33145 research outputs found
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Prove penali e segreti
No full textAll'interno di un'opera di fondamentale rilievo, destinata a fare il punto sulla nozione di prova nell'attuale sistema penale, lo scritto approfondisce il rapporto tra l'interesse all'accertamento del fatto nel processo penale e la tutela di alcuni valori, per lo più valori fondamentali protetti dalla Costituzione, che l'accertamento penale deve rispettare nel suo cammino
A Poincaré map for the horocycle flow on SL(2,Z) and the Stern-Brocot tree
No full textWe construct a Poincar ́e map Ph for the positive horocycle flow on the modular surface PSL(2,Z)\H, and begin a systematic study of its dynamical properties. In particular, we give a com- plete characterisation of the periodic orbits of Ph, and show that they are equidistributed with respect to the invariant measure of Ph and can be organised in a tree by using the Stern-Brocot tree of rational numbers. In addition we introduce a time-reparameterisation of Ph which gives an insight into the dynamics of the non-periodic orbits
CO2 captures and sequestration by gas hydrates in marine environments: chemical characterization of natural organic compounds, sediments and their influences
No full textClimate change is known to be predominantly caused by the increasing amount of greenhouse gases in the atmosphere, in particular as CO2. To prevent excessive accumulation of CO2 in the atmosphere, it is therefore necessary to implement countermeasures through capture and sequestration, that can slow down the increasing of carbon dioxide.
The sequestration of carbon dioxide (CO2) in the form of gas hydrates presents a promising strategy for mitigating climate change by securely storing CO2 in marine environments.
Gas hydrates are crystalline structures consisting of water molecules organized in cages which encapsulate different guest molecules, like CO2; they are formed at low temperature and high-pressure conditions, commonly found in deep-sea; thus, the marine environment offers ideal conditions for hydrate formation, with natural sediments acting as reservoirs [1].
This study focused on the characterization of natural occurring compounds, and sediments, and aims to analyse and uncover their effects on the CO2-gas hydrates formation; this characterization is important since most of scientific studies are focused on the addition of chemicals, that would nullify the properties of gas hydrates in the storage of carbon dioxide without further emission of compounds in the environment. To find their effects, different tools were needed, starting from the sampling of sediments and seawater, with their subsequent sample preparation for analytical analysis, exploiting pore water extraction from sediments and solid phase extraction for the pre concentration of natural occurring compounds. The analytes were then identified with chromatographic techniques like HPLC-DAD-FLD, HPLC-MS and Q-TOF. Conductivity and pH of seawater and pore water were evaluated, and the ionic composition were determined through IC and ICP-MS analysis. Characterization tools were then applied, both for the direct study of CO2-gas hydrates structure and for sediments role evaluation, exploiting FE-SEM and RAMAN studies [2].
In particular, the RAMAN results suggested that, examining the ice structure and the behaviour of the -OH vibrational bands, valuable information can be obtained and favourable used for predicting the structure of gas hydrates and understanding the interactions between water molecules and sediments during gas-hydrate formation.
The aim of this study falls within the PRIN 2022 PNRR project entitled “Reliable long-term CO2 storage as clathrate hydrates in seawater and marine sediments (CO2-RESTO)”, funded by the European Union – Next Generation EU and led by the University of Perugia, the University of Camerino, and the OGS Institute as a research unit
Synthesis, characterization and antibacterial activity of new Cu(II), Cu(I) and Ag(I) metal complexes with phenoxy-ketimine Schiff base ligands
No full textThe growing threat of antimicrobial resistance (AMR) poses a critical challenge to global health, driven by the misuse of existing antibiotics and a stagnant drug development pipeline. In this context, medicinal inorganic chemistry offers a promising platform for designing new therapeutic agents, particularly through metal-based compounds that provide unique chemical properties unattainable with purely organic molecules. Metallo-drugs have demonstrated potential activity in antimicrobial therapy, especially against multidrug-resistant pathogens. Among these, Schiff bases, versatile ligands known for their metal-chelating capabilities, have been widely investigated due to their broad-spectrum biological activities, including antimicrobial and anticancer effects[1]. Notably, Schiff base metal complexes, particularly those incorporating copper(II), exhibit enhanced biological efficacy compared to their free ligands. In this study, two phenoxy-ketimine Schiff base ligands, 2-(1-(benzylimino)ethyl)phenol (HLBSMe) and 2-((benzylimino)(phenyl)methyl)phenol (HLBSPh), were synthesized and used to prepare a series of Cu(II), Cu(I), and Ag(I) complexes, employing the lipophilic PPh3 and the hydrophilic PTA as co-ligands to stabilize the metal in +1 oxidation state[1]. All species were fully characterized both in the solid state and in solution. Interestingly, the single-crystal XRD of [Cu(LBSPh)2] shows a copper(II) ion in a slightly distorted square planar environment (Figure 1). The antimicrobial activity of the complexes as well as of the corresponding free ligands was evaluated against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive). Several complexes demonstrated significant antimicrobial activity, with some outperforming their parent ligands and approaching the efficacy of the reference antibiotic ciprofloxacin
Il regolamento EIDAS 2. La falsità della firma digitale.
No full textIl saggio esamina le novità apportate dal Regolamento dell'U.E. Eidas 2 nel contesto delle firme elettroniche. Il saggio analizza poi il tema dell'uso non autorizzato della chiave privata al fine di verificare quali sono le patologie dell'atto così posto in essere. In questa prospettiva viene in rilievo: (a) la differenza tra falsità e invalidità ed evidenziato che la falsità non equivale sempre a invalidità; (b) l’operare del principio dell’affidamento negoziale in base al quale un atto negoziale può avere efficacia in forza dell’apparenza