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1. Asymmetry of thermal sensitivity and the thermal risk of climate change

   https://doi.org/10.1111/geb.13570  

   Buckley, Lauren B.; Huey, Raymond B.; Kingsolver, Joel G. (July 2022, Global Ecology and Biogeography)

   Abstract AimUnderstanding and predicting the biological consequences of climate change requires considering the thermal sensitivity of organisms relative to environmental temperatures. One common approach involves ‘thermal safety margins’ (TSMs), which are generally estimated as the temperature differential between the highest temperature an organism can tolerate (critical thermal maximum, CT_max) and the mean or maximum environmental temperature it experiences. Yet, organisms face thermal stress and performance loss at body temperatures below their CT_max,and the steepness of that loss increases with the asymmetry of the thermal performance curve (TPC). LocationGlobal. Time period2015–2019. Major taxa studiedAnts, fish, insects, lizards and phytoplankton. MethodsWe examine variability in TPC asymmetry and the implications for thermal stress for 384 populations from 289 species across taxa and for metrics including ant and lizard locomotion, fish growth, and insect and phytoplankton fitness. ResultsWe find that the thermal optimum (T_opt, beyond which performance declines) is more labile than CT_max, inducing interspecific variation in asymmetry. Importantly, the degree of TPC asymmetry increases with T_opt. Thus, even though populations with higher T_opts in a hot environment might experience above‐optimal body temperatures less often than do populations with lower T_opts, they nonetheless experience steeper declines in performance at high body temperatures. Estimates of the annual cumulative decline in performance for temperatures above T_optsuggest that TPC asymmetry alters the onset, rate and severity of performance decrement at high body temperatures. Main conclusionsSpecies with the same TSMs can experience different thermal risk due to differences in TPC asymmetry. Metrics that incorporate additional aspects of TPC shape better capture the thermal risk of climate change than do TSMs. 

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2. The thermal ecology of flowers

   https://doi.org/10.1093/aob/mcz073  

   van der Kooi, Casper J; Kevan, Peter G; Koski, Matthew H (June 2019, Annals of Botany)

   Abstract Background Obtaining an optimal flower temperature can be crucial for plant reproduction because temperature mediates flower growth and development, pollen and ovule viability, and influences pollinator visitation. The thermal ecology of flowers is an exciting, yet understudied field of plant biology. Scope This review focuses on several attributes that modify exogenous heat absorption and retention in flowers. We discuss how flower shape, orientation, heliotropic movements, pubescence, coloration, opening–closing movements and endogenous heating contribute to the thermal balance of flowers. Whenever the data are available, we provide quantitative estimates of how these floral attributes contribute to heating of the flower, and ultimately plant fitness. Outlook Future research should establish form–function relationships between floral phenotypes and temperature, determine the fitness effects of the floral microclimate, and identify broad ecological correlates with heat capture mechanisms. 

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3. Thermal structure of the blue whirl

   https://doi.org/10.1016/j.proci.2018.05.115  

   Hariharan, Sriram Bharath; Sluder, Evan T.; Gollner, Michael J.; Oran, Elaine S. (January 2019, Proceedings of the Combustion Institute)
4. The changing thermal state of permafrost

   https://doi.org/10.1038/s43017-021-00240-1  

   Smith, Sharon L.; O’Neill, H. Brendan; Isaksen, Ketil; Noetzli, Jeannette; Romanovsky, Vladimir E. (January 2022, Nature Reviews Earth & Environment)
5. Thermal mapping of Hollow Cathodes to model the thermal loads of Iodine Ion Propulsion

   Winner, P; Branam, R; Boehm, K (November 2019, 72nd Annual Meeting of the APS Division of Fluid Dynamics)

   null (Ed.)

   Iodine possesses desirable qualities that could make it a potential fuel of choice in future space missions requiring ion propulsion, potentially replacing Xenon; if the thruster can have similar endurance despite Iodine's corrosiveness. A computer-aided design model of a hollow cathode with a Lanthanum Hexaboride insert was created in Solidworks, using its thermal load simulator to generate an approximate temperature model of it in operation. Data was then collected to refine the model by getting temperature readings of a hollow cathode in operation by attaching type K thermocouples to the outside and inside of the hollow cathode and firing it in a vacuum chamber. Differences between the thermal model and the experimental data will be discussed in addition to the assumptions made within the thermal model. Based on the data, the hollow cathode is far below expected temperatures, though there are several sources of error to explain this discrepancy. 

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