The NuSTAR view of the Seyfert Galaxy HE 0436-4717

We present the multi epoch spectral analysis of HE 0436-4717, a bright Seyfert 1 galaxy serendipitously observed by the high energy satellite NuSTAR four times between December 2014 and December 2015. The source flux shows modest variability within each pointing and among the four observations. Spectra are well modelled in terms of a weakly variable primary power law with constant photon index ($\Gamma$=2.01$\pm$0.08). A constant narrow \ion{Fe} K$\alpha$ emission line suggests that this feature has an origin far from the central black hole, while a broad relativistic component is not required by the data. The Compton reflection component is also constant in flux with a corresponding reflection fraction R=0.7$^{+0.2}_{-0.3}$. The iron abundance is compatible with being Solar (A$_{Fe}$=1.2$^{+1.4}_{-0.4}$), and a lower limit for the high energy cut-off E$_c$>280 keV is obtained. Adopting a self-consistent model accounting for a primary Comptonized continuum, we obtain a lower limit for the hot corona electron temperature kT$_e$>65 keV and a corresponding upper limit for the coronal optical depth of $\tau_e$<1.3. The results of the present analysis are consistent with the locus of local Seyfert galaxies in the kT$_e$-$\tau_e$ and temperature-compactness diagrams.Comment: accepted for publication in A&

Conceptual Analogies Between Multi-Scale Feeding and Feedback Cycles in Supermassive Black Hole and Cancer Environments

Adopting three physically-motivated scales (micro - meso - macro, which refer to mpc - kpc - Mpc, respectively) is paramount for achieving a unified theory of multiphase active galactic nuclei feeding and feedback, and it represents a keystone for astrophysical simulations and observations in the upcoming years. In order to promote this multi-scale idea, we have decided to adopt an interdisciplinary approach, exploring the possible conceptual similarities between supermassive black hole feeding and feedback cycles and the dynamics occurring in human cancer microenvironment.Comment: Multidisciplinary article on Frontiers of Oncology (published on May 11th 2021

Systematic Broad-band X-ray Study of super-Eddington Accretion onto Supermassive Black Holes. I. X-ray Continuum

We present the first systematic broad-band X-ray study of super-Eddington accretion onto SMBHs with simultaneous {\it NuSTAR} and {\it XMM-Newton} or {\it Swift}/XRT observations of a sample of 8 super-Eddington accreting AGN with Eddington ratio $1<\lambda_{\rm Edd}<426$. We find that the SEAMBHs show a steep primary continuum slope as expected for sources accreting in the super Eddington regime, mostly dominated by relativistic reflection. The Iron K$\alpha$ emission lines of the sources of our sample show relativistic broadening. In addition the equivalent widths of the narrow components of the Iron K$\alpha$ lines follow the 'X-ray Baldwin' effect, also known as the 'Iwasawa-Taniguchi' effect. We found a statistically significant correlation between the photon-index of the primary power-law and the Eddington ratio, consistent with past studies. Moreover, as expected for super-Eddington sources, the median value of the reflection fraction of the sources we analysed is a factor $\sim 2$ higher than the median reflection fraction value of the type\,1 AGN from the BASS sample. We are able to estimate the coronal temperature for three sources of our sample: Mrk\,382 ($kT_e=7.8$\,keV), PG\,0026+129 ($kT_e=39$\,keV) and IRAS\,04416+1215 ($kT_e=3$\,keV). Looking at the position of the SEAMBHs sources of our sample in the compactness-temperature diagram it appears that in super-Eddington AGN, as for lower Eddington ratio AGN, the X-ray corona is controlled by pair production and annihilation.Comment: Accepted for publication in Monthly Notices of the Royal Astronomical Societ

Laura Olivieri,a Claudio Pettinari, b Duane Choquesillo-Lazarte, c Amalia García-García,d Antonio Rodríguez-Diéguez d and Agustín Galindo

Hydrazones and their metal derivatives are very important compounds in medicinal chemistry due to their reported variety of biological activities, such as antibacterial, antifungal and anticancer action. Five hydrazone-pyrazolone ligands HL (n = 1-5) were prepared and fully characterized and their tautomerism was investigated in the solid state and solution. Five zinc(ii) complexes 1-5 of composition [Zn(HL)] (n = 1 and 2), [Zn(HL)(HO)] (n = 3 and 5) and [Zn(HL)] were synthesized and characterized by elemental analysis, IR, H, F, C, and N NMR spectroscopy, and ESI mass spectrometry. In addition, the structures of two ligands and three complexes were determined by single-crystal X-ray diffraction. The ligands HL and HL exist both in the NH,NH tautomeric form. Complexes 1 and 2 are mononuclear compounds, while complex 4 is a one-dimensional coordination compound. Density functional theory (DFT) calculations were carried out on proligands, their anions and all zinc complexes, confirming the experimental results, supporting IR and NMR assignments and giving proofs of the mononuclear diaqua structure of complexes 3 and 5. The antibacterial activity of the free ligands and the Zn(ii) complexes was established against Escherichia coli and Staphylococcus aureus, and a strong efficiency has been found for Zn(ii) complexes, particularly for the polynuclear 4 and the mononuclear diaqua complex 5, the latter containing a ligand with aliphatic and fluorinated substituents able to compromise the permeability of and disrupt the bacterial cell membrane.Thanks are due to the University of Camerino (Italy) for financial support. The research grant of Dr Laura Olivieri was funded under the frame of the project Nano4-Fresh – Nanomaterials for an environmentally friendly and sustainable handling of perishable products (PRIMA19_00246), which is part of the Partnership on Research and Innovation in the Mediterranean Area (PRIMA) Programme supported by the European Union and funded by the national funding bodies of Participating States (MUR in Italy is gratefully acknowledged). We thank the Marche Region for supporting this research by funding the two-year research grant of Dr Sonila Xhafa as part of the POR Marche FSE 2014–2020 P.I. 8.1 R.A. 8.5. Financial support from the Spanish Ministerio de Ciencia e Innovación (PGC2018-093443-B-I00) is gratefully acknowledged

Metal Organic Frameworks as Heterogeneous Catalysts in Olefin Epoxidation and Carbon Dioxide Cycloaddition

Metal–organic frameworks (MOFs) are a family of porous crystalline materials that serve in some cases as versatile platforms for catalysis. In this review, we overview the recent developments about the use of these species as heterogeneous catalysts in olefin epoxidation and carbon dioxide cycloaddition. We report the most important results obtained in this field relating them to the presence of specific organic linkers, metal nodes or clusters and mixed-metal species. Recent advances obtained with MOF nanocomposites were also described. Finally we compare the results and summarize the major insights in specific Tables, outlining the major challenges for this emerging field. This work could promote new research aimed at producing coordination polymers and MOFs able to catalyse a broader range of CO2 consuming reactions

Advanced functional coating for self-cleaning and anti-corrosion applications

This thesis is focused on the preparation of organic-inorganic hybrid systems with targeted properties. In particular, thesis presents the synthesis, characterization and application of two types of functional coating, which are hydrophobic / self-cleaning and anticorrosion coatings. Chapter 1 is dedicated to general introduction and the state of art of advanced functional coating. The chapter includes a brief description of the current functional market size and possible applications of functional coatings. Chapter 2 provides a general introduction of superhydrophobic coatings, their possible applications on the glass surface and methods to produce them. In the chapter 3, sol-gel methods has been describe in detail. The sol gel process by employed alkoxysilanes was used in this work to fabricate the functional coatings. Chapters 4, 5 and 6 describes the experimental works of this thesis. In the chapter 4, the solgel process and dip-coating technique were employed for the preparation of hydrophobic self-cleaning hybrid materials. The process has been optimized to obtain transparent and highly hydrophobic sol-gel coatings by using different alkoxysilane. These hybrid sol-gel coatings are a good alternative to provide anti-stick and easy-to-clean properties to glass substrates being quite easy to scale up. In the chapter 5, a method for the preparation of transparent superhydrophobic silica coatings on glass substrates via aerosol‐assisted chemical vapour deposition (AACVD) is described. A multi-layer process to produce dual scale silica nanoparticles films, by using different functional alkoxysilanes was investigated. In this study, a novel strategy to achieve highly transparent superhydrophobic glass surfaces using AACVD of alkoxysilanes, to produce surfaces with excellent durability is described. This shows great potential to obtain silica superhydrophobic films for large–scale applications Finally, in the chapter 6, a preliminary study about the protective barrier coating to protect the integrity of the silver from deleterious chemical degradation in a mirror structure is investigated. Sol-gel hybrid coating has been deposited on mirror to avoid corrosion degradation process of silver layer. Salt spray test was performed on mirror coated with hybrid coating and the results showed a no signs of corrosion on the mirror. The results indicate excellent barrier protection performance of the coating

Metal–organic frameworks for carbon dioxide capture

A review on the promising field of MOF-based carbon capture and storage is presented. We discuss here the main features of MOFs appli- cable for CO2 capture and separation, the linker functionalization role, and the most important CO2-binding sites as also the most efficient and significant technologies, and a systematic report on the high- and low-pressure CO2 capture

MOFs for Electrochemical Energy Conversion and Storage

Metal organic frameworks (MOFs) are a family of crystalline porous materials which attracts much attention for their possible application in energy electrochemical conversion and storage devices due to their ordered structures characterized by large surface areas and the presence in selected cases of a redox-active porous skeleton. Their synthetic versatility and relevant host-guest chemistry make them suitable platform for use in stable and flexible conductive materials. In this review we summarize the most recent results obtained in this field, by analyzing the use of MOFs in fuel and solar cells with special emphasis on PEMFCs and PSCs, their application in supercapacitors and the employment in batteries by differentiating Li-, Na- and other metal ion-batteries. Finally, an overview of the water splitting reaction MOF-catalyzed is also reported