Boundary layers on stationary and rotating disks have received much attention since von Kármán’s @Z. Angew. Math. Mech. 1, 233 ~1921!# and Bödewadt’s @Z. Angew. Math. Mech. 20, 241 ~1940!# studies of the cases with disks of infinite radius. Theoretical treatments have focused on similarity treatments leading to conflicting ideas about existence and uniqueness, and where self-similar solutions e...

STUDY OBJECTIVE To determine whether manual ventilation during intrahospital transport of mechanically ventilated critically ill patients results in blood gas and/or hemodynamic abnormalities. DESIGN A single-blind prospective study evaluated arterial blood gas, blood pressure, heart rate, and arrhythmia changes during mechanical ventilation and manual transport ventilation. SETTING Univers...

We consider incompressible viscous flows between two transversely vibrating solid walls and construct an asymptotic expansion of solutions of the Navier–Stokes equations in the limit when both the amplitude of the vibration and the thickness of the oscillatory boundary layers (the Stokes layers) are small and have the same order of magnitude. Our asymptotic expansion is valid up to the flow bou...

We explore whether the continuum scaling behavior of the fracture energy of metals extends down to the atomistic level. We use an embedded atom method (EAM) model of Ni, thus bypassing the need to model strain-gradient plasticity at the continuum level. The calculations are performed with a number of different 3D periodic size cells using standard molecular dynamics (MD) techniques. A void nucl...

T-box genes encode putative transcription factors implicated in diverse developmental processes (Papaioannou, V.E. and Silver, L.M., 1998. BioEssays 20, 9-19). We have previously reported the embryonic expression patterns of T-box genes in mice (Chapman, D.L., Garvey, N., Hancock, S., Alexiou, M., Agulnik, S.I., Gibson-Brown, J.J., Cebra-Thomas, J., Bollag, R.J., Silver, L.M., Papaioannou, V.E....

The two-dimensional Smoluchowski equation is employed to study the effect of elongational perturbations on nematic liquid crystal polymers under a weak shear. We use the multiscale asymptotic analysis to show that 1 when the elongational perturbation is small relative to the weak shear, the orientational probability density function pdf tumbles periodically only in an intermediate range of poly...

-The effect of elevated pressure on the stability of the homogeneous bubbly flow regime in a gas-liquid bubble column is examined. Experiments were performed in a 0.15 m diameter bubble column operated at pressures in the range 0.1-1.3 MPa with nitrogen as the gas phase and water as the liquid phase. The transition from homogeneous to heterogeneous flow regime was determined by two procedures. ...

The spin-up and spin-down of a fluid in a rapidly-rotating, fluid-filled, closed half cone is studied both numerically and experimentally. This unusual set up is of interest because it represents a pathological case for the classical linear theory of Greenspan & Howard (J. Fluid Mech., 17, 385, 1963) since there are no closed geostrophic contours nor a denumerable set of inertial waves (even a ...

A phenomenological constitutive relation using the conventional J2-fiow isotropic hardening yield function as well as a threshold shear stress based yield function that governs a 'directionally preferred plastic component' of shear strain, developed by the authors in an earlier work, is used for the simulation of the shear band formation. The constitutive relation which is expressed as an expli...

Compaction bands are narrow planar zones of localized purely compressive (without shear) deformation that form perpendicular to the most compressive principal stress. Such bands have been observed in high porosity rocks in the laboratory and in the field. Because compaction presumably decreases permeability, these bands can act as barriers to flow within reservoirs. Reexamination of the results...