Cerebral aneurysms are bulges appearing on brain arteries. The development, growth and rupture has been intensively studied using numerical tools. We present a series of studies covering many of the open questions related to the boundary conditions used in numerical simulations, namely the inlet, outlet and the wall. The effect of boundary conditions cannot be overestimated; yet it received muc...

The rigid insoluble mucopeptide component of the gramnegative bacterial cell wall would appear to be easily separable from the lipopolysaccharide component by the phenol extraction procedures of Westphal, Luderitz, and Bister (1) and of Palmer and Gerlough (2). Indeed, purification of a mucopeptide “R” (rigid) layer, reported to be composed only of glucosamine, muramic acid, alanine, and glutam...

In recent years, computational structural analyses have emerged as important tools to investigate the mechanical response of stent placement into arterial walls. Although most coronary stents are expanded by inflating a polymeric balloon, realistic computational balloon models have been introduced only recently. In the present study, the finite element method is applied to simulate three differ...

1 ABSTRACT With uncertainty of energy prices and an increased interest in sustainability, more builders and designers are striving for dramatic levels of home energy efficiency. Performance of the home’s envelope is clearly critical in this endeavor. In colder climates, several builders are moving towards whole-wall thermal resistances above 30 fthr°F/Btu (4.9 m°C/W). While there are numerous h...

A new model for turbulent flows in porous media is developed. The spatialand time fluctuations in this new model are tied together and treated as a single quantity. This novel treatment of the fluctuations leads to a natural construction of the k and e type equations for rigid and isotropic porous media in which all the kinetic energy filtered in the averaging process is modeled. The same terms...

We describe a simple modification to a rigid endoscope so as to provide both high-quality conventional and confocal images of reasonably accessible regions of the body. This versatile system uses a structured illumination approach together with a conventional incoherent illumination source. Images taken in fluorescence are presented using this combined conventional and confocal endoscope.

Flexible joints are a key innovation in the evolution of upright coralline algae. These structures have evolved in parallel at least three separate times, allowing the otherwise rigid, calcified thalli of upright corallines to achieve flexibility when subjected to hydrodynamic stress. As all bending occurs at the joints, stress is amplified, which necessitates that joints be made of material th...

Sound propagation i gas-filled capillary-tube-type orous media was investigated. The capillary tubes were taken to be nominally straight with very small pores in the walls of the capillary tubes. The complex wave number and the characteristic mpedance of such media were evaluated. Application to ceramic samples having capillary pores with square cross sections and porous walls is developed as a...

What is a tree? The popular concept of a tree, which encompasses everything from treeferns and Joshua trees to coconut palms and oaks, confounds any simple botanical definition. Nevertheless, almost all ‘trees’ have one (rarely a few) above ground, perennial vegetative shoots, of a size requiring significant nonhydrostatic structural support. In a typical seed plant tree, this structural tissue...

It is believed that persistence of small populations of Mycobacterium tuberculosis in hosts underlies latent tuberculosis. Very little is known about the morphological and physiological nature of tubercle bacilli in latent TB. It is under discussion whether and how tubercle bacilli adapt to latent state and remain alive in face of damaging stressful conditions such as antibiotics and host immun...