Global fits to precision cosmological data which show that there is a dark energy component comprising about 2/3 of the total cosmological energy also hint that a dark energy with w = P/ρ < −1 is viable, even favored. Here we discuss implications of such a surprising w, including whether it jeopardizes vacuum stability. It appears to be secure in microscopic processes, but why bulk dark energy ...

After a short review of the arguments for the existence of Particle Dark Matter in the Universe, I list the most plausible candidates provided by particle physics, i.e. neutrinos, axions, and WIMPs. In each case I briefly describe how to estimate the relic density, and discuss attempts at detecting these particles. At the end I discuss my personal favorite, the lightest supersymmetric particle,...

In July 2014, Sweden’s full crisis response system engaged in a major operation as a small forest fire spun out of control, turning into the largest forest fire in Sweden in modern times. A number of investigations have been undertaken to understand the course of the fire and identify lessons for future crisis management. This paper presents one approach to identifying such lessons, the lessons...

Dark matter is presumably made of some new, exotic particle that appears in extensions of the Standard Model. After giving a brief overview of some popular candidates, I discuss in more detail the most appealing case of the supersymmetric neutralino.

Water injection strings in highly deviated wells are subjected to complex forces on the string bore. In this work, a mechanical model is developed for these forces and for those on downhole tools. On the basis of this model, and taking account of the characteristics of the string in different working conditions, a temperature field model and a pressure field model are introduced, and a statical...

Cracks emerge due to various forces or stresses. After discerning the cracks preferably by non-destructive techniques, there is a need to find the reason for their appearance. With very exact analysis of the shape, form and dimension of the cracks and their location on the structural elements, we can deduce the reason for their formation.  This makes, proposing a suitable solution for preventin...

Cracks emerge due to various forces or stresses. After discerning the cracks preferably by non-destructive techniques, there is a need to find the reason for their appearance. With very exact analysis of the shape, form and dimension of the cracks and their location on the structural elements, we can deduce the reason for their formation. This makes, proposing a suitable solution for preventing...

Structural engineers use design codes formulated to consider uncertainty for both reinforced concrete and structural steel design. For a simple one-bay structural steel frame, we survey typical uncertainties and compute an interval solution for displacements and forces. The naive solutions have large over-estimations, so we explore the Mullen-Muhanna element-by-element strategy, scaling, and co...

Rayleigh damping forces are commonly introduced in the numerical simulations of nonlinear structures run to assess structural performance in case of an earthquake. Their purpose is to account for energy dissipative mechanisms not otherwise explicitly represented in the model. When caused by interactions between the structure and its surrounding environment, energy dissipation is external to the...