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Analisi di interazione dinamica terreno-struttura di infrastrutture: confronto tra metodi avanzati e semplificati
No full textValutare il comportamento dei sistemi geotecnici in condizioni sismiche risulta una sfida complessa a causa della combinazione di effetti legati all'interazione dinamica terreno-struttura (DSSI) e alla risposta sismica locale del sito. I metodi avanzati, come le analisi dinamiche non lineari complete, che integrano in un unico modello numerico la struttura, la fondazione e il terreno, rappresentano teoricamente lo strumento ideale per assicurare l'affidabilità dei risultati. Tuttavia, una significativa complessità di implementazione ne limita ancora oggi l'impiego ai fini applicativi, relegandolo sostanzialmente ad un contesto di ricerca, con poche applicazioni nella progettazione di nuove infrastrutture. Al contrario, sono ampiamente diffusi nella pratica ingegneristica corrente i metodi di analisi sismica semplificati che, trascurando gli effetti di interazione dinamica, sovente conducono a soluzioni progettuali non ottimali dal punto di vista economico o della sicurezza. Gli approcci disaccoppiati, come l'approccio per sottostrutture e i metodi di Newmark modificati, rappresentano un buon compromesso, essendo in molti casi in grado di cogliere gli aspetti principali della DSSI pur risultando meno esigenti dal punto di vista computazionale. In questa tesi vengono confrontati i risultati ottenuti con i diversi metodi di analisi citati, esaminando due casi studio reali: una paratia ancorata nel porto di Ravenna e una fondazione su pali di una pila tipo di un viadotto ferroviario AV/AC nella Pianura Veneta. In particolare, per le analisi dinamiche complete sono stati utilizzati modelli agli elementi finiti 2D e 3D con comportamento non lineare e dissipativo del terreno al fine di stimare le performance delle opere e definire una soluzione di riferimento. I risultati ottenuti suggeriscono che, se correttamente calibrati e validati, gli approcci disaccoppiati possono fornire risultati paragonabili a quelli delle analisi complete. Una potenziale implementazione nella pratica professionale appare pertanto fattibile e promettente; tuttavia, l’affidabilità dell’approccio in presenza di terremoti molto intensi o di depositi a rischio liquefazione rimane ancora da provare, lasciando ampio spazio a sviluppi futuri.Evaluating the seismic response of geotechnical systems is a complex engineering challenge due to dynamic soil-structure interaction (SSI) and site-specific earthquake ground response. State-of-the-art methods like coupled nonlinear dynamic analyses, which include in the same numerical model the structure, its foundation, and the surrounding soil, are widely recognized for their reliability but remain largely limited to the research context, with minimal application to actual infrastructure projects. In contrast, simplified seismic analysis methods that neglect dynamic interaction effects are widespread in ordinary design practice, often leading to either uneconomical or unsafe design solutions. Decoupled approaches, such as the substructure approach and modified Newmark methods, offer a balance by capturing main aspects of SSI while remaining less computationally demanding, making them particularly suitable for a potential implementation in design practice. This thesis compares the results of different seismic analysis methods by investigating two real-world case studies: an anchored sheet-pile quay wall in the port of Ravenna (Central Italy) and a pile foundation supporting a high-speed railway viaduct pier in the Venetian Plain (Northern Italy). 2D and 3D finite element models with soil nonlinear and hysteretic constitutive behavior are used to estimate seismic performance and define a benchmark solution. The results suggest that decoupled approaches, when properly calibrated and validated, can provide results comparable to those of more complex coupled analyses. However, its reliability under strong ground motions and in the presence of soils prone to liquefaction or cyclic softening still remains uncertain and requires further research. This work contributes to the advancement and validation of seismic analysis methods for geotechnical systems, hopefully providing valuable insights for both practitioners and academics
Transposable element dynamics in Xenopus laevis embryogenesis: a tale of two coexisting subgenomes
Get PDFThe African clawed frog Xenopus laevis has an allotetraploid genome consisting of two subgenomes referred as L relating to the Long chromosomes and S relating to the Short chromosomes. While the L subgenome presents conserved synteny with X. tropicalis chromosomes, the S subgenome has undergone rearrangements and deletions leading to differences in gene and transposable element (TE) content between the two subgenomes. The asymmetry in the evolution of the two subgenomes is also detectable in gene expression levels and TE mobility. TEs, also known as “jumping genes”, are mobile genetic elements having a key role in genome evolution and gene regulation. However, due to their potential deleterious effects, TEs are controlled by host defense mechanisms such as the nucleosome remodeling and deacetylase (NuRD) complex and the Argonaute proteins that mainly modify the heterochromatin environment. In embryogenesis, TEs can escape the silencing mechanisms during the maternal-to-zygotic transition when a transcriptionally permissive environment is created. Moreover, further evidence highlighted that the reactivation of TEs during early developmental stages is not the result of this genome-wide reorganization of chromatin but it is class and stage-specific, suggesting a precise regulation. In line with these premises, we explored the impact of TE transcriptional contribution in six developmental stages of X. laevis. Overall, the expression pattern referred to the entire set of transcribed TEs was constant across the six developmental stages and in line with their abundance in the genome. However, focusing on subgenome-specific TEs, our analyses revealed a distinctive transcriptional pattern dominated by LTR retroelements in the L subgenome and LINE retroelements in the S subgenome attributable to young copies. Interestingly, genes encoding proteins involved in maintaining the repressive chromatin environment were active in both subgenomes highlighting that TE controlling systems were active in X. laevis embryogenesis and evolved symmetrically
Preliminary assessment of a two-phase direct cooling of Lithium-Ion battery pack for e-bike mobility
Get PDFElectric mobility is playing an increasingly central role in emission reduction policies to mitigate climate change effect. During the operation of electric vehicles, the batteries may be subject to high variation of the required current, which can lead to a sudden increase in the cell temperature. If this condition occurs repeatedly, there would be a reduction in battery capacity and useful life, and autonomy reduction of the electric vehicle. In the worst case, this problem can lead to the thermal runaway. Therefore, cooling of electric vehicle propulsion systems is a fundamental issue for the electric mobility development. In this article we propose an innovative cooling system using a dielectric low boiling fluid in which the batteries are directly immersed. The system was tested on an electric bicycle under real operative conditions. A special test bench was realized, consisting of a real electric bicycle, a training roller to simulate the load due to road slope and an external electric motor to simulate the pedaling of the cyclist. The results show a substantial decrease in the temperature of the cells with the proposed cooling system and there was a marked improvement in the temperature uniformity of the cells inside the battery pack
The optrA, cfr(D) and vanA genes are co-located on linear plasmids in linezolid- and vancomycin-resistant enterococcal clinical isolates in Italy
No full textObjectives To characterize the optrA-, cfr(D)- and vanA-carrying linear plasmids detected in three MDR enterococcal clinical isolates.Methods Enterococcus faecium (868), E. faecium (1001) and Enterococcus faecalis (2048), which were linezolid- and vancomycin-resistant due to the presence of optrA, cfr(D) and vanA genes, were tested for their susceptibility to several antibiotics. Characterization of the genetic elements carrying antibiotic resistance genes and ST determination were achieved using WGS data. The plasmid topology was evaluated by S1-PFGE. Resistance gene transferability was assessed by filter-mating experiments.Results The linezolid- and vancomycin-resistant enterococci also showed resistance to tedizolid, chloramphenicol, tetracycline, erythromycin, ampicillin and levofloxacin. Both E. faecium 868 and E. faecium 1001 belonged to ST80 (included in clade A1), whereas E. faecalis 2048 was associated with ST6. WGS analysis revealed a plasmid co-localization of the optrA, cfr(D) and vanA genes. optrA was carried by Tn6674-like or Tn7695-like transposons; cfr(D) was associated with a truncated guaA gene, both flanked by IS1216 with opposite polarity; vanA was found on a Tn1546-like transposon containing IS1542 and IS1251 transposases. PFGE of S1 nuclease-treated and untreated DNAs displayed the linear topology of optrA-, cfr(D)- and vanA-harbouring plasmids. Only E. faecium 868 was able to transfer linezolid and vancomycin genes to an enterococcal recipient.Conclusions To the best of our knowledge this is the first report on the occurrence of a linear plasmid in E. faecalis. Linear plasmids can play a key role in the spread of oxazolidinone and glycopeptide resistance with serious consequences for public health
OutfitAI: shop the outfit with a deep learning-based intelligent expert system
Get PDFIn an age where consumer preferences are as diverse as they are dynamic, the ability to offer personalized fashion recommendations at scale remains a significant challenge for retailers. Consumers seek a shopping experience that not only understands their unique style preferences but also dynamically adapts to their evolving tastes. The fashion industry is at a crossroads, facing increasing consumer demand for personalization, sustainability and transparency in a rapidly evolving digital marketplace. Traditional retail practices, while rich in tradition and artistry, often struggle to up-to-date with the rapidly, ethically-conscious and technology-driven expectations of today’s consumers. “OutfitAI” is designed to address these challenges by leveraging the power of deep learning to revolutionize the fashion retail experience. By automating the process of background removal in fashion images, using advanced algorithms for personalized product matching, and integrating sustainability filters into the product discovery process, OutfitAI aims to deliver a shopping experience that is not only personalized and engaging, but also aligned with the ethical and environmental values of the contemporary consumer. Unlike existing solutions, OutfitAI uses state-of-the-art semantic segmentation for precise background removal, enabling detailed feature extraction from fashion images. This process enables accurate matching of user-uploaded images with similar fashion items from an extensive database of eco-friendly and ethically produced products sourced from leading e-tailers. Setting itself apart from the current state of the art, OutfitAI places a strong emphasis on ethical data use and privacy, implementing robust measures to ensure user privacy and transparency. It also pioneers the integration of sustainability into the digital fashion discovery process, promoting responsible consumption patterns among users. Through a comprehensive system architecture that combines technical innovation with a commitment to ethics and sustainability, OutfitAI not only addresses the technological needs of the fashion retail industry, but also responds to the growing demand for more responsible and transparent consumer technologies
Wood gasification biochar enhances soil carbon sequestration without affecting greenhouse gas fluxes or wheat yield in sub-alkaline soil
Get PDFThe agricultural sector plays a vital role in mitigating soil greenhouse gas (GHG) emissions and enhancing carbon sequestration. One promising approach is wood biochar produced through gasification, which generates both syngas and stable biochar. This study evaluates the effects of wood gasification biochar (WGB) on subalkaline soil under Mediterranean climate conditions. A field experiment was conducted over two cropping years, monitoring soil N2O, CH4, and CO2 fluxes, along with temperature and water content, for two treatments: unamended wheat (control) and wheat amended with 60 Mg ha−1 of WGB. Additionally, soil physicochemical properties at 0–10 cm and 10–40 cm depths and wheat yield were assessed. In the WGB treatment, soil N2O, CH4, and CO2 fluxes remained unchanged, though a slight increase in soil temperature (+0.1 °C) was observed. No significant differences were detected in soil pH, total and ammoniacal nitrogen, bulk density, or cation exchange capacity. However, soil nitric nitrogen levels significantly decreased. Soil carbon stock increased 2.2-fold at 0–10 cm and 1.4-fold at 10–40 cm, with this effect persisting into the second year. Wheat yield remained comparable between treatments, averaging ∼2.0 Mg ha−1 (control) vs. ∼1.8 Mg ha−1 (WGB) in year one and ∼3.9 Mg ha−1 vs. ∼3.1 Mg ha−1 in year two. These findings indicate that wood gasification biochar enhances soil carbon sequestration without affecting GHG emissions or wheat yield, reinforcing its potential for sustainable soil management and circular agricultur
Future scenarios of the sector of insect as food and feed in Europe
Get PDFThe study aims to analyse through scenario analysis the future market opportunities for products derived from insects for food and feed (IFF) in Europe. The embryonic state of the IFF industry and the lack of sufficient and detailed quantitative information did not allow the adoption of more quantitative models. Compared to standard statistical forecasting techniques, scenario analysis allows for considering the impact of future exogenous shocks and significant structural changes in the system under investigation. Organisational learning is best performed collectively. Scenario analysis is a very relevant part of this process and can lead to better strategy and action planning. The scenario time horizon was fixed to 2035, while the spatial framework was the European Union. The analysis involved a selected group of experts and stakeholders of the IFF sector to provide a shared knowledge basis that was exploited to define eight different scenarios. Two of the eight resulting scenarios are favourable for the IFF sector, and two outline adverse outcomes for the industry. The remaining four scenarios refer to contrasting situations for the IFF sector. Some implications emerge for the future development of the IFF industry: the embryonic state of the IFF business in the EU makes it very vulnerable to shocks; the crucial role of policy and regulatory framework in the insect sector, together with the different degrees of societal concerns for sustainability may strongly affect the development of IFF. Relevant aspects that emerge in some scenarios are the cooperation and industrial ecosystems with open innovation and collective IPR protection; the importance of dedicated credit; improvement of the knowledge system, and the circular economy potential of IFF for treating waste, especially in the feed sector
Continuous Proximal Monitoring of Diameter Variation from Root to Fruit
No full textProximal plant-based monitoring provides high-resolution data about trees, lead- ing to more precise orchard management and in-depth knowledge about tree physiology. The present work focuses on continuous real-time monitoring of olive cv. ‘Ascolana tenera’ over hourly intervals during the third stage of fruit growth (mesocarp cell expansion) under mild water stress conditions (ψStem above −2 MPa). This is achieved by mounting dendrometers on the root, trunk, branch, and fruit to assess and model the behavior of each organ. The diameter variation in each organ over different time intervals (daily, two-weeks, and throughout the entire experiment), as well as their hysteretic patterns relative to each other and vapor pressure deficit, are demonstrated. The results show different correlations between various organs, ranging from very weak to strongly positive. However, the trend of fruit versus root consistently shows a strong positive relationship throughout the entire experiment (R2 = 0.83) and a good one across various two-week intervals (R2 ranging from 0.54 to 0.93). Additionally, different time lags in dehydration and rehydration between organs were observed, suggesting that the branch is the most reactive organ, regulating de- hydration and rehydration in the tree. Regarding the hysteretic pattern, different rotational patterns and characteristics (shape) were observed among the organs and in relation to vapor pressure deficit. This research provides valuable insight into flow dynamics within a tree, models plant water relations and time lags in terms of water storage and transport, and could be implemented for precise olive tree water status detection
The role of prior information on consumer acceptance of insect-based food and feed in Europe: evidence from a discrete choice experiment
Get PDFInsects are a promising alternative source of protein and micronutrients. Their inclusion in human diets and as feed for animals destined for human consumption has been endorsed by the European Commission to promote the achievement of the Sustainable Development Goals (SDGs) of food security (SDG 2) and responsible production and consumption (SDG 12). However, in Germany, Italy and Portugal, their use as food is hampered by low consumer acceptance and unfamiliarity with insects as part of a regular diet. Previous research has demonstrated that modifying the choice architecture, such as providing additional information on positive insect consumption outcomes, affects consumers' choices. In this study, we analyze the effect of information on consumer preferences for insect-based and insect-fed chicken meatball alternatives in three European countries: Germany (N = 516), Italy (N = 502) and Portugal (N = 250). In particular, we inspect whether different information scenarios affect consumer preferences for insect-based food products as a more sustainable alternative to meat products using a discrete choice experiment (DCE) embedded in an experimental design. Results indicate that providing prior information about the sustainability of meat alternatives increases the acceptance of insect-based meat alternatives in Germany and Italy. However, there is no evidence that making the insect-protein content more salient is associated with an increased preference for insect-based meatballs
Assessing the Impact of Exam Preparation Process on Students’ Careers
Get PDFEducational Process Mining techniques leverage educational data to gather relevant insights on the corresponding processes, ultimately supporting the development of evidence-based strategies for their improvement. In this work, we analyze students’ exam preparation process to i) uncover process patterns describing students’ behaviors and ii) develop predictive models capable of predicting students’ performance regarding graduation times. The results of the analysis can be employed both to formulate improvements to the study curricula and to enable the early detection of students who are likely to struggle in their career, to support them at an early stage of their studies