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Innovative methods for physicochemical and dynamic characterization of ambient aerosols and other environmental systems
Get PDFThe present Thesis reports the main scientific achievements in my PhD research activity based on the application of multivariate statistical methods for Environmental Chemistry (academic discipline: CHIM/12) and, in particular, in the treatment of atmospheric aerosols data. During the three-year PhD period, I have faced several topics which have led to the publication of eight scientific articles including three as the first author. My publications can be conceptually grouped into three distinct parts:
1) Design and optimization of innovative experimental methodologies for the analysis of Airborne Particulate Matter (PM) and data interpretation, as related to human health, air quality, and climate change.
2) Definition of practical guidelines and optimal use of PM low-cost sensors based on the Optical Particle Counting (OPC) developed on laser scattering devices.
3) Analysis of other environmental matrices (different from airborne particulate matter) and data interpretation.
Furthermore, this Thesis describes the preliminary results of other research work presently in progress including:
1) Physico-chemical and meteorological characterization of atmospheric aerosols in southern Spain as part of the FRESA project.
2) Study and characterization of the processes and dynamics of atmospheric aerosol in the touristic Pertosa-Auletta cave (Italy, SA).
3) Characterization and quantification of radionuclides in innovative building materials defined as “Geopolymers”.
The common thread of all my scientific investigation is multivariate statistics for environmental assessment purposes. Multivariate Statistics includes all the mathematical-statistical methods to study complex sets of data, a typical situation in environmental chemistry, in order to extract tangible and exhaustive quali-quantitative information. The term Chemometrics is going to often be used in this Thesis to indicate mathematical-statistical methods applied to Chemistry
Dry grinding technology for automotive gears manufacturing: process modeling and optimization
Get PDFThe following thesis focused on the dry grinding process modelling and optimization for automotive gears production. A FEM model was implemented with the aim at predicting process temperatures and preventing grinding thermal defects on the material surface. In particular, the model was conceived to facilitate the choice of the grinding parameters during the design and the execution of the dry-hard finishing process developed and patented by the company Samputensili Machine Tools (EMAG Group) on automotive gears. The proposed model allows to analyse the influence of the technological parameters, comprising the grinding wheel specifications. Automotive gears finished by dry-hard finishing process are supposed to reach the same quality target of the gears finished through the conventional wet grinding process with the advantage of reducing production costs and environmental pollution. But, the grinding process allows very high values of specific pressure and heat absorbed by the material, therefore, removing the lubricant increases the risk of thermal defects occurrence. An incorrect design of the process parameters set could cause grinding burns, which affect the mechanical performance of the ground component inevitably. Therefore, a modelling phase of the process could allow to enhance the mechanical characteristics of the components and avoid waste during production. A hierarchical FEM model was implemented to predict dry grinding temperatures and was represented by the interconnection of a microscopic and a macroscopic approach. A microscopic single grain grinding model was linked to a macroscopic thermal model to predict the dry grinding process temperatures and so to forecast the thermal cycle effect caused by the process parameters and the grinding wheel specification choice. Good agreement between the model and the experiments was achieved making the dry-hard finishing an efficient and reliable technology to implement in the gears automotive industry
Evaluation of different tools for agricultural water assessment at different spatial scales
Get PDFThe purpose of this study is to evaluate different regional tools developed to support irrigation water management, at different spatial scales, to assess their reliability and for identifying possible improvements for a concrete use to support farmers and irrigation consortia.
In the first section, a comprehensive sensitivity analysis to quantify the robustness and possible improvements of two agro-hydrological models (CRITERIA-1D and Aquacrop) is conducted at field scale. In the second section, a remote sensing crop classification is evaluated at district-scale, using farmer-reported information as a ground truth classification. In the third section, the two crops data are integrated in two modelling frameworks with different aims: CRITERIA-1D integrated with forecasting weather data and remote sensing classification; Irriframe integrated with observed weather data and farmers crop information. Measured irrigation withdrawals are used to evaluate the two modelling tools.
The sensitivity analysis shows the non-representativeness of regional datasets for the specific field application and, on average, models prove to be mostly sensitive to the shallow groundwater level, suggesting a denser piezometers network to better estimate irrigation water needs. The remote sensing crop classification presents a good agreement with land use information, although the identification of several potential irrigated areas not declared by the farmers. A fair correspondence between the estimated and measured seasonal volumes is found, except for the trends, mainly due to the non-consideration by the models of specific agronomical practices.
Overall, field-scale models application suggests more specific model settings and calibration, with focus on the capillary rise process simulated by the two models. On the contrary, the seasonal application allows irrigation consortia to meet legal requirements, even exploiting innovative technologies to forecast water use. More user-friendly modelling frameworks and greater collaboration between research and water actors should be also considered to make these tools more usable
Tensor-Train decomposition for image classification problems
Get PDFIn these last years a great effort has been put in the development of new techniques for automatic object classification, also due to the consequences in many applications such as medical imaging or driverless cars. To this end, several mathematical models have been developed from logistic regression to neural networks. A crucial aspect of these so called classification algorithms is the use of algebraic tools to represent and approximate the input data. In this thesis, we examine two different models for image classification based on a particular tensor decomposition named Tensor-Train (TT) decomposition. The use of tensor approaches preserves the multidimensional structure of the data and the neighboring relations among pixels. Furthermore the Tensor-Train, differently from other tensor decompositions, does not suffer from the curse of dimensionality making it an extremely powerful strategy when dealing with high-dimensional data. It also allows data compression when combined with truncation strategies that reduce memory requirements without spoiling classification performance. The first model we propose is based on a direct decomposition of the database by means of the TT decomposition to find basis vectors used to classify a new object.
The second model is a tensor dictionary learning model, based on the TT decomposition where the terms of the decomposition are estimated using a proximal alternating linearized minimization algorithm with a spectral stepsize.Negli ultimi anni si è registrato un notevole sviluppo di nuove tecniche per il riconoscimento automatico di oggetti, anche dovuto alle possibili ricadute di tali avanzamenti nel campo medico o automobilistico. A tal fine sono stati sviluppati svariati modelli matematici dai metodi di regressione fino alle reti neurali. Un aspetto cruciale di questi cosiddetti algoritmi di classificazione è l'uso di aspetti algebrici per la rappresentazione e l'approssimazione dei dati in input. In questa tesi esamineremo due diversi modelli per la classificazione di immagini basati sulla decomposizione Tensor-Train (TT). In generale, l'uso di approcci tensoriali è fondamentale per preservare la struttura intrinsecamente multidimensionale dei dati. Inoltre l'occupazione di memoria per la decomposizione Tensor-Train non cresce esponenzialmente all'aumentare dei dati, a differenza di altre decomposizioni tensoriali. Questo la rende particolarmente adatta nel caso di dati di grandi dimensioni. Inoltre permette, attraverso l'uso di opportune strategie di troncamento, di limitare notevolmente l'occupazione di memoria senza ricadute negative sulle performance di classificazione. Il primo modello proposto in questa tesi è basato su una decomposizione diretta del database tramite la decomposizione TT. In questo modo viene determinata una base che verrà di seguito utilizzata nella classificazione di nuove immagini. Il secondo è invece un modello di dictionary learning tensoriale sempre basato sulla decomposizione TT in cui i termini della decomposizione sono determinati utilizzando un nuovo metodo di ottimizzazione alternato con l'utilizzo di passi spettrali
Archaeological research and the regulation of finds and discoveries in the subsoil and the seabed. The provisions of the Code between implementation and perspectives of reform, also in light of a comparative analysis with French and Spanish experience.
Get PDFIl lavoro è volto all’approfondimento, anche in chiave comparatistica, della vigente normativa riguardante la tutela e la valorizzazione dei beni archeologici. Nell’ambito della disciplina predisposta nell’ordinamento italiano si sono prese le mosse dal regime delle scoperte e dei ritrovamenti, per passare successivamente all’approfondimento della tutela approntata nella legislazione nazionale anche con riferimento alle limitazioni alla libera disponibilità e circolazione. Una particolare attenzione è stata dedicata alla tutela del territorio in cui i beni archeologici sono inseriti e quindi alla tutela indiretta, ai vincoli ope legis e alla pianificazione paesaggistica, mentre una specifica trattazione ha riguardato il regime dell’archeologia preventiva e la valorizzazione e fruizione di aree e parchi archeologici nel reciproco interfacciarsi delle legislazioni regionali e delle linee guida emanate con il d.m. MiBAC 18 aprile 2012. Un’indagine articolata ha avuto per oggetto la tutela del patrimonio archeologico subacqueo e in particolare la Convenzione dell’UNESCO adottata a Parigi nel 2001, nonché la tutela sovranazionale dei beni culturali, con riferimento alla disciplina dell’Unione europea e a quella della Convenzione europea per la protezione del patrimonio archeologico del 16 gennaio 1992 e della Convenzione UNIDROIT del 24 giugno 1995 sui beni culturali rubati o esportati illegalmente. Hanno infine fatto seguito due specifiche indagini sulla tutela del patrimonio archeologico in Spagna e in Francia. Quanto alla prima si è esaminato l’attuale quadro costituzionale in cui si inserisce la tutela del patrimonio culturale con particolare attenzione alle disposizioni della Ley 16/1985 del 25 giugno 1985 e alla legislazione delle Comunidades autónomas. Per quanto riguarda la seconda una particolare attenzione è stata dedicata alla Legge 27 settembre 1941 che ha introdotto in Francia la prima disciplina organica relativa agli scavi e ai ritrovamenti archeologici. Nel quadro normativo vigente un’analisi particolareggiata è stata dedicata al Code du Patrimoine, il cui quinto libro è interamente dedicato all’archeologia.This work aims to examine the legislation in force on the protection and valorisation of archaeological heritage, also from a comparative perspective. Within in the framework of the Italian legal system, were considered the regulations concerning finds and discoveries and the limitations of free availability and circulation, in order to analyse in depth the protection created in the national legislation. Particular attention was paid to the protection of territory into which archaeological goods are transferred and therefore to the indirect protection, as well as the ope legis constraints and landscape planning. Furthermore, this study investigated the regime of preventative archaeology and the valorisation and usage of archaeological areas and parks in the reciprocal interfacing of regional legislation and the guidelines issued by the Ministerial Decree of 18 April 2012. A comprehensive investigation was undertaken on the protection of underwater archaeological heritage and in particular the UNESCO Convention adopted in Paris in 2001, as well as the supranational protection of cultural assets, with reference to the regulations of the European Union, the European Convention for the Protection of Archaeological Heritage of 16 January 1992 and the UNIDROIT Convention of 24 June 1995 on stolen or illegally exported cultural assets. This investigation was followed by two case studies on the protection of archaeological heritage in Spain and France. Regarding the former, the current constitutional framework was examined, with reference to the protection of cultural heritage provided by Ley 16/1985 of 25 June 1985 and the legislation of the Comunidades autónomas. With respect to the latter, particular attention was dedicated to the Law of 27 September 1941 which introduced in France the first organic regulation on excavations and archaeological finds. An extensive analysis was dedicated to the contemporary legal provisions afforded by the Code du Patrimoine, whose fifth book entirely provides for archaeology
Relationships between airborne pollen allergens and environmental factors.
Get PDFThis thesis is a collection of scientific papers resulting from my research activity during the PhD course in Earth, Life, and Environmental Sciences. The main subject of the thesis is the capability of pollen to trigger a hypersensitive reaction in different environmental conditions, and the need to better characterise such allergenicity in order to measure it. This topic is discussed from different perspectives, using ecological, morphological, and molecular approaches. The thesis starts by summarising the importance of green infrastructures in the cities, from economical and conservational perspectives. It then focalises on the lesser-known ecosystem disservices urban vegetation can provide, and in particular on pollen allergy, exploring its causes and illustrating possible ways to monitor, foresee, and mitigate the allergenic risk. The possibility to monitor the allergenicity of urban green areas is then examined in depth, with an original research paper that proposes a method standardisation for existing allergenicity indices (Specific Allergenic Index and Urban Green Zones Allergenicty Index), and compares the indices results to evaluate their effectiveness. At the end of the thesis, pollen allergenicity is also approached from a molecular perspective, by investigating pollen allergens release mechanisms in the context of pollen hydration and germination. In particular, in an unpublished original research paper, the nature of allergen-carrying extracellular nanovesicles (pollensomes) released by pollen is extensively studied on a non-allergenic pollen model, to understand their biological role and thus the environmental conditions that trigger their release. Moreover, the last paper reported in the thesis demonstrates the secretion of a potential pollen allergen, a low-molecular weight cyclophilin, during pollen germination under stressful conditions. The thesis concludes with a brief description of other scientific activities carried on during the PhD, that still need more scientific corroboration to be published
Towards the conservation of vulnerable marine large predators: morphometric, molecular and microchemical variation of historical sawfish rostra from Mediterranean collections
Get PDFSawfishes (Chondrichthyes, Pristidae) are considered one of the most endangered families among elasmobranchs. Extensive efforts are required worldwide to gather solid information on historical and recent changes in the composition/range of species.
In this study, we have implemented an integrative approach to characterize the species diversity and the abundance of historical rostra of sawfishes from museums and private collections of the Mediterranean area. The identification at the species level of 172 dried rostra was carried out through the integration of both traditional and geometric morphometric techniques with molecular tools, allowing the assessment of a robust methodical approach to discriminate species. In addition, we analysed 35 rostral teeth to clarify the past distribution of sawfish species considering the isotopic composition of oxygen and carbon. The morphometric, molecular, and geographical characterization of samples was accompanied by the preliminary evaluation of growth structures and the inspection of the strontium isotope composition in two teeth to unravel movement patterns of individuals across different salinities of water.
Results were integrated with currently available data from public repositories and showed that the historical specimens belonged to four nominal species: Pristis zijsron (81), Anoxypristis cuspidata (39), P. pristis (30), and P. pectinata (22). An identification error of 5.41% emerged in the morphological distinction of rostra between juvenile individuals of P. pectinata and P. zijsron. The new approach of carbon and oxygen isotopes, implemented for the first time in these taxa, permitted the identification of the high-probability habitat preferences of these benthopelagic elasmobranchs in about 50% of the analysed specimens.
Using this multidisciplinary approach, we successfully assigned the numerous museum rostra with lacking data to a given species and identified their candidate geographical origin, retrieving novel information and data for understanding the species distribution and ecology of past, sometimes locally/regionally extinct sawfish faunas
Comprehensive characterization of SDH-deficient GIST using NGS data and iPSC models
Get PDFGastrointestinal stromal tumors (GIST) are the most common di tumors of the gastrointestinal tract, arising from the interstitial cells of Cajal (ICCs) or their precursors. The vast majority of GISTs (75–85% of GIST) harbor KIT or PDGFRA mutations. A small percentage of GIST (about 10‐15%) do not harbor any of these driver mutations and have historically been called wild-type (WT). Among them, from 20% to 40% show loss of function of the succinate dehydrogenase complex (SDH), also defined as SDH‐deficient GIST. SDH-deficient GISTs display distinctive clinical and pathological features, and can be sporadic or associated with Carney triad or Carney-Stratakis syndrome. These tumors arise most frequently in the stomach with predilection to distal stomach and antrum, have a multi-nodular growth, display a histological epithelioid phenotype, and present frequent lympho-vascular invasion. Occurrence of lymph node metastases and indolent course are representative features of SDH-deficient GISTs. This subset of GIST is known for the immunohistochemical loss of succinate dehydrogenase subunit B (SDHB), which signals the loss of function of the entire SDH-complex. The overall aim of my PhD project consists of the comprehensive characterization of SDH deficient GIST. Throughout the project, clinical, molecular and cellular characterizations were performed using next-generation sequencing technologies (NGS), that has the potential to allow the identification of molecular patterns useful for the diagnosis and development of novel treatments. Moreover, while there are many different cell lines and preclinical models of KIT/PDGFRA mutant GIST, no reliable cell model of SDH-deficient GIST has currently been developed, which could be used for studies on tumor evolution and in vitro assessments of drug response. Therefore, another aim of this project was to develop a pre-clinical model of SDH deficient GIST using the novel technology of induced pluripotent stem cells (iPSC)
On the use of the exoskeleton for seismic improvement and integrated efficient technologies in existing buildings
Get PDFThe aim of this work is to investigate the seismic improvement obtained through external strengthening structures applied on existing reinforced concrete buildings. An innovative integration with pre-assembled technological envelope components is also presented with the aim of achieving a holistic renovation. Particular attention was paid to the timber solution with an innovative post-tensioned connection between cross-laminated timber panels, which was the subject of an experimental campaig
The J1030 field: a new window on early large scale structures and faint radio-galaxy populations
Get PDFThe correlations between the evolution of the Super Massive Black Holes (SMBHs) and their host galaxies suggests that the SMBH accretion on sub-pc scales (active galactice nuclei, AGN) is linked to the building of the galaxy over kpc scales, through the so called AGN feedback. Most of the galaxy assembly occurs in overdense large scale structures (LSSs). AGN residing in powerful sources in LSSs, such as the proto-brightest cluster galaxies (BCGs), can affect the evolution of the surrounding intra-cluster medium (ICM) and nearby galaxies. Among distant AGN, high-redshift radio-galaxies (HzRGs) are found to be excellent BCG progenitor candidates. In this Thesis we analyze novel interferometric observations of the so-called "J1030" field centered around the z = 6.3 SDSS Quasar J1030+0524, carried out with the Atacama large (sub-)millimetre array (ALMA) and the Jansky very large array (JVLA). This field host a LSS assembling around a powerful HzRG at z = 1.7 that shows evidence of positive AGN feedback in heating the surrounding ICM and promoting star-formation in multiple galaxies at hundreds kpc distances. We report the detection of gas-rich members of the LSS, including the HzRG. We showed that the LSS is going to evolve into a local massive cluster and the HzRG is the proto-BCG. we unveiled signatures of the proto-BCG's interaction with the surrounding ICM, strengthening the positive AGN feedback scenario. From the JVLA observations of the "J1030" we extracted one of the deepest extra-galactic radio surveys to date (~12.5 uJy at 5 sigma). Exploiting the synergy with the X-ray deep survey (~500 ks) we investigated the relation of the X-ray/radio emission of a X-ray-selected sample, unveiling that the radio emission is powered by different processes (star-formation and AGN), and that AGN-driven sample is mostly composed by radio-quiet objects that display a significant X-ray/radio correlation