Scalar-isovector K¯ production close to threshold

The reaction pp → dK ⁺ˉ has been investigated at excess energies Q = 47.4 and 104.7MeV above the K ⁺ˉ threshold at COSY Jülich. Coincident dK⁺ pairs were detected with the ANKE spectrometer, and subsequently ∼ 2000 events with a missing ˉ invariant mass were identified, which fully populate the Dalitz plot. The joint analysis of invariant mass and angular distributions reveals s-wave dominance between the two kaons, in conjunction with a p-wave between the deuteron and the kaon pair, i.e. Kˉ production via the a ₀ ⁺(980) channel. Integration of the differential distributions yields total cross-sections of σ(pp → dK ⁺ˉ) = (38±2_stat±14_syst)nb and (190±4_stat±39_syst)nb for the low and high Q value, respectively.     

Vortex dynamics in the wake of a mechanical fish

A novel Stereo PIV technique, with improvements over other techniques, is presented. The key feature of the new technique is the direct measurement of calibration data at each point in space on the measurement grid, so that no interpolation is necessary. This is achieved through the use of a contiguous target which can be analysed using standard PIV processing software. The technique results in three-dimensional measurements of high accuracy with a significantly simpler calibration phase. This has the benefit of improving ease of use and reducing the time taken to obtain data. Thorough error analysis shows that while previously-described error trends are correct, additional facets of the technique can be optimised to allow highly accurate results. The new technique is rigorously validated here using pure translation and rotation test cases. Finally, the technique is used to measure a complex swirling flow within a cylindrical vessel.     

Blutnachweis

Ohne Zusammenfassung     

Continuous facility location on graphs

Mathematical Programming - We study a continuous facility location problem on undirected graphs where all edges have unit length and where the facilities may be positioned on the vertices as well...     

Is there a common reaction pathway for chromium sulfides as anodes in sodium-ion batteries? A case study about sodium storage properties of MCr2S4 (M = Cr,Ti, Fe)

Journal of Solid State Electrochemistry - We present new insights into the electrochemical properties of three metal sulfides MCr2S4 (M = Cr, Ti, Fe) probed as anode materials in...     

Bad boundary behavior in star-invariant subspaces I

We discuss the boundary behavior of functions in star-invariant subspaces (BH ²)^⊥, where B is a Blaschke product. Extending some results of Ahern and Clark, we are particularly interested in the growth rates of functions at points of the spectrum of B where B does not admit a derivative in the sense of Carathéodory.