Geometry and topology of CC and CQ states

We show that multipartite mixed bipartite CC and CQ states are geometrically and topologically distinguished in the space of states. They are characterized by non-vanishing Euler-Poincar\'{e} characteristics on the topological side and by the existence of symplectic structure on the geometric side.Comment: Corrected version, Accepted for publication in JM

The nature of triad interactions in active turbulence

Generalised Navier-Stokes (GNS) equations describing three-dimensional active fluids with flow-dependent narrow spectral forcing have been shown to possess numerical solutions that can sustain significant energy transfer to larger scales by realising chiral Beltrami-type chaotic flows. To rationalise these findings, we study here the triad truncations of polynomial and Gaussian GNS models focusing on modes lying in the energy injection range. Identifying a previously unknown cubic invariant for the triads, we show that their asymptotic dynamics reduces to that of a forced rigid body coupled to a particle moving in a magnetic field. This analogy allows us to classify triadic interactions by their asymptotic stability: unstable triads correspond to rigid-body forcing along the largest and smallest principal axes, whereas stable triads arise from forcing along the middle axis. Analysis of the polynomial GNS model reveals that unstable triads induce exponential growth of energy and helicity, whereas stable triads develop a limit cycle of bounded energy and helicity. This suggests that the unstable triads dominate the initial relaxation stage of the full hydrodynamic equations, whereas the stable triads determine the statistically stationary state. To test whether this hypothesis extends beyond polynomial dispersion relations, we introduce and investigate an alternative Gaussian active turbulence model. Similar to the polynomial case, the steady-state chaotic flows in the Gaussian model spontaneously accumulate non-zero mean helicity while exhibiting Beltrami statistics and upward energy transport. Our results suggest that self-sustained Beltrami-type flows and an inverse energy cascade may arise generically in the presence of flow-dependent narrow spectral forcing

Evaluation of the impact of reducing national emissions of SO2 and metals in Poland on background pollution using a bioindication method.

Changes in environmental pollution by S, Cd, Cu, Pb and Zn in 2006-2014 were evaluated using a bioindication method. This method was based on measurements of pollutants in Scots pine (Pinus sylvestris L.) needles. The measurements were performed in the Chojnowskie Forests, a region recognized as a background area for central Poland. The changes in the contents of sulfur (S) and metals in needles were not comparable with the changes in the global emissions of the pollutants in Poland. On average, the pollution level in the study area decreased by 9.9% for S, 61.4% for Pb, 22.5% for Cd, 11.7% for Zn and 10.4% for Cu. During the same period, global emissions in Poland decreased by 38.1% for S, 8.0% for Pb, 63.2% for Cd, 11.7% for Zn and 14.0% for Cu. Therefore, the differences in the changes in emissions and the needle contents of each element should be examined separately which was not a goal of this study. However, the discrepancy between these results did not prevent the use of bioindication methods. Evaluation of pollutant contents in plants reflected their incorporation in biological processes rather than air or soil pollution levels

THE SOLID FINE PRECIPITATES BEHAVIOUR IN FESICR SOLUTION DURING LADLE RAFINATION

Possibility of FeSiCr alloys production, with low content of carbon, in industrial conditions depends upon various factors like temperature of the solution, refining time, chemical compositions and others. In order to identify the evolution and behavior of solid inclusions in the solution, laboratory tests for alloys at high temperatures of 1400-1500 degrees C have been carried out. For identifying the trajectory of inclusions, numerical simulations, in industrial conditions, have been performed for velocity and temperature distribution in a ladle furnace. Microscopy identification of selected inclusions, important from industrial refining viewpoint, has also been performed. The paper summarizes results of theoretical calculations and laboratory tests for ultra low carbon (ULC) FeSiCr alloys