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Analysis and numerical simulations of fractional order model of ring formation due to plant-soil negative feedback
No full textVegetation ring formation is a spatial pattern observed in ecosystems influenced by plant-soil negative feedback. Classical integer-order models capture only instantaneous interactions and cannot represent the history-dependent processes shaping these dynamics. To overcome this limitation, we propose a new time-fractional reaction-diffusion problem, that extends the model of Cartenì et al. of 2012 [1], by incorporating memory effects through Caputo derivatives. The system, consisting of coupled fractional partial differential equations (FPDEs) for biomass and toxicity, is analyzed for existence and uniqueness of solutions, equilibrium states, and stability in both homogeneous and heterogeneous cases. Since the analytical solution is not available, a numerical approach has been proposed. The numerical experiments illustrate variations in ring formation throughout time and space. The study covers multiple aspects, such as the influence of the fractional derivation index κ on pattern formation, showing that when κ decreases, the biomass spreads over a larger area with fewer oscillations and amplitudes. Moreover, reducing κ has the effect of slowing down the dynamics, requiring more time to reach the equilibrium points, and causes the ring’s width to expand, which shrinks the internal ring diameter until only disks are visible as κ tends to 0.6
Smart contract vulnerabilities, tools, and benchmarks: An updated systematic literature review
No full textSmart contracts are self-executing programs on blockchain platforms like Ethereum, which have revolutionized decentralized finance by enabling trustless transactions and the operation of decentralized applications. Despite their potential, the security of smart contracts remains a critical concern due to their immutability and transparency, which expose them to malicious actors. Numerous solutions for vulnerability detection have been proposed, but it is still unclear which one is the most effective. This paper presents a systematic literature review that explores vulnerabilities in Ethereum smart contracts, focusing on automated detection tools and benchmark evaluation. We reviewed 3380 studies from five digital libraries and five major software engineering conferences, applying a structured selection process that resulted in 222 high-quality studies. The key results include a hierarchical taxonomy of 192 vulnerabilities grouped into 13 categories, a comprehensive list of 219 detection tools with corresponding functionalities, methods, and code transformation techniques, a mapping between our taxonomy and the list of tools, and a collection of 133 benchmarks used for tool evaluation. We conclude with a discussion about the insights into the current state of Ethereum smart contract security and directions for future research
Surfactant-assisted hydrodistillation of Dictyopteris membranacea essential oil
No full textIn this work, surfactant-assisted hydrodistillation using the nonionic surfactant Triton X-100 is reported for the first time as an extraction strategy for essential oils (EOs) from the brown alga Dictyopteris membranacea , a species well known for its rich content of bioactive metabolites, including C11 hydrocarbons (sexual pheromones), sulfur-containing compounds, and terpenoids. A range of Triton X-100 concentrations was evaluated to optimize the extraction process, and the results were compared to conventional hydrodistillation, which yielded 0.12%. The extraction process exhibited three distinct phases: an initial increase in yield with rising surfactant concentration; a peak yield of 0.22% (w/w) observed at a Triton X-100 concentration of 8%–12% (v/v); and a subsequent decline at higher concentrations. EOs obtained under varying surfactant conditions were analyzed by GC-MS and GC-FID to assess the influence of Triton X-100 on their chemical profile. The results have extracting demonstrated a significant impact of surfactant
concentration on the relative abundance of major compound classes, notably C11 hydrocarbons, terpenes, and sulfur-containing compounds
Field-Effect Photodetectors Based on TMDCs: State of the Art and Future Trends
No full textIn the past two decades, two-dimensional (2D) materials, particularly transition metal dichalcogenides (TMDCs), have made a new way in the history of photonics and optoelectronics by making them promising candidates for future photodetectors with their controllable bandgap width, high charge carrier transport properties, and strong light-matter interaction. The realization of advanced device concepts are highly effected by various TMDCs with unique electronic and optical characteristics. Fast response time, high sensitivity, and wide spectral coverage are gained by harmonizing the architectural advantages of field-effect transistors with the high sensitivity inherent in 2D materials in TMDC-based field-effect transistors (TMDC-FETs). However, a number of drawbacks blocked their widespread use, such as high contact resistance, the presence of interface traps, high dark currents, and relatively low charge carrier mobility. In this review, recent developments in single-layer, heterostructure, and hybrid TMDC based FET photodetectors, with a particular focus on interface design, doping techniques, scalable manufacturing, and performance optimization are discussed
“Dopo i Fasci”. Nicola Barbato e l’internazionalismo anticoloniale di fin de siècle
No full texti Fasci dei lavoratori furono un movimento politico-sindacale di ispirazione socialista e democratica sviluppatosi in Sicilia tra il 1891 e il 1894. Si trattò di un’esperienza di mobilitazione collettiva che, per le dimensioni e i caratteri che assunse, non aveva precedenti e che fu quindi il primo movimento di massa nella storia d’Italia, diventando perciò uno dei principali modelli di riferimento nell’ambito della protesta sociale degli anni successivi. Per il loro rilievo e la loro complessità, a partire dal secondo dopoguerra essi sono diventati l’oggetto di una vasta letteratura storica, con la quale i contributi contenuti nel presente volume intendono fare i conti. L’obiettivo è quello di rilanciare la riflessione sui Fasci, che non possono essere letti soltanto come un fatto racchiuso all’interno dei confini dell’Isola, costituendo un punto di osservazione privilegiato da cui guardare gli esiti dirompenti delle grandi trasformazioni in atto nell’età contemporane
L'opera scientifica di Vincenzo Arangio-Ruiz. Presentazione dell'Edizione nazionale delle opere di Vincenzo Arangio-Ruiz (Roma, 30 maggio 2025)
No full textEnhancing Scientific Communication and Institutional Identity Through a Retrieval-Augmented Generation Digital Personal Tutor
No full textDibattito pubblico e maschilità: per un approccio critico e partecipativo al contrasto alla violenza di genere
No full textIl saggio si fonda sull’assunto che qualsiasi strategia di contrasto
alla violenza contro le donne risulti insufficiente se non accompagnata da interventi incisivi orientati a ridefinire gli atteggiamenti maschili e i processi di
socializzazione che li sostengono . La continuità delle configurazioni egemoniche della mascolinità, radicate in assetti patriarcali che si perpetuano attraverso pratiche culturali ordinarie
mette in luce il carattere strutturale
della questione.
Questa necessaria premessa teorica – che ha preso in esame il modo in cui la
maschilità trova spazio all’interno della costruzione del dibattito pubblico sul-
la violenza di genere, riconoscendo come molto raramente il maschile è coin-
volto come alleato del contrasto alla violenza di genere, previlegiando una co-
municazione che sofferma il suo sguardo principalmente sulla patologizzazio-
ne della violenza maschile sulle donne e sulle responsabilità individuali, senza
invece insistere sulla centralità delle azioni che devono trovare negli uomini il
loro principale destinatario – ci traghetta nella seconda parte di questo contri-
buto che, invece, prende in esame, attraverso la lente della cultura critica, i fat-
tori che favoriscono (e ostacolano) la partecipazione degli uomini al contrasto
alla violenza di genere, e le tipologie di azioni che possono essere intraprese a
tale scop
Generalized equilibrium distributions
No full textWe define the generalized equilibrium distribution, that is the equilibrium distribution of a random variable with support in . This concept allows us to prove a new probabilistic generalization of the Taylor's theorem. Then, the generalized equilibrium distribution of two ordered random variables is considered and a probabilistic analogue of the mean value theorem is proved. Results regarding distortion-based models and mean-median-mode relations are illustrated as well. Conditions for the unimodality of such distributions are obtained. We show that various stochastic orders and aging classes are preserved through the proposed equilibrium transformations. Further applications are provided in actuarial science, aiming to employ the new unimodal equilibrium distributions for some risks measures, such as Value-at-Risk and Conditional Tail Expectation