81 research outputs found

    Modelli di prestazione ed allenamento speciale della velocitĂ  in atletica leggera

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    Material flow analysis of aluminium, copper, and iron in the EU-28

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    The EC Raw Materials System Analysis (MSA) was carried out in 2015 for 28 materials . The MSA study investigates the flows of materials through the EU economy in terms of entry into the EU, flows through the economy, stock accumulation, and end-of-life management, e.g., through disposal or recovery in the EU-28. The MSA study is a follow-up of the “Study on Data Needs for a Full Raw Materials Flow Analysis” , launched by the European Commission in 2012 within the context of the European Raw Materials Initiative’s (RMI) strategy. This strategy, which is a part of the Europe 2020’s strategy for smart, sustainable, and inclusive growth, aims at securing and improving access to raw materials for the EU. The MSA is a key building block of the European Union Raw Materials Knowledge Base (EURMKB). MSAs are an important data provider for a variety of raw material policy knowledge needs, as also reflected in the Raw Materials Information System (RMIS). The RMIS aims to support the broad range of EU policy knowledge needs of, e.g., the EU Raw Materials (RM) Scoreboard, EU Critical Raw Materials (CRM) assessment, and EU trade negotiations. In addition, it also aims to support broader coordination beyond these needs of other EU level data and information on raw materials. For both of these EUKBRM/RMIS roles, MSA is a vital backbone. The MSA data sets contain key, material specific data and information that will support the development of a database for the RMIS. However, currently only 28 MSA studies exist (mostly for CRMs) which are quickly becoming outdated. So far, no MSA studies exist for some of the major metals (e.g., iron, copper, aluminium, zinc, or nickel) which are important to the EU economy, e.g., due to the large quantities in which find use as well as due to their use in special application, e.g., as alloying elements. Against this background, this report presents, firstly, detailed MSA studies for aluminium (Al), copper (Cu), and iron (Fe) and discusses, secondly, possibilities for future MSA update and maintenance in the RMIS. Overall, the results show that the EU-28 has a well-established industrial chain for all the three metals covering the major value chain steps (from extraction to end-of-life). However, modest natural deposits make the region strongly dependent on imports to meet the domestic demand of primary material . Only a small fraction of total primary metal input to processing in the EU-28 is supplied from domestic extraction ranging from 10% (Al) to 13% (Fe). Demand-supply dynamics and product lifetime determine the accumulation of materials as in-use stocks and scrap generation at end-of-life. Iron, aluminium, and copper are used in large quantities (compared to other metals) and their major application segments have relatively long in-use lifetimes (e.g., 50-75 years for building and construction). In-use stock for the three metals in EU-28 were estimated at about 5,300 Tg for iron (or around 10 t per capita), 132 Tg for aluminium (around 260 kg per capita), 73 Tg for copper (around 140 kg per capita). A consolidated recycling industry supplements primary supply of aluminium, copper and iron with inputs from secondary sources (i.e., new scrap and old scrap ). In particular, old scrap recycling performance attests respectable end-of-life recycling rates (EOL-RR) for the three metals (i.e., 69% aluminium, 61% copper, 75% iron), but they are still far from “perfect” recycling. In addition, not all old scrap collected for recycling is processed in the EU-28, with the region being a net-exporter of secondary material. Material loss in products at end-of-life and net-exports of secondary material forms constraint the closure of material cycles and prevent the implementation of a circular economy in the EU-28 requiring the adoption of resource efficiency strategies priority. Because of its system-wide perspective on raw materials issues (encompassing all life-cycle stages of a raw material), the MSA provides an overarching data structure that could be based inside the RMIS database (DB) core to collect, store, and provide data also for other policy knowledge needs (i.e., EU CRM assessment, Circular Economy Monitoring, Trade, Minventory, RM Scoreboard). Flows/stocks parameters of the MSA can also be important to satisfy knowledge needs that may arise as a result of future policy needs, e.g., through resilience, determining urban stocks, and other emerging issues. Equally, complete MSAs can help in the quality assurance of the underlying mass balance/data and increasing harmonization of the various data sources – which cannot be guaranteed if only a partial picture exists. Results from an assessment of data overlaps between MSA and other policy-related outputs show that current policy knowledge needs often require data on various flows related to the early stages of a raw material’s life-cycle. For example, a total of 12 flows (out of 40 in total) of the MSA are also required for the 2017 CRM assessment. Data on secondary raw materials are essential for current circular economy monitoring, but generally difficult to obtain without MSAs. Possibilities for MSA update and maintenance range from partial data updates (harvesting data synergies with current policy-related outputs, e.g., the CRM assessment, Scoreboard, and Trade module in RMIS) to carrying out full/systematic MSAs for most candidate materials of the CRM assessment (through European Commission (EC) internal research projects and outsourcing via external contracts).JRC.D.3-Land Resource

    Shot Put: Which Role for Kinematic Analysis?

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    Background: To understand the technical differences between shot putters of different ages, this study compared biomechanical parameters of the best senior and youth Italian athletes and then to world‐class athletes (WC) assessed in previous investigations. Methods: The best throws of 16 shot putters [8 Senior (SG) and 8 Youth (YG)] were recorded by video cameras during the Italian Championships’ final and considered for 3D reconstruction. The following parameters were measured: time of the different throwing phases, shot trajectory, release angle, release velocity, and the force produced in the final phase. Results: Significant differences between SG and YG were detected in second single support time (p = 0.015), support time (p = 0.007), total time (p = 0.028) and in the force produced during the final phase (p < 0.001). A lower level of force, release speed, and a shorter shot trajectory during the double support were detected in SG compared to WC. Conclusions: The present study showed that, although the technical performance of all athletes was similar, some differences exist between YG and SG. The gap between the groups may be partially explained by the difference in force produced in the final phase of the throw and by a different interpretation of the technique

    EFFECTS OF FATIGUE ON KINEMATICS AND SHOCK ATTENUATION DURING DOWNHILL TRAIL RUNNING

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    This study assessed the effects of a competitive trail run on running kinematics and shock attenuation in well-trained trail runners. Nine male runners performed a simulated short trail running race. Prior and 5-min after the race, participants completed a 290-m downhill run at pre-determined preferred speed. Inertial measurement units were used to assessselected kinematic parameters. The contact time showed a moderate increase in the fatigued condition (pre: 0.215 (0.024) s vs. post: 0.226 (0.219) s; p2vs. post: 49.1 (11.9) m/s2; p=0.038; d=0.56), while peak tibial acceleration and shock attenuation showed no change (p\u3e0.05). These findings confirm that running-induced fatigue impacts running kinematics, although shock attenuation was unaltered with the present fatiguing protocol. This study assessed the effects of a competitive trail run on running kinematics and shock attenuation in well-trained trail runners. Nine male runners performed a simulated short trail running race. Prior and 5-min after the race, participants completed a 290-m downhill run at pre-determined preferred speed. Inertial measurement units were used to assessselected kinematic parameters. The contact time showed a moderate increase in the fatigued condition (pre: 0.215 (0.024) s vs. post: 0.226 (0.219) s; p2vs. post: 49.1 (11.9) m/s2; p=0.038; d=0.56), while peak tibial acceleration and shock attenuation showed no change (p\u3e0.05). These findings confirm that running-induced fatigue impacts running kinematics, although shock attenuation was unaltered with the present fatiguing protocol

    CENTRE OF MASS TRAJECTORY IN SNOWBOARD GIANT SLALOM USING INERTIAL SENSORS: LABORATORY AND IN-FIELD PRELIMINARY EVALUATION

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    The purpose of the present study was to evaluate the reconstruction accuracy of the centre of mass during snowboard giant slalom using inertial sensors (Opal, APDM, 128 Hz). Two approaches were implemented and tested: i) a multi-segment model using 7 inertial sensors on the trunk, the pelvis, the thighs, the shanks, and the board; and ii) a double integration of the acceleration at L5 level measured with one inertial sensor. The accuracy of the algorithms was verified in two laboratory conditions: a) the multi-segment model approach was tested indoor during controlled movements using stereo-photogrammetry as gold standard, and b) the double integration of acceleration approach was tested outdoor in simulated movements on a longboard using GPS as gold standard. Successively, to verify the application in real conditions, an in-field acquisition of a forerunner athlete during a snowboard world cup competition was performed. The position of the centre of mass estimated indoor with multi-segmental model approach reported in the local reference frame of the board showed high correlation with respect to stereo-photogrammetry (r=0.87) and a RMS error of 3.8 [%] expressed as percentage of the range of motion during the trial (1.32m). For the simulated movements test in outdoor conditions on the longboard applying the double integration approach, high correlation was found with respect to the GPS data (r=0.95) on the trajectory but , for the 4 turns trial, a RMS difference on the distance equal to 15.3 [%] expressed as percentage of the whole distance covered (46m). Finally, the in-field acquisition showed how using inertial sensors is a viable option for collecting centre of mass data during training session useful for coaches and athletes. The approach using one sensors at L5 level showed low level of accuracy with respect to the one using a multi-segment model. Further developments should be performed in the direction of a better estimation of the orientation of the inertial sensors and of the boundary conditions for the integration algorithm

    Effects of Aflatoxin B1 and Fumonisin B1 on the Viability and Induction of Apoptosis in Rat Primary Hepatocytes

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    The present study evaluated the effect of aflatoxin B1 (AFB1) and fumonisin B1 (FB1) either alone, or in association, on rat primary hepatocyte cultures. Cell viability was assessed by flow cytometry after propidium iodine intercalation. DNA fragmentation and apoptosis were assessed by agarose gel electrophoresis and acridine orange and ethidium bromide staining. At the concentrations of AFB1 and FB1 used, the toxins did not decrease cell viability, but did induce apoptosis in a concentration and time-dependent manner

    Lezione vela

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    Prof. Semprini GPS tools

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    SPORT INDIVIDUALI

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    CLASSIFICAZIONE DEGLI SPORT

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