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: 2125851
• 负责人: Tejo Bheemasetti
• 金额: $ 45.3万
• 依托单位: South Dakota School of Mines and Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2021
• 资助国家: 美国
• 起止时间: 2021-09-01 至 2023-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2125851&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技术，利用来自嗜冷微生物的抗冻蛋白（AFPs）减少土壤中的冻结和冰透镜形成。季节性冻土中的水分在经受冻融循环时，会形成巨大的冰透镜，从而降低民用基础设施的性能，并影响地表特征，如辐射平衡和潜热交换。目前，大量的修复工作、化学品和保守的设计方法被用于维持寒冷地区基础设施的可用性。我们的解决方案是从嗜冷植物中提取afp，并利用它们来改变土壤中水的冻结特性，以防止形成有害的冰透镜。这项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，并将寒区生物岩土技术纳入课程。该项目的目标是研究、优化和开发一种生物介导的可持续方法，以控制季节性冻土多孔介质中孔隙水的相变。多孔土介质中冰透镜的生长是一个复杂的热力学过程，它取决于冻结速率、热量提取、热、机械和化学力的平衡以及土壤骨架上的有效应力。我们将研究以下具体目标：(1)表征来自不同嗜冷菌的中度至过度活跃afp的抗冻特性；(2)研究生物处理土壤的热特性，包括热滞后、相变、冰点，并评估相应的冰抑制、冰成形和冰再结晶活性；(3)评估生物介导技术对冻融循环的弹性，研究未处理和生物处理土壤的强度和变形特征。该项目将推进AFPs、冰力学和土-冰界面应用方面的知识基础，以增强寒冷地区基础设施的弹性。该奖项反映了美国国家科学基金会的法定使命，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。