Bio-Mediated Technique to Control Phase Changes of Porous Media in Seasonally Frozen Ground

控制季节性冻土中多孔介质相变的生物介导技术

• 批准号: 2314099
• 负责人: Tejo Bheemasetti
• 金额: $ 45.3万
• 依托单位: University of Arizona
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-01-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2314099&HistoricalAwards=false
• 关键词: Bio; Mediated; Technique; Control; Phase

This award will develop a bio-mediated technique to reduce freezing and ice lens formation in soils using antifreeze proteins (AFPs) from psychrophilic (cold-loving) microorganisms. The moisture in the seasonally frozen ground, when subjected to freeze-thaw cycles, can develop large ice lenses that degrade the performance of civil infrastructure and affects land surface characteristics such as radiation balance and latent heat exchange. A significant amount of rehabilitation efforts, chemicals, and conservative design approaches are currently used to maintain cold-region infrastructure in serviceable conditions. Our solution is to extract AFPs from psychrophiles and use them to change the freezing characteristics of water in soil to prevent the formation of the detrimental ice lenses. The research will be complemented by establishing an educational and outreach program to engage undergraduate students in convergence research on bio-inspired solutions to complex engineering problems and incorporate cold-region bio-geotechnics in the curriculum.The goal of this project is to investigate, optimize, and develop a bio-mediated sustainable approach to control the phase change transformations of the pore-water present in the porous media of seasonally frozen ground. The growth of ice-lenses in porous soil media is a complex thermomechanical process that depends on freezing rate, heat extraction, the equilibrium of thermal, mechanical, and chemical forces, and effective stress on soil skeleton. We will investigate the following specific objectives: (1) characterize the antifreeze properties of moderate to hyperactive AFPs from different psychrophiles; (2) investigate the bio-treated soils’ thermal characteristics including thermal hysteresis, phase changes, freezing point and evaluate corresponding ice inhibition, ice shaping, and ice recrystallization activities; and (3) evaluate the resiliency of the bio-mediated technique to freeze-thaw cycles and investigate the strength and deformation characteristics of the untreated and bio-treated soils. This project will advance the knowledge base in applications of AFPs, ice mechanics, and soil-ice interfaces to enhance resiliency of cold region infrastructure.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

该奖项将开发一种生物介导的技术，以减少冻结和冰透镜的形成，在土壤中使用抗冻蛋白（AFP）从嗜冷（冷）微生物。季节性冻土中的水分在经历冻融循环时会形成大的冰透镜体，降低民用基础设施的性能，并影响辐射平衡和潜热交换等地表特征。目前正在使用大量的修复工作、化学品和保守的设计方法来维持寒冷地区基础设施的可用状态。我们的解决方案是从嗜冷菌中提取AFP，并用它们来改变土壤中水的冻结特性，以防止有害的冰透镜体的形成。该研究将通过建立一个教育和推广计划来补充，以吸引本科生参与复杂工程问题的生物启发解决方案的融合研究，并将寒区生物土工学纳入课程。该项目的目标是调查，优化，并开发一种生物介导的可持续方法来控制孔隙的相变转化，存在于季节性冻土的多孔介质中的水。冰透镜体在多孔土壤介质中的生长是一个复杂的热力学过程，取决于冻结速率、热量提取、热力、机械力和化学力的平衡以及土壤骨架上的有效应力。本论文的主要研究内容如下：（1）研究不同嗜冷菌中活性到高活性的抗冻蛋白的抗冻特性;（2）研究生物处理土壤的热特性，包括热滞、相变、冰点，并评价相应的冰抑制、冰成形和冰重结晶活性;（3）评估生物介导技术对冻融循环的恢复力，并研究未经处理和生物处理的土壤的强度和变形特性。该项目将推进AFP、冰力学和土壤-冰界面应用的知识基础，以增强寒冷地区基础设施的弹性。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。