68 research outputs found
Design and characterization of a fractal-inspired multi-frequency piezoelectric energy converter
No full textA promising harvesting technique, in terms of simplicity and efficiency, is the conversion of ambient kinetic energy through piezoelectric materials. This work aims to design and investigate a piezoelectric converter conform to a fractal-inspired, multi-frequency structure previously presented by the author. A physical prototype of the converter is built and experimentally examined, up to 120 Hz, in terms of modal response and power output. Three eigenfrequencies are registered and the power output is particularly good at the fundamental eigenfrequency. Also the effect of the resistive load applied to the converter is investigated
Experimental Modal Analysis of Fractal-Inspired Multi-Frequency Piezoelectric Energy Converters
No full textAn important issue in the field of energy harvesting through piezoelectric materials is the design of simple and efficient structures which are multi-frequency in the ambient vibration range. This paper deals with the experimental assessment of four fractal-inspired multi-frequency structures for piezoelectric energy harvesting. These structures, thin plates of square shape, were proposed and numerically analyzed, with regard to their modal response, in a previous work by the author. The aim of this work is twofold. First, to assess the modal response of these structures through an experimental investigation. Second, to evaluate, through computational simulation, the performance of a piezoelectric converter prototype relying on one of these fractal-inspired structures. The four fractal-inspired structures are examined experimentally in the range between 0 and 100 Hz, both with regard to eigenfrequencies and eigenmodes. In the same frequency range are investigated the modal response and power output of a converter prototype
A fractal-inspired multi-frequency piezoelectric energy converter: computational and experimental characterization
No full textIn order to develop self-powered wireless sensor nodes, many energy harvesting devices, able to convert freely available ambient energy into electrical energy, have been proposed in the literature. A promising technique, in terms of simplicity and high conversion efficiency, is the harvesting of ambient kinetic energy through piezoelectric materials.The aim of this work is to design and investigate the modal response and the power output of a fractal-inspired, multi-frequency, piezoelectric energy converter, previously presented by the author. Two are the steps of the work. First, a computational modal analysis of the converter is performed. Second, a physical prototype of the converter is built and its eigenfrequencies and power generation under different resistive loads are experimentally examined in the range between 0 and 120 Hz. The converter exhibits three eigenfrequencies and a good power output, in particular at the first eigenfrequency
Tecnologie 3D e loro integrazione per la conoscenza e la rappresentazione dei beni culturali: il BIM di Santo Stefano a Bologna.
No full textL’attività di ricerca affronta il tema della documentazione, della rappresentazione e della conoscenza approfondita dello stato di fatto di complessi storici monumentali finalizzata alla loro tutela e conservazione. Il caso in esame è la Basilica di Santo Stefano a Bologna (BO), insieme di strutture modificatisi nel tempo e integratesi l’una con l’altra fino a creare l’attuale bellezza e allo stesso tempo l’attuale complessità strutturale. La necessità di conoscere in modo accurato e completo la geometria dello stato di fatto con tutte le variazioni architettonico/strutturali subite nel tempo è cruciale per coloro che sono deputati alla tutela e conservazione del bene con il fine di monitorare l’evoluzione del monumento, progettare interventi di consolidamento e restauro nonché programmare e gestire correttamente la manutenzione. L’approccio ritenuto più efficace per tutti questi scopi è la creazione di un modello geometrico BIM, Building Information Model, del bene storico (H-BIM) in cui confluiscono le informazioni di natura geometrica e morfologica ottenute dai rilievi mentre i dati di natura qualitativa sono stati inseriti in un database online su piattaforma web interpellabile. L’aspetto unico e innovativo ricade principalmente nella metodologia che vede l’integrazione di
molteplici tecnologie applicata alla straordinaria estensione e frammentarietà dell’intero complesso monumentale. Le attività, svolte nel 2012, hanno visto l’utilizzo di moderne tecniche di rilievo (laser scanning, livellazione di precisione, rilievo topografico e fotogrammetria da drone) e rappresentazione (modellazione BIM e restituzione grafica) nonché la creazione del primo esempio in Italia di H-BIM caratterizzato anche da tutte le anomalie geometriche tipiche di un edificio storico
INTEGRAZIONE DI TECNICHE GEODETICHE PER LA CONOSCENZA E LA GESTIONE DI COMPLESSI MONUMENTALI: L’HISTORICAL BIM DI SANTO STEFANO A BOLOGNA
No full textL’attività di ricerca affronta il tema della documentazione e della conoscenza approfondita dello stato di fatto di complessi storici monumentali finalizzata alla loro tutela e conservazione. Il caso in esame è la Basilica di Santo Stefano a Bologna (BO), conosciuta anche come “Complesso Delle Sette Chiese”, la quale rappresenta un complesso storico di edifici di culto di grande pregio con età che vanno dal V al XI secolo. Agli occhi dei tecnici, il complesso rappresenta un insieme di strutture modificatisi nel tempo e integratesi l’una con l’altra fino a creare l’attuale bellezza e allo stesso tempo l’attuale complessità strutturale. Considerando la prospettiva di coloro che sono deputati alla tutela e conservazione dei beni culturali, Santo Stefano esemplifica, quindi, molto bene la necessità di conoscere in modo accurato e completo la geometria dello stato di fatto con tutte le variazioni architettonico/strutturali che ha subito il complesso nel tempo con il fine di monitorare l’evoluzione del monumento, progettare interventi di consolidamento e restauro nonché programmare e gestire correttamente la manutenzione. L’approccio che fin da subito è stato ritenuto necessario ed efficace per tutti questi scopi è la creazione di un modello geometrico BIM, Building Information Model
Digital Twin & Blockchain: Technology Enablers for Metaverse Computing
No full textThe Metaverse has been recently envisioned as the next technological revolution with the idea of building fully immersive virtual worlds where users can interact with each other and with mixed-reality environments and objects. The relationship between the digital and the physical worlds represents a challenging opportunity to foster the idea that virtual experiences and interactions can complement and enhance reality enabling the definition of new use cases and services. In this context, Metaverse’s technologies need to rely on a connected, trustworthy, and highly detailed digital representation of users and objects to build an effective virtual world based on trusted and fresh information from the physical world. The need to decouple responsibilities through a multi-layered vision allows Metaverse’s applications to focus only on their business goal by relying on a cyber-physical layer enabling bi-directional communication with users and devices, accessing trusted information, invoking available actions, and retrieving immutable historical data. In this paper, we analyze and propose the combination of Digital Twins and Blockchain technologies as strategic pillars for bridging the gap between the virtual and the physical worlds and supporting the creation of the Metaverse
Vaginal and cervical anatomic modifications during the oestrus cycle in relation to transcervical catheterization in the domestic cat
No full textCritical issues and key points from the survey to the creation of the historical building information model: The case of Santo Stefano Basilica
No full textThe new era of designing in architecture and civil engineering applications lies in the Building Information Modeling (BIM) approach, based on a 3D geometric model including a 3D database. This is easier for new constructions whereas, when dealing with existing buildings, the creation of the BIM is based on the accurate knowledge of the as-built construction. Such a condition is allowed by a 3D survey, often carried out with laser scanning technology or modern photogrammetry, which are able to guarantee an adequate points cloud in terms of resolution and completeness by balancing both time consuming and costs with respect to the request of final accuracy. The BIM approach for existing buildings and even more for historical buildings is not yet a well known and deeply discussed process. There are still several choices to be addressed in the process from the survey to the model and critical issues to be discussed in the modeling step, particularly when dealing with unconventional elements such as deformed geometries or historical elements. The paper describes a comprehensive workflow that goes through the survey and the modeling, allowing to focus on critical issues and key points to obtain a reliable BIM of an existing monument. The case study employed to illustrate the workflow is the Basilica of St. Stefano in Bologna (Italy), a large monumental complex with great religious, historical and architectural assets
La modellizzazione dell'inquinamento atmosferico in aree urbane su scala locale: un esempio di applicazione in un quartiere di Torino
No full textDensification of IGS/EPN by local permanent networks: results sensitivity with respect to the adjustments choices
No full textThe paper describes the processing strategies experienced in dealing with GNSS permanent network. Particularly the choices for the adjustment of IGS and EPN network densification concerning the case of Puglia and Lombardia italian regions
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