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1. Predicting freeze-thaw deterioration in wood-polymer composites

   https://doi.org/10.26168/icbbm2017.79  

   Hess, K. M. (June 2017, Academic journal of civil engireering)

   Natural fiber-reinforced polymers are currently used in a variety of low- to high-performance applications in the automotive, packaging, and construction industries. Previous studies have demonstrated that natural fibers (e.g., flax, hemp) exhibit good tensile mechanical properties and have positive environmental and economic attributes such as low cost, rapid renewability, and worldwide availability. However, natural fibers are inherently susceptible moisture-induced changes in physical and mechanical properties, which can be unfavorable for in-service use. This study illustrates how a micromechanics-based modelling approach can be used to help facilitate durability design and mitigate the deleterious effects of freeze-thaw deterioration in wood-plastic composites (WPCs). The model described in this study predicts the critical fiber volume fraction (V_fcrit) at which damage to the composite will occur under certain environmental conditions for different WPC formulations of hardwood and softwood fiber reinforcement and polymer matrix types. As expected, the results show that V_fcrit increases (a positive result) as anticipated in situ moisture content decreases. In addition, results suggest that fiber packing distribution directly influences V_fcrit and that V_fcrit increases as the mechanical properties of the polymer matrix increase. In sum, the study demonstrates how predictive modeling can be applied during the design phase to ensure the durability of WPCs. 

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2. Soil microbial legacies influence freeze–thaw responses of soil

   https://doi.org/10.1111/1365-2435.14273  

   Pastore, Melissa A; Classen, Aimée T; English, Marie E; Frey, Serita D; Knorr, Melissa A; Rand, Karin; Adair, E Carol (April 2023, Functional Ecology)

   Abstract Warmer winters with less snowfall are increasing the frequency of soil freeze–thaw cycles across temperate regions. Soil microbial responses to freeze–thaw cycles vary and some of this variation may be explained by microbial conditioning to prior winter conditions, yet such linkages remain largely unexplored. We investigated how differences in temperature history influenced microbial community composition and activity in response to freeze–thaw cycles.We collected soil microbial communities that developed under colder (high elevation) and warmer (low elevation) temperature regimes in spruce‐fir forests, then added each of these soil microbial communities to a sterile bulk‐soil in a laboratory microcosm experiment. The inoculated high‐elevation cold and low‐elevation warm microcosms were subjected to diurnal freeze–thaw cycles or constant above‐freezing temperature for 9 days. Then, all microcosms were subjected to a 7‐day above‐freezing recovery period.Overall, we found that the high‐elevation cold community had, relative to the low‐elevation warm community, a smaller reduction in microbial respiration (CO₂flux) during freeze–thaw cycles. Further, the high‐elevation cold community, on average, experienced lower freeze–thaw‐induced bacterial mortality than the warm community and may have partly acclimated to freeze–thaw cycles via increased lipid membrane fluidity. Respiration of both microbial communities quickly recovered following the end of the freeze–thaw treatment period and there were no changes in soil extractable carbon or nitrogen.Our results provide evidence that past soil temperature conditions may influence the responses of soil microbial communities to freeze–thaw cycles. The microbial community that developed under a colder temperature regime was more tolerant of freeze–thaw cycles than the community that developed under a warmer temperature regime, although both communities displayed some level of resilience. Taken together, our data suggest that microbial communities conditioned to less extreme winter soil temperatures may be most vulnerable to rapid changes in freeze–thaw regimes as winters warm, but they also may be able to quickly recover if mortality is low. Read the freePlain Language Summaryfor this article on the Journal blog. 

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3. Nitrate loading projection is sensitive to freeze-thaw cycle representation

   https://doi.org/10.1016/j.watres.2020.116355  

   Wang, Qianfeng; Qi, Junyu; Li, Jia; Cole, Jefferson; Waldhoff, Stephanie T.; Zhang, Xuesong (November 2020, Water Research)

   null (Ed.)
4. Effect of Salt Concentrations on the Freeze–Thaw Behavior of Soils

   https://doi.org/10.1061/9780784485460.022  

   Naqvi, Mohammad Wasif; Sadiq, Md Fyaz; Cetin, Bora; Uduebor, Micheal; Daniels, John (May 2024, American Society of Civil Engineers)
5. Validation of the SMAP freeze/thaw product using categorical triple collocation

   https://doi.org/10.1016/j.rse.2017.12.007  

   Lyu, Haobo; McColl, Kaighin A.; Li, Xinlu; Derksen, Chris; Berg, Aaron; Black, T. Andrew; Euskirchen, Eugenie; Loranty, Michael; Pulliainen, Jouni; Rautiainen, Kimmo; et al (February 2018, Remote Sensing of Environment)