We tested a hypothesis that low-load squat training with slow movement and tonic force generation (LST) would increase muscle size and strength but not necessarily power. Healthy young men were ...assigned to LST 50% one-repetition maximum (1-RM) load, 3 s for lowering/lifting without pause: n=9 or low-load normal speed (LN: 50% 1-RM load, 1 s for lowering/lifting with 1-s pause; n=7) groups. Both groups underwent an 8-week squat training program (10 repetitions/set, 3 sets/day, and 3 days/week) using the assigned methods. Before and after the intervention, quadriceps femoris muscle thickness, maximal torque during isometric hip extension and knee extension, 1-RM squat, lifting power from squatting position and rate of electromyography rise (RER) in knee extensors during the task, leg extension power and vertical jump height were measured. After the intervention, the LN group showed no changes in all the variables. The LST group significantly (P<0.05) increased muscle thickness (6-10%), isometric hip extension torque (18%) and 1-RM squat (10%), but not isometric knee extension torque, lifting power and RER, leg extension power and vertical jump height. These results suggest that LST can increase muscle size and task-related strength, but has little effect on power production during dynamic explosive movements.
Arbitrary discontinuities in finite elements Belytschko, T.; Moës, N.; Usui, S. ...
International journal for numerical methods in engineering,
10 February 2001, Volume:
50, Issue:
4
Journal Article
The force of interaction between two flat double layers with dissimilar surface potentials but of the same signs, in contact with 1–1 electrolyte solutions (0.001, 0.01, and 0.1 M), was calculated as ...a function of the surface separation. The calculation was carried out on the basis of the Gouy–Chapman–Stern–Grahame double-layer model, incorporating the site-dissociation and site-binding model used previously for many oxide studies. The results demonstrated that the interaction force under surface charge regulation was always repulsive, increasing progressively with decreasing surface separation. This result is in contrast to the predictions of previous theories that are based on the Gouy–Chapman (GC) double-layer model. Dependence of surface potentials and surface charge densities on the surface separation is also presented.
On the NMR dose sensitivities of polyacrylamide-based gel dosimeters irradiated by X-ray, the additive effect of various inorganic salts (electrolytes) is investigated. Among the various combination ...of cations (Li+, Na+, K+, Mg2+, Ca2+, Sr2+, Ba2+, Zn2+ and Al3+) and anions (Cl−, NO−3 and SO2-4), MgCl2 is shown to be the most effective sensitizer. In the result, it is suggested that the extent of the increase of the dose sensitivity may correlate to the hydration power of cations rather than anions. Contrary to the dose sensitivity enhancement, the depression of melting point caused by the additives is also pointed out.
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