Observation of heavy spin-orbit excitons propagating in a nonmagnetic background: The case of (Ba,Sr)2YIrO6

We present a combined experimental and theoretical study of the elementary magnetic excitations in Ba2YIrO6 and Sr2YIrO6 - the two most intensively discussed candidates for a new type of magnetic instability caused by exciton condensation. For both materials, high-resolution resonant inelastic x-ray scattering (RIXS) at the Ir L3 edge reveals sharp excitations around 370 and 650 meV energy loss, which we identify as triplet and quintet spin-orbit excitons. While the momentum-dependent RIXS spectra reveal that both the triplet and the quintet propagate coherently within the nonmagnetic background of the singlet sites, these modes remain fully gapped. The Ir-Ir exchange interactions in both double perovskites are therefore not strong enough to overcome the magnetic gap and, hence, our results exclude an intrinsic magnetic instability due to a condensation of magnetic excitations for both Ba2YIrO6 and Sr2YIrO6

Use and minimization of water in leather tanning processes

Minimization of water use and reuse applications within industry has recently gained importance within the context of water conservation efforts. The leather tanning industry is one of the subject industries due to large amount of water to be disposed of together with a high pollution load. The leather tanning industry has a complex structure in terms of materials, processes and manufacturing practices. Therefore a systematic approach is required to assess water use practice. In this study, bovine leather processing was taken as an example. An extensive study was conducted as on-site evaluations and questionnaires in the İstanbul Organized Leather Tanning District to assess water use practices, patterns and minimization trends. Results of the study were discussed and important aspects of water minimization practices have been pointed out.</jats:p

Corrosion Behavior of Galvanized Steel Exposed to Fusarium oxysporum f. sp. cumini Isolated from a Natural Biofilm

Fusarium spp. are prevalent fungi in water systems and also in biofilm layers developing upon metal surfaces associated with these systems. The present study investigated (i) the presence of Fusarium sp. in biofilms on galvanized steel surface exposed to potable water, and (ii) the effect of Fusarium sp. on corrosion behaviour of galvanized steel by electrochemical methods. The natural biofilm was formed on the galvanized steel surface in a laboratory-scaled test system. Molecular characterization of the tentative Fusarium isolate was carried out by sequencing of the internal transcribed spacer (ITS) regions. The metal coupons were exposed for 336 h to potato dextrose broth medium inoculated with Fusarium sp. The biofilm formation and corrosion products on the metal surfaces were investigated by scanning electron microscopy. The ITS sequences showed that the Fusarium sp. isolate was closely related to Fusarium oxysporum f. sp. cumini (98.97%). The electrochemical analysis revealed that although the test medium was corrosive for the metal, the presence of F. oxysporum f. sp. cumini accelerated the corrosion of galvanized steel. According to the results, this is the first study showing the presence of Fusarium sp. in the natural biofilm formed on the galvanized steel surface and also the effect of Fusarium sp. on corrosion behavior of the galvanized steel in aqueous environment