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1. Universal Displacements in Anisotropic Linear Cauchy Elasticity

   https://doi.org/10.1007/s10659-024-10094-5  

   Yavari, Arash; Sfyris, Dimitris (February 2025, Journal of Elasticity)
2. Heterogeneity and nonaffinity of cell-induced matrix displacements

   https://doi.org/10.1103/PhysRevE.98.052410  

   Burkel, Brian; Proestaki, Maria; Tyznik, Stephen; Notbohm, Jacob (November 2018, Physical Review E)
3. Compressible Flow Through Flat Valve Seals at Microscale Displacements

   https://doi.org/10.1115/1.4065383  

   Hagstrom, Nathan P; Gallagher, Matthew L; Chase, Thomas R (November 2024, Journal of Fluids Engineering)

   Abstract Existing analytical flow models for predicting flow rates at microscale seal displacements are limited to two separate domains. The first assumes a small channel length to height aspect ratio at relatively large seal displacements. The second assumes a large channel length to height aspect ratio at relatively small seal displacements. A piecewise analytical model for compressible flow is developed here to enable predicting flow rates in valves with fluid pathways of any aspect ratio. The new model is validated by numerical studies and experiment. The results are applicable to flat valve seals having a cylindrical seal boss feature with fluid passage length to height aspect ratios ranging from 3.3 to 800. The new model is particularly useful for the design of microvalves and macroscale valves with small actuator displacements. 

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4. Giant Modulation of Refractive Index from Picoscale Atomic Displacements

   https://doi.org/10.1002/adma.202311559  

   Zhao, Boyang; Ren, Guodong; Mei, Hongyan; Wu, Vincent_C; Singh, Shantanu; Jung, Gwan_Yeong; Chen, Huandong; Giovine, Raynald; Niu, Shanyuan; Thind, Arashdeep_S; et al (April 2024, Advanced Materials)

   Abstract It is shown that structural disorder—in the form of anisotropic, picoscale atomic displacements—modulates the refractive index tensor and results in the giant optical anisotropy observed in BaTiS₃, a quasi‐1D hexagonal chalcogenide. Single‐crystal X‐ray diffraction studies reveal the presence of antipolar displacements of Ti atoms within adjacent TiS₆chains along thec‐axis, and threefold degenerate Ti displacements in thea–bplane.^47/49Ti solid‐state NMR provides additional evidence for those Ti displacements in the form of a three‐horned NMR lineshape resulting from a low symmetry local environment around Ti atoms. Scanning transmission electron microscopy is used to directly observe the globally disordered Tia–bplane displacements and find them to be ordered locally over a few unit cells. First‐principles calculations show that the Tia–bplane displacements selectively reduce the refractive index along theab‐plane, while having minimal impact on the refractive index along the chain direction, thus resulting in a giant enhancement in the optical anisotropy. By showing a strong connection between structural disorder with picoscale displacements and the optical response in BaTiS₃, this study opens a pathway for designing optical materials with high refractive index and functionalities such as large optical anisotropy and nonlinearity. 

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5. Universal displacements in inextensible fiber-reinforced linear elastic solids

   https://doi.org/10.1177/10812865231181924  

   Yavari, Arash (July 2023, Mathematics and Mechanics of Solids)

   For a given class of materials, universal displacements are those displacements that can be maintained for any member of the class by applying only boundary tractions. In this paper, we study universal displacements in compressible anisotropic linear elastic solids reinforced by a family of inextensible fibers. For each symmetry class and for a uniform distribution of straight fibers respecting the corresponding symmetry, we characterize the respective universal displacements. A goal of this paper is to investigate how an internal constraint affects the set of universal displacements. We have observed that other than the triclinic and cubic solids in the other five classes (a fiber-reinforced solid with straight fibers cannot be isotropic), the presence of inextensible fibers enlarges the set of universal displacements. 

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