690 research outputs found

    Renewable sources urban cells microgrid. A case study

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    Nowadays, microgrid technologies play a relevant role in the research field as well as in the commercial market. The opportunity to provide electricity in wide areas without using centralized electrical infrastructure networks is a reliable key for achieving the European Union sustainability goals. In this regard, the proposed research aims at describing an electric microgrid configuration powered by a photovoltaic system, supplying three school buildings located in the center of Italy. Additionally, the resilience theme is deeply investigated, analyzing the use of an emergency generator system (EGS) in case of electric grid blackouts. MATLAB/Simulink was chosen to simulate the users’ energy demand as well as to calculate the microgrid performance. Results show that almost the total consumption of the microgrid is covered by the photovoltaic system, and the use of an EGS allows energy resilience and moderate economic savings for the communit

    Development of thermoplastic starch (TPS) including leather waste fragments

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    A thermoplastic starch (TPS) material is developed, based on corn starch plasticized with glycerol and citric acid in a 9:3:1 ratio and further bonded with isinglass and mono-and diglycerides of fatty acids (E471). In TPS, leather fragments, in the amount of 7.5 15 or 22.5 g/100 g of dry matter, were also introduced. The mixture was heated at a maximum temperature of 80 °C, then cast in an open mold to obtain films with thickness in the range 300 ± 50 microns. The leather fragments used were based on collagen obtained from production waste from shoemaking and tanned with tannins obtained from smoketree (Rhus cotinus), therefore free from chromium. Thermogravimetric (TGA) tests suggested that material degradation started at a temperature around 285 °C, revealing that the presence of leather fragments did not influence the occurrence of this process in TPS. Tensile tests indicated an increase in tensile properties (strength and Young's modulus) with increasing leather content, albeit coupled, especially at 22.5 wt%, with a more pronounced brittle behavior. Leather waste provided a sound interface with the bulk of the composite, as observed under scanning electron microscopy. The production process indicated a very limited degradation of the material after exposure to UV radiation for eight days, as demonstrated by the slight attenuation of amide I (collagen) and polysaccharide FTIR peaks. Reheating at 80 °C resulted in a weight loss not exceeding 3%

    Magnetic losses in Si-Fe alloys for avionic applications

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    This paper presents an experimental analysis of the rotational power losses of the magnetic materials of transformers, motors and actuators used in avionic environment. A large frequency range is investigated using a suitable experimental test frame developed to measure the power losses for a circular magnetization. The results about different silicon iron alloys with different textures and thickness are considered and compared

    Water resource management through systemic approach: The case of Lake Bracciano

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    Today natural water resources are becoming scarce, both due to global climate change but also due to irresponsible behaviour of human beings. Lakes are among the most delicate aquatic systems due to their limited size. The objective of this paper is to propose a System Dynamics model, employed in a real case study regarding the city of Rome and one of its water reserves, the Bracciano Lake, for the evaluation of different strategies and policies to reduce environmental impacts, considering different climatic and context scenarios. The results indicate that, as the system is currently exposed to a high risk of ecological disaster, the situation might worsen, and the disaster effectively happen. Simulation models may help agencies and administrations to explore policies and find solutions to address this fundamental problem, that may become even worst over the next years, given the potential severe consequences deriving from the current global warming trends

    SUGAMMADEX versus neostigmine after ROCURONIUM continuous infusion in patients undergoing liver transplantation

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    Background: Rapid neuromuscular block reversal at the end of major abdominal surgery is recommended to avoid any postoperative residual block. To date, no study has evaluated sugammadex performance after rocuronium administration in patients undergoing liver transplantation. This is a randomized controlled trial with the primary objective of assessing the neuromuscular transmission recovery time obtained with sugammadex versus neostigmine after rocuronium induced neuromuscular blockade in patients undergoing orthotopic liver transplantation. Methods: The TOF-Watch SX\uae, calibrated and linked to a portable computer equipped with TOF-Watch SX Monitor Software\uae, was used to monitor and record intraoperative neuromuscular block maintained with a continuous infusion of rocuronium. Anaesthetic management was standardized as per our institution's internal protocol. At the end of surgery, neuromuscular moderate block reversal was obtained by administration of 2 mg/kg of sugammadex or 50 mcg/kg of neostigmine (plus 10 mcg/kg of atropine). Results: Data from 41 patients undergoing liver transplantation were analysed. In this population, recovery from neuromuscular block was faster following sugammadex administration than neostigmine administration, with mean times\ub1SD of 9.4 \ub1 4.6 min and 34.6 \ub1 24.9 min, respectively (p < 0.0001). Conclusion: Sugammadex is able to reverse neuromuscular block maintained by rocuronium continuous infusion in patients undergoing liver transplantation. The mean reversal time obtained with sugammadex was significantly faster than that for neostigmine. It is important to note that the sugammadex recovery time in this population was found to be considerably longer than in other surgical settings, and should be considered in clinical practice. Trial registration: ClinicalTrials.gov NCT02697929 (registered 3rd March 2016)

    Assessment of body fluid balance and voluntary drinking in ultimate players during a match.

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    AIM: Ultimate is a sport played by hundreds of thousands of people in more than 42 countries; however, it is still mainly known as a recreational more than a team sport, and further studies are needed to define its physical load. Particularly, since no studies relating Ultimate to hydration have been performed, we aimed to determine body fluid balance, voluntary water intake and the most reliable method for assessing the hydration status of players after a typical 80-minute Ultimate match. METHODS: bioimpedance, urine specific gravity and body mass changes to asses the hydration level of the players were measured. RESULTS: It was observed that not all of the methods are adequate to determine dehydration in Ultimate players, and that measurement of body mass changes represents a reliable and accurate technique. CONCLUSIONS: These findings demonstrate that ultimate as an intense sport that can induce significant fluid loss, which is not always replaced by individual drinking

    The XXL Survey VIII: MUSE characterisation of intracluster light in a z\sim0.53 cluster of galaxies

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    Within a cluster, gravitational effects can lead to the removal of stars from their parent galaxies. Gas hydrodynamical effects can additionally strip gas and dust from galaxies. The properties of the ICL can therefore help constrain the physical processes at work in clusters by serving as a fossil record of the interaction history. The present study is designed to characterise this ICL in a ~10^14 M_odot and z~0.53 cluster of galaxies from imaging and spectroscopic points of view. By applying a wavelet-based method to CFHT Megacam and WIRCAM images, we detect significant quantities of diffuse light. These sources were then spectroscopically characterised with MUSE. MUSE data were also used to compute redshifts of 24 cluster galaxies and search for cluster substructures. An atypically large amount of ICL has been detected in this cluster. Part of the detected diffuse light has a very weak optical stellar component and apparently consists mainly of gas emission, while other diffuse light sources are clearly dominated by old stars. Furthermore, emission lines were detected in several places of diffuse light. Our spectral analysis shows that this emission likely originates from low-excitation parameter gas. The stellar contribution to the ICL is about 2.3x10^9 yrs old even though the ICL is not currently forming a large number of stars. On the other hand, the contribution of the gas emission to the ICL in the optical is much greater than the stellar contribution in some regions, but the gas density is likely too low to form stars. These observations favour ram pressure stripping, turbulent viscous stripping, or supernovae winds as the origin of the large amount of intracluster light. Since the cluster appears not to be in a major merging phase, we conclude that ram pressure stripping is the most plausible process that generates the observed ICL sources.Comment: Accepted in A&A, english enhanced, figure location different than in the A&A version due to different style files, shortened abstrac
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