Our group is currently developing an intravenous respiratory assist device that uses a centrally located pulsatile balloon within a hollow fiber bundle to enhance gas exchange rate via active mixing mechanism. We tested the hypothesis that the non-symmetric inflation and deflation of the balloon lead to both nonuniform balloon-generated secondary flow and nonuniform gas exchange rate in the fib...

Human red cell permeability to the homologous series of methanol, ethanol, n-propanol, n-butanol, and n-hexanol was determined in tracer efflux experiments by the continuous flow tube method, whose time resolution is 2-3 ms. Control experiments showed that unstirred layers in the cell suspension were less than 2 X 10(-4) cm, and that permeabilities less than or equal to 10(-2) cm s-1 can be det...

Prediction of passive permeation rates of solutes across lipid bilayers is important to drug design, toxicology, and other biological processes such as signaling. The inhomogeneous solubility-diffusion (ISD) equation is traditionally used to relate the position-dependent potential of mean force and diffusivity to the permeability coefficient. The ISD equation is derived via the Smoluchowski equ...

Klinkenberg permeability is an important parameter in tight gas reservoirs. There are conventional methods for determining it, but these methods depend on core permeability. Cores are few in number, but well logs are usually accessible for all wells and provide continuous information. In this regard, regression methods have been used to achieve reliable relations between log readings and Klinke...

We propose a method to retrieve the effective constitutive parameters of a slab of bianisotropic metamaterial from reflection and transmission coefficients (or scattering parameters). In our retrieval method, only the scattering parameters in one propagation direction are used. Analytical inversion equations are derived in order to retrieve the effective parameters of the permittivity, permeabi...

OBJECTIVES To evaluate the diagnostic value of plasma protein levels for pulmonary vascular permeability and acute respiratory distress syndrome. During acute lung injury and acute respiratory distress syndrome, increased vascular permeability induces protein-rich fluid extravasation. We hypothesized that plasma protein levels predict increased vascular permeability and acute respiratory distre...

The gas permeability of plastic films is important in packaging, containment, and agricultural fumigation. Recently, an approach for estimating the mass transfer coefficient of vapors across a film was presented by Papiernik et al. (2001). The mass transfer coefficient is an intrinsic property of a film-chemical combination, independent of the concentration gradient maintained across the film. ...