Alternating current (ac) and direct current (dc) conductivities have been measured in polymer-nanotube composite thin films. This was carried out for a range of concentrations of multiwall nanotubes in two polymer hosts, poly(m-phenylenevinylene-co-2,5-dioctyloxyp-phenylenevinylene) (PmPV) and polyvinylalcohol (PVA). In all cases the dc conductivity σDC was ohmic in the voltage range studied. In general the ac conductivity displayed two distinct regions, a frequency independent region of magnitude σ0 at low frequency and a frequency dependent region at higher frequency. Both σDC and σ0 followed a percolation scaling law of the form σ∝(p−pc)t with pc=0.055% by mass and t=1.36. This extrapolates to a conductivity of 1×10−3 S/m for 100% nanotube content. Such a low value reflects the presence of a thick polymer coating, resulting in poor electrical connection between tubes. This leads to the suggestion that charge transport is controlled by fluctuation induced tunneling. In the high frequency regime the cond...
A modified shoving model is applied to estimate the location of the glass transition in a one-component plasma. The estimated value of the coupling parameter $Γ\simeq 570$ at the glass transition is compared with other predictions available in the literature.
H. Kobori, Elizabeth R. Ellwood, A. Miller‐Rushing
et al.
Beyond Nept une' s orbit lies a vast swat h of space called t he Kuiper Belt , cont aini ng more t han 100,000 large obj ects t hat have remained relatively unchanged i n space for more than 4.5 billion years. Understanding t hese objects coul d shed l ight on t he cond itions that gave birth t o our solar system and w it h t he help of a Cal Poly professo r, t he next d iscovery i n this field of knowledge cou ld be made by a high school student in a tiny cal ifornia mountai n t own.
In this analysis an application of integrated fuzzy soft set theory and Hungarian method in MCDM problem is used to evaluate the ranking order of players and their position in the game. The problem’s objective is to select an each player’s suitable position out of seven positions namely Goal Shooter, Goal Attack, Wing Attack, Centre, Wing Defence, Goal Defence, and Goal Keeper. From the comprehensive decision matrix, Hungarian method is applied to assign a suitable position to each player.
F. García-Pinillos, J. A. Laredo-Aguilera, Marcos Muñoz-Jiménez
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Abstract García-Pinillos, F, Laredo-Aguilera, JA, Muñoz-Jiménez, M, and Latorre-Román, PA. Effects of 12-week concurrent high-intensity interval strength and endurance training program on physical performance in healthy older people. J Strength Cond Res 33(5): 1445–1452, 2019—This study aimed to analyze the effect of 12-week low-volume high-intensity interval training (HIIT)-based concurrent training program on body composition, upper- and lower-body muscle strength, mobility, and balance in older adults, as well as to compare it with a low-moderate–intensity continuous training. Ninety active older adults were randomly assigned to experimental group (EG, n = 47) and control group (CG, n = 43). Body composition and physical functioning were assessed before (pretest) and after (posttest) a 12-week intervention. A 2-way repeated measures analysis of variance was used to test for an interaction between training program and groups. The time × group interaction revealed no significant between-group differences at pretest (p ≥ 0.05). The group × time interaction showed significant improvements for the EG in body composition parameters (p ⩽ 0.05) and physical functioning (muscle strength: p < 0.001; mobility: p < 0.001; and balance: p ⩽ 0.05); whereas the CG remained unchanged (p ≥ 0.05). This HIIT-based concurrent training program led to greater improvements in body composition, muscle strength, mobility, and balance in healthy older people than a regular low-moderate–intensity continuous training, despite the reduction in overall training volume.
Abstract Darrall-Jones, JD, Jones, B, and Till, K. Anthropometric and physical profiles of English academy rugby union players. J Strength Cond Res 29(8): 2086–2096, 2015—The purpose of this study was to evaluate the anthropometric and physical characteristics of English regional academy rugby union players by age category (under 16s, under 18s and under 21s). Data were collected on 67 academy players at the beginning of the preseason period and comprised anthropometric (height, body mass, and sum of 8 skinfolds) and physical (5-, 10-, 20-, and 40-m sprint, acceleration, velocity, and momentum; agility 505; vertical jump; Yo-Yo intermittent recovery test level 1; 30-15 intermittent fitness test; absolute and relative 3 repetition maximum front squat, split squat, bench press, prone row, and chin; and isometric mid-thigh pull). One-way analysis of variance demonstrated significant increases across the 3 age categories (p ⩽ 0.05) for height (e.g., 16s = 178.8 ± 7.1; 18s = 183.5 ± 7.2; 21s = 186.7 ± 6.61 cm), body mass (e.g., 16s = 79.4 ± 12.8; 18s = 88.3 ± 11.9; 21s = 98.3 ± 10.4 kg), countermovement jump height and peak power, sprint momentum, velocity, and acceleration; absolute, relative, and isometric (e.g., 16s = 2,157.9 ± 309.9; 18s = 2,561.3 ± 339.4; 21s = 3,104.5 ± 354.0 N) strength. Momentum, maximal speed, and the ability to maintain acceleration were all discriminating factors between age categories, suggesting that these variables may be more important to monitor rather than sprint times. These findings highlight that anthropometric and physical characteristics develop across age categories and provide comparative data for English Academy Rugby Union players.
Using high-contrast imaging with the SPHERE instrument at the Very Large Telescope (VLT), we report the first images of a cold brown dwarf companion to the exoplanet host star HD 4113A. The brown dwarf HD 4113C is part of a complex dynamical system consisting of a giant planet, a stellar host, and a known wide M-dwarf companion. Its separation of 535 ± 3 mas and H-band contrast of 13.35 ± 0.10 mag correspond to a projected separation of 22 AU and an isochronal mass estimate of 36 ± 5 MJ based on COND models. The companion shows strong methane absorption, and through fitting an atmosphere model, we estimate a surface gravity of logg = 5 and an effective temperature of ~500–600 K. A comparison of its spectrum with observed T dwarfs indicates a late-T spectral type, with a T9 object providing the best match. By combining the observed astrometry from the imaging data with 27 years of radial velocities, we use orbital fitting to constrain its orbital and physical parameters, as well as update those of the planet HD 4113A b, discovered by previous radial velocity measurements. The data suggest a dynamical mass of 66−4+5 MJ and moderate eccentricity of 0.44−0.07+0.08 for the brown dwarf. This mass estimate appears to contradict the isochronal estimate and that of objects with similar temperatures, which may be caused by the newly detected object being an unresolved binary brown dwarf system or the presence of an additional object in the system. Through dynamical simulations, we show that the planet may undergo strong Lidov-Kozai cycles, raising the possibility that it formed on a quasi-circular orbit and gained its currently observed high eccentricity (e ~ 0.9) through interactions with the brown dwarf. Follow-up observations combining radial velocities, direct imaging, and Gaia astrometry will be crucial to precisely constrain the dynamical mass of the brown dwarf and allow for an in-depth comparison with evolutionary and atmosphere models.