Recent simulations indicate that ellipsoids can pack randomly more densely than spheres and, remarkably, for axes ratios near 1.25:1:0.8 can approach the densest crystal packing (fcc) of spheres, with a packing fraction of 74%. We demonstrate that such dense packings are realizable. We introduce a novel way of determining packing density for a finite sample that minimizes surface effects. We ha...

BACKGROUND AND PURPOSE The International Subarachnoid Aneurysm Trial (ISAT) showed that patients with intracranial aneurysms treated with coil embolization have better clinical outcomes than those undergoing neurosurgical clipping. However some patients treated endovascularly have recurrence of aneurysms. Low packing density is often cited as a reason for recurrence. Coiling with hydrogel cover...

Coating hydrogel films or microspheres by an adsorbed colloidal shell is one synthesis method for forming colloidosomes. The colloidal shell allows control of the release rate of encapsulated materials, as well as selective transport. Previous studies found that the packing density of self-assembled, adsorbed colloidal monolayers is independent of the colloidal particle size. In this paper we d...

Self-assembled layers of alkyl chains grafted onto the surfaces of layered silicates, metal, and oxidic nanoparticles are utilized to control interactions with external media by tuning the packing density of the chains on the surface, head group functionality, and chain length. Characterization through experiment and simulation shows that the orientation of the alkyl layers and reversible phase...

The packing density of a permutation pattern π is the limiting value, n → ∞, of the maximum proportion of subsequences of σ ∈ Sn that are order-isomorphic to π. We generalize methods for obtaining lower bounds for the packing density of any pattern and demonstrate the methods’ usefulness when patterns are non-layered.

We bound several quantities related to the packing density of the patterns 1(l+ 1)l . . . 2. These bounds sharpen results of Bóna, Sagan, and Vatter and give a new proof of the packing density of these patterns, originally computed by Stromquist in the case l = 2 and by Price for larger l. We end with comments and conjectures.

We bound several quantities related to the packing density of the patterns 1( + 1) · · · 2. These bounds sharpen results of Bóna, Sagan, and Vatter and give a new proof of the packing density of these patterns, originally computed by Stromquist in the case = 2 and by Price for larger . We end with comments and conjectures.  2004 Elsevier Inc. All rights reserved.

We bound several quantities related to the packing density of the patterns 1(l+ 1)l . . . 2. These bounds sharpen results of Bóna, Sagan, and Vatter and give a new proof of the packing density of these patterns, originally computed by Stromquist in the case l = 2 and by Price for larger l. We end with comments and conjectures.

We review results about the density of typical lattices in R. This density is of the order of 2−n. We then obtain similar results for random (non-lattice) sphere packings in R: after suitably taking a fraction ν of centers of spheres in a typical random packing σ, the resulting packing τ has density C(ν)2−n with a reasonable C(ν). We obtain estimates of C(ν). 2000 Math. Subj. Class. 82B05.

What are the structural determinants of protein sequence evolution? A number of site-specific structural characteristics have been proposed, most of which are broadly related to either the density of contacts or the solvent accessibility of individual residues. Most importantly, there has been disagreement in the literature over the relative importance of solvent accessibility and local packing...