Evaluating Distributed Time-Varying Generation Through a Multiobjective Index

In the last decade, distributed generation, with its various technologies, has increased its presence in the energy mix presenting distribution networks with challenges in terms of evaluating the technical impacts that require a wide range of network operational effects to be qualified and quantified. The inherent time-varying behavior of demand and distributed generation (particularly when renewable sources are used), need to be taken into account since considering critical scenarios of loading and generation may mask the impacts. One means of dealing with such complexity is through the use of indices that indicate the benefit or otherwise of connections at a given location and for a given horizon. This paper presents a multiobjective performance index for distribution networks with time-varying distributed generation which consider a number of technical issues. The approach has been applied to a medium voltage distribution network considering hourly demand and wind speeds. Results show that this proposal has a better response to the natural behavior of loads and generation than solely considering a single operation scenario

Evaluating distributed generation impacts with a multiobjective index

Evaluating the technical impacts associated with connecting distributed generation to distribution networks is a complex activity requiring a wide range of network operational and security effects to be qualified and quantified. One means of dealing with such complexity is through the use of indices that indicate the benefit or otherwise of connections at a given location and which could be used to shape the nature of the contract between the utility and distributed generator. This paper presents a multiobjective performance index for distribution networks with distributed generation which considers a wide range of technical issues. Distributed generation is extensively located and sized within the IEEE-34 test feeder, wherein the multiobjective performance index is computed for each configuration. The results are presented and discussed

La raccolta dati per la diagnosi infermieristica

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La Diagnosi Infermieristica: II. La Formulazione della Diagnosi Infermieristica

La diagnosi infermieristica, seconda fase del processo infermieristico, è un giudizio clinico riguardante le risposte della persona, della famiglia o della comunità a problemi di salute/processi vitali attuali o potenziali. Essa costituisce la base sulla quale scegliere gli interventi infermieristici volti a raggiungere dei risultati di cui l'infermiere è responsabile. La diagnosi infermieristica esprime il giudizio professionale sulle condizioni del paziente, sulle sue risposte ai trattamenti ricevuti e sulle necessità di assistenza infermieristica. La NANDA propone tre modelli di diagnosi: reali, di rischio, di benessere. La struttura della diagnosi infermieristica si compone di tre elementi utili essenzialmente per l'adozione di un linguaggio infermieristico condiviso. Per questo motivo è usata una terminologia specifica per diagnosticare in modo infermieristico. Gli elementi componenti sono tre: titolo, caratteristiche definenti, fattori correlati. Il titolo deve "qualifcare" la tipologia del problema; le caratteristiche definenti sono l'equivalente dei segni e dei sintomi soggettivi ed oggettivi presenti in relazione ad una determinata diagnosi; i fattori correlati sono in pratica le cause, i fattori eziologici che determinano una certa situazione; si possono raggruppare in quattro categorie: fisiopatologici, situazionali, fasi maturative, trattamenti. Il caso clinico suggerito prevede l'individuazione delle diagnosi infermieristiche evidenziate dai dati raccolti, sempre secondo la metodologia di Carpenito

Existence of positive solutions of a superlinear boundary value problem with indefinite weight

We deal with the existence of positive solutions for a two-point boundary value problem associated with the nonlinear second order equation $u''+a(x)g(u)=0$. The weight $a(x)$ is allowed to change its sign. We assume that the function $g\colon\mathopen{[}0,+\infty\mathclose{[}\to\mathbb{R}$ is continuous, $g(0)=0$ and satisfies suitable growth conditions, so as the case $g(s)=s^{p}$, with $p>1$, is covered. In particular we suppose that $g(s)/s$ is large near infinity, but we do not require that $g(s)$ is non-negative in a neighborhood of zero. Using a topological approach based on the Leray-Schauder degree we obtain a result of existence of at least a positive solution that improves previous existence theorems.Comment: 12 pages, 4 PNG figure

Time-series based maximization of distributed wind power generation integration

Energy policies and technological progress in the development of wind turbines have made wind power the fastest growing renewable power source worldwide. The inherent variability of this resource requires special attention when analyzing the impacts of high penetration on the distribution network. A time-series steady-state analysis is proposed that assesses technical issues such as energy export, losses, and short-circuit levels. A multiobjective programming approach based on the nondominated sorting genetic algorithm (NSGA) is applied in order to find configurations that maximize the integration of distributed wind power generation (DWPG) while satisfying voltage and thermal limits. The approach has been applied to a medium voltage distribution network considering hourly demand and wind profiles for part of the U.K. The Pareto optimal solutions obtained highlight the drawbacks of using a single demand and generation scenario, and indicate the importance of appropriate substation voltage settings for maximizing the connection of MPG