Search results for " Motor"
showing 10 items of 1044 documents
Visual search in three-dimensional non-medical images: visual-motor performance of radiologists
2019
The visual search abilities of radiologists are systematically trained due to the specifics of their professional tasks. We investigated whether the visual-motor performance of radiologists, residents and students varied when searching non-medical targets on the volumetric display. As a result, no significant differences were found in the correct response rate among three groups. However, the total number of interactions was considerably higher for the resident radiologists and medical students comparing to the experienced radiologists. Our results suggest that the radiological experience does not interfere with the outcome in the developed visual search task, but may be reflected in motor …
Relationship between Wingate test and vertical jump in young female volleyball players
2016
Aims: Maximum vertical jump is an important component in performing spike and block skill in volleyball and is a reflection of explosive muscle strength(Bosco et al. 1983). The Wingate test (WT is used to evaluate anaerobic performance by measuring muscle power during short-term, high-intensity exercise(Bar-Or 1987). The aim of this study was twofold: to investigate the possible relationship between power performance on the Wingate test (WT) and explosive leg strength performed during a vertical counter-movement jump test(CMJ) and whether anaerobic power assessed could identify players with the best performance. Methods: 14 young female volleyball players, age 16–26 years, were grouped by p…
A Hybrid Power Supply with Variable Speed Drive for Automatically Move Irrigation Equipment: Margin of Feasibility
2021
Center pivot irrigation systems are widely used in agriculture. Their water pumping systems are primary energy consumers. The use of photovoltaic power plants and variable speed drives of electric motors can reduce energy costs. The purpose of this study is to determine the feasibility of integrating variable speed drives and photovoltaic modules into water pumping systems. A novel architecture of a pumping system was suggested. Its features are no battery backup and the sale of electricity into the grid.
Performance analysis of photovoltaic powered dc motor — Propeller system
2015
The application of autonomous directly photovoltaic (PV) powered electro-mechanical has received increasing attention for different applications (e.g. PV water pumping, PV powered cooling of arid climate greenhouses, solar vehicles etc). The PV array output is a nonlinear and time-dependent power supply that varies with solar intensity and cell temperature, so the performance characteristics of the directly PV-powered DC motor — propeller system are very different than when powered by a constant DC voltage. The focus of this work is to do performance analysis of directly PV-powered DC motor — propeller system. Through performance evaluation, it has been observed that power transfer matching…
Characterisation of nonoriented electric alloys under nonconventional conditions
1996
The variations of magnetic and loss characteristics of nonoriented cobalt-iron and silicon-iron sheets have been investigated using an Epstein frame. Cobalt-iron alloys have been tested under sinusoidal magnetic flux density with respect to frequency and temperature. Both kinds of alloys have also been investigated with respect to frequency, time constant wavefront and temperature under trapezoidal flux density. The qualitative behaviour is identical under both flux density conditions for all these alloys. These investigations have made it possible to model the variations of iron losses with experimental parameters, except the temperature. These quantitative evolutions differ with alloy and…
Diagnostics of stator winding failures in wind turbine pitch motors using Vold-Kalman filter
2019
Pitch systems are among the most failure-prone components in wind turbines. Winding failures in pitch motors are common due to high start-up loads and poor ventilation. This article presents a diagnostics scheme that can detect the stator winding failures in the pitch motors under time-varying speed and load conditions. The proposed approach based on three-phase motor currents can be directly integrated into the motor drive and can be used for induction as well as permanent magnet synchronous machines. The extended Park's vector calculated on the motor currents is order tracked based on the supply frequency from the drive using Vold-Kalman filter. The approach is shown to be robust under ar…
Characteristics of the polymer transport in ratchet systems
2010
Molecules with complex internal structure in time-dependent periodic potentials are studied by using short Rubinstein-Duke model polymers as an example. We extend our earlier work on transport in stochastically varying potentials to cover also deterministic potential switching mechanisms, energetic efficiency and non-uniform charge distributions. We also use currents in the non-equilibrium steady state to identify the dominating mechanisms that lead to polymer transportation and analyze the evolution of the macroscopic state (e.g., total and head-to-head lengths) of the polymers. Several numerical methods are used to solve the master equations and nonlinear optimization problems. The domina…
Continuous Theta-Burst Stimulation Intensity Dependently Facilitates Motor-Evoked Potentials Following Focal Electrical Stimulation of the Rat Motor …
2020
Although theta-burst stimulation (TBS) is known to differentially modify motor cortical excitability according to stimulus conditions in humans, whether similar effects can be seen in animals, in particular rats, remains to be defined. Given the importance of experimental rat models for humans, this study explored this stimulation paradigm in rats. Specifically, this study aimed to explore corticospinal excitability after TBS in anesthetized animals to confirm its comparability with human results. Both inhibition-facilitation configurations using paired electrical stimulation protocols and the effects of the TBS paradigm on motor-evoked potentials (MEPs) in rat descending motor pathways wer…
Seasonal Changes in physiological parameters in young club level rowers
2013
Aims: To evaluate variations in biometrics, physiological and performance parameters over a seasonal training – from September to March - in club level young rowers. Methods: Six young rowers, age 13-15, affiliated with a rowing club member of the Italian Rowing Federation, were assessed three times at regular three-months intervals (September, December, and March) during the 2011 season. Biometrics evaluations included stature, body mass and body composition, whereas physiological assessments on rowing ergometer included maximum oxygen uptake (VO2max) obtained during an incremental test, and average power output values obtained during a 2000m trial (W2000) and during a 20-sec (W20) and a 6…
Fos mapping of brain activation induced by the mammary pheromone in the newborn rabbit
2010
The female European rabbit, Oryctolagus cuniculus, displays a surprising maternal behaviour. Indeed, she comes into the nest only once per day and for a very brief period (3-4 minutes), almost exclusively to nurse. A pheromonal signal identified as the 2-methylbut-2-enal and named the mammary pheromone (MP) is emitted in milk by all lactating rabbit females. This chemosensory cue induces typical head-searching and oral-seizing movements in newborn rabbits usually involved in the localisation of the nipples. The MP therefore appears as a biological signal important for sucking, survival and growth in pups. To date, only few data are available regarding the neuronal substrate which sustains t…