Stable-streamlined cavities following the impact of non-superhydrophobic spheres on water

Abstract

Demonstrated is a stable-streamlined cavity attached to a hydrophilic sphere free-falling in water.

Free-Rising Bubbles Bounce More Strongly from Mobile than from Immobile Water–Air Interfaces

“…Finally, we want to once more clarify that water–air interface mobility does not depend only on the water purity and the presence of surfactants but is also a strong function of the hydrodynamic regime and related shear rates. Smaller and slow moving bubbles are much easier to immobilize − compared to larger bubbles subject to higher shear rates. − Accordingly, all results for the water–air interface mobility discussed here should be considered in the context of the present experiments, which consist of millimeter-sized free-rising bubbles colliding with water–air interfaces.…”

“…15 However, larger bubbles (of millimeter size) are shown to rise as a tangentially mobile interface if no added surfactant is present in the water. 19−22 Finally, for macroscopic bubbles and high shear rates as in foam shear experiments 23 or in the free-fall of centimeter-sized spheres with attached air cavities, 24,25 the bubble interface can be mobile even when a high concentration of low-modulus surfactants is present in the water.…”

“…Small bubbles in the submillimeter size range freely rising in the Stokes flow regime are extremely sensitive to the presence of minute amounts of contaminates and will be immobilized at surfactant concentrations which are too low to be detected by the change in the water–air interfacial tension. − A recent work has also hypothesized that mobile surface charge adsorption at the water interface can also contribute to the immobilization of the water–air interface . However, larger bubbles (of millimeter size) are shown to rise as a tangentially mobile interface if no added surfactant is present in the water. − Finally, for macroscopic bubbles and high shear rates as in foam shear experiments or in the free-fall of centimeter-sized spheres with attached air cavities, , the bubble interface can be mobile even when a high concentration of low-modulus surfactants is present in the water.…”

Bioinspired Universal Approaches for Cavity Regulation during Cylinder Impact Processes for Drag Reduction in Aqueous Media: Macrogeometry Vanquishing Wettability

“…The other type is the passive method to retain the gas layer by a superhydrophobic coating. The immersed superhydrophobic surface can inherently stabilize the underwater gas film by entrapping gas pockets among the micro–nanostructure to form a “Cassie” state. − However, the gas pockets are gradually disrupted by the surrounding shear flow, leading to an unwanted drag increase. − Moreover, the micro–nanostructure on the superhydrophobic coating is fragile, and the coating-based method is currently limited due to its high cost, easy corrosion, and sensitive to abrasive conditions. − Consequently, a feasible, robust, and universal strategy to stabilize the underwater gas–liquid interface without an external energy input remains extremely challenging.…”

CXCL1 Regulated by miR-302e Is Involved in Cell Viability and Motility of Colorectal Cancer via Inhibiting JAK-STAT Signaling Pathway

“…As research goes on, CXCL1 has been identified to be intimately associated with the development of various cancers. For instance, Chengcheng Yang et al (16) found that CXCL1 could induce activation of ERK/MMP2/9 signaling axis to stimulate cell migration and invasion of ER-negative breast cancer. Lu Y et al (17) indicated that CXCL1-LCN2 axis is able to positively function on the development of prostate cancer via boosting Src signaling pathway activation as well as epithelial-mesenchymal transition process.…”