University of Udine
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Inverse Problems for Nanostructures
No full textIn these lectures we review some recent results concerning inverse problems for thin elastic nanostructures. Nanostructures are assumed to be either one-dimensional (nanobeams) or two-dimensional (nanoplates), and are described within a simplified version of the strain gradient linear elasticity theory for isotropic materials. A first group of results concerns the use of nanobeams as mass-resonant sensors to identify an unknown added mass density by the measurement of a finite number of lower resonant frequencies. In the second group of results, we determine constructive upper and lower estimates of the area of an unknown elastic inclusion possibly present in a nanoplate given in terms of the work exerted by force and couple fields applied at the boundary of the nanoplate
The ECOLHE Erasmus + Project and the University to the Test of Digital Teaching and Learning: The Italian Case
No full textThe pandemic emergency has underscored the critical need for universities to accelerate their digital transformation to support proper teaching and learning processes. This paper presents findings from the Italian component of a broader international research project, which investigates the transformative impact of the digital revolution on Higher Education, under the umbrella of the Bologna Process, promoted by the European Community since 1999, to push the valorisation of Information and Communication Technologies to support the increasing needs of lifelong learning in the learning economy. The study posits that the mere availability of technological infrastructure is insufficient to ensure the effective integration of learning and knowledge technologies among faculty, students, and researchers. The Italian case reveals a complex landscape characterised by advancements and persistent challenges, indicative of a protracted and uneven digital integration process. But, overall, a strategic approach capable of showing a new vision and a systemic perspective to accompany this disruptive innovation is important
Thoracic electrical bioimpedance in preterm newborns with and without respiratory distress syndrome: an exploratory observational study
No full textTo test the hypothesis that thoracic fluid content (TFC) by thoracic electrical bioimpedance would be higher in preterm infants with respiratory distress syndrome (RDS) both at birth and in the first 48 h of life than in those without RDS and that TFC measured at birth would be associated with RDS diagnosis and need for surfactant. Cross-sectional exploratory observational study including infants ≤ 34 weeks of gestation admitted to two level three NICUs. TFC, clinical, and respiratory data were recorded at 5 timepoints: within the first 2 h of life, before surfactant therapy, and at 4, 12, 24, and 48 h of life. TFC was compared between infants with and without RDS. A ROC curve was calculated to assess the association between TFC at birth and the need for surfactant. TFC was higher in infants with RDS than in infants without RDS at all timepoints. The ROC AUC of TFC measured at birth for the need for surfactant was 0.817 (95% CI 0.64–0.93, p < 0.001); a TFC cut-off of 20.4 1/KOhm/Kg yielded a sensitivity of 83% and specificity of 80% for the need for surfactant. Conclusion: TFC in the first 48 h of life was higher in preterm infants with RDS than in infants without RDS. TFC measured within the first 2 h of life had a good association with the need for surfactant. (Table presented.
On the improvement of the combination of Power and Force Limiting and Speed and Separation Monitoring for an effective Human Robot Collaboration
Get PDFIn industrial human-robot collaborative tasks it is of paramount importance to guarantee safety, productivity and fluency. To this scope, beyond the two collaborative modalities introduced by the ISO/TS 15066 (Speed and Separation Monitoring - SSM and Power and Force Limiting - PFL), a modality that combines SSM and PFL to further enhance productivity of a collaborative task has been proposed in literature. However, such method, while guaranteeing an improvement with respect to the two modalities foreseen by the ISO/TS 15066, relies on some conservative assumptions that limit its potentialities. In this work, a method to overcome these limitations is presented and its effectiveness is validated through numerical simulations. Results show that the novelty introduced in this paper leads to an improvement in terms of productivity, fluency of the operation and in usage of the robot, without affecting the safety of the collaborative tasks
Introducing Code Quality at CS1 Level: Examples and Activities
Get PDFCharacterising code quality is a challenge that was addressed by a previous ITiCSE Working Group (Börstler et al., 2017). As emerged from that study, educators, developers, and students have different perceptions of the aspects involved. The perception of code quality by CS1 students develops from the feedback they receive when submitting practical work. As a consequence of increasingly large classes and the widespread use of autograders, student code is predominantly assessed based on functional correctness, emphasising a machine-oriented perspective with scarce or no feedback given about human-oriented aspects of code quality. Such limited perception of code quality may negatively impact how students understand, create, and interact with code artefacts. Although Börstler et al. concluded that "code quality should be discussed more thoroughly in educational programs", the lack of materials and time constraints have slowed down progress in that regard. The goal of this Working Group is to support CS1 instructors who want to introduce a broader perspective on code quality in their classroom, by providing a curated list of examples and activities suitable for novices. In order to achieve this goal, we have extracted from the CS education literature a range of examples and activities, which have then been analysed and organised in terms of code quality dimensions. We have also mapped the topics covered in those materials to existing taxonomies relevant to code quality in CS1. Based on this work, we provide: (1) a catalogue of examples that illustrates the range of quality defects that could be addressed at CS1 level; and (2) a sample set of activities devised to introduce code quality to CS1 students. These materials have the potential to help educators address the subject in more depth
The effects of gluten addition, dough moisture content and mixing time on the textural properties and in vitro starch digestibility of durum wheat bread made with coarse semolina
Get PDFThe production of bread using coarse semolina (CS), rich in intact cells, was hypothesized to be a good strategy for limiting starch accessibility. However, during long mixing, cell wall porosity increases and CS presence decreases bread cohesiveness, leading to high starch accessibility. To address this, the effect of water absorption level (WA, 70 or 55 %), mixing time (3.5 or 45 min), and the use of 100 % CS (> 1000 micrometer) or its 20 % substitution with gluten on the textural properties and in vitro digestibility of bread were studied. Bread made with 100 % CS at 55 % WA was the hardest, with low volume and less rapidly digestible starch (RDS). Gluten addition increased volume and porosity, leading to more RDS but reduced starch digestibility over time due to better structural integrity. These findings suggest that replacing 20 % of CS with gluten could be an effective strategy to decrease starch digestibility while maintaining a porous structure
High-Power Electrical Energy Conversion Systems for Industrial Production with Reduced Environmental Impact
No full textScientific consensus on anthropogenic climate change calls for drastic emissions reduction. Electrification is the cornerstone of this transition and needs backing by clean energy generation and modern grids. Both aspects rely on large-scale deployment of power converters and energy storage systems since the power quality and stability of traditional power systems are challenged by renewable energy sources’ non-dispatchable nature. Indeed, electrification’s growing energy demand drives a widespread need for high-power converter systems. At generation and distribution levels, converters actively control power flows and integrate storage to ensure power quality and resilience. High-power isolated converters (i.e., solid-state transformers, SSTs), supported by advanced control and communication, will constitute smart grids capable of supplying high power to, e.g., electric vehicles (EVs), datacenters, and high-power industrial loads. The rapid pace of deployment calls for careful attention to all aspects that can catalyze their series production and adoption.
In this context, the scope of this research project is to improve power converters in some of their aspects (e.g., efficiency, power density, material use, control performance) for lessening, either directly or indirectly, the environmental impact of the industry and transportation sectors, possibly by catalyzing new applications for an electrified economy. Towards this end, modularity is identified as a key feature, e.g., low-power power electronic building blocks (PEBBs) can be purposely combined to obtain a high-power system, enabling scalability, cost reduction, and increasing availability, with the drawback of increased complexity.
Prominent modular high-power converters, isolated and nonisolated, have been studied. In Part I, SSTs are discussed, also focusing on the conversion from medium-voltage AC (MVAC) to low-voltage DC (LVDC) as the most promising applications (e.g., for datacenters and fast EV charging). A modular SST has been investigated as derived from a recent patent that claimed hardware simplification. This work provided the first analyses on this new SST, greatly advancing its modeling, control, and high-level design, also providing a comparative evaluation against another SST and testing with refined simulations.
In SSTs, the isolation is provided by high-density transformers operating at increased frequencies that makes their design nontrivial. To contribute on this issue, this thesis studied a high-frequency transformer for a resonant CLLC converter working as a DC solid-state transformer (DCX), experimentally evaluating different winding configurations to explore the trade-off between electrical performance and ease of manufacturing.
In Part II, this work focuses on a prominent application for the heavy industry, proposing, motivating, and analyzing the application of the modular multilevel converter (MMC) to accelerate the deployment of next-generation electric arc furnaces (EAFs) for steelmaking with extended modularity than the state-of-the-art. A first feasibility study shows that the novel solution can match the existing one in power density but with improved modularity and scalability. Then, a novel control strategy tailored for this peculiar non-linear load (i.e., the electric arc) is provided and validated through advanced simulations, and a scaled-down prototype has been designed.
Several original scientific contributions have already been presented at the most relevant international conferences and have been the result of fruitful collaboration with national and international partners.
Ultimately, recognizing both the importance of innovation and industrial adoption, these findings pave the way for future research into SSTs and expanded MMC applications to ensure that power electronics remain at the forefront of the global transition toward cleaner and more resilient energy systems
Association of the Timing and Type of Acute Symptomatic Seizures With Poststroke Epilepsy and Mortality
No full textBACKGROUND: Acute symptomatic seizures (ASyS) increase the risk of epilepsy and mortality after a stroke. The impact of the timing and type of ASyS remains unclear. METHODS: This multicenter cohort study included data from 9 centers between 2002 and 2018, with a final analysis in February 2024. The study included 4552 adults (2005 female; median age, 73 years) with ischemic stroke and no seizure history. Seizures were classified using International League Against Epilepsy definitions. We examined ASyS occurring within seven days after stroke. The main outcomes were all-cause mortality and epilepsy. Validation of the updated SeLECT score (SeLECT-ASyS) was performed in 3 independent cohorts (Switzerland, Argentina, and Japan) collected between 2012 and 2024, including 74 adults with ASyS. RESULTS: The 10-year risk of poststroke epilepsy ranged from 41% to 94%, and mortality from 36% to 100%, depending on ASyS type and timing. ASyS on stroke onset day had a higher epilepsy risk (adjusted hazard ratio [aHR], 2.3 [95% CI, 1.3-4.0]; P=0.003) compared with later ASyS. Status epilepticus had the highest epilepsy risk (aHR, 9.6 [95% CI, 3.5-26.7]; P<0.001), followed by focal to bilateral tonic-clonic seizures (aHR, 3.4 [95% CI, 1.9-6.3]; P<0.001). Mortality was higher in those with ASyS presenting as focal to bilateral tonic-clonic seizures on day 0 (aHR, 2.8 [95% CI, 1.4-5.6]; P=0.004) and status epilepticus (aHR, 14.2 [95% CI, 3.5-58.8]; P<0.001). The updated SeLECT-ASyS model, available as an application, outperformed a previous model in the derivation cohort (concordance statistics, 0.68 versus 0.58; P=0.02) and in the validation cohort (0.70 versus 0.50; P=0.18). CONCLUSIONS: ASyS timing and type significantly affect epilepsy and mortality risk after stroke, improving epilepsy prediction and guiding patient counseling