Title of Dissertation: NFKB1 Gene Promoter Polymorphism and Unidirectional Laminar Shear Stress: Implications for NF-κB activation, eNOS Protein Expression and Endothelial Function Joon Young Park, Doctor of Philosophy, 2006 Directed by: Professor Michael D. Brown Department of Kinesiology Exercise stimulus can be defined as endothelial wall shear stress. In the endothelial cells, the nuclear f...

Incomplete mixing of reactive solutes is well known to slow down reaction rates relative to what would be expected from assuming perfect mixing. In purely diffusive systems, for example, it is known that small initial fluctuations in reactant concentrations can lead to reactant segregation, which in the long run can reduce global reaction rates due to poor mixing. In contrast, nonuniform flows ...

The paper presents an analytical model for the estimation of shear stress at the interface of adhesively bonded layers in laminated composites. For this purpose, a new shear stress function is proposed that accounts for the influence of shear lag in laminates assembled using adhesive layers of different types and thicknesses. In addition to the estimation of interfacial stress, the function can...

We present measurements of human blood hemolysis caused by laminar shear stresses ranging from 50 to 500 Pa for exposure times extending from 60 to 300 s using a Taylor-Couette device. A viscoelastic model is proposed that captures the response of the red blood cells to shear stress. The model is based on well-established mechanical properties of the red blood cell membrane, and shows good agre...

We review recent developments in the field of microrheometry and describe a new flexure-based microrheometer (FMR) that can make measurements of the steady shear viscosity of transparent or optically-opaque complex fluids using 1-10 μl samples. We document the complex microrheology that may arise in a typical consumer product such as a skin crème, when the microstructure of the multiphase mater...

The rate of viscous energy dissipation in a shear layer of incompressible Newtonian fluid with injection and suction is studied by means of exact solutions, nonlinear and linearized stability theory, and rigorous upper bounds. For large enough values of the injection angle a steady laminar flow is nonlinearly stable for all Reynolds numbers, while for small but nonzero angles the laminar flow i...

At low Reynolds numbers, laminar-turbulent transition occurs on the suction side of high-lift low-pressure turbine blades. The prediction of this flow is an important step in low-pressure turbine design. Thus the laminar-turbulent transition must be modeled or resolved. The flow around the high-lift low-pressure turbine blade T106C is predicted using RANS simulations, without and with transitio...

The rate of viscous energy dissipation in a shear layer of incompressible Newtonian fluid with injection and suction is studied by means of exact solutions, nonlinear and linearized stability theory, and rigorous upper bounds. The injection and suction rates are maintained constant and equal and this leads to solutions with constant throughput. For strong enough suction, expressed in terms of t...

Endothelial dysfunction caused by the combined action of disturbed flow, inflammatory mediators and oxidants derived from cigarette smoke is known to promote coronary atherosclerosis and increase the likelihood of myocardial infarctions and strokes. Conversely, laminar flow protects against endothelial dysfunction, at least in the initial phases of atherogenesis. We studied the effects of TNFα ...

Bacterial adhesion is a complex process influenced by many factors, including hydrodynamic conditions. They affect the transfer of oxygen, nutrients, and bacterial cells in a water supply and cooling systems. The aim of this study was to identify hydrodynamic effects on bacterial adhesion to and detachment from stainless steel surfaces. For this purpose we observed the behaviour of bacterium L....