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Reversed limes: Palermo Ringroad. Cataloguing the urban potential of neglected liminary spaces
No full textSince the second half of the 20th century, the theme of liminal or in-between spaces has attracted the recurring interest of many researchers in architecture. In contemporary European cities, liminal spaces have mainly emerged through the design of major infrastructures of the last century. They are usually linear in shape and are connected to or located along the urban edges of major highways.
The hypothesis we propose is that recycling heavy urban infrastructures can serve as a tool for the regeneration of contemporary cities, identifying their spaces as liminal urban places.
This catalogue refers to the Ringroad that surrounds the city of Palermo and recognises the potential of the empty liminal areas along the infrastructure as new public spaces. These areas — Perpignano, Giotto, and Lazio — are large, entirely public, and municipally owned. They suggest the layout of a true linear city, where the limen (door, entrance, passage) can be found through the limes (border, barrier).
The proposed design solutions include the removal of asphalt — replaced by piezoelectric paving — the addition of new trees and urban furniture to create shaded areas and mitigate perceived temperatures, and the construction of small, low-density pavilions to provide the surrounding neighbourhoods with multifunctional and multi-temporal facilities
Cooperative Interaction of Hyaluronic Acid with Epigallocatechin-3-O-gallate and Xanthohumol in Targeting the NF-κB Signaling Pathway in a Cellular Model of Rheumatoid Arthritis
Get PDFCurrent intra-articular therapies with hyaluronic acid (HA) provide symptomatic
relief in joint diseases, but have limited efficacy in counteracting oxidative stress and in-
flammation, key drivers of cartilage degradation in rheumatoid arthritis (RA). To address
this limitation, the potential of combining HA with the phytochemicals xanthohumol
(XAN) and epigallocatechin-3-O-gallate (EGCG), known for their antioxidant and anti-
inflammatory properties, was evaluated in a cellular model of RA (SW982 synoviocytes
stimulated with interleukin-1β, IL-1β). The Chou–Talalay method demonstrated that their
combination synergistically reduced reactive oxygen species (ROS) and nitric oxide (NO)
levels. The “TRIPLE” combination (HA + XAN + EGCG) showed the lowest combination
index and the highest dose reduction index. Compared to individual treatments, TRIPLE
significantly decreased IL-1β-induced IL-6, IL-8, TNF-α, and MMP-3 levels, while increas-
ing the levels of the anti-inflammatory cytokine IL-10. Western blot analysis revealed
a marked reduction in iNOS, COX-2, and MMP-3 protein expression following TRIPLE
treatment. Moreover, the combination inhibited IL-1β-induced phosphorylation of IκB and
p65, thereby preventing NF-κB activation. These findings suggest that integrating XAN
and EGCG into injectable HA formulations may represent a promising strategy to improve
the management of joint inflammation in RA
Valorizzazione dei sottoprodotti di Avocado (Persea Americana Mill. cv. Hass): attività antiossidante e caratterizzazione chimica mediante spettrometria di massa
No full textL'industria dell'avocado genera una notevole quantità di sottoprodotti, che costituiscono circa il 30% de peso totale del frutto e vengono spesso eliminati come scarti. Tuttavia, questi residui rappresentano una fonte preziosa di composti bioattivi con potenziali applicazioni nei settori alimentare, nutraceutico e cosmetico. La produzione mondiale di avocado ha raggiunto circa 8,98 milioni di tonnellate nel 2022. In
Italia, la coltivazione di avocado è in espansione, con la Sicilia che emerge come principale area di produzione. Questa crescita nella produzione siciliana offre opportunità economiche significative, soprattutto considerando il valore degli scarti di avocado, come semi e bucce, che possono essere riutilizzati per la produzione di bioenergia e altri utilizzi industriali, contribuendo così a un'economia più
sostenibile. L'obbiettivo di questo studio è stato caratterizzare le proprietà chimiche e funzionali dei sottoprodotti dell'avocado cv. Hass, in particolare semi e bucce, per valutarne il potenziale utilizzo nella produzione di alimenti fortificati. Su queste matrici, nel dettaglio, sono state effettuate analisi per la determinazione del contenuto totale di polifenoli (TPC) mediante il metodo Folin- Ciocalteu, espresso in
mg GAE/g, l'attività anti-radicalica espressa in mmol TEAC/100 g con i metodi DPPH e ABTS, il profilo degli acidi grassi determinato tramite GC-MS e il profilo dei composti fenolici analizzato mediante UHPLC-ESI/QTOF-MS.
Le bucce hanno mostrato eccezionali proprietà bioattive, con un contenuto totale di polifenoli pari a 386,80mg GAE/100g e un'attività antiossidante di 84,07 mmol TE/100g (DPPH) e 193,36 mmol TE/100g (ABTS), rispetto a valori inferiori registrati per i semi (80,65 mg GAE/100g e 40,51 mmol TE/100g, rispettivamente).
L'analisi del profilo degli acidi grassi mediante GC-MS, dopo estrazione della componente lipidica mediante Soxhlet, ha rivelato l'acido oleico come principale acido grasso, con una concentrazione di 19,751 mg/g nelle bucce e 29,101 mg/g nei semi. Inoltre, questa analisi ha evidenziato un elevato contenuto di acidi grassi totali nella buccia (23,77 g/100 g), con una distribuzione di 9,5% di SFA, 78,3%
di MUFA e 12,2% di PUFA. L'analisi UHPLC-ESI-MS [1] ha permesso di identificare nei campioni di bucce una significativa presenza di composti fenolici, tra cui l'acido caffeico (239,06 mg/100g) e l'acido clorogenico (391,42 mg/100g), insieme ad altre classi di composti bioattivi quali acidi idrossicinnamici, acidi idrossibenzoici,
flavonoidi, catechine, quercetine, proantocianidine e tannini. La valutazione microbiologica ha confermato l'assenza di microrganismi alteranti e patogeni, garantendo la sicurezza di bucce e semi per applicazioni alimentari.
Questi risultati hanno evidenziato il potenziale della valorizzazione dei sottoprodotti dell'avocado come ingredienti sostenibili e promotori di salute per l'industria alimentare e nutraceutica. Inoltre, l'integrazione
della farina di tali sottoprodotti nella produzione di alimenti funzionali, come pane e pasta, potrebbe rappresentare una soluzione innovativa per ottenere prodotti di alta qualità, nutrizionalmente ricchi e a basso costo, con ottime proprietà organolettiche. L'approccio adottato non solo contribuisce alla riduzione degli sprechi alimentari, ma promuove anche un impatto ambientale positivo attraverso la
generazione di biomassa riutilizzabile per la produzione di energia, con una ridotta emissione di inquinanti, allineandosi agli obiettivi globali di sostenibilità ambientale
Protective Effects of Extracts from Green Leaves and Rhizomes of Posidonia oceanica (L.) Delile on an In Vitro Model of the Human Blood–Brain Barrier
Get PDFPosidonia oceanica (L.) Delile, a Mediterranean seagrass, is rich in bioactive compounds with anti-inflammatory potential. While marine-derived molecules are increasingly studied, their direct effects on blood–brain barrier (BBB) integrity under inflammatory conditions remain largely unexplored. This study evaluated the ability of aqueous extracts from its green leaves (GLEs) and rhizomes (REs) to protect the BBB using a human in vitro model consisting of brain-like endothelial cells co-cultured with brain pericytes. The model was exposed to TNFα, with or without GLEs or REs. We assessed NO production, endothelial permeability, expression of IL-6, NLRP3, ICAM-1, VCAM-1, CLAUDIN-5, and VE-CADHERIN, and the localization of junctional proteins. TNFα increased NO and IL-6 release, upregulated ICAM-1, VCAM-1, and NLRP3, and impaired BBB integrity by altering junctional protein levels and distribution. Co-treatment with GLEs or REs reduced the production of NO, the expression of NLRP3 and adhesion molecules and restored tight and adherens junction integrity. IL-6 levels remained unaffected. These findings suggest that P. oceanica’s extracts may help preserve BBB function and mitigate inflammation-induced damage. While further studies are needed to assess their bioavailability and in vivo efficacy, these natural compounds represent promising candidates for developing preventive strategies against neuroinflammatory disorders
W[oa]ndering Medina
Get PDFW[oa]ndering Medina is a visitor center that embraces and highlights the dynamics of mutual exchange between the UNESCO site “Medina of Marrakesh” and its visitors – or rather, all users of the urban space, including residents and those that have the opportunity to pass through it.
The very name of the center – W[oa]ndering Medina – stems from an undeniable and defining characteristic of the Medina: its labyrinthine layout, which inevitably leads every visitor to lose and find their way over and over again. This name references the two fundamental actions essential to experiencing the Medina: wandering, the act of roaming through its intricate fabric, and wondering, the sense of awe in discovering its beauty, revealed step by step. To make these two actions explicit, the project is based on an in-depth reading of the site, its urban fabric, the relationships that shape it, and its multiple identities – ranging from an imperial city to a Berber trade hub and even an exotic destination for the cultural elite of fashion and design – and on the incorporation of the objectives defined by UNESCO for visitor centers in World Heritage Sites (UNESCO, The Role of Visitor Centres in UNESCO Designated Sites, 2019).The proposal is structured around two key components: an urban project, offering a comprehensive vision and experience of the Medina; the design of the visitor center within El Badi Palace, which serves as the official visitor center for the UNESCO site. In this sense, the W[oa] ndering Medina visitor center is not conceived as a centralized hub, nor as a starting or ending point, but rather as a strategic and highly sensitive node within a vast and intricate network – one that, in all its complexity and potential, encompasses the entire UNESCO site.
Layout of the urban project
Certain elements of the Medina’s fabric – recognized as both structural and structuring in its general composition, as well as fundamental to the experience within it – serve as the foundation for an urban project designed around key moments of the visit. At these designated points, several devices are placed which, when applied to various urban surfaces – both vertical and horizontal – serve as elements of orientation and understanding of the place. In particular, the system of walls and gates, which form the first point of contact between the Medina and its users, marks the moment of entry, where each threshold becomes the starting point (incipit) of a journey.
Once inside, the Medina’s dense and intricate pattern, in which visitors find themselves immersed (and, to some extent, disoriented), defines the moment of exploration where a network of paths and narrative threads guides visitors through the city, encouraging them to get lost and find their way again, following a coordinated graphic and communicative strategy.
Within the urban fabric, encounters with a network of points of interest – riads, gardens, monuments – shape the moment of discovery, where each designated site offers a deeper understanding of a specific aspect or reality of the Medina. Finally, major landmarks – such as Jemaa el-Fnaa square, as well as the visitor center located within El Badi Palace – define the moment of knowledge, where the most profound and complete unveiling of the Medina and its meanings takes place. For the implementation of UNESCO objectives
The W[oa]ndering Medina proposal – both in its urban project and in the visitor center at El Badi Palace – aligns with the key areas of interest outlined in the report The role of Visitor Centres in UNESCO Designated Sites (UNESCO, 2019). It introduces a new formal expressiveness to the context, connects previously isolated areas, and enhances the visibility and accessibility of the site’s unique qualities. The project focuses on some main core goals regarding different stakeholders, taking the possible ways of using the sites as main stimulus: from the ordinary tourist visit, aimed at didactically and directly investigating the history of the heritage, to the specialised visit of the targeted researcher or architect, to the continuous living experience of members of the local community. The main functions of the project focuses on tourism sustainability and visitors’ management, interpretation of heritage, educational services, community engagement and community-oriented services. In particular, project activities are divided into three macro-categories.
Information: the reopening of the courtyard adjacent to the El Badi Palace and the overall design of the project allow for the reinterpretation and understanding of the original form of the palace, formed by long porticoed paths and pavilions defined a strong axiality in the overall; design furthermore, the particular shading systems proposed allow for direct reference to the intangible heritage of local traditions and Moroccan handicrafts, as a tool for empowering local identity.
Education: the structural system used has a double value with respect to the issue of sustainability and social impact. On the one hand, the proposed structure consists of a system of dry, modular and reversible joints that do not permanently affect the existing heritage; on the other, the formal result, constituting at first glance a static reinforcement structure, already installed following the 2023 earthquake, draws attention to the fragility of the urban fabric and heritage itself; however, once the emergency phase has passed, the same structures define spaces spread throughout the city for social aggregation and sharing, including through workshop or debate activities hosted in urban spaces or in the pavilion spaces within the El Badi Palace.
Accessibility: the project addresses the issue of spatial fruition not only through the design of fully accessible and walkable spaces, but also through the design of spaces where there is full freedom to stop and rest to enjoy the visit, spaces where one can stop and reflect, spaces where it is possible to set up temporary exhibitions in full functionality and usability.
Highlights for a sustainable tourism
The project W[oa]ndering Medina incorporates elements of modularity and mobility, both in time and space, with the goal of seamlessly integrating into the existing dynamics of the Medina. Working within an urban UNESCO site requires addressing the challenge of balancing the inhabited, everyday dimension with the tourism-driven, exceptional, dimension. Both are fundamental to the identity of this World Heritage site, yet they can also come into conflict, particularly in cases of overtourism, which can compromise its proper enjoyment and preservation.
With this in mind, the project is designed to be flexible over time, allowing different components to be implemented and activated at different moments to test the response of the city and its inhabitants. More broadly, W[oa]ndering Medina also plays a role in reshaping how tourists experience the city, acting as a tool to calibrate, guide, and distribute visitors across multiple itineraries, helping to prevent potential overcrowding. Rather than concentrating activity in a single location, the proposal engages multiple sites, encouraging visitors to move continuously throughout the entire area – from the outer edges to the core of the Medina and vice versa. Expanding the visitor experience beyond just the main attractions promotes a form of sustainable and culturally rich tourism, one that not only provides essential resources for the site and those who care for it daily but also ensures that it is neither exploited nor damaged. Instead, the project fosters an authentic and respectful engagement with the site’s heritage and value.
The visitor centre at El Badi Palace
El Badi Palace plays a particularly significant role in the experience of the Medina, both as one of its most renowned attractions and as a key access point to the city and a vast network of green spaces to the south (the Jardins d’Agdal).
The visitor center is composed of multiple elements, strategically positioned at different points within the archaeological site. Some interventions establish a direct continuity with the ruins, particularly around the current entrance, the eastern wall, and the remains of the pavilion in that area. As part of an effort to enhance the site, certain spaces are redefined in terms of volume and spatial perception through the use of lightweight wooden structures, fabric draperies, and decorative ceramic elements. These designed yet dematerialized spaces are primarily intended for welcoming visitors who wish to enter the archaeological site directly, without passing through the other sections of the visitor center. Additionally, some palace areas are repurposed for museographic use, effectively exhibiting themselves as part of the visitor experience.
For the implementation of UNESCO objectives
The W[oa]ndering Medina proposal – both in its urban project and in the visitor center at El Badi Palace – aligns with the key areas of interest outlined in the report The role of Visitor Centres in UNESCO Designated Sites (UNESCO, 2019). It introduces a new formal expressiveness to the context, connects previously isolated areas, and enhances the visibility and accessibility of the site’s unique qualities. The project focuses on some main core goals regarding different stakeholders, taking the possible ways of using the sites as main stimulus: from the ordinary tourist visit, aimed at didactically and directly investigating the history of the heritage, to the specialised visit of the targeted researcher or architect, to the continuous living experience of members of the local community. The main functions of the project focuses on tourism sustainability and visitors’ management, interpretation of heritage, educational services, community engagement and community-oriented services. In particular, project activities are divided into three macro-categories.
Information: the reopening of the courtyard adjacent to the El Badi Palace and the overall design of the project allow for the reinterpretation and understanding of the original form of the palace, formed by long porticoed paths and pavilions defined a strong axiality in the overall; design furthermore, the particular shading systems proposed allow for direct reference to the intangible heritage of local traditions and Moroccan handicrafts, as a tool for empowering local identity.
Education: the structural system used has a double value with respect to the issue of sustainability and social impact. On the one hand, the proposed structure consists of a system of dry, modular and reversible joints that do not permanently affect the existing heritage; on the other, the formal result, constituting at first glance a static reinforcement structure, already installed following the 2023 earthquake, draws attention to the fragility of the urban fabric and heritage itself; however, once the emergency phase has passed, the same structures define spaces spread throughout the city for social aggregation and sharing, including through workshop or debate activities hosted in urban spaces or in the pavilion spaces within the El Badi Palace.
Accessibility: the project addresses the issue of spatial fruition not only through the design of fully accessible and walkable spaces, but also through the design of spaces where there is full freedom to stop and rest to enjoy the visit, spaces where one can stop and reflect, spaces where it is possible to set up temporary exhibitions in full functionality and usability.
Highlights for a sustainable tourism
The project W[oa]ndering Medina incorporates elements of modularity and mobility, both in time and space, with the goal of seamlessly integrating into the existing dynamics of the Medina. Working within an urban UNESCO site requires addressing the challenge of balancing the inhabited, everyday dimension with the tourism-driven, exceptional, dimension. Both are fundamental to the identity of this World Heritage site, yet they can also come into conflict, particularly in cases of overtourism, which can compromise its proper enjoyment and preservation.
With this in mind, the project is designed to be flexible over time, allowing different components to be implemented and activated at different moments to test the response of the city and its inhabitants. More broadly, W[oa]ndering Medina also plays a role in reshaping how tourists experience the city, acting as a tool to calibrate, guide, and distribute visitors across multiple itineraries, helping to prevent potential overcrowding.
The main core of the visitor center is located within a currently inaccessible and unused quadrangular area along the eastern side of the palace. Conceived as an “urban void” within a dense, saturated fabric, this space presents a valuable opportunity to design a new building for visitors, while also providing a solution for an unresolved urban area – despite its direct continuity with the archaeological site. In this section, the visitor center takes the form of a courtyard, reinterpreting and reintroducing some of the defining characteristics of this local architectural typology (riad). A portico runs along all four sides, expanding on the eastern side, where the main functions of the visitor center are housed, along with the large central hall. This hall, directly accessible from the exterior, is flooded with natural light from above and features a central water element, referencing the traditional and local use of ablution pools. The composition of volumes, together with the design of the vegetation and water basins in the garden, defines the main circulation axis, linking the new courtyard (the visitor centre) to the historic one (within El Badi Palace). Alongside vegetation and water – essential elements of the riad – the materials used include stone for the walls and portico columns, ceramic for flooring and select cladding, and wood and metal for the roofing, treated as mashrabiya, once again drawing from local traditions
MRI-based prediction of the need for wide resection margins in patients with single hepatocellular carcinoma
Get PDFObjectives: To develop an MRI-based score that enables individualized predictions of the survival benefit of wide over narrow resection margins. Materials and methods: This single-center retrospective study (December 2011 to May 2022) included consecutive patients who underwent curative-intent resection for single Barcelona Clinic Liver Cancer (BCLC) 0/A HCC and preoperative contrast-enhanced MRI. In patients with narrow resection margins, preoperative demographic, laboratory, and MRI variables independently associated with early recurrence-free survival (RFS) were identified using Cox regression analyses, which were employed to develop a predictive score (named “MARGIN”). Survival outcomes were compared between wide and narrow resection margins in a propensity-score matched cohort for the score-stratified low- and high-risk groups, respectively. Results: Four hundred nineteen patients (median age, 54 years; 361 men) were included, 282 (67.3%) undergoing narrow resection margins. In patients with narrow resection margins, age, alpha-fetoprotein (AFP) > 400 ng/mL, protein induced by vitamin K absence or antagonist-II (PIVKA-II) > 200 mAU/mL, radiological involvement of liver capsule, and infiltrative appearance were associated with early RFS (p values, 0.002–0.04) and formed the MARGIN score with a testing dataset C-index of 0.75 (95% CI: 0.65–0.84). In the matched cohort, wide resection margin was associated with improved early RFS rate for the high-risk group (MARGIN score ≥ − 1.3; 71.1% vs 41.0%; p = 0.02), but not for the low-risk group (MARGIN score < − 1.3; 79.7% vs 76.1%; p = 0.36). Conclusion: In patients with single BCLC 0/A HCC, the MARGIN score may serve as promising decision-making to indicate the need for wide resection margins. Clinical relevance statement: The MARGIN score has the potential to identify patients who would benefit more from wide resection margins than narrow resection margins, improving the postoperative survival of patients with single BCLC 0/A hepatocellular carcinoma (HCC). Key Points: Age, AFP, PIVKA-II, radiological involvement of liver capsule, and infiltrative appearance were associated with early RFS and formed the MARGIN score. The MARGIN score achieved a testing dataset C-index of 0.75. Wide resection margins were associated with improved early RFS for the high-risk group, but not for the low-risk group. Graphical Abstract: (Figure presented.
Managing Concept Drift in Online Intrusion Detection Systems with Active Learning
Get PDFMachine learning-based Intrusion Detection Systems (IDS) are widely used to identify and mitigate threats by analyzing network traffic for malicious activity. However, most existing IDS solutions assume a closed environment with stable statistical properties. This overlooks challenges posed by open environments and the problem of concept drift, where shifts in network traffic patterns over time can render training data obsolete and degrade the performance of static systems. While online IDS can adapt to these changes, they face the additional challenge of acquiring labeled data in real time, which is often impractical due to time constraints. To address these challenges, this paper proposes an online IDS that employs an incremental supervised Random Forest model combined with a drift-aware approach, designed for open environments with limited labeling. Active learning techniques are used to select the most informative records, minimizing the need for human feedback while retaining enough information to detect drifts. The system adapts incrementally when drift is detected, updating the underlying model as needed. The experimental evaluation, performed on a real-world network dataset, proves the system’s effectiveness in open environments and under limited labeling conditions, achieving better performance compared to state-of-the-art methods
An Advanced Hexacopter for Autonomous Exploration of Mars: Attitude Control and Navigation Strategies
Get PDFL'esplorazione di Marte ha recentemente suscitato un forte interesse all'interno della comunità scientifica. Le piattaforme robotiche senza equipaggio offrono soluzioni affidabili per acquisire e raccogliere dati e informazioni dal Pianeta Rosso. In particolare, rover, lander e orbiter hanno avuto un ruolo determinante nell’esplorazione planetaria della Luna e di Marte, contribuendo in modo significativo alle missioni passate, ma allo stesso tempo evidenziando i limiti nella capacità di coprire terreni eterogenei su ampie aree. Considerando i recenti progressi nei Sistemi Aeromobili a Pilotaggio Remoto (UAS), i Veicoli Aerei Senza Equipaggio (UAV) rappresentano alternative promettenti per le future missioni scientifiche.Si ritiene che gli esacotteri, grazie al loro design relativamente compatto e alla ridondanza, costituiscano una soluzione promettente per compiti di esplorazione autonoma su Marte, superando i limiti dei rover su ruote e migliorando la risoluzione dei dati acquisiti dagli orbiter.Tuttavia, le condizioni ambientali particolarmente ostili del pianeta Marte comportano un inviluppo di volo ristretto nelle fasi di volo vicino alla superficie e di atterraggio. A tal fine, sono necessarie strategie di navigazione autonoma e controllori robusti per affrontare compiti esplorativi complessi.Questa ricerca si concentra sulla progettazione di un Esacottero Marziano (MHex) per una missione di ricognizione nella regione marziana di Jezero. La configurazione e l’architettura dell’esacottero prendono come riferimento iniziale lo studio concettuale della NASA sul Mars Science Helicopter (MSH). Successivamente, viene analizzato il profilo della missione per la mappatura del cratere Belva, seguito da un approccio dettagliato per implementare e testare strategie autonome di navigazione e controllo basate su osservatori. Viene inoltre presentato un ambiente simulato completo, basato sull’integrazione di ROS e Ardupilot, utilizzato per validare l’architettura complessiva del sistema e i parametri della missione, considerando sia la morfologia del cratere esplorato sia le condizioni atmosferiche marziane.Mars exploration has recently witnessed major interest within the scientific community. Unmanned robotic platforms offer reliable solutions to acquire and collect data and information from the Red Planet. Particularly, rovers, landers, and orbiters have significantly shaped planetary exploration on the Moon and Mars, contributing significantly to past missions while also highlighting limitations in their capacity to cover diverse terrains over wide ranges. Given current advances in Unmanned Aircraft Systems (UASs), Unmanned Aerial Vehicles (UAVs) offer promising alternatives for future scientific missions.It is argued that hexacopters, with their relatively compact design and redundancy, present a promising solution for autonomous exploration tasks on Mars, overcoming at the same time the limitations of wheel-based rovers and increasing orbiters' data resolution. However, the specific harsh conditions of the Martian environment result in a restricted flight envelope when flying close to the surface and then landing. To this end, autonomous navigation strategies along with robust controllers are needed for complex exploration tasks.This research focuses on designing a Mars Hexacopter (MHex) for a scouting mission in the Martian Jezero region. The hexacopter configuration and architecture considers, as a initial baseline, the NASA conceptual study of the Mars Science Helicopter (MSH). Then, the mission profile for mapping the Belva crater is examined, followed by a detailed approach to implement and test autonomous observer-based navigation and control strategies. A comprehensive simulated environment is also presented based on integrating ROS and Ardupilot, which is used to validate the overall system architecture and the mission parameters considering both the morphological shape of the explored crater and the atmospheric conditions of Mars
An Arbitrary Order Virtual Element Method for Free Torsional Vibrations of Beams
Get PDFIn this study, a novel arbitrary order Virtual Element Method (p-VEM) for free torsional
vibration analysis of beams with negligible warping is presented. This method can serve
as an equivalent beam model for slender aerospace structural components. The proposed
formulation utilizes a spatial discretization of the primary variable with implicit virtual
functions that are approximated with polynomials of arbitrary order p by employing a
suitably defined projection operator and degrees of freedom. From the spatial discretization
of the weak form of the equations of motion, the semi-discrete equations of motion are obtained,
from which stiffness and mass matrices are derived without the need for additional
stabilization. The developed formulation is validated through several case studies, which
demonstrate that the p-VEM offers higher accuracy and faster convergence rate compared
to traditional modeling approaches