Ball mills are common grinding equipment in mineral processing industries. Ball wear results from three mechanisms namely impact, abrasion and corrosion. Of these, the corrosion mechanism is the least investigated, due to its chemical-electrochemical nature. Therefore, the aims of this research were to investigate the grinding chemistry influence (slurry pH, solid percentage, water chemistry an...

We study a one-parameter family of billiard maps Tp given by the convex tables j.rIP + IyIP = 1 for p E [l, m]. We note that the topological entropy is positive if p $ {l, 2, a}. We study the linear stability of some periodic orbits and observe that the stability of these orbits changes for p = 2. For p $ { 1, 2, m}, there exist elliptic periodic orbits suggesting that Tp is not ergodic for all...

The minimizers of the anisotropic fractional isoperimetric inequality with respect to a convex body $ K in \mathbb{R}^n are shown be equivalent star bodies whenever is strictly and unconditional. From this Pólya-Szeg? principle for seminorms derived by using symmetrization bodies.

On planar graphs, many classic algorithmic problems enjoy a certain “square root phenomenon” and can be solved significantly faster than what is known to be possible on general graphs: for example, Independent Set, 3-Coloring, Hamiltonian Cycle, Dominating Set can be solved in time 2O( √ n) on an n-vertex planar graph, while no 2o(n) algorithms exist for general graphs, assuming the Exponential...