191 research outputs found

    Segond's fracture: a biomechanical cadaveric study using navigation

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    Background Segond’s fracture is a well-recognised radiological sign of an anterior cruciate ligament (ACL) tear. While previous studies evaluated the role of the anterolateral ligament (ALL) and complex injuries on rotational stability of the knee, there are no studies on the biomechanical effect of Segond’s fracture in an ACL deficient knee. The aim of this study was to evaluate the effect of a Segond’s fracture on knee rotation stability as evaluated by a navigation system in an ACL deficient knee. Materials and methods Three different conditions were tested on seven knee specimens: intact knee, ACL deficient knee and ACL deficient knee with Segond’s fracture. Static and dynamic measurements of anterior tibial translation (ATT) and axial tibial rotation (ATR) were recorded by the navigation system (2.2 OrthoPilot ACL navigation system B. Braun Aesculap, Tuttlingen, Germany). Results Static measurements at 30 showed that the mean ATT at 30 of knee flexion was 5.1 ± 2.7 mm in the ACL intact condition, 14.3 ± 3.1 mm after ACL cut (P = 0.005), and 15.2 ± 3.6 mm after Segond’s fracture (P = 0.08). The mean ATR at 30 of knee flexion was 20.7 ± 4.8 in the ACL intact condition, 26.9 ± 4.1 in the ACL deficient knee (P[0.05) and 30.9 ± 3.8 after Segond’s fracture (P = 0.005). Dynamic measurements during the pivot-shift showed that the mean ATT was 7.2 ± 2.7 mm in the intact knee, 9.1 ± 3.3 mm in the ACL deficient knee(P = 0.04) and 9.7 ± 4.3 mm in the ACL deficient knee with Segond’s fracture (P = 0.07). The mean ATR was 9.6 ± 1.8 in the intact knee, 12.3 ± 2.3 in the ACL deficient knee (P[0.05) and 19.1 ± 3.1 in the ACL deficient knee with Segond’s lesion (P = 0.016). Conclusion An isolated lesion of the ACL only affects ATT during static and dynamic measurements, while the addition of Segond’s fracture has a significant effect on ATR in both static and dynamic execution of the pivot-shift test, as evaluated with the aid of navigation

    Analysis of the existing barriers for the market development of power to hydrogen (P2H) in Italy

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    New technological solutions are required to control the impact of the increasing presence of renewable energy sources connected to the electric grid that are characterized by unpredictable production (i.e., wind and solar energy). Energy storage is becoming essential to stabilize the grid when a mismatch between production and demand occurs. Among the available solutions, Power to Hydrogen (P2H) is one of the most attractive options. However, despite the potential, many barriers currently hinder P2H market development. The literature reports general barriers and strategies to overcome them, but a specific analysis is fundamental to identifying how these barriers concretely arise in national and regional frameworks, since tailored solutions are needed to foster the development of P2H local market. The paper aims to identify and to analyze the existing barriers for P2H market uptake in Italy. The paper shows how several technical, regulatory and economic issues are still unsolved, resulting in a source of uncertainty for P2H investment. The paper also suggests possible approaches and solutions to address the Italian barriers and to support politics and decision-makers in the definition and implementation of the national hydrogen strategy

    Techno-economic assessment of the innovative ejectors plant technology for sediment management in harbours

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    Purpose: The paper aims to show the monitoring results of an innovative technology, the ejectors plant, tested in the MARINAPLAN PLUS LIFE project framework for sustainable sediment management in harbours. Materials and methods: A monitoring plan has been designed to evaluate the technical, economic and environmental impact of the ejectors plant demonstrator for 15 months, located in Cervia (Italy). In particular, the demonstrator’s effectiveness and efficiency have been assessed to determine the yearly operation and maintenance costs. Results and discussion: The techno-economic analysis shows promising results in terms of efficacy and efficiency of the ejectors plant. The ejectors plant guaranteed navigability for the whole period of operation with a yearly cost reduction compared with traditional dredging. Conclusions: The innovative technology promoted by the MARINAPLAN PLUS LIFE project is a promising solution to manage sedimentation in harbours through a cost-effective and a low environmental impact technology. The monitoring actions validated the technology fully and demonstrated its efficacy and sustainability, highlighting the further improvements needed

    Experimental measurements of the new gas smart meters' current discharges to suggest improvement solutions for power supply battery life extension

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    Several reasons justified introducing the smart metering concept in the gas distribution sector and supporting its digitalization. Specifically, among their functionalities, the new smart meters would improve the ability to identify abnormal consumption or malfunctions in the gas grid or at customers’ appliances as soon as possible, improving the gas distribution system’s safety performance. The installation and operation of gas smart meters result in a significant amount of data to be managed. Specifically, gas consumption, the supply pressure, and information about the status of the device, such as the events that occurred, are some of the data communicated daily to the gas Distribution System Operators (DSOs). However, despite the advantages, some drawbacks were first experienced by the DSOs, requiring unplanned intervention and increasing the operative costs. Among these, the discharge of the batteries sooner than expected increases the operative costs. In fact, due to ATEX safety aspects, the smart meters are not directly connected to the electric grid but they are powered by batteries that have to be replaced only by authorized personnel. The present paper reports the preliminary results obtained during an experimental campaign to investigate the impact of data communication on the battery lifetime. Specifically, four communication protocols that differ in the number of data strings and the communication frequency were compared, and preliminary conclusions were given

    The future of sovereignty in multilevel governance Europe: a constructivist reading

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    Multilevel governance presents a depiction of contemporary structures in EU Europe as consisting of overlapping authorities and competing competencies. By focusing on emerging non-anarchical structures in the international system, hence moving beyond the conventional hierarchy/anarchy dichotomy to distinguish domestic and international arenas, this seems a radical transformation of the familiar Westphalian system and to undermine state sovereignty. Paradoxically, however, the principle of sovereignty proves to be resilient despite its alleged empirical decline. This article argues that social constructivism can explain the paradox, by considering sovereign statehood as a process-dependent institutional fact, and by showing that multilevel governance can feed into this process

    A New Geographic Information System (GIS) Tool for Hydrogen Value Chain Planning Optimization: Application to Italian Highways

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    Optimizing the hydrogen value chain is essential to ensure hydrogen market uptake in replacing traditional fossil fuel energy and to achieve energy system decarbonization in the next years. The design of new plants and infrastructures will be the first step. However, wrong decisions would result in temporal, economic losses and, in the worst case, failures. Because huge investments are expected, decision makers have to be assisted for its success. Because no tools are available for the optimum design and geographical location of power to gas (P2G) and power to hydrogen (P2H) plants, the geographic information system (GIS) and mathematical optimization approaches were combined into a new tool developed by CNR-ITAE and the University of Bologna in the SuperP2G project, aiming to support the interested stakeholders in the investigation and selection of the optimum size, location, and operations of P2H and P2G industrial plants while minimizing the levelized cost of hydrogen (LCOH). In the present study, the tool has been applied to hydrogen mobility, specifically to investigate the conversion of the existing refuelling stations on Italian highways to hydrogen refuelling stations (HRSs). Middle-term (2030) and long-term (2050) scenarios were investigated. In 2030, a potential demand of between 7000 and 10,000 tons/year was estimated in Italy, increasing to between 32,600 and 72,500 tons/year in 2050. The optimum P2H plant configuration to supply the HRS was calculated in different scenarios. Despite the optimization, even if the levelized cost of hydrogen (LCOH) reduces from 7.0-7.5 euro/kg in 2030 to 5.6-6.2 euro/kg in 2050, the results demonstrate that the replacement of the traditional fuels, i.e., gasoline, diesel, and liquefied petroleum gases (LPGs), will be disadvantaged without incentives or any other economic supporting schemes

    Distraction Arthroplasty for Basal Thumb Osteoarthritis: 10-Year Follow-Up

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    Purpose: Trapeziectomy has frequently been used to treat basal thumb osteoarthritis. However, complications, such as shortening of the thumb ray and reduced mobility and strength, can occur. The aim of this study was to present a 10-year follow-up of distraction arthroplasty without trapeziectomy. Methods: Fifteen patients were followed for a mean of 121 months (range, 121-124 months). Subjective outcomes were evaluated with the Disabilities of the Arm, Shoulder, and Hand questionnaire, while the pain intensity was assessed with a Visual Analog Scale both before surgery and at the end of follow-up. Objective outcomes were obtained using the Kapandji score and an assessment of grip and pinch strength. Preoperative and final postoperative x-rays were obtained to evaluate metacarpal subsidence and progression of trapezial-metacarpal joint arthritis. Results: The Visual Analog Scale score was reduced from 9.4 ± 0.5 before surgery to 2.5 ± 1 at follow-up. The mean Disabilities of the Arm, Shoulder, and Hand questionnaire score was 75.6 ± 12.6 before surgery and 16.9 ± 4 at 10 years. Hand grip strength of the operated side (26 ± 5.5 kg) achieved 95% of functionality compared to the opposite side, while key pinch strength (6.4 ± 1.6 kg) reached 93%. A Kapandji opposition score of 10 points was found in 12 patients, a score of 9 was found in 1, and a score of 8 was found in 2. Conclusions: Distraction arthroplasty of the trapeziometacarpal joint ensures good results in long-term follow-up, when performed in patients with stage I-II basal thumb osteoarthritis. Type of study/level of evidence: Therapeutic IV
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