322 research outputs found

    Characterization of a nondestructive beam profile monitor using luminescent emission

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    The LHC (large hadron collider) [LHC study group: LHC. The large hadron collider conceptual design; CERN/AC/95-05] is the future p-p collider under construction at CERN, Geneva. Over a circumference of 26.7 km a set of cryogenic dipoles and rf cavities will store and accelerate proton and ion beams up to energies of the order of 7 TeV. Injection in LHC will be performed by the CERN complex of accelerators, starting from the source and passing through the linac, the four booster rings, the proton synchrotron (PS), and super proton synchrotron (SPS) accelerators. One of the main constraints on LHC performance is emittance preservation along the whole chain of CERN accelerators. The accepted relative normalized emittance blowup after filamentation is ±7%. To monitor the beam and the emittance blowup process, a study of different prototypes of nonintercepting beam profile monitors has been performed. In this context a monitor using the luminescent emission of gases excited by ultrarelativistic protons (450 GeV) was developed and tested in the SPS ring. The results of beam size measurements and their evolution as a function of the machine parameters are presented. The image quality and resolution attainable in the LHC case have been assessed. A first full characterization of the luminescence cross section, spectrum, decay time, and afterglow effect for an ultrarelativistic proton beam is provided. Some significant results are also provided for lead ion beams

    LHC Beam Loss Monitors

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    At the Large Hadron Collider (LHC) a beam loss system will be installed for a continuous surveillance of particle losses. These beam particles deposit their energy in the super-conducting coils leading to temperature increase, possible magnet quenches and damages. Detailed simulations have shown that a set of six detectors outside the cryostats of the quadrupole magnets in the regular arc cells are needed to completely diagnose the expected beam losses and hence protect the magnets. To characterize the quench levels different loss rates are identified. In order to cover all possible quench scenarios the dynamic range of the beam loss monitors has to be matched to the simulated loss rates. For that purpose different detector systems (PIN-diodes and ionization chambers) are compared

    L’intelligenza artificiale nei servizi sociali e sanitari: una nuova sfida al ruolo delle istituzioni pubbliche nel welfare italiano?

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    The paper illustrates the applications of digital and artificial intelligence technologies in social and health services and emphasizes the need of careful regulation by public authorities to ensure equality and constitutional rights

    Brevi note sulla declinazione della sussidiarietĂ  verticale nelle esperienze federo-regionali europee con uno sguardo alla pandemia

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    The study illustrates the development of the idea of subsidiarity and its recognition as a legal and constitutional principle in the sources of European states. Then analyzes the impact of the COVID-19 pandemic on the application of the principle in relations between levels of government in Germany, Swiss and Italy. In this crisis, the principle of subsidiarity can play an important role in enhancing the demands of the lowest levels of government, if accompanied by a robust and consolidated cooperative system between the center-periphery, while where the paths of collaboration and cooperation between the levels of government are weakening the principle of subsidiarity lends itself to a reading more favorable to centripetal dynamics

    Seasonal changes in physical capacities of basketball players according to competitive levels and individual responses

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    PURPOSE:The aim of this study was to quantify changes in physical capacities of thirty-eight basketball players selected from different teams, as well as from varying competitive levels (i.e. Division I, Division II and Division III) during the preparation and in-season periods. METHODS:Pre (T1) and post (T2) preparation period and during regular season (T3), the players completed a Yo-Yo Intermittent Recovery test-level 1. Following a 3 to 8 days-break, players performed a 6-min continuous running test (Mognoni's test), a counter-movement jump test and a 5-min high-intensity intermittent running test. RESULTS:Blood lactate concentration measured after the Mognoni's test was significantly reduced from T1 to T2, and from T2 to T3 (P<0.001, Ćž2 = 0.424). The distance covered during the Yo-Yo Intermittent Recovery test was significantly increased only from T1 to T2 in Division II and III (P<0.001, Ćž2 = 0.789). Similarly, the physiological responses to high-intensity intermittent running test were improved only from T1 to T2 (all P<0.001, Ćž2 = 0.495 to 0.652). Despite significant changes observed in running tests from T1 to T2, at individual level 35-55% of players did not show a very likely improvement. Relative peak power produced during vertical jumps at T3 by Division I players was increased compared to T1 (ANOVA interaction, P = 0.037, Ćž2 = 0.134). CONCLUSIONS:The main improvements in physical capacities occurred during the preparation period, when the aerobic fitness and the ability to sustain high-intensity intermittent efforts were moderately-to-largely improved. However, it appears that the preparation period does not consistently impact on vertical jump variables. Aerobic fitness and force/power production during vertical jumps appear to improve across the competitive season (slightly-to-moderately). Physical tests should be used to identify weaknesses in physical performance of players and to monitor their fatigue status, with the aim to develop individualized training programs

    Crossing Over from Attractive to Repulsive Interactions in a Tunneling Bosonic Josephson Junction

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    We explore the interplay between tunneling and interatomic interactions in the dynamics of a bosonic Josephson junction. We tune the scattering length of an atomic 39^{39}K Bose-Einstein condensate confined in a double-well trap to investigate regimes inaccessible to other superconducting or superfluid systems. In the limit of small-amplitude oscillations, we study the transition from Rabi to plasma oscillations by crossing over from attractive to repulsive interatomic interactions. We observe a critical slowing down in the oscillation frequency by increasing the strength of an attractive interaction up to the point of a quantum phase transition. With sufficiently large initial oscillation amplitude and repulsive interactions the system enters the macroscopic quantum self-trapping regime, where we observe coherent undamped oscillations with a self-sustained average imbalance of the relative well population. The exquisite agreement between theory and experiments enables the observation of a broad range of many body coherent dynamical regimes driven by tunable tunneling energy, interactions and external forces, with applications spanning from atomtronics to quantum metrology.Comment: 10 pages, 8 figures, supplemental materials are include

    The preparation period in basketball: Training load and neuromuscular adaptations

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    © 2018 Human Kinetics, Inc. Purpose: To investigate the effect of the preparation period on neuromuscular characteristics of 12 professional (PRO) and 16 semiprofessional (SEMIPRO) basketball players and relationships between training-load indices and changes in neuromuscular physical performance. Methods: Before and after the preparation period, players underwent a countermovement jump (CMJ) test followed by a repeated change-of-direction (COD) test consisting of 4 levels with increasing intensities. The peripheral neuromuscular functions of the knee extensors (peak torque [PT]) were measured using electrical stimulations after each level (PT1, PT2, PT3, and PT4). Furthermore, PT Max (the highest value of PT) and PT Dec (PT decrement from PT Max to PT4) were calculated. Results: Trivial to small (effect size [ES] = -0.17 to 0.46) improvements were found in CMJ variables, regardless of competitive level. After the preparation period, peripheral fatigue induced by a COD test was similarly reduced in both PRO (PT Dec: from 27.8% [21.3%] to 11.4% [13.7%]; ES = -0.71; 90% confidence interval [CI], ±0.30) and SEMIPRO (PT Dec: from 26.1% [21.9%] to 10.2% [8.2%]; ES = -0.69; 90% CI, ±0.32). Moderate to large relationships were found between session rating of perceived exertion training load and changes in peak power output (PPO) measured during the CMJs (rs [90% confidence interval]: PPOabs, -.46 [±.26]; PPOrel, -.53 [±.23]) and in some PTs measured during the COD test (PT1, -.45 [±.26]; PT2, -.44 [±.26]; PT3, -.40 [±.27]; and PT Max, -.38 [±.28]). Conclusions: The preparation period induced minimal changes in the CMJ, while the ability to sustain repeated COD efforts was improved. Reaching high session rating of perceived exertion training loads might partially and negatively affect the ability to produce strength and power

    The Luminescence Profile Monitor of the CERN SPS

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    The SPS luminescence monitor is the first device of this type to be used in a high energy accelerator, from 14 to 450 GeV, where up till now the light production was considered to be insufficient. It uses Nitrogen at pressures as low as 4 10-6 Pa as the scintillation medium. Light production, spectrum and decay times have been measured and compared with theory and existing low energy data. They are important factors for the design of such monitors for other machines, for example LHC

    Results of a phase I-II study on laser therapy for vaginal side effects after radiotherapy for cancer of uterine cervix or endometrium

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    Women who have previously received radiotherapy (RT) for gynecologic cancer often suffer from vaginal fibrosis and stenosis. The success of “non-ablative” laser therapy for postmenopausal vaginal atrophy has led to the idea of testing the laser in patients submitted to RT. In this prospective observational study, we selected patients who underwent pelvic RT followed by vaginal laser treatment. We scheduled three treatment sessions (at T0–T1–T2) and three controls (at T1–T2–T3) one month apart. The follow-up (at T4) was carried out six months after the last treatment. Vaginal Health Index (VHI) and vaginal length were evaluated. Sexual function was assessed through Female Sexual Function Index (FSFI). Overall, 43 patients with severe vaginal shortening, atrophy and stenosis was enrolled and treated with intravaginal non-ablative CO2 laser. We observed a progressive increase in vaginal length of 9% (p = 0.03) at T2 and 28% (p &lt; 0.0001) at T3; effects were maintained at T4 (p &lt; 0.0001). After the first application VHI showed a significant improvement of 57% at T3 (p &lt; 0.0001). The results were maintained at T4 (p &lt; 0.0001). No changes were found in FSFI. All procedures were well tolerated. In conclusion, laser therapy improved vaginal length and VHI in women undergoing pelvic RT; prospective studies are needed

    Peripheral Muscle Function During Repeated Changes of Direction in Basketball

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    PURPOSE: To examine differences between adult male basketball players of different competitive levels (study 1) and changes over a basketball season (study 2) of knee extensor peripheral muscle function during a multi-stage changes of direction exercise (MCODE). METHODS: In study 1, 111 players from 4 different divisions completed the MCODE during the regular season. In study 2, the MCODE was performed before (T1) and after (T2) the preparation period and during the competitive season (T3) by 32 players from division I, II and III. The MCODE comprised 4 levels of increasing intensity for each player. The peak twitch torque (PT) of knee extensors was measured after each level. PTmax (the highest value of PT) and fatigue were calculated. RESULTS: In study 1, we found possibly small differences (ES\ub190%CI: -0.24\ub10.39) in fatigue between division I and II. Division I was characterized by likely (ES: 0.30 to 0.65) and very likely-to-almost certain (ES: 0.74 to 1.41) better PTmax and fatigue levels compared to division III and VI, respectively. In study 2, fatigue was very likely reduced (ES: -0.91 to -0.51) among all divisions from T1 to T2, while PTmax was likely-to-very likely reduced (ES: -0.51 to -0.39) in division II and III. CONCLUSIONS: Professional basketball players are characterized by a better peripheral muscle function during a MCODE. Most of the seasonal changes in peripheral muscle function occurred after the preparation period. These findings inform practitioners on the development of training programs to enhance the ability to sustain repeated changes of direction efforts
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