Search results for "motor"
showing 10 items of 3137 documents
Design criteria of tubular linear induction motors and generators: A prototype realization and its characterization
2013
In this paper a mathematical model of tubular linear induction machines (TLIM) with hollowed induced part is recalled. Moreover the design criteria of a TLIM with hollowed iron induced part are presented as well as the technological processes to be adopted and the choice of materials to construct the various parts. The methodologies for mechanical assembling and electric wiring are considered too. A prototype with bimetallic induced part has been designed and built. Finally some experimental results on electrical and mechanical variables, when the machines are used as motors, are shown.
Identification and Experimental Validation of an Induction Motor Thermal Model for Improved Drivetrain Design
2017
The ability of an electric powertrain to perform according to mechanical specifications is equally important as assessing its thermal protection limits, which are affected by its electrical and thermal properties. Although rated parameters (such as power, torque, etc.) are easily accessible in catalogs of equipment producers, more specific properties like mass/length of copper winding, heat dissipation factor, etc., are not available to customers. Therefore, an effective selection of drivetrain components is limited due to the lack of sufficient data and the need to consult critical design decisions with suppliers. To overcome this limitation, we propose a method to estimate the temperature…
Modifying the texture of foods for infants and young children
2015
The first section of this chapter describes the evolutions in oral physiology (anatomical motor components, oral motor skills and feeding skills) in healthy children (< 3 years). The second section describes how each type of texture is accepted at each oral physiology stage, and how exposures to textures impact oral physiology development and acceptability of textures. The third section shows how the need to modify food texture for infant foods is addressed, through national regulations or recommendations from public health bodies, and describes practices of texture modification, based on national surveys and case reports (including baby-led weaning). The chapter is closed by a commentary o…
Electrophysiological correlates of the cognitive control processes underpinning mixing and switching costs
2016
Typically, in task-switching contexts individuals are slower and less accurate when repeating a task in mixed blocks compared to single-task blocks (mixing cost) and when switching to a new task compared to repeating a previous one (switch cost). Previous research has shown that distinct electrophysiological correlates underlie these two phenomena. However, this evidence is not a consistent result. The goal of this study was to better characterize differences between the control processes involved in mixing and switch costs. To this aim, we examined event-related potentials (ERPs) evoked during a cued task-switching experiment. In order to minimize the confounding effects of cognitive deman…
The Cumulative Effect of Transient Synchrony States on Motor Performance in Parkinson's Disease.
2020
Bursts of beta frequency band activity in the basal ganglia of patients with Parkinson's disease (PD) are associated with impaired motor performance. Here we test in human adults whether small variations in the timing of movement relative to beta bursts have a critical effect on movement velocity and whether the cumulative effects of multiple beta bursts, both locally and across networks, matter.
The effect of alertness and attention on the modulation of the beta rhythm to tactile stimulation
2021
Abstract Beta rhythm modulation has been used as a biomarker to reflect the functional state of the sensorimotor cortex in both healthy subjects and patients. Here, the effect of reduced alertness and active attention to the stimulus on beta rhythm modulation was investigated. Beta rhythm modulation to tactile stimulation of the index finger was recorded simultaneously with MEG and EEG in 23 healthy subjects (mean 23, range 19–35 years). The temporal spectral evolution method was used to obtain the peak amplitudes of beta suppression and rebound in three different conditions (neutral, snooze, and attention). Neither snooze nor attention to the stimulus affected significantly the strength of…
Evidence of a preprogrammed deactivation of the hamstring muscles for triggering rapid changes of posture in humans
1997
Normal subjects were asked to make rapid flexions of the legs from a stationary initial standing posture in a self-paced mode. Because this movement implicates a rapid change in posture, questions were asked about the type of central command which must include the rupture of the erect posture and the accomplishment of the goal directed movement. Movements of the different segments of the body were recorded and analyzed using the optoelectronic ELITE system. Electromyographic (EMG) activities of 8 muscles of the lower limb on one side were recorded, rectified and integrated. The time relationships of the different EMG signals (activation or deactivation) were analyzed with respect to selecte…
Long-term leisure time physical activity and properties of bone: A twin study
2009
Effects of physical activity on bone properties, when controlled for genetic effects, are not fully understood. We aimed to study the association between long-term leisure time physical activity (LTPA) and bone properties using twin pairs known to be discordant for leisure time physical activity for at least 30 yr. Volumetric BMD and geometric properties were measured at the tibia shaft and distal end using pQCT in 16 middle-aged (50-74 yr) same-sex twin pairs (seven monozygotic [MZ] and nine dizygotic [DZ] pairs) selected from a population-based cohort. Paired differences between active and inactive co-twins were studied. Active members of MZ twin pairs had larger cortical bone cross-secti…
Association of lifestyle habits and academic achievement in Norwegian adolescents: a cross-sectional study
2014
Published version of an article in the journal: BMC Public Health. Also avialable from the publisher: http://dx.doi.org/10.1186/1471-2458-14-829 Background: While healthy lifestyle habits are generally assumed to be important for high academic achievement, there has been little research on this topic among adolescents. The aim of this study was therefore to examine the associations between several lifestyle habits and academic achievement in adolescent girls and boys. Methods: The study included 2,432 Norwegian adolescents, 15–17 years old. A self-report questionnaire was used to assess dietary-, physical activity-, smoking- and snuffing habits and academic achievement. Logistic regression …
The Psychology of Fluent Use
2016
In a perfect world, it would always be possible to operate technology effortlessly and to reach the desired goal. However, in the real world many factors may make technologies difficult to use or even hinder people from using technical artefacts. Most of these factors pertain to usability (i.e., technology’s ability to fit users’ capabilities) and thus concern technological solutions from the point of view of human beings as users of technology. Therefore, designing technical artefacts that are easy to use requires understanding the psychological and mental preconditions for using technology.