We revisit the classical problem of the buckling of a long thin axially compressed cylindrical shell. By examining the energy landscape of the perfect cylinder, we deduce an estimate of the sensitivity of the shell to imperfections. Key to obtaining this estimate is the existence of a mountain pass point for the system. We prove the existence on bounded domains of such solutions for almost all ...

Drag reduction is an ever-present challenge within the aeronautical engineering industry. This paper presents two substantial wing modifications: addition of a winglet freighter aircraft and dimpled on NACA 0017 aerofoils. Studies nine (9) different geometries aerofoils were performed against control model aerofoil without any dimple. Computational fluid dynamics (CFD) analysis was using (2) co...

The properties of ripplonic polarons in a multielectron bubble in liquid helium are investigated on the basis of a path-integral variational method. We find that the two-dimensional electron gas can form deep dimples in the helium surface, or ripplopolarons, to solidify as a Wigner crystal. We derive the experimental conditions of temperature, pressure and number of electrons in the bubble for ...

We investigate here how the surrounding gas influence the dynamics of drop impacts on a thin liquid film. We describe in details the entrapment of the gas bubble using numerical simulations with high enough mesh resolution. The bubble entrapment comes from viscous effect in the thin gas layer that need to be evacuated down the drop, creating a high pressure field that deforms the drop interface...

A male child with tetra-amelia, hypotrichosis, upward slanting palpebral fissures, lack of lacrimal openings, hypoplastic lacrimal ducts and sacs opening towards the exterior, prominent and bulbous nose, large downturned mouth, high narrow palate, bilateral preauricular pits, sacral dimple, bilateral undescended testes, and developmental retardation is reported. The parents were second cousins....

INTRODUCTION ILLUSTRATIONS CHAPTER I 1.1 1.2 1.3 COALESCENCE OF DISTILLED WATER DROPS Introduction Experimental Methods Experimental Results a) Dimple stability of water drops b) Effects of relative humidity and Impact velocity on coalescence c) Interference patterns for colliding water ii iii vii 1 1 2 6 6 drops 8 d) Retardation of water drop evaporation 13 e) Electrical effects on dimpling 14...

We analyze the stability of standing pulse solutions of a neural network integro-differential equation. The network consists of a coarse-grained layer of neurons synaptically connected by lateral inhibition with a nonsaturating nonlinear gain function. When two standing single-pulse solutions coexist, the small pulse is unstable, and the large pulse is stable. The large single pulse is bistable...