Phonons are quantum elastic excitations ofcrystalline solids. Classically, they correspond to thecollective vibrations of atoms in ordered periodic structures.They determine the thermodynamic properties ofsolids and their stability in the case of structural transformations.Here we review for the first time the existingexamples of the phonon analysis of adsorption-inducedtransformations occurring in microporous crystallinematerials. We discuss the role of phonons in determiningthe mechanism of the deformations. We point outthat phonon-based methodology may be used as a predictivetool in characterization of flexible microporousstructures; therefore, relevant numerical tools must bedeveloped.

This work investigates the effects of neutron irradiation on nitrogen and hydrogen adsorption in boron-doped activated carbon. Boron-neutron capture generates an energetic lithium nucleus, helium nucleus, and gamma photons, which can alter the surface and structure of pores in activated carbon. The defects introduced by fission tracks are modeled assuming the slit-shaped pores geometry. Sub-critical nitrogen adsorption shows that nitrogen molecules cannot probe the defects created by fission tracks. Hydrogen adsorption isotherms of irradiated samples indicate higher binding energies compared to their non-irradiated parent samples.

We analyze a bi-gravity model based on the first order formalism, having as fundamental variables two tetrads but only one Lorentz connection. We show that on a large class of backgrounds its linearization agrees with general relativity. At the non-linear level, additional degrees of freedom appear, and we reveal the mechanism hiding them around the special backgrounds. We further argue that they do not contain a massive graviton, nor the Boulware-Deser ghost. The model thus propagates only one graviton, whereas the nature of the additional degrees of freedom remains to be investigated. We also present a foliation-preserving deformation of the model, which keeps all symmetries except time diffeomorphisms and has three degrees of freedom.

Radiative heat transfer (RHT) between two metallic nanoparticles clusters in both near field and far field areexplored using many-body radiative heat transfer theory implemented with the coupled electric and magneticdipole (CEMD) approach, which effectively takes into account the contribution of magnetic polarization ofmetallic nanoparticles on heat exchange. The effects of magnetic polarization, many-body interaction (MBI),fractal dimension, and relative orientation of the clusters on RHT were analyzed. The results show thatthe contribution of magnetically polarized eddy-current Joule dissipation dominates the RHT between Agnanoparticle clusters. If the electric polarization (EP approach) only is considered, the heat conductance will beunderestimated as compared with the CEMD approach in both near field and far field regime. The effect of MBIon the RHT between Ag nanoparticle clusters is insignificant at room temperature, which is quite different fromthe SiC nanoparticle clusters. For the latter, MBI tends to suppress RHT significantly. The relative orientationhas remarkable effect on radiative heat flux for clusters with lacy structure when the separation distance is in thenear field. While for the separation distance in far field, both the relative orientation and the fractal dimensionhas a weak influence on radiative heat flux. This work will help the understanding of thermal transport in denseparticulate system.

The DNA shows a high degree of spatial and dynamical organization over a broad range of length scales. It interacts with different populations of proteins and can form protein-DNA complexes that underlie various biological processes, including chromosome segregation. A prominent example is the large ParB-DNA complex, an essential component of a widely spread mechanism for DNA segregation in bacteria. Recent studies suggest that DNA-bound ParB proteins interact with each other and condense into large clusters with multiple extruding DNA-loops. In my talk, I present the Looping and Clustering model [1], a simple statistical physics approach to describe how proteins assemble into a protein-DNA cluster with multiple loops. Our analytic model predicts binding profiles of ParB proteins in good agreement with data from high precision ChIP-sequencing – a biochemical technique to analyze the interaction between DNA and proteins at the level of the genome. The Looping and Clustering framework provides a quantitative tool that could be exploited to interpret further experimental results of ParB-like protein complexes and gain some new insights into the organization of DNA.[1] Walter, J.-C., Walliser, N.-O., ... & Broedersz, C. P., New J. Phys. 20, 035002 (2018).

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