An engineering lesson derived from the tragedies of the 9/11 Pentagon crash and Hurricane Katrina is the importance of resiliency in designing for multiple hazards. In the case of the Pentagon, the energy-absorbing capacity, redundancy, and continuity of the structural frame reduced the consequences of the unanticipated action. In Katrina, the hurricane protection system breached in forty-six p...

This article examines the relationship between warfare and the media, arguing that both terrorists and conventional warfare planners in the Pentagon factor communications and public relations into their planning. In this regard, the article sketches out how the Pentagon developed a new genre of ‘public relations-ized’ warfare – warfare planned, not only as a military exercise, but as a televisu...

Carbon, the basic building block of our universe, enjoys a vast number of allotropic structures. Owing to its bonding characteristic, most carbon allotropes possess the motif of hexagonal rings. Here, with first-principles calculations, we discover a new metastable three-dimensional carbon allotrope entirely composed of pentagon rings. The unique structure of this Pentagon Carbon leads to extra...

The quality of the software design often has a major impact on the quality of the final product and the effort for development and evolution. A number of quality assurance (QA) approaches for inspection of early-life-cycle documents have been empirically evaluated. An implicit assumption of these studies was: an investment into early defect detection and removal saves higher rework cost. The co...

objectives:  the efficacy of adding platelet-rich plasma (prp) to demineralized freeze-dried bone allograft (dfdba) in order to improve the clinical and radiographic results obtained in treatment of deep periodontal intrabony defects has yet to be fully elucidated. materials ­and methods: this double blind, split-mouth randomized controlled clinical trial was conducted on 12 patients with two c...

Defect engineering is used to augment the porosity of MIL-100. Incorporation defects leads structural collapse and ultimately causes amorphisation. Pair distribution function analysis reveals a stepwise hierarchical structure.

Abstract The five circles in the classical Pentagon theorem of Miquel are given as circumcircles certain triangles pentagon. If one chooses instead other triangles, gets a different configuration circles. This resulting carries three families concyclic quadruples points. Together with this gives total 20 radical axes each two these twenty all concurrent.

It is shown that an equilateral convex pentagon tiles the plane if and only if it has two angles adding to 180 o or it is the unique equilateral convex pentagon with Although the area of mathematical tilings has been of interest for a long time there is still much to be discovered. We do not even know which convex polygons tile the plane. Furthermore, for those polygons which do tile, new tilin...

We show that solutions of Pentagon equations lead to solutions of the Tetrahedron equation. The result is obtained in the spectral parameter dependent case. URA 1436 ENSLAPP du CNRS, associée à l’Ecole Normale Supérieure de Lyon et au Laboratoire d’Annecy de Physique des Particules. email: [email protected] Ref. ENSLAPP xxx/93 November 1993