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1. Maximum Flow and Minimum-Cost Flow in Almost-Linear Time

   https://doi.org/10.1109/FOCS54457.2022.00064  

   Chen, Li; Kyng, Rasmus; Liu, Yang P.; Peng, Richard; Gutenberg, Maximilian Probst; Sachdeva, Sushant (October 2022, 2022 IEEE 63rd Annual Symposium on Foundations of Computer Science (FOCS))

   We give an algorithm that computes exact maximum flows and minimum-cost flows on directed graphs with m edges and polynomially bounded integral demands, costs, and capacities in m^{1+o(1)} time. Our algorithm builds the flow through a sequence of m^{1+o(1)} approximate undirected minimum-ratio cycles, each of which is computed and processed in amortized m^{o(1)} time using a new dynamic graph data structure. Our framework extends to algorithms running in m^{1+o(1)} time for computing flows that minimize general edge-separable convex functions to high accuracy. This gives almost-linear time algorithms for several problems including entropy-regularized optimal transport, matrix scaling, p-norm flows, and p-norm isotonic regression on arbitrary directed acyclic graphs. 

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2. Using magma flow indicators to infer flow dynamics in sills

   https://doi.org/10.1016/j.jsg.2017.02.005  

   Hoyer, Lauren; Watkeys, Michael K. (March 2017, Journal of Structural Geology)
3. Information Flow in Computational Systems

   https://doi.org/10.1109/TIT.2020.2987806  

   Venkatesh, Praveen; Dutta, Sanghamitra; Grover, Pulkit (July 2020, IEEE Transactions on Information Theory)
4. Flow battery electroanalysis 3: online kinetics measurements using ultramicroelectrodes in channel flow

   https://doi.org/10.1039/d2ta02132c  

   Segel, Becca; Parr, Zachary; Sawant, Tejal V.; Yim, Carissa S.; Miller, Dean M.; Henry, Thomas J.; McKone, James R. (July 2022, Journal of Materials Chemistry A)

   Redox flow batteries are attractive for grid-scale energy storage, but ongoing work on materials discovery is hampered by the difficulty of measuring electron-transfer rates under battery-relevant conditions. We have developed an experimental approach for collecting continuous voltammetric measurements of flow battery electrolytes by placing a 3-electrode cell containing an ultramicroelectrode into the flow loop of a functioning redox flow battery. We further developed an empirical approach for extracting electron-transfer rate constants from each voltammetric cycle, thereby enabling continuous measurements as a function of state of charge and cycle time. Benchmarking these approaches with iron-based aqueous flow battery electrolytes using platinum and carbon fiber ultramicroelectrodes yielded rate constants that varied in the order Pt > electrochemically oxidized carbon > pristine carbon, in good agreement with prior work. We also found that Pt electrodes become more catalytically active upon cycling for several hours, whereas carbon fiber electrodes with and without oxidative pretreatments remained stable over the same interval. We expect these experimental approaches can be used to measure kinetics and other figures of merit for most electrodes and electrolytes of interest for redox flow batteries as well as in other systems where it is useful to evaluate the properties of a flowing electrolyte in real time. 

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5. Flow modulation by a few fixed spherical particles in a turbulent channel flow

   https://doi.org/10.1017/jfm.2019.933  

   Peng, Cheng; Ayala, Orlando M.; Wang, Lian-Ping (February 2020, Journal of Fluid Mechanics)

   Current understanding of turbulence modulation by solid particles is incomplete as making reliable predictions on the nature and level of modulation remains a challenging task. Multiple modulation mechanisms may be simultaneously induced by particles, but the lack of reliable methods to identify these mechanisms and quantify their effects hinders a complete understanding of turbulence modulation. In this work, we present a full analysis of the turbulent kinetic energy (TKE) equation for a turbulent channel flow laden with a few fixed particles near the channel walls, in order to investigate how the wall generated turbulence interacts with the particles and how, as a result, the global turbulence statistics are modified. All terms in the budget equations of total and component-wise TKEs are explicitly computed using the data from direct numerical simulations. Particles are found to modify turbulence by two competing mechanisms: the reduction of the intrinsic turbulence production associated with a reduced mean shear due to the resistance imposed by solid particles (the first mechanism), and an additional TKE production mechanism by displacing incoming fluid (the second mechanism). The distribution of TKE in the wall-normal direction is also made more homogeneous due to the significantly enhanced pressure transport of TKE. Finally, the budget analysis of component-wise TKE reveals an enhanced inter-component TKE transfer due to the presence of particles, which leads to a more isotropic distribution of TKE among three velocity components. 

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