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1. Numerical Simulation of Plasma Interfaces Using the Starfish Plasma Simulation Code

   https://doi.org/10.2514/6.2020-3245  

   Senig, James; Wang, Xiaowen (June 2020, AiAA Aviation Forum 2020)

   null (Ed.)

   A particular challenge for low temperature plasma (LTP) research is the diversity of parameter space and conditions. For plasma systems where the densities are not low, the kinetic theory is time-consuming and becomes unrealistic. In this regime, the particle-in-Cell (PIC) method is appropriate where the evolution of a particle system at every time step consists of an Eulerian stage and a Lagrangian stage. The PIC method can deal with complex geometries and large distortions in the field. The PIC solver, Starfish, is a two-dimensional plasma and gas simulation code operating on structured 2D/axisymmetric Cartesian or body fitted stretched meshes. The purpose of this study is to use the Starfish Plasma Simulation Code for numerical simulations of plasma interfaces. Specifically, two applications are considered: 1) the modeling of a large area (30 cm x 30 cm) microwave plasma chemical vapor deposition system, and 2) the understanding of LTP treatment on surface modification of polycaprolactone pellets and thermal properties of extruded filaments. With the exact geometries and experimental results being provided, numerical simulations of these two applications are ongoing. 

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2. LEAP-2017 Simulation Exercise: Calibration of Constitutive Models and Simulation of the Element Tests

   https://doi.org/10.1007/978-3-030-22818-7_9  

   Manzari, M.T. (November 2019, Proceedings of LEAP-UCD-2017 workshop)

   This paper presents a summary of the element test simulations (calibration simulations) submitted by 11 numerical simulation (prediction) teams that participated in the LEAP-2017 prediction exercise. A significant number of monotonic and cyclic triaxial (Vasko, An investigation into the behavior of Ottawa sand through monotonic and cyclic shear tests. Masters Thesis, The George Washington University, 2015; Vasko et al., LEAP-GWU-2015 Laboratory Tests. DesignSafe-CI, Dataset, 2018; El Ghoraiby et al., LEAP 2017: Soil characterization and element tests for Ottawa F65 sand. The George Washington University, Washington, DC, 2017; El Ghoraiby et al., LEAP-2017 GWU Laboratory Tests. DesignSafe-CI, Dataset, 2018; El Ghoraiby et al., Physical and mechanical properties of Ottawa F65 Sand. In B. Kutter et al. (Eds.), Model tests and numerical simulations of liquefaction and lateral spreading: LEAP-UCD-2017. New York: Springer, 2019) and direct simple shear tests (Bastidas, Ottawa F-65 Sand Characterization. PhD Dissertation, University of California, Davis, 2016) are available for Ottawa F-65 sand. The focus of this element test simulation exercise is to assess the performance of the constitutive models used by participating team in simulating the results of undrained stress-controlled cyclic triaxial tests on Ottawa F-65 sand for three different void ratios (El Ghoraiby et al., LEAP 2017: Soil characterization and element tests for Ottawa F65 sand. The George Washington University, Washington, DC, 2017; El Ghoraiby et al., LEAP-2017 GWU Laboratory Tests. DesignSafe-CI, Dataset, 2018; El Ghoraiby et al., Physical and mechanical properties of Ottawa F65 Sand. In B. Kutter et al. (Eds.), Model tests and numerical simulations of liquefaction and lateral spreading: LEAP-UCD-2017. New York: Springer, 2019). The simulated stress paths, stress-strain responses, and liquefaction strength curves show that majority of the models used in this exercise are able to provide a reasonably good match to liquefaction strength curves for the highest void ratio (0.585) but the differences between the simulations and experiments become larger for the lower void ratios (0.542 and 0.515). 

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3. Quantum simulation of Unruh radiation

   https://doi.org/10.1038/s41567-019-0537-1  

   Hu, Jiazhong; Feng, Lei; Zhang, Zhendong; Chin, Cheng (May 2019, Nature Physics)
4. Differentiable Simulation of Inertial Musculotendons

   https://doi.org/10.1145/3550454.3555490  

   Wang, Ying; Verheul, Jasper; Yeo, Sang-Hoon; Kalantari, Nima Khademi; Sueda, Shinjiro (December 2022, ACM Transactions on Graphics)

   We propose a simple and practical approach for incorporating the effects of muscle inertia, which has been ignored by previous musculoskeletal simulators in both graphics and biomechanics. We approximate the inertia of the muscle by assuming that muscle mass is distributed along the centerline of the muscle. We express the motion of the musculotendons in terms of the motion of the skeletal joints using a chain of Jacobians, so that at the top level, only the reduced degrees of freedom of the skeleton are used to completely drive both bones and musculotendons. Our approach can handle all commonly used musculotendon path types, including those with multiple path points and wrapping surfaces. For muscle paths involving wrapping surfaces, we use neural networks to model the Jacobians, trained using existing wrapping surface libraries, which allows us to effectively handle the Jacobian discontinuities that occur when musculotendon paths collide with wrapping surfaces. We demonstrate support for higher-order time integrators, complex joints, inverse dynamics, Hill-type muscle models, and differentiability. In the limit, as the muscle mass is reduced to zero, our approach gracefully degrades to traditional simulators without support for muscle inertia. Finally, it is possible to mix and match inertial and non-inertial musculotendons, depending on the application. 

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5. Quantum simulation of conical intersections

   https://doi.org/10.1039/d4cp00391h  

   Wang, Yuchen; Mazziotti, David A (April 2024, Physical Chemistry Chemical Physics)

   We explore the simulation of conical intersections (CIs) on quantum devices, setting the groundwork for potential applications in nonadiabatic quantum dynamics within molecular systems. 

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