arXiv subjects

Piotr Pawłowski

Publications and source records attributed to Piotr Pawłowski.

4 recordsLinked to original sources

arXiv2022

Microstructure Evolution of Solid Oxide Fuel Cell Anodes Characterized by Persistent Homology

Uncovering microstructure evolution mechanisms that accompany the long-term operation of solid oxide fuel cells is a fundamental challenge in designing a more durable energy system for the future. To date, the study of fuel cell stack degradation has focused mainly on electrochemical performance and, more rarely, on averaged microstructural parameters. Here we show an alternative approach in which an evolution of three-dimensional microstructural features is studied using electron tomography coupled with topological data analysis. The latter produces persistent images of microstructure before and after long-term operation of electrodes. Those images unveil a new insight into the degradation process of three involved phases: nickel, pores, and yttrium-stabilized zirconium.

cond-mat.mtrl-sci↗

arXiv2021

Light cluster production in central symmetric heavy-ion reactions from Fermi to GeV energies

Correlations and clustering are of great importance in the study of the Nuclear Equation of State. Information on these items/aspects can be obtained using Heavy-Ion reactions which are described by dynamical theories. We propose a dataset that will be useful for improving the description of light cluster production in transport model approaches. The dataset combines published and new data and is presented in a form that allows direct comparison of the experiment with theoretical predictions. The dataset is ranging in bombarding energy from 32 to 1930 A MeV. In constructing this dataset we put in evidence the existence of a change in the light cluster production mechanism that corresponds to a peak in deuteron production.

nucl-ex↗

arXiv2016

Alpha Cluster Model of Atomic Nuclei

Description of a nuclear system in its ground state and at low excitations based on the equation of state (EoS) around normal density is presented. In the expansion of the EoS around the saturation point additional spin polarization terms are taken into account. These terms, together with the standard symmetry term, are responsible for appearance of the $α$-like clusters in the ground state configurations of the N=Z even-even nuclei. At the nuclear surface these clusters can be identified as alpha particles. A correction for the surface effects is introduced for atomic nuclei. Taking into account an additional interaction between clusters the binding energies and sizes of the considered nuclei are very accurately described. The limits of the EoS parameters are established from the properties of the $α$, $^{3}$He and $t$ particles.

nucl-th↗

arXiv2004

Neutron halo and the impact-parameter dependence of the $π^+ - π^-$ asymmetry in heavy ion collisions

The theoretical nuclear physics predictions and experimental results on antiprotonic atoms lead to different proton and neutron spatial distributions. At CERN SPS energies production of positive and negative pions differs for $pp$, $pn$, $np$ and $nn$ scattering. These two facts lead to an impact parameter dependence of the $π^+$ to $π^-$ ratio in $^{208}Pb + ^{208}Pb$ collisions. A recent experiment at CERN seems to confirm qualitatively these predictions. The results for two models considered are almost identical. It may open a new possibility for determination of neutron density distribution in nuclei.

nucl-th↗