619 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

    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

    Cover crops and manure combined with commercial fertilizers differently affect yield and quality of processing tomato (Solanum lycopersicum l.) organically grown in puglia

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    Nitrogen is crucial for the productivity of agricultural systems, although there is a growing demand for alternative cultural practices that reduce the off-farm inputs of this fertilizer. Cover crops provide a suite of services; among these, they can affect soil nitrogen content. In addition, the use of manure can contribute to a decrease in nitrogen loads from external inputs. The aim of this study was to evaluate, in processing tomato grown under an organic system, the combined use of cover crops (i.e., Vicia faba var. minor, Triticum aestivum, and Raphanus sativus) or cattle manure, with reduced rates of commercial nitrogen fertilizers. The yield and some important qualitative characteristics of the tomato fruits were considered. V. faba was able to enhance the effects of the external input of nitrogen with respect to the yield. External inputs increased tocopherol content with respect to the control but only when it was integrated with manure. The content of carotenoids was not affected by commercial fertilizer alone; however, when it was supplied in addition to cattle manure or incorporation of R. sativus, a decrease in ÎČ-carotene was observed. Moreover, lycopene also decreased when T. aestivum or R. sativus were used as cover crops. We conclude that the sowing of nitrogen-fixing cover crops or the use of manure are good strategies for combining internal and external inputs for the sustainable production of processing tomato

    ATLAS RPC Quality Assurance results at INFN Lecce

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    The main results of the quality assurance tests performed on the Resistive Plate Chamber used by the ATLAS experiment at LHC as muon trigger chambers are reported and discussed. Since July 2004, about 270 RPC units has been certified at INFN Lecce site and delivered to CERN, for being integrated in the final muon station of the ATLAS barrel region. We show the key RPC characteristics which qualify the performance of this detector technology as muon trigger chamber in the harsh LHC enviroments. These are dark current, chamber efficiency, noise rate, gas volume tomography, and gas leakage.Comment: Comments: 6 pages, 1 table, 9 figures Proceedings of XXV Physics in Collision-Prague, Czech Republic, 6-9 July 200

    Effects of weed control practices on plant diversity in a homogenous olive-dominated landscape (South-east of Italy)

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    Olive groves represent an important economic, agro-ecological, and cultural resource in the Mediterranean Basin. Weed management plays a fundamental role in their sustainable management. The aim of this work was to characterize and assess the plant diversity associated with different weed control practices, in a homogeneous olive-dominated landscape in the South-East of Italy. Sixty-five vegetation plots were sampled in orchards treated with different weed control practices: mowing, tillage, and use of chemical herbicides. The multi-response permutation procedure was used to test the hypothesis of no difference among the treatments. The relationships between plots were visualized by means of non-metric multidimensional scaling ordination. A generalized linear mixed model was used to analyze the relationships between weed control practices and life forms, chorotypes, and diversity indexes. The results showed that the three weed control practices determined slightly different plant communities. Chemically weeded orchards showed an impoverished floristic composition and the lowest diversity, whereas mowing and tillage yielded similar values. These latter two treatments differed for the percentages of hemicryptophytes and therophytes. Moreover, different from other studies, we did not find plant species of particular concern for biodiversity conservation. We hypothesize that this result is due to the monotonous structure of the agro-landscape we investigated, where natural elements are almost lacking. From this point of view, a correct management of agro-districts should consider both the agronomic practices at the level of the individual olive groves and the structure of the agro-landscape

    A single liver metastasis from pleural biphasic mesothelioma

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    Virtually any malignancy can metastasize to the liver. Large solitary metastases are rare and can be difficult to distinguish from primary tumors. Malignant mesothelioma is often considered as a locally invasive cancer but tumor dissemination to extra-thoracic sites is possible, and the liver can be involved. Herein, we present a rare case of pleural mesothelioma with a solitary large liver metastasis diagnosed postmortem in a ninety-two-year-old man with 35 years of exposure to asbestos. Results of immunohistochemical staining of the pleural and liver tumor were similar, both positive for low-molecular weight keratins, calretinin, vimentin, and podoplanin, and negative for Claudin-4, TTF1, CEA, BerEP4, CK7, CK19, CK20, BAP1, Hep Par1, p40, and WT1. Fluorescent in-situ hybridization (FISH) for p16/CDKN2A was also performed and a homozygous deletion was detected in both tumors, supporting the diagnosis of mesothelioma. Reporting this case, we would like to point out that extra-thoracic dissemination from pleural mesothelioma, even if exceptional, can occur. In cases where differential diagnoses are challenging, the value of ancillary techniques and a practical approach to diagnostic work-up is of primary importance

    Hpv-negative cervical cancer: A narrative review

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    Cervical cancer (CC) is the fourth most frequent cancer in women worldwide. HPV infection is associated with the majority of CC cases, but a small proportion of CCs actually test negative for HPV. The prevalence of HPV among CC histotypes is very different. It has been suggested that HPV-negative CC may represent a biologically distinct subset of tumors, relying on a distinct pathogenetic pathway and carrying a poorer prognosis, than HPV-positive CCs. Although, the discordance in terms of sensitivity and specificity between different HPV tests as well as the potential errors in sampling and storing tissues may be considered as causes of false-negative results. The identification of HPV-negative CCs is essential for their correct management. The aim of this narrative review is to summarize the clinical and pathological features of this variant. We also discuss the pitfalls of different HPV tests possibly leading to classification errors

    ATLAS RPC Cosmic Ray Teststand at INFN Lecce

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    We describe the design and functionality of the cosmic ray teststand built at INFN Lecce for ATLAS RPC quality control assurance.Comment: XXIV Physics in Collisions Conference (PIC04), Boston, USA, June 2004, 3 pages, LaTex, 2 eps figures. MONP0

    A rare case of posterior fossa tumor and central precocious puberty: Case presentation and review of the literature

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    Central precocious puberty (CPP) is a condition that causes early gonadotropin-dependent sexual development; CPP is idiopathic in girls in most cases, whereas more than 50% of boys have an identifiable etiology. We conducted a qualitative systematic review following the ENTREQ (enhancing transparency in reporting the synthesis of qualitative research) framework. A search was made in MEDLINE/Pubmed and MeSH Database using the terms “precocious puberty” AND “brain tumor” OR “posterior fossa tumor” OR “cerebellar tumor” OR “infratentorial tumor”, iden-tifying five cases of pediatric patients with infratentorial tumors and CPP and a case of cerebellar ganglioglioma without hypothalamic−pituitary−gonadal axis involvement and/or intracranial hypertension. Our work highlights the importance of a multidisciplinary approach and extensive central nervous system imaging for patients presenting with CPP in order to detect possible tumor association. Moreover, we believe that this manuscript could contribute to stimulate other research because the exact mechanism of CPP in infratentorial brain lesions has not been understood yet

    Is the first of the two born saved? A rare and dramatic case of double placental damage from SARS-CoV-2

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    The current coronavirus pandemic has affected, in a short time, various and different areas of medicine. Among these, the obstetric field has certainly been touched in full, and the knowledge of the mechanisms potentially responsible for placental damage from SARS-CoV-2 occupy a certain importance. Here we present here a rare case of dichorionic twins born at 30 weeks and 4 days of amenorrhea, one of whom died in the first few hours of life after placental damages potentially related to SARS-CoV-2. We also propose a brief review of the current literature giving ample emphasis to similar cases described
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