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1. Stationary Expansion Shocks for a Regularized Boussinesq System: Stationary Expansion Shocks for a Regularized Boussinesq System

   https://doi.org/10.1111/sapm.12191  

   El, Gennady A. ; Hoefer, Mark A. ; Shearer, Michael ( January 2018 , Studies in Applied Mathematics)
2. Electron Injection via Modified Diffusive Shock Acceleration in High-Mach-number Collisionless Shocks

   https://doi.org/10.3847/2041-8213/ad0cf9  

   Grassi, A. ; Rinderknecht, H. G. ; Swadling, G. F. ; Higginson, D. P. ; Park, H.-S. ; Spitkovsky, A. ; Fiuza, F. ( November 2023 , The Astrophysical Journal Letters)

   The ability of collisionless shocks to efficiently accelerate nonthermal electrons via diffusive shock acceleration (DSA) is thought to require an injection mechanism capable of preaccelerating electrons to high enough energy where they can start crossing the shock front potential. We propose, and show via fully kinetic plasma simulations, that in high-Mach-number shocks electrons can be effectively injected by scattering in kinetic-scale magnetic turbulence produced near the shock transition by the ion Weibel, or current filamentation, instability. We describe this process as a modified DSA mechanism where initially thermal electrons experience the flow velocity gradient in the shock transition and are accelerated via a first-order Fermi process as they scatter back and forth. The electron energization rate, diffusion coefficient, and acceleration time obtained in the model are consistent with particle-in-cell simulations and with the results of recent laboratory experiments where nonthermal electron acceleration was observed. This injection model represents a natural extension of DSA and could account for electron injection in high-Mach-number astrophysical shocks, such as those associated with young supernova remnants and accretion shocks in galaxy clusters.

    

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3. Density shocks in the relativistic expansion of highly charged one component plasmas

   https://doi.org/10.1103/PhysRevAccelBeams.22.114402  

   Zerbe, B. S. ; Duxbury, P. M. ( November 2019 , Physical Review Accelerators and Beams)
4. Coherent Electromagnetic Emission from Relativistic Magnetized Shocks

   https://doi.org/10.1103/PhysRevLett.127.035101  

   Sironi, Lorenzo ; Plotnikov, Illya ; Nättilä, Joonas ; Beloborodov, Andrei M. ( July 2021 , Physical Review Letters)

   null (Ed.)
5. Labor markets: A critical link between global-local shocks and their impact on agriculture

   https://doi.org/10.1088/1748-9326/acb1c9  

   Ray, Srabashi ; Haqiqi, Iman ; Hill, Alexandra E ; Taylor, J Edward ; Hertel, Thomas W ( March 2023 , Environmental Research Letters)

   Labor markets can shape the impacts of global market developments and local sustainability policies on agricultural outcomes, including changes in production and land use. Yet local labor market outcomes, including agricultural employment, migration and wages, are often overlooked in integrated assessment models (IAMs). The relevance of labor markets has become more important in recent decades, with evidence of diminished labor mobility in the United States (US) and other developed countries. We use the SIMPLE-G (Simplified International Model of agricultural Prices, Land use, and the Environment) modeling framework to investigate the impacts of a global commodity price shock and a local sustainable groundwater use policy in the US. SIMPLE-G is a multi-scale framework designed to allow for integration of economic and biophysical determinants of sustainability, using fine-scale geospatial data and parameters. We use this framework to compare the impacts of the two sets of shocks under two contrasting assumptions: perfect mobility of agricultural labor, as generally implicit in global IAMs, and relatively inelastic labor mobility (‘sticky’ agricultural labor supply response). We supplement the numerical simulations with analytical results from a stylized two-input model to provide further insights into the impacts of local and global shocks on agricultural labor, crop production and resource use. Findings illustrate the key role that labor mobility plays in shaping both local and global agricultural and environmental outcomes. In the perfect labor mobility scenario, the impact of a commodity price boom on crop production, employment and land-use is overestimated compared with the restricted labor mobility case. In the case of the groundwater sustainability policy, the perfect labor mobility scenario overestimates the reduction in crop production and employment in directly targeted grids as well as spillover effects that increase employment in other grids. For both shocks, impacts on agricultural wages are completely overlooked if we ignore rigidities in agricultural labor markets.

    

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