Italy INAF Analysis Center Report

This report summarizes the activity of the Italian INAF VLBI Analysis Center. Our Analysis Center is located in Bologna, Italy and belongs to the Institute of Radioastronomy, which is part of the National Institute of Astrophysics. IRA runs the observatories of Medicina and Noto, where two 32-m VLBI AZ-EL telescopes are situated. This report contains the AC's VLBI data analysis activities and shortly outlines the investigations into the co-locations of space geodetic instruments

Italy INAF Data Center Report

This report summarizes the activities of the Italian INAF VLBI Data Center. Our Data Center is located in Bologna, Italy and belongs to the Institute of Radioastronomy, which is part of the National Institute of Astrophysics

c-axis transport and phenomenology of the pseudo-gap state in Bi2Sr2CaCu2O8+δBi_2Sr_2CaCu_2O_{8+\delta}

We measure and analyze the resistivity of $Bi_2Sr_2CaCu_2O_{8+\delta}$ crystals for different doping $\delta$. We obtain the fraction of carrier $\eta(T,\delta) = n_g/n_{TOT}$ that do not participate to the c-axis conductivity. All the curves $\eta(T,\delta)$ collapse onto a universal curve when plotted against a reduced temperature $x=[T-\Theta(\delta)]/\Delta^{*}(\delta)$. We find that at the superconducting transition $n_g$ is doping independent. We also show that a magnetic field up to 14 T does not affect the degree of localization in the (a,b) planes but widens the temperature range of the x-scaling by suppressing the superconducting phase coherence.Comment: 11 pages, 5 figures, submitted to Phys.Rev.

Introduction to the Proceedings of WGTTG2021

We describe the Italy-South Africa Research Program 2018–2020, focusing on the mobility scheme “Algebraic Graph Theory and Complex Networks” which supported a series of scientific initiatives between the University of Cape Town (Cape Town, South Africa) and the University of Naples Federico II (Naples, Italy) during the years 2018–2021. We sketch the relevant steps of the collaboration, focusing on the creation of a network of researchers between Italy and South Africa in the fields of Graph Theory and Combinatorics. In this context it becomes more relevant the role of the “Workshop on Graphs, Topology and Topological Groups 2021” and of the corresponding proceedings

Localization of planar acoustic reflectors from the combination of linear estimates

In this paper we present a simple yet effective method for estimating the geometry of an acoustic enclosure in three-dimensions. By capturing the acoustic impulse responses using a microphone array and a loudspeaker at different spatial locations we transform the localization of planar reflectors into the estimation of multiple linear reflectors. By decomposing the microphone array into co-planar sub-arrays the line parameters of the reflectors lying on the corresponding planes can be inferred using a geometric constraint. By intersecting these lines the actual lying plane of each reflector can be estimated. The proposed method is evaluated using a three-dimensional microphone array in a real conference room

Tunnel and thermal c-axis transport in BSCCO in the normal and pseudogap state

We consider the problem of c-axis transport in double-layered cuprates, in particular with reference to Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$ compounds. We exploit the effect of the two barriers on the thermal and tunnel transport. The resulting model is able to describe accurately the normal state c-axis resistivity in Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$, from the underdoped side up to the strongly overdoped. We extend the model, without introducing additional parameters, in order to allow for the decrease of the barrier when an external voltage bias is applied. The extended model is found to describe properly the c-axis resistivity for small voltage bias above the pseudogap temperature $T^{*}$, the c-axis resistivity for large voltage bias even below $T_c$, and the differential $dI/dV$ curves taken in mesa structures.Comment: 12 pages, 6 figures. Submitted to Superconductor Science and Technolog