performance was evaluated through pull-off tests and water immersion dispersion tests. Furthermore, mechanisms were elucidated using X-ray Fluorescence (XRF), BET specific surface area analysis, and surface free energy (SFE) tests. The results indicate that the modified steel slag significantly enhances the high-temperature deformation resistance of the asphalt mastic. At 58 °C, the complex modulus reached 7.3 MPa, representing increases of 43.3% compared to limestone powder mastic. At −18 °C, the creep stiffness increased by only 3.0%, suggesting that low-temperature cracking resistance remained fundamentally stable. The water immersion dispersion loss rate was 2.12%, and the attenuation rate of pull-off strength after water immersion was 12.5%, indicating that its resistance to moisture damage is superior to that of limestone powder and comparable to that of hydrated lime. Mechanism analysis reveals that the large specific surface area of the modified steel slag strengthens physical adsorption, while the basic oxides undergo a weak acid–base reaction with the acidic components of the asphalt. Additionally, surface modification improves compatibility. The preparation process for modified steel slag is simple; it can be used as a standalone substitute for traditional mineral fillers, balancing both performance and environmental benefits. Full article