Development and experimental validation of a Sense-and-Avoid System for a mini-UAV

This paper provides an overview of the three-year effort to design and implement a prototypical sense-and-avoid (SAA) system based on a multisensory architecture leveraging data fusion between optical and radar sensors. The work was carried out within the context of the Italian research project named TERSA (electrical and radar technologies for remotely piloted aircraft systems) undertaken by the University of Pisa in collaboration with its industrial partners, aimed at the design and development of a series of innovative technologies for remotely piloted aircraft systems of small scale (MTOW < 25 Kgf). The system leverages advanced computer vision algorithms and an extended Kalman filter to enhance obstacle detection and tracking capabilities. The “Sense” module processes environmental data through a radar and an electro-optical sensor, while the “Avoid” module utilizes efficient geometric algorithms for collision prediction and evasive maneuver computation. A novel hardware-in-the-loop (HIL) simulation environment was developed and used for validation, enabling the evaluation of closed-loop real-time interaction between the “Sense” and “Avoid” subsystems. Extensive numerical simulations and a flight test campaign demonstrate the system’s effectiveness in real-time detection and the avoidance of non-cooperative obstacles, ensuring compliance with UAV aero-mechanical and safety constraints in terms of minimum separation requirements. The novelty of this research lies in (1) the design of an innovative and efficient visual processing pipeline tailored for SWaP-constrained mini-UAVs, (2) the formulation an EKF-based data fusion strategy integrating optical data with a custom-built Doppler radar, and (3) the development of a unique HIL simulation environment with realistic scenery generation for comprehensive system evaluation. The findings underscore the potential for deploying such advanced SAA systems in tactical UAV operations, significantly contributing to the safety of flight in non-segregated airspaces

Battery energy storage systems for ancillary services in renewable energy communities

Renewable Energy Communities can become relevant flexibility actors thanks to their capability of gathering under the same ecosystem, different energy assets, such as generation, and storage, and deferrable and controllable devices such as heavy appliances and computing assets. Particularly thanks to the integration of different energy storages RECs can therefore become a relevant grid operator. This document presents a review of storage and flexibility services alongside a quantitative methodology to analyze its benefits, using the Julia-based EnergyCommunity.jl package. The renewable energy community in Savona in collaboration with the University of Genova campus has been simulated to assert the battery energy storage systems potential. The study compares the outcomes of cooperative approaches with and without flexibility services to a scenario where users do not cooperate. The study concludes that storage systems can create new flexible instruments for the grid and a tool for citizens, which could make batteries financially viable. The study suggests that greater transparency and information on hourly energy sales and purchase prices would facilitate awareness among community members and stimulate discussion of technologies such as batteries to cover the most expensive nighttime periods for users

Self-Deployable pulsating heat pipe concept based on a shape memory alloy actuator

The concept of a self-deployable Pulsating Heat Pipe (PHP) actuated by Shape Memory Alloy (SMA) is shown in the present paper. The system exploits the heat source to activate both the two-phase flow in the PHP and the shape memory effect in the actuator to passively fold and unfold the device. The PHP acts as a torsional spring in the adiabatic section, and a shape memory wire unfolds it. The authors propose a mechanical model that outlines the size/material (spring/Al6063) and number of coils (3.5) to design the PHP adiabatic section and the actuator (7 Nickel-Titanium parallel wires). Two strategies are adopted to simulate active (Joule effect) and passive (heat conduction) heating. Joule heating uniformly warms the SMA wire to 120 °C, allowing the device to deploy up to 80 deg. Despite, under the passive heating, the shape memory effect is limited (deployment 16.5 deg) due to poor heat conduction, this is a breakthrough starting point for further implementation. For such purpose, the shape memory effect at non-uniform heating is simulated and predicted via a thermomechanical analytical model. Simulations are then validated with good accuracy with the experimental results obtained (error between 12 %-15 %)

Analysis of BEPU-Approached Multi-Physics Wall-to-Fluid Single Phase Friction Pressure Drop

Over the last few decades, the aim in Nuclear Reactor Safety (NRS) research and licensing has been to transition from conservative model use, which was widely used in the early stages of the nuclear industry, to the Best Estimate Plus Uncertainty (BEPU) approach in order to increase the accuracy of results to increase reactor output power safely. Furthermore, this decision is made to cover the increase in complexity of physics (i.e. Natural Circulation (NC), Passive Safety Systems) used in nuclear reactors, despite a reduction in the number of active mechanical parts. The central pillars of BEPU which are the selection of realistic Boundary and Initial Conditions (BIC) along with the adoption of an accurate model implemented in the Best Estimate (BE) System Thermal-hydraulic (SYS TH) Code, and uncertainty quantification methodologies should provide the reference for future works. Among the 116 Thermal-Hydraulic Phenomena (THP) for Water Cooled Nuclear Reactors (WCNRs) that are unique within the studied range of variables, the wall-to-fluid friction pressure drop (PD) as a Basic Phenomenon (BP) that can have a severe impact on the overall behavior of a thermal-hydraulic (TH) system. In fact, in normal operation conditions of NC systems, the efficiency of heat removal in the primary system is strongly dependent on PDs whereas, in off-normal scenarios, meeting Emergency Core Cooling System (ECCS) criteria may be subject to the influence of PDs along injection lines. Furthermore, this THP has an empirical origin, meaning there exists an integration domain in friction PD explicit formulas based on Re number and relative roughness, while some geometries used in Nuclear Power Proceedings of the 14th International Conference of the Croatian Nuclear Society Zadar, Croatia, June 9 – 12, 2024 Paper No. 120 SESSION X: Title of Session X (To be added by Programme Committee) Plants (NPP) may not fulfill the requirements of this integration domain. One of the main sources of uncertainty in friction factor calculations is the selection of an appropriate value for absolute roughness. The selection of the right value for roughness can become difficult because of the possible evolution of the surface of the hydraulic component concerning time. Indeed, the initial surface condition of the alloys can evolve on contact with the cooling solutions, by the growth of corrosion products, or by the deposition of particles resulting from this corrosion. Thus, roughness can change both with aging also based on different stages in subsequent time windows, and choosing a range for absolute roughness is suggested. This work's ultimate goal is to assess the possible errors in both RELAP Mod3.2mz and RELAP-3D as candidates for the most used BE SYS TH codes in Thermal-Hydraulic analysis and to emphasize the selection of the most appropriate model for wall-to-fluid friction factor. To do so, research focused on the results obtained in single-phase PDs using subcooled water with realistic BICs, since the correlations used for single-phase calculations are fairly well developed, and enough experimental data are available. In order to use the results obtained from codes in the nuclear industry, V&V&C must be applied in core-related safety issues, as it must be able to show the capability of computational tools with a demonstration of an error. As stated, wall-to-fluid friction PDs, must not be treated as low-level objectives anymore, especially for the design of RCS that rely on NC or passive systems. In addition, wall-to-fluid friction PD must be considered as a Multi-Physical BP, since both water chemistry and wall material, as representative of coolant chemistry and material, all affect the PDs

“Julio Vélez Sainz, Clásicos subversivos / clásicos subvertidos. Apropiación y vigencia del teatro áureo, Reichenberger, Kassel, 2023, 332 pp.”

Recensione della monografia di Julio Vélez Sainz dedicata alla diffusione del patrimonio teatrale classico spagnolo, in particolare nei secoli XIX e XX

Synthesis and biological investigation of peptidomimetic SARS-CoV-2 main protease inhibitors bearing quinoline-based heterocycles at P3

In the last few years, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been the cause of a worldwide pandemic, highlighting the need for novel antiviral agents. The main protease (Mpro) of SARS-CoV-2 was immediately identified as a crucial enzyme for viral replication and has been validated as a drug target. Here, we present the design and synthesis of peptidomimetic Mpro covalent inhibitors characterized by quinoline-based P3 moieties. Structure–activity relationships (SARs) were also investigated at P1 and P2, as well as for different warheads. The binding modes of the designed inhibitors were assessed using X-ray crystallographic and molecular docking studies. The identified Mpro inhibitors were tested for their antiviral activities in cell-based assays, and the results were encouraging. The SAR studies presented here can contribute to the future design of improved inhibitors by addressing some of the current or prospective issues regarding Mpro inhibitors currently used in therapy