Durability of crystalline monumental stones in terms of their petrophysical characteristics

The durability of stone building materials is an issue of utmost importance in the field of monument conservation. In order to be able to preserve our built cultural heritage, the thorough knowledge of its constituent materials and the understanding of the processes that affect them are indispensable. The main objective of this research was to evaluate the durability of a special stone type, the crystalline stones, in correlation with their intrinsic characteristics, the petrophysical properties. The crystalline stones are differentiated from the cemented stones on the basis of textural features. Their most important specific property is the usually low, fissure-like porosity. Stone types of significant monumental importance, like the marble or granite belong to this group. The selected materials for this investigation, indeed, are a marble (Macael marble, Spain) and a granite (Silvestre Vilachán granite, Spain). In addition, an andesite (Szob andesite, Hungary) also of significant monumental importance was selected. This way a wide range of crystalline rocks is covered in terms of petrogenesis: stones of metamorphic, magmatic and volcanic origin, which can be of importance in terms of mineralogical, petrological or physical characteristics. After the detailed characterization of the petrophysical properties of the selected stones, their durability was assessed by means of artificial ageing. The applied ageing tests were: the salt crystallization, the frost resistance in pure water and in the presence of soluble salts, the salt mist and the action of SO2 in the presence of humidity. The research aimed at the understanding of the mechanisms of each weathering process and at finding the petrophysical properties most decisive in the degradation of these materials. Among the several weathering mechanisms, the most important ones were found to be the physical stress due to crystallization pressure of both salt and ice, the thermal fatigue due to cyclic temperature changes and the chemical reactions (mostly the acidic attack) between the mineral phases and the external fluids. The properties that fundamentally control the degradation processes, and thus the durability of stones were found to be: the mineralogical and chemical composition; the hydraulic properties especially the water uptake, the permeability and the drying; the void space structure, especially the void size and aperture size distribution and the connectivity of the porous space; and the thermal and mechanical properties. Because of the complexity of the processes and the high number of determining properties, no mechanisms or characteristics could be identified as typical for crystalline stones. The durability or alterability of each stone type must be assessed according to its properties and not according to the textural or petrophysical classification they belong to. Finally, a critical review of standardized methods is presented, based on which an attempt was made for recommendations of the most adequate methodology for the characterization and durability assessment of crystalline stones.

Comprehensive characterization of snowfall in terms of microphysical features, quantitative precipitation estimation and scavenging properties by in situ and remote sensing observations at an Antarctic coastal site

Snow plays a crucial role in the Earth's hydrological cycle and energy budget, making its monitoring necessary. In this context, ground-based radars and in situ instruments are essential thanks to their spatial coverage, resolution, and temporal sampling. Deep understanding and reliable measurements of snow properties are crucial over Antarctica to assess potential future changes of the surface mass balance (SMB) and define the contribution of the Antarctic ice sheet on sea-level rise. However, despite its key role, Antarctic precipitation is poorly investigated due to the continent's inaccessibility and extreme environment. In this framework, this Thesis aims to contribute to filling this gap by in-depth characterization of Antarctic precipitation at the Mario Zucchelli station from different points of view: microphysical features, quantitative precipitation estimation (QPE), vertical structure of precipitation, and scavenging properties. For this purpose, a K-band vertically pointing radar collocated with a laser disdrometer and an optical particle counter (OPC) were used. The radar probed the lowest atmospheric layers with high vertical resolution, allowing the first trusted measurement at only 105 m height. Disdrometer and OPC provided information on the particle size distribution and aerosol concentrations. An innovative snow classification methodology was designed by comparing the radar reflectivity (Ze) and disdrometer-derived reflectivity by means of DDA simulations. Results of classification were exploited in QPE through appropriate Ze-snow rate relationships. The accuracy of the resulting QPE was benchmarked against a collocated weighing gauge. Vertical radar profiles were also investigated to highlight hydrometeors' sublimation and growth processes. Finally, OPC and disdrometer data allowed providing the first-ever estimates of scavenging properties of Antarctic snowfall. Results presented in this Thesis give rise to advances in knowledge of the characteristics of snowfall in Antarctica, contributing to a better assessment of the SMB of the Antarctic ice sheet, the major player in the global sea-level rise.

Implications of Blockchain-Based Smart Contracts on Contract Law

Smart contracts are the most advanced blockchain applications. They can also be used in the contractual domain for the encoding and automatic execution of contract terms. Smart contracts already existed before the blockchain, but they take advantage of the characteristics of that technology. Namely, the decentralised and immutable characters of the blockchain determine that no single contracting party can control, modify, or interrupt the execution of smart contracts. As every new phenomenon, blockchain-based smart contracts have attracted the attention of institutions. For example, in its Resolution of 3 October 2018 on distributed ledger technologies and blockchain, the European Parliament has stressed the need to undertake an in-depth assessment of the legal implications,starting from the analysis of existing legal frameworks. Indeed, the present research thesis aims to verify how blockchain-based smart contracts fit into contract law. To this end, the analysis starts from the most discussed and relevant aspects and develops further considerations. Before that, it provides a detailed description and clarifications about the characteristics, the functioning, and the development of the technology, which is an essential starting point for a high-level quality legal analysis. It takes into considerations already existing rules concerning the use of technology in the life cycle of contracts, from vending machines to computable contracts, and verifies its applicability to blockchain-based smart contracts. The work does not limit to consider the mere technology, but some concrete scenarios of adoption of blockchain-based smart contracts in the contractual domain. Starting from the latter, it focuses on the implications of blockchain-based smart contracts on contract formation, contract performance, and applicable law and jurisdiction.

Robotic Approach in the Treatment of Locally Advanced (Stage IIIA-pN2) non Small Cell Lung Cancer after Induction Therapy

Introduction: Despite there are already many studies on robotic surgery as minimally invasive approach for non-small cell lung cancer (NSCLC) patients, the use of this technique for stage III disease is still poorly described. These are the preliminary results of our prospective study on safety and effectiveness of robotic approach in patients with locally advanced NSCLC, in terms of postoperative complications and oncological outcome. Methods: Since 2016, we prospectively investigated, using standardized questionnaire and protocol, 21 consecutive patients with NSCLC stage IIIA-pN2 (diagnosed by EBUS-TBNA) who underwent lobectomy and radical lymph node dissection with robotic approach after induction treatment. Then, we performed a matched case-control study with 54 patients treated with open surgery during the same period of time, with similar age, clinical and pathological tumor stage. Results: The individual matched population was composed of 14 robot-assisted thoracic surgery and 14 patients who underwent open surgery. The median time range of resection was inferior in the open group compared to robotic lobectomy (148 vs 229 minutes; P=0.002). Lymph nodes resection and positivity were not statistically significantly different (p=0.66 and p=0.73 respectively). No difference was observed also for PFS (P=0.99) or OS (P=0.94). Conclusions: Our preliminary results demonstrated that the early outcomes and oncological results of N2-patients after robotic lobectomy were similar to open surgery. Considering the advantages of minimally invasive surgery, robotic assisted lobectomy should be a safe approach also to patients with local advanced disease.