Aim of the study: to identify mutual interaction between the reaction to a moving object with functional state of the central nervous system and kinematic-dynamic parameters of complex coordination movement.Materials and methods: 9 elite alpine skiers were participated in this study. Visual-motor coordination variables were assessed by computer complex for psychophysiological testing NS-Psychotest (Neurosoft, Russia). Dynamic parameters of complex coordination movement during counter movement jump were registered on the MuscleLab Force Plate (Ergotest Innovation A.S., Norway). Quantitation of hormones — adrenaline and noradrenaline as well as neurotransmitters — dopamine and serotonin in blood samples was performed using ultra-high performance liquid chromatograph combined with triple quadrupole mass analyzer LCMS-8060 (Shimadzu, Japan).Results: a significant negative relationship between the maximum output of motor efforts during counter movement jump, mean reaction time and the number of negative reactions recorded within visual-motor coordination testing was documented. A reliable positive relationship between excitation processes, jump power and jump time was established. Increases in noradrenaline and serotonin concentrations are positively associated with the number of accurate reactions, whereas dopamine level was positively correlated with jump altitude.Conclusion: the predominance of excitation over inhibition processes in the central nervous system had a positive effect on reducing the time spent on counter moving and increasing the maximum power of movement. As applied to alpine skiers we registered the following relationship: the higher the speeds of signal perception and muscle activation when solving a visual-motor task, the higher the power of working efforts, the shorter the time of the eccentric phase and total time spent on performing counter movement jump.
In [1976][1977], at the Donetsk branch of NIGRI, plans were drawn up for the ER-315/630 bucket-wheel excavator with increased digging force, intended for working compact clays and kaolins in sites of the Ministry of F e r r o u s Metallurgy [Minchermet] of the USSR. The first e~perimental specimen was built in the electromechanical workshops of the Mining Administration of the Semiluki R e f r a c t o r i e s Works. Use was made of the experience gained in building and using small bucket-wheel excavators at the Chasov-Yar, Vladimirovka, and other deposits of r e f r a c t o r i e s raw m a t e r i a l s in the Ukraine, and also at q u a r r i e s attached to the Semiluki works.The machine is a swiveling tracked bucket-wheel excavator ( Fig. 1), cutting laterally, with a stationary balanced rotor arm, an unbalanced discharge a r m of the cantilever type, and a rotating platform carrying the equipment, gantry, control cabin, and electrical gear and also a counterweight for the rotor arm. The a r m s are hung from cables; this simplifies servicing and improves the reliability in winter. The a r m s are swiveled and raised by independent drives. The machine is controlled from a cabin containing a control panel. The discharge a r m can be controlled remotely. The drives for the main and auxiliary m e c h a n i s m s are fitted with ac motors.The working parts of the excavator include a r o t o r arm, a take-up conveyer, and the cutting head with a drive consisting of an electric motor, a clutch, and a reducing gear.The metal body of the rotor a r m is a box g i r d e r with constant width and varying depth. The fork carrying the rotor a r m and the pivot where the a r m is attached to the gantry are also box-shaped. The conveyer is mounted on the arm.The cutting head of the excavator is a bucket-wheel of the nonchambered type with unilateral gravitational discharge. The rotor wheel is fitted with ten buckets. The bottom of the bucket can be of the chain or continuous type.The shaft mounting of the rotor wheel (Fig. 2) includes the wheel 1, hub 2 with a cylindrical well and a conical surface, shaft 3 with two conical bearing surfaces, split bush 4, p r e s s u r e plate 5, draw-in bolts Fig. 1. The ER-315/630 bucket-wheel excavator at the face.Soyuzogneupor, DonNIGRI. Semiluki R e f r a c t o r i e s Works.
With the aim of improving the reliability and ease of maintenance of the ERG-120 excavator, at DonNIGRI we have modified its facilities [i] --the drives to the caterpillar tracks, conveyers, and dependent and independent slewing of the dumping arm, the gantry, and the cabin.In the modification of the drive to the caterpillar tracks, the RM'650 reducing gear and the open transmission, which did not have rigidly centered gearing, were united in a three-stage reducing gear 1 (Fig. 1) with an overall transmission ratio of i = 100.9. The welded casing of the reducing gear was made the same for the right-hand and left-hand drives. Output shaft--pinion 2, meshing with gear wheel 3, is fixed in bearings 4 and serves as the main support of the gear mechanism. An additional support is provided by pivot 5, welded to the casing on the same side as the output shaft, and fixed to bracket 6 of the rear beam. To the same bracket is fixed electric motor 7. Shaft and pinion 2 and gear wheel 3 are made single instead of double, with an increased module m = 22. The boring of holes in the drive casing for shaft and pinion 2 and driving half-axle 8 from one setting gives adequate centering of the final drive. The principal kinematic characteristics of the caterpillar track drive are listed in Table 1.Instead of a one-stage reducing gear and an open-toothed transmission with internal gearing, the rim of which is made integral with the drum, the conveyer drives have a two-stage reducing gear. The drive of the dumping conveyer is fitted with an output pinion on the shaft of the drum; in the drive to the feed conveyer the output shaft is connected to the drum shaft by means of a flanged coupling. The dram is in turn fixed to a shaft which bears on the roller bearing. The reducing gear of the damping conveyer is connected to the electric motor by a uni~rsal-joint shaft, and the reducing gear of the feed conveyer is connected by an elastic coupling.Deviation of the discharge end of the dumping conveyer from its longitudinal axis as a result of eccentricity of the axes of rotation of the dumping and rotor arms is governed by the transmission ratio of the drive for dependent rotation of the dumping arm. With the aim of reducing the deviation in the last open transmission of the drive, the number of teeth of the gears and correspondingly the intercenter distance are altered. The rate of independent rotation of the damping arm is increased by using an AO2-42-4 motor with a rotation frequency of 1440 rpm.The gantry was reconstructed with the aim of increasing its rigidity and strength. The general design of the gantry --a three-dimensional tetrahedral truss narrower at the top --was not altered; but the struts
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