Carbon capture, utilization, and storage (CCUS) in coal seam is critical for achieving carbon neutrality, yet the risk of CO2 leakage remains a major challenge. Denitrification-induced carbonate precipitation (DICP) mediated by indigenous microorganisms offers a promising strategy to limit CO2 migration in coal seam. This study investigated how organics derived from coal biodegradation (OCB) contribute to bio-carbonate formation via DICP. Results indicated that large amount of low-molecular weight OCB were progressively generated. The concentration of chemical oxygen demand (COD) ranged from 1314 mg/L to 1165.5 mg/L with the dominance of acids, especially aliphatic acids, which were mainly generated from oxygen-containing functional groups in coal. Using OCB as the sole carbon source, a mineralization efficiency of 71.3% was achieved, with propionic and 2-methyl-butanoic acids being consumed by 76.71% and 30.71%, respectively. When coal-degrading microorganisms and DICP microflora coexisted, the mineralization efficiency increased to 80.42%. The continuous generation of OCB during DICP stimulated bacterial growth, promoted denitrification process and extracellular polymeric substance (EPS) production, leading to > 80% calcite formed. The precipitated minerals filled the pores in coal, resulting in a reduction of macropore and mesopore volumes by 38.36% and 91.84%, respectively, suggesting OCB could strongly support DICP to reduce the pore development of coal. These findings demonstrated the benefit of organics in coal to prevent CO2 leakage by supporting DICP, providing a cost-effective and environmentally synergistic approach for CCUS within coal seam.
Abstract Preventive pavement maintenance treatments remain essential in prolonging the lifespan and ride quality of pavements, but their performance could vary depending on the environmental and climatic conditions. The purpose of this study is to evaluate both the short- and the long-term performance effectiveness of slurry seal, chip seal, crack seal, and asphalt thin overlay in the wet freeze and the dry freeze regions of the United States and Canada using the long-term pavement performance program (LTPP) database. Performance jump and weighted distress were used as measures of effectiveness for longitudinal cracking (nonwheel path), transverse cracking, fatigue cracking, rutting, and International Roughness Index. A generalized least square regression and post hoc Dunnett’s test were used for the statistical analysis. The results show that climate (dry freeze and wet freeze) significantly influenced the short-term performance of treatments regarding longitudinal cracking and transverse cracking, but this factor did not significantly impact the long-term performance of any of the treatments. Asphalt thin overlay was the most effective for both the short- and long-term treatment of all the pavement distresses under study. Aside asphalt thin overlay, slurry seal and chip seal were effective for treating short-term fatigue cracking and longitudinal cracking. Chip seal was only effective in the long-term treatment of longitudinal cracking and fatigue cracking. Higher pretreatment roughness significantly increased the chances of posttreatment pavement roughness and transverse cracking. Higher truck traffic loading also led to higher rutting in pavements. The results here provide insights to pavement maintenance professionals in the industry on the selection of the most appropriate treatments for pavement sections in these freeze regions.
The development of flexible and wearable energy storage systems demands zinc-ion batteries with high capacity, mechanical robustness, and long-term electrochemical stability. Vanadium oxide (V6O13.nH(2)O), with its high theoretical capacity, is a promising cathode material for aqueous and flexible Zn-ion batteries. However, its practical application is hindered by structural instability, vanadium dissolution, and sluggish Zn2+ reaction kinetics, mainly under mechanical deformation. To address these challenges, nanoscale engineering has emerged as an effective strategy to improve both electrochemical performance and mechanical stability. Herein, monoclinic-phase V6O13.nH(2)O nanobelts are synthesized as robust cathodes, enabling ultrafast Zn2+ kinetics, a medium operating temperature range, and excellent structural stability suitable for flexible battery configurations. The experimental results demonstrated an outstanding electrochemical performance of the V6O13.nH(2)O nanobelts cathode, delivering a high specific capacity of 400 mAh g(-1) at 0.1 A g(-1) and retaining similar to 95% capacity after 500 cycles at 1 A g(-1) at different temperatures. Furthermore, the coin cell configuration maintains 79% capacity after 1500 cycles, whereas the flexible battery exhibits 78% capacity retention after 600 cycles at 10 A g(-1). This work highlights vanadium-based cathode design in overcoming limitations of flexible Zn-ion batteries and provides valuable insights into the electrochemical mechanisms governing high-performance electrodes.
Below-canopy downwelling shortwave radiation (SWR) influences snow ablation, soil microclimate, and carbon uptake, yet remains difficult to map in heterogeneous forests. To address this, we measured below-canopy SWR using a 122-m cable-borne mobile tram equipped with an upward-facing pyranometer along a transect spanning a subalpine forest-to-fen ecotone. Subsequently, airborne lidar-derived forest structure was used in a Lidar-to-Radiation canopy ray tracing model to simulate spatial patterns of SWR at 30-min timesteps across the full growing season (21 Mar. - 21 Sep. 2023). Simulated SWR demonstrated strong agreement with field measurements (Spearman ρ = 0.95). At 1-m horizontal resolution, the model captured tree- and gap-scale variability and growing-season contrasts. When applied to two neighboring 1 ha forest plots, simulated SWR had a monotonic, log-linear relation with sky-view factor (SVF) (R2 = 0.96 and 0.78). SVF adequately explained the mean tendency but not the fine-scale or temporal variation of SWR. Within a single SVF class (±5% SVF interval), growing-season SWR spanned wide ranges (e.g., 46-166 W m-2 at 10% SVF and 311-398 W m-2 at 50% SVF), suggesting additional geometric controls such as relative crown position, height, and shape that were not captured by SVF. Thus, ecohydrological extremes—early snow disappearance, soil moisture deficits, or persistent shade—can coexist within a narrow SVF range. Results demonstrate the ability of a three-dimensional ray tracing model to capture sunflecks, canopy edge shadows, and terrain masking in a subalpine forest. Model errors likely reflect sensitivity to woody element representation, meter-scale uncertainty in lidar geolocation and sensor positioning, and model parameters. Coupled observation and model systems provide a transferable method to scale results from meteorological stations to transects and landscapes. Integrating such detailed measurements with process-based modeling is essential for understanding how canopy structure shapes energy availability, soil moisture and plant water availability, and land-atmosphere interactions.
Chemical herbicides, including glyphosate, atrazine, and many others, are commonly used to control unwanted vegetation in agroecosystems and protect crop yield potential. While the effects of herbicides on aboveground weedy vegetation are well documented, by comparison, the influence of herbicides on belowground processes is poorly understood. Given the importance of the soil microbiome for providing ecosystem services, understanding microbial responses to herbicide application is of pressing interest. In this study, the short-term non-target effects of herbicide application were examined by comparing three commonly used chemical herbicides, glyphosate, dicamba, and a tank mixture of atrazine + mesotrione, to handweeded and non-treated controls. Changes in soil microbial function, nutrient pools, and microbiome composition in Zea mays were assayed over 20 days post-treatment. Direct effects of the examined herbicides on soil edaphic properties, microbial alpha-diversity, and enzyme activities were small and transient over this 20-day, short-term experiment. Changes in enzymatic activities, nutrient concentrations, and fungal community structure were predicted primarily by weedy vegetation cover, suggesting that the observed responses are indirectly mediated by herbicide application. Conversely, weed removal treatment was a significant predictor of bacterial community composition, and chemical herbicide application was associated with homogenization of the bacterial community over the short sampling period, a trend not observed in the non-treated and handweeded controls. Together, these results indicate that in heavily managed agroecosystems, the short-term direct effects of chemical herbicide application on microbial diversity and enzymatic function are modest, whereas the effects on bacterial community assembly, composition, and heterogeneity are more readily detectable. The observed trend of biotic homogenization following pesticide application, a pattern not observed in the handweeded and non-treated controls, warrants further examination over longer time scales and repeated herbicide applications.
