196,131 research outputs found
Incentive mechanisms for the secure integration of renewable energy in local communities: A game-theoretic approach
No full textIn the context of local energy communities (LECs), prosumers are the main actors, as they can both produce and consume energy. Prosumers can interact with each other, and peer-to-peer (P2P) energy trading allows prosumers belonging to the same LEC to exchange energy with each other. This allows energy production to be consumed internally by the community, which has the benefits of reducing costs for energy consumption and reducing the amount of energy traveling from/to the external grid, which causes transmission losses and wears and tear to the grid itself. This paper proposes a design for the P2P market from a game-theoretical point of view, where prosumers are modeled as selfish agents whose goal is to maximize their own profits in energy trading. The purposes of this market design are to (i) discourage prosumers from curtailing their own energy production, (ii) avoid congestions as much as possible, (iii) encourage self-consumption from prosumers, and (iv) guarantee that the selfish behavior of prosumers allows for a common strategy. Furthermore, this work considers the possibility of prosumers making coalitions between themselves, and show how this still allows for the existence of a common strategy. Simulations of the proposed market design have been run on data from a grid in Cardiff, UK, and show how the proposed mechanism allows for cost reduction and encourages energy self-consumption. Experiments results show that the system discourages the formation of small coalitions, and encourages instead cooperation from all the prosumers in the community
Unusual accumulation of S-methylmethionine in aerobic-etiolated and in anoxic rice seedlings : an 1H-NMR study
No full textAn unknown signal at 2.93 ppm in 1H-NMR spectra of rice, Oryza sativa, was assigned to the methyl groups of sulphur-methylmethionine (SMM), thereby devising a new method for the determination of this compound. Rice seedlings growing aerobically in the dark and in the light engaged for the synthesis of SMM an amount of Met corresponding to 23 and 8%, respectively, of the total seed reserves of this amino acid. In etiolated shoots, SMM reached 1.2 micromol g(-1) fresh weight, an unusually high level in vegetative tissues of wild-type plants. This is compared to a value of 0.4 micromol g(-1) fresh weight in green tissues. A decreased demand for Met during growth caused the higher accumulation of SMM in etiolated, rather than green, tissues. At the same time, dark seedlings were endowed with a readily utilizable and translocable alternative form of Met, as shown by retrieval of SMM from the coleoptile. The importance of methyl group storage in SMM is shown by comparison with choline and choline phosphate pools
The determinants of functional capacity in left ventricular assist device patients: many actors with not well defined roles
No full textImprovement in hemodynamic parameters is routinely demonstrated in patients implanted with continuous-flow left ventricular assist devices (CF-LVADs). However, functional capacity assessed by cardiopulmonary exercise test (CPET), following LVAD implantation, remains considerably restricted. In this review, we analyzed the current knowledge on the causes of the persistent limitation in exercise capacity in CF-LVAD patients. Limitation to exercise is multifactorial and involves: LVAD factors (fixed CF-LVAD pump speed), native cardiac factors (residual function of native left ventricle, right ventricular dysfunction, aortic valve abnormalities), comorbidities (abnormal skeletal muscle metabolism, low skeletal muscle mass, anemia), patient's characteristics (age, physical deconditioning). In addition, we emphasize the role of some potential therapeutic strategies like the increase in CF-LVAD pump speed according to the patient's activity, the echo-optimization of the device (paying attention to right ventricular function and aortic valve opening), the implementation of physical rehabilitation and the treatment of potentially reversible extracardiac factors (anemia, muscle deconditioning, obesity)
A Game-Theoretical Incentive Mechanism for Local Energy Communities
No full textLocal energy communities (LECs) are structures based on the collaboration of neighbouring prosumers for suiting their energy requests. Prosumers are users participating in the community, which are able to produce energy rather than just consuming it. These communities have the purpose to incentivize usage of renewable energy. Inside them, it is possible to have members that trade energy in a peer-to-peer (P2P) fashion: prosumer can trade their energy surplus with consumers, so that profits remain inside the community and energy is not unnecessarily taken from outside, which avoids strain on the grid and transmission losses. In this work, the goal is to create a game theory model of a P2P market for LECs which takes into account the behavior of prosumers, assuming each of them will aim for their own benefit. The model has the objective to incentivize prosumers to self-consume their own energy, and balance as much as possible production and consumption through the community. The proposed model is described and analyzed with respect to other existing models with similar purposes, both from a theoretical and an empirical point of view. Results show that our model obtains good performances in all the analyzed aspects, outperforming existing ones
Intelligent Local Energy Communities: A Multiagent System Approach
No full textThe electric power grid undergoes a transformation, with many consumers becoming both producers and consumers of electricity. This transformation poses challenges to the existing grid as it was not designed to have reverse power flows. Local energy communities are effective in addressing those issues and engaging grid users to play an active role in the energy transition. Such communities encourage the consumption of the excess of renewable energy locally, which reduces the stress on the grid and the costs for the users. In this paper, we present a multiagent system developed to implement an intelligent local energy community. The multiagent system models the energy grid as a network of computational agents that solve energy flow problems in a coordinated way and use the solutions for controlling flexible loads. The model effectively distributes the tasks among the agents considering the flows of electricity and heat. The Alternative Direction Method of Multipliers determines the agent interaction protocol. The obtained results demonstrate the ability of the multiagent system to automate an intelligent operation of the community while reducing the energy costs and ensuring the grid stability
Synthesis and in vitro antitumoral activity of new hydrazinopyrimidine-5-carbonitrile derivatives
No full textA new series of 2-amino-6-(2-alkyl or arylidenehydrazinyl)-4-(dialkylamino)pyrimidine-5-carbonitriles,5–24, were syn-thesized in satisfactory overall yield, using 2-amino-4-(dialkylamino)-6-hydrazino-5-pyrimidinecarbonitriles 3, 4, as key intermedi-ates, by applying classical synthetic methods to construct the hydrazone moiety at C-6 of the pyrimidine ring. Hydrazinopyrimidine
derivatives 5–24were evaluated for their in vitro anticancer activity toward cell lines of nine different types of human cancers. Some
of the newly prepared compounds demonstrated inhibitory effects on the growth of a wide range of cancer cell lines generally at
10
5
M level and in some cases at 10
7
M concentrations
Synthesis and in vitro antitumoral activity of new 3,5-dicyanopyridine derivatives
No full textA new series of 2-amino-4-aryl-6-dialkylamino-3,5-dicyanopyridines, 20–47, were synthesized in satisfactory overall yield,
through a simple synthetic strategy using 3-amino-3-(dialkylamino)-propenenitriles 1 and 2 as key intermediates. 3,5-Dicyanopyridine
derivatives 20–47 were evaluated for their in vitro anticancer activity toward cell lines of nine different types of human cancers.
Some of the newly prepared compounds demonstrated inhibitory effects on the growth of a wide range of cancer cell lines generally
at 106 M level and in some cases at 108 M concentration
Studio del deficit di alfa-1 antitripsina nella popolazione Sarda
No full textIntroduzione:
L’ AATD e’ una forma genetica abbastanza comune di malattia epatica nel bambino e di enfisema polmonare ed epatopatia nell’adulto, pur facendo parte delle malattie rare. Si manifesta spesso con sintomatologia clinica aspecifica, con tempi e modalità variabili, e spesso non sono utilizzati i test molecolari per una diagnosi definitiva. La diagnosi di laboratorio è spesso casuale e può essere posta partendo dall’assenza del picco delle α1-globuline all’ESP. Tale carenza induce a sospettare l’AATD, che deve essere prima confermata con il dosaggio sierico e quando necessario deve essere studiato il profilo genico. Per questi motivi, è ragionevole pensare che l’AATD sia una condizione clinica sottostimata, da considerarsi probabilmente non una malattia rara, ma raramente diagnosticata. In Sardegna i casi di AATD sono correlati ad una mutazione nota come M-Malton/ M-Cagliari, rarissima nelle altre popolazioni, o alla mutazione S. Non disponiamo ancora di dati attendibili circa la frequenza di questa mutazione. Scopo del lavoro è quello di individuare i soggetti con AATD e calcolare la frequenza della mutazione nella popolazione da noi considerata, trovare un cut-off decisionale di laboratorio da utilizzare per stabilire quali pazienti studiare per la mutazione
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