41 research outputs found
Temporal extension of the wind speed in order to estimate the annual production of a wind turbine
No full textThe wind sector is facing the challenge of mini and micro generation, but the unpredictability of wind makes difficult to estimate the real potentiality of a possible wind site and consequently the correct sizing of the turbine. Usually, at least five years of on-site measurement of wind speed are considered adequate to permit a good estimation of a site potentiality, but many Authors suggest longer times. These waiting times are impractical for mini wind plants where small size investors are involved. For this reason, in the last years some techniques have been developed aimed at the extension of the data in order to give reliable estimation starting from short time measurements. In this paper, a MCP (Measure Correlate Predict) technique has been implemented able to integrate the available onsite measurements with those coming from one or more weather stations located near the site under analysis in order to forecast a typical annual speed trend. Then, this model has been integrated into a model based on Monte Carlo method able to evaluate the effect of wind variability. A probability distribution of the Annual Energy Production of a site can so be evaluated. An example of application of the method to different places is presented in the paper. Some considerations about the minimum measurement time to an acceptable estimation of annual production, and about the dependency of the reliability of the method on the site characteristics are reported, too
Structural Batteries in Aviation: A Preliminary Sizing Methodology
No full textA significant research effort in aviation is currently focused on the integration of electric or hybrid-electric power-trains onboard aircraft in an effort to improve efficiency and environmental friendliness. New designs incorporating these novel propulsion systems face the issue of penalizing battery characteristics, especially in terms of limited energy and power density performance, in turn imposing a toll on the inert weight of the machine. A possible solution to this issue is that of structural batteries. These are similar in structure to carbon fiber composites, where the matrix features dielectric characteristics, making the structure capable of storing electric energy while retaining the capability to withstand mechanical loads. The adoption of this technology, currently under advanced development, shall enable significant weight savings; yet it also raises relevant issues concerning aircraft sizing procedures that need to be conceived taking into account the specific characteristics of such multifunctional materials. This paper faces the new problem of aircraft initial design in presence of structural batteries. First, it presents a method for aircraft preliminary weight sizing, where the double effect of structural batteries on both structural mass and energy storage mass is considered. Subsequently, a procedure to size an airframe structure with the adoption of structural batteries in key components is shown, based on a weight-optimal approach. The complete sizing procedure is illustrated through an award-winning test case in the General Aviation category
Genetically Optimized Extended Kalman Filter for State of Health Estimation Based on Li-Ion Batteries Parameters
No full textThe state of health (SOH) is among the most important parameters to be monitored in lithium-ion batteries (LIB) because it is used to know the residual functionality in any condition of aging. The paper focuses on the application of the extended Kalman filter (EKF) for the identification of the parameters of a cell model, which are required for the correct estimation of the SOH of the cell. This article proposes a methodology for tuning the covariance matrices of the EKF by using an optimization process based on genetic algorithms (GA). GAs are able to solve the minimization problems for the non-linear functions, and they are better than other optimization algorithms such as gradient descent to avoid the local minimum. To validate the proposed method, the cell parameters obtained from the EKF are compared with a reference model, in which the parameters have been determined with proven procedures. This comparison is carried out with different cells and in the whole range of the cell’s SOH, with the aim of demonstrating that a single tuning procedure, based on the proposed GA process, is able to guarantee good accuracy in the estimation of the cell parameters at all stages of the cell’s life
Descrizione dei principali indicatori di qualità
No full textIl capitolo riporta la valutazione delle caratteristiche psicometriche di uno strumento costruito ad hoc per valutare la soddisfazione del paziente ospedaliero. Vengono inoltre descritti gli esiti di un'indagine portata a compimento presso l'Azienda sanitaria di Desenzano del Garda. Tali risultati riguardano un campione di quasi 1200 interviste individuali compiute al momento della dimissione
Prognostic significance of estrogen and progesterone receptors (RE and PR) in 234 breast cancer patients.
No full textReactive oxygen intermediates modulate nitric oxide signaling in the plant hypersensitive disease-resistance response
No full textThe mechanisms involved in plant defense show several similar characteristics with the innate immune systems of vertebrates and invertebrates. In animals, nitric oxide (NO) cooperates with reactive oxygen intermediates (ROI) to kill tumor cells and is also required for macrophage killing of bacteria. Such cytotoxic events occur because unregulated levels of NO determine its diffusion-limited reaction with O2– generating peroxynitrite (ONOO–), a mediator of cellular injury in many biological systems. In soybean suspension cells, unregulated NO production during the onset of a pathogen-induced hypersensitive response (HR) is not sufficient to activate the hypersensitive cell death, which is triggered only by fine tuning the NO/ROI ratio. Furthermore, that hypersensitive cell death is activated following interaction of NO with H2O2, rather than O2–. Increasing O2– levels reduces NO-derived toxicity, and the addition of ONOO– to soybean suspensions does not affect cell viability. Consistently with the fact that ONOO– is not an essential mediator of NO/RO-induced cell death, during the HR superoxide dismutase (SOD) accelerates O2– dismutation to H2O2 and therefore minimizes the loss of NO by reaction with O2– and triggers hypersensitive cell death through the NO/H2O2 synergism. Consequently, the rates of production and dismutation of O2– generated during the oxidative burst play a crucial role in modulating NO signaling through the cell death pathway, which proceeds through mechanisms different from those commonly observed in animals
Reactive oxygen intermediates modulate nitric oxide signaling in the plant hypersensitive disease resistance response
No full textAnalysis of membrane proteins from fractioned red cell by 2-D electrophoresis: comparison between normal and sickle red cells.
No full textSpecial Session: D-MATE: A Design Methodology for Connecting Automatic Test Equipment in Industry 4.0
No full textWith the growing presence of semiconductor devices in healthcare, automotive, and consumer electronics, Automatic Test Equipment (ATE) systems play an increasingly vital role in ensuring quality and reliability during validation. Despite their importance, ATE systems often operate in isolation from other manufacturing processes, limiting interoperability and integration potential. Consequently, fully incorporating ATE systems within the Industry 4.0 framework remains a largely unaddressed challenge. To bridge this gap, we propose adopting Open Platform Communications Unified Architecture (OPC UA), the industry de-facto standard communication protocol for machines, with an accompanying specification tailored to ATE systems. We
developed and validated our information model on an advanced ATE system, demonstrating its practical application. The results showcase the successful integration of the ATE system into a fully-fledged Industrial Computer Engineering (ICE) laboratory demonstrator. This study validates the effectiveness of our model in a real-world scenario and highlights the significance of our integration approach within the context of Industry 4.0
