Biomedical subjects

P Ilg

Publications and source records attributed to P Ilg.

3 recordsLinked to original sources

PubMed2000

Validity of a macroscopic description in dilute polymeric solutions

Derivation of macroscopic equations from the simplest dumbbell models is revisited. It is demonstrated that the onset of the macroscopic description is sensitive to the flows. For Peterlin's approximation [Makromol. Chem. 338, 44 (1961)] to Warner's finitely extensible nonlinear elastic spring-force model [Ind. Eng. Chem. Fundam. 11, 379 (1972)] (FENE-P), small deviations from the Gaussian solution undergo a slow relaxation before the macroscopic description sets on. Some consequences of these observations are discussed.

Journal Article↗

PubMed1999

Generating moment equations in the Doi model of liquid-crystalline polymers.

We present a self-consistent method for deriving moment equations for kinetic models of polymer dynamics. The Doi model [J. Polym. Sci., Polym. Phys. Ed. 19, 229 (1981)] of liquid-crystalline polymers with the Onsager excluded-volume potential is considered as an example. To lowest order, this method amounts to a simple effective potential different from the Maier-Saupe form. Analytical results are presented which indicate that this effective potential provides a better approximation to the Onsager potential than the Maier-Saupe potential. Corrections to the effective potential are obtained.

Journal Article↗

PubMed1992

A comparison of two methods for inserting lag screws.

This study compared the accuracy of two accepted methods of inserting lag screws. The ability of the two techniques to produce concentrically drilled holes between the inner and outer cortices, the ability to accurately overdrill a small hole, and the displacement of the cortices following application and tightening of the lag screw were investigated using an experimental model of bony cortices. The results indicate that when the gap between the cortices is large, both methods of lag screw insertion are equally inaccurate. For smaller gaps between the cortices, the drill guide technique is more accurate than the other.

Bone Screws↗