512 research outputs found

    New dispatching paradigm in power systems including EV charging stations and dispersed generation: A real test case

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    Electric Vehicles (EVs) are becoming one of the main answers to the decarbonization of the transport sector and Renewable Energy Sources (RES) to the decarbonization of the electricity production sector. Nevertheless, their impact on the electric grids cannot be neglected. New paradigms for the management of the grids where they are connected, which are typically distribution grids in Medium Voltage (MV) and Low Voltage (LV), are necessary. A reform of dispatching rules, including the management of distribution grids and the resources there connected, is in progress in Europe. In this paper, a new paradigm linked to the design of reform is proposed and then tested, in reference to a real distribution grid, operated by the main Italian Distribution System Operator (DSO), e-distribuzione. First, in reference to suitable future scenarios of spread of RES-based power plants and EVs charging stations (EVCS), using Power Flow (PF) models, a check of the operation of the distribution grid, in reference to the usual rules of management, is made. Second, a new dispatching model, involving DSO and the resources connected to its grids, is tested, using an Optimal Power Flow (OPF) algorithm. Results show that the new paradigm of dispatching can effectively be useful for preventing some operation problems of the distribution grids

    Leaders\u2019 competence and warmth: Their relationships with employees\u2019 well-being and organizational effectiveness

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    The aim of this work was to investigate competence and warmth \u2014 the two basic dimensions of social judgment \u2014 as dimensions employees use to evaluate their supervisors. A mediation model was tested in which supervisor\u2019s perceived competence and warmth were associated with relevant outcomes (lower burnout, weaker turnover intentions, more frequent citizenship behaviors) through the mediation of affective organizational commitment (AOC). In Study 1, data were collected from employees of a company in the water service sector. In Study 2, participants were financial promoters. In Study 3, the sample included employees from different organizations. As hypothesized, the perception of one\u2019s supervisor as competent (Studies 1-3) and warm (Study 3) was related to employees\u2019 lower burnout, weaker turnover intentions, more frequent prosocial behaviors through the mediation of AOC. Theoretical and practical implications of findings are discussed

    EV charging stations and RES-based DG: A centralized approach for smart integration in active distribution grids

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    Renewable Energy Sources based (RES-based) Dispersed Generation (DG) and Electrical Vehicles (EVs) charging systems diffusion is in progress in many Countries around the word. They have huge effects on the distribution grids planning and operation, particularly on MV and LV distribution grids. Many studies on their impact on the power systems are ongoing, proposing different approaches of managing. The present work deals with a real application case of integration of EVs charging stations with ES-based DG. The final task of the integration is to be able to assure the maximum utilization of the distribution grid to which both are connected, without any upgrading action, and in accordance with Distribution System Operators (DSOs) needs. The application of the proposed approach is related to an existent distribution system, owned by edistribuzione, the leading DSO in Italy. Diverse types of EVs supplying stations, with diverse diffusion scenarios, have been assumed for the case study; various Optimal Power Flow (OPF) models, based on diverse objective functions, reflecting DSO necessities, have been applied and tried. The obtained results demonstrate that a centralized management approach by the DSO, could assure the respect of operation limits of the system in the actual asset, delaying or avoiding upgrading engagements and charges

    Mapping the structural diversity of C60 carbon clusters and their infrared spectra

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    The current debate about the nature of the carbonaceous material carrying the infrared (IR) emission spectra of planetary and proto-planetary nebulae, including the broad plateaus, calls for further studies on the interplay between structure and spectroscopy of carbon-based compounds of astrophysical interest. The recent observation of C60 buckminsterfullerene in space suggests that carbon clusters of similar size may also be relevant. In the present work, broad statistical samples of C60 isomers were computationally determined without any bias using a reactive force field, their IR spectra being subsequently obtained following local optimization with the density-functional-based tight-binding theory. Structural analysis reveals four main structural families identified as cages, planar polycyclic aromatics, pretzels, and branched. Comparison with available astronomical spectra indicates that only the cage family could contribute to the plateau observed in the 6-9 micron region. The present framework shows great promise to explore and relate structural and spectroscopic features in more diverse and possibly hydrogenated carbonaceous compounds, in relation with astronomical observations

    Proliferative and apoptotic pathways in the testis of quail coturnix coturnix during the seasonal reproductive cycle

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    The quail Coturnix coturnix is a seasonal breeding species, with the annual reproductive cycle of its testes comprising an activation phase and a regression phase. Our previous results have proven that the testicular levels of both 17β‐estradiol (E2) and androgens are higher during the reproductive period compared to the non‐reproductive period, which led us to hypothesize that estrogens and androgens may act synergistically to initiate spermatogenesis. The present study was, therefore, aimed to investigate the estrogen responsive system in quail testis in relation to the reproduction seasonality, with a focus on the molecular pathways elicited in both active and regressive quail testes. Western blotting and immunohistochemistry analysis revealed that the expression of ERα, which is the predominant form of estrogen receptors in quail testis, was correlated with E2 concentration, suggesting that increased levels of E2‐induced ERα could play a key role in the resumption of spermatogenesis during the reproductive period, when both PCNA and SYCP3, the mitotic and meiotic markers, respectively, were also increased. In the reproductive period we also found the activation of the ERK1/2 and Akt‐1 kinase pathways and an increase in second messengers cAMP and cGMP levels. In the non‐reproductive phase, when the E2/ERα levels were low, the inactivation of ERK1/2 and Akt‐1 pathways favored apoptotic events due to an increase in the levels of Bax and cytochrome C, with a consequent regression of the gonad

    INFLUENZA DELLA SALDATURA LASER SUL COMPORTAMENTO A MEMORIA DI FORMA A DUE VIE DI UNA LEGA NiTi

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    Nel presente lavoro è riportato lo studio del comportamento funzionale di un giunto saldato in lega NiTi a memoria di forma. In particolare, sono stati analizzati gli effetti della saldatura laser Nd:YAG sul comportamento a memoria di forma a due vie (Two Way Shape Memory Effect, TWSME) di una lega Ni- 51 at.% Ti, attraverso un confronto sistematico con i risultati relativi al materiale non saldato. Il TWSME è stato indotto nel materiale attraverso un opportuna procedura di training, che consiste nella ripetizione di cicli termomeccanici; successivamente, sono stati misurati i cicli di isteresi (temperatura-deformazione) caratteristici del TWSME. Sono stati valutati, inoltre, gli effetti del numero di cicli di training e delle deformazioni plastiche, che si generano nel materiale durante il processo di training, sul comportamento a memoria di forma del materiale. I risultati mostrano come il comportamento funzionale, e in particolare il TWSME, sia parzialmente preservato nel materiale saldato che, comunque, presenta valori di deformazioni plastiche maggiori rispetto al materiale base

    Deregulated expression of aurora kinases is not a prognostic biomarker in papillary thyroid cancer patients.

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    Abstract A number of reports indicated that Aurora-A or Aurora-B overexpression represented a negative prognostic factor in several human malignancies. In thyroid cancer tissues a deregulated expression of Aurora kinases has been also demonstrated, butno information regarding its possible prognostic role in differentiated thyroid cancer is available. Here, weevaluated Aurora-A and Aurora-B mRNA expression and its prognostic relevance in a series of 87 papillary thyroid cancers (PTC), with a median follow-up of 63 months. The analysis of Aurora-A and Aurora-B mRNA levels in PTC tissues, compared to normal matched tissues, revealed that their expression was either up-or down-regulatedin the majority of cancer tissues. In particular, Aurora-A and Aurora-B mRNA levels were altered, respectively, in 55 (63.2%) and 79 (90.8%) out of the 87 PTC analyzed. A significant positive correlation between Aurora-A and Aurora-B mRNAswas observed (p=0.001). The expression of both Aurora genes was not affected by the BRAF(V600E) mutation. Univariate, multivariate and Kaplan-Mayer analyses documented the lack of association between Aurora-A or Aurora-B expression and clinicopathological parameterssuch as gender, age, tumor size, histology, TNM stage, lymph node metastasis and BRAF status as well asdisease recurrences or disease-free interval. Only Aurora-B mRNA was significantly higher in T(3-4) tissues, with respect to T(1-2) PTC tissues. The data reported here demonstrate that the expression of Aurora kinases is deregulated in the majority of PTC tissues, likely contributing to PTC progression. However, differently from other human solid cancers, detection of Aurora-A or Aurora-B mRNAs is not a prognostic biomarker inPTC patients

    Effects of Moderate-Volume, High-Load Lower-Body Resistance Training on Strength and Function in Persons with Parkinson's Disease: A Pilot Study

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    Background. Resistance training research has demonstrated positive effects for persons with Parkinson's disease (PD), but the number of acute training variables that can be manipulated makes it difficult to determine the optimal resistance training program. Objective. The purpose of this investigation was to examine the effects of an 8-week resistance training intervention on strength and function in persons with PD. Methods. Eighteen men and women were randomized to training or standard care for the 8-week intervention. The training group performed 3 sets of 5–8 repetitions of the leg press, leg curl, and calf press twice weekly. Tests included leg press strength relative to body mass, timed up-and-go, six-minute walk, and Activities-specific Balance Confidence questionnaire. Results. There was a significant group-by-time effect for maximum leg press strength relative to body mass, with the training group significantly increasing their maximum relative strength (P < .05). No other significant interactions were noted (P > .05). Conclusions. Moderate volume, high-load weight training is effective for increasing lower-body strength in persons with PD

    The impact of delays to admission from the emergency department on inpatient outcomes

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    <p>Abstract</p> <p>Background</p> <p>We sought to determine the impact of delays to admission from the Emergency Department (ED) on inpatient length of stay (LOS), and IP cost.</p> <p>Methods</p> <p>We conducted a retrospective analysis of 13,460 adult (≥ 18 yrs) ED visits between April 1 2006 and March 30 2007 at a tertiary care teaching hospital with two ED sites in which the mode of disposition was admission to ICU, surgery or inpatient wards. We defined ED Admission Delay as ED time to decision to admit > 12 hours. The primary outcomes were IP LOS, and total IP cost.</p> <p>Results</p> <p>Approximately 11.6% (n = 1558) of admitted patients experienced admission delay. In multivariate analysis we found that admission delay was associated with 12.4% longer IP LOS (95% CI 6.6% - 18.5%) and 11.0% greater total IP cost (6.0% - 16.4%). We estimated the cumulative impact of delay on all delayed patients as an additional 2,183 inpatient days and an increase in IP cost of $2,109,173 at the study institution.</p> <p>Conclusions</p> <p>Delays to admission from the ED are associated with increased IP LOS and IP cost. Improving patient flow through the ED may reduce hospital costs and improve quality of care. There may be a business case for investments to reduce emergency department admission delays.</p
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