Data Science

The coupling of spin, charge and lattice degrees of freedom results in the emergence of novel states of matter across many classes of strongly correlated electron materials. A model example is unconventional superconductivity, which is widely believed to arise from the coupling of electrons via spin excitations. In cuprate high-temperature superconductors, the interplay of charge and spin degrees of freedom is also reflected in a zoo of charge and spin- density wave orders that are intertwined with superconductivity ...

When cycloalkanes are enclosed in a nanometer-sized pore, they adapt their shape - similar to the induced fit concept described in #biochemistry. The molecules do not all behave in the same way and surprisingly start to move when there is a lack of space at 5K.

Pressure, together with temperature, electric, and magnetic fields, alters the system and allows for the investigation of the fundamental prop- erties of matter. Under applied pressure, the interatomic distances shrink, which modifies the interactions between atoms and may lead to the appearance of new (sometimes exotic) physical properties, such as pressure-induced phase transitions; quantum critical points; new structural, magnetic, and/or superconducting states; and changes of the temperature evolution and symmetry of the order parameters...

Operando X-ray absorption spectroscopy revealed a linear correlation between the amount of oxidic Fe²⁺ and the ambient temperature activity of Pt−FeO_x preferential carbon monoxide oxidation catalysts. The hydrogen prereduction temperature and pressure determines the amount of active Fe²⁺ sites for alumina- and silica-supported Pt−Fe catalysts. Catalyst deactivation is linked with the oxidation of these sites.

Researchers from the Max Planck Institute for Biological Intelligence, Google Inc. and the Paul Scherrer Institute published a new method and data resource that makes connectomic analyses of the entire larval zebrafish brain possible.

Data science (DS) and artificial intelligence (AI) methods opens up an immense range of new opportunities and challenges in the context of continuously enhancing the complex methodologies used as basis for nuclear safety assessments. To this aim, following discussions in the ETSON Technical Board on Reactor Safety, the PSI laboratory for reactor physics and thermal-hydraulics organized on October 20-21, 2022, an international workshop to review and discuss DS/AI within ETSON, the network of European research and expert organizations providing scientific support to national nuclear authorities. With close to 40 participants, the workshop, organized as a hybrid meeting, allowed to put in evidence that similarly as at PSI, a wide and growing range of developments with integration of DS/AI methods are currently taking place in order to complement and/or inform nuclear safety analysis methodologies.  

Light Water Reactors (LWRs) such as the ones operating in Switzerland work at relatively high temperatures and pressures. As a consequence, thermal-hydraulics experiments investigating relevant LWRs phenomena at prototypical conditions require test sections with relatively thick steel walls. This poses significant challenges for the implementation of suitable instrumentation to capture phenomena of interest, such as the flow regimes during transition from liquid to steam. The characterization of flow regimes in the presence of boiling is rather complex, and their better understanding would allow to develop mathematical modeling tools that can be used to optimize equipment and better assess safety margins. To perform in-situ measurements of the boiling process under high-pressure conditions, the team of authors from PSI, ETH, and the University of Michigan has developed a new high-fidelity and high-speed imaging system based on x-ray radiography, which provides high-resolution details on the boiling process while being non-intrusive. Since the instrumentation is located outside of the test section, it has also the advantage that can be easily moved to take measurements in different region of the test sections.