Archivio della ricerca della Scuola Superiore Sant'Anna
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Breaking with Balance: Why Did Descartes Need Such a Complicated Image of the Lever?
No full textThe Treatise on Mechanics is a short essay by René Descartes (1596–1650) that deals with the so-called ‘simple machines’ of mechanics, which can be used to facilitate the lifting of heavy loads. It contains five hand-drawn images of such machines, which include the inclined plane, pulley, and lever. Descartes did not much care for the Treatise. He thought it was incomplete and generally unfit for publication. His contemporaries disagreed, however. Roughly thirty years after it was written, the treatise was published in brief succession in English, French, and Latin editions. Here, I assess the importance and novelty of the treatise with respect to the works contemporaneous readers would have compared it to: available treatises on the simple machines. We will look particularly at what these works tried to achieve, and how they went about their business. Although they do not seem to stand out at first sight, Descartes’s images have a number of particularities that set them apart from earlier works on the machines. I show that these particularities are bound up with a methodological choice by Descartes, namely his rejection of the convention of explaining the simple machines in terms of weights in equilibrium, and his introduction of the notion 'force'. At the end of this chapter. I address the paradoxical nature of Descartes’s force: on the one hand it is central to his mechanics, while on the other, it is strikingly absent in his images
Aage V. Jensen Foundation: un modello integrato per la conservazione della biodiversità e lo sviluppo sostenibile
No full textOn-device derivation of IoT usage control policies: Automating U-XACML policy generation from natural language with LLMs in smart homes environments
No full textIn this paper, we present a framework that integrates AI-based derivation of Access and Usage Control policies for IoT devices, using Large Language Models (LLMs) to automate the generation of policies from unstructured natural language commands. The framework employs a hybrid approach, combining LLMs with dedicated libraries to ensure efficient on-device execution. Our approach is based on a two-step process: first, a fine-tuned LLM converts user commands into structured JSON policy representations; then, a transformation module translates the JSON policies into fully compliant U-XACML policies. To ensure generality across different domains, we introduce a taxonomy-driven dataset creation, which enables policy creation for different environments such as smart homes, smart offices, and healthcare settings. Our evaluation demonstrates that the system achieves 93 % accuracy in policy generation and 91 % accuracy when handling ambiguous or noisy inputs. It also reaches 98 % agreement with expert-defined policies in real-world scenarios. Finally, on-device performance evaluations confirm the feasibility of running the model in practical settings, demonstrating reliable inference under constrained hardware conditions
Physiological and hormonal responses underlying salinity tolerance in wild tomatoes: Insights for cultivated varieties
No full textSoil salinisation is one of the main abiotic stress factors threatening modern agriculture, with over 1.3 million hectares affected worldwide and causing a progressive loss of arable land. Tomatoes are among the most important horticultural crops globally, but its moderate salt tolerance restricts productivity in saline soils. Related wild species, such as Solanum pimpinellifolium L., which have evolved in high-salinity environments, represent a valuable resource for studying adaptive stress responses and improving cultivated tomatoes. This study compares the salt stress response of S. lycopersicum L. and S. pimpinellifolium L. to identify the processes underlying the higher tolerance in wild species. Plants were grown hydroponically in a closed-loop system using two nutrient solutions: one mimicking seawater irrigation (33 % seawater, EC = 21 dS m−1), and a salt-free control (0 % seawater, EC = 3.22 dS m−1). Phenological, morphological, biochemical, physiological and hormonal traits were assessed. Solanum pimpinellifolium L. effectively modulates the production of osmolytes and photoprotective compounds, the translocation of toxic ions, and improves leaf function which, in synergy with a more integrated and temporally coordinated hormonal network that sustain better growth, yield, and fruit quality under saline conditions. These findings provide new insights into the physiological basis of salt tolerance in wild tomato, supporting its value as a genetic resource and suggesting that seawater-based irrigation may serve as a framework for studying sustainable water management strategies
In vivo efficacy of an injectable piezoelectric nanocomposite hydrogel and low-intensity pulsed ultrasound in two preclinical models of osteoarthritis
No full textSmart hydrogels embedding mesenchymal stromal cells are receiving increasing attention as a potential solution for preventing articular cartilage degeneration in knee osteoarthritis (OA). In this work we demonstrate that an injectable piezoelectric hydrogel embedding autologous adipose tissue-derived mesenchymal stromal cells (ASCs), stimulated by low-intensity pulsed ultrasound (LIPUS), is effective in reducing knee OA in two preclinical surgically induced OA models. A medium-sized rabbit model was used to evaluate sex differences in treatment efficacy, while a large-sized sheep model was employed to assess the translatability of this innovative approach to a scenario with similarities to human conditions. We developed computational models to ensure reliable and precise delivery of a specific ultrasound dose to the target, modelling wave propagation through tissues and considering the anatomy of the two experimental animal models. Sex-based differences in therapy effectiveness were observed in rabbits, with better macroscopic and microscopic outcomes in counteracting OA in female animals. Furthermore, we found that the combination of ASC-laden piezoelectric hydrogel and LIPUS can be scaled in a large-sized sheep model, proving effective in counteracting OA
External-field-assisted additive manufacturing for micro/nano device fabrication
No full textMicro/nano devices (MNDs) are characterized by miniaturization, high precision, and multifunctional integration, making them highly suitable for use in areas such as microrobotics, biomedical devices and electronic sensors. Their fabrication requires exceptional precision in structural integrity, material control, and functional integration. Traditional micro/nano fabrication techniques face inherent limitations in constructing complex three-dimensional (3D) architectures and integrating multiple materials. While additive manufacturing (AM) provides flexibility, challenges remain in material alignment control, microstructural organization, and multifunctional integration. To overcome these limitations, field-assisted additive manufacturing (FAM) has emerged as a promising approach that combines magnetic, acoustic, or electric fields to regulate material alignment, microstructural organization, and spatial alignment. This capability improves fabrication precision, enhances material anisotropy and facilitates functional integration. This review systematically explores the mechanisms, fabrication process, and functional integration of FAM in the framework of nozzle-based and vat photopolymerization-based, while further exploring their applications in microrobotics, biomedical devices, and electronic sensors. Moreover, this review provides a comparative overview of different FAM approaches, highlighting their respective characteristics, typical applications, and unique advantages. In addition, the major challenges facing FAM research are comprehensively assessed and future directions are explored, including advances in spatial precision control capability, intelligent control for process integration, and multi-field coupling optimization. This review establishes a foundational theoretical framework that can serve as a systematic reference for micro/nano manufacturing researchers to promote the development of FAM for high-performance micro/nano device fabrication
