138 research outputs found
Renewable Energy Communities in Positive Energy Districts: A Governance and Realisation Framework in Compliance with the Italian Regulation
Renewable energy communities, first outlined in the European Directives and recently transposed into the Italian regulatory framework, are introduced as innovative entities capable of fostering cooperation between active and passive users involved in the production, sharing, and use of locally produced energy according to innovative management schemes. Renewable energy communities empower the end-customers. Citizens and legal entities are committed to a rational and economical use of energy to achieve the community’s climate neutrality goals and pursue the ecological and energy transition objectives defined in the national recovery and resilience plan. In the future, a significant number of energy communities different actors participating from the residential, industrial, commercial, and tertiary sectors are expected to develop within city districts or in suburban settings. This paper proposes and develops a methodology capable of bridging the complexity that can characterise the prototyping, implementation, and management of an energy community within a positive energy district. The approach presented here can also be extended to other application contexts in urban or rural settings. Requirements and best practices for administrative, technical, and technological management have been identified to achieve this goal. Italy is one of the first states to embed in its regulatory framework the European Directives regarding renewable energy communities. These will have a significant impact on network management models and will provide new ways for creating social inclusion that may help achieve climate sustainability goals. A governance model has been formalised for the empowerment of energy community members, outlining a framework useful for planning the proper implementation of a renewable energy community according to current Italian regulations
Contactless Energy Transfer Techniques for Industrial Applications. Power and Data Transfer to Moving Parts
Contactless energy transfer (CET) systems are gaining increasing interest in the automatic machinery industries. For this reason, circuit equivalent networks of CET systems considered in the literature are introduced with emphasis on their industrial applicability. The main operating principles and the required compensating networks, along with different topologies of power supplies optimised for wireless powering, are discussed. The analysis of the wireless transfer, at the maximum efficiency, of high power levels shows that, in the kHz range, highly coupled inductive links are needed and soft-switching power sources required. The employment of CET units in controlled systems requires combining a link for data communication with the wireless power channel. At low frequencies, capacitive and inductive couplings are integrated in a unique platform to implement the wireless data and power links, respectively. Differently, at UHF, an increased data channel transfer efficiency is made possible by exploiting auto-resonant structures, such as split-ring resonators instead of capacitances, one at each far-end side of the link. The design procedure of a power CET system, including the dc/ac converter, a rotary transformer and its windings, is discussed and the results presented. A different version of a WPT system, which involves multiple transmitting coils and a sliding receiver, is also presented. A low frequency RFID capacitive data link is then combined with the rotary CET unit to provide the temperature feedback of a controlled system, wherein the rectifying part of a passive tag is exploited to simultaneously power and read a temperature probe. Subsequently, a split-ring based near-field UHF data link is designed to ensure an improved temperature detection in terms of accuracy and resolution. The sensor readout is performed at the transmitter side by measuring the reflected power by the load rectifier
Achieving Net Zero Condominiums through Energy Community Sharing
The European energy transition process is geared toward improving the economic viability of the energy sector through its democratization, which includes enabling citizens to generate, share, and sell energy produced by renewable sources. The current directives have led to the creation of energy communities and collective self-consumption groups to engage and raise awareness among citizens, with the goal of achieving social, economic, and environmental benefits through shared renewable energy generation and consumption. In the near future, more and more of these initiatives are anticipated; therefore, innovative technological tools are necessary to assist their growth path. This research introduces a multi-criteria techno-economic simulation framework that enables the evaluation of several investment scenarios for various plant sizes and energy prices. The findings are useful during the investment planning phase as they help guide decision-making toward the objectives of economic, energy, and environmental sustainability. To evaluate the methodology, a case study of a collective self-consumption group located in a smart building in Italy is proposed. The results are discussed from statistical, technical, economic, and financial standpoints, demonstrating how the proposed approach can contribute to the development of collective self-consumption groups, risk hedging, and the goal of developing energy self-sufficiency based on the net-zero energy building concept
Simple Dynamics for Plurality Consensus
We study a \emph{Plurality-Consensus} process in which each of anonymous
agents of a communication network initially supports an opinion (a color chosen
from a finite set ). Then, in every (synchronous) round, each agent can
revise his color according to the opinions currently held by a random sample of
his neighbors. It is assumed that the initial color configuration exhibits a
sufficiently large \emph{bias} towards a fixed plurality color, that is,
the number of nodes supporting the plurality color exceeds the number of nodes
supporting any other color by additional nodes. The goal is having the
process to converge to the \emph{stable} configuration in which all nodes
support the initial plurality. We consider a basic model in which the network
is a clique and the update rule (called here the \emph{3-majority dynamics}) of
the process is the following: each agent looks at the colors of three random
neighbors and then applies the majority rule (breaking ties uniformly).
We prove that the process converges in time with high probability, provided that .
We then prove that our upper bound above is tight as long as . This fact implies an exponential time-gap between the
plurality-consensus process and the \emph{median} process studied by Doerr et
al. in [ACM SPAA'11].
A natural question is whether looking at more (than three) random neighbors
can significantly speed up the process. We provide a negative answer to this
question: In particular, we show that samples of polylogarithmic size can speed
up the process by a polylogarithmic factor only.Comment: Preprint of journal versio
The curved Mimetic Finite Difference method: allowing grids with curved faces
We present a new mimetic finite difference method for diffusion problems that
converges on grids with \textit{curved} (i.e., non-planar) faces. Crucially, it
gives a symmetric discrete problem that uses only one discrete unknown per
curved face. The principle at the core of our construction is to abandon the
standard definition of local consistency of mimetic finite difference methods.
Instead, we exploit the novel and global concept of -consistency.
Numerical examples confirm the consistency and the optimal convergence rate of
the proposed mimetic method for cubic grids with randomly perturbed nodes as
well as grids with curved boundaries.Comment: Accepted manuscrip
Sharp Thresholds for a SIR Model on One-Dimensional Small-World Networks
We study epidemic spreading according to a
\emph{Susceptible-Infectious-Recovered} (for short, \emph{SIR}) network model
known as the {\em Reed-Frost} model, and we establish sharp thresholds for two
generative models of {\em one-dimensional small-world graphs}, in which graphs
are obtained by adding random edges to a cycle.
In -regular graphs obtained as the union of a cycle and a random perfect
matching, we show that there is a sharp threshold at for the contagion
probability along edges.
In graphs obtained as the union of a cycle and of a
Erd\H{o}s-R\'enyi random graph with edge probability , we show that there
is a sharp threshold for the contagion probability: the value of
turns out to be for the sparse case yielding an
expected node degree similar to the random -regular graphs above.
In both models, below the threshold we prove that the infection only affects
nodes, and that above the threshold it affects
nodes.
These are the first fully rigorous results establishing a phase transition
for SIR models (and equivalent percolation problems) in small-world graphs.
Although one-dimensional small-world graphs are an idealized and unrealistic
network model, a number of realistic qualitative phenomena emerge from our
analysis, including the spread of the disease through a sequence of local
outbreaks, the danger posed by random connections, and the effect of
super-spreader events.Comment: 28 pages, 0 figure
Bevacizumab and temozolomide in secondary gliomatosis from gemistocytic astrocytoma: a case report
Gliomatosis cerebri is a rare diffuse glioma with a growth pattern consisting of exceptionally extensive infiltration of the CNS with involvement of at least three lobes. It may appear de novo (primary gliomatosis) or result from the spreading of a focal glioma (secondary gliomatosis). Bevacizumab is a monoclonal antibody anti-VEGF active against recurrent high grade gliomas after standard therapy. We report the case of a 41-year-old man with a secondary gliomatosis treated with bevacizumab and temozolomide who responded and the response lasted 17 months. Moreover, we focus on the side effects (hypertension, deep vein thrombosis) induced by bevacizumab and their effective treatments
Temozolomide as salvage treatment for recurrent intracranial ependymomas of the adult: a retrospective study
BACKGROUND: Few data are available on temozolomide (TMZ) in ependymomas. We investigated the response, survival, and correlation with MGMT promoter methylation in a cohort of patients with adult intracranial ependymoma receiving TMZ as salvage therapy after failure of surgery and radiotherapy. PATIENTS AND METHODS: We retrieved clinical information from the institutional database and follow-up visits, and response to TMZ on MRI was evaluated according to the MacDonald criteria. RESULTS: Eighteen patients (median age, 42 y), with either WHO grade III (10) or grade II (8) ependymoma were evaluable. Tumor location at diagnosis was supratentorial in 11 patients and infratentorial in 7. Progression before TMZ was local in 11 patients, local and spinal in 6 patients, and spinal only in one patient. A median of 8 cycles of TMZ (1–24) was administered. Response to TMZ consisted of complete response (CR) in one (5%) patient, partial response (PR) in 3 (17%) patients, stable disease (SD) in 7 (39%) patients, and progressive disease (PD) in 7 (39%) patients. Maximum response occurred after 3, 10, 14, and 15 cycles, respectively, with neurological improvement in 2 patients. All 4 responding patients were chemotherapy naïve. Both anaplastic (2) and grade II (2) tumors responded. Median progression-free survival and overall survival were 9.69 months (95% CI, 3.22–30.98) and 30.55 months (95% CI, 12.85–52.17), respectively. MGMT methylation was available in 11 patients and was not correlated with response or outcome. CONCLUSION: TMZ has a role in recurrent chemo-naïve adult patients with intracranial ependymoma, regardless of tumor grade and MGMT methylation. We suggest that, after failure of surgery and radiotherapy, TMZ should be considered as a possible first-line treatment for recurrent ependymoma
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