-selectin is a key lectin essential for leukocyte capture and rolling on vessel walls. Functional adhesion of L-selectin requires a minimal threshold of hydrodynamic shear. Using high temporal resolution videomicroscopy, we now report that L-selectin engages its ligands through exceptionally labile adhesive bonds (tethers) even below this shear threshold. These tethers share a lifetime of 4 ms ...

Carbon fiber reinforced polymer (CFRP) sheets are externally bonded to reinforced concrete (RC) members to provide additional strength such as flexural, shear, etc. It has been widely accepted that carbon fiber reinforced polymers (CFRPs) can be used effectively to strengthen reinforced concrete (RC) members. This paper is intended to study and use externally bonded CFRP strips to repair and st...

Few-layer graphene has attracted tremendous attention owing to its exceptional electronic properties inherited from single-layer graphene and new features led by introducing extra freedoms such as interlayer stacking sequences or rotations. Effectively probing interlayer shear modes are critical for unravelling mechanical and electrical properties of few-layer graphene and further developing it...

The structural origins for the high plasticity of a Zr53Cu18.7Ni12Al16.3 (at.%) bulk metallic glass are explored. Under plastic flow conditions, in situ synchrotron high-energy X-ray diffraction reveals that the atomic strain saturates to the closest packing in the longitudinal direction of the applied load while atoms yield in the transverse plane. Scanning electron microscopy investigation re...

We establish the variational principle of Kolmogorov-PetrovskyPiskunov (KPP) front speeds in temporally random shear flows inside an infinite cylinder, under suitable assumptions of the shear field. A key quantity in the variational principle is the almost sure Lyapunov exponent of a heat operator with random potential. The variational principle then allows us to bound and compute the front spe...

Speed ensemble of bistable (combustion) fronts in mean zero stationary Gaussian shear flows inside two and three dimensional channels is studied with a min-max variational principle. In the small root mean square regime of shear flows, a new class of multi-scale test functions are found to yield speed asymptotics. The quadratic speed enhancement law holds with probability arbitrarily close to o...

We have observed 2D protein crystallization under conditions where in the absence of flow, crystallization fails to occur. Even under conditions where crystallization does occur in quiescent systems, we have found that flow can accelerate the crystallization process. By interrogating the flow responsible for this enhanced crystallization, we have correlated the enhancement with large shear in t...

We use a 3D computational model to study the fluid transport and mixing due to the beating of an infinite array of cilia. In accord with recent experiments, we observe two distinct regions: a fluid transport region above the cilia and a fluid mixing region below the cilia tip. The metachronal wave due to phase differences between neighboring cilia is known to enhance the fluid transport above t...

Understanding how bacteria move close to a surface under various stimuli is crucial for a broad range of microbial processes including biofilm formation, bacterial transport and migration. While prior studies focus on interactions between single stimulus and bacterial suspension, we emphasize on compounding effects of flow shear and solid surfaces on bacterial motility, especially reorientation...

High-pressure (129)Xe NMR has been used to monitor in real time the self-assembly of reverse water-in-supercritical carbon dioxide micelles in the absence of shear, without the need for sensitivity enhancement techniques such as hyperpolarization.