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Experimental study and gyrokinetic simulations of isotope effects on core heat transport in JET tokamak deuterium and tritium plasmas
No full textThis paper presents a study on the dependence of the ion temperature stiffness on the plasma main ion isotope mass in JET ITER-like wall and C wall discharges. To this aim, a database of H, D and T shots is analyzed, including new dedicated shots, comparing experiments with lower and higher power injected by the NBI system. In order to characterize the turbulence dependence on the isotope mass, three of these discharges (two in T and one in D) with same external heating scheme are studied in detail and interpreted with gyrokinetic linear and nonlinear simulations. The analysis is performed at fixed radius ρ tor = 0.33 , selected in order to maximize the electromagnetic stabilizing effects on turbulence, both from thermal and suprathermal particles. The experimental results show a clear ion temperature stiffness reduction when heavier isotopes are considered, thus moving from H to D to T, which is attributed to an increasing thermal electromagnetic stabilization with increasing main isotope mass
Heat-Flux Relaxation and the Possibility of Spatial Interactions in Higher-Grade Materials
No full textWe investigate the thermodynamic compatibility of weakly nonlocal materials
with constitutive equations depending on the third spatial gradient of the deformation and the heat flux ruled by an independent balance law. In such materials, the molecules experience long-range interactions. Examples of biological systems undergoing nonlocal interactions are given. Under the hypothesis of weak nonlocality (constitutive equations
depending on the gradients of the unknown fields), we exploit the second law of thermodynamics by considering the spatial differential consequences (gradients) of the balance laws as additional equations to be substituted into the entropy inequality, up to the order of the gradients entering the state space. As a consequence of such a procedure, we obtain
generalized constitutive laws for the stress tensor and the specific entropy, as well as new forms of the balance equations. Such equations are, in general, parabolic, although hyperbolic situations are also possible. For small deformations of homogeneous and isotropic bodies, under the validity of a generalized Maxwell–Cattaneo equation for the heat flux,
which depends on the deformation too, we study the propagation of small-amplitude thermomechanical waves, proving that mechanical, thermal and thermomechanical waves are possible
Scientific response to the 2021–2022 seismic swarm in the Monts Dore volcanic province (France): dynamic insights from temporal surveys (2/2)
Get PDFDuring years 2021–2022, an unusual seismic swarm was recorded at crustal level beneath
the Monts Dore volcanic province (France). Complementary field and remote measurements were
performed. Together with the time series recorded on the seismological and GNSS national networks,
these measurements were fundamental for monitoring the evolution of the seismic swarm and deciphering
its origin. Although a potential vertical migration of the seismic events is suggested, the complementary
measurements presumably discard the hypothesis of magma intrusion at shallow crustal
level. The ascent of a CO2-rich fluid originating from the mantle might instead have reacted with the
hydrothermal system beneath the Monts-Dore since at least the summer 2021 leading to the reactivation
of pre-existing tectonic structures with known associated seismicity. Feedback on themanagement
of the 2021–2022 seismic swarm prompts for several recommendations that should be considered
in future to better face and address at the national level the issues raised at long-dormant volcanic
provinces inmainland France
Sostenibilità e competitività aziendale: analisi economica di una innovazione per il miglioramento della shelf life dei prodotti ortofrutticoli
Get PDFLo spreco alimentare è uno tra i temi più dibattuti dell’ultimo decennio e rappresenta una priorità dell’agenda politica di tutti i Paesi. Con il moltiplicarsi degli studi sull’effettiva dimensione di questo fenomeno, si è registrata negli ultimi anni un’attenzione via via crescente da parte della comunità scientifica, delle istituzioni e della società civile ma ciò nonostante lo spreco alimentare fa registrare, ancora oggi, dati allarmanti e, una preoccupazione ancora maggiore, è la paradossale coesistenza di alti volumi di FLW e povertà alimentare.
Questo lavoro si è soffermato sulla riduzione della perdita dei prodotti ortofrutticoli nella fase di post raccolta, in modo particolare sullo spreco che si verifica come conseguenza della modalità di confezionamento di prodotti, attraverso l’introduzione di una innovazione che, sulla base dei test di laboratorio, consente di ottenere ragguardevoli risultati in termini di miglioramento della shelf life: il BlowDevice® (BD), valvola sviluppata da Di Renzo et. al. e coperta da brevetto nazionale ed internazionale, che, consentendo il flusso bidirezionale dei gas, fornisce proprietà traspiranti agli imballaggi per prodotti ortofrutticoli freschi.
Obiettivo della presente tesi è verificare la sostenibilità, dal punto di vista economico, dell’investimento connesso all’adozione del dispositivo BlowDevice® da parte dell’Organizzazione di Produttori “Armonia” con sede a Battipaglia (SA), che è una delle maggiori del Mezzogiorno d’Italia, nata nel 2009 dall’unione di alcune tra le più grandi Organizzazioni di Produttori del Sud Italia.
La stima del potenziale di mercato di questa nuova tecnologia, applicata alle confezioni di alcuni prodotti ortofrutticoli individuato come target (ciliegie, fragole, kiwi, uva tavola, rucola), è stata condotta mediante un confronto tra lo scenario di base, dato dall’assenza dell’investimento, e lo scenario alternativo caratterizzato dall’introduzione di questo nuovo metodo di confezionamento.
L’adozione del BlowDevice® incide sui costi operativi dell’azienda, determinando un aumento sia dei costi fissi che dei costi variabili, tuttavia determina una riduzione della quantità di prodotto non commercializzata perché deteriorata durante il trasporto verso la grande distribuzione, incrementando i ricavi di vendita.
I risultati ottenuti hanno evidenziato da un lato che l’introduzione del BD® richiede un incremento del prezzo di vendita dei prodotti almeno pari al 4,98%, tuttavia, dai dati raccolti, si può vedere che, se l’azienda riuscisse a consegnare tutti i prodotti in ingresso, azzerando quindi gli sprechi, il prezzo di pareggio sarebbe inferiore a quello dello scenario di base, e, sulla base di test di laboratorio relativi al BD®, tale risultato è conseguibile se la frutta confezionata è in buono stato di conservazione a dimostrazione di come è importante che l’intera catena di approvvigionamento sia efficiente.Food waste is one of the most debated topics of the last decade and represents a priority on the political agenda of all countries. With the increasing number of studies on the actual scale of this phenomenon, in recent years, there has been growing attention from the scientific community, institutions, and civil society. However, food waste still shows alarming figures today, and an even greater concern is the paradoxical coexistence of high FLW volumes and food poverty.
This work focused on reducing the loss of fruit and vegetable products in the post-harvest phase, particularly on waste resulting from packaging methods, by introducing an innovation that, based on laboratory tests, achieves remarkable results in terms of shelf-life improvement: the BlowDevice® (BD). This valve, developed by Di Renzo et al. and covered by national and international patents, enables the bidirectional flow of gases, providing breathable properties to packaging for fresh fruit and vegetable products.
The objective of this thesis is to assess the economic sustainability of the investment related to the adoption of the BlowDevice® by the Producer Organization “Armonia”, based in Battipaglia (SA). “Armonia” is one of the largest producer organizations in Southern Italy, founded in 2009 through the union of some of the most significant producer organizations in the region.
The market potential estimation of this new technology, applied to the packaging of selected target fruit and vegetable products (cherries, strawberries, kiwis, table grapes, arugula), was conducted by comparing the baseline scenario—where no investment is made—with an alternative scenario featuring the introduction of this new packaging method.
The adoption of BlowDevice® impacts the company’s operating costs, leading to an increase in both fixed and variable costs. However, it also reduces the amount of unsellable products that deteriorate during transportation to large-scale retail distribution, thus increasing sales revenues.
The results show that implementing BD® requires an increase in the selling price of products by at least 4.98%. However, the collected data indicate that if the company were able to deliver all incoming products, thereby eliminating waste, the breakeven price would be lower than that of the baseline scenario. Based on laboratory tests related to BD®, this outcome is achievable if the packaged fruit is well-preserved, demonstrating the importance of an efficient supply chain
XLA Petiole Index: A Novel Hydraulic Function Metric for Interpreting Drought-Induced Dieback in Mediterranean Ring-Porous Oak Forests
Get PDFClimate-induced forest mortality is an increasing global phenomenon occurring at both regional and local scales, with implications for ecosystem functioning and the provision of essential ecosystem services. In recent years, the Italian peninsula has experienced widespread oak forest decline, with forests showing increased susceptibility to severe heat waves and prolonged droughts. Our study examined a drought-induced tree mortality episode in the Mediterranea region (Pollino National Park, Southern Italy) focusing on deciduous oak forest stands (Quercus frainetto Ten.). We employed a comprehensive approach, combining ecophysiological and dendro-ecological analyses to compare non-decaying (ND) and decaying (D) coexisting trees. Recent advancements in understanding the relationship between petiole xylem anatomy and leaf form and function have revealed a positive correlation between petiole vessel diameter and leaf size, both within and across species. Leaf petioles, serving as the singular entry point for water into the leaf venation system, offer a standardized basis for comparing xylem investment with downstream transpirational demands. To quantify this relationship, we employed a novel index derived from quantitative wood anatomy of petioles. This integrative trait characterizes leaf water transport function by measuring the ratio of cross-sectional xylem area (XA) at the petiole to the downstream leaf area, termed the XLA petiole Index. Our assessment of XLA petiole variation can provide evidence supporting a safety-efficiency trade-off in oak leaves, a crucial aspect of plant hydraulic strategy
Diritto Amministrativo ed Economia Circolare. Strumenti di contrasto alle Ecomafie in ottica de iure condendo.
No full textEcomafias represent a problem of national and supranational importance, with serious impacts on the environment, on the economy and on the public health. Circular economy is the antithesis of the criminal purposes of eco-mafias and represents a means to fight the spread of the eco-mafia phenomenon. The range of action of eco-mafias is wide and goes beyond the national borders. Administrative law, with its distinctly preventive vocation, together with a change of mentality and with an efficient governmental and institutional action, represents a further expedient against the spread of eco-mafias. The thesis aims to offer concrete solutions and remedies that can limit the proliferation of environmental corruption. The main food for thought and the stimuli seen from a de iure condendo perspective are the result of the analysis of the regulatory instruments in force and the concrete attitude of environmental offences in the case studies analyzed. The impact of the proposed solutions contributes to fueling the public and legal debate on the issue
Collapse fragility curves of RC piers with corroded rebars
No full textAgeing and degradation of Reinforced Concrete (RC) bridges can significantly increase their seismic vulnerability and have a significant impact on expected economic losses. In this study, the seismic performance of typical single-shaft piers with corroded rebars is examined through extensive Multi-Stripe non-linear response time-history Analyses (MSA). Piers with different cross sections and heights, featuring different deterioration scenarios, characterized by different corrosion patterns and severity levels of corrosion, are investigated. MSA are performed using twenty pairs of ground motion records consistent with the seismic hazard of the cities of L’Aquila (central Italy) and Naples (southern Italy), for nine different earthquake intensity levels with return periods ranging from 50 to 100.000 years. Lognormal fragility curves associated with pier collapse are derived to account for record-to-record variability. Finally, the annual failure rates associated with collapse are derived to evaluate the structural reliability of each model both in the as-built and deteriorated conditions
Uniform and Convergence of the Hermite Interpolation at Pollaczek–Laguerre Zeros
Get PDFThe paper deals with the weighted polynomial approximation of functions defined on (0,+∞), which can grow exponentially both at +∞ and at 0. To this aim, we introduce interpolating operators of Hermite and Hermite–Fejér-type, based at the zeros of Pollaczek–Laguerre type orthogonal polynomials. We prove that these processes converge in weighted uniform and Lp-norms and provide sharp error estimates showing that the order of convergence is the same as the best polynomial approximation, under suitable assumptions