The Ruđer Bošković Institute (RBI; Croatian: Institut Ruđer Bošković, pronounced [instǐtuːt rûd͡ʑɛr bɔ̂ʃkɔʋit͡ɕ], IRB) is a research institute located in the Šalata neighborhood of Zagreb, Croatia, founded in 1950, which studies the sciences.
Key physicochemical parameters of Plitvice Lakes water were monitored over a three-year period at representative locations along the lake system. In situ tufa mineralization rates were determined by using glass substrates, revealing a pronounced downstream increase: the lowest rates occurred at the lake's source, while the highest were measured in the lake's outflow to Korana River. Strong seasonal patterns were also evident, with maximum deposition rate during summer. In situ-formed tufa consisted predominantly of calcite and magnesium calcite, while small amounts of the metastable polymorph vaterite were occasionally detected during early mineralization stages. Diatom frustules were consistently present in all samples, highlighting the interconnected roles of biotic and abiotic factors, including hydrodynamics, temperature, and water chemistry, in regulating tufa formation. Field observations were complemented by laboratory calcium carbonate precipitation experiments conducted in artificial karst water formulated to mimic the properties of Plitvice Lakes. Structural, morphological, and chemical comparisons showed excellent agreement between natural tufa and laboratory-precipitated calcium carbonate. These results demonstrate the suitability of the proposed experimental model system for future laboratory studies aimed at disentangling the environmental and anthropogenic controls on tufa formation.
Murunskite (K2FeCu3S4) is a layered sulfosalt chalcogenide that occupies a unique position between the cuprate and iron pnictide families: it shares electronic characteristics with the former and adopts the crystal structure of the latter. Despite a completely random distribution of magnetic Fe within a nonmagnetic Cu matrix, murunskite exhibits a well-defined quarter-zone antiferromagnetic transition at 97 K and complete orbital order below 30 K. These findings reveal the unexpected emergence of long-range order in a high-entropy-like environment. This inherent robustness to site disorder in a layered structure makes murunskite a paradigmatic system for further studies. Here, we investigate doping strategies in murunskite to assess how its electronic and magnetic properties can be tuned. Using melt-growth techniques, we achieve substitutions at the magnetic metal site (Fe), spacer cation (K), and sulfur ligand (S), which significantly influence transport and magnetic properties. In addition, we use ionic-liquid gating on the parent compound and observe a gate-dependent suppression of resistivity, confirming the potential for electrostatic control over transport. Our results demonstrate the chemical and electronic plasticity of murunskite, offering a valuable platform for co-engineering disorder, magnetism, and transport, and opening avenues to explore quantum phenomena in correlated and high-entropy materials.
This research highlights a fascinating parallel between the Megaparsec-scale cosmic web in space and a laboratory-created micro-scale particle web in laser plasma. We show that similar filamentary web structures on drastically different scales evolve from nonlinear-far from equilibrium - different physical processes. While the cosmic web is created by the gravitational collapse of dark matter and aggregation into galactic clusters, strings-filaments and voids, a microparticle web is created by the Brownian motion and aggregation of metal-oxide particles. Spatial intermittency - resulting from intermittent velocity and density fields-characterizes multifractal microparticle web as a mimic of the cosmic multifractal web. Based on selfsimilar hierarchical clustering of matter, the underlying processes create both webs with a (non-Gaussian) power law distribution of the particle number density, and of the cosmic matter density. This study reveals that variation of the metal-oxide microparticle density in the strings-resembles the large density variations of massive halos in the galactic filament-strings. Cantor set distribution of metal-oxide microparticle separation-intervals along the strings-mimics the Cantor set distribution of the intervals of mass sticking along the intergalactic filaments that connect galaxy clusters.
We develop a semiclassical framework to determine scaling dimensions of neutral composite operators in scalar conformal field theories. For the critical Ising lambda phi 4 theory in d = 4 - & varepsilon;, we obtain the full spectrum of composite operators built out of n fields transforming according to the various Lorentz representations to next-to-leading order in the double-scaling limit n -* infinity and lambda -* 0 with lambda n fixed. At any given order, the semiclassical expansion resums an infinite number of Feynman diagrams. Combining our results with existing perturbative computations further yields the complete five-loop scaling dimensions in the & varepsilon;expansion for the family of phi n operators. Finally, extrapolating the semiclassical results to three dimensions leads to a competitive alternative to existing methodologies.
Fe-Cr binary alloys serve as simplified model systems to study irradiation damage relevant to fusion structural materials. Here, Fe-3 %Cr and Fe-5 %Cr samples were irradiated with 4 MeV Fe ions under a dose rate of 4 x 10(-5) dpa/s across a linear thermal gradient (120 degrees C-480 degrees C) in a single experiment, enabling direct comparison of temperature and Cr content effects under identical conditions. Depth-resolved Laue micro-diffraction (similar to 10(-4) strain sensitivity), nanoindentation, and AFM reveal non-monotonic evolution of lattice strain and hardness: both decrease with temperature up to similar to 300 degrees C, then increase beyond. This turning point reflects changes defect mobility and solute-defect clustering, which stabilize damage. Fe-3 %Cr shows consistently higher strain and hardening than Fe-5 %Cr, especially at lower temperatures. Minimal change in post-indentation pile-up indicates limited softening or localization. These results highlight how Cr content and temperature jointly affect irradiation response, offering new insights into defect evolution in fusion-relevant alloys.
