Hydroelastic impacts of deformable wedges

This work investigates the slamming phenomenon experienced during the water entry of deformable bodies. Wedges are chosen as reference geometry due to their similarity to a generic hull section. Hull slamming is a phenomenon occurring when a ship re-enters the water after having been partially or completely lifted out the water. While the analysis of rigid structures entering the water has been extensively studied in the past and there are analytical solutions capable of correctly predicting the hydrodynamic pressure distribution and the overall impact dynamics, the effect of the structural deformation on the structural force is still a challenging problem to be solved. In fact, in case of water impact of deformable bodies, the dynamic deflection could interact with the fluid flow, changing the hydrodynamic load. This work investigates the hull-slamming problem by experiments and numerical simulations of the water entry of elastic wedges impacting on an initially calm surface. The effect of asymmetry due to horizontal velocity component or initial tilt angle on the impact dynamics is also studied. The objective of this work is to determine an accurate model to predict the overall dynamics of the wedge and its deformations. More than 1200 experiments were conducted by varying wedge structural stiffness, deadrise angle, impact velocity and mass. On interest are the overall impact dynamics and the local structural deformation of the panels composing the wedge. Alongside with the experimental analysis, numerical simulations based on a coupled Smoothed Particle Hydrodynamics (SPH) and FEM method are developed. The experimental results provide evidence of the mutual interaction between hydrodynamic load and structural deformation. It is found a simple criterion for the onset of fluid structure interaction (FSI), giving reliable information on the cases where FSI should been taken into account.

Effects of Global Warming on Berry Composition of cv. Sangiovese: Biochemical and Molecular Aspects and Agronomical Adaptation Approaches

Wine grape must deal with serious problems due to the unfavorable climatic conditions resulted from global warming. High temperatures result in oxidative damages to grape vines. The excessive elevated temperatures are critical for grapevine productivity and survival and contribute to degradation of grape and wine quality and yield. Elevated temperature can negatively affect anthocyanin accumulation in red grape. Particularly, cv. Sangiovese was identified to be very sensitive to such condition. The quantitative real-time PCR analysis showed that flavonoid biosynthetic genes were slightly repressed by high temperature. Also, the heat stress repressed the expression of the transcription factor “VvMYBA1” that activates the expression of UFGT. Moreover, high temperatures had repressing effects on the activity of the flavonoids biosynthetic enzymes “PAL” and “UFGT”.Anthocyanin accumulation in berry skin is due to the balance between its synthesis and oxidation. In grape cv. Sangiovese, the gene transcription and activity of peroxidases enzyme was elevated by heat stress as a defensive mechanism of ROS-scavenging. Among many isoforms of peroxidases genes, one gene (POD 1) was induced in Sangiovese under thermal stress condition. This gene was isolated and evaluated via the technique of genes transformation from grape to Petunia. Reduction in anthocyanins concentration and higher enzymatic activity of peroxidase was observed in POD 1 transformed Petunia after heat shock compared to untrasformed control. Moreover, in wine producing regions, it is inevitable for the grape growers to adopt some adaptive strategies to alleviate grape damages to abiotic stresses. Therefore, in this thesis, the technique of post veraison trimming was done to improve the coupling of phenolic and sugar ripening in Vitis vinifera L. cultivar Sangiovese. Trimming after veraison showed to be executable to slow down the rate of sugar accumulation in grape (to decrease the alcohol potential in wines) without evolution of the main berry flavonoids compounds.

Investigation of the Impacts of Parental Chronic Illness on Youth Caregiving Experiences and Psychosocial Adjustment.

Objective: Parental chronic illness has an impact on several aspects of offspring’s life. Three major impediments to research progress in this field are undeveloped and untested theoretical frameworks, no clear conceptualization of youth caregiving, and no available instrument to assess such construct in Italian. To address these weaknesses, the aims of this PhD dissertation were: (1) to investigate the psychometric properties of the Italian version of the Young Caregiver of Parents Inventory-Revised (YCOPI-R); (2) to empirically examine a model of the effects of parental illness on youth and family functioning innovatively analyzing the role of psychological flexibility; (3) to test a refined conceptualization of youth caregiving. Methods: A total of 501 adolescents aged 11 to 24 (295 young caregivers and 206 young noncaregivers) completed a questionnaire regarding youth caregiving, parental illness, and youth adjustment. In the first study, young caregivers were compared to noncaregivers, while the other studies used only the young carers subgroup. Results: The first study indicated that the Italian version of the YCOPI-R demonstrated sound psychometric and was able to discriminate between young caregivers and noncaregivers. The second study underlined the key protective role of psychological flexibility in shaping youth adjustment and family functioning in the context of parental illness. The third study innovatively clarified the nature of youth caregiving, indicating that it is a tripartite construct related to both positive and negative youth adjustment outcomes. Conclusions. This PhD project drew attention towards youth of chronically ill parents, a segment of the young population which is presently almost completely neglected in Italy by health policies and healthcare providers. This PhD project ultimately shed light into the processes through which parental illness results in detrimental youth outcomes and highlighted avenues for interventions that target empirically supported mechanisms which ameliorate the detrimental effects of parental illness on youth.

Impacts of trace element pollution on sewage sludge and soil-plant systems: developing remediation techniques and assessing plant uptake prevention measures

Trace Elements (TEs) pollution is a significant environmental concern due to its toxic effects on human and ecosystem health and its potential to bioaccumulate in the food chain and to threaten species survival, leading to a decline in biodiversity. Urban areas, industrial and mining activities, agricultural practices, all contribute to the release of TEs into the environment posing a significant risk to human health and ecosystems. Several techniques have been developed to control TEs into the environment. This work presents the findings of three-year PhD program that focused on research on TEs pollution. The study discusses three fundamental aspects related to this topic from the perspective of sustainable development, environmental and human health. (1) High levels of TEs contamination prevent the use of sewage sludge (SS) as a fertilizer in agriculture, despite its potential as a soil amendment. Developing effective techniques to manage TEs contamination in SS is critical to ensure its safe use in agriculture and promote resource efficiency through sludge reuse. Another purpose of the study was to evaluate different strategies to limit the TEs uptake by horticultural crops (specifically, Cucumis Melo L.). This study addressed the effect of seasonality, Trichoderma inoculation and clinoptilolite application on chromium (Cr), copper (Cu) and lead (Pb) content of early- and late-ripening cultivars of Cucumis Melo L.. Finally, the accumulation of copper and the effect of its bioavailable fraction on bacterial and fungal communities in the rhizosphere soil of two vineyards, featuring two different varieties of Vitis vinifera grown for varying lengths of time, were evaluated.

Life Cycle Assessment of Peach Nectar: a comparative analysis between conventional and bioenergy-from-waste integrated food chains

Modern food systems are characterized by a high energy intensity as well as by the production of large amounts of waste, residuals and food losses. This inefficiency presents major consequences, in terms of GHG emissions, waste disposal, and natural resource depletion. The research hypothesis is that residual biomass material could contribute to the energetic needs of food systems, if recovered as an integrated renewable energy source (RES), leading to a sensitive reduction of the impacts of food systems, primarily in terms of fossil fuel consumption and GHG emissions. In order to assess these effects, a comparative life cycle assessment (LCA) has been conducted to compare two different food systems: a fossil fuel-based system and an integrated system with the use of residual as RES for self-consumption. The food product under analysis has been the peach nectar, from cultivation to end-of-life. The aim of this LCA is twofold. On one hand, it allows an evaluation of the energy inefficiencies related to agro-food waste. On the other hand, it illustrates how the integration of bioenergy into food systems could effectively contribute to reduce this inefficiency. Data about inputs and waste generated has been collected mainly through literature review and databases. Energy balance, GHG emissions (Global Warming Potential) and waste generation have been analyzed in order to identify the relative requirements and contribution of the different segments. An evaluation of the energy “loss” through the different categories of waste allowed to provide details about the consequences associated with its management and/or disposal. Results should provide an insight of the impacts associated with inefficiencies within food systems. The comparison provides a measure of the potential reuse of wasted biomass and the amount of energy recoverable, that could represent a first step for the formulation of specific policies on the integration of bioenergies for self-consumption.

Towards Europe 2050: the role of institutions, EU research, and citizens for climate justice. The urban challenge in Amsterdam, Bilbao, Freiburg, and Lisbon.

The climate crisis is the greatest challenge humanity has ever faced, and in 2023 the average global temperature reached new records, prompting the UN Secretary General to declare that 'the era of global warming is over, and the era of global boiling has arrived'. In this context, urban areas play a key role, and can be considered a bottleneck of the climate crisis. The European Commission is investing billions of euros in research and innovation projects in urban areas, while the European Green Deal strategy has the ambition of making Europe the first carbon-neutral continent on the planet by 2050. However, studies and research show that the causes of the climate crisis are rooted in an economic system that produces profound inequalities, and the very solutions to address the consequences of global warming risk deepening them. In this context, the role of cities is not only to decarbonise their urban fabric, but to build solutions to the social challenge posed by the climate crisis, promoting paradigm shifts capable of producing trajectories towards so-called 'climate justice'. This research analyses, through a holistic view, European policies in these fields, and delves into the actions and projects of four European cities - Amsterdam, Bilbao, Freiburg, and Lisbon - through a qualitative approach aimed at identifying strengths and contradictions of strategies to tackle the climate crisis. Delving into the collective dynamics and social impacts of the actions promoted, the research proposes a comprehensive view of the role that urban areas can play not only in decarbonising society, but in promoting a paradigm shift capable of addressing the economic causes and social consequences of the climate crisis.