88,401 research outputs found

    Bacteriostatic conformal coating for electronic components

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    Coating for electronic components used in space applications has bacteriostatic qualities capable of hindering bacterial reproduction, both vegetative and sporulative viable microorganisms. It exhibits high electrical resistivity, a low outgassing rate, and is capable of restraining electronic components when subjected to mechanical vibrations

    Bacteriostatic conformal coating and methods of application Patent

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    Development of bacteriostatic conformal coating and methods of applicatio

    Conformational Control of Exciton-Polariton Physics in Metal - Poly(9,9-dioctylfluorene) - Metal Cavities

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    Control is exerted over the exciton-polariton physics in metal - Poly(9,9-dioctyl fluorene) - metal microcavities via conformational changes to the polymer backbone. Using thin-film samples containing increasing fractions of β\beta-phase chain segments, a systematic study is reported for the mode characteristics and resulting light emission properties of cavities containing two distinct exciton sub-populations within the same semiconductor. Ultrastrong coupling for disordered glassy-phase excitons is observed from angle-resolved reflectivity measurements, with Rabi splitting energies in excess of 1.05 eV (more than 30% of the exciton transition energy) for both TE- and TM-polarized light. A splitting of the lower polariton branch is then induced via introduction of β\beta-phase excitons and increases with their growing fraction. In all cases, the photoluminescence emanates from the lowermost polariton branch, allowing conformational control to be exerted over the emission energy and its angular variation. Dispersion-free cavities with highly saturated blue-violet emission are thus enabled. Experimental results are discussed in terms of the full Hopfield Hamiltonian generalized to the case of two exciton oscillators. The importance of taking account of the molecular characteristics of the semiconductor for an accurate description of its strong coupling behaviour is directly considered, in specific relation to the role of the vibronic structure

    Match injuries in professional soccer: inter-seasonal variation and effects of competition type, match congestion and positional role

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    In this prospective observational study, injuries sustained in official match-play in players belonging to a professional soccer club were investigated. Incidence and patterns of injury were compared across four-seasons (2005-2006: S1, 2006-2007: S2, 2007-2008: S3 and 2008-2009: S4) and 3 match formats (domestic League/Cup games and European club competition). In addition, the effects of both fixture congestion and the positional role of players were investigated. Injury incidence (per 1 000 match-hours) did not vary between seasons (range 31.2-59.2 observed in S2 and S4, respectively, p=0.12) or fixture formats (range 32.6-40.8 observed in European and League matches, respectively, p=0.49). In contrast, rates varied in players (n=7) who participated in all four seasons as more injuries were sustained in S1 compared to S2 and S3, respectively (88.4 vs. 49.0 vs. 49.2, both p or = 4 days). Finally, the incidence of injury and muscle strains (both p<0.001) varied across positional roles with the highest rates observed in centre-forwards. These findings provide further knowledge on the risk of injury in contemporary professional soccer match-play and may aid in the care and management of playing resources

    Effects of physical efforts on injury in elite soccer

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    In this study, the influence of physical efforts on occurrence of match injury in a professional soccer club was investigated. Computerised motion-analysis was used to measure the physical efforts of players during 10 injury situations. Total distance and those covered at different movement intensities were measured across the 5-min period preceding injury. If the final run preceding injury involved a high-intensity action (HIA), the distance, duration and speed of the effort and the recovery time between this and the penultimate HIA were measured. To determine the influence of these physical efforts, the results were compared to a normative profile for players computed from data across 5 games for the same variables; habitual distances covered over a 5-min period and characteristics of and recovery time between HIA. Compared to the normative profile, no differences were reported in physical characteristics during the period leading up to injury or for HIA although the latter were substantially higher in intensity (duration and distance). A lower than normal recovery time between HIA prior to injury was observed (35.6±16.8 s vs. 98.8±17.5 s, p=0.003). Within the limitations of the small sample, these findings may aid in further understanding injury and physical performance in elite soccer

    Body size, skeletal maturity and functional characteristics of elite academy soccer players on entry between 1992 and 2003

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    Secular changes in body size, estimated fatness, skeletal maturation, and functional characteristics of youth soccer players on entry into an elite academy between 1992 and 2003 were compared. Annual selections grouped across time (1992–1995, 1996–1998, 1999–2003), playing position (goalkeeper, defender, midfielder, forward), and by eventual status in the sport (professional, non-professional) were compared. Data for 158 players (age 13.4 ± 0.4 years) at entry into the academy included skeletal age (Greulich-Pyle method), height, weight, relative fatness, four field tests of functional capacities (aerobic, anaerobic, power, speed), and quadriceps concentric strength of the dominant and non-dominant legs. MANCOVA with age as the covariate and chi square were used for comparisons across years. With few exceptions (but notably estimated [Vdot]O2max), results for player size, functional characteristics, and skeletal maturation did not differ among years. Distributions of players by skeletal maturity status and within each playing position also did not differ between years. Although related research has suggested that the anthropometric characteristics of professional players and demands of contemporary professional soccer competition increased over this period, the size, maturity, and functional characteristics of youth players on entry to an elite academy and of graduates who eventually played soccer as professionals generally did not change across annual selections from 1992 to 2003. The results suggest a lack of change in selection philosophies and practices of coaches involved in recruiting players for the academy, which in turn is reflected in consistency of specific evaluation criteria employed over the decade considered

    Are physical performance and injury risk in a professional soccer team in match-play affected over a prolonged period of fixture congestion?

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    In this study, the effects of a prolonged period of fixture congestion (8 successive official matches in 26-days) on physical performance and injury risk and severity in a professional soccer team were investigated. Computerised motion-analysis was used to analyse the overall distance covered and that run at light- (0.0-11.0 km•h-1); low- (11.1-14.0 km•h-1); moderate- (14.1-19.7 km•h-1) and high-intensities (≥19.8 km•h-1) for the team as a whole. Distances were measured in metres per minute. Information on match injuries was recorded prospectively. The overall distance covered varied across successive matches (p<0.001) as more distance was run in games 4 and 7 compared to 2 and 3 respectively (126.6±12.3 m•min-1 and 125.0±13.2 m•min-1 vs. 116.0±8.0 m•min-1 and 115.5±11.0 m•min-1). Distance run in light-intensity exercise also varied (p<0.001) as more distance was covered in game 4 versus 1, 2, 3, 5 and 6 (75.5±3.8 m•min-1 vs. 70.6±2.4 m•min-1, 71.8±3.4 m•min-1, 69.3±2.6 m•min-1, 71.5±3.1 m•min-1, and 70.3±2.8 m•min-1) and in game 8 versus game 3 (73.1±3.8 vs. 69.3±2.6 m•min-1) respectively. When comparing match halves, there were no differences across games in overall or high-intensity distance covered and performance in these measures was similar for matches played before, during and after this period. Globally, no difference over the 8 games combined was observed between the reference team and opponents in any of the performance measures whereas the overall distance covered and that in low- (both p<0.001) and high-intensity running (p=0.040) differed in individual games. The incidence of match injury during the congested fixture period was similar to rates reported outside this period but the mean layoff duration of injuries was substantially shorter during the former (p<0.05). In summary, while the overall distance run and that covered at lower intensities varied across games, high-intensity running performance and injury risk were generally unaffected during a prolonged period of fixture congestion. These results might be linked to squad rotation and post-match recovery strategies in place at the present club

    Experimental Study of Diamond Like Carbon (DLC) Coated Electrodes for Pulsed High Gradient Electron Gun

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    For the SwissFEL Free Electron Laser project at the Paul Scherrer Institute, a pulsed High Gradient (HG) electron gun was used to study low emittance electron sources. Different metals and surface treatments for the cathode and anode were studied for their HG suitability. Diamond Like Carbon (DLC) coatings are found to perform exceptionally well for vacuum gap insulation. A set of DLC coated electrodes with different coating parameters were tested for both vacuum breakdown and photo electron emission. Surface electric fields over 250MV/m (350 - 400kV, pulsed) were achieved without breakdown. From the same surface, it was possible to photo-emit an electron beam at gradients up to 150MV/m. The test setup and the experimental results are presentedComment: 4 pages, 14 figures, IPMHVC 2010 : IEEE International Power Modulator and High Voltage Conferenc
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