3,296 research outputs found

    Il Patrimonio Culturale tra esigenze e funzionalità quotidiane

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    La memoria vuole evidenziare come la politica che una nazione adotta sul patrimonio storico, ed in particolare sulle aree urbane, se adeguatamente correlata agli aspetti della Conservazione, della Valorizzazione, della Fruizione etc., puà migliorare, anche in modo significativo, lo sviluppo economico di un territorio che spesso, essendo depositario di specifiche caratteristiche, è Patrimonio non soltanto del singolo paese ma dell’intera Umanità. Una città accessibile a tutti i fruitori, dal turista, allo studioso, al portatore di handicap, etc., puà divenire fattore trainante di uno sviluppo culturale ed economico del territorio stesso. Per raggiungere questo scopo occorre proporsi l’obiettivo di offrire strutture, percorsi e attrezzature che ne consentano la piena godibilità a tutti, nel rispetto del contesto

    Recupero delle ex Officine Ducrot, oggi Cantieri culturali alla Zisa a Palermo

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    Il costante aumento della popolazione delle grandi città, ha indotto i comuni a reperire, spesso in maniera più o meno disordinata, nuove aree edificabili destinate, soprattutto, ad edilizia residenziale. Tale attività ha soventemente portato ad inglobare, all’interno delle città, particolari strutture come ad esempio, carceri, mercati ortofrutticoli, mercati ittici, agglomerati industriali, ecc. Nello specifico, le attività industriali, in seguito ad oculate pianificazioni, hanno spesso abbandonato gli antichi siti, per trasferirsi in aree industriali moderne e idoneamente attrezzate. La memoria, prendendo in esame le “Officine Ducrot”, realizzate alla fine dei XIX secolo a Palermo, vuole evidenziare come una corretta azione “politica” sul patrimonio di archeologia industriale, può rifunzionalizzare i siti rendendoli fruibili, consentendone una riappropriazione da parte della società e, al contempo, fare in modo che possano divenire fonte di sviluppo culturale ed economico del territorio stesso. Per raggiungere questo scopo occorre porsi l’obiettivo di offrire strutture, percorsi e attrezzature che ne consentano la piena godibilità a tutti, nel rispetto del contest

    Selective gold and palladium adsorption from standard aqueous solutions

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    The intensive exploitation of resources on a global level has led to a progressive depletion of mineral reserves, which were proved to be insufficient to meet the high demand for high-technological devices. On the other hand, the continuous production of Waste from Electrical and Electronic Equipment (WEEE) is causing serious environmental problems, due to the complex composition of WEEE, which makes the recycling and reuse particularly challenging. The average metal content of WEEE is estimated to be around 30% and varies depending on the manufacturing period and brand of production. It contains base metals and precious metals, such as gold and palladium. The remaining 70% of WEEEs is composed of plastics, resins, and glassy materials. The recovery of metals from WEEEs is characterized by two main processes well represented by the literature: Pyrometallurgy and hydrometallurgy. Both of them require the pre-treatment of WEEEs, such as dismantling and magnetic separation of plastics. In this work, the selective adsorption of precious metals has been attempted, using copper, gold, and palladium aqueous solutions and mixtures of them. A screening on different adsorbent materials such as granular activated carbons and polymers, either as pellets or foams, has been performed. Among these, PolyEther Block Amide (PEBA) was elected as the most performing adsorbent in terms of gold selectivity over copper. Spent PEBA has been then characterized using scanning electron microscope, coupled with energy dispersive spectroscopy, demonstrating the predominant presence of gold in most analyzed sites, either in the pellet or foam form

    Task Scheduling with RT Constraints

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    This paper addresses the problem of scheduling reactive realtime transactions (task groups) implementing a network of extended Finite State Machines communicating asynchronously. Task instances are..

    Hepatotoxicity induced by greater celandine (Chelidonium majus L.): a review of the literature

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    The available literature assessing Chelidonium majus L. (CM) hepatotoxicity potential, and its risk to benefit assessment has been reviewed in this paper. Identification of significant scientific literature was performed via the following research databases: Cochrane Central, Google Scholar, EMBASE, Medline, Science Direct, Scopus, Web of Science, using the following keywords: "Chelidonium majus", "greater celandine", "Hepatotoxicity", "Liver" "Injury", "Toxicity" individually investigated and then again in association. CM named also greater celandine, swallow-wort, or bai-qu-cai (Chinese), has been used for a long time in traditional Chinese medicine and phytotherapy. Its extracts have been claimed to display a wide variety of biological activities: antimicrobial, anti-inflammatory, spasmolytic, antineoplastic, hepatoprotective, and analgesic. Moreover, herbal medicine suggests this plant have numerous additional effects which have not yet been scientifically evaluated, such as antitussive, diuretic, and eye-regenerative. However, despite its claimed hepatoprotective effects, several hepatotoxicity cases have been reported to be probably or highly probably connected with CM exposure, after their evaluation through liver-targeted causality assessment methods. CM hepatotoxicity has been defined as a distinct form of herb-induced liver injury (HILI), due to an idiosyncratic reaction of the metabolic type. This evidence has to be considered in relationship with the absence of considerable benefits of CM therapy. Therefore, the risk to benefit ratio of the use of herbal products containing greater celandine can actually be considered as negative

    Selective leaching of precious metals from electrical and electronic equipment through hydrometallurgical methods

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    The rapid human evolution has improved the quality of our lives through the use of technology. This not only resulted in increased raw materials extraction but also in the production of a worrying amount of electronic wastes. Indeed, in 2019 worldwide production of Electronic and Electric Equipment Waste (WEEE) was worth 50 million tons, causing several disadvantages such as the reduced space in landfills and massive shipping to countries with less restrictive regulations. On the other side, the billionaire electrical devices market is causing a significant increase in Precious Metals (PM) demand. Nowadays, the economic importance of PMs is as high as their supply risk. The answer to this problem consists of finding selective methods to extract and raffinate precious metals from disposed WEEE. On average, WEEEs contain around 30 % of plastics, 30 % ceramics, and 40 % metals; among these only around 0.1 % is characterized by PMs, such as gold, silver, rhodium, platinum, and palladium. The separation of PMs from other non-precious components is generally obtained using pyrometallurgy, which consists of fusing the wastes at temperatures up to 1500 ÷ 1700 °C. However, this method produces toxic gaseous byproducts and implies high energy costs. A possible alternative is given by hydrometallurgical processes, consisting of leaching the WEEE with solutions containing acids and oxidants at temperatures lower than 100°C. One of the main issues of the hydrometallurgical process is to leach copper and other non-precious base-metals selectively while keeping PMs in the solid-state. In this work, we report preliminary results of equilibrium and kinetic leaching tests in a well-stirred batch reactor, aimed at the optimization of the main operating parameters of a hydrometallurgical process for selective leaching of copper and other base-metals from Wasted Printed Circuit Boards (WPCBs). In particular, experiments have been carried out at different HCl and NaCl concentrations of the leaching solutions, exploring also the effect of temperature variation (20, 50, and 70 °C)

    a mathematical description accounting for the superfluous hydrogen evolution and the inductive behaviour observed during electrochemical measurements on magnesium

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    Abstract When electrochemical techniques are used to probe the surface of corroding magnesium with the aim of obtaining quantitative information on the corrosion process, two peculiarities are generally observed: i) with anodic polarization, the rate of hydrogen evolution increases instead of decreasing and ii) during electrochemical impedance spectroscopy measurements, an inductive contribution is often observed at the low-frequency end of the spectra. The presence of these two phenomena clearly has an impact on the methodology that should be applied to correctly estimate corrosion rates from electrochemical data. The aim of this work is to provide a general mathematical description of the corroding magnesium surface that, under minimal a priori assumptions regarding the reaction kinetics, can account simultaneously for both superfluous hydrogen evolution and inductive response. The mathematical results are consistent with the suggestion that the superfluous hydrogen evolution is mainly related to the increase of the surface of the active corrosion front during anodic polarization. Further, the obtained results show that the inductive response is expected when, at the corrosion front, oxidation of magnesium proceeds faster than hydrogen evolution

    Cross-Layer Early Reliability Evaluation for the Computing cOntinuum

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    Advanced multifunctional computing systems realized in forthcoming technologies hold the promise of a significant increase of the computational capability that will offer end-users ever improving services and functionalities (e.g., next generation mobile devices, cloud services, etc.). However, the same path that is leading technologies toward these remarkable achievements is also making electronic devices increasingly unreliable, posing a threat to our society that is depending on the ICT in every aspect of human activities. Reliability of electronic systems is therefore a key challenge for the whole ICT technology and must be guaranteed without penalizing or slowing down the characteristics of the final products. CLERECO EU FP7 (GA No. 611404) research project addresses early accurate reliability evaluation and efficient exploitation of reliability at different design phases, since these aspects are two of the most important and challenging tasks toward this goal

    Long-term treatment with high-dose of sildenafil in a thalassemic patient with pulmonary hypertension

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    We report a case of a 37-years-old man, affected by thalassemia major, hypogonadotropic hypogonadism, chronic HCV-hepatitis, diabetes mellitus, severe osteoporosis, prior septic pulmonary embolism and pulmonary artery hypertension was performed a long-term treatment with highdose of sildenafil (120 mg/die) with reduction of pulmonary arterial systolic pressure and of the dyspnea
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