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Wildfires significantly impact hydrology and geomorphology by altering soil properties, which depend on the fire intensity, duration, and frequency. Soil organic matter (SOM) is vital for forest ecosystems, acting as fuel. In this study, unburnt and burnt soils were collected from nearby locations for a prescribed fire site. Additional samples were tested where unburnt soil was mixed with 25% volume of mulch and exposed to a temperature of 150°C and 650°C in a furnace to simulate the exposure to soil with organic matter to high temperatures experienced during wildfires. The variation of soil-water characteristic curves (SWCCs) for these different soil samples was evaluated to assess the impact of exposure to high temperature during wildfires. Results showed that low-intensity fires did not alter soil properties, while high-intensity fires resulted in a change in the soil property in terms of SWCC and physical and hydraulic characteristics, and posed greater erosion risks and disrupt soil stability, highlighting the need for better soil management strategies. 

Advancements in engineering construction have led to an increase in significant challenges with foundations and pavement infrastructure built on silty soil. Silty soils are created through the combination of mainly silt-sized particles (< 0.075 mm), typically with a small percentage of clay, and are vulnerable to frost. Biopolymers can possibly be an alternate solution for calcium-based stabilizers or be used as a co-additive. This study aimed to investigate the interaction of biopolymer-induced soil with multivalent ions via unconfined compressive strength to identify a potential stabilizer and appropriate dosages. For comparative analysis, biopolymers with different cations on silty soil strength were evaluated after curing for 7 days and 28 days. The results indicated that the biopolymer networks develop slowly; however, cross-linking the biopolymers with different cations enhanced their rate of stiffness and strength increase. This composite sample indicated a possible solution for partially replacing calcium-based stabilizers in frost-susceptible silty soil. 

Shallow borehole thermal energy storage systems provide a reliable energy source that has been anticipated to supplement the energy grid in times of energy crisis and supply power to residences and commercial entities independently. However, the efficiency of such systems is reduced with desaturation, and the construction of deeper geothermal boreholes is often quite expensive in arid and semi-arid regions with deeper groundwater tables. This paper investigates the effect of biocementation on the thermal conductivity of fine sand for different saturation levels that can increase the efficiency of the system. The variation of thermal conductivity of soils was studied before and after treatment with dental biofilm that consists of Streptococcus mutans, sp. with suction varied from saturated state to nearly dry state. It was observed that biocementation enhanced the thermal conductivity of soils for all saturation levels, with the most prominent increase being near the optimum moisture content of the fine sand. This can be utilized in shallow borehole thermal energy storage systems to improve efficiency and reduce costs. 

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