INTRODUCTION Simple turbulence models extended from two-dimensional (2D) methods and applied to 3D turbulent boundary layers (TBL) generally give poor results. The Reynolds stresses are complicated to model for 3D flows due to the fact that they depend strongly on history effects, flow skewing, pressure gradients, strain-rate, and other flow parameters (Simpson, 1995). A common assumption in th...

We show that if 0′ is c.e. traceable by a, then a is array non-computable. It follows that there is no minimal almost everywhere dominating degree, in the sense of Dobrinen and Simpson [DS04]. This answers a question of Simpson and a question of Nies [Nie09, Problem 8.6.4]. Moreover, it adds a new arrow in [Nie09, Figure 8.1], which is a diagram depicting the relations of various ‘computational...

forests are biologically diverse systems, representing some of the richest biological areas on earth. they offer a variety of habitats for plants, animals and micro-organisms. however, forest biodiversity is increasingly threatened as a result of deforestation, fragmentation, climate change and other stressors. biodiversity is the variation of life forms within a given ecosystem, biome, or on t...