49 CFR 178.348 - Specification DOT 412; cargo tank motor vehicle.

Science.gov (United States)

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Specification DOT 412; cargo tank motor vehicle... SPECIFICATIONS FOR PACKAGINGS Specifications for Containers for Motor Vehicle Transportation § 178.348 Specification DOT 412; cargo tank motor vehicle. ...

49 CFR 178.347 - Specification DOT 407; cargo tank motor vehicle.

Science.gov (United States)

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Specification DOT 407; cargo tank motor vehicle... SPECIFICATIONS FOR PACKAGINGS Specifications for Containers for Motor Vehicle Transportation § 178.347 Specification DOT 407; cargo tank motor vehicle. ...

49 CFR 178.346 - Specification DOT 406; cargo tank motor vehicle.

Science.gov (United States)

2010-10-01

... 49 Transportation 2 2010-10-01 2010-10-01 false Specification DOT 406; cargo tank motor vehicle... SPECIFICATIONS FOR PACKAGINGS Specifications for Containers for Motor Vehicle Transportation § 178.346 Specification DOT 406; cargo tank motor vehicle. ...

RELATIONS BETWEEN MOTORIC ABILITIES AND SPECIFIC MOTORIC BASKETBALL SKILLS IN PHYSICAL EDUCATION CLASSES

Directory of Open Access Journals (Sweden)

Dejan Milenković

2014-06-01

Full Text Available The aim of this study was to determine the relation between motoric and specific motoric basketball skills in physical education classes for elementary school students. The sample was taken from a population of boys and girls in four elementary schools in Niš. Boys (66 and girls (58, have been students of elementary school, 10 years old and all of them have been attending regular physical education classes three times a week. For the assessment of motoric abilities, a set of 12 motoric tests was applied: Explosive strength: squat jump, squat jump arms swing and drop jump; Speed: 20m running from a low start, orbiting hand and orbiting leg; Coordination: jumping over the horizontal rope, envelope test and figure „8“ with bending; Accuracy: darts, shooting with the ball at horizontal target and stiletto. For the assessment of specific motoric basketball skills a set of six tests was applied: elevations precision of ball passing with two hands, horizontal precision of  ball passing with two hands, orbiting ball around the body, orbiting ball through the legs (figure „8“, dribble around a central circle of the basketball court and dribble two "small eights" around two adjacent circles of basketball court. In data processing canonical correlation and regression analysis were used. The results showed that motoric abilities significantly contributed to success of specific motoric tests performance both with boys and also with girls.

Soft-Starting Power-Factor Motor Controller

Science.gov (United States)

Nola, F. J.

1983-01-01

Three-phase power-factor controller with soft start is based on earlier version that does not control starting transients. Additional components serve to turn off "run" command signal and substitute gradual startup command signal during preset startup interval. Improved controller reduces large current surge that usually accompanies starting. Controller applies power smoothly, without causing motor vibrations.

Power Requirements Determined for High-Power-Density Electric Motors for Electric Aircraft Propulsion

Science.gov (United States)

Johnson, Dexter; Brown, Gerald V.

2005-01-01

Future advanced aircraft fueled by hydrogen are being developed to use electric drive systems instead of gas turbine engines for propulsion. Current conventional electric motor power densities cannot match those of today s gas turbine aircraft engines. However, if significant technological advances could be made in high-power-density motor development, the benefits of an electric propulsion system, such as the reduction of harmful emissions, could be realized.

Controller for a High-Power, Brushless dc Motor

Science.gov (United States)

Fleming, David J.; Makdad, Terence A.

1987-01-01

Driving and braking torques controllable. Control circuit operates 7-kW, 45-lb-ft (61-N-m), three-phase, brushless dc motor in both motor and generator modes. In motor modes, energy from power source is pulse-width modulated to motor through modified "H-bridge" circuit, in generator mode, energy from motor is pulse-width modulated into bank of load resistors to provide variable braking torques. Circuit provides high-resolution torque control in both directions over wide range of speeds and torques. Tested successfully at bus voltages up to 200 Vdc and currents up to 45 A.

IEEE Std 649-1991: IEEE standard for qualifying Class 1E motor control centers for nuclear power generating stations

International Nuclear Information System (INIS)

Anon.

1993-01-01

The basic principles, requirements, and methods for qualifying Class 1E motor control centers for both harsh and mild environment applications in nuclear power generating stations are described. In addition to defining specific qualification requirements for Class 1E motor control centers and their components in accordance with the more general qualification requirements of IEEE Std 323-1983, this standard is intended to provide guidance in establishing a qualification program for demonstrating the adequacy of Class 1E motor control centers in nuclear power generating station applications

NASA Glenn Research Center Program in High Power Density Motors for Aeropropulsion

Science.gov (United States)

Brown, Gerald V.; Kascak, Albert F.; Ebihara, Ben; Johnson, Dexter; Choi, Benjamin; Siebert, Mark; Buccieri, Carl

2005-01-01

Electric drive of transport-sized aircraft propulsors, with electric power generated by fuel cells or turbo-generators, will require electric motors with much higher power density than conventional room-temperature machines. Cryogenic cooling of the motor windings by the liquid hydrogen fuel offers a possible solution, enabling motors with higher power density than turbine engines. Some context on weights of various systems, which is required to assess the problem, is presented. This context includes a survey of turbine engine weights over a considerable size range, a correlation of gear box weights and some examples of conventional and advanced electric motor weights. The NASA Glenn Research Center program for high power density motors is outlined and some technical results to date are presented. These results include current densities of 5,000 A per square centimeter current density achieved in cryogenic coils, finite element predictions compared to measurements of torque production in a switched reluctance motor, and initial tests of a cryogenic switched reluctance motor.

The effect of motor imagery with specific implement in expert badminton player.

Science.gov (United States)

Wang, Z; Wang, S; Shi, F-Y; Guan, Y; Wu, Y; Zhang, L-L; Shen, C; Zeng, Y-W; Wang, D-H; Zhang, J

2014-09-05

Motor skill can be improved with mental simulation. Implements are widely used in daily life and in various sports. However, it is unclear whether the utilization of implements enhances the effect of mental simulation. The present study was designed to investigate the different effects of motor imagery in athletes and novices when they handled a specific implement. We hypothesize that athletes have better motor imagery ability than novices when they hold a specific implement for the sport. This is manifested as higher motor cortical excitability in athletes than novices during motor imagery with the specific implement. Sixteen expert badminton players and 16 novices were compared when they held a specific implement such as a badminton racket and a non-specific implement such as a a plastic bar. Motor imagery ability was measured with a self-evaluation questionnaire. Transcranial magnetic stimulation was used to test the motor cortical excitability during motor imagery. Motor-evoked potentials (MEPs) in the first dorsal interosseous (FDI) and extensor carpi radialis muscles were recorded. Athletes reported better motor imagery than novices when they held a specific implement. Athletes exhibited more MEP facilitation than novices in the FDI muscle with the specific implement applied during motor imagery. The MEP facilitation is correlated with motor imagery ability in athletes. We conclude that the effects of motor imagery with a specific implement are enhanced in athletes compared to novices and the difference between two groups is caused by long-term physical training of athletes with the specific implement. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

Operation Characteristics Optimization of Low Power Three-Phase Asynchronous Motors

Directory of Open Access Journals (Sweden)

VLAD, I.

2014-02-01

Full Text Available Most published papers on low power asynchronous motors were aimed to achieve better operational performances in different operating conditions. The optimal design of the general-purpose motors requires searching and selecting an electric machine to meet minimum operating costs criterion and certain customer imposed restrictive conditions. In this paper, there are many significant simulations providing qualitative and quantitative information on reducing active and reactive energy losses in motors, and on parameters and constructive solution. The optimization study applied the minimal operating costs criterion, and it took into account the starting restrictive conditions. Thirteen variables regarding electromagnetic stresses and main constructive dimensions were considered. The operating costs of the optimized motor decreased with 25.6%, as compared to the existing solution. This paper can be a practical and theoretical support for the development and implementation of modern design methods, based on theoretical and experimental study of stationary and transient processes in low power motors, to increase efficiency and power factor.

RELATION BETWEEN LATENT SPECIFIC MOTOR ABILITIES AND SITUATION MOTOR SKILLS WITH VOLLEYBALL PLAYERS AGED FROM 16 TO 17

Directory of Open Access Journals (Sweden)

Rabit Veseli

2015-05-01

Full Text Available The game of volleyball with its dynamic character is present in the world of the sport with permanent development and growing popularity and fans. Volleyball is part of a pollystructural complex sports activities. It is performed on a ground of a relatively small size (18 x 9 meters and is a kind of game that requires of players a high level of advanced motoric abilities (speed, strength, endurance, a fast rate of visual reaction, explosivity, as well as specific motoric skills (precision etc.. Scientific conclusion as well as the growing number of conducted researches in the very game, have a real contribution to its modern development and level of popularity. Situation-motoric skills make a significant dimension in the structure of volleyball game. The subject of the research is specific-motoric abilities and situation-motoric skills of 52 volleyball players aged from 16 to 17. The basic goal of the research is to establish the effect of specific-motoric abilities on situation-motoric skills of volleyball players in latent space. In order to assess the specific-motoric abilities 9 tests are used, and to assess the situation-motoric skills 3 precision tests are used. The results obtained from the 12 applied tests are worked out through the basic statistic parameters. Through component factor analysis 3 latent specific-motoric dimensions are isolated as well as one situation-motoric dimension. By regressive analysis there is established a low but statistically significant relation between the criterion and predictor latent dimensions. That confirms the dependence and relation between the specific-motoric abilities and situation-motoric skills. Researches in the fi eld of similar questions have been conducted by the following authors: Jurko et al., 2013 and Nešić, et al., 2011.

ANALYSIS OF RELATIONS BETWEEN JUDO TECHNIQUES AND SPECIFIC MOTOR ABILITIES

Directory of Open Access Journals (Sweden)

Patrik Drid

2006-06-01

Full Text Available Specific physical preparation affects the development of motor abilities required for execution of specific movements in judo. When selecting proper specific exercises for judo for a target motor ability, it is necessary to precede it with the study of the structure of specific judo techniques and activities of individual muscle groups engaged for execution of the technique. On the basis of this, one can understand which muscles are most engaged during realization of individual techniques, which serves as a standpoint for selection of a particular complex of specific exercises to produce the highest effects. In addition to the development of particular muscle groups, the means of specific preparation will take effect on the development of those motor abilities which are evaluated as the indispensable for the development of particular qualities which are characteristic for judo. This paper analyses the relationship between judo techniques field and specific motor abilities.

Starting characteristics of direct current motors powered by solar cells

Science.gov (United States)

Singer, S.; Appelbaum, J.

1989-01-01

Direct current motors are used in photovoltaic systems. Important characteristics of electric motors are the starting to rated current and torque ratios. These ratios are dictated by the size of the solar cell array and are different for the various dc motor types. Discussed here is the calculation of the starting to rated current ratio and starting to rated torque ratio of the permanent magnet, and series and shunt excited motors when powered by solar cells for two cases: with and without a maximum-power-point-tracker (MPPT) included in the system. Comparing these two cases, one gets a torque magnification of about 3 for the permanent magnet motor and about 7 for other motor types. The calculation of the torques may assist the PV system designer to determine whether or not to include an MPPT in the system.

Analysis of Valve Requirements for High-Efficiency Digital Displacement Fluid Power Motors

DEFF Research Database (Denmark)

Rømer, Daniel; Johansen, Per; Pedersen, Henrik C.

2013-01-01

Digital displacement fluid power motors have been shown to enable high-efficiency operation in a wide operation range, including the part load range where conventional fluid power motors suffers from poor efficiencies. The use of these digital displacement motors set new requirements for the valve...... transition time and flow-pressure coefficient are normalized, leading to a presentation of the general efficiency map of the digital displacement motor. Finally the performance of existing commercial valves with respect to digital motors is commented....

Advanced Power Electronics and Electric Motors Annual Report -- 2013

Energy Technology Data Exchange (ETDEWEB)

Narumanchi, S. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Bennion, K. [National Renewable Energy Lab. (NREL), Golden, CO (United States); DeVoto, D. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Moreno, G. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Rugh, J. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Waye, S. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2015-01-01

This report describes the research into advanced liquid cooling, integrated power module cooling, high temperature air cooled power electronics, two-phase cooling for power electronics, and electric motor thermal management by NREL's Power Electronics group in FY13.

Magnification of starting torques of dc motors by maximum power point trackers in photovoltaic systems

Science.gov (United States)

Appelbaum, Joseph; Singer, S.

1989-01-01

Direct current (dc) motors are used in terrestrial photovoltaic (PV) systems such as in water-pumping systems for irrigation and water supply. Direct current motors may also be used for space applications. Simple and low weight systems including dc motors may be of special interest in space where the motors are directly coupled to the solar cell array (with no storage). The system will operate only during times when sufficient insolation is available. An important performance characteristic of electric motors is the starting to rated torque ratio. Different types of dc motors have different starting torque ratios. These ratios are dictated by the size of solar cell array, and the developed motor torque may not be sufficient to overcome the load starting torque. By including a maximum power point tracker (MPPT) in the PV system, the starting to rated torque ratio will increase, the amount of which depends on the motor type. The starting torque ratio is calculated for the permanent magnet, series and shunt excited dc motors when powered by solar cell arrays for two cases: with and without MPPT's. Defining a motor torque magnification by the ratio of the motor torque with an MPPT to the motor torque without an MPPT, a magnification of 3 was obtained for the permanent magnet motor and a magnification of 7 for both the series and shunt motors. The effect of the variation of solar insolation on the motor starting torque was covered. All motor types are less sensitive to insolation variation in systems including MPPT's as compared to systems with MPPT's. The analysis of this paper will assist the PV system designed to determine whether or not to include an MPPT in the system for a specific motor type.

Dual power, constant speed electric motor system

Science.gov (United States)

Kirschbaum, H.S.

1984-07-31

A dual capacity permanent split capacitor electric motor system is provided with a stator having main and auxiliary windings. The main stator winding includes two winding sections which are connected in parallel with each other and across a pair of line terminals while the auxiliary winding is connected in series with a capacitor to form a circuit branch which is connected between the line terminals for operation at a first output power level. Switching means are provided to reconnect the main stator winding sections in series with each other and in series with a second capacitor to form a circuit branch which is connected between the line terminals while the stator auxiliary winding is connected directly between the line terminals for operation at a second output power level. Automatic rotation reversal occurs when the motor switches from the first to the second output power level. 6 figs.

Dual power, constant speed electric motor system

Science.gov (United States)

Kirschbaum, Herbert S.

1984-01-01

A dual capacity permanent split capacitor electric motor system is provided with a stator having main and auxiliary windings. The main stator winding includes two winding sections which are connected in parallel with each other and across a pair of line terminals while the auxiliary winding is connected in series with a capacitor to form a circuit branch which is connected between the line terminals for operation at a first output power level. Switching means are provided to reconnect the main stator winding sections in series with each other and in series with a second capacitor to form a circuit branch which is connected between the line terminals while the stator auxiliary winding is connected directly between the line terminals for operation at a second output power level. Automatic rotation reversal occurs when the motor switches from the first to the second output power level.

Study on Power Switching Process of a Hybrid Electric Vehicle with In-Wheel Motors

Directory of Open Access Journals (Sweden)

Shaohua Wang

2016-01-01

Full Text Available Hybrid electric vehicles with in-wheel motors (IWM achieve a variety of driving modes by two power sources—the engine and the IWM. One of the critical problems that exists in such vehicle is the different transient characteristics between the engine and the IWM. Therefore, switching processes between the power sources have noteworthy impacts on vehicle dynamics and driving performance. For the particular switching process of the pure electric mode to the engine driving mode, a specific control strategy coordinating clutch torque, motor torque, and engine torque was proposed to solve drivability issues caused by inconsistent responses of different power sources during the mode transition. The specific switching process could be described as follows: the engine was started by IWM with the clutch serving as a key enabling actuator, dynamic torque compensation through IWM was implemented after engine started, and, meanwhile, engine speed was controlled to track the target speed through the closed loop PID control strategy. The bench tests results showed that the vehicle jerk caused during mode switching was reduced and fast and smooth mode switching was realized, which leads to the improvement of vehicle’s riding comfort.

Improved transistorized AC motor controller for battery powered urban electric passenger vehicles

Science.gov (United States)

Peak, S. C.

1982-01-01

An ac motor controller for an induction motor electric vehicle drive system was designed, fabricated, tested, evaluated, and cost analyzed. A vehicle performance analysis was done to establish the vehicle tractive effort-speed requirements. These requirements were then converted into a set of ac motor and ac controller requirements. The power inverter is a three-phase bridge using power Darlington transistors. The induction motor was optimized for use with an inverter power source. The drive system has a constant torque output to base motor speed and a constant horsepower output to maximum speed. A gear shifting transmission is not required. The ac controller was scaled from the base 20 hp (41 hp peak) at 108 volts dec to an expanded horsepower and battery voltage range. Motor reversal was accomplished by electronic reversal of the inverter phase sequence. The ac controller can also be used as a boost chopper battery charger. The drive system was tested on a dynamometer and results are presented. The current-controlled pulse width modulation control scheme yielded improved motor current waveforms. The ac controller favors a higher system voltage.

Reluctance motor of new design with improved efficiency and power factor

Energy Technology Data Exchange (ETDEWEB)

Hansen-Goos, P; Pieper, W

1981-09-01

Improvement of operating conditions and efficiency by development of new configurations of lamination and production methods for reluctance motors. Investigations during the starting-up period and of the operating behaviour in connection with variable frequency. Reluctance motors are designed in the range from 0,6-4kW with 4-pole winding. They are due to the following identification: 1. The power of motors is in accordance with VDE 42673. 2. The volume of lamination is equal to asynchronous motors of the same IED size. 3. Synchronous pull-out torque is in compliance with VDE 0530: Msub(K)sub(S) > 1,35 Mn (nominal torque). As against standard reluctance motors the following improvements with the new ones have been realized: 4. Increase of nominal power by approx. 100%. 5. Increase of quality factor by approx. 50%. 6. The efficiency is equal to asynchronous motors of the same IEC size.

Improving motor reliability in nuclear power plants: Volume 2, Functional indicator tests on a small electric motor subjected to accelerated aging

International Nuclear Information System (INIS)

Subudhi, M.; Taylor, J.H.; Lofaro, R.; Sugarman, A.C.; Sheets, M.W.; Skreiner, K.M.

1987-11-01

A ten horsepower electric motor was artificially aged by plug reverse cycling for test purposes. The motor was manufactured in 1967 and was in service at a commercial nuclear power plant for twelve years. Various tests were performed on the motor throughout the aging process. The motor failed after 3.79 million reversals (3 seconds per reversal) over seven months of testing. Each test parameter was trended to assess its suitability in monitoring aging and service wear degradation in motors. Results and conclusions are discussed relative to the applicability of the tests performed to nuclear power plant motor maintenance programs. 15 refs., 28 figs., 1 tab

GDE2 regulates subtype-specific motor neuron generation through inhibition of Notch signaling.

Science.gov (United States)

Sabharwal, Priyanka; Lee, Changhee; Park, Sungjin; Rao, Meenakshi; Sockanathan, Shanthini

2011-09-22

The specification of spinal interneuron and motor neuron identities initiates within progenitor cells, while motor neuron subtype diversification is regulated by hierarchical transcriptional programs implemented postmitotically. Here we find that mice lacking GDE2, a six-transmembrane protein that triggers motor neuron generation, exhibit selective losses of distinct motor neuron subtypes, specifically in defined subsets of limb-innervating motor pools that correlate with the loss of force-generating alpha motor neurons. Mechanistically, GDE2 is expressed by postmitotic motor neurons but utilizes extracellular glycerophosphodiester phosphodiesterase activity to induce motor neuron generation by inhibiting Notch signaling in neighboring motor neuron progenitors. Thus, neuronal GDE2 controls motor neuron subtype diversity through a non-cell-autonomous feedback mechanism that directly regulates progenitor cell differentiation, implying that subtype specification initiates within motor neuron progenitor populations prior to their differentiation into postmitotic motor neurons. Copyright © 2011 Elsevier Inc. All rights reserved.

Motor-Generator powering the PS (Proton Synchrotron) main magnets

CERN Multimedia

1983-01-01

This motor-generator,30 MW peak, 1500 r.p.m.,pulsed power supply for the PS main magnet replaced in 1968 the initial 3000 r.p.m. motor-generator-flywheel set which had served from the PS start-up in 1959 until end 1967. See also photo 8302337 and its abstract.

Effect of different methods of pulse width modulation on power losses in an induction motor

Science.gov (United States)

Gulyaev, Alexander; Fokin, Dmitrii; Shuharev, Sergey; Ten, Evgenii

2017-10-01

We consider the calculation of modulation power losses in a system “induction motor-inverter” for various pulse width modulation (PWM) methods of the supply voltage. Presented values of modulation power losses are the result of modeling a system “DC link - two-level three-phase voltage inverter - induction motor - load”. In this study the power losses in a system “induction motor - inverter” are computed, as well as losses caused by higher harmonics of PWM supply voltage, followed by definition of active power consumed by the DC link for a specified value mechanical power on the induction motor shaft. Mechanical power was determined by the rotation speed and the torque on the motor shaft in various quasi-sinusoidal supply voltage PWM modes. These calculations reveal the best coefficient of performance (COP) in a system of a variable frequency drive (VFD) with independent voltage inverter controlled by induction motor PWM.

Optogenetically enhanced axon regeneration: motor versus sensory neuron-specific stimulation.

Science.gov (United States)

Ward, Patricia J; Clanton, Scott L; English, Arthur W

2018-02-01

Brief neuronal activation in injured peripheral nerves is both necessary and sufficient to enhance motor axon regeneration, and this effect is specific to the activated motoneurons. It is less clear whether sensory neurons respond in a similar manner to neuronal activation following peripheral axotomy. Further, it is unknown to what extent enhancement of axon regeneration with increased neuronal activity relies on a reflexive interaction within the spinal circuitry. We used mouse genetics and optical tools to evaluate the precision and selectivity of system-specific neuronal activation to enhance axon regeneration in a mixed nerve. We evaluated sensory and motor axon regeneration in two different mouse models expressing the light-sensitive cation channel, channelrhodopsin (ChR2). We selectively activated either sensory or motor axons using light stimulation combined with transection and repair of the sciatic nerve. Regardless of genotype, the number of ChR2-positive neurons whose axons had regenerated successfully was greater following system-specific optical treatment, with no effect on the number of ChR2-negative neurons (whether motor or sensory neurons). We conclude that acute system-specific neuronal activation is sufficient to enhance both motor and sensory axon regeneration. This regeneration-enhancing effect is likely cell autonomous. © 2018 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

Motor starting a Brayton cycle power conversion system using a static inverter

Science.gov (United States)

Curreri, J. S.; Edkin, R. A.; Kruchowy, R.

1973-01-01

The power conversion module of a 2- to 15-kWe Brayton engine was motor started using a three-phase, 400-hertz static inverter as the power source. Motor-static tests were conducted for initial gas loop pressures of 10, 14, and 17 N/sq cm (15, 20, and 25 psia) over a range of initial turbine inlet temperatures from 366 to 550 K (200 to 530 F). The data are presented to show the effects of temperature and pressure on the motor-start characteristics of the rotating unit. Electrical characteristics during motoring are also discussed.

Improved SCR ac Motor Controller for Battery Powered Urban Electric Vehicles

Science.gov (United States)

Latos, T. S.

1982-01-01

An improved ac motor controller, which when coupled to a standard ac induction motor and a dc propulsion battery would provide a complete electric vehicle power train with the exception of the mechanical transmission and drive wheels was designed. In such a system, the motor controller converts the dc electrical power available at the battery terminals to ac electrical power for the induction motor in response to the drivers commands. The performance requirements of a hypothetical electric vehicle with an upper weight bound of 1590 kg (3500 lb) were used to determine the power rating of the controller. Vehicle acceleration capability, top speed, and gradeability requisites were contained in the Society of Automotive Engineers (SAE) Schedule 227a(d) driving cycle. The important capabilities contained in this driving cycle are a vehicle acceleration requirement of 0 to 72.4 kmph (0 to 45 mph) in 28 seconds a top speed of 88.5 kmph (55 mph), and the ability to negotiate a 10% grade at 48 kmph (30 mph). A 10% grade is defined as one foot of vertical rise per 10 feet of horizontal distance.

High power density superconducting motor for control applications

International Nuclear Information System (INIS)

Lopez, J; Granados, X; Lloberas, J; Torres, R; Grau, J; Maynou, R; Bosch, R

2008-01-01

A high dynamics superconducting low power motor for control applications has been considered for design. The rotor is cylindrical with machined bulks that generate the field by trapping flux in a four poles configuration. The toothless iron armature is wound by copper, acting iron only as magnetic screen. Details of the magnetic assembling, cryogenics and electrical supply conditioning will be reported. Improvements due to the use of a superconducting set are compared with performances of equivalent conventional motors

GROUNDING THE REDUCTION OF POWER OF THE HYDRAULIC DRIVE ELECTRIC MOTOR BY EQUIVALENT POWER METHOD

Directory of Open Access Journals (Sweden)

O. Hrygorov

2017-06-01

Full Text Available The authors have analyzed the power consumption by a hydraulic drive and wound rotor motor of crane mechanisms at all stages of the operational cycle: acceleration, movement at nominal or intermediate speed and deceleration. The decrease of the rated capacity of electric motors is justified.

Thermal Management of Power Electronics and Electric Motors for Electric-Drive Vehicles (Presentation)

Energy Technology Data Exchange (ETDEWEB)

Narumanchi, S.

2014-09-01

This presentation is an overview of the power electronics and electric motor thermal management and reliability activities at NREL. The focus is on activities funded by the Department of Energy Vehicle Technologies Office Advanced Power Electronics and Electric Motors Program.

The relationships between gross motor coordination and sport-specific skills in adolescent non-athletes

Directory of Open Access Journals (Sweden)

Chagas Daniel V

2017-12-01

Full Text Available Purpose. While the usefulness of gross motor coordination score as predictor of sports performance in young athletes has been demonstrated, practical applications in the settings where the focus is not on elite performance is limited. Further, little is known about the extent to which gross motor coordination score is associated with sport-specific skills among adolescent nonathletes. The aim of this study was to analyse the relationship between the degree of gross motor coordination and execution in specific volleyball tests among adolescent non-athletes. Methods. The total of 34 students (27 females and 7 males aged 13-14 years who regularly participated in volleyball during physical education classes were randomly recruited. Gross motor coordination was assessed with the Körperkoordinationstest für Kinder. Motor performance on volley-specific skills was indicated by two product-oriented tasks: volleyball under service and service reception. Correlation and linear regression analyses were applied to examine the associations between motor coordination scores and motor performance in volley-specific skills. Results. Motor coordination score was positively correlated with motor performance on specific skills (r = 0.503, p = 0.02. Linear regression analysis revealed that motor coordination score accounted for 23% of the variance in the motor performance on volleyball skills (R2 = 0.253, R2 adjusted = 0.230, F = 10.836, p = 0.02. Conclusions. The degree of gross motor coordination seems to play a significant role in the execution of specific volleyball tasks.

Effect of power quality on windings temperature of marine induction motors

Energy Technology Data Exchange (ETDEWEB)

Gnacinski, P. [Gdynia Maritime University, Department of Ship Electrical Power Engineering, Morska Str. 83, 81-225 Gdynia (Poland)], E-mail: piotrg@am.gdynia.pl

2009-10-15

Marine induction machines are exposed to various power quality disturbances appearing simultaneously in ship power systems: frequency and voltage rms value deviation, voltage unbalance and voltage waveform distortions. As a result, marine induction motors can be seriously overheated due to lowered supply voltage quality. Improvement of the protection of marine induction machines requires an appropriate method of power quality assessment and modification of the power quality regulations of ship classification societies. This paper presents an analytical model of an induction cage machine supplied with voltage of lowered quality, used in part II of the work (effect of power quality on windings temperature of marine induction motors. Part II. Results of investigations and recommendations for related regulations) for power quality assessment in ship power systems, and for justification of the new power quality regulations proposal. The presented model is suitable for implementation in an on-line measurement system.

Higher Efficiency HVAC Motors

Energy Technology Data Exchange (ETDEWEB)

Flynn, Charles Joseph [QM Power, Inc., Kansas City, MO (United States)

2018-02-13

The objective of this project was to design and build a cost competitive, more efficient heating, ventilation, and air conditioning (HVAC) motor than what is currently available on the market. Though different potential motor architectures among QMP’s primary technology platforms were investigated and evaluated, including through the building of numerous prototypes, the project ultimately focused on scaling up QM Power, Inc.’s (QMP) Q-Sync permanent magnet synchronous motors from available sub-fractional horsepower (HP) sizes for commercial refrigeration fan applications to larger fractional horsepower sizes appropriate for HVAC applications, and to add multi-speed functionality. The more specific goal became the research, design, development, and testing of a prototype 1/2 HP Q-Sync motor that has at least two operating speeds and 87% peak efficiency compared to incumbent electronically commutated motors (EC or ECM, also known as brushless direct current (DC) motors), the heretofore highest efficiency HVACR fan motor solution, at approximately 82% peak efficiency. The resulting motor prototype built achieved these goals, hitting 90% efficiency and .95 power factor at full load and speed, and 80% efficiency and .7 power factor at half speed. Q-Sync, developed in part through a DOE SBIR grant (Award # DE-SC0006311), is a novel, patented motor technology that improves on electronically commutated permanent magnet motors through an advanced electronic circuit technology. It allows a motor to “sync” with the alternating current (AC) power flow. It does so by eliminating the constant, wasteful power conversions from AC to DC and back to AC through the synthetic creation of a new AC wave on the primary circuit board (PCB) by a process called pulse width modulation (PWM; aka electronic commutation) that is incessantly required to sustain motor operation in an EC permanent magnet motor. The Q-Sync circuit improves the power factor of the motor by removing all

Simple Power Control for Sensorless Induction Motor Drives Fed by a Matrix Converter

DEFF Research Database (Denmark)

Blaabjerg, Frede; Lee, Kyo Beum

2008-01-01

This paper presents a new and simple method for sensorless control of matrix converter drives using a power flowing to the motor. The proposed control algorithm is based on controlling the instantaneous real and imaginary powers into the induction motor. To improve low-speed sensorless performance...

Design and Performance Test of Axial Halbach Brushless DC Motor with Power Density 1.5 Kw/Kg

Directory of Open Access Journals (Sweden)

Kevin Dwi Prasetio

2017-01-01

Full Text Available Progress of technology on electric vehicle component sector is one reason the emergence of electric vehicles at the moment. Starting from battery which has a great current density up to the automatic control systems on electric vehicles. But there are still some shortcomings of this electric vehicle components, one of which is the low value of power density of existing electric motor in the market today.On vehicles such as electric cars when Race Car Contest, energy saving problems about power density of the driving motor is very vital. This is because the total weight of the vehicle has a huge influence on the vehicle efficiency is against it. The issue is one of the reasons of the research task. In this final task is done making the design, simulation, and architecture of the Axial Halbach Brushless DC Motor. Use of system configuration on the halbach magnet to avoid the use of iron as a material cantilever rotor. By changing the material of the cantilever rotor with lighter materials such as aluminum or even carbon fibre, the value of power density electric motors can be increased. Then using the litz wire on coil stator to reduce loss-power loss due to the barriers on the coil. Coreless stator on the system and to avoid the phenomenon of cogging at the time due to low rpm style attraction magnet with iron in the core material. While the creation process begins by determining the specifications of the Axial Halbach Brushless DC motors. Then go into the design phase of the mechanical and electrical design. Who then conducted simulations to help determine other parameters such as air gap, slot turn, and magnetic orientation. The process of making a component of stator and rotor after the simulation is completed. After all the components of the rotor and stator on assembly, mounting the hall sensor is carried out to the right to position obtained by reading the signals. After the motor can spin with good motor performance, testing can be done

Study of data transmission over drive motor power cables of a remotely operated robot using power line communication technology

International Nuclear Information System (INIS)

Balaji, Kanchi; Singh, Ashutosh Pratap; Rakesh, V.; Rajagopalan, C.; Murugan, S.

2016-01-01

In nuclear power plants (NPPs), robotic devices are widely used for carrying out in-service inspection (lSI) and repair tasks at elevated temperatures and radiation environments. These devices comprises servo motors that are powered and controlled by the motion control unit/electric drives. The control and inspection data are to be transmitted back from the inspection device to the control unit using separate industrial graded data transmission cables compatible for high temperature applications. This increases complexity of robot trailing cables and cost. Hence, it is proposed to use power cables that are used for powering the motor for sending information signals using power line communication (PLC) technology. The domestically used PLC modems adds noise to the information signal when coupled on to the motor feed cables during IGBT switching. Therefore, passive low pass filters are used at the motor drive end to reduce the impulsive noise. The aim of this study is to compare noise characteristics for different type of filter structures over pulse width modulation (PWM) network. We will highlight the choice of cut off frequency of filter based on frequency of information signal

Magnification of starting torques of dc motors by maximum power point trackers in photovoltaic systems

Science.gov (United States)

Appelbaum, J.; Singer, S.

1989-01-01

A calculation of the starting torque ratio of permanent magnet, series, and shunt-excited dc motors powered by solar cell arrays is presented for two cases, i.e., with and without a maximum-power-point tracker (MPPT). Defining motor torque magnification by the ratio of the motor torque with an MPPT to the motor torque without an MPPT, a magnification of 3 for the permanent magnet motor and a magnification of 7 for both the series and shunt motors are obtained. The study also shows that all motor types are less sensitive to solar insolation variation in systems including MPPTs as compared to systems without MPPTs.

Perancangan Zeta Converter yang dilengkapi Power Factor Correction pada Aplikasi Pengaturan Kecepatan Motor Brushless DC

Directory of Open Access Journals (Sweden)

Adhika Prajna Nandiwardhana

2017-01-01

Full Text Available Penggunaan motor brushless DC telah banyak digunakan dalam berbagai bidang seperti peralatan rumah tangga maupun industri dikarenakan motor ini memiliki struktur yang sederhana, efisiensi dan torsi yang tinggi, serta menggunakan konsep komutasi elektris yang berbeda dari motor DC lainnya. Namun pengoperasian pada umumnya yang menggunakan sumber AC, penyearah serta inverter membuat tingginya nilai harmonisa arus (THD sebesar 73,33% dan power factor sebesar 0,803 dimana nilai ini kurang baik dalam pengaplikasiannya. Pada penelitian ini akan dikaji mengenai proses power factor correction yang mereduksi harmonisa arus (THD sumber AC dengan menggunakan zeta converter dalam pengaplikasian motor brushless DC, serta pengoperasian motor dengan mengamati respon motor terhadap kecepatan referensi yang berubah-ubah dan mengamati kestabilan motor terhadap pembebanan yang bervariasi. Dalam menerapkan metode yang dilakukan pada penelitian ini, pengoperasian motor brushless DC yang telah dirancang dapat bekerja dengan baik meliputi respon motor yang dapat mengikuti kecepatan referensi yang berubah-ubah, serta kestabilan motor dalam mempertahankan kecepatannya pada pembebanan yang bervariasi. Proses power factor correction dapat meningkatkan kualitas daya pada berbagai kecepatan dan mode penerapan yang berbeda-beda, dimana peningkatan tersebut membuktikan kinerja yang baik dalam sistem ini dan memiliki nilai kualitas daya yang baik.

The main pump motor remote visual check in the application of the domestic nuclear power plants

International Nuclear Information System (INIS)

Ge Lianwei; Yu Tao; Fang Jiang; Zhang Ting; Zhang Xingtian; Ding Youyuan

2014-01-01

In this paper, the Qinshan nuclear power station the first main pump motor to the successful implementation of remote visual inspection the main pump motor remote visual inspection applications. Qinshan Nuclear Power Plant Units 1 and 2 of the main pump motor inspection results show that the key components of the Qinshan Nuclear Power Plant Units 1 and 2 of the main pump rotor, stator end coils good condition, its problems for 10 years in the motor does not affect the normal use of the motor state disintegration overhaul problems tracking disintegration overhaul in 10 years. (authors)

Dynamic modeling of brushless dc motor-power conditioner unit for electromechanical actuator application

Science.gov (United States)

Demerdash, N. A.; Nehl, T. W.

1979-01-01

A comprehensive digital model for the analysis of the dynamic-instantaneous performance of a power conditioner fed samarium-cobalt permanent magnet brushless DC motor is presented. The particular power conditioner-machine system at hand, for which this model was developed, is a component of an actual prototype electromechanical actuator built for NASA-JSC as a possible alternative to hydraulic actuators as part of feasibility studies for the shuttle orbiter applications. Excellent correlation between digital simulated and experimentally obtained performance data was achieved for this specific prototype. This is reported on in this paper. Details of one component of the model, its applications and the corresponding results are given in this paper.

Real-Time Monitoring and Fault Diagnosis of a Low Power Hub Motor Using Feedforward Neural Network

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Mehmet Şimşir

2016-01-01

Full Text Available Low power hub motors are widely used in electromechanical systems such as electrical bicycles and solar vehicles due to their robustness and compact structure. Such systems driven by hub motors (in wheel motors encounter previously defined and undefined faults under operation. It may inevitably lead to the interruption of the electromechanical system operation; hence, economic losses take place at certain times. Therefore, in order to maintain system operation sustainability, the motor should be precisely monitored and the faults are diagnosed considering various significant motor parameters. In this study, the artificial feedforward backpropagation neural network approach is proposed to real-time monitor and diagnose the faults of the hub motor by measuring seven main system parameters. So as to construct a necessary model, we trained the model, using a data set consisting of 4160 samples where each has 7 parameters, by the MATLAB environment until the best model is obtained. The results are encouraging and meaningful for the specific motor and the developed model may be applicable to other types of hub motors. The prosperous model of the whole system was embedded into Arduino Due microcontroller card and the mobile real-time monitoring and fault diagnosis system prototype for hub motor was designed and manufactured.

Induction generator-induction motor wind-powered pumping system

Energy Technology Data Exchange (ETDEWEB)

Miranda, M.S.; Lyra, R.O.C.; Silva, S.R. [CPDEE - UFMG, Belo Horizonte (Brazil)

1997-12-31

The energy storage matter plays an important role in wind-electric conversion systems for isolated applications. Having that in mind, two different approaches can be basically considered: either the immediate conversion of the generated electric energy, as in a water pumping system or electric energy storage for later use, as in a battery charging system. Due to some features such as no need of an external reactive power source and, sometimes, a gearbox, permanent-magnet synchronous generators have been broadly used in low rated power isolated systems. Despite that, system performance can be affected when the generator is feeding an inductive load (e.g., an induction motor) under variable-speed-variable-frequency operational conditions. Since there is no effective flux control, motor overload may occur at high wind speeds. Thus, good system performance can be obtained through additional control devices which may increase system cost. Although being rugged and cheap, induction machines always work as a reactive power drain; therefore, they demand an external reactive power source. Considering that, reactive static compensators appear as an attractive alternative to the cost x performance problem. In addition to that, different control strategies can be used so that system performance can be improved.

MECHANICAL CHARACTERISTICS OF THREE-PHASE INDUCTION MOTORS WITH SINGLE-PHASE POWER SUPPLY

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V.S. Malyar

2016-06-01

Full Text Available Aim. Development of a method for calculating mechanical characteristics of three-phase induction motors with single-phase power supply. Methods. The developed algorithm is based on the high-adequacy mathematical model of motor and projection method for solving the boundary problem for equations of electrical circuits balance presented in the three-phase coordinate system. As a result of asymmetry of power supply to the stator windings, in steady state, flux-linkage and current change according to the periodic law. They are determined by solving the boundary problem. Results. The developed mathematical model allows determining periodic dependence of coordinates as a function of slip and, based on them, mechanical characteristics of motors. Academic novelty. The developed method relies on a completely new mathematical approach to calculation of stationary modes of nonlinear electromagnetic circuits, which allows obtaining periodic solution in a timeless domain. Practical value. Using the developed calculation algorithm, one can select capacitance required to start an induction motor with single-phase power supply and calculate static mechanical characteristics at a given capacitance.

Four giga joule flywheel motor-generator for JT-60 toroidal field coil power supply system

International Nuclear Information System (INIS)

Matsukawa, T.; Kanke, M.; Shimada, R.; Yoshida, Y.; Yamashita, K.; Nakayama, T.

1986-01-01

A fusion test reactor often needs motor-generators as a power source in order to reduce disturbances to utility lines. The toroidal field coil power supply system of JT-60 also adopted a motor-generator for this purpose. The motor-generator started operation in April, 1985 at Japan Atomic Energy Research Institute together with the whole system. The motor-generator has several special features both electrically and mechanically. One electrical feature is that it is used as a pulse source of large current and power for periodic short-time duty. A mechanical feature is that a large flywheel is directly coupled to the motor-generator shaft and operated intermittently and at high speed. Therefore detailed investigations were carried out concerning constitution, characteristics as well as the coordination with the system performance. This paper describes the outlines of the flywheel motor-generator and discusses several topics

Area-specific temporal control of corticospinal motor neuron differentiation by COUP-TFI

Science.gov (United States)

Tomassy, Giulio Srubek; De Leonibus, Elvira; Jabaudon, Denis; Lodato, Simona; Alfano, Christian; Mele, Andrea; Macklis, Jeffrey D.; Studer, Michèle

2010-01-01

Transcription factors with gradients of expression in neocortical progenitors give rise to distinct motor and sensory cortical areas by controlling the area-specific differentiation of distinct neuronal subtypes. However, the molecular mechanisms underlying this area-restricted control are still unclear. Here, we show that COUP-TFI controls the timing of birth and specification of corticospinal motor neurons (CSMN) in somatosensory cortex via repression of a CSMN differentiation program. Loss of COUP-TFI function causes an area-specific premature generation of neurons with cardinal features of CSMN, which project to subcerebral structures, including the spinal cord. Concurrently, genuine CSMN differentiate imprecisely and do not project beyond the pons, together resulting in impaired skilled motor function in adult mice with cortical COUP-TFI loss-of-function. Our findings indicate that COUP-TFI exerts critical areal and temporal control over the precise differentiation of CSMN during corticogenesis, thereby enabling the area-specific functional features of motor and sensory areas to arise. PMID:20133588

FY2011 Advanced Power Electronics and Electric Motors Annual Progress Report

Energy Technology Data Exchange (ETDEWEB)

Rogers, Susan A. [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States)

2012-01-31

The Advanced Power Electronics and Electric Motors (APEEM) program within the DOE Vehicle Technologies Program (VTP) provides support and guidance for many cutting-edge automotive technologies now under development. Research is focused on developing revolutionary new power electronics (PE), electric motor (EM), thermal management, and traction drive system technologies that will leapfrog current on-the-road technologies. The research and development (R&D) is also aimed at achieving a greater understanding of and improvements in the way the various new components of tomorrow’s automobiles will function as a unified system to improve fuel efficiency.

Limitations of the Conventional Phase Advance Method for Constant Power Operation of the Brushless DC Motor

International Nuclear Information System (INIS)

Lawler, J.S.

2001-01-01

The brushless dc motor (BDCM) has high-power density and efficiency relative to other motor types. These properties make the BDCM well suited for applications in electric vehicles provided a method can be developed for driving the motor over the 4 to 6:1 constant power speed range (CPSR) required by such applications. The present state of the art for constant power operation of the BDCM is conventional phase advance (CPA)[1]. In this paper, we identify key limitations of CPA. It is shown that the CPA has effective control over the developed power but that the current magnitude is relatively insensitive to power output and is inversely proportional to motor inductance. If the motor inductance is low, then the rms current at rated power and high speed may be several times larger than the current rating. The inductance required to maintain rms current within rating is derived analytically and is found to be large relative to that of BDCM designs using high-strength rare earth magnets. Th us, the CPA requires a BDCM with a large equivalent inductance

Motor power calculation for driving conveyor chain in gamma irradiator BATAN 2x250 k curie

International Nuclear Information System (INIS)

Ari Satmoko; Syamsurrijal Ramdja; Sutomo Budihardjo

2010-01-01

Recently, an Irradiator BATAN 2X250 k Curie for agricultural product is under design. The installation is provided by the gamma source about 2x250 k Curie. Agricultural products are carried into carriers and these carriers are hanged on the conveyor chain. The chain moves into a radiation chamber following the trajectoire. The chain is drived by motor. For this reason, the calculation is performed to determine the motor power. After resolving the force equilibrium equation, the force and power of the motor needed to drive the chain are obtained. Numerical method by using V Basic language is used to resolve the equation. The calculation result shows the correlation between friction coefficient and motor power. From the evaluation, it is decided that the friction coefficient should be less than 0,015. By this friction, the motor power is about 3. 13 k Watt. From the evaluation, it is also obtained that the radius of the curve trajectory shall not be too small. Combination between high friction and small curve radius could lead to the locked condition in which high power motor are not be able to move the conveyor chain). (author)

Increased gamma band power during movement planning coincides with motor memory retrieval.

Science.gov (United States)

Thürer, Benjamin; Stockinger, Christian; Focke, Anne; Putze, Felix; Schultz, Tanja; Stein, Thorsten

2016-01-15

The retrieval of motor memory requires a previous memory encoding and subsequent consolidation of the specific motor memory. Previous work showed that motor memory seems to rely on different memory components (e.g., implicit, explicit). However, it is still unknown if explicit components contribute to the retrieval of motor memories formed by dynamic adaptation tasks and which neural correlates are linked to memory retrieval. We investigated the lower and higher gamma bands of subjects' electroencephalography during encoding and retrieval of a dynamic adaptation task. A total of 24 subjects were randomly assigned to a treatment and control group. Both groups adapted to a force field A on day 1 and were re-exposed to the same force field A on day 3 of the experiment. On day 2, treatment group learned an interfering force field B whereas control group had a day rest. Kinematic analyses showed that control group improved their initial motor performance from day 1 to day 3 but treatment group did not. This behavioral result coincided with an increased higher gamma band power in the electrodes over prefrontal areas on the initial trials of day 3 for control but not treatment group. Intriguingly, this effect vanished with the subsequent re-adaptation on day 3. We suggest that improved re-test performance in a dynamic motor adaptation task is contributed by explicit memory and that gamma bands in the electrodes over the prefrontal cortex are linked to these explicit components. Furthermore, we suggest that the contribution of explicit memory vanishes with the subsequent re-adaptation while task automaticity increases. Copyright © 2015 Elsevier Inc. All rights reserved.

CHARACTERISTICS OF A 4-PHASE VALVE RELUCTANCE MOTOR WHEN POWERED BY UNCAPACITOR SWITCHBOARD

Directory of Open Access Journals (Sweden)

V.B. Finkelshtein

2016-06-01

Full Text Available Purpose. Nowadays more and more in a variety of machines and mechanisms applied switched reluctance motor. When designing these engines solve the problem selection switch. While the switch scheme comprises symmetrical bridge and eight transistors, eight diodes; Miller switch comprises six transistors and six diodes; in company Graseby Controls Ltd switch circuit but four transistors and four diodes includes two capacitors. The aim is to develop a mathematical model, calculation program, a numerical analysis of the characteristics and parameters of the WFD and the characteristics of their work. Methodology. It is assumed that the resistance in the open state transistors and diodes for direct current is zero and the resistance of the transistors in the closed state, and diode reverse voltage is infinity. When feeding a single-phase motor and power at the same time two adjacent phases determined by the flow through the tooth. Results. The motor powered by a switch on the circuit symmetrical bridge power, which provides a maximum permissible winding temperature is 1.665 kW. But at the same time the surge up to 38.8%, resulting in high levels of noise and vibration. Through the installation of switching angles, ensuring reduction of torque ripple and reduce engine power to a level below which there is a decrease in the value of torque ripple, received power of 1,066 kW and a torque ripple value of 21.18 %. For engines with improved vibration acoustic characteristics necessary to use a switch of four transistors and four diodes. Practical value. For motors with improved vibration acoustic characteristics appropriate to apply uncapacitor switch on four transistors and four diodes, which allows you to receive half the value of torque ripple than the lowest value of the motor torque ripple, eating from a switch on the circuit asymmetric bridge. The cost of reluctance motor with uncapacitor switch on the circuit with four transistors and four diodes is

Interference in Ballistic Motor Learning: Specificity and Role of Sensory Error Signals

Science.gov (United States)

Lundbye-Jensen, Jesper; Petersen, Tue Hvass; Rothwell, John C.; Nielsen, Jens Bo

2011-01-01

Humans are capable of learning numerous motor skills, but newly acquired skills may be abolished by subsequent learning. Here we ask what factors determine whether interference occurs in motor learning. We speculated that interference requires competing processes of synaptic plasticity in overlapping circuits and predicted specificity. To test this, subjects learned a ballistic motor task. Interference was observed following subsequent learning of an accuracy-tracking task, but only if the competing task involved the same muscles and movement direction. Interference was not observed from a non-learning task suggesting that interference requires competing learning. Subsequent learning of the competing task 4 h after initial learning did not cause interference suggesting disruption of early motor memory consolidation as one possible mechanism underlying interference. Repeated transcranial magnetic stimulation (rTMS) of corticospinal motor output at intensities below movement threshold did not cause interference, whereas suprathreshold rTMS evoking motor responses and (re)afferent activation did. Finally, the experiments revealed that suprathreshold repetitive electrical stimulation of the agonist (but not antagonist) peripheral nerve caused interference. The present study is, to our knowledge, the first to demonstrate that peripheral nerve stimulation may cause interference. The finding underscores the importance of sensory feedback as error signals in motor learning. We conclude that interference requires competing plasticity in overlapping circuits. Interference is remarkably specific for circuits involved in a specific movement and it may relate to sensory error signals. PMID:21408054

Perspectives on Early Power Mobility Training, Motivation, and Social Participation in Young Children with Motor Disabilities

Directory of Open Access Journals (Sweden)

Hsiang-Han Huang

2018-01-01

Full Text Available The efficacy of traditional training programs (e.g., neurodevelopmental therapy in promoting independent mobility and early child development across all three International Classification of Functioning, Disability, and Health levels lacks rigorous research support. Therefore, early power mobility training needs to be considered as a feasible intervention for very young children who are unlikely to achieve independent mobility. This perspective article has three aims: (1 to provide empirical evidence of differences in early independent mobility, motivation, daily life activities, and social participation between young children with typical development and motor disabilities; (2 to discuss the contemporary concepts of and approaches to early power mobility training for young children with motor disabilities and the current need for changes to such training; and (3 to provide recommendations for early power mobility training in pediatric rehabilitation. Independent mobility is critical for social participation; therefore, power mobility can be accessible and implemented as early as possible, specifically for infants who are at risk for mobility or developmental delay. To maximize the positive effects of independent mobility on children’s social participation, early power mobility training must consider their levels of functioning, the amount of exploration and contextual factors, including individual and environmental factors.

Comparison of the fractional power motor with cores made of various magnetic materials

Directory of Open Access Journals (Sweden)

Gmyrek Zbigniew

2017-12-01

Full Text Available The optimization of the motor cores, coupled with new core shapes as well as powering the motor at high frequency are the primary reasons for the use of new materials. The utilization of new materials, like SMC (soft magnetic composite, reduce the core loss and/or provide quasi-isotropic core’s properties in any magnetization direction. Moreover, the use of SMC materials allows for avoiding degradation of the material portions, resulting from punching process, thereby preventing the deterioration of operating parameters of the motor. The authors examine the impact of technological parameters on the properties of a new type of SMC material and analyze the possibility of its use as the core of the fractional power motor. The result of the work is an indication of the shape of the rotor core made of a new SMC material to achieve operational parameters similar to those that have a motor with a core made of laminations.

Comparison of the fractional power motor with cores made of various magnetic materials

Science.gov (United States)

Gmyrek, Zbigniew; Lefik, Marcin; Cavagnino, Andrea; Ferraris, Luca

2017-12-01

The optimization of the motor cores, coupled with new core shapes as well as powering the motor at high frequency are the primary reasons for the use of new materials. The utilization of new materials, like SMC (soft magnetic composite), reduce the core loss and/or provide quasi-isotropic core's properties in any magnetization direction. Moreover, the use of SMC materials allows for avoiding degradation of the material portions, resulting from punching process, thereby preventing the deterioration of operating parameters of the motor. The authors examine the impact of technological parameters on the properties of a new type of SMC material and analyze the possibility of its use as the core of the fractional power motor. The result of the work is an indication of the shape of the rotor core made of a new SMC material to achieve operational parameters similar to those that have a motor with a core made of laminations.

FEATURES OF ELECTRIC MOTOR CHOICE FOR NUCLEAR POWER PLANT TECHNOLOGICAL OBJECTS

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V.V. Shevchenko

2013-06-01

Full Text Available Nuclear power plants remain the basic power generating enterprises for Ukraine. Execution of works on their reliability control and operating conditions optimization is therefore of current importance. Trouble-free nuclear power plant operation is a vital technical, economical, and ecological problem, a solution to which is largely specified by reliable operation of electric equipment, namely, electric motors of nuclear power plant technological process drives.

Assessment of load of beam-balanced pumping units by electric motor power indicators

Directory of Open Access Journals (Sweden)

Д. И. Шишлянников

2017-10-01

Full Text Available The results of experimental studies on the loading of beam-balanced pumping units (BP of sucker rod- pumping equipment (SRPE are presented. It is noted that the key factor that has the most significant effect causing the SRPE failure is the balance of the beam pumping unit, which determines the amount of specific energy consumption for the rise of reservoir fluid and the level of dynamic loads on the machine units. The urgency of using software-recording systems for estimating the loading of units of oil field pumping installations is substantiated. The principle of operation and design of the «AKD-SK» software recording system is described. The prospects of using this method for controlling the performance parameters and evaluating the technical state of the sicker rod-pumping units is proved on the basis of an analysis of the magnitude and nature of the changes in the loads of drive motors determined by the registration of the instantaneous values of the consumed power. The main provisions of the methodology for analyzing the watt-meters of drive motors of the sucker rod-pumping units are outlined. The nature of the manifestation of the main defects of submersible pumps and beam-balanced pumping units is described. The results of pilot-industrial tests of the beam-balanced pumping units equipped with advanced permanent magnet motors and intelligent control stations are presented. It is proved that the use of permanent magnet motors allows to reduce the specific energy consumption for the rise of reservoir fluid, which increases the efficiency of the SRPE.However, the presence of transient processes and generator operating modes of the permanent magnet motors results in the occurrence of significant dynamic loads, which, due to the rigid fixing of the rotor of magnet motor on the reducer shaft, negatively affect the life of the gearbox bearings. It has been shown that the lack of its own bearings in the tested motors causes a high probability

76 FR 45741 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Diesel-Powered Motor...

Science.gov (United States)

2011-08-01

... Promulgation of Air Quality Implementation Plans; Pennsylvania; Diesel-Powered Motor Vehicle Idling Act AGENCY... the Commonwealth's Diesel-Powered Motor Vehicle Idling Act (Act 124 of 2008, or simply Act 124) into... allowable time that heavy-duty, commercial highway diesel vehicles of over 10,000 pounds gross vehicle...

Age-related changes in oscillatory power affect motor action.

Directory of Open Access Journals (Sweden)

Liqing Liu

Full Text Available With increasing age cognitive performance slows down. This includes cognitive processes essential for motor performance. Additionally, performance of motor tasks becomes less accurate. The objective of the present study was to identify general neural correlates underlying age-related behavioral slowing and the reduction in motor task accuracy. To this end, we continuously recorded EEG activity from 18 younger and 24 older right-handed healthy participants while they were performing a simple finger tapping task. We analyzed the EEG records with respect to local changes in amplitude (power spectrum as well as phase locking between the two age groups. We found differences between younger and older subjects in the amplitude of post-movement synchronization in the β band of the sensory-motor and medial prefrontal cortex (mPFC. This post-movement β amplitude was significantly reduced in older subjects. Moreover, it positively correlated with the accuracy with which subjects performed the motor task at the electrode FCz, which detects activity of the mPFC and the supplementary motor area. In contrast, we found no correlation between the accurate timing of local neural activity, i.e. phase locking in the δ-θ frequency band, with the reaction and movement time or the accuracy with which the motor task was performed. Our results show that only post-movement β amplitude and not δ-θ phase locking is involved in the control of movement accuracy. The decreased post-movement β amplitude in the mPFC of older subjects hints at an impaired deactivation of this area, which may affect the cognitive control of stimulus-induced motor tasks and thereby motor output.

How thoughts give rise to action - conscious motor intention increases the excitability of target-specific motor circuits.

Directory of Open Access Journals (Sweden)

Volker R Zschorlich

Full Text Available The present study shows evidence for conscious motor intention in motor preparation prior to movement execution. We demonstrate that conscious motor intention of directed movement, combined with minimally supra-threshold transcranial magnetic stimulation (TMS of the motor cortex, determines the direction and the force of resulting movements, whilst a lack of intention results in weak and omni-directed muscle activation. We investigated changes of consciously intended goal directed movements by analyzing amplitudes of motor-evoked potentials of the forearm muscle, flexor carpi radialis (FCR, and extensor carpi radialis (ECR, induced by transcranial magnetic stimulation over the right motor cortex and their motor outcome. Right-handed subjects were asked to develop a strong intention to move their left wrist (flexion or extension, without any overt motor output at the wrist, prior to brain stimulation. Our analyses of hand acceleration and electromyography showed that during the strong motor intention of wrist flexion movement, it evoked motor potential responses that were significantly larger in the FCR muscle than in the ECR, whilst the opposite was true for an extension movement. The acceleration data on flexion/extension corresponded to this finding. Under no-intention conditions again, which served as a reference for motor evoked potentials, brain stimulation resulted in undirected and minimally simultaneous extension/flexion innervation and virtually no movement. These results indicate that conscious intentions govern motor function, which in turn shows that a neuronal activation representing an "intention network" in the human brain pre-exists, and that it functionally represents target specific motor circuits. Until today, it was unclear whether conscious motor intention exists prior to movement, or whether the brain constructs such an intention after movement initiation. Our study gives evidence that motor intentions become aware before

How Thoughts Give Rise to Action - Conscious Motor Intention Increases the Excitability of Target-Specific Motor Circuits

Science.gov (United States)

Zschorlich, Volker R.; Köhling, Rüdiger

2013-01-01

The present study shows evidence for conscious motor intention in motor preparation prior to movement execution. We demonstrate that conscious motor intention of directed movement, combined with minimally supra-threshold transcranial magnetic stimulation (TMS) of the motor cortex, determines the direction and the force of resulting movements, whilst a lack of intention results in weak and omni-directed muscle activation. We investigated changes of consciously intended goal directed movements by analyzing amplitudes of motor-evoked potentials of the forearm muscle, flexor carpi radialis (FCR), and extensor carpi radialis (ECR), induced by transcranial magnetic stimulation over the right motor cortex and their motor outcome. Right-handed subjects were asked to develop a strong intention to move their left wrist (flexion or extension), without any overt motor output at the wrist, prior to brain stimulation. Our analyses of hand acceleration and electromyography showed that during the strong motor intention of wrist flexion movement, it evoked motor potential responses that were significantly larger in the FCR muscle than in the ECR, whilst the opposite was true for an extension movement. The acceleration data on flexion/extension corresponded to this finding. Under no-intention conditions again, which served as a reference for motor evoked potentials, brain stimulation resulted in undirected and minimally simultaneous extension/flexion innervation and virtually no movement. These results indicate that conscious intentions govern motor function, which in turn shows that a neuronal activation representing an “intention network” in the human brain pre-exists, and that it functionally represents target specific motor circuits. Until today, it was unclear whether conscious motor intention exists prior to movement, or whether the brain constructs such an intention after movement initiation. Our study gives evidence that motor intentions become aware before any motor

Development of an integrated condition monitoring and diagnostic system for motor-operated valves used in nuclear power plant

International Nuclear Information System (INIS)

Carneiro, Alvaro Luiz Guimaraes

2003-01-01

The reliability question of the components, specifically of motor operated valves, became one of the most important issues to be investigated in nuclear power plants, considering security and life plant extension. Therefore, the necessity of improvements in monitoring and diagnosis methods started to be of extreme relevance in the maintenance predictive field, establishing as main goal the reliability and readiness of the system components. Specially in nuclear power plants, the predictive maintenance contributes in the security factor in order to diagnosis in advance the occurrence of a possible failure, preventing severe situations. It also presents a contribution on the economic side by establishing a better maintenance programming, and reducing unexpected shutdown. The development of non intrusive monitoring and diagnostic method makes it possible to identify malfunctions in plant components during normal plant operation. This dissertation presents the development of an integrated condition monitoring system for motor-operated valves used in nuclear power plants. The methodology used in this project is based on the electric motor power signatures analysis, during the closing and opening stroke time of the valve. Once the measurements baseline diagnostic of the motor-operated valve is taken, it is possible to detect long-term deviations during valve lifetime, detecting in advance valve failures. The system implements two parallel techniques for detection and categorization of anomalies: expert system using fuzzy logic based on rules and knowledge base, providing a systematic approach for decision making, and the Wavelet Transform Technique, where the main goal is to obtain more detailed information contained in the measured data, identifying and characterizing the transients phenomena in the time and frequency domains, correlating them to failures situations in the incipient stage. The conditioning monitoring and diagnostic system was designed and implemented at

A Study on the Development of BLDC Motor with High Power Density

Energy Technology Data Exchange (ETDEWEB)

Kim, Hyun Cheol; Kong, Yeong Kyung; Choi, Tae In [Agency for Defense Development (Korea); Song, Jong Hwan [Hyosung Ltd., (Korea)

2000-05-01

The motor for torpedo propulsion is needed the compact and short rating high power characteristics. This paper describes the development of the motor through the theory and Finite Element Method(FEM) analysis for Brushless Direct Current Motor(BLDCM) of 7 phase 6 poles. Back EMF, inductance and eddy current loss were analyzed. The proposed methods like magnetic wedge acquired by these FEM analysis were introduced. Phase-leading angle using encoder was used. Test results on the motor of 7 phases 6 poles were showed the validity of proposed methods and phase-leading angle. (author). 9 refs., 12 figs., 5 tabs.

Analysis and Design Considerations of a High-Power Density, Dual Air Gap, Axial-Field Brushless, Permanent Magnet Motor.

Science.gov (United States)

Cho, Chahee Peter

1995-01-01

Until recently, brush dc motors have been the dominant drive system because they provide easily controlled motor speed over a wide range, rapid acceleration and deceleration, convenient control of position, and lower product cost. Despite these capabilities, the brush dc motor configuration does not satisfy the design requirements for the U.S. Navy's underwater propulsion applications. Technical advances in rare-earth permanent magnet materials, in high-power semiconductor transistor technology, and in various rotor position-sensing devices have made using brushless permanent magnet motors a viable alternative. This research investigates brushless permanent magnet motor technology, studying the merits of dual-air gap, axial -field, brushless, permanent magnet motor configuration in terms of power density, efficiency, and noise/vibration levels. Because the design objectives for underwater motor applications include high-power density, high-performance, and low-noise/vibration, the traditional, simplified equivalent circuit analysis methods to assist in meeting these goals were inadequate. This study presents the development and verification of detailed finite element analysis (FEA) models and lumped parameter circuit models that can calculate back electromotive force waveforms, inductance, cogging torque, energized torque, and eddy current power losses. It is the first thorough quantification of dual air-gap, axial -field, brushless, permanent magnet motor parameters and performance characteristics. The new methodology introduced in this research not only facilitates the design process of an axial field, brushless, permanent magnet motor but reinforces the idea that the high-power density, high-efficiency, and low-noise/vibration motor is attainable.

Region and task-specific activation of Arc in primary motor cortex of rats following motor skill learning.

Science.gov (United States)

Hosp, J A; Mann, S; Wegenast-Braun, B M; Calhoun, M E; Luft, A R

2013-10-10

Motor learning requires protein synthesis within the primary motor cortex (M1). Here, we show that the immediate early gene Arc/Arg3.1 is specifically induced in M1 by learning a motor skill. Arc mRNA was quantified using a fluorescent in situ hybridization assay in adult Long-Evans rats learning a skilled reaching task (SRT), in rats performing reaching-like forelimb movement without learning (ACT) and in rats that were trained in the operant but not the motor elements of the task (controls). Apart from M1, Arc expression was assessed within the rostral motor area (RMA), primary somatosensory cortex (S1), striatum (ST) and cerebellum. In SRT animals, Arc mRNA levels in M1 contralateral to the trained limb were 31% higher than ipsilateral (pmotor skill learning in rats. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.

CHOOSING THE POWER OF TRACTION ELECTRIC MOTORS FOR ELECTRIC VEHICLES

OpenAIRE

O. Smirnov; A. Borisenko

2017-01-01

Recommendations on choosing the power of the electric motor, depending on the weight of the vehicle, its speed and the run distance in the «only electricity» mode are developed. Based on mathematical modeling and a number of field tests of electric vehicles, a three-dimensional dependance of the power on the weight and the speed set is built and conclusions are presented.

CHOOSING THE POWER OF TRACTION ELECTRIC MOTORS FOR ELECTRIC VEHICLES

Directory of Open Access Journals (Sweden)

O. Smirnov

2017-06-01

Full Text Available Recommendations on choosing the power of the electric motor, depending on the weight of the vehicle, its speed and the run distance in the «only electricity» mode are developed. Based on mathematical modeling and a number of field tests of electric vehicles, a three-dimensional dependance of the power on the weight and the speed set is built and conclusions are presented.

Lightweight High Efficiency Electric Motors for Space Applications

Science.gov (United States)

Robertson, Glen A.; Tyler, Tony R.; Piper, P. J.

2011-01-01

Lightweight high efficiency electric motors are needed across a wide range of space applications from - thrust vector actuator control for launch and flight applications to - general vehicle, base camp habitat and experiment control for various mechanisms to - robotics for various stationary and mobile space exploration missions. QM Power?s Parallel Path Magnetic Technology Motors have slowly proven themselves to be a leading motor technology in this area; winning a NASA Phase II for "Lightweight High Efficiency Electric Motors and Actuators for Low Temperature Mobility and Robotics Applications" a US Army Phase II SBIR for "Improved Robot Actuator Motors for Medical Applications", an NSF Phase II SBIR for "Novel Low-Cost Electric Motors for Variable Speed Applications" and a DOE SBIR Phase I for "High Efficiency Commercial Refrigeration Motors" Parallel Path Magnetic Technology obtains the benefits of using permanent magnets while minimizing the historical trade-offs/limitations found in conventional permanent magnet designs. The resulting devices are smaller, lower weight, lower cost and have higher efficiency than competitive permanent magnet and non-permanent magnet designs. QM Power?s motors have been extensively tested and successfully validated by multiple commercial and aerospace customers and partners as Boeing Research and Technology. Prototypes have been made between 0.1 and 10 HP. They are also in the process of scaling motors to over 100kW with their development partners. In this paper, Parallel Path Magnetic Technology Motors will be discussed; specifically addressing their higher efficiency, higher power density, lighter weight, smaller physical size, higher low end torque, wider power zone, cooler temperatures, and greater reliability with lower cost and significant environment benefit for the same peak output power compared to typically motors. A further discussion on the inherent redundancy of these motors for space applications will be provided.

Determination of the needed power of an electric motor on the basis of acceleration time of the electric car

Science.gov (United States)

Sapundzhiev, M.; Evtimov, I.; Ivanov, R.

2017-10-01

The paper presents an upgraded methodology for determination of the electric motor power considering the time for acceleration. The influence of the speed factor of electric motor on the value of needed power at same acceleration time is studied. Some calculations on the basis of real vehicle were made. The numeric and graphical results are given. They show a decrease of needed power with the increase of the speed factor of motor, because the high speed factor allows the use of a larger range of the characteristic with the maximum power of the motor. An experimental verification of methodology was done.

Frequency modulation drive for a piezoelectric motor

Science.gov (United States)

Mittas, Anthony

2001-01-01

A piezoelectric motor has peak performance at a specific frequency f.sub.1 that may vary over a range of frequencies. A drive system is disclosed for operating such a motor at peak performance without feedback. The drive system consists of the motor and an ac source connected to power the motor, the ac source repeatedly generating a frequency over a range from f.sub.1 -.DELTA.x to f.sub.1 +.DELTA.y.

Modelling and Design of Active Thermal Controls for Power Electronics of Motor Drive Applications

DEFF Research Database (Denmark)

Vernica, Ionut; Blaabjerg, Frede; Ma, Ke

2017-01-01

of active thermal control methods for the power devices of a motor drive application. The motor drive system together with the thermal cycling of the power devices have been modelled, and adverse temperature swings could be noticed during the start-up and deceleration periods of the motor. Based...... on the electrical response of the system, the junction temperature of the semiconductor devices is estimated, and consequently three active thermal control methods are proposed and practically designed with respect to the following parameters: switching frequency, deceleration slope and modulation technique....... Finally, experimental results are provided in order to validate the effectiveness of the proposed control methods....

Recapitulation of spinal motor neuron-specific disease phenotypes in a human cell model of spinal muscular atrophy

Institute of Scientific and Technical Information of China (English)

Zhi-Bo Wang; Xiaoqing Zhang; Xue-Jun Li

2013-01-01

Establishing human cell models of spinal muscular atrophy (SMA) to mimic motor neuron-specific phenotypes holds the key to understanding the pathogenesis of this devastating disease.Here,we developed a closely representative cell model of SMA by knocking down the disease-determining gene,survival motor neuron (SMN),in human embryonic stem cells (hESCs).Our study with this cell model demonstrated that knocking down of SMN does not interfere with neural induction or the initial specification of spinal motor neurons.Notably,the axonal outgrowth of spinal motor neurons was significantly impaired and these disease-mimicking neurons subsequently degenerated.Furthermore,these disease phenotypes were caused by SMN-full length (SMN-FL) but not SMN-A7 (lacking exon 7)knockdown,and were specific to spinal motor neurons.Restoring the expression of SMN-FL completely ameliorated all of the disease phenotypes,including specific axonal defects and motor neuron loss.Finally,knockdown of SMNFL led to excessive mitochondrial oxidative stress in human motor neuron progenitors.The involvement of oxidative stress in the degeneration of spinal motor neurons in the SMA cell model was further confirmed by the administration of N-acetylcysteine,a potent antioxidant,which prevented disease-related apoptosis and subsequent motor neuron death.Thus,we report here the successful establishment of an hESC-based SMA model,which exhibits disease gene isoform specificity,cell type specificity,and phenotype reversibility.Our model provides a unique paradigm for studying how motor neurons specifically degenerate and highlights the potential importance of antioxidants for the treatment of SMA.

The Specificity of Action Knowledge in Sensory and Motor Systems

Directory of Open Access Journals (Sweden)

Christine E Watson

2014-05-01

Full Text Available Neuroimaging studies have found that sensorimotor systems are engaged when participants observe actions or comprehend action language. However, most of these studies have asked the binary question of whether action concepts are embodied or not, rather than whether sensory and motor areas of the brain contain graded amounts of information during putative action simulations. To address this question, we used repetition suppression (RS functional magnetic resonance imaging to determine if functionally-localized motor movement and visual motion regions-of-interest (ROI and two anatomical ROIs (inferior frontal gyrus, IFG; left posterior middle temporal gyrus were sensitive to changes in the exemplar (e.g., two different people kicking or representational format (e.g., photograph or schematic drawing of someone kicking within pairs of action images. We also investigated whether concrete versus more symbolic depictions of actions (i.e., photographs versus schematic drawings yielded different patterns of activation throughout the brain. We found that during a conceptual task, sensory and motor systems represent actions at different levels of specificity. While the visual motion ROI did not exhibit RS to different exemplars of the same action or to the same action depicted by different formats, the motor movement ROI did. These effects are consistent with person-specific action simulations: if the motor system is recruited for action understanding, it does so by activating one’s own motor program for an action. We also observed significant repetition enhancement within the IFG ROI to different exemplars or formats of the same action, a result that may indicate additional cognitive processing on these trials. Finally, we found that the recruitment of posterior brain regions by action concepts depends on the format of the input: left lateral occipital cortex and right supramarginal gyrus responded more strongly to symbolic depictions of actions than

Armature reaction of permanent magnet-excited small dc motors with shell type magnets and possibilities of power increase

Energy Technology Data Exchange (ETDEWEB)

Gutt, H J; Tran, Q N

1983-07-01

Permanent magnet-excited small dc motors allow an increase of power up to 30% compared with present permanent excited motors. The calculation of immediate irreversible demagnetization of the air-gap situated shell type magnets is necessary for a good motor design. Numerical calculated field line plots show the critical zones of the irreversible demagnetization at high armature reaction and refer how to avoid the flux loss and to increase the motor power.

Aging Management Guideline for commercial nuclear power plants: Motor control centers

International Nuclear Information System (INIS)

Toman, G.; Gazdzinski, R.; O'Hearn, E.

1994-02-01

This Aging Management Guideline (AMG) provides recommended methods for effective detection and mitigation of age-related degradation mechanisms in Boiling Water Reactor (BWR) and Pressurized Water Reactor (PWR) commercial nuclear power plant motor control centers important to license renewal. The intent of this AMG is to assist plant maintenance and operations personnel in maximizing the safe, useful life of these components. It also supports the documentation of effective aging management programs required under the License Renewal Rule 10 CFR Part 54. This AMG is presented in a manner that allows personnel responsible for performance analysis and maintenance to compare their plant-specific aging mechanisms (expected or already experienced) and aging management program activities to the more generic results and recommendations presented herein

Direct and Conceptual Replications of Burgmer & Englich (2012: Power May Have Little to No Effect on Motor Performance.

Directory of Open Access Journals (Sweden)

Margaret Cusack

Full Text Available Burgmer and Englich (2012 have reported that manipulating feelings of power can substantially improve performance on two motor tasks: golf and darts. We conducted two high-powered direct replications of the effects of power on golf, two online conceptual replications using mirror-tracing as a performance measure, and an additional conceptual replication using a cognitive performance measure (word-search. Overall, we found little to no effect of power on motor skill (d = 0.09, 95% CI[-0.07, 0.22], n = 603. We varied task difficulty, re-analyzed data without participants showing weak responses on manipulation checks, and tried adjusting performance scores for age, gender, and initial task skill. None of these secondary analyses revealed a strong effect of power on performance. A meta-analysis integrating our data with Burgmer & Englich leaves open the possibility that manipulating power could provide a modest boost in motor skill (d = 0.19, 95% CI [0.001, 0.38], n = 685. Unfortunately, the pattern of performance changes we observed was unrelated to group differences in perceived and rated power, suggesting that what motor effects do occur with this protocol may not be directly related to the construct of power. [Burgmer, P., &Englich, B. (2012. Bullseye!: How Power Improves Motor Performance. Social Psychological and Personality Science, 4(2, 224-232.].

Generalized Motor Abilities and Timing Behavior in Children with Specific Language Impairment

Science.gov (United States)

Zelaznik, Howard N.; Goffman, Lisa

2010-01-01

Purpose: To examine whether children with specific language impairment (SLI) differ from normally developing peers in motor skills, especially those skills related to timing. Method: Standard measures of gross and fine motor development were obtained. Furthermore, finger and hand movements were recorded while children engaged in 4 different timing…

Advanced Ultra-High Speed Motor for Drilling

Energy Technology Data Exchange (ETDEWEB)

Impact Technologies LLC; University of Texas at Arlington

2007-03-31

Three (3) designs have been made for two sizes, 6.91 cm (2.72 inch) and 4.29 cm (1.69 inch) outer diameters, of a patented inverted configured Permanent Magnet Synchronous Machines (PMSM) electric motor specifically for drilling at ultra-high rotational speeds (10,000 rpm) and that can utilize advanced drilling methods. Benefits of these motors are stackable power sections, full control (speed and direction) of downhole motors, flow hydraulics independent of motor operation, application of advanced drilling methods (water jetting and abrasive slurry jetting), and the ability of signal/power electric wires through motor(s). Key features of the final designed motors are: fixed non-rotating shaft with stator coils attached; rotating housing with permanent magnet (PM) rotor attached; bit attached to rotating housing; internal channel(s) in a nonrotating shaft; electric components that are hydrostatically isolated from high internal pressure circulating fluids ('muds') by static metal to metal seals; liquid filled motor with smoothed features for minimized turbulence in the motor during operation; and new inverted coated metal-metal hydrodynamic bearings and seals. PMSM, Induction and Switched Reluctance Machines (SRM), all pulse modulated, were considered, but PMSM were determined to provide the highest power density for the shortest motors. Both radial and axial electric PMSM driven motors were designed with axial designs deemed more rugged for ultra-high speed, drilling applications. The 6.91 cm (2.72 inch) OD axial inverted motor can generate 4.18KW (5.61 Hp) power at 10,000 rpm with a 4 Nm (2.95 ft-lbs) of torque for every 30.48 cm (12 inches) of power section. The 6.91 cm (2.72 inch) OD radial inverted motor can generate 5.03 KW (6.74 Hp) with 4.8 Nm (3.54 ft-lb) torque at 10,000 rpm for every 30.48 cm (12 inches) of power section. The 4.29 cm (1.69 inch) OD radial inverted motor can generate 2.56 KW (3.43 Hp) power with 2.44 Nm (1.8 ft-lb) torque at

Non-stationarity and power spectral shifts in EMG activity reflect motor unit recruitment in rat diaphragm muscle.

Science.gov (United States)

Seven, Yasin B; Mantilla, Carlos B; Zhan, Wen-Zhi; Sieck, Gary C

2013-01-15

We hypothesized that a shift in diaphragm muscle (DIAm) EMG power spectral density (PSD) to higher frequencies reflects recruitment of more fatigable fast-twitch motor units and motor unit recruitment is reflected by EMG non-stationarity. DIAm EMG was recorded in anesthetized rats during eupnea, hypoxia-hypercapnia (10% O(2)-5% CO(2)), airway occlusion, and sneezing (maximal DIAm force). Although power in all frequency bands increased progressively across motor behaviors, PSD centroid frequency increased only during sneezing (pmotor units were recruited during different motor behaviors. Motor units augmented their discharge frequencies progressively beyond the non-stationary period; yet, EMG signal became stationary. In conclusion, non-stationarity of DIAm EMG reflects the period of motor unit recruitment, while a shift in the PSD towards higher frequencies reflects recruitment of more fatigable fast-twitch motor units. Copyright © 2012 Elsevier B.V. All rights reserved.

Power-optimal force decoupling in a hybrid linear reluctance motor

NARCIS (Netherlands)

Overboom, T.T.; Smeets, J.P.C.; Jansen, J.W.; Lomonova, E.A.; Mavrudieva, D.

2015-01-01

This paper concerns the power-optimal decoupling of the propulsion and normal force created by a hybrid linear reluctance motor. The intrinsic limitations to the decoupling is addressed by the visualizing each force component with a quadric surface in the Euclidean space which is spanned by the

Symptom-specific amygdala hyperactivity modulates motor control network in conversion disorder

Directory of Open Access Journals (Sweden)

Thomas Hassa

2017-01-01

Full Text Available Initial historical accounts as well as recent data suggest that emotion processing is dysfunctional in conversion disorder patients and that this alteration may be the pathomechanistic neurocognitive basis for symptoms in conversion disorder. However, to date evidence of direct interaction of altered negative emotion processing with motor control networks in conversion disorder is still lacking. To specifically study the neural correlates of emotion processing interacting with motor networks we used a task combining emotional and sensorimotor stimuli both separately as well as simultaneously during functional magnetic resonance imaging in a well characterized group of 13 conversion disorder patients with functional hemiparesis and 19 demographically matched healthy controls. We performed voxelwise statistical parametrical mapping for a priori regions of interest within emotion processing and motor control networks. Psychophysiological interaction (PPI was used to test altered functional connectivity of emotion and motor control networks. Only during simultaneous emotional stimulation and passive movement of the affected hand patients displayed left amygdala hyperactivity. PPI revealed increased functional connectivity in patients between the left amygdala and the (pre-supplemental motor area and the subthalamic nucleus, key regions within the motor control network. These findings suggest a novel mechanistic direct link between dysregulated emotion processing and motor control circuitry in conversion disorder.

Symptom-specific amygdala hyperactivity modulates motor control network in conversion disorder.

Science.gov (United States)

Hassa, Thomas; Sebastian, Alexandra; Liepert, Joachim; Weiller, Cornelius; Schmidt, Roger; Tüscher, Oliver

2017-01-01

Initial historical accounts as well as recent data suggest that emotion processing is dysfunctional in conversion disorder patients and that this alteration may be the pathomechanistic neurocognitive basis for symptoms in conversion disorder. However, to date evidence of direct interaction of altered negative emotion processing with motor control networks in conversion disorder is still lacking. To specifically study the neural correlates of emotion processing interacting with motor networks we used a task combining emotional and sensorimotor stimuli both separately as well as simultaneously during functional magnetic resonance imaging in a well characterized group of 13 conversion disorder patients with functional hemiparesis and 19 demographically matched healthy controls. We performed voxelwise statistical parametrical mapping for a priori regions of interest within emotion processing and motor control networks. Psychophysiological interaction (PPI) was used to test altered functional connectivity of emotion and motor control networks. Only during simultaneous emotional stimulation and passive movement of the affected hand patients displayed left amygdala hyperactivity. PPI revealed increased functional connectivity in patients between the left amygdala and the (pre-)supplemental motor area and the subthalamic nucleus, key regions within the motor control network. These findings suggest a novel mechanistic direct link between dysregulated emotion processing and motor control circuitry in conversion disorder.

Application of high temperature superconductivity to electric motor design

International Nuclear Information System (INIS)

Edmonds, J.S.; Sharma, D.K.; Jordan, H.E.; Edick, J.D.; Schiferl, R.F.

1992-01-01

This paper reports on progress made in a joint project conducted by the Electric Power Research Institute and Reliance Electric Company to study the possible application of High Temperature Super Conductors (HTSC), materials to electric motors. Specific applications are identified which can be beneficially served by motors constructed with HTSC materials. A summary is presented of the components and design issues related to HTSC motors designed for these applications. During the course of this development program, a three tier HTSC wire performance specification has evolved. The three specifications and the rationale behind these three levels of performance are explained. A description of a test motor that has been constructed to verify the electromagnetic analytical techniques of HTSC motor design is given. Finally, a DC motor with an HTSC field coil is described. Measured data with the motor running is presented showing that the motor is operating with the field winding in the superconducting state

Motormouth: Mere Exposure Depends on Stimulus-Specific Motor Simulations

Science.gov (United States)

Topolinski, Sascha; Strack, Fritz

2009-01-01

The authors apply an embodied account to mere exposure, arguing that through the repeated exposure of a particular stimulus, motor responses specifically associated to that stimulus are repeatedly simulated, thus trained, and become increasingly fluent. This increased fluency drives preferences for repeated stimuli. This hypothesis was tested by…

Motor life management at Gentilly 2 nuclear power plant

International Nuclear Information System (INIS)

Lazic, L.; Renaud, P.; Marcotte, P.

2002-01-01

Hydro Quebec's Gentilly 2 CANDU Nuclear Power Plant (NPP) located on the St. Lawrence River about 150 kms NE of Montreal Quebec Canada, is completing its second full decade of commercial operation. Since the original design life of 30 years is fast approaching, Hydro Quebec (HQ) is positioning itself proactively, to ensure plant operation for the original design life as well implementing a plant life management program to achieve a plant life extension to 50 years. All components in a nuclear plant are affected by ageing during the plant service life. This affects the availability, reliability, and safety of the plant operation and could affect the plant service life. However, if a life management program (LMP) is implemented; the ageing mechanisms can be understood and monitored, and their effects can be controlled and even mitigated. Among other vital equipment in the plant, the station motors are being examined to determine what has to be done to ensure that the motors do not contribute negatively to the plant operating plan. Gentilly 2 NPP has almost 900 motors of various configurations. Their size ranges from 0.1 HP to 9000 HP. A distribution of quantity at different horsepower levels is given. This paper will describe the plant's motor history, method of operation, and proposed future changes required to ensure effective life management of the motors. Up to the present time, Gentilly 2 NPP staff has had very good experience with plant motor operation and reliability. Nevertheless, indications from other industry motor experiences indicate that this favourable trend is unlikely to continue. A plant motor life management strategy as outlined in this paper, based on condition based maintenance in combination with traditional types of maintenance, can help to ensure protection against unexpected plant motor problems and help to ensure achievement of motor design life and beyond. Although nothing will ever replace a thorough visual inspection for discovering

Interference in ballistic motor learning: specificity and role of sensory error signals

DEFF Research Database (Denmark)

Lundbye-Jensen, Jesper; Petersen, Tue Hvass; Rothwell, John C

2011-01-01

Humans are capable of learning numerous motor skills, but newly acquired skills may be abolished by subsequent learning. Here we ask what factors determine whether interference occurs in motor learning. We speculated that interference requires competing processes of synaptic plasticity in overlap......Humans are capable of learning numerous motor skills, but newly acquired skills may be abolished by subsequent learning. Here we ask what factors determine whether interference occurs in motor learning. We speculated that interference requires competing processes of synaptic plasticity...... in overlapping circuits and predicted specificity. To test this, subjects learned a ballistic motor task. Interference was observed following subsequent learning of an accuracy-tracking task, but only if the competing task involved the same muscles and movement direction. Interference was not observed from a non......-learning task suggesting that interference requires competing learning. Subsequent learning of the competing task 4 h after initial learning did not cause interference suggesting disruption of early motor memory consolidation as one possible mechanism underlying interference. Repeated transcranial magnetic...

Body-part specific interactions of action verb processing with motor behaviour.

Science.gov (United States)

Klepp, Anne; Niccolai, Valentina; Sieksmeyer, Jan; Arnzen, Stephanie; Indefrey, Peter; Schnitzler, Alfons; Biermann-Ruben, Katja

2017-06-15

The interaction of action-related language processing with actual movement is an indicator of the functional role of motor cortical involvement in language understanding. This paper describes two experiments using single action verb stimuli. Motor responses were performed with the hand or the foot. To test the double dissociation of language-motor facilitation effects within subjects, Experiments 1 and 2 used a priming procedure where both hand and foot reactions had to be performed in response to different geometrical shapes, which were preceded by action verbs. In Experiment 1, the semantics of the verbs could be ignored whereas Experiment 2 included semantic decisions. Only Experiment 2 revealed a clear double dissociation in reaction times: reactions were facilitated when preceded by verbs describing actions with the matching effector. In Experiment 1, by contrast, there was an interaction between verb-response congruence and a semantic variable related to motor features of the verbs. Thus, the double dissociation paradigm of semantic motor priming was effective, corroborating the role of the motor system in action-related language processing. Importantly, this effect was body part specific. Copyright © 2017 Elsevier B.V. All rights reserved.

Motor Skill Development in Italian Pre-School Children Induced by Structured Activities in a Specific Playground.

Science.gov (United States)

Tortella, Patrizia; Haga, Monika; Loras, Håvard; Sigmundsson, Hermundur; Fumagalli, Guido

2016-01-01

This study examined the effects and specificity of structured and unstructured activities played at the playground Primo Sport 0246 in Northern Italy on motor skill competence in five years old children. The playground was specifically designed to promote gross motor skills in preschool children; in this study 71 children from local kindergartens came to the park once a week for ten consecutive weeks and were exposed to 30 minutes of free play and 30 minutes of structured activities. Before and after the ten visits, each child completed nine tests to assess levels of motor skills, three for fine-motor skills and six for gross-motor skills. As control, motor skills were also assessed on 39 children from different kindergartens who did not come to the park. The results show that the experimental group who practiced gross-motor activities in the playground for 1 hour a week for 10 weeks improved significantly in 4 out of the 6 gross motor tasks and in none of the fine motor tasks. The data indicate that limited transfer occurred between tasks referring to different domains of motor competences while suggesting cross feeding for improvement of gross-motor skills between different exercises when domains related to physical fitness and strength of specific muscle groups are involved. These results are relevant to the issue of condition(s) appropriate for maintaining and developing motor skills in this age group as well as for the planning, organization and implementation of play and physical activities in kindergartens.

Motor Skill Development in Italian Pre-School Children Induced by Structured Activities in a Specific Playground.

Directory of Open Access Journals (Sweden)

Patrizia Tortella

Full Text Available This study examined the effects and specificity of structured and unstructured activities played at the playground Primo Sport 0246 in Northern Italy on motor skill competence in five years old children. The playground was specifically designed to promote gross motor skills in preschool children; in this study 71 children from local kindergartens came to the park once a week for ten consecutive weeks and were exposed to 30 minutes of free play and 30 minutes of structured activities. Before and after the ten visits, each child completed nine tests to assess levels of motor skills, three for fine-motor skills and six for gross-motor skills. As control, motor skills were also assessed on 39 children from different kindergartens who did not come to the park. The results show that the experimental group who practiced gross-motor activities in the playground for 1 hour a week for 10 weeks improved significantly in 4 out of the 6 gross motor tasks and in none of the fine motor tasks. The data indicate that limited transfer occurred between tasks referring to different domains of motor competences while suggesting cross feeding for improvement of gross-motor skills between different exercises when domains related to physical fitness and strength of specific muscle groups are involved. These results are relevant to the issue of condition(s appropriate for maintaining and developing motor skills in this age group as well as for the planning, organization and implementation of play and physical activities in kindergartens.

Motor Skill Development in Italian Pre-School Children Induced by Structured Activities in a Specific Playground

Science.gov (United States)

Tortella, Patrizia; Haga, Monika; Loras, Håvard

2016-01-01

This study examined the effects and specificity of structured and unstructured activities played at the playground Primo Sport 0246 in Northern Italy on motor skill competence in five years old children. The playground was specifically designed to promote gross motor skills in preschool children; in this study 71 children from local kindergartens came to the park once a week for ten consecutive weeks and were exposed to 30 minutes of free play and 30 minutes of structured activities. Before and after the ten visits, each child completed nine tests to assess levels of motor skills, three for fine-motor skills and six for gross-motor skills. As control, motor skills were also assessed on 39 children from different kindergartens who did not come to the park. The results show that the experimental group who practiced gross-motor activities in the playground for 1 hour a week for 10 weeks improved significantly in 4 out of the 6 gross motor tasks and in none of the fine motor tasks. The data indicate that limited transfer occurred between tasks referring to different domains of motor competences while suggesting cross feeding for improvement of gross-motor skills between different exercises when domains related to physical fitness and strength of specific muscle groups are involved. These results are relevant to the issue of condition(s) appropriate for maintaining and developing motor skills in this age group as well as for the planning, organization and implementation of play and physical activities in kindergartens. PMID:27462985

Interaction of language processing and motor skill in children with specific language impairment.

Science.gov (United States)

DiDonato Brumbach, Andrea C; Goffman, Lisa

2014-02-01

To examine how language production interacts with speech motor and gross and fine motor skill in children with specific language impairment (SLI). Eleven children with SLI and 12 age-matched peers (4-6 years) produced structurally primed sentences containing particles and prepositions. Utterances were analyzed for errors and for articulatory duration and variability. Standard measures of motor, language, and articulation skill were also obtained. Sentences containing particles, as compared with prepositions, were less likely to be produced in a priming task and were longer in duration, suggesting increased difficulty with this syntactic structure. Children with SLI demonstrated higher articulatory variability and poorer gross and fine motor skills compared with aged-matched controls. Articulatory variability was correlated with generalized gross and fine motor performance. Children with SLI show co-occurring speech motor and generalized motor deficits. Current theories do not fully account for the present findings, though the procedural deficit hypothesis provides a framework for interpreting overlap among language and motor domains.

An efficient linear power generator - Linear motor for oscillating piston machines; Effizienter Lineargenerator / Linearmotor fuer Kolbenmaschine - Schlussbericht

Energy Technology Data Exchange (ETDEWEB)

Lindegger, M.

2008-07-01

When an oscillating piston interacts with an electrical generator or motor, it is obvious that the electrical machine should also have linear motion, eliminating the disadvantage of a crankshaft. This work has two parts: construction of an efficient linear generator for a Stirling engine with a free piston and a theoretical study of the efficiency of linear motors for driving compressors. The Stirling engine and the linear generator have a continuous power of 1.3 kW{sub el}. With thermal peak power the planned 1.5 kW{sub el} are attained. The Project 'Stirling Free Piston Generator' for cogeneration will continue. Smaller linear motors with permanent magnets function without electronic control from single-phase AC net. The theoretical study shows how linear motors can be led out by linking the electric vector diagram with the pressure-volume diagram of the compressor. At a power level exceeding a few kW, a three-phase system with power electronics is more suitable. The frequency of oscillation is variable and lower than 50 Hz. The efficiency of the simulated linear motors lies in the range of efficiency class EFF1 of standard motors. The very high efficiencies of rotating motors with permanent magnets are not attained. The combination of the linear motor with an optimised thermal process leads to advantages regarding the efficiency. If a heat pump with linear drive system can operate with hot lubricating oil the losses in the heat exchangers are reduced. The Competence Center for Thermal Machines at Lucerne University of Applied Sciences and Arts shows great interest to pursue the project of a linear heat pump for small temperature differences. (author)

Computer Aided Modeling and Analysis of Five-Phase PMBLDC Motor Drive for Low Power High Torque Application

Directory of Open Access Journals (Sweden)

M. A. Inayathullaah

2014-01-01

Full Text Available In order to achieve high torque at low power with high efficiency, a new five-phase permanent magnet brushless DC (PMBLDC motor design was analyzed and optimized. A similar three-phase motor having the same D/L ratio (inner diameter (D and length of the stator (L is compared for maximum torque and torque ripple of the designed five-phase PMBLDC motor. Maxwell software was used to build finite element simulation model of the motor. The internal complicated magnetic field distribution and dynamic performance simulation were obtained in different positions. No load and load characteristics of the five-phase PMBLDC motor were simulated, and the power consumption of materials was computed. The conformity of the final simulation results indicates that this method can be used to provide a theoretical basis for further optimal design of this new type of motor with its drive so as to improve the starting torque and reduce torque ripple of the motor.

Effect of power quality on windings temperature of marine induction motors. Part I: Machine model

Energy Technology Data Exchange (ETDEWEB)

Gnacinski, P. [Gdynia Maritime Univ., Dept. of Ship Electrical Power Engineering, Morska Str. 83, 81-225 Gdynia (Poland)

2009-10-15

Marine induction machines are exposed to various power quality disturbances appearing simultaneously in ship power systems: frequency and voltage rms value deviation, voltage unbalance and voltage waveform distortions. As a result, marine induction motors can be seriously overheated due to lowered supply voltage quality. Improvement of the protection of marine induction machines requires an appropriate method of power quality assessment and modification of the power quality regulations of ship classification societies. This paper presents an analytical model of an induction cage machine supplied with voltage of lowered quality, used in part II of the work (effect of power quality on windings temperature of marine induction motors. Part II. Results of investigations and recommendations for related regulations) for power quality assessment in ship power systems, and for justification of the new power quality regulations proposal. The presented model is suitable for implementation in an on-line measurement system. (author)

Development of Digital Control for High Power Permanent-Magnet Synchronous Motor Drives

Directory of Open Access Journals (Sweden)

Ming-Hung Chen

2014-01-01

Full Text Available This paper is concerned with the development of digital control system for high power permanent-magnet synchronous motor (PMSM to yield good speed regulation, low current harmonic, and stable output speed. The design of controller is conducted by digitizing the mathematical model of PMSM using impulse invariance technique. The predicted current estimator, which is insensitive to motor feedback currents, is proposed to function under stationary frame for harmonic current suppression. In the AC/DC power converter, mathematical model and dc-link voltage limit of the three-phase switch-mode rectifier are derived. In addition, a current controller under synchronous frame is introduced to reduce the current harmonics and increase the power factor on the input side. A digital control system for 75 kW PMSM is realized with digital signal processor (R5F5630EDDFP. Experimental results indicate that the total harmonic distortion of current is reduced from 4.1% to 2.8% for 50 kW output power by the proposed predicted current estimator technique.

Development of a dc motor with virtually zero powered magnetic bearing

Science.gov (United States)

1971-01-01

The development of magnetic bearings for use in direct current electric motors is discussed. The characteristics of the magnets used in the construction of the bearings are described. A magnetic bearing using steel armoring on permanent magnets was selected for performance tests. The specifications of the motor are presented. The test equipment used in the evaluation is described.

Influence of big power motors for irrigation of electric systems

International Nuclear Information System (INIS)

Shimoda, M.; Gialuca, V.; Trombetta, O.R.

1988-01-01

The evolution of rural electrification in CPFL - Companhia Paulista de Forca e Luz, Sao Paulo State, Brazil, and the influence of big power motors installation for irrigation in electric system are shown. Considerations about rural market, energy consumption, planning of distribution and transmission line and some calculations are also presented. (author)

Learning trajectories for speech motor performance in children with specific language impairment.

Science.gov (United States)

Richtsmeier, Peter T; Goffman, Lisa

2015-01-01

Children with specific language impairment (SLI) often perform below expected levels, including on tests of motor skill and in learning tasks, particularly procedural learning. In this experiment we examined the possibility that children with SLI might also have a motor learning deficit. Twelve children with SLI and thirteen children with typical development (TD) produced complex nonwords in an imitation task. Productions were collected across three blocks, with the first and second blocks on the same day and the third block one week later. Children's lip movements while producing the nonwords were recorded using an Optotrak camera system. Movements were then analyzed for production duration and stability. Movement analyses indicated that both groups of children produced shorter productions in later blocks (corroborated by an acoustic analysis), and the rate of change was comparable for the TD and SLI groups. A nonsignificant trend for more stable productions was also observed in both groups. SLI is regularly accompanied by a motor deficit, and this study does not dispute that. However, children with SLI learned to make more efficient productions at a rate similar to their peers with TD, revealing some modification of the motor deficit associated with SLI. The reader will learn about deficits commonly associated with specific language impairment (SLI) that often occur alongside the hallmark language deficit. The authors present an experiment showing that children with SLI improved speech motor performance at a similar rate compared to typically developing children. The implication is that speech motor learning is not impaired in children with SLI. Copyright © 2015 Elsevier Inc. All rights reserved.

Task-specific compensation and recovery following focal motor cortex lesion in stressed rats.

Science.gov (United States)

Kirkland, Scott W; Smith, Lori K; Metz, Gerlinde A

2012-03-01

One reason for the difficulty to develop effective therapies for stroke is that intrinsic factors, such as stress, may critically influence pathological mechanisms and recovery. In cognitive tasks, stress can both exaggerate and alleviate functional loss after focal ischemia in rodents. Using a comprehensive motor assessment in rats, this study examined if chronic stress and corticosterone treatment affect skill recovery and compensation in a task-specific manner. Groups of rats received daily restraint stress or oral corticosterone supplementation for two weeks prior to a focal motor cortex lesion. After lesion, stress and corticosterone treatments continued for three weeks. Motor performance was assessed in two skilled reaching tasks, skilled walking, forelimb inhibition, forelimb asymmetry and open field behavior. The results revealed that persistent stress and elevated corticosterone levels mainly limit motor recovery. Treated animals dropped larger amounts of food in successful reaches and showed exaggerated loss of forelimb inhibition early after lesion. Stress also caused a moderate, but non-significant increase in infarct size. By contrast, stress and corticosterone treatments promoted reaching success and other quantitative measures in the tray reaching task. Comparative analysis revealed that improvements are due to task-specific development of compensatory strategies. These findings suggest that stress and stress hormones may partially facilitate task-specific and adaptive compensatory movement strategies. The observations support the notion that hypothalamic-pituitary-adrenal axis activation may be a key determinant of recovery and motor system plasticity after ischemic stroke.

Interaction of Language Processing and Motor Skill in Children with Specific Language Impairment

Science.gov (United States)

DiDonato Brumbach, Andrea C.; Goffman, Lisa

2014-01-01

Purpose: To examine how language production interacts with speech motor and gross and fine motor skill in children with specific language impairment (SLI). Method: Eleven children with SLI and 12 age-matched peers (4-6 years) produced structurally primed sentences containing particles and prepositions. Utterances were analyzed for errors and for…

Specific Deficit in Implicit Motor Sequence Learning following Spinal Cord Injury.

Directory of Open Access Journals (Sweden)

Ayala Bloch

Full Text Available Physical and psychosocial rehabilitation following spinal cord injury (SCI leans heavily on learning and practicing new skills. However, despite research relating motor sequence learning to spinal cord activity and clinical observations of impeded skill-learning after SCI, implicit procedural learning following spinal cord damage has not been examined.To test the hypothesis that spinal cord injury (SCI in the absence of concomitant brain injury is associated with a specific implicit motor sequence learning deficit that cannot be explained by depression or impairments in other cognitive measures.Ten participants with SCI in T1-T11, unharmed upper limb motor and sensory functioning, and no concomitant brain injury were compared to ten matched control participants on measures derived from the serial reaction time (SRT task, which was used to assess implicit motor sequence learning. Explicit generation of the SRT sequence, depression, and additional measures of learning, memory, and intelligence were included to explore the source and specificity of potential learning deficits.There was no between-group difference in baseline reaction time, indicating that potential differences between the learning curves of the two groups could not be attributed to an overall reduction in response speed in the SCI group. Unlike controls, the SCI group showed no decline in reaction time over the first six blocks of the SRT task and no advantage for the initially presented sequence over the novel interference sequence. Meanwhile, no group differences were found in explicit learning, depression, or any additional cognitive measures.The dissociation between impaired implicit learning and intact declarative memory represents novel empirical evidence of a specific implicit procedural learning deficit following SCI, with broad implications for rehabilitation and adjustment.

DC motor operation controlled from a DC/DC power converter in pulse mode with low duty cycle

OpenAIRE

Stefanov, Goce; Kukuseva, Maja; Citkuseva Dimitrovska, Biljana

2016-01-01

In this paper pulse mode of operation of DC motor controlled by DC/DC power converter is analyzed. DC motor operation with time intervals in which the motor operates without output load is of interest. In this mode it is possible the motor to restore energy. Also, in the paper are represented calculations for the amount of the restored energy in the pulse mode operation of the motor for different duty cycles.

Improving motor reliability in nuclear power plants: Volume 1, Performance evaluation and maintenance practices

International Nuclear Information System (INIS)

Subudhi, M.; Gunther, W.E.; Taylor, J.H.; Sugarman, A.C.; Sheets, M.W.

1987-11-01

This report constitutes the first of the three volumes under this NUREG. The report presents recommendations for developing a cost-effective program for performance evaluation and maintenance of electric motors in nuclear power plants. These recommendations are based on current industry practices, available techniques for monitoring degradation in motor components, manufacturer's recommendations, operating experience, and results from two laboratory tests on aged motors. Two laboratory test reports on a small and a large motor are presented in separate volumes of this NUREG. These provide the basis for the various functional indicators recommended for maintenance programs in this report. The overall preventive maintenance program is separated into two broad areas of activity aimed at mitigating the potential effects of equipment aging: Performance Evaluation and Equipment Maintenance. The latter involves actually maintaining the condition of the equipment while the former involves those activities undertaken to monitor degradation due to aging. These monitoring methods are further categorized into periodic testing, surveillance testing, continuous monitoring and inspections. This study focuses on the methods and procedures for performing the above activities to maintain the motors operationally ready in a nuclear facility. This includes an assessment of various functional indicators to determine their suitability for trending to monitor motor component condition. The intrusiveness of test methods and the present state-of-the-art for using the test equipment in a plant environment are discussed. In conclusion, implementation of the information provided in this report, will improve motor reliability in nuclear power plants. The study indicates the kinds of tests to conduct, how and when to conduct them, and to which motors the tests should be applied. 44 refs., 12 figs., 13 tabs

Predictive Direct Torque Control Application-Specific Integrated Circuit of an Induction Motor Drive with a Fuzzy Controller

Directory of Open Access Journals (Sweden)

Guo-Ming Sung

2017-06-01

Full Text Available This paper proposes a modified predictive direct torque control (PDTC application-specific integrated circuit (ASIC of a motor drive with a fuzzy controller for eliminating sampling and calculating delay times in hysteresis controllers. These delay times degrade the control quality and increase both torque and flux ripples in a motor drive. The proposed fuzzy PDTC ASIC calculates the stator’s magnetic flux and torque by detecting the three-phase current, three-phase voltage, and rotor speed, and eliminates the ripples in the torque and flux by using a fuzzy controller and predictive scheme. The Verilog hardware description language was used to implement the hardware architecture, and the ASIC was fabricated by the Taiwan Semiconductor Manufacturing Company through a 0.18-μm 1P6M CMOS process that involved a cell-based design method. The measurements revealed that the proposed fuzzy PDTC ASIC of the three-phase induction motor yielded a test coverage of 96.03%, fault coverage of 95.06%, chip area of 1.81 × 1.81 mm2, and power consumption of 296 mW, at an operating frequency of 50 MHz and a supply voltage of 1.8 V.

Improving motor reliability in nuclear power plants: Volume 3, Failure analysis and diagnostic tests on a naturally aged large electric motor

International Nuclear Information System (INIS)

Subudhi, M.; Taylor, J.H.; Sheets, M.W.

1987-11-01

Stator coils of a naturally failed 400 hp motor from the Brookhaven National Laboratory test reactor facility were tested for their dielectric integrities. The motor was used to drive the primary reactor coolant pump for the last 20 years. Maintenance activities on this motor during its entire service life were minimal, with the exception of meggering it periodically. The stator consisted of ninety individual coils which were separated for testing. Seven different dielectric tests were performed on the coils. Each set of data from the tested coils indicated a spectrum of variation depending on their aging conditions and characteristics. By comparing the test data to baseline data, the test methods were assessed for application to motor maintenance programs in nuclear power plants. Also included in this study are results of an investigation to determine the cause of this motor failure. Recommendations are provided on the aged condition of a second identical primary pump motor which is the same age and presently in operation. Recommendations are also presented relating to each of the dielectric test methods applicability to motor maintenance programs. 6 refs., 11 figs., 5 tabs

A MATHEMATICAL MODEL OF THERMAL POWER PLANTS SMOKE EXHAUSTERS INDUCTION MOTORS SYSTEM OPERATION MODES

Directory of Open Access Journals (Sweden)

K. M. Vasyliv

2017-06-01

Full Text Available Purpose. Development of a model-software complex (MSC for computer analysis of modes of the system of induction motors (IM of smoke exhausters of thermal power plant (TPP, the basic elements of which are mathematical models and corresponding software written in the programming language FORTRAN. Methodology. Mathematical model serves as a system of differential equations of electrical and mechanical condition. The equation of electric state is written in phase coordinates based on Kirchhoff's laws, and mechanical condition described by the d'Alembert equation. Mathematical model focuses on explicit numerical integration methods. Scientific novelty. The equation of state of electrical connections takes into account the mutual electromagnetic circuits for transformer of own needs (TON and induction motors and interdependence (in all possible combinations between: TON (from which motors powered and each of the two IM and blood pressure between themselves. The complex allows to simulate electromagnetic and electromechanical processes in transitional and steady, symmetric and asymmetric modes including modes of self-induction motors. Results. Complex is used for computer analysis of electromagnetic and electromechanical processes and established the basic laws of motion modes of starting, stopping and self-start of IM of smoke exhausters of the TPP unit. Practical value. The complex is suitable for computer analysis of modes of other similar units of own needs of thermal power plants.

Transistorized PWM inverter-induction motor drive system

Science.gov (United States)

Peak, S. C.; Plunkett, A. B.

1982-01-01

This paper describes the development of a transistorized PWM inverter-induction motor traction drive system. A vehicle performance analysis was performed to establish the vehicle tractive effort-speed requirements. These requirements were then converted into a set of inverter and motor specifications. The inverter was a transistorized three-phase bridge using General Electric power Darlington transistors. The description of the design and development of this inverter is the principal object of this paper. The high-speed induction motor is a design which is optimized for use with an inverter power source. The primary feedback control is a torque angle control with voltage and torque outer loop controls. A current-controlled PWM technique is used to control the motor voltage. The drive has a constant torque output with PWM operation to base motor speed and a constant horsepower output with square wave operation to maximum speed. The drive system was dynamometer tested and the results are presented.

Using a micromachined magnetostatic relay in commutating a DC motor

Science.gov (United States)

Tai, Yu-Chong (Inventor); Wright, John A. (Inventor); Lilienthal, Gerald (Inventor)

2004-01-01

A DC motor is commutated by rotating a magnetic rotor to induce a magnetic field in at least one magnetostatic relay in the motor. Each relay is activated in response to the magnetic field to deliver power to at least one corresponding winding connected to the relay. In some cases, each relay delivers power first through a corresponding primary winding and then through a corresponding secondary winding to a common node. Specific examples include a four-pole, three-phase motor in which each relay is activated four times during one rotation of the magnetic rotor.

Analysis of failure and maintenance experiences of motor operated valves in a Finnish nuclear power plant

International Nuclear Information System (INIS)

Simola, K.; Laakso, K.

1992-01-01

Operating experiences from 1981 up to 1989 of totally 104 motor operated closing valves (MOV) in different safety systems at TVO I and II nuclear power units were analysed in a systematic way. The qualitative methods used were failure mode and effects analysis (FMEA) and maintenance effects and criticality analysis (MECA). The failure descriptions were obtained from power plant's computerized failure reporting system. The reported 181 failure events were reanalysed and sorted according to specific classifications developed for the MOV function. Filled FMEA and MECA sheets on individual valves were stored in a microcomputer data base for further analyses. Analyses were performed for the failed mechanical and electrical valve parts, ways of detection of failure modes, failure effects, and repair and unavailability times

Device on a diesel motor to supply power to emergency aggregates

International Nuclear Information System (INIS)

Koch, C.; Boekemeier, V.; Schilling, R.

1977-01-01

The invented arrangement of a diesel motor for the emergency supply of a nuclear power plant ensures that in the case of a fire in the environment of the emergency feeding building, no air with too much flue gas reaches the diesel motor via the suction pipe. The discharge pipe with a nozzle-shaped discharge opening and the suction pipe running above it pass horizontally through a wall of the building. There are vertical walls on both sides of the openings which prevent a sideways flowing of air to the exhaust gas flow in the vicinity of the building. (HGOE) [de

FY2013 Advanced Power Electronics and Electric Motors R&D Annual Progress Report

Energy Technology Data Exchange (ETDEWEB)

Rogers, Susan A. [Dept. of Energy (DOE), Washington DC (United States). Vehicle Technologies Office

2014-02-01

The Advanced Power Electronics and Electric Motors (APEEM) technology area within the DOE Vehicle Technologies Office (VTO) provides support and guidance for many cutting-edge automotive technologies now under development. Research is focused on developing revolutionary new power electronics (PE), electric motor, and traction drive system (TDS) technologies that will leapfrog current on-the-road technologies, leading to lower cost and better efficiency in transforming battery energy to useful work. The research and development (R&D) is also aimed at achieving a greater understanding of and improvements in the way the various new components of tomorrow’s automobiles will function as a unified system to improve fuel efficiency through research in more efficient TDSs.

On the Influence of Piston and Cylinder Density in Tribodynamics of a Radial Piston Digital Fluid Power Displacement Motor

DEFF Research Database (Denmark)

Johansen, Per; Roemer, Daniel Beck; Andersen, Torben O.

2015-01-01

-stroke displacement simulations are used as basis for the parametric analysis. From the parametric analysis a change, in the minimum film thickness as function of piston and cylinder density, is shown for certain operating modes of the digital fluid power displacement motor. This indicate a need for careful....... In this paper the influence of the inertia term on the lubrication gaps of a radial piston motor are studied by a parametric analysis of the piston and cylinder density in a multibody tribodynamic simulation model. The motor is modeled as a digital fluid power displacement machine and a series of full...... assessment of the applicability, of the force balance condition, if it is used in multibody tribodynamic simulations of radial piston digital fluid power displacement motors....

Yield and power of the induction motor operating as generator; Rendimento e potencia do motor de inducao atuando como gerador

Energy Technology Data Exchange (ETDEWEB)

Gomes, Francisco de Salles Cintra [Universidade Paulista (UNIP), Campinas, SP (Brazil)

1997-12-01

This article shows the result of the analysis of two induction motors operating as generators (Park variable for a machine connected to an infinite bar), particularly the yield and power of the machines operating under this condition.

Multi-Objective Optimal Design of Electro-Hydrostatic Actuator Driving Motors for Low Temperature Rise and High Power Weight Ratio

Directory of Open Access Journals (Sweden)

Guo Hong

2018-05-01

Full Text Available With the rapid development of technology, motors have drawn increasing attention in aviation applications, especially in the more electrical aircraft and all electrical aircraft concepts. Power weight ratio and reliability are key parameters for evaluating the performance of equipment applied in aircraft. The temperature rise of the motor is closely related to the reliability of the motor. Therefore, based on Taguchi, a novel multi-objective optimization method for the heat dissipation structural design of an electro-hydrostatic actuator (EHA drive motor was proposed in this paper. First, the thermal network model of the EHA drive motor was established. Second, a sensitivity analysis of the key parameters affecting the cooling performance of the motor was conducted, such as the thickness of fins, the height of fins, the space of fins, the potting materials and the slot fill factor. Third, taking the average temperature of the windings and the power weight ratio as the optimization goal, the multi-objective optimal design of the heat dissipation structure of the motor was carried out by applying Taguchi. Then, a 3-D finite element model of the motor was established and the steady state thermal analysis was carried out. Furthermore, a prototype of the optimal motor was manufactured, and the temperature rise under full load condition tested. The result indicated that the motor with the optimized heat dissipating structure presented a low temperature rise and high power weight ratio, therefore validating the proposed optimization method.

Generalized motor abilities and timing behavior in children with specific language impairment.

Science.gov (United States)

Zelaznik, Howard N; Goffman, Lisa

2010-04-01

To examine whether children with specific language impairment (SLI) differ from normally developing peers in motor skills, especially those skills related to timing. Standard measures of gross and fine motor development were obtained. Furthermore, finger and hand movements were recorded while children engaged in 4 different timing tasks, including tapping and drawing circles in time with a metronome or a visual target. Fourteen children with SLI (age 6 to 8 years) and 14 age-matched peers who were typically developing participated. As expected, children with SLI showed poorer performance on a standardized test of gross and fine motor skill than did their normally developing peers. However, timing skill in the manual domain was equivalent to that seen in typically developing children. Consistent with earlier findings, relatively poor gross and fine motor performance is observed in children with SLI. Surprisingly, rhythmic timing is spared.

Reactor coolant pump testing using motor current signatures analysis

Energy Technology Data Exchange (ETDEWEB)

Burstein, N.; Bellamy, J.

1996-12-01

This paper describes reactor coolant pump motor testing carried out at Florida Power Corporation`s Crystal River plant using Framatome Technologies` new EMPATH (Electric Motor Performance Analysis and Trending Hardware) system. EMPATH{trademark} uses an improved form of Motor Current Signature Analysis (MCSA), technology, originally developed at Oak Ridge National Laboratories, for detecting deterioration in the rotors of AC induction motors. Motor Current Signature Analysis (MCSA) is a monitoring tool for motor driven equipment that provides a non-intrusive means for detecting the presence of mechanical and electrical abnormalities in the motor and the driven equipment. The base technology was developed at the Oak Ridge National Laboratory as a means for determining the affects of aging and service wear specifically on motor-operated valves used in nuclear power plant safety systems, but it is applicable to a broad range of electric machinery. MCSA is based on the recognition that an electric motor (ac or dc) driving a mechanical load acts as an efficient and permanently available transducer by sensing mechanical load variations, large and small, long-term and rapid, and converting them into variations in the induced current generated in the motor windings. The motor current variations, resulting from changes in load caused by gears, pulleys, friction, bearings, and other conditions that may change over the life of the motor, are carried by the electrical cables powering the motor and are extracted at any convenient location along the motor lead. These variations modulate the 60 Hz carrier frequency and appear as sidebands in the spectral plot.

DC Motor control using motor-generator set with controlled generator field

Science.gov (United States)

Belsterling, Charles A.; Stone, John

1982-01-01

A d.c. generator is connected in series opposed to the polarity of a d.c. power source supplying a d.c. drive motor. The generator is part of a motor-generator set, the motor of which is supplied from the power source connected to the motor. A generator field control means varies the field produced by at least one of the generator windings in order to change the effective voltage output. When the generator voltage is exactly equal to the d.c. voltage supply, no voltage is applied across the drive motor. As the field of the generator is reduced, the drive motor is supplied greater voltage until the full voltage of the d.c. power source is supplied when the generator has zero field applied. Additional voltage may be applied across the drive motor by reversing and increasing the reversed field on the generator. The drive motor may be reversed in direction from standstill by increasing the generator field so that a reverse voltage is applied across the d.c. motor.

Effects of motor programming on the power spectral density function of finger and wrist movements

NARCIS (Netherlands)

Van Galen, G P; Van Doorn, R R; Schomaker, L R

Power spectral density analysis was applied to the frequency content of the acceleration signal of pen movements in line drawing. The relative power in frequency bands between 1 and 32 Hz was measured as a function of motoric and anatomic task demands. Results showed a decrease of power at the lower

Electric motor for laser-mechanical drilling

Science.gov (United States)

Grubb, Daryl L.; Faircloth, Brian O.; Zediker, Mark S.

2015-07-07

A high power laser drilling system utilizing an electric motor laser bottom hole assembly. A high power laser beam travels within the electric motor for advancing a borehole. High power laser drilling system includes a down hole electrical motor having a hollow rotor for conveying a high power laser beam through the electrical motor.

Common-mode Voltage Reduction in a Motor Drive System with a Power Factor Correction

DEFF Research Database (Denmark)

Adabi, J.; Boora, A.A.; Zare, F.

2012-01-01

Common-mode voltage generated by a power converter in combination with parasitic capacitive couplings is a potential source of shaft voltage in an AC motor drive system. In this study, a three-phase motor drive system supplied with a single-phase AC-DC diode rectifier is investigated in order...... to reduce shaft voltage in a three-phase AC motor drive system. In this topology, the AC-DC diode rectifier influences the common-mode voltage generated by the inverter because the placement of the neutral point is changing in different rectifier circuit states. A pulse width modulation technique...

The rewritable effects of bonded magnet for large starting torque and high efficiency in the small power single-phase written pole motor

Science.gov (United States)

Choi, Jae-Hak; Lee, Sung-Ho

2009-04-01

This paper presents a single-phase written pole motor using a bonded ring magnet for the small power home application. The motor has an exciter pole structure inside the stator and hybrid characteristics of an induction motor and permanent magnet motor. The design parameters and operating characteristics of the hybrid concept motor are investigated to increase starting torque and efficiency, which is most important for the small power home application. Larger starting torque and higher efficiency than those of the conventional induction motor could be obtained by using the rewritable characteristics of bonded magnet on the starting and running conditions.

Impedance calculations for power cables to primary coolant pump motors

International Nuclear Information System (INIS)

Hegerhorst, K.B.

1977-01-01

The LOFT primary system motor generator sets are located in Room B-239 and are connected to the primary coolant pumps by means of a power cable. The calculated average impedance of this cable is 0.005323 ohms per unit resistance and 0.006025 ohms per unit reactance based on 369.6 kVA and 480 volts. The report was written to show the development of power cable parameters that are to be used in the SICLOPS (Simulation of LOFT Reactor Coolant Loop Pumping System) digital computer program as written in LTR 1142-16 and also used in the pump coastdowns for the FSAR Analysis

Brushless DC motor drives supplied by PV power system based on Z-source inverter and FL-IC MPPT controller

International Nuclear Information System (INIS)

Mozaffari Niapour, S.A.KH.; Danyali, S.; Sharifian, M.B.B.; Feyzi, M.R.

2011-01-01

Highlights: → Employing the BLDC motor in water pumping systems. → Utilizing the ZSI as a single-stage power converter in the PV water pumping systems based on BLDC motor. → Improvement of the conventional IC MPPT method with the fuzzy logic control scheme to save more energy from the PV array. → Taking the advantages of the DTC drive of the BLDC motor. → Optimizing the water pumping system speed response characteristic by PSO. - Abstract: This paper discusses operation performance of a water pumping system consist of a brushless dc (BLDC) motor coupled a centrifugal pump and accompanying a Z-source inverter (ZSI) fed by a photovoltaic (PV) array, to be improved. Despite conventional double-stage power converters, this paper proposes utilizing a single-stage ZSI to extract the maximum power of the PV array and supply the BLDC motor simultaneously. Utilizing the ZSI provides some inherent advantages such as high efficiency and low cost, which is very promising for PV systems due to its novel voltage buck/boost capability. In addition, in order to precisely perform the maximum power point tracking (MPPT) of the PV array the fuzzy logic-incremental conductance (FL-IC) MPPT scheme is proposed. The proposed FL-IC MPPT scheme provides enough modification to the conventional IC method to enjoy an appropriate variable step size MPPT control signal for the ZSI. Moreover, direct torque control (DTC) is found more effective in comparison with hysteresis current control with current shaping to drive the BLDC motor, because it benefits from faster torque response, reduced torque ripple, less sensitivity to parameters variations, and simple implementation. In the mean time, due to the frequently variations of the PV power generation; delivered mechanical power to the centrifugal pump is variable. Thus, the BLDC motor should be driven with variable reference speed. In order to improve the speed transient response of the BLDC motor and enhance the energy saving aspect of

Is generic physical activity or specific exercise associated with motor abilities?

Science.gov (United States)

Rinne, Marjo; Pasanen, Matti; Miilunpalo, Seppo; Mälkiä, Esko

2010-09-01

Evidence of the effect of leisure time physical activity (LTPA) modes on the motor abilities of a mature population is scarce. The purpose of this study was to compare the motor abilities of physically active and inactive men and women and to examine the associations of different exercise modes and former and recent LTPA (R-LTPA) with motor ability and various physical tests. The LTPA of the participants (men n = 69, women n = 79; aged 41-47 yr) was ascertained by a modified Physical Activity Readiness Questionnaire, including questions on the frequency, duration, and intensity of R-LTPA and former LTPA and on exercise modes. Motor abilities in terms of balance, agility, and coordination were assessed with a battery of nine tests supplemented with five physical fitness tests. Multiple statistical methods were used in analyses that were conducted separately for men and women. The MET-hours per week of R-LTPA correlated statistically significantly with the tests of agility and static balance (rs = -0.28, P = 0.022; rs = -0.25, P = 0.043, respectively) among men and with the static balance (rs = 0.41), 2-km walking (rs = 0.36), step squat (rs = 0.36) (P women. In the stepwise regression among men, the most frequent statistically significant predictor was the playing of several games. For women, a history of LTPA for more than 3 yr was the strongest predictor for good results in almost all tests. Participants with long-term and regular LTPA had better motor performance, and especially a variety of games improve components of motor ability. Diverse, regular, and long-term exercise including both specific training and general activity develops both motor abilities and physical fitness.

Implicit sequence-specific motor learning after sub-cortical stroke is associated with increased prefrontal brain activations: An fMRI study

Science.gov (United States)

Meehan, Sean K.; Randhawa, Bubblepreet; Wessel, Brenda; Boyd, Lara A.

2010-01-01

Implicit motor learning is preserved after stroke, but how the brain compensates for damage to facilitate learning is unclear. We used a random effects analysis to determine how stroke alters patterns of brain activity during implicit sequence-specific motor learning as compared to general improvements in motor control. Nine healthy participants and 9 individuals with chronic, right focal sub-cortical stroke performed a continuous joystick-based tracking task during an initial fMRI session, over 5 days of practice, and a retention test during a separate fMRI session. Sequence-specific implicit motor learning was differentiated from general improvements in motor control by comparing tracking performance on a novel, repeated tracking sequences during early practice and again at the retention test. Both groups demonstrated implicit sequence-specific motor learning at the retention test, yet substantial differences were apparent. At retention, healthy control participants demonstrated increased BOLD response in left dorsal premotor cortex (BA 6) but decreased BOLD response left dorsolateral prefrontal cortex (DLPFC; BA 9) during repeated sequence tracking. In contrast, at retention individuals with stroke did not show this reduction in DLPFC during repeated tracking. Instead implicit sequence-specific motor learning and general improvements in motor control were associated with increased BOLD response in the left middle frontal gyrus BA 8, regardless of sequence type after stroke. These data emphasize the potential importance of a prefrontal-based attentional network for implicit motor learning after stroke. The present study is the first to highlight the importance of the prefrontal cortex for implicit sequence-specific motor learning after stroke. PMID:20725908

Assessment of Psychophysiological Response and Specific Fine Motor Skills in Combat Units.

Science.gov (United States)

Sánchez-Molina, Joaquín; Robles-Pérez, José J; Clemente-Suárez, Vicente J

2018-03-02

Soldiers´ training and experience can influence the outcome of the missions, as well as their own physical integrity. The objective of this research was to analyze the psycho-physiological response and specific motor skills in an urban combat simulation with two units of infantry with different training and experience. psychophysiological parameters -Heart Rate, blood oxygen saturation, glucose and blood lactate, cortical activation, anxiety and heart rate variability-, as well as fine motor skills were analyzed in 31 male soldiers of the Spanish Army, 19 belonging to the Light Infantry Brigade, and 12 to the Heavy Forces Infantry Brigade, before and after an urban combat simulation. A combat simulation provokes an alteration of the psycho-physiological basal state in soldiers and a great unbalance in the sympathetic-vagal interaction. The specific training of Light Infantry unit involves lower metabolic, cardiovascular, and anxiogenic response not only previous, but mainly after a combat maneuver, than Heavy Infantry unit's. No differences were found in relation with fine motor skills, improving in both cases after the maneuver. This fact should be taken into account for betterment units´ deployment preparation in current theaters of operations.

Extending the Constant Power Speed Range of the Brushless DC Motor through Dual Mode Inverter Control -- Part I: Theory and Simulation

International Nuclear Information System (INIS)

Lawler, J.S.

2001-01-01

An inverter topology and control scheme has been developed that can drive low-inductance, surface-mounted permanent magnet motors over the wide constant power speed range required in electric vehicle applications. This new controller is called the dual-mode inverter control (DMIC)[1]. The DMIC can drive either the Permanent Magnet Synchronous Machine (PMSM) with sinusoidal back emf, or the brushless dc machine (BDCM) with trapezoidal emf in the motoring and regenerative braking modes. In this paper we concentrate on the BDCM under high-speed motoring conditions. Simulation results show that if all motor and inverter loss mechanisms are neglected, the constant power speed range of the DMIC is infinite. The simulation results are supported by closed form expressions for peak and rms motor current and average power derived from analytical solution to the differential equations governing the DMIC/BDCM drive for the lossless case. The analytical solution shows that the range of motor inductance that can be accommodated by the DMIC is more than an order of magnitude such that the DMIC is compatible with both low- and high-inductance BDCMs. Finally, method is given for integrating the classical hysteresis band current control, used for motor control below base speed, with the phase advance of DMIC that is applied above base speed. The power versus speed performance of the DMIC is then simulated across the entire speed range

DIAGNOSING OF BASIC AND SPECIFIC MOTORIC CAPABILITIES AT THE YOUTH OF THE BASKETBALL SCHOOL

Directory of Open Access Journals (Sweden)

Florian Miftari

2015-05-01

Full Text Available In general the problematic of diagnosing basic and specific motor movement information of the basketball game in found in the works of a considerable number of world authors. In this work a youth population of an age group between 13-14 years old will be treated. The total number of participants is defined to an amount of 100 of young basketball players, members of two different basketball academies. In this experiment, the subjects will conduct tests in 5 basic motor skills variables such as: 1. Steady Jump in length, 2 steady jump in height 3.20 meters run from a steady start, 4. Medicine Ball Throw and 5. Agility Test. While from specific motor movement skills are included: 1.20 Meters run with ball, 2. Basketball shooting for 30 seconds round-trip,3. Anaerobic durability with and without ball (kamikaze 4. Intensive Basketball shots-Change of direction and 5. Basketball shots from five positions. Subject to the number of subjects that will be treated in this study, their age and the amount of variables tested, the main objectives of this study, will be limited to achieving the goals. On the basis of test results, it can be concluded that there are no significant differences in the basic motor parameters between the two groups G1 and G2, mostly due to systematic practice effects rather than academy belonging itself.In the other hand, differences between the two groups in the specific basketball motor skills can be clearly identified, in typical basketball movement situations.In addition, comparing the test results of the individuals tested for the purpose if this diagnosis, a much more advanced level of motor skills compared to the normal population of the same group age that don’t engage in basketball activities can be identified. This experimental study carried out in the youth in the age group of 13(-+ 6 months years old that continuously in a systematic manner attend basketball academies in two different basketball schools, with

Power technology complex for production of motor fuel from brown coals with power supply from NPPs

International Nuclear Information System (INIS)

Troyanov, M.F.; Poplavskij, V.M.; Sidorov, G.I.; Bondarenko, A.V.; Chebeskov, A.N.; Chushkin, V.N.; Karabash, A.A.; Krichko, A.A.; Maloletnev, A.S.

1998-01-01

With the present-day challenge of efficient use of low-grade coals and current restructuring of coal industry in the Russian Federation, it is urgent to organise the motor fuel production by the synthesis from low grade coals and heavy petroleum residues. With this objective in view, the Institute of Physics and Power Engineering of RF Minatom and Combustible Resources Institute of RF Mintopenergo proposed a project of a standard nuclear power technology complex for synthetic liquid fuel (SLF) production using fast neutron reactors for power supply. The proposed project has two main objectives: (1) Engineering and economical optimization of the nuclear power supply for SLF production; and (2) Engineering and economical optimization of the SLF production by hydrogenisation of brown coals and heavy petroleum residues with a complex development of advanced coal chemistry. As a first approach, a scheme is proposed with the use of existing reactor cooling equipment, in particular, steam generators of BN-600, limiting the effect on safety of reactor facility operation at minimum in case of deviations and abnormalities in the operation of technological complex. The possibility to exclude additional requirements to the equipment for nuclear facility cooling was also taken into account. It was proposed to use an intermediate steam-water circuit between the secondary circuit sodium and the coolant to heat the technological equipment. The only change required for the BN-600 equipment will be the replacement of sections of intermediate steam superheaters at the section of main steam superheaters. The economic aspects of synthetic motor fuel production proposed by the joint project depend on the evaluation of integral balances: thermal power engineering, chemical technology, the development of advanced large scale coal chemistry of high profitability; utilisation of ash and precious microelements in waste-free technology; production of valuable isotopes; radical solution of

THE INFLUENCE OF CERTAIN TESTS FOR EVALUATING THE ANTROPOMETRIC, MOTOR AND SPECIFIC MOTOR DIMENSIONS ON THE ELEMENTS OF THE ATTACK IN SPORT KARATE FIGHTING

Directory of Open Access Journals (Sweden)

Žarko Kostovski

2011-08-01

Full Text Available The research involved 48 participants - top male karate competitors, juniors from karate clubs from Republic of Macedonia. The subject of this research are the defining elements of karate attack in sports karate fighting, and the basic aim is to establish the influence of anthropometric, motor and specific motor dimensions on the karate elements that use in sport karate fighting. In the research were used 36 variables: 4 antropomotorical variables, 4 variables for estimate on the explosive strength, 4 variables for estimate on the segmentary speed (movement frequency, 12 variables of the specific karate elements used in the sport karate fighting and 12 variables for estimate on the specifically karate abilities in 3 motor space: 4 variables for estimate on the specific karate coordination, 4 variables for estimate on the specific karate precision and 4 variables for estimate on the specific karate balance, which are predictive system of variables. The criterion set of variables of this research are represented by 4 karate elements which define the attack in sports karate fighting. From the received results was determined existing of groups in the different spaces of the treated variables and influence of the predictive system of variables on the criterion set of variables

Failure analysis of motor bearing of sea water pump in nuclear power plant

International Nuclear Information System (INIS)

Bian Chunhua; Zhang Wei

2015-01-01

The motor bearing of sea water pump in Qinshan Phase II Nuclear Power plant broke after only one year's using. This paper introduces failure analysis process of the motor bearing. Chemical composition analysis, metallic phase analysis, micrographic examination, and hardness analysis, dimension analysis of each part of the bearing, as well as the high temperature and low temperature performance analysis of lubricating grease are performed. According to the analysis above mentioned, the failure mode of the bearing is wearing, and the reason of wearing is inappropriate installation of the bearing. (authors)

Electric motor for laser-mechanical drilling

Science.gov (United States)

Grubb, Daryl L.; Faircloth, Brian O.; Zediker, Mark S.

2017-10-10

A high power laser drilling system utilizing an electric motor laser bottom hole assembly. A high power laser beam travels within the electric motor for performing a laser operation. A system includes a down hole electrical motor having a hollow rotor for conveying a high power laser beam having a wavelength less than 1060 nm through the electrical motor.

Specific power of liquid-metal-cooled reactors

International Nuclear Information System (INIS)

Dobranich, D.

1987-10-01

Calculations of the core specific power for conceptual space-based liquid-metal-cooled reactors, based on heat transfer considerations, are presented for three different fuel types: (1) pin-type fuel; (2) cermet fuel; and (3) thermionic fuel. The calculations are based on simple models and are intended to provide preliminary comparative results. The specific power is of interest because it is a measure of the core mass required to produce a given amount of power. Potential problems concerning zero-g critical heat flux and loss-of-coolant accidents are also discussed because these concerns may limit the core specific power. Insufficient experimental data exists to accurately determine the critical heat flux of liquid-metal-cooled reactors in space; however, preliminary calculations indicate that it may be a concern. Results also indicate that the specific power of the pin-type fuels can be increased significantly if the gap between the fuel and the clad is eliminated. Cermet reactors offer the highest specific power because of the excellent thermal conductivity of the core matrix material. However, it may not be possible to take fuel advantage of this characteristic when loss-of-coolant accidents are considered in the final core design. The specific power of the thermionic fuels is dependent mainly on the emitter temperature. The small diameter thermionic fuels have specific powers comparable to those of pin-type fuels. 11 refs., 12 figs, 2 tabs

Power system for tokamak fusion experiments. Motor generator with flywheel effect

International Nuclear Information System (INIS)

Miyachi, Kengo

1997-01-01

JT-60 requires an enormous electric power pulse about 1,300 MVA periodically for its plasma initiation, containment and heating. JT-60 could not receive all electric power from a commercial line for plasma experiment except about 160 MVA because the 275 kV commercial line has some limitations. Therefore JT-60 needs huge electric power sources. The power supply system of JT-60 has 3 motor generators (MG). The total capacity of MG is 1,115 MVA that consists of a toroidal MG (TMG), poloidal MG (PMG) and Heating power supply MG (HMG), and each MG has a huge flywheel effect. For example, TMG has a 4.02 GJ energy yield that consists of 6 disk flywheel. The total weight of flywheel of TMG is 650 ton. This report describes the structure, operating system, and maintenance history of 3 types of MG. (author)

Development of method for detecting signs deterioration in insulator of high-voltage motors. 2. Test Results of a new on-line partial discharge monitor for high-voltage motors in nuclear power stations

International Nuclear Information System (INIS)

Tochio, Atsushi; Kaneda, Yoshiharu; Urakawa, Nobuo

2000-01-01

For the purpose of early detection of deterioration of insulators in high-voltage motors which are widely utilized in nuclear power stations, a new on-line partial discharge (PD) monitor was developed and was tested for sixteen motors which were practically running in nuclear power stations. From the test results, it is seen that (1) good signal to noise ratio is obtained by adopting a two frequency correlation method, (2) a resistance temperature detector (RTD) in a motor has sufficient sensitivity to detect PD, (3) when RTD is not installed or is unable to use for this purpose, a radio frequency current transformer (RFCT) can be utilized, although its sensitivity is about 1/10 of that of the RTD monitor. Finally we found a good correlation between the results of this on-line method and the conventional off-line method in which the insulator resistance of a concerned motor was measured during its shut-down, and thereby we demonstrated that this method could be applicable to the on-line test of high-voltage motors in nuclear power stations. (author)

Motor modules during adaptation to walking in a powered ankle exoskeleton.

Science.gov (United States)

Jacobs, Daniel A; Koller, Jeffrey R; Steele, Katherine M; Ferris, Daniel P

2018-01-03

Modules of muscle recruitment can be extracted from electromyography (EMG) during motions, such as walking, running, and swimming, to identify key features of muscle coordination. These features may provide insight into gait adaptation as a result of powered assistance. The aim of this study was to investigate the changes (module size, module timing and weighting patterns) of surface EMG data during assisted and unassisted walking in an powered, myoelectric, ankle-foot orthosis (ankle exoskeleton). Eight healthy subjects wore bilateral ankle exoskeletons and walked at 1.2 m/s on a treadmill. In three training sessions, subjects walked for 40 min in two conditions: unpowered (10 min) and powered (30 min). During each session, we extracted modules of muscle recruitment via nonnegative matrix factorization (NNMF) from the surface EMG signals of ten muscles in the lower limb. We evaluated reconstruction quality for each muscle individually using R 2 and normalized root mean squared error (NRMSE). We hypothesized that the number of modules needed to reconstruct muscle data would be the same between conditions and that there would be greater similarity in module timings than weightings. Across subjects, we found that six modules were sufficient to reconstruct the muscle data for both conditions, suggesting that the number of modules was preserved. The similarity of module timings and weightings between conditions was greater then random chance, indicating that muscle coordination was also preserved. Motor adaptation during walking in the exoskeleton was dominated by changes in the module timings rather than module weightings. The segment number and the session number were significant fixed effects in a linear mixed-effect model for the increase in R 2 with time. Our results show that subjects walking in a exoskeleton preserved the number of modules and the coordination of muscles within the modules across conditions. Training (motor adaptation within the session and

Apparatus for servicing an eleongated suspended pump motor in an electric power plant with limited access

International Nuclear Information System (INIS)

Chavez, R.; Johnson, F.T.; Ekeroth, D.E.; Matusz, J.M.

1994-01-01

Elongated coolant pump motors suspended under steam generators within containment in a power plant with limited access space, are removed and replaced by an upright elongated maintenance cart with an elongated opening along one side in which the motor is received. Rollers support the cart for conveying the elongated motor in an upright position out from under the steam generator and onto an elevator. The elevator is lowered to transfer support of the cart and motor through trunnions to saddles straddling the elevator for rotation of the cart to a generally horizontal position. The elevator then raises the horizontally disposed cart carrying the motor to a higher floor where it is rolled off the elevator on rollers and out through the auxiliary equipment hatch. The cart includes a top V-shaped collar for supporting the motor, and a further lower support cradle operative when the cart is horizontal. Jacks support the motor during unbolting from the pump casing and lower it onto the cart. (Author)

Self-powered suspension criterion and energy regeneration implementation scheme of motor-driven active suspension

Science.gov (United States)

Yan, Shuai; Sun, Weichao

2017-09-01

Active suspension systems have advantages on mitigating the effects of vehicle vibration caused by road roughness, which are one of the most important component parts in influencing the performances of vehicles. However, high amount of energy consumption restricts the application of active suspension systems. From the point of energy saving, this paper presents a self-powered criterion of the active suspension system to judge whether a motor-driven suspension can be self-powered or not, and then a motor parameter condition is developed as a reference to design a self-powered suspension. An energy regeneration implementation scheme is subsequently proposed to make the active suspension which has the potential to be self-powered achieve energy-saving target in the real application. In this implementation scheme, operating electric circuits are designed based on different working status of the actuator and power source and it is realizable to accumulate energy from road vibration and supply energy to the actuator by switching corresponding electric circuits. To apply the self-powered suspension criterion and energy regeneration implementation scheme, an active suspension system is designed with a constrained H∞ controller and calculation results indicate that it has the capability to be self-powered. Simulation results show that the performances of the self-powered active suspension are nearly the same as those of the active suspension with an external energy source and can achieve energy regeneration at the same time.

A high frequency high power IGBT inverter drive for 45 HP/16,000 rpm brushless homopolar inductor motor

Energy Technology Data Exchange (ETDEWEB)

He, J.; Lin, F. [Stone Safety Corp., Fountain Inn, SC (United States)

1995-12-31

A microprocessor-based ultra-high speed brushless homopolar inductor motor drive system (HiDrive) with no gearing and using a high frequency IGBT inverter switching at 32 kHz is described and discussed in this paper. The homopolar motor features a solid steel rotor without magnets, windings, or laminations, which allows the motor to be operated at very high speed. The HiDrive system achieves 16,000 RPM, 45 Hp continuously. The drive system discussed in this paper can be used to replace conventional motors and speed increasing gear boxes in very high speed industrial applications such as centrifuges, compressors, blowers, pumps, and machine tool spindles. The HiDrive system discussed in this paper is used to drive a compressor for nuclear power application. In this paper, the detailed descriptions of the motor construction, equivalent circuit, operation and control principle are offered. The IGBT inverter drive system design and controls including motor speed sensing, load angle control, synchronization, brake control, power device switchings, and thermal issues are addressed. The simulation results various test results, and the typical application examples of the high speed drives are also presented in this paper.

A high frequency high power IGBT inverter drive for 45 HP/16,000 rpm brushless homopolar inductor motor

International Nuclear Information System (INIS)

He, J.; Lin, F.

1995-01-01

A microprocessor-based ultra-high speed brushless homopolar inductor motor drive system (HiDrive) with no gearing and using a high frequency IGBT inverter switching at 32 kHz is described and discussed in this paper. The homopolar motor features a solid steel rotor without magnets, windings, or laminations, which allows the motor to be operated at very high speed. The HiDrive system achieves 16,000 RPM, 45 Hp continuously. The drive system discussed in this paper can be used to replace conventional motors and speed increasing gear boxes in very high speed industrial applications such as centrifuges, compressors, blowers, pumps, and machine tool spindles. The HiDrive system discussed in this paper is used to drive a compressor for nuclear power application. In this paper, the detailed descriptions of the motor construction, equivalent circuit, operation and control principle are offered. The IGBT inverter drive system design and controls including motor speed sensing, load angle control, synchronization, brake control, power device switchings, and thermal issues are addressed. The simulation results various test results, and the typical application examples of the high speed drives are also presented in this paper

Integrated power-saving motor for power-demands of less than one kilowatt; Integral-Sparmotor im Leistungsbereich < 1 kW

Energy Technology Data Exchange (ETDEWEB)

Lindegger, M.; Kreuzer, H.H.; Lischer, G.

2005-10-15

This annual report for the Swiss Federal Office of Energy (SFOE) takes a look at the results of the second phase of a project concerning the development of integrated energy-saving electrical motors in the power range less than one kilowatt. The search for industrial partners is commented on and the publishing of an initial functional prototype on the Internet is mentioned. Participation at various fairs and the publication of articles in the technical press are mentioned. Further work on the motor is described, as is development work done on the drive electronics and the associated software. Further work planned is described.

Transient and steady-state tests of the space power research engine with resistive and motor loads

Science.gov (United States)

Rauch, Jeffrey S.; Kankam, M. David

1995-01-01

The NASA Lewis Research Center (LeRC) has been testing free-piston Stirling engine/linear alternators (FPSE/LA) to develop advanced power convertors for space-based electrical power generation. Tests reported herein were performed to evaluate the interaction and transient behavior of FPSE/LA-based power systems with typical user loads. Both resistive and small induction motor loads were tested with the space power research engine (SPRE) power system. Tests showed that the control system could maintain constant long term voltage and stable periodic operation over a large range of engine operating parameters and loads. Modest resistive load changes were shown to cause relatively large voltage and, therefore, piston and displacer amplitude excursions. Starting a typical small induction motor was shown to cause large and, in some cases, deleterious voltage transients. The tests identified the need for more effective controls, if FPSE/LAs are to be used for stand-alone power systems. The tests also generated a large body of transient dynamic data useful for analysis code validation.

Transient and Steady-state Tests of the Space Power Research Engine with Resistive and Motor Loads

Science.gov (United States)

Rauch, Jeffrey S.; Kankam, M. David

1995-01-01

The NASA Lewis Research Center (LeRC) has been testing free-piston Stirling engine/linear alternators (FPSE/LA) to develop advanced power convertors for space-based electrical power generation. Tests reported herein were performed to evaluate the interaction and transient behavior of FPSE/LA-based power systems with typical user loads. Both resistive and small induction motor loads were tested with the space power research engine (SPRE) power system. Tests showed that the control system could maintain constant long term voltage and stable periodic operation over a large range of engine operating parameters and loads. Modest resistive load changes were shown to cause relatively large voltage and, therefore, piston and displacer amplitude excursions. Starting a typical small induction motor was shown to cause large and, in some cases, deleterious voltage transients. The tests identified the need for more effective controls, if FPSE/LAs are to be used for stand-alone power systems. The tests also generated a large body of transient dynamic data useful for analysis code validation.

Task-specificity of unilateral anodal and dual-M1 tDCS effects on motor learning.

Science.gov (United States)

Karok, Sophia; Fletcher, David; Witney, Alice G

2017-01-08

Task-specific effects of transcranial direct current stimulation (tDCS) on motor learning were investigated in 30 healthy participants. In a sham-controlled, mixed design, participants trained on 3 different motor tasks (Purdue Pegboard Test, Visuomotor Grip Force Tracking Task and Visuomotor Wrist Rotation Speed Control Task) over 3 consecutive days while receiving either unilateral anodal over the right primary motor cortex (M1), dual-M1 or sham stimulation. Retention sessions were administered 7 and 28 days after the end of training. In the Purdue Pegboard Test, both anodal and dual-M1 stimulation reduced average completion time approximately equally, an improvement driven by online learning effects and maintained for about 1 week. The Visuomotor Grip Force Tracking Task and the Visuomotor Wrist Rotation Speed Control Task were associated with an advantage of dual-M1 tDCS in consolidation processes both between training sessions and when testing at long-term retention; both were maintained for at least 1 month. This study demonstrates that M1-tDCS enhances and sustains motor learning with different electrode montages. Stimulation-induced effects emerged at different learning phases across the tasks, which strongly suggests that the influence of tDCS on motor learning is dynamic with respect to the functional recruitment of the distributed motor system at the time of stimulation. Divergent findings regarding M1-tDCS effects on motor learning may partially be ascribed to task-specific consequences and the effects of offline consolidation. Copyright © 2016 Elsevier Ltd. All rights reserved.

FY2010 Annual Progress Report for Advanced Power Electronics and Electric Motors

Energy Technology Data Exchange (ETDEWEB)

Rogers, Susan A. [Office of Energy Efficiency and Renewable Energy (EERE), Washington, DC (United States)

2011-01-01

The Advanced Power Electronics and Electric Machines (APEEM) subprogram within the Vehicle Technologies Program provides support and guidance for many cutting-edge automotive technologies now under development. Research is focused on developing revolutionary new power electronics (PE) and electric motor technologies that will leapfrog current on-the-road technologies. The research and development (R&D) is also aimed at achieving a greater understanding of and improvements in the way the various new components of tomorrow’s automobiles will function as a unified system to improve fuel efficiency.

Direct Lineage Reprogramming Reveals Disease-Specific Phenotypes of Motor Neurons from Human ALS Patients

Directory of Open Access Journals (Sweden)

Meng-Lu Liu

2016-01-01

Full Text Available Subtype-specific neurons obtained from adult humans will be critical to modeling neurodegenerative diseases, such as amyotrophic lateral sclerosis (ALS. Here, we show that adult human skin fibroblasts can be directly and efficiently converted into highly pure motor neurons without passing through an induced pluripotent stem cell stage. These adult human induced motor neurons (hiMNs exhibit the cytological and electrophysiological features of spinal motor neurons and form functional neuromuscular junctions (NMJs with skeletal muscles. Importantly, hiMNs converted from ALS patient fibroblasts show disease-specific degeneration manifested through poor survival, soma shrinkage, hypoactivity, and an inability to form NMJs. A chemical screen revealed that the degenerative features of ALS hiMNs can be remarkably rescued by the small molecule kenpaullone. Taken together, our results define a direct and efficient strategy to obtain disease-relevant neuronal subtypes from adult human patients and reveal their promising value in disease modeling and drug identification.

Changes of motor-cortical oscillations associated with motor learning.

Science.gov (United States)

Pollok, B; Latz, D; Krause, V; Butz, M; Schnitzler, A

2014-09-05

Motor learning results from practice but also between practice sessions. After skill acquisition early consolidation results in less interference with other motor tasks and even improved performance of the newly learned skill. A specific significance of the primary motor cortex (M1) for early consolidation has been suggested. Since synchronized oscillatory activity is assumed to facilitate neuronal plasticity, we here investigate alterations of motor-cortical oscillations by means of event-related desynchronization (ERD) at alpha (8-12 Hz) and beta (13-30 Hz) frequencies in healthy humans. Neuromagnetic activity was recorded using a 306-channel whole-head magnetoencephalography (MEG) system. ERD was investigated in 15 subjects during training on a serial reaction time task and 10 min after initial training. The data were compared with performance during a randomly varying sequence serving as control condition. The data reveal a stepwise decline of alpha-band ERD associated with faster reaction times replicating previous findings. The amount of beta-band suppression was significantly correlated with reduction of reaction times. While changes of alpha power have been related to lower cognitive control after initial skill acquisition, the present data suggest that the amount of beta suppression represents a neurophysiological marker of early cortical reorganization associated with motor learning. Copyright © 2014 IBRO. Published by Elsevier Ltd. All rights reserved.

Survival motor neuron protein in motor neurons determines synaptic integrity in spinal muscular atrophy.

Science.gov (United States)

Martinez, Tara L; Kong, Lingling; Wang, Xueyong; Osborne, Melissa A; Crowder, Melissa E; Van Meerbeke, James P; Xu, Xixi; Davis, Crystal; Wooley, Joe; Goldhamer, David J; Lutz, Cathleen M; Rich, Mark M; Sumner, Charlotte J

2012-06-20

The inherited motor neuron disease spinal muscular atrophy (SMA) is caused by deficient expression of survival motor neuron (SMN) protein and results in severe muscle weakness. In SMA mice, synaptic dysfunction of both neuromuscular junctions (NMJs) and central sensorimotor synapses precedes motor neuron cell death. To address whether this synaptic dysfunction is due to SMN deficiency in motor neurons, muscle, or both, we generated three lines of conditional SMA mice with tissue-specific increases in SMN expression. All three lines of mice showed increased survival, weights, and improved motor behavior. While increased SMN expression in motor neurons prevented synaptic dysfunction at the NMJ and restored motor neuron somal synapses, increased SMN expression in muscle did not affect synaptic function although it did improve myofiber size. Together these data indicate that both peripheral and central synaptic integrity are dependent on motor neurons in SMA, but SMN may have variable roles in the maintenance of these different synapses. At the NMJ, it functions at the presynaptic terminal in a cell-autonomous fashion, but may be necessary for retrograde trophic signaling to presynaptic inputs onto motor neurons. Importantly, SMN also appears to function in muscle growth and/or maintenance independent of motor neurons. Our data suggest that SMN plays distinct roles in muscle, NMJs, and motor neuron somal synapses and that restored function of SMN at all three sites will be necessary for full recovery of muscle power.

Nuclear safety review for qualification of class 1E motor inside containment for nuclear power stations

International Nuclear Information System (INIS)

Li Shixin; Wu Qi; Zhang Yunbo; Wu Caixia

2013-01-01

In nuclear power plants with pressurized water reactors, the review for class 1E motor inside containment qualification process and documents is an important aspect of nuclear safety equipment review, and the reviewers should make evaluations for the qualification test results in terms of the compliance with standard and regulation, and the consistency with inside containment environment. Firstly, this paper introduces the qualification test of class 1E motor inside containment for nuclear power generating stations, such as aging test and design-basis-event test. Second, there is a discussion about typical problems of review. At last, comparison of IEEE334 with RCC-E is conducted and explored. (authors)

Application of superconductors to motors, generators, and transmission lines

International Nuclear Information System (INIS)

Kirtley, J.L.

1989-01-01

Superconductors are of interest to the designers of electric power equipment because they can carry current without loss, currents that are large enough to make very intense magnetic fields. This means that superconductors, used in suitable applications, can make electric power equipment smaller, lighter, more efficient, and perhaps with better dynamic response. Two specific applications are considered here: electric machinery (motors and generators) and transmission lines. The so-called high-T c superconductors will have beneficial impact on motors, generators, and transmission lines only if conductors with sufficient mechanical properties and current-carrying capabilities can be developed

Psychomotor and Motor Speed in Power Athletes Self-Administering Testosterone and Anabolic Steroids.

Science.gov (United States)

Era, Pertti; And Others

1988-01-01

Self-administered testosterone and anabolic steroids resulted in insignificant improvement in psychomotor and motor speed tests of power athletes. This study is part of a larger study on the effects of such drugs on endocrinology, metabolism and neuromuscular functions. Methodolgy and results are discussed. (Author/JL)

Power conditioning for large dc motors for space flight applications

Science.gov (United States)

Veatch, Martin S.; Anderson, Paul M.; Eason, Douglas J.; Landis, David M.

1988-01-01

The design and performance of a prototype power-conditioning system for use with large brushless dc motors on NASA space missions are discussed in detail and illustrated with extensive diagrams, drawings, and graphs. The 5-kW 8-phase parallel module evaluated here would be suitable for use in the Space Shuttle Orbiter cargo bay. A current-balancing magnetic assembly with low distributed inductance permits high-speed current switching from a low-voltage bus as well as current balancing between parallel MOSFETs.

Motor-operated gearbox efficiency

International Nuclear Information System (INIS)

DeWall, K.G.; Watkins, J.C.; Bramwell, D.; Weidenhamer, G.H.

1996-01-01

Researchers at the Idaho National Engineering Laboratory recently conducted tests investigating the operating efficiency of the power train (gearbox) in motor-operators typically used in nuclear power plants to power motor-operated valves. Actual efficiency ratios were determined from in-line measurements of electric motor torque (input to the operator gearbox) and valve stem torque (output from the gearbox) while the operators were subjected to gradually increasing loads until the electric motor stalled. The testing included parametric studies under reduced voltage and elevated temperature conditions. As part of the analysis of the results, the authors compared efficiency values determined from testing to the values published by the operator manufacturer and typically used by the industry in calculations for estimating motor-operator capabilities. The operators they tested under load ran at efficiencies lower than the running efficiency (typically 50%) published by the operator manufacturer

Motor-operated gearbox efficiency

Energy Technology Data Exchange (ETDEWEB)

DeWall, K.G.; Watkins, J.C.; Bramwell, D. [Idaho National Engineering Lab., Idaho Falls, ID (United States); Weidenhamer, G.H.

1996-12-01

Researchers at the Idaho National Engineering Laboratory recently conducted tests investigating the operating efficiency of the power train (gearbox) in motor-operators typically used in nuclear power plants to power motor-operated valves. Actual efficiency ratios were determined from in-line measurements of electric motor torque (input to the operator gearbox) and valve stem torque (output from the gearbox) while the operators were subjected to gradually increasing loads until the electric motor stalled. The testing included parametric studies under reduced voltage and elevated temperature conditions. As part of the analysis of the results, the authors compared efficiency values determined from testing to the values published by the operator manufacturer and typically used by the industry in calculations for estimating motor-operator capabilities. The operators they tested under load ran at efficiencies lower than the running efficiency (typically 50%) published by the operator manufacturer.

Motor-operator gearbox efficiency

International Nuclear Information System (INIS)

DeWall, K.G.; Watkins, J.C.; Bramwell, D.

1996-01-01

Researchers at the Idaho National Engineering Laboratory recently conducted tests investigating the operating efficiency of the power train (gearbox) in motor-operators typically used in nuclear power plants to power motor-operated valves. Actual efficiency ratios were determined from in-line measurements of electric motor torque (input to the operator gearbox) and valve stem torque (output from the gearbox) while the operators were subjected to gradually increasing loads until the electric motor stalled. The testing included parametric studies under reduced voltage and elevated temperature conditions. As part of the analysis of the results, we compared efficiency values determined from testing to the values published by the operator manufacturer and typically used by the industry in calculations for estimating motor-operator capabilities. The operators we tested under load ran at efficiencies lower than the running efficiency (typically 50%) published by the operator manufacturer

Priming of disability and elderly stereotype in motor performance: similar or specific effects?

Science.gov (United States)

Ginsberg, Frederik; Rohmer, Odile; Louvet, Eva

2012-04-01

In three experimental studies, the effects of priming participants with the disability stereotype were investigated with respect to their subsequent motor performance. Also explored were effects of activating two similar stereotypes, persons with a disability and elderly people. In Study 1, participants were primed with the disability stereotype versus with a neutral prime, and then asked to perform on a motor coordination task. In Studies 2 and 3, a third condition was introduced: priming participants with the elderly stereotype. Results indicated that priming participants with the disability stereotype altered their motor performance: they showed decreased manual dexterity and performed slower than the non-primed participants. Priming with the elderly stereotype decreased only performance speed. These findings underline that prime-to-behavior effects may depend on activation of specific stereotype content.

76 FR 11415 - Federal Motor Vehicle Safety Standards; Power-Operated Window, Partition, and Roof Panel Systems

Science.gov (United States)

2011-03-02

... [Docket No. NHTSA-2011-0027] RIN 2127-AK52 Federal Motor Vehicle Safety Standards; Power-Operated Window, Partition, and Roof Panel Systems AGENCY: National Highway Traffic Safety Administration (NHTSA), Department... automatic reversal systems (ARS) for power windows and to make a final decision. The agency has decided not...

Motor-operated valve (MOV) actuator motor and gearbox testing

International Nuclear Information System (INIS)

DeWall, K.; Watkins, J.C.; Bramwell, D.

1997-07-01

Researchers at the Idaho National Engineering and Environmental Laboratory tested the performance of electric motors and actuator gearboxes typical of the equipment installed on motor-operated valves used in nuclear power plants. Using a test stand that simulates valve closure loads against flow and pressure, the authors tested five electric motors (four ac and one dc) and three gearboxes at conditions a motor might experience in a power plant, including such off-normal conditions as operation at high temperature and reduced voltage. They also monitored the efficiency of the actuator gearbox. All five motors operated at or above their rated starting torque during tests at normal voltages and temperatures. For all five motors, actual torque losses due to voltage degradation were greater than the losses calculated by methods typically used for predicting motor torque at degraded voltage conditions. For the dc motor the actual torque losses due to elevated operating temperatures were greater than the losses calculated by the typical predictive method. The actual efficiencies of the actuator gearboxes were generally lower than the running efficiencies published by the manufacturer and were generally nearer the published pull-out efficiencies. Operation of the gearbox at elevated temperature did not affect the operating efficiency

The selection of flying roller as an effort to increase the power of scooter-matic as the main power of centrifugal pump for fire fighter motor cycle

Science.gov (United States)

Hadi Sutrisno, Himawan

2018-03-01

In densely populated settlements, fires often occur and cause losses. In some instances, the process of the occurrence of fires takes place so quickly that to reduce and avoid the occurrence of a fire disaster effort is required in accordance with the existing environmental condition. Fire fighter motorcycle by using motorcycle scooter-matic is considered suitable as one alternative to combating fire hazard in densely populated residential settlements. The use of motorcycle engines as the driving force of the pump often leads to unstable and not optimum power. Thus, the water spray on the centrifugal pump also becomes not maximum. To increase the engine power at scooter-matic engine idle rotation (700-2000 rpm), then the flying roller replacement with certain mass weight becomes an option. By selecting a 10 to 14 gram flying roller mass, the power analysis using a dynotest engine produces several variations. Of the calculation, the mass of a 14 gram flying roller provides a significant increase in motor power on the upper rotation. Meanwhile, on the lower power rotation using a flying roller with a mass of 10 grams provides an increase in power compared to a standard flying roller on a scooter matic motor engine. As a reference to the use of scooter-matic motor power as the pump power, the result of use of the flying roller with a mass of 10 grams becomes the best option.

Specific Needs of Learning Support pupils with sensory and motor disabilities

Directory of Open Access Journals (Sweden)

Diego Luque Parra

2013-12-01

Full Text Available This paper aims to make an approach to the study of specific educational needs in children with disabilities. After an introduction to some conceptual and defining aspects, a needs analysis focus on children with sensorial and motor disabilities has taken place. Based on this one, general elements for educational response have been suggested. Finally, a conclusion and reflection that has been provided through the integration of the mentioned analysis, on both psychological intervention and guidance action, based on a perspective that addressed diversity from specific educational support needy children.

Fuel-Cell-Powered Electric Motor Drive Analyzed for a Large Airplane

Science.gov (United States)

Brown, Gerald V.; Choi, Benjamin B.

2005-01-01

Because of its high efficiency, fuel cell technology may be used to launch a new generation of more-electric aeropropulsion and power systems for future aircraft. Electric-motor-driven airplanes using fuel-cell powerplants would be beneficial to the environment because of fuel savings, low noise, and zero carbon-dioxide emissions. In spite of the fuel cell s efficiency benefit, to produce the same shaft drive power, a fuel cell- powered electric-drive system must be definitely heavier than a turbine-drive system. However, the fuel-cell system s overall efficiency from fuel-to-shaft power is higher than for a turbine-drive system. This means that the fuel consumption rate could be lower than for a conventional system. For heavier, fuel-laden planes for longer flights, we might achieve substantial fuel savings. In the airplane industry, in fact, an efficiency gain of even a few percentage points can make a major economic difference in operating costs.

Single-Phase Hybrid Switched Reluctance Motor for Low-Power Low-Cost Applications

DEFF Research Database (Denmark)

Lu, Kaiyuan; Rasmussen, Peter Omand; Jakobsen, Uffe

2011-01-01

This paper presents a new single-phase, Hybrid Switched Reluctance (HSR) motor for low-cost, low-power, pump or fan drive systems. Its single-phase configuration allows use of a simple converter to reduce the system cost. Cheap ferrite magnets are used and arranged in a special flux concentration...... manner to increase effectively the torque density and efficiency of this machine. The efficiency of this machine is comparable to the efficiency of a traditional permanent magnet machine in the similar power range. The cogging torque, due to the existence of the permanent magnetic field, is beneficially...

Piezoelectric/magnetostrictive resonant inchworm motor

Science.gov (United States)

Miesner, John E.; Teter, Joseph P.

1994-05-01

Magnetostrictive and piezoelectric materials were used to create a linear motor operating on the inchworm principle. This motor operates at an electrical resonance, switching power internally between inductive and capacitive components. Magnetic coils surrounding the two Terfenol-D rods which drive the inchworm's center expanding element form the inductive component. Piezoelectric stacks that control the end clamping action are the capacitive components. The normal electrical phase relationship between these components provides natural drive timing for the inchworm. The motor direction can be easily reversed by changing the magnetic bias on the Terfenol. A prototype motor was built that achieved a stall load of 26 lb and no-load speed of 1 inch/sec vs the design of 30 lb and 1.3 inch/sec. A new type of power supply that switches power from a dc source was built for the motor. This power supply uses a small number of components to exactly supply the energy used in each inchworm cycle. It tracks the motor circuit resonance and is not affected by frequency shifts.

Motor control for a brushless DC motor

Science.gov (United States)

Peterson, William J. (Inventor); Faulkner, Dennis T. (Inventor)

1985-01-01

This invention relates to a motor control system for a brushless DC motor having an inverter responsively coupled to the motor control system and in power transmitting relationship to the motor. The motor control system includes a motor rotor speed detecting unit that provides a pulsed waveform signal proportional to rotor speed. This pulsed waveform signal is delivered to the inverter to thereby cause an inverter fundamental current waveform output to the motor to be switched at a rate proportional to said rotor speed. In addition, the fundamental current waveform is also pulse width modulated at a rate proportional to the rotor speed. A fundamental current waveform phase advance circuit is controllingly coupled to the inverter. The phase advance circuit is coupled to receive the pulsed waveform signal from the motor rotor speed detecting unit and phase advance the pulsed waveform signal as a predetermined function of motor speed to thereby cause the fundamental current waveform to be advanced and thereby compensate for fundamental current waveform lag due to motor winding reactance which allows the motor to operate at higher speeds than the motor is rated while providing optimal torque and therefore increased efficiency.

Efficiency Characteristics of Low Power Hybrid Switched Reluctance Motor

DEFF Research Database (Denmark)

Jakobsen, Uffe; Ahn, Jin-Woo

2009-01-01

Switched reluctance motors (SRM) are usually considered inferior in terms of efficiency as compared to permanent magnet synchronous motors (PMSM) and brushless DC-motors (BLDC), but less costly. This article presents a test of a 70W hybrid switched reluctance motor (HSRM), that archieves a peak...... efficiency for the motor drive of more than 74%, and an efficiency for the motor of almost 80%....

Experiments with a DC Motor

Science.gov (United States)

Kraftmakher, Yaakov

2010-01-01

Experiments with an electric motor provide good opportunity to demonstrate some basic laws of electricity and magnetism. The aim of the experiments with a low-power dc motor is to show how the motor approaches its steady rotation and how its torque, mechanical power and efficiency depend on the rotation velocity. The tight relationship between the…

Grey matter volume loss is associated with specific clinical motor signs in Huntington's disease.

Science.gov (United States)

Coppen, Emma M; Jacobs, Milou; van den Berg-Huysmans, Annette A; van der Grond, Jeroen; Roos, Raymund A C

2018-01-01

Motor disturbances are clinical hallmarks of Huntington's disease (HD) and involve chorea, dystonia, hypokinesia and visuomotor dysfunction. Investigating the association between specific motor signs and different regional volumes is important to understand the heterogeneity of HD. To investigate the motor phenotype of HD and associations with subcortical and cortical grey matter volume loss. Structural T1-weighted MRI scans of 79 HD patients and 30 healthy controls were used to calculate volumes of seven subcortical structures including the nucleus accumbens, hippocampus, thalamus, caudate nucleus, putamen, pallidum and amygdala. Multiple linear regression analyses, corrected for age, gender, CAG, MRI scan protocol and normalized brain volume, were performed to assess the relationship between subcortical volumes and different motor subdomains (i.e. eye movements, chorea, dystonia, hypokinesia/rigidity and gait/balance). Voxel-based morphometry analysis was used to investigate the relationship between cortical volume changes and motor signs. Subcortical volume loss of the accumbens nucleus, caudate nucleus, putamen, and pallidum were associated with higher chorea scores. No other subcortical region was significantly associated with motor symptoms after correction for multiple comparisons. Voxel-based cortical grey matter volume reductions in occipital regions were related with an increase in eye movement scores. In HD, chorea is mainly associated with subcortical volume loss, while eye movements are more related to cortical volume loss. Both subcortical and cortical degeneration has an impact on motor impairment in HD. This implies that there is a widespread contribution of different brain regions resulting in the clinical motor presentation seen in HD patients. Copyright © 2017 Elsevier Ltd. All rights reserved.

Improving motor skills of children in secondary school by using means specific to football game

Directory of Open Access Journals (Sweden)

Sorin BRÎNDESCU

2017-03-01

Full Text Available Football, by tradition is a popular sport, a mass sport, both for those who 32ractici it and for the audience. The game of football becomes the only sport that can be 32racticin by everybody. Its simplicity is expressed by a regulation set which includes few basic rules, logical rules and relatively easy to understand. Football is a game that develops basic motor skills: speed, strength, stamina, specific skills. Use of means specific to the football game in physical education classes at the secondary level aims to improve motor skills and streamline the educational process. The means specific to the football game that are used are simple, clear, suitable for both girls and boys, in order to achieve outstanding results in physical education classes

Anthropometric, physical and motor performance determinants of ...

African Journals Online (AJOL)

The most talented subjects (N = 39) were selected from 66 boys by means of a Talent Search testing protocol and then subjected to a sport specific test battery consisting of five anthropometric and 16 physical and motor variables. The results indicated that mean anaerobic power output, acceleration, body mass, reaction ...

DIAGNOSING OF BASIC AND SPECIFIC MOTORIC CAPABILITIES AT THE YOUTH OF THE BASKETBALL SCHOOL

OpenAIRE

Florian Miftari; Hasim Rushiti; Bahri Gjinovci

2015-01-01

In general the problematic of diagnosing basic and specific motor movement information of the basketball game in found in the works of a considerable number of world authors. In this work a youth population of an age group between 13-14 years old will be treated. The total number of participants is defined to an amount of 100 of young basketball players, members of two different basketball academies. In this experiment, the subjects will conduct tests in 5 basic motor skills variables such as...

The development and testing of a linear induction motor being fed from the source with limited electric power

Science.gov (United States)

Tiunov, V. V.

2018-02-01

The report provides results of the research related to the tubular linear induction motors’ application. The motors’ design features, a calculation model, a description of test specimens for mining and electric power industry are introduced. The most attention is given to the single-phase motors for high voltage switches drives with the usage of inexpensive standard single-phase transformers for motors’ power supply. The method of the motor’s parameters determination, when the motor is being fed from the transformer, working in the overload mode, was described, and the results of it practical usage were good enough for the engineering practice.

Feasibility study of electric motors constructed with high temperature superconducting materials

International Nuclear Information System (INIS)

Jordan, H.E.

1989-01-01

The potential application of high temperature superconducting (HTSC) materials to electric motors is discussed. The specific application area of motors in electric power generating stations has been selected and a feasible study has been initiated on the use of HTSC materials in the design of motors for this application. A progress report on this feasibility study is presented. Technical challenges in both the development of HTSC wire and the design of a motor to utilize this wire are discussed. Finally, the results of design calculations comparing a superconducting motor with one of conventional design are presented assuming that success can be achieved in overcoming the technical problems which must be resolved to produce a high performance HTSC wire

Motor unit potential morphology differences in individuals with non-specific arm pain and lateral epicondylitis

Directory of Open Access Journals (Sweden)

McLean Linda

2008-12-01

Full Text Available Abstract Background The pathophysiology of non-specific arm pain (NSAP is unclear and the diagnosis is made by excluding other specific upper limb pathologies, such as lateral epicondylitis or cervical radiculopathy. The purpose of this study was to determine: (i if the quantitative parameters related to motor unit potential morphology and/or motor unit firing patterns derived from electromyographic (EMG signals detected from an affected muscle of patients with NSAP are different from those detected in the same muscle of individuals with lateral epicondylitis (LE and/or control subjects and (ii if the quantitative EMG parameters suggest that the underlying pathophysiology in NSAP is either myopathic or neuropathic in nature. Methods Sixteen subjects with NSAP, 11 subjects with LE, eight subjects deemed to be at-risk for developing a repetitive strain injury, and 37 control subjects participated. A quantitative electromyography evaluation was completed using decomposition-based quantitative electromyography (DQEMG. Needle- and surface-detected EMG signals were collected during low-level isometric contractions of the extensor carpi radialis brevis (ECRB muscle. DQEMG was used to extract needle-detected motor unit potential trains (MUPTs, and needle-detected motor unit potential (MUP and surface detected motor unit potential (SMUP morphology and motor unit (MU firing rates were compared among the four groups using one-way analysis of variance (ANOVA. Post hoc analyses were performed using Tukey's pairwise comparisons. Results Significant group differences were found for all MUP variables and for MU firing rate (p p p p p Conclusion The size-related parameters suggest that the NSAP group had significantly smaller MUPs and SMUPs than the control and LE subjects. Smaller MUPs and SMUPs may be indicative of muscle fiber atrophy and/or loss. A prospective study is needed to confirm any causal relationship between smaller MUPs and SMUPs and NSAP as found

Mechanics of torque generation in the bacterial flagellar motor.

Science.gov (United States)

Mandadapu, Kranthi K; Nirody, Jasmine A; Berry, Richard M; Oster, George

2015-08-11

The bacterial flagellar motor (BFM) is responsible for driving bacterial locomotion and chemotaxis, fundamental processes in pathogenesis and biofilm formation. In the BFM, torque is generated at the interface between transmembrane proteins (stators) and a rotor. It is well established that the passage of ions down a transmembrane gradient through the stator complex provides the energy for torque generation. However, the physics involved in this energy conversion remain poorly understood. Here we propose a mechanically specific model for torque generation in the BFM. In particular, we identify roles for two fundamental forces involved in torque generation: electrostatic and steric. We propose that electrostatic forces serve to position the stator, whereas steric forces comprise the actual "power stroke." Specifically, we propose that ion-induced conformational changes about a proline "hinge" residue in a stator α-helix are directly responsible for generating the power stroke. Our model predictions fit well with recent experiments on a single-stator motor. The proposed model provides a mechanical explanation for several fundamental properties of the flagellar motor, including torque-speed and speed-ion motive force relationships, backstepping, variation in step sizes, and the effects of key mutations in the stator.

Morphological and motor characteristics of Croatian first league female football players.

Science.gov (United States)

Jelaska, Petra Mandić; Katić, Ratko; Jelaska, Igor

2013-05-01

The aim of this study was to determine the structure of morphological and motor characteristics of Croatian first league female football players and their impact on the estimated quality of the players. According to the goal of the research, a sample consisted of 70 Croatian first league female football players. Participants were measured in 18 tests for assessing morphological characteristics, a set of 12 basic motor abilities tests and a set of 7 tests for assessing football-specific motor abilities. Exploratory factor analysis strategy was applied separately to all measured tests: morphological, basic motor abilities and football specific motor abilities. Factor analysis of morphological tests has shown existence of 3 significant latent dimensions that explain 64% of the total variability. Factors are defined as transverse dimensionality of the skeleton and voluminosity (35%), subcutaneous fat tissue (16%) and longitudinal dimensionality of the skeleton (13%). In the area of basic motor abilities, four factors were extracted. The first factor is responsible for the integration of agility and explosive power of legs, i.e. a factor of movement regulation (agility/lower body explosiveness) (23%), the second one defines muscle tone regulation (15%), the third one defines the frequency of leg movements (12%), while the fourth one is recognized as responsible for the manifestation of basic strength, particularly of basic core strength (19%). Two factors were isolated in the space of football-specific motor abilities: football-specific efficiency (53%) and situational football coordination (27%). Furthermore, by use of factor analysis on extracted latent dimensions (morphological, basic and football specific motor abilities) two higher order factors (explaining 87% of common variability) were extracted. They were named morphological-motor factor (54%) and football-specific motor abilities factor (33%). It is assumed that two extracted higher-order factors fully

A catalytic oligomeric motor that walks along a filament track

Energy Technology Data Exchange (ETDEWEB)

Huang, Mu-Jie, E-mail: mjhuang@chem.utoronto.ca; Kapral, Raymond, E-mail: rkapral@chem.utoronto.ca [Chemical Physics Theory Group, Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6 (Canada)

2015-06-28

Most biological motors in the cell execute chemically powered conformational changes as they walk on biopolymer filaments in order to carry out directed transport functions. Synthetic motors that operate in a similar manner are being studied since they have the potential to perform similar tasks in a variety of applications. In this paper, a synthetic nanomotor that moves along a filament track, without invoking motor conformational changes, is constructed and its properties are studied in detail. The motor is an oligomer comprising three linked beads with specific binding properties. The filament track is a stiff polymer chain, also described by a linear chain of linked coarse-grained molecular groups modeled as beads. Reactions on the filament that are catalyzed by a motor bead and use fuel in the environment, in conjunction within the binding affinities of the motor beads to the filament beads, lead to directed motion. The system operates out of equilibrium due to the state of the filament and supply of fuel. The motor, filament, and surrounding medium are all described at microscopic level that permits a full analysis of the motor motion. A stochastic model that captures the main trends seen in the simulations is also presented. The results of this study point to some of the key features that could be used to construct nanomotors that undergo biased walks powered by chemical reactions on filaments.

A catalytic oligomeric motor that walks along a filament track

Science.gov (United States)

Huang, Mu-Jie; Kapral, Raymond

2015-06-01

Most biological motors in the cell execute chemically powered conformational changes as they walk on biopolymer filaments in order to carry out directed transport functions. Synthetic motors that operate in a similar manner are being studied since they have the potential to perform similar tasks in a variety of applications. In this paper, a synthetic nanomotor that moves along a filament track, without invoking motor conformational changes, is constructed and its properties are studied in detail. The motor is an oligomer comprising three linked beads with specific binding properties. The filament track is a stiff polymer chain, also described by a linear chain of linked coarse-grained molecular groups modeled as beads. Reactions on the filament that are catalyzed by a motor bead and use fuel in the environment, in conjunction within the binding affinities of the motor beads to the filament beads, lead to directed motion. The system operates out of equilibrium due to the state of the filament and supply of fuel. The motor, filament, and surrounding medium are all described at microscopic level that permits a full analysis of the motor motion. A stochastic model that captures the main trends seen in the simulations is also presented. The results of this study point to some of the key features that could be used to construct nanomotors that undergo biased walks powered by chemical reactions on filaments.

A catalytic oligomeric motor that walks along a filament track

International Nuclear Information System (INIS)

Huang, Mu-Jie; Kapral, Raymond

2015-01-01

Most biological motors in the cell execute chemically powered conformational changes as they walk on biopolymer filaments in order to carry out directed transport functions. Synthetic motors that operate in a similar manner are being studied since they have the potential to perform similar tasks in a variety of applications. In this paper, a synthetic nanomotor that moves along a filament track, without invoking motor conformational changes, is constructed and its properties are studied in detail. The motor is an oligomer comprising three linked beads with specific binding properties. The filament track is a stiff polymer chain, also described by a linear chain of linked coarse-grained molecular groups modeled as beads. Reactions on the filament that are catalyzed by a motor bead and use fuel in the environment, in conjunction within the binding affinities of the motor beads to the filament beads, lead to directed motion. The system operates out of equilibrium due to the state of the filament and supply of fuel. The motor, filament, and surrounding medium are all described at microscopic level that permits a full analysis of the motor motion. A stochastic model that captures the main trends seen in the simulations is also presented. The results of this study point to some of the key features that could be used to construct nanomotors that undergo biased walks powered by chemical reactions on filaments

Flywheel for a 167 MVA surge power motor-generator set

International Nuclear Information System (INIS)

Mertens, H.

1975-01-01

Flywheels to be subjected to major speed fluctuations are designed on the basis of both the usual strength analysis and fracture mechanics considerations, and the testing and operating instructions have to allow for this. Appropriate test units are used to determine the fracture toughness of the material. Residual stresses are measured and extensive ultrasonic and magnetic particle tests performed to enable the permissible number of stress cycles to be predicted. The article deals with these problems by reference to the flywheel of a 167 MVA surge power motor-generator set for the Max Planck Insitute for Plasma Physics in Garching. (orig.) [de

FY2014 Oak Ridge National Laboratory Annual Progress Report for the Power Electronics and Electric Motors Program

Energy Technology Data Exchange (ETDEWEB)

Ozpineci, Burak [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

2014-11-01

The US Department of Energy (DOE) announced in May 2011 a new cooperative research effort comprising DOE, the US Council for Automotive Research (composed of automakers Ford Motor Company, General Motors Company, and Chrysler Group), Tesla Motors, and representatives of the electric utility and petroleum industries. Known as U.S. DRIVE (Driving Research and Innovation for Vehicle efficiency and Energy sustainability), it represents DOE’s commitment to developing public–private partnerships to fund high-risk–high-reward research into advanced automotive technologies. The new partnership replaces and builds upon the partnership known as FreedomCAR (derived from “Freedom” and “Cooperative Automotive Research”) that ran from 2002 through 2010 and the Partnership for a New Generation of Vehicles initiative that ran from 1993 through 2001. Oak Ridge National Laboratory’s (ORNL’s) Advanced Power Electronics and Electric Motors (APEEM) subprogram within the DOE Vehicle Technologies Office (VTO) provides support and guidance for many cutting-edge automotive technologies now under development. Research is focused on developing revolutionary new power electronics (PE), electric motor, and traction drive system (TDS) technologies that will leapfrog current on-the-road technologies, leading to lower cost and better efficiency in transforming battery energy to useful work. The research and development (R&D) is also aimed at achieving a greater understanding of and improvements in the way the various new components of tomorrow’s automobiles will function as a unified system to improve fuel efficiency through research in more efficient TDSs.

Introduction to electrical power and power electronics

CERN Document Server

Patel, Mukund R

2012-01-01

Power Generation, Distribution, and Utilization AC Power Fundamentals Common Aspects of Power Equipments AC Generator AC and DC Motors Transformer Power Cable Power Distribution Fault Current Analysis System ProtectionEconomic Use of PowerElectrochemical BatteryPower Electronics and Motor Drives Power Electronics Devices DC-DC Converters AC-DC-AC Converters Variable-Frequency Drives Quality of Power Power Converter CoolingAppendixIndex

Modelling and Improvement of Thermal Cycling in Power Electronics for Motor Drive Applications

DEFF Research Database (Denmark)

Vernica, Ionut; Ma, Ke; Blaabjerg, Frede

2016-01-01

It is well known that the dynamical change of the thermal stress in the power devices is one of the major factors that have influences on the overall efficiency and reliability of power electronics. The main objective of this paper consists of identifying the main parameters that affect the thermal...... are identified during the acceleration and deceleration periods of the motor. The main causes for these adverse thermal cycles have been presented and, consequently, the influence of the deceleration slope, modulation technique and reactive current on the thermal cycles has been analyzed. Finally, the improved...

Advanced dc-Traction-Motor Control System

Science.gov (United States)

Vittone, O.

1985-01-01

Motor-control concept for battery-powered vehicles includes stateof-the-art power-transistor switching and separate excitation of motor windings in traction and regenerative braking. Switching transistors and other components of power-conditioning subsystem operate under control of computer that coordinates traction, braking, and protective functions.

Effects of practice schedule and task specificity on the adaptive process of motor learning.

Science.gov (United States)

Barros, João Augusto de Camargo; Tani, Go; Corrêa, Umberto Cesar

2017-10-01

This study investigated the effects of practice schedule and task specificity based on the perspective of adaptive process of motor learning. For this purpose, tasks with temporal and force control learning requirements were manipulated in experiments 1 and 2, respectively. Specifically, the task consisted of touching with the dominant hand the three sequential targets with specific movement time or force for each touch. Participants were children (N=120), both boys and girls, with an average age of 11.2years (SD=1.0). The design in both experiments involved four practice groups (constant, random, constant-random, and random-constant) and two phases (stabilisation and adaptation). The dependent variables included measures related to the task goal (accuracy and variability of error of the overall movement and force patterns) and movement pattern (macro- and microstructures). Results revealed a similar error of the overall patterns for all groups in both experiments and that they adapted themselves differently in terms of the macro- and microstructures of movement patterns. The study concludes that the effects of practice schedules on the adaptive process of motor learning were both general and specific to the task. That is, they were general to the task goal performance and specific regarding the movement pattern. Copyright © 2017 Elsevier B.V. All rights reserved.

Gender-Specific Peculiarities of Motor Preparedness of Children Aged 6-10

Directory of Open Access Journals (Sweden)

О. В. Іващенко

2017-03-01

Full Text Available The objective is to determine the gender-specific peculiarities of motor preparedness of children aged 6-10.  Materials and methods: the participants in the study were girls aged 6 (n = 36, aged 7 (n = 48, aged 8 (n = 57, aged 9 (n = 38, aged 10 (n = 46; boys aged 6 (n = 48, aged 7 (n = 45, aged 8 (n = 60, aged 9 (n = 47, aged 10 (n = 40. To achieve the tasks set, the study relied on the following research methods: analysis of scientific literature, pedagogical testing and methods of mathematical statistics of research data reduction. The study used discriminant analysis as the modeling method. Results: the classification results of motor preparedness of girls and boys aged 6-10 indicate that the study has correctly classified 81.9-100% of the initial observations. The graphic material demonstrates the density of objects within each class and a clear distinction between the classes. This allows to maintain that there is a significant difference between girls and boys aged 6-10 in their motor preparedness. Conclusions. The girls aged 6-10 show the best results in movement coordination related to combinations of movements of arms and legs, as well as flexibility. The girls aged 10 show the best results in test No. 10 “300-m Race”. The boys aged 6-10, unlike the girls, show the best results in the development of general coordination of movements, strength, speed strength, strength and general endurance. It is possible to argue with a high level of reliability that by their classification characteristics girls and boys belong to different classes, and significantly differ in motor preparedness.

A comparative study of using spindle motor power and eddy current for the detection of tool conditions in milling processes

OpenAIRE

Abbass, JK; Al-Habaibeh, A

2015-01-01

This paper investigates the use of the power of the driving motor of a CNC spindle in comparison to two perpendicular eddy current sensors for the detection of tool wear in milling processes. Monitoring the power through the current profile is a low cost system which has been utilised in this study as an attempt to detect the fluctuation in the motor load as a result of the conditions of the cutting tool. Eddy current sensors are dedicated sensors that are installed on the spindle to measure ...

49 CFR 178.320 - General requirements applicable to all DOT specification cargo tank motor vehicles.

Science.gov (United States)

2010-10-01

... removed from the motor vehicle; and (3) Is not fabricated under a specification for cylinders... determine leak tightness of the cargo tank when testing with pneumatic pressure. Internal self-closing stop...

Design and optimization of a modal- independent linear ultrasonic motor.

Science.gov (United States)

Zhou, Shengli; Yao, Zhiyuan

2014-03-01

To simplify the design of the linear ultrasonic motor (LUSM) and improve its output performance, a method of modal decoupling for LUSMs is proposed in this paper. The specific embodiment of this method is decoupling of the traditional LUSM stator's complex vibration into two simple vibrations, with each vibration implemented by one vibrator. Because the two vibrators are designed independently, their frequencies can be tuned independently and frequency consistency is easy to achieve. Thus, the method can simplify the design of the LUSM. Based on this method, a prototype modal- independent LUSM is designed and fabricated. The motor reaches its maximum thrust force of 47 N, maximum unloaded speed of 0.43 m/s, and maximum power of 7.85 W at applied voltage of 200 Vpp. The motor's structure is then optimized by controlling the difference between the two vibrators' resonance frequencies to reach larger output speed, thrust, and power. The optimized results show that when the frequency difference is 73 Hz, the output force, speed, and power reach their maximum values. At the input voltage of 200 Vpp, the motor reaches its maximum thrust force of 64.2 N, maximum unloaded speed of 0.76 m/s, maximum power of 17.4 W, maximum thrust-weight ratio of 23.7, and maximum efficiency of 39.6%.

Tissue-specific models of spinal muscular atrophy confirm a critical role of SMN in motor neurons from embryonic to adult stages.

Science.gov (United States)

Laird, Angela S; Mackovski, Nikolce; Rinkwitz, Silke; Becker, Thomas S; Giacomotto, Jean

2016-05-01

Spinal muscular atrophy (SMA) is an autosomal recessive disease linked to survival motor neuron (SMN) protein deficiency. While SMN protein is expressed ubiquitously, its deficiency triggers tissue-specific hallmarks, including motor neuron death and muscle atrophy, leading to impaired motor functions and premature death. Here, using stable miR-mediated knockdown technology in zebrafish, we developed the first vertebrate system allowing transgenic spatio-temporal control of the smn1 gene. Using this new model it is now possible to investigate normal and pathogenic SMN function(s) in specific cell types, independently or in synergy with other cell populations. We took advantage of this new system to first test the effect of motor neuron or muscle-specific smn1 silencing. Anti-smn1 miRNA expression in motor neurons, but not in muscles, reproduced SMA hallmarks, including abnormal motor neuron development, poor motor function and premature death. Interestingly, smn1 knockdown in motor neurons also induced severe late-onset phenotypes including scoliosis-like body deformities, weight loss, muscle atrophy and, seen for the first time in zebrafish, reduction in the number of motor neurons, indicating motor neuron degeneration. Taken together, we have developed a new transgenic system allowing spatio-temporal control of smn1 expression in zebrafish, and using this model, we have demonstrated that smn1 silencing in motor neurons alone is sufficient to reproduce SMA hallmarks in zebrafish. It is noteworthy that this research is going beyond SMA as this versatile gene-silencing transgenic system can be used to knockdown any genes of interest, filling the gap in the zebrafish genetic toolbox and opening new avenues to study gene functions in this organism. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A test of motor skill-specific action embodiment in ice-hockey players.

Science.gov (United States)

Ong, Nicole T; Lohse, Keith R; Chua, Romeo; Sinnett, Scott; Hodges, Nicola J

2014-07-01

To further our understanding of the role of the motor system in comprehending action-related sentences, we compared action experts (athletes) to visual experts (fans) and novices when responding with an action-specific effector (either hand or foot). These conditions allowed inferences about the degree and specificity of embodiment in language comprehension. Ice hockey players, fans and novices made speeded judgments regarding the congruence between an auditorily presented sentence and a subsequently presented picture. Picture stimuli consisted of either hockey or everyday items. Half of these pictures 'matched' the action implied in the preceding sentence. Further, the action in these images involved either primarily the hand or the foot. For everyday items, action-matched items were responded to faster than action-mismatched items. However, only the players and fans showed the action-match effect for hockey items. There were no consistent effector-stimuli compatibility effects, nor skill-based interactions with compatibility, suggesting that the action-match effect was not based on motor ability per se, but rather a construction of the action based on knowledge or visual experience with the hockey related sentences. Copyright © 2014 Elsevier B.V. All rights reserved.

Study and realization of the electronic power supply of a variable reluctance motor for electric-powered vehicle - motor experimenting; Etude et realisation de l'alimentation electronique d'un moteur a reluctance variable pour vehicule electrique - experimentation du moteur

Energy Technology Data Exchange (ETDEWEB)

Mouchoux, J.C.

1994-10-15

This work deals with the development of a propulsion system comprising a 27 kW double salience variable reluctance motor supplied by a tri-phase inverter with asymmetrical half-bridges capable to switch 400 A under 120 V. Control is ensured by a numerical control system based on a digital signal processor. The control strategy comprises two control modes: a torque trapeze one in order to minimize the undulations at low speed, and a full voltage wave one for high speeds (up to 10000 rpm) in order to use the full motor efficiency. This study presents: the operation principle of the motor and the control laws chosen, the converter design and testing, the elaboration of a single-phase numerical model of the motor, the analysis of the power supply simulation results for each control mode chosen, and the measurements of the control-converter-motor efficiencies. (J.S.)

Performance Analysis of a Hybrid Power Cutting System for Roadheader

Directory of Open Access Journals (Sweden)

Yang Yang

2017-01-01

Full Text Available An electrohydraulic hybrid power cutting transmission system for roadheader under specific working condition was proposed in this paper. The overall model for the new system composed of an electric motor model, a hydraulic pump-motor model, a torsional planetary set model, and a hybrid power train model was established. The working mode characteristics were simulated under the conditions of taking the effect of cutting picks into account. The advantages of new hybrid power cutting system about the dynamic response under shock load were investigated compared with the traditional cutting system. The results illustrated that the hybrid power system had an obvious cushioning in terms of the dynamic load of cutting electric motor and planetary gear set. Besides, the hydraulic motor could provide an auxiliary power to improve the performance of the electric motor. With further analysis, a dynamic load was found to have a high relation to the stiffness and damping of coupling in the transmission train. The results could be a useful guide for the design of cutting transmission of roadheader.

Apparatus for facilitating the servicing of inverted canned pump motors having limited access space and restricted access time especially in nuclear power plants

International Nuclear Information System (INIS)

Matusz, J.M.

1991-01-01

This patent describes a service apparatus for one or more inverted canned motor pumps installed above a floor and beneath a steam generator in a nuclear or fossil power plant with limited access space and limited access time at least in the case of nuclear power plants, each of the canned motor pumps having a pump casing and a depending motor having a flange secured to a pump casing flange by tensioned studs with tightened nuts. It comprises a maintenance cart having a height greater than the height of the motor beneath the motor flange and further having a generally U-shaped frame means with an open vertical side that permits the cart to be moved horizontally such that the cart frame means can be moved under the pump casing to surround the depending motor; actuator means supported by the cart frame means and having translating arm means engageable with support means on the motor; means for operating the translating arm means to support, raise and lower the motor; means supported by the frame means to support the motor flange prior to raising the motor to its installed position and after the motor has been released from its installed position and lowered to the cart; work platform means provided on the cart frame means at an elevation beneath the motor flange elevation; and roller means provided on the bottom of the cart frame means to facilitate horizontal cart movement along the floor

Apparatus and method for servicing an elongated suspended pump motor in an electric power plant with limited access

International Nuclear Information System (INIS)

Chavez, R.V.; Ekeroth, D.E.; Johnson, F.T.; Matusz, J.M.

1994-01-01

Elongated coolant pumps suspended under steam generators within containment in a power plant with limited access space, are removed and replaced by an elongated maintenance cart with an elongated opening along one side in which the motor is received. Rollers support the cart for conveying the elongated motor in an upright position out from under the steam generator and onto an elevator. The elevator is lowered to transfer support of the cart and motor through trunnions to saddles straddling the elevator for rotation of the cart to a generally horizontal position. The elevator then raises the horizontally disposed cart carrying the motor to a higher floor where it is rolled off the elevator and out through the auxiliary equipment hatch. 14 figures

Artificial molecular motors

NARCIS (Netherlands)

Kassem, Salma; van Leeuwen, Thomas; Lubbe, Anouk S.; Wilson, Miriam R.; Feringa, Ben L.; Leigh, David A.

2017-01-01

Motor proteins are nature's solution for directing movement at the molecular level. The field of artificial molecular motors takes inspiration from these tiny but powerful machines. Although directional motion on the nanoscale performed by synthetic molecular machines is a relatively new

Calculation of voltage drop during motors startup: power flow calculation by using the direct method; Calculo da queda de tensao na partida de motores: metodo direto do fluxo de potencia

Energy Technology Data Exchange (ETDEWEB)

Carvalho, Monaco [PETROBRAS, Rio de Janeiro, RJ (Brazil)

1998-07-01

In this paper, is presented a new theoretical approach developed in order to determine by direct method, non iterative, the load flow among the N bus bar of a generic power system. This method has been used to, from a single line simplified system of a typical industrial substation, used in the petroleum and by products storage and transportation facilities, calculate the voltage drops at bus bars and motors terminals from starting of the electric motors, after defining active and reactive power expressions flowing among bus bars, as a function of their voltages, impedance of connecting cables and of the loads connected to them. (author)

Motor-pump unit provided with a lifting appliance of the motor

International Nuclear Information System (INIS)

Veronesi, Luciano; Francis, W.R.

1978-01-01

This invention relates to lifting appliances and particularly concerns a 'pump and motor set' or motor-pump unit fitted with a lifting appliance enabling the motor to be separated from the pump. In nuclear power stations the reactor discharges heat that is carried by the coolant to a distant point away from the reactor to generate steam and electricity conventionally. In order to cause the reactor coolant to flow through the system, coolant motor-pump units are provided in the cooling system. These units are generally of the vertical type with an electric motor fitted vertically on the pump by means of a cylindrical or conical structure called motor support [fr

A MATLAB Graphical User Interface Dedicated to the Optimal Design of the High Power Induction Motor with Heavy Starting Conditions

Directory of Open Access Journals (Sweden)

Maria Brojboiu

2014-09-01

Full Text Available In this paper, a Matlab graphical user interface dedicated to the optimal design of the high power induction motor with heavy starting conditions is presented. This graphical user interface allows to input the rated parameters, the selection of the induction motor type and the optimization criterion of the induction motor design also. For the squirrel cage induction motor the graphical user interface allows the selection of the rotor bar geometry, the material of the rotor bar as well as the fastening technology of the shorting ring on the rotor bar. The Matlab graphical user interface is developed and applied to the general optimal design program of the induction motor described in [1], [2].

Cryogenic Electric Motor Tested

Science.gov (United States)

Brown, Gerald V.

2004-01-01

Technology for pollution-free "electric flight" is being evaluated in a number of NASA Glenn Research Center programs. One approach is to drive propulsive fans or propellers with electric motors powered by fuel cells running on hydrogen. For large transport aircraft, conventional electric motors are far too heavy to be feasible. However, since hydrogen fuel would almost surely be carried as liquid, a propulsive electric motor could be cooled to near liquid hydrogen temperature (-423 F) by using the fuel for cooling before it goes to the fuel cells. Motor windings could be either superconducting or high purity normal copper or aluminum. The electrical resistance of pure metals can drop to 1/100th or less of their room-temperature resistance at liquid hydrogen temperature. In either case, super or normal, much higher current density is possible in motor windings. This leads to more compact motors that are projected to produce 20 hp/lb or more in large sizes, in comparison to on the order of 2 hp/lb for large conventional motors. High power density is the major goal. To support cryogenic motor development, we have designed and built in-house a small motor (7-in. outside diameter) for operation in liquid nitrogen.

Electronically commutated dc motors for electric vehicles

Science.gov (United States)

Maslowski, E. A.

1981-01-01

A motor development program to explore the feasibility of electronically commutated dc motors (also known as brushless) for electric cars is described. Two different design concepts and a number of design variations based on these concepts are discussed. One design concept is based on a permanent magnet, medium speed, machine rated at 7000 to 9000 rpm, and powered via a transistor inverter power conditioner. The other concept is based on a permanent magnet, high speed, machine rated at 22,000 to 26,000 rpm, and powered via a thyristor inverter power conditioner. Test results are presented for a medium speed motor and a high speed motor each of which have been fabricated using samarium cobalt permanent magnet material.

Integrated-Circuit Controller For Brushless dc Motor

Science.gov (United States)

Le, Dong Tuan

1994-01-01

Generic circuit performs commutation-logic and power-switching functions for control of brushless dc motor. Controller includes commutation-logic and associated control circuitry, power supply, and inverters containing power transistors. Major advantages of controller are size, weight, and power consumption can be made less than other brushless-dc-motor controllers.

Influence of Language Load on Speech Motor Skill in Children With Specific Language Impairment.

Science.gov (United States)

Saletta, Meredith; Goffman, Lisa; Ward, Caitlin; Oleson, Jacob

2018-03-15

Children with specific language impairment (SLI) show particular deficits in the generation of sequenced action: the quintessential procedural task. Practiced imitation of a sequence may become rote and require reduced procedural memory. This study explored whether speech motor deficits in children with SLI occur generally or only in conditions of high linguistic load, whether speech motor deficits diminish with practice, and whether it is beneficial to incorporate conditions of high load to understand speech production. Children with SLI and typical development participated in a syntactic priming task during which they generated sentences (high linguistic load) and, then, practiced repeating a sentence (low load) across 3 sessions. We assessed phonetic accuracy, speech movement variability, and duration. Children with SLI produced more variable articulatory movements than peers with typical development in the high load condition. The groups converged in the low load condition. Children with SLI continued to show increased articulatory stability over 3 practice sessions. Both groups produced generated sentences with increased duration and variability compared with repeated sentences. Linguistic demands influence speech motor production. Children with SLI show reduced speech motor performance in tasks that require language generation but not when task demands are reduced in rote practice.

Procedure of qualification applied to motors driving auxiliaries in fossil fired and nuclear power plants

International Nuclear Information System (INIS)

Coperchini, C.; Fises, A.

1984-01-01

Twenty year operation have enabled EDF to better understand the factors improving the reliability of powerhouse auxiliary drive induction motors. Progress in the behaviour of such machines are mainly due to analysis and handling of full size test results achieved in the Saint-Denis Motor Test Laboratory. This work led to the printing of recommendations and technical specifications. Service and safety requirements of the nuclear plant new generation lead to examine again the procedures of qualification. The analysis made in this report let appear the justification to maintain the present EDF policy with some necessary adjustments, especially as far as the nuclear safety motors are concerned [fr

Comparison of capabilities of reluctance synchronous motor and induction motor

International Nuclear Information System (INIS)

Stumberger, Gorazd; Hadziselimovic, Miralem; Stumberger, Bojan; Miljavec, Damijan; Dolinar, Drago; Zagradisnik, Ivan

2006-01-01

This paper compares the capabilities of a reluctance synchronous motor (RSM) with those of an induction motor (IM). An RSM and IM were designed and made, with the same rated power and speed. They differ only in the rotor portion while their stators, housings and cooling systems are identical. The capabilities of both motors in a variable speed drive are evaluated by comparison of the results obtained by magnetically nonlinear models and by measurements

Motor recovery in post-stroke patients with aphasia: the role of specific linguistic abilities.

Science.gov (United States)

Ginex, Valeria; Veronelli, Laura; Vanacore, Nicola; Lacorte, Eleonora; Monti, Alessia; Corbo, Massimo

2017-09-01

Aphasia is a serious consequence of stroke but aphasics patients have been routinely excluded from participation in some areas of stroke research. To assess the role of specific linguistic and non-verbal cognitive abilities on the short-term motor recovery of patients with aphasia due to first-ever stroke to the left hemisphere after an intensive rehabilitation treatment. 48 post-acute aphasic patients, who underwent physiotherapy and speech language therapy, were enrolled for this retrospective cohort-study. Four types of possible predictive factors were taken into account: clinical variables, functional status, language and non-verbal cognitive abilities. The motor FIM at discharge was used as the main dependent variable. Patients were classified as follows: 6 amnestic, 9 Broca's, 7 Wernicke's, and 26 global aphasics. Motor FIM at admission (p = 0.003) and at discharge (p = 0.042), all linguistic subtests of Aachener AphasieTest (p = 0.001), and non-verbal reasoning abilities (Raven's CPM, p = 0.006) resulted significantly different across different types of aphasia. Post-hoc analyses showed differences only between global aphasia and the other groups. A Multiple Linear Regression shows that admission motor FIM (p = 0.001) and Token test (p = 0.040), adjusted for clinical, language, and non-verbal reasoning variables, resulted as independent predictors of motor FIM scores at discharge, while Raven's CPM resulted close to statistical significance. Motor function at admission resulted as the variable that most affects the motor recovery of post-stroke patients with aphasia after rehabilitation. A linguistic test requiring also non-linguistic abilities, including attention and working memory (i.e. Token test) is an independent predictor as well.

High-speed AC motors

Energy Technology Data Exchange (ETDEWEB)

Jokinen, T.; Arkkio, A. [Helsinki University of Technology Laboratory of Electromechanics, Otaniemi (Finland)

1997-12-31

The paper deals with various types of highspeed electric motors, and their limiting powers. Standard machines with laminated rotors can be utilised if the speed is moderate. The solid rotor construction makes it possible to reach higher power and speed levels than those of laminated rotors. The development work on high-speed motors done at Helsinki University of Technology is presented, too. (orig.) 12 refs.

Application of power spectrum, cepstrum, higher order spectrum and neural network analyses for induction motor fault diagnosis

Science.gov (United States)

Liang, B.; Iwnicki, S. D.; Zhao, Y.

2013-08-01

The power spectrum is defined as the square of the magnitude of the Fourier transform (FT) of a signal. The advantage of FT analysis is that it allows the decomposition of a signal into individual periodic frequency components and establishes the relative intensity of each component. It is the most commonly used signal processing technique today. If the same principle is applied for the detection of periodicity components in a Fourier spectrum, the process is called the cepstrum analysis. Cepstrum analysis is a very useful tool for detection families of harmonics with uniform spacing or the families of sidebands commonly found in gearbox, bearing and engine vibration fault spectra. Higher order spectra (HOS) (also known as polyspectra) consist of higher order moment of spectra which are able to detect non-linear interactions between frequency components. For HOS, the most commonly used is the bispectrum. The bispectrum is the third-order frequency domain measure, which contains information that standard power spectral analysis techniques cannot provide. It is well known that neural networks can represent complex non-linear relationships, and therefore they are extremely useful for fault identification and classification. This paper presents an application of power spectrum, cepstrum, bispectrum and neural network for fault pattern extraction of induction motors. The potential for using the power spectrum, cepstrum, bispectrum and neural network as a means for differentiating between healthy and faulty induction motor operation is examined. A series of experiments is done and the advantages and disadvantages between them are discussed. It has been found that a combination of power spectrum, cepstrum and bispectrum plus neural network analyses could be a very useful tool for condition monitoring and fault diagnosis of induction motors.

Experiments with a dc motor

International Nuclear Information System (INIS)

Kraftmakher, Yaakov

2010-01-01

Experiments with an electric motor provide good opportunity to demonstrate some basic laws of electricity and magnetism. The aim of the experiments with a low-power dc motor is to show how the motor approaches its steady rotation and how its torque, mechanical power and efficiency depend on the rotation velocity. The tight relationship between the mechanical and electrical parameters of the motor is clearly seen. The measurements are carried out with the ScienceWorkshop data-acquisition system and the DataStudio software from PASCO scientific. The experiments are well related to university courses of electricity and magnetism and can be used in undergraduate laboratories or for lecture demonstrations.

Fault Diagnosis of Low-Power Three-Phase Induction Motor

Directory of Open Access Journals (Sweden)

Gedzurs Aleksejs

2016-12-01

Full Text Available An Induction motor reliability survey at an egg processing plant shows that almost 50% of the total motor failures are fan induction motors. Visual investigations of the faulty fan motors show that the main cause of the induction motor failure is air gap eccentricity. In this study, experimental tests are performed on a 1.1kW three-phase induction motor to detect air gap eccentricity and overheating of the induction motor. Heating tests show that end shield housing temperature reaches 100°C with blocked air flow from the fan, which can reduce the lifespan of the bearing. Dimension measurements of the end shield housing show that the dimensions of both tested motors back-end shields are larger than ISO tolerance grade limit. It leads to a loose fit between the housing and bearing, causing air gap eccentricity. Also, both motor back end shield housing has an out-of-round condition leading to an unbalanced magnetic pull. To detect the air gap eccentricity caused by too loose of a fit between housing bore and bearing, current Park’s vector approach is used. To measure three phase current, Hall Effect current transducers, a digital oscilloscope is used and Matlab software to process the measurement data. Results show that Park’s vector approach can be used to detect the air gap eccentricity caused by too loose a fit between bearing and housing. Therefore, the Park’s vector approach can be used to diagnose air gap eccentricity and analyse the type of the air gap eccentricity.

Rehabilitation after stroke: predictive power of Barthel Index versus a cognitive and a motor index

DEFF Research Database (Denmark)

Engberg, A; Bentzen, L; Garde, B

1995-01-01

The aim of the present study was to investigate the predictive power of ratings of Barthel Index at Day 40 post stroke, compared with and/or combined with simultaneous ratings from a mobility scale (EG motor index) and a rather simple cognitive test scale (CT50). The parameter to be individually...

Analysis of Electric Propulsion Performance on Submersible with Motor DC, Supply Power 10260AH at Voltage 115VDC

Directory of Open Access Journals (Sweden)

Indra Ranu Kusuma

2017-03-01

Full Text Available Electric propulsion is the ship system using propulsion motor to replace performance of main engine. The application of diesel engine as propulsion system have some problems and weaknesses such as diesel engine unability to operate when submersible vessel is operating under sea. To overcome that problems in submersible vessel, alternative solution of ship propulsion is required. DC Motor can be used as this alternative solution. Submersible vessel use electric propulsion system with DC Motor because DC Motor has advantages of easy rotation setting and does not cause noise when submersible vessel is diving. This bachelor thesis will study the application of DC Motor as an electric propulsion system on submersible vessel with length 59,57 m in series and parallel circuit by simulation using MATLAB software. The simulation data obtained are rotation and torque of DC Motor. From these simulation, it can be concluded that parallel circuit rotation is greater than series circuit rotation. It caused the greater speed and lower power in parallel circuit. 

Pulse-Width-Modulating Driver for Brushless dc Motor

Science.gov (United States)

Salomon, Phil M.

1991-01-01

High-current pulse-width-modulating driver for brushless dc motor features optical coupling of timing signals from low-current control circuitry to high-current motor-driving circuitry. Provides high electrical isolation of motor-power supply, helping to prevent fast, high-current motor-driving pulses from being coupled through power supplies into control circuitry, where they interfere with low-current control signals.

Optimization of geometry of annular seat valves suitable for Digital Displacement fluid power pumps/motors

DEFF Research Database (Denmark)

Rømer, Daniel; Johansen, Per; Pedersen, Henrik C.

2013-01-01

Digital Displacement Fluid Power is an upcoming technology setting new standards for the achievable efficiency of fluid power pumps and motors. The core element of the Digital Displacement technology is high performance electronically controlled seat valves, which must exhibit very low flow...... work an annular seat valve suitable for use in Digital Displacement units is considered, and the ring geometry is optimized using finite element analysis including non-linear material behaviour, contact elements and fluid pressure penetrating load, closely reflecting the actual load of the seat valve...

Influence of Language Load on Speech Motor Skill in Children with Specific Language Impairment

Science.gov (United States)

Saletta, Meredith; Goffman, Lisa; Ward, Caitlin; Oleson, Jacob

2018-01-01

Purpose: Children with specific language impairment (SLI) show particular deficits in the generation of sequenced action--the quintessential procedural task. Practiced imitation of a sequence may become rote and require reduced procedural memory. This study explored whether speech motor deficits in children with SLI occur generally or only in…

Reactive Power Compensating System.

Energy Technology Data Exchange (ETDEWEB)

Williams, Timothy J.; El-Sharkawi, Mohamed A.; Venkata, Subrahmanyam S.

1985-01-04

The circuit was designed for the specific application of wind-driven induction generators. It has great potential for application in any situation where a varying reactive power load is present, such as with induction motors or generators, or for transmission network compensation.

Concurrent word generation and motor performance: further evidence for language-motor interaction.

Directory of Open Access Journals (Sweden)

Amy D Rodriguez

Full Text Available Embodied/modality-specific theories of semantic memory propose that sensorimotor representations play an important role in perception and action. A large body of evidence supports the notion that concepts involving human motor action (i.e., semantic-motor representations are processed in both language and motor regions of the brain. However, most studies have focused on perceptual tasks, leaving unanswered questions about language-motor interaction during production tasks. Thus, we investigated the effects of shared semantic-motor representations on concurrent language and motor production tasks in healthy young adults, manipulating the semantic task (motor-related vs. nonmotor-related words and the motor task (i.e., standing still and finger-tapping. In Experiment 1 (n = 20, we demonstrated that motor-related word generation was sufficient to affect postural control. In Experiment 2 (n = 40, we demonstrated that motor-related word generation was sufficient to facilitate word generation and finger tapping. We conclude that engaging semantic-motor representations can have a reciprocal influence on motor and language production. Our study provides additional support for functional language-motor interaction, as well as embodied/modality-specific theories.

Static Analysis of High-Performance Fixed Fluid Power Drive with a Single Positive-Displacement Hydraulic Motor

Directory of Open Access Journals (Sweden)

O. F. Nikitin

2015-01-01

Full Text Available The article deals with the static calculations in designing a high-performance fixed fluid power drive with a single positive-displacement hydraulic motor. Designing is aimed at using a drive that is under development and yet unavailable to find and record the minimum of calculations and maximum of existing hydraulic units that enable clear and unambiguous performance, taking into consideration an available assortment of hydraulic units of hydraulic drives, to have the best efficiency.The specified power (power, moment and kinematics (linear velocity or angular velocity of rotation parameters of the output element of hydraulic motor determine the main output parameters of the hydraulic drive and the useful power of the hydraulic drive under development. The value of the overall efficiency of the hydraulic drive enables us to judge the efficiency of high-performance fixed fluid power drive.The energy analysis of a diagram of the high-performance fixed fluid power drive shows that its high efficiency is achieved when the flow rate of fluid flowing into each cylinder and the magnitude of the feed pump unit (pump are as nearly as possible.The paper considers the ways of determining the geometric parameters of working hydromotors (effective working area or working volume, which allow a selection of the pumping unit parameters. It discusses the ways to improve hydraulic drive efficiency. Using the principle of holding constant conductivity allows us to specify the values of the pressure losses in the hydraulic units used in noncatalog modes. In case of no exact matching between the parameters of existing hydraulic power modes and a proposed characteristics of the pump unit, the nearest to the expected characteristics is taken as a working version.All of the steps allow us to create the high-performance fixed fluid power drive capable of operating at the required power and kinematic parameters with high efficiency.

A smart dust biosensor powered by kinesin motors.

Science.gov (United States)

Fischer, Thorsten; Agarwal, Ashutosh; Hess, Henry

2009-03-01

Biosensors can be miniaturized by either injecting smaller volumes into micro- and nanofluidic devices or immersing increasingly sophisticated particles known as 'smart dust' into the sample. The term 'smart dust' originally referred to cubic-millimetre wireless semiconducting sensor devices that could invisibly monitor the environment in buildings and public spaces, but later it also came to include functional micrometre-sized porous silicon particles used to monitor yet smaller environments. The principal challenge in designing smart dust biosensors is integrating transport functions with energy supply into the device. Here, we report a hybrid microdevice that is powered by ATP and relies on antibody-functionalized microtubules and kinesin motors to transport the target analyte into a detection region. The transport step replaces the wash step in traditional double-antibody sandwich assays. Owing to their small size and autonomous function, we envision that large numbers of such smart dust biosensors could be inserted into organisms or distributed into the environment for remote sensing.

On the Drive Specificity of Freudian Drives for the Generation of SEEKING Activities: The Importance of the Underestimated Imperative Motor Factor

Directory of Open Access Journals (Sweden)

Michael Kirsch

2018-05-01

Full Text Available Doubters of Freud’s theory of drives frequently mentioned that his approach is outdated and therefore cannot be useful for solving current problems in patients with mental disorders. At present, many scientists believe that affects rather than drives are of utmost importance for the emotional life and the theoretical framework of affective neuroscience, developed by Panksepp, strongly underpinned this view. Panksepp evaluated seven so-called command systems and the SEEKING system is therein of central importance. Panksepp used Pankseppian drives as inputs for the SEEKING system but noted the missing explanation of drive-specific generation of SEEKING activities in his description. Drive specificity requires dual action of the drive: the activation of a drive-specific brain area and the release of the neurotransmitter dopamine. Noticeably, as Freud claimed drive specificity too, it was here analyzed whether a Freudian drive can evoke the generation of drive-specific SEEKING activities. Special importance was addressed to the imperative motor factor in Freud’s drive theory because Panksepp’s formulations focused on neural pathways without specifying underlying neurotransmitter/endocrine factors impelling motor activity. As Panksepp claimed sleep as a Pankseppian drive, we firstly had to classified sleep as a Freudian drive by using three evaluated criteria for a Freudian drive. After that it was possible to identify the imperative motor factors of hunger, thirst, sex, and sleep. Most importantly, all of these imperative motor factors can both activate a drive-specific brain area and release dopamine from dopaminergic neurons, i.e., they can achieve the so-called drive specificity. Surprisingly, an impaired Freudian drive can alter via endocrinological pathways the concentration of the imperative motor factor of a second Freudian drive, obviously in some independence to the level of the metabolic deficit, thereby offering the possibility to

Reduction of power consumption in motor-driven applications by using PM motors; PM = Permanent Magnet; Reduktion af elforbrug til motordrift ved anvendelse af PM motorer

Energy Technology Data Exchange (ETDEWEB)

Hvenegaard, C.M.; Hansen, Mads P.R.; Groenborg Nikolaisen, C. (Teknologisk Institut, Taastrup (Denmark)); Nielsen, Sandie B. (Teknologisk Institut, AArhus (Denmark)); Ritchie, E.; Leban, K. (Aalborg Univ., Aalborg (Denmark))

2009-12-15

The traditional asynchronous motor with aluminum rotor is today by far the most widespread and sold electric motor, but a new and more energy efficient type of engine - the permanent magnet motor (PM motor) - is expected in the coming years to win larger and larger market shares. Several engine manufacturers in Europe, USA and Asia are now beginning to market the PM motors, which can replace the traditional asynchronous motor. The project aims to uncover the pros and cons of replacing asynchronous motors including EFF1 engines with PM motors, including the price difference. Furthermore, it is identified how the efficiency of PM motors is affected by low load levels and at various forms of control. Finally, the energy savings potential is analysed, by replacing asynchronous motors with PM motors. The study includes laboratory tests of PM motors, made in a test stand at Danish Technological Institute. (ln)

Development of an induction motor abnormality monitoring system(IMAMS) using power line signal analysis

International Nuclear Information System (INIS)

Jung, Jae Cheon

1997-02-01

An induction motor abnormality monitoring system using power line signal analysis is developed in this work. Various studies have focused their attention on the detection of particular harmonic frequencies produced from each defect mode of motors. However, these harmonic frequencies are valuable only when the motor has a continuous slip frequency and operate in constant torque/load condition. The basic concept of the system developed in this work is to detect the characteristic harmonic frequencies occurred when the motor is in abnormal state and to compare it with a predetermined setpoint. Based on these analyses, the place and degree of defect can be easily identified. The experimental results under test bench simulation are also introduced. To find out an alternative way to obtain a threshold level independent of slip/torque, with the rotating field theory, the ratio between harmonic current and total current was calculated with the simplified circuit that is equivalent to two abnormal cases, such as the spatial rotor resistance variation and the symmetrical components changes with field. Also, the threshold level calculation was done with performed the rotating field theory. The results show that they are in good agreement with a experimental results. Further studies are undertaken to extend this work to the on-line monitoring and diagnostic system with a likelihood ratio test method for field application

Aging assessment of large electric motors in nuclear power plants

International Nuclear Information System (INIS)

Villaran, M.; Subudhi, M.

1996-03-01

Large electric motors serve as the prime movers to drive high capacity pumps, fans, compressors, and generators in a variety of nuclear plant systems. This study examined the stressors that cause degradation and aging in large electric motors operating in various plant locations and environments. The operating history of these machines in nuclear plant service was studied by review and analysis of failure reports in the NPRDS and LER databases. This was supplemented by a review of motor designs, and their nuclear and balance of plant applications, in order to characterize the failure mechanisms that cause degradation, aging, and failure in large electric motors. A generic failure modes and effects analysis for large squirrel cage induction motors was performed to identify the degradation and aging mechanisms affecting various components of these large motors, the failure modes that result, and their effects upon the function of the motor. The effects of large motor failures upon the systems in which they are operating, and on the plant as a whole, were analyzed from failure reports in the databases. The effectiveness of the industry's large motor maintenance programs was assessed based upon the failure reports in the databases and reviews of plant maintenance procedures and programs

Study on the VFD (Variable Frequency Drive) for RCP (Reactor Coolant Pump) Motors of APR1400

Energy Technology Data Exchange (ETDEWEB)

Park, Jung Ha; Robert, M. Field; Kim, Tae Ryong [Department of NPP Engineering, KEPCO International Nuclear Graduate School, Ulsan (Korea, Republic of)

2014-10-15

Most industrial facilities are continually searching for ways to reduce energy costs while increasing or maintaining current production. In terms of electric motors, Variable Frequency Drive (VFD) units represent a critical opportunity for energy savings. Currently, VFDs are used on about ten (10) percent of industrial process motors, and this percentage is increasing every year. Properly applied VFDs have been documented to save as much as fifty percent of the energy consumed by certain industrial processes. Nuclear Power - Power plants in general and Nuclear Power Plants (NPPs) in particular are slow to adopt new technology. The nuclear power industry requires a nearly absolute demonstration through operating experience in other industries in which the new approach will result in a net improvement in plant reliability without any surprises. Only recently has the nuclear industry begun to adapt VFD units for large motors. Specifically, there are several examples in the Boiling Water Reactor (BWR) fleet of replacing Motor-Generator (M-G) sets with VFD units for Reactor Recirculation (RR) pump motor service. At one station, VFD units were introduced upstream of the Circulating Water (CWP) pump motors to address environmental issues. They units are taking advantage of VFD technology whose benefits include increased reliability, reduction in electrical house load, improved flow control, and reduced maintenance. RCP Application - In the case of new generation, it has been reported that the Westinghouse AP1000 will make use of VFD units for the Reactor Coolant Pump (RCP) motors.

Electric motor predictive and preventive maintenance guide

International Nuclear Information System (INIS)

Oliver, J.A.

1992-07-01

Electric motor performance is vital to the reliable and efficient operation of power plants. The failure of one or more critical motors could cause lost capacity and excessive repair and maintenance cost. However, existing maintenance recommendations proposed by vendors for electric motors have sometimes encouraged many overly conservative maintenance practices. These practices have lead to excessive maintenance activities and costs which have provided no extra margin of operability. EPRI has sponsored RP2814-35 to develop a guide which provides power plants with information and guidance for establishing an effective maintenance program which will aid in preventing unexpected motor failures and assist in planning motor maintenance efforts. The guide includes a technical description which summarizes technical data relative to the four basic types of motors and their components in general use in power plants. The significant causes of motor failures are investigated and described in detail and methods to optimize service life and minimize maintenance cost through appropriate preventive maintenance and conditioning program are presented. This guide provides a foundation for an effective electric motor maintenance program and simplifies the selection of predictive and preventive maintenance tasks. Its use will enable maintenance personnel in nuclear and fossil plants to plan motor repairs during scheduled outages and avoid costly unexpected failures

RELATIONS BETWEEN BASIC MOTOR ABILITIES AND SPECIFIC PRECISENESS OF FOOTBALLERS AGED 10-12

Directory of Open Access Journals (Sweden)

Miroslav Smajić

2007-05-01

Full Text Available According to the research on the sample of 256 footballers aged 10-12 and the battery including 20 tests for evaluation of the basic motor abilities and the battery of 24 tests for evaluation of specifi c preciseness, and as per canonic-correlation analysis, a general conclusion can be reached that the boys were rather different in their basic motor abilities. The differences were especially high in explosive strength, coordination, aerobic endurance and balance. One could also conclude that the sample treated in this manner (10-12 years of age is very heterogeneous with respect to basic motor abilities. The subjects showed the highest homogeneity in the tests of specifi c preciseness. They also achieved particularly good results in the tests of vertical target hitting by leg and head. Considering the relations of the basic motor abilities and specifi c preciseness, it was concluded that the structure-based basic motor-canonic factor might be interpreted as FACTOR OF SPEED ENDURANCE AND EXPLOSIVE STRENGTH, whereas structurebased canonic factor of specifi c preciseness might be interpreted as the FACTOR OF SPECIFIC PRECISENESS OF VERTICAL TARGET HITTING BY LEG AND HEAD. The structure of the relations of the fi rst pair of canonic factors indicates that footballers with lower speed endurance and lower explosive strength achieved poorer results in the tests of specifi c preciseness of vertical target hitting by leg and head, and vice versa. Structure of the relations of the second canonic factor indicates quite clearly that the footballers with lower repetitive strength achieved lower results in the tests of specifi c preciseness of horizontal and vertical target by leg and head in a newly created situation. Here of course, the opposite was true, i.e. footballers with higher repetitive strength were better in these tests too.

Electric vehicle motors and controllers

Science.gov (United States)

Secunde, R. R.

1981-01-01

Improved and advanced components being developed include electronically commutated permanent magnet motors of both drum and disk configuration, an unconventional brush commutated motor, and ac induction motors and various controllers. Test results on developmental motors, controllers, and combinations thereof indicate that efficiencies of 90% and higher for individual components, and 80% to 90% for motor/controller combinations can be obtained at rated power. The simplicity of the developmental motors and the potential for ultimately low cost electronics indicate that one or more of these approaches to electric vehicle propulsion may eventually displace presently used controllers and brush commutated dc motors.

HTSL massive motor. Project: Motor field calculation. Final report

International Nuclear Information System (INIS)

Gutt, H.J.; Gruener, A.

2003-01-01

HTS motors up to 300 kW were to be developed and optimized. For this, specific calculation methods were enhanced to include superconducting rotor types (hysteresis, reluctance and permanent magnet HTS rotors). The experiments were carried out in a SHM70-45 hysteresis motor. It was shown how static and dynamic trapped field magnetisation of the rotor with YBCO rings will increase flux in the air gap motor, increasing the motor capacity to twice its original level. (orig.) [de

Imagining is Not Doing but Involves Specific Motor Commands: A Review of Experimental Data Related to Motor Inhibition.

Science.gov (United States)

Guillot, Aymeric; Di Rienzo, Franck; Macintyre, Tadhg; Moran, Aidan; Collet, Christian

2012-01-01

There is now compelling evidence that motor imagery (MI) and actual movement share common neural substrate. However, the question of how MI inhibits the transmission of motor commands into the efferent pathways in order to prevent any movement is largely unresolved. Similarly, little is known about the nature of the electromyographic activity that is apparent during MI. In addressing these gaps in the literature, the present paper argues that MI includes motor execution commands for muscle contractions which are blocked at some level of the motor system by inhibitory mechanisms. We first assemble data from neuroimaging studies that demonstrate that the neural networks mediating MI and motor performance are not totally overlapping, thereby highlighting potential differences between MI and actual motor execution. We then review MI data indicating the presence of subliminal muscular activity reflecting the intrinsic characteristics of the motor command as well as increased corticomotor excitability. The third section not only considers the inhibitory mechanisms involved during MI but also examines how the brain resolves the problem of issuing the motor command for action while supervising motor inhibition when people engage in voluntary movement during MI. The last part of the paper draws on imagery research in clinical contexts to suggest that some patients move while imagining an action, although they are not aware of such movements. In particular, experimental data from amputees as well as from patients with Parkinson's disease are discussed. We also review recent studies based on comparing brain activity in tetraplegic patients with that from healthy matched controls that provide insights into inhibitory processes during MI. We conclude by arguing that based on available evidence, a multifactorial explanation of motor inhibition during MI is warranted.

Imagining is not doing but involves specific motor commands: a review of experimental data related to motor inhibition

Directory of Open Access Journals (Sweden)

Aymeric eGuillot

2012-09-01

Full Text Available There is now compelling evidence that motor imagery (MI and actual movement share common neural substrate. However, the question of how MI inhibits the transmission of motor commands into the efferent pathways in order to prevent any movement is largely unresolved. Similarly, little is known about the nature of the electromyographic activity that is apparent during MI. In addressing these gaps in the literature, the present paper argues that MI includes motor execution commands for muscle contractions which are blocked at some level of the motor system by inhibitory mechanisms. We first assemble data from neuroimaging studies that demonstrate that the neural networks mediating MI and motor performance are not totally overlapping, thereby highlighting potential differences between MI and actual motor execution. We then review MI data indicating the presence of subliminal muscular activity reflecting the intrinsic characteristics of the motor command as well as increased corticomotor excitability. The third section not only considers the inhibitory mechanisms involved during MI but also examines how the brain resolves the problem of issuing the motor command for action while supervising motor inhibition when people engage in voluntary movement during MI. The last part of the paper draws on imagery research in clinical contexts to suggest that some patients move while imagining an action, although they are not aware of such movements. In particular, experimental data from amputees as well as from patients with Parkinson’s disease are discussed. We also review recent studies based on comparing brain activity in tetraplegic patients with that from healthy matched controls that provide insights into inhibitory processes during MI. We conclude by arguing that based on available evidence, a multifactorial explanation of motor inhibition during MI is warranted.

Electric motor handbook

CERN Document Server

Chalmers, B J

2013-01-01

Electric Motor Handbook aims to give practical knowledge in a wide range of capacities such as plant design, equipment specification, commissioning, operation and maintenance. The book covers topics such as the modeling of steady-state motor performance; polyphase induction, synchronous, and a.c. commutator motors; ambient conditions, enclosures, cooling and loss dissipation; and electrical supply systems and motor drives. Also covered are topics such as variable-speed drives and motor control; materials and motor components; insulation types, systems, and techniques; and the installation, sit

SLIPPER PERFORMANCE INVESTIGATION IN AXIAL PISTON PUMPS AND MOTORS-FLOW AND VISCOUS POWER LOSSES

Directory of Open Access Journals (Sweden)

A. Osman KURBAN

1997-01-01

Full Text Available In this study, the slippers being the most effective on the performance of swash plate type axial piston pumps and motors, which is a good example of hydrodynamic-hydrostatic bearing applications, have been investigated. With respect to this, having derived the viscous moment loss, viscous flow leakage loss and power loss equations, the variations of these parameters under different operating conditions have been examined experimentally.

Motor unit number index (MUNIX) derivation from the relationship between the area and power of surface electromyogram: a computer simulation and clinical study

Science.gov (United States)

Miralles, Francesc

2018-06-01

Objective. The motor unit number index (MUNIX) is a technique based on the surface electromyogram (sEMG) that is gaining acceptance as a method for monitoring motor neuron loss, because it is reliable and produces less discomfort than other electrodiagnostic techniques having the same intended purpose. MUNIX assumes that the relationship between the area of sEMG obtained at increasing levels of muscle activation and the values of a variable called ‘ideal case motor unit count’ (ICMUC), defined as the product of the ratio between area and power of the compound muscle action potential (CMAP) by that of the sEMG, is described by a decreasing power function. Nevertheless, the reason for this comportment is unknown. The objective of this work is to investigate if the definition of MUNIX could derive from more basic properties of the sEMG. Approach. The CMAP and sEMG epochs obtained at different levels of muscle activation from (1) the abductor pollicis brevis (APB) muscle of persons with and without a carpal tunnel syndrome (CTS) and (2) from a computer model of sEMG generation previously published were analysed. Main results. MUNIX reflects the power relationship existing between the area and power of a sEMG. The exponent of this function was smaller in patients with motor CTS than in the rest of the subjects. The analysis of the relationship between the area and power of a sEMG could aid in distinguishing a MUNIX reduction due to a motoneuron loss from that due to a loss of muscle fibre. Significance. MUNIX is derived from the relationship between the area and power of a sEMG. This relationship changes when there is a loss of motor units (MUs), which partially explains the diagnostic sensibility of MUNIX. Although the reasons for this change are unknown, it could reflect an increase in the proportion of MUs of great amplitude.

IE Information No. 87-08: Degraded motor leads in Limitorque dc motor operators

International Nuclear Information System (INIS)

Jordan, E.L.

1992-01-01

On May 6, 1986 the NRC received from Portland General Electric Company a 10 CFR 21 report concerning a motor failure which occurred at its Trojan Nuclear Power Plant. The failure involved shorting of the motor leads inside a Limitorque motor operator connected to an auxiliary feedwater flow control valve. Upon inspection it was determined that the failure was the result of insulation degradation of the motor leads that had allowed two leads to short together. Recently, the NRC has also learned of a failure at the Turkey Point Nuclear Power Plant in which the steam supply valve for the auxiliary feedwater turbine failed to operate after a Limitorque motor operator experienced a similar motor lead short circuit. The Trojan and the Turkey Point Limitorque operators were found to contain motors manufactured with Nomex-Kapton insulated leads. On January 12--14, 1987, the NRC conducted an inspection at Peerless-Winsmith, Inc., manufacturer of dc motors for Limitorque Co. During this inspection it was determined that the failed Nomex-Kapton leads were different than the leads which were fitted to the motors, tested, and documented in Limitorque Qualification Report B-0009 for dc motor operators. The leads attached to the tested motors were insulated with Nomex plus an epoxy impregnated braided fiberglass sleeve. The NRC knows of no analysis or testing that has been performed to show the Nomex-Kapton leads are acceptable for use in an application requiring environmental qualification. Further, it should be noted that the failures cited above occurred under normal operating conditions, not under the harsh conditions which could occur in areas where environmental qualification is required

Variation in motor output and motor performance in a centrally generated motor pattern

Science.gov (United States)

Norris, Brian J.; Doloc-Mihu, Anca; Calabrese, Ronald L.

2014-01-01

Central pattern generators (CPGs) produce motor patterns that ultimately drive motor outputs. We studied how functional motor performance is achieved, specifically, whether the variation seen in motor patterns is reflected in motor performance and whether fictive motor patterns differ from those in vivo. We used the leech heartbeat system in which a bilaterally symmetrical CPG coordinates segmental heart motor neurons and two segmented heart tubes into two mutually exclusive coordination modes: rear-to-front peristaltic on one side and nearly synchronous on the other, with regular side-to-side switches. We assessed individual variability of the motor pattern and the beat pattern in vivo. To quantify the beat pattern we imaged intact adults. To quantify the phase relations between motor neurons and heart constrictions we recorded extracellularly from two heart motor neurons and movement from the corresponding heart segments in minimally dissected leeches. Variation in the motor pattern was reflected in motor performance only in the peristaltic mode, where larger intersegmental phase differences in the motor neurons resulted in larger phase differences between heart constrictions. Fictive motor patterns differed from those in vivo only in the synchronous mode, where intersegmental phase differences in vivo had a larger front-to-rear bias and were more constrained. Additionally, load-influenced constriction timing might explain the amplification of the phase differences between heart segments in the peristaltic mode and the higher variability in motor output due to body shape assumed in this soft-bodied animal. The motor pattern determines the beat pattern, peristaltic or synchronous, but heart mechanics influence the phase relations achieved. PMID:24717348

"Fan-Tip-Drive" High-Power-Density, Permanent Magnet Electric Motor and Test Rig Designed for a Nonpolluting Aircraft Propulsion Program

Science.gov (United States)

Brown, Gerald V.; Kascak, Albert F.

2004-01-01

A scaled blade-tip-drive test rig was designed at the NASA Glenn Research Center. The rig is a scaled version of a direct-current brushless motor that would be located in the shroud of a thrust fan. This geometry is very attractive since the allowable speed of the armature is approximately the speed of the blade tips (Mach 1 or 1100 ft/s). The magnetic pressure generated in the motor acts over a large area and, thus, produces a large force or torque. This large force multiplied by the large velocity results in a high-power-density motor.

EEG alpha activity reflects motor preparation rather than the mode of action selection

Directory of Open Access Journals (Sweden)

Marie-Pierre eDeiber

2012-08-01

Full Text Available Alpha-band activity (8-13 Hz is suppressed by sensory stimulation and movements, modulated by attention, working memory and mental tasks and may be sensitive to higher motor control functions. The aim of the present study was to examine alpha oscillatory activity during the preparation of simple left or right finger movements, contrasting the external and internal mode of action selection. Three preparation conditions were examined using a precueing paradigm with S1 as the preparatory and S2 as the imperative cue: Full, laterality instructed by S1; Free, laterality freely selected and None, laterality instructed by S2. Time-frequency analysis was performed in the alpha frequency range during the S1-S2 interval, and alpha motor-related amplitude asymmetries (MRAA were also calculated. The significant MRAA during the Full and Free conditions indicated effective external and internal motor response preparation. In the absence of specific motor preparation (None, a posterior alpha power decrease (event-related desynchronization, ERD dominated, reflecting the main engagement of attentional resources. In Full and Free motor preparation, posterior alpha ERD was accompanied by a midparietal alpha power increase (event-related synchronization, ERS, suggesting a concomitant inhibition of task-irrelevant visual activity. In both Full and Free motor preparation, analysis of alpha power according to MRAA amplitude revealed two types of functional activation patterns: 1 a motor alpha pattern, with predominantly midparietal alpha ERS and large MRAA corresponding to lateralized motor activation/visual inhibition and 2 an attentional alpha pattern, with dominating right posterior alpha ERD and small MRAA reflecting visuospatial attention. The present results suggest that alpha oscillatory patterns do not resolve the selection mode of action, but rather distinguish separate functional strategies of motor preparation. 

Analyzing power spectral of electroencephalogram (EEG) signal to identify motoric arm movement using EMOTIV EPOC+

Science.gov (United States)

Bustomi, A.; Wijaya, S. K.; Prawito

2017-07-01

Rehabilitation of motoric dysfunction from the body becomes the main objective of developing Brain Computer Interface (BCI) technique, especially in the field of medical rehabilitation technology. BCI technology based on electrical activity of the brain, allow patient to be able to restore motoric disfunction of the body and help them to overcome the shortcomings mobility. In this study, EEG signal phenomenon was obtained from EMOTIV EPOC+, the signals were generated from the imagery of lifting arm, and look for any correlation between the imagery of motoric muscle movement against the recorded signals. The signals processing were done in the time-frequency domain, using Wavelet relative power (WRP) as feature extraction, and Support vector machine (SVM) as the classifier. In this study, it was obtained the result of maximum accuracy of 81.3 % using 8 channel (AF3, F7, F3, FC5, FC6, F4, F8, and AF4), 6 channel remaining on EMOTIV EPOC + does not contribute to the improvement of the accuracy of the classification system

The micro-step motor controller

International Nuclear Information System (INIS)

Hong, Kwang Pyo; Lee, Chang Hee; Moon, Myung Kook; Choi, Bung Hun; Choi, Young Hyun; Cheon, Jong Gu

2004-11-01

The developed micro-step motor controller can handle 4 axes stepping motor drivers simultaneously and provide high power bipolar driving mechanism with constant current mode. It can be easily controlled by manual key functions and the motor driving status is displayed by the front panel VFD. Due to the development of several kinds of communication and driving protocol, PC can operate even several micro-step motor controllers at once by multi-drop connection

No specific role for the manual motor system in processing the meanings of words related to the hand

Directory of Open Access Journals (Sweden)

Natasha ePostle

2013-02-01

Full Text Available The present study explored whether semantic and motor systems are functionally interwoven via the use of a dual-task paradigm. According to embodied language accounts that propose an automatic and necessary involvement of the motor system in conceptual processing, concurrent processing of hand-related information should interfere more with hand movements than processing of unrelated body-part (i.e., foot, mouth information. Across three experiments, 100 right-handed participants performed left- or right-hand tapping movements while repeatedly reading action words related to different body-parts, or different body-part names, in both aloud and silent conditions. Concurrent reading of single words related to specific body-parts, or the same words embedded in sentences differing in syntactic and phonological complexity (to manipulate context-relevant processing, and reading while viewing videos of the actions and body-parts described by the target words (to elicit visuomotor associations all interfered with right-hand but not left-hand tapping rate. However, this motor interference was not affected differentially by hand-related stimuli. Thus, the results provide no support for proposals that body-part specific resources in cortical motor systems are shared between overt manual movements and meaning-related processing of words related to the hand.

Advanced dc motor controller for battery-powered electric vehicles

Science.gov (United States)

Belsterling, C. A.

1981-01-01

A motor generation set is connected to run from the dc source and generate a voltage in the traction motor armature circuit that normally opposes the source voltage. The functional feasibility of the concept is demonstrated with tests on a Proof of Principle System. An analog computer simulation is developed, validated with the results of the tests, applied to predict the performance of a full scale Functional Model dc Controller. The results indicate high efficiencies over wide operating ranges and exceptional recovery of regenerated energy. The new machine integrates both motor and generator on a single two bearing shaft. The control strategy produces a controlled bidirectional plus or minus 48 volts dc output from the generator permitting full control of a 96 volt dc traction motor from a 48 volt battery, was designed to control a 20 hp traction motor. The controller weighs 63.5 kg (140 lb.) and has a peak efficiency of 90% in random driving modes and 96% during the SAE J 227a/D driving cycle.

Motor degradation prediction methods

Energy Technology Data Exchange (ETDEWEB)

Arnold, J.R.; Kelly, J.F.; Delzingaro, M.J.

1996-12-01

Motor Operated Valve (MOV) squirrel cage AC motor rotors are susceptible to degradation under certain conditions. Premature failure can result due to high humidity/temperature environments, high running load conditions, extended periods at locked rotor conditions (i.e. > 15 seconds) or exceeding the motor`s duty cycle by frequent starts or multiple valve stroking. Exposure to high heat and moisture due to packing leaks, pressure seal ring leakage or other causes can significantly accelerate the degradation. ComEd and Liberty Technologies have worked together to provide and validate a non-intrusive method using motor power diagnostics to evaluate MOV rotor condition and predict failure. These techniques have provided a quick, low radiation dose method to evaluate inaccessible motors, identify degradation and allow scheduled replacement of motors prior to catastrophic failures.

Optimization analysis of propulsion motor control efficiency

Directory of Open Access Journals (Sweden)

CAI Qingnan

2017-12-01

Full Text Available [Objectives] This paper aims to strengthen the control effect of propulsion motors and decrease the energy used during actual control procedures.[Methods] Based on the traditional propulsion motor equivalence circuit, we increase the iron loss current component, introduce the definition of power matching ratio, calculate the highest efficiency of a motor at a given speed and discuss the flux corresponding to the power matching ratio with the highest efficiency. In the original motor vector efficiency optimization control module, an efficiency optimization control module is added so as to achieve motor efficiency optimization and energy conservation.[Results] MATLAB/Simulink simulation data shows that the efficiency optimization control method is suitable for most conditions. The operation efficiency of the improved motor model is significantly higher than that of the original motor model, and its dynamic performance is good.[Conclusions] Our motor efficiency optimization control method can be applied in engineering to achieve energy conservation.

Modelling of electrical power systems for power flow analysis

Energy Technology Data Exchange (ETDEWEB)

Cogo, Joao Roberto [Escola Federal de Engenharia de Itajuba, MG (Brazil)

1994-12-31

The industry systems in Brazil are responsible for a consumption of over 50% (fifty per cent) of the total electrical power generated: therefore, they are import loads in power flow studies, and their modeling should be as much the best. Usually, in power flow studies, the industry systems are modeled by taking the influence of the power (active and reactive) and of the current on the voltage into account. Since the inducting motors, within the industry systems, represent at least 50% (fifty per cent) of the power consumption, and a large part of them is oversize, it is proposed to represent the industry systems as a function of the characteristic of power on shaft versus voltage into account. Since the induction motors, within the industry systems, represent at least 50% (fifty per cent) of the power consumption, and a large part of them is oversized, it is proposed to represent the industry systems as a function of the characteristics of power on shaft versus voltage for the analysis of power systems, aiming a load flow study. Thereafter, a model of an equivalent motor which has a basis the typical performance curve of an induction motor is present. This model is obtained from empirical parameters, surveyed from a population of over 1000 motors. (author) 3 refs., 1 fig., 4 tabs.

dHb9 expressing larval motor neurons persist through metamorphosis to innervate adult-specific muscle targets and function in Drosophila eclosion.

Science.gov (United States)

Banerjee, Soumya; Toral, Marcus; Siefert, Matthew; Conway, David; Dorr, Meredith; Fernandes, Joyce

2016-12-01

The Drosophila larval nervous system is radically restructured during metamorphosis to produce adult specific neural circuits and behaviors. Genesis of new neurons, death of larval neurons and remodeling of those neurons that persistent collectively act to shape the adult nervous system. Here, we examine the fate of a subset of larval motor neurons during this restructuring process. We used a dHb9 reporter, in combination with the FLP/FRT system to individually identify abdominal motor neurons in the larval to adult transition using a combination of relative cell body location, axonal position, and muscle targets. We found that segment specific cell death of some dHb9 expressing motor neurons occurs throughout the metamorphosis period and continues into the post-eclosion period. Many dHb9 > GFP expressing neurons however persist in the two anterior hemisegments, A1 and A2, which have segment specific muscles required for eclosion while a smaller proportion also persist in A2-A5. Consistent with a functional requirement for these neurons, ablating them during the pupal period produces defects in adult eclosion. In adults, subsequent to the execution of eclosion behaviors, the NMJs of some of these neurons were found to be dismantled and their muscle targets degenerate. Our studies demonstrate a critical continuity of some larval motor neurons into adults and reveal that multiple aspects of motor neuron remodeling and plasticity that are essential for adult motor behaviors. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 76: 1387-1416, 2016. © 2016 Wiley Periodicals, Inc.

Investigation on a Power Coupling Steering System for Dual-Motor Drive Tracked Vehicles Based on Speed Control

Directory of Open Access Journals (Sweden)

Li Zhai

2017-08-01

Full Text Available Double-motor drive tracked vehicles (2MDTV are widely used in the tracked vehicle industry due to the development of electric vehicle drive systems. The aim of this paper is to solve the problem of insufficient propulsion motor torque in low-speed, small-radius steering and insufficient power in high-speed large-radius steering. In order to do this a new type of steering system with a coupling device is designed and a closed-loop control strategy based on speed is adopted to improve the lateral stability of the vehicle. The work done entails modeling and simulating the 2MDTV and the proposed control strategy in RecurDyn and Matlab/Simulink. The simulation results show that the 2MDTV with the coupling device outputs more torque and power in both steering cases compared to the 2MDTV without the coupling device, and the steering stability of the vehicle is improved by using the strategy based on speed.

Specific properties of the SI and SII somatosensory areas and their effects on motor control: a system neurophysiological study.

Science.gov (United States)

Friedrich, Julia; Mückschel, Moritz; Beste, Christian

2018-03-01

Sensorimotor integration is essential for successful motor control and the somatosensory modality has been shown to have strong effects on the execution of motor plans. The primary (SI) and the secondary somatosensory (SII) cortices are known to differ in their neuroanatomical connections to prefrontal areas, as well as in their involvement to encode cognitive aspects of tactile processing. Here, we ask whether the area-specific processing architecture or the structural neuroanatomical connections with prefrontal areas determine the efficacy of sensorimotor integration processes for motor control. In a system neurophysiological study including EEG signal decomposition (i.e., residue iteration decomposition, RIDE) and source localization, we investigated this question using vibrotactile stimuli optimized for SI or SII processing. The behavioral data show that when being triggered via the SI area, inhibitory control of motor processes is stronger as when being triggered via the SII area. On a neurophysiological level, these effects were reflected in the C-cluster as a result of a temporal decomposition of EEG data, indicating that the sensory processes affecting motor inhibition modulate the response selection level. These modulations were associated with a stronger activation of the right inferior frontal gyrus extending to the right middle frontal gyrus as parts of a network known to be involved in inhibitory motor control when response inhibition is triggered over SI. In addition, areas important for sensorimotor integration like the postcentral gyrus and superior parietal cortex showed activation differences. The data suggest that connection patterns are more important for sensorimotor integration and control than the more restricted area-specific processing architecture.

Effect of Asymmetric Layout of IGBT Modules on Reliability of Power Inverters in Motor Drive System

DEFF Research Database (Denmark)

Choi, Uimin; Vernica, Ionut; Blaabjerg, Frede

2018-01-01

of inverters are limited by the most stressed devices. However, generally common data is provided for all devices and this may cause improper design of the inverters in terms of power rating and lifetime. In this paper, the effect of an asymmetric layout of IGBT modules on the reliability of power inverters......An IGBT module has typically multiple power devices for some technical and cost advantages. This kind of configurations could have an asymmetric layout, which may lead to different thermal loadings and thereby lifetime difference of the power devices. Therefore, both the power rating and lifetime...... is studied based on a 3-phase motor drive application with a 600 V, 30 A, 3-phase transfer molded IGBT module. The thermal impedances of 6 IGBTs are investigated and its effect on the thermal loadings of power devices is studied under the given mission profile. Finally, their lifetimes are estimated...

Steady State Dynamic Operating Behavior of Universal Motor

Directory of Open Access Journals (Sweden)

Muhammad Khan Burdi

2015-01-01

Full Text Available A detailed investigation of the universal motor is developed and used for various dynamic steady state and transient operating conditions of loads. In the investigation, output torque, motor speed, input current, input/output power and efficiency are computed, compared and analyzed for different loads. While this paper discusses the steady-state behavior of the universal motor, another companion paper, ?Transient dynamic behavior of universal motor?, will discuss its transient behavior in detail. A non-linear generalized electric machine model of the motor is considered for the analysis. This study was essential to investigate effect of output load on input current, power, speed and efficiency of the motor during operations. Previously such investigation is not known

Variable current speed controller for eddy current motors

Science.gov (United States)

Gerth, H.L.; Bailey, J.M.; Casstevens, J.M.; Dixon, J.H.; Griffith, B.O.; Igou, R.E.

1982-03-12

A speed control system for eddy current motors is provided in which the current to the motor from a constant frequency power source is varied by comparing the actual motor speed signal with a setpoint speed signal to control the motor speed according to the selected setpoint speed. A three-phase variable voltage autotransformer is provided for controlling the voltage from a three-phase power supply. A corresponding plurality of current control resistors is provided in series with each phase of the autotransformer output connected to inputs of a three-phase motor. Each resistor is connected in parallel with a set of normally closed contacts of plurality of relays which are operated by control logic. A logic circuit compares the selected speed with the actual motor speed obtained from a digital tachometer monitoring the motor spindle speed and operated the relays to add or substract resistance equally in each phase of the motor input to vary the motor current to control the motor at the selected speed.

Multidisciplinary approach to converting power chair into motorized prone cart.

Science.gov (United States)

Brose, Steven W; Wali, Eisha

2014-01-01

Pressure ulcers remain a major source of morbidity and mortality in veterans with neurologic impairment. Management of pressure ulcers typically involves pressure relief over skin regions containing wounds, but this can lead to loss of mobility and independence when the wounds are located in regions that receive pressure from sitting. An innovative, low-cost, multidisciplinary effort was undertaken to maximize quality of life in a veteran with a thoracic-4 level complete spinal cord injury and a stage 4 ischial wound. The person's power wheelchair was converted into a motorized prone cart, allowing navigation of the Department of Veterans Affairs spinal cord injury hospital ward and improved socialization while relieving pressure on the wound. Physical and occupational therapy assisted with the reconfiguration of the power chair and verified safe transfers into the chair and driving of the device. Psychology verified positive psychosocial benefit, while nursing and physician services verified an absence of unwanted pain or skin injury resulting from use of the device. Further investigation of ways to apply this technique is warranted to improve the quality of life of persons with pressure ulcers.

Subcontract Report: Final Report on Assessment of Motor Technologies for Traction Drives of Hybrid and Electric Vehicles (Subcontract #4000080341)

Energy Technology Data Exchange (ETDEWEB)

Fezzler, Raymond [BIZTEK Consulting, Inc.

2011-03-01

Currently, interior permanent magnet (IPM) motors with rare-earth (RE) magnets are almost universally used for hybrid and electric vehicles (EVs) because of their superior properties, particularly power density. However, there is now a distinct possibility of limited supply or very high cost of RE magnets that could make IPM motors unavailable or too expensive. Because development of electric motors is a critical part of the U.S. Department of Energy (DOE) Advanced Power Electronics and Motors activity, DOE needs to determine which options should be investigated and what barriers should be addressed. Therefore, in order to provide a basis for deciding which research topics should be pursued, an assessment of various motor technologies was conducted to determine which, if any, is potentially capable of meeting FreedomCAR 2015 and 2020 targets. Highest priority was given to IPM, surface mounted permanent magnet (SPM), induction, and switched reluctance (SR) motors. Also of interest, but with lesser emphasis, were wheel motors, multiple-rotor motors, motors with external excitation, and several others that emerged from the assessment. Cost and power density (from a design perspective, the power density criterion translates to torque density) are emerging as the two most important properties of motors for traction drives in hybrid and EVs, although efficiency and specific power also are very important. The primary approach for this assessment involved interviews with original equipment manufacturers (OEMs), their suppliers, and other technical experts. For each technology, the following issues were discussed: (1) The current state-of-the-art performance and cost; (2) Recent trends in the technology; (3) Inherent characteristics of the motor - which ones limit the ability of the technology to meet the targets and which ones aid in meeting the target; (4) What research and development (R&D) would be needed to meet the targets; and (5) The potential for the technology to

Phrenic motor neuron adenosine 2A receptors elicit phrenic motor facilitation.

Science.gov (United States)

Seven, Yasin B; Perim, Raphael R; Hobson, Orinda R; Simon, Alec K; Tadjalli, Arash; Mitchell, Gordon S

2018-04-15

Although adenosine 2A (A 2A ) receptor activation triggers specific cell signalling cascades, the ensuing physiological outcomes depend on the specific cell type expressing these receptors. Cervical spinal adenosine 2A (A 2A ) receptor activation elicits a prolonged facilitation in phrenic nerve activity, which was nearly abolished following intrapleural A 2A receptor siRNA injections. A 2A receptor siRNA injections selectively knocked down A 2A receptors in cholera toxin B-subunit-identified phrenic motor neurons, sparing cervical non-phrenic motor neurons. Collectively, our results support the hypothesis that phrenic motor neurons express the A 2A receptors relevant to A 2A receptor-induced phrenic motor facilitation. Upregulation of A 2A receptor expression in the phrenic motor neurons per se may potentially be a useful approach to increase phrenic motor neuron excitability in conditions such as spinal cord injury. Cervical spinal adenosine 2A (A 2A ) receptor activation elicits a prolonged increase in phrenic nerve activity, an effect known as phrenic motor facilitation (pMF). The specific cervical spinal cells expressing the relevant A 2A receptors for pMF are unknown. This is an important question since the physiological outcome of A 2A receptor activation is highly cell type specific. Thus, we tested the hypothesis that the relevant A 2A receptors for pMF are expressed in phrenic motor neurons per se versus non-phrenic neurons of the cervical spinal cord. A 2A receptor immunostaining significantly colocalized with NeuN-positive neurons (89 ± 2%). Intrapleural siRNA injections were used to selectively knock down A 2A receptors in cholera toxin B-subunit-labelled phrenic motor neurons. A 2A receptor knock-down was verified by a ∼45% decrease in A 2A receptor immunoreactivity within phrenic motor neurons versus non-targeting siRNAs (siNT; P phrenic motor neurons. In rats that were anaesthetized, subjected to neuromuscular blockade and ventilated, p

Open-Ended Electric Motor

Science.gov (United States)

Gould, Mauri

1975-01-01

Presents complete instructions for assembling an electric motor which does not require large amounts of power to operate and which is inexpensive as well as reliable. Several open-ended experiments with the motor are included as well as information for obtaining a kit of parts and instructions. (BR)

Task-dependent activation of distinct fast and slow(er) motor pathways during motor imagery.

Science.gov (United States)

Keller, Martin; Taube, Wolfgang; Lauber, Benedikt

2018-02-22

Motor imagery and actual movements share overlapping activation of brain areas but little is known about task-specific activation of distinct motor pathways during mental simulation of movements. For real contractions, it was demonstrated that the slow(er) motor pathways are activated differently in ballistic compared to tonic contractions but it is unknown if this also holds true for imagined contractions. The aim of the present study was to assess the activity of fast and slow(er) motor pathways during mentally simulated movements of ballistic and tonic contractions. H-reflexes were conditioned with transcranial magnetic stimulation at different interstimulus intervals to assess the excitability of fast and slow(er) motor pathways during a) the execution of tonic and ballistic contractions, b) motor imagery of these contraction types, and c) at rest. In contrast to the fast motor pathways, the slow(er) pathways displayed a task-specific activation: for imagined ballistic as well as real ballistic contractions, the activation was reduced compared to rest whereas enhanced activation was found for imagined tonic and real tonic contractions. This study provides evidence that the excitability of fast and slow(er) motor pathways during motor imagery resembles the activation pattern observed during real contractions. The findings indicate that motor imagery results in task- and pathway-specific subliminal activation of distinct subsets of neurons in the primary motor cortex. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Development of a PLC modem for data transmission over a PWM power supply

Science.gov (United States)

Batard, Christophe; Ginot, Nicolas; Mannah, Marc Anthony; Millet, Christophe; Poitiers, Frédéric

2014-04-01

In variable-speed electrical drive and online conditioning monitoring, a feedback loop is required in order to transmit the sensor information from the motor to the controller close to the inverter. Additional cabling is used for signalling. This extra cabling has a significant cost and data transmission may not be reliable. Thus, the use of power line communication (PLC) technology to transmit data in motor drive application is quite interesting. The use of a PLC modem dedicated to the home network in a three-phase inverter-fed motor power cable does not work. Therefore, specific coupling interfaces are developed to transmit data through a pulse-width modulated power supply. Laboratory tests have shown that the couplers are operating properly. They ensure reliable data transmission in a motor drive application.

Nano-Magnets and Additive Manufacturing for Electric Motors

Science.gov (United States)

Misra, Ajay K.

2014-01-01

High power density is required for application of electric motors in hybrid electric propulsion. Potential path to achieve high power density in electric motors include advanced materials, lightweight thermal management, lightweight structural concepts, high power density power electronics, and advanced manufacturing. This presentation will focus on two key technologies for achieving high power density, advanced magnets and additive manufacturing. The maximum energy product in current magnets is reaching their theoretical limits as a result of material and process improvements. Future improvements in the maximum energy product for magnets can be achieved through development of nanocomposite magnets combining the hard magnetic phase and soft magnetic phase at the nanoscale level. The presentation will provide an overview of the current state of development for nanocomposite magnets and the future path for doubling the maximum energy product. The other part of the presentation will focus on the role of additive manufacturing in fabrication of high power density electric motors. The presentation will highlight the potential opportunities for applying additive manufacturing to fabricate electric motors.

Modular PM Motor Drives for Automotive Traction Applications

International Nuclear Information System (INIS)

Su, G.J.

2001-01-01

This paper presents modular permanent magnet (PM) motor drives for automotive traction applications. A partially modularized drive system consisting of a single PM motor and multiple inverters is described. The motor has multiple three-phase stator winding sets and each winding set is driven with a separate three-phase inverter module. A truly modularized inverter and motor configuration based on an axial-gap PM motor is then introduced, in which identical PM motor modules are mounted on a common shaft and each motor module is powered by a separate inverter module. The advantages of the modular approach for both inverter and motor include: (1) power rating scalability-one design meets different power requirements by simply stacking an adequate number of modules, thus avoiding redesigning and reducing the development cost, (2) increased fault tolerance, and (3) easy repairing. A prototype was constructed by using two inverters and an axial-gap PM motor with two sets of three-phase stat or windings, and it is used to assist the diesel engine in a hybrid electric vehicle converted from a Chevrolet Suburban. The effect of different pulse-width-modulation strategies for both motoring and regenerative modes on current control is analyzed. Torque and regenerative control algorithms are implemented with a digital signal processor. Analytical and initial testing results are included in the paper

A CSMP commutation model for design study of a brushless dc motor power conditioner for a cruise missile fin control actuator

Science.gov (United States)

MacMillan, P. N.

1985-06-01

Recent improvements in rare earth magnets have made it possible to construct strong, lightweight, high horsepower dc motors. This has occasioned a reassessment of electromechanical actuators as alternatives to comparable pneumatic and hydraulic systems for use as flight control actuators for tactical missiles. A dynamic equivalent circuit model for the analysis of a small four pole brushless dc motor fed by a transistorized power conditioner utilizing high speed switching power transistors as final elements is presented. The influence of electronic commutation on instantaneous dynamic motor performance is particularly demonstrated and good correlation between computer simulation and typical experimentally obtained performance data is achieved. The model is implemented in CSMP language and features more accurate air gap flux representation over previous work. Hall effect sensor rotor position feedback is simulated. Both constant and variable air gap flux is modeled and the variable flux model treats the flux as a fundamental and one harmonic.

Retrofitting adjustable speed drives for large induction motors

International Nuclear Information System (INIS)

Wuestefeld, M.R.; Merriam, C.H.; Porter, N.S.

2004-01-01

Adjustable speed drives (ASDs) are used in many power plants to control process flow by varying the speed of synchronous and induction motors. In applications where the flow requirements vary significantly, ASDs reduce energy and maintenance requirements when compared with drag valves, dampers or other methods to control flow. Until recently, high horsepower ASDs were not available for induction motors. However, advances in power electronics technology have demonstrated the reliability and cost effectiveness of ASDs for large horsepower induction motors. Emphasis on reducing operation and maintenance costs and increasing the capacity factor of nuclear power plants has led some utilities to consider replacing flow control devices in systems powered by large induction motors with ASDs. ASDs provide a high degree of reliability and significant energy savings in situations where full flow operation is not needed for a substantial part of the time. This paper describes the basic adjustable speed drive technologies available for large induction motor applications, ASD operating experience and retrofitting ASDs to replace the existing GE Boiling Water Reactor recirculation flow control system

A Hydraulic Motor-Alternator System for Ocean-Submersible Vehicles

Science.gov (United States)

Aintablian, Harry O.; Valdez, Thomas I.; Jones, Jack A.

2012-01-01

An ocean-submersible vehicle has been developed at JPL that moves back and forth between sea level and a depth of a few hundred meters. A liquid volumetric change at a pressure of 70 bars is created by means of thermal phase change. During vehicle ascent, the phase-change material (PCM) is melted by the circulation of warm water and thus pressure is increased. During vehicle descent, the PCM is cooled resulting in reduced pressure. This pressure change is used to generate electric power by means of a hydraulic pump that drives a permanent magnet (PM) alternator. The output energy of the alternator is stored in a rechargeable battery that powers an on-board computer, instrumentation and other peripherals.The focus of this paper is the performance evaluation of a specific hydraulic motor-alternator system. Experimental and theoretical efficiency data of the hydraulic motor and the alternator are presented. The results are used to evaluate the optimization of the hydraulic motor-alternator system. The integrated submersible vehicle was successfully operated in the Pacific Ocean near Hawaii. A brief overview of the actual test results is presented.

Energy efficient power electronic controller for a capacitor-run single-phase induction motor

International Nuclear Information System (INIS)

Saravana Ilango, G.; Samidurai, K.; Roykumar, M.; Thanushkodi, K.

2009-01-01

At present the speed control of a capacitor-run single-phase induction motor is being achieved by using triac based voltage regulators. This paper proposes a new scheme; an electronic transformer acts as a voltage regulator. Performance comparison is made between these two schemes in this paper. It is found that the proposed scheme has superior operating and performance characteristics. Experimental results show that apart from improvement in performance with respect to power factor and total harmonic distortion an appreciable amount of energy saving is also obtained in the electronic transformer based scheme.

Motor degradation prediction methods

International Nuclear Information System (INIS)

Arnold, J.R.; Kelly, J.F.; Delzingaro, M.J.

1996-01-01

Motor Operated Valve (MOV) squirrel cage AC motor rotors are susceptible to degradation under certain conditions. Premature failure can result due to high humidity/temperature environments, high running load conditions, extended periods at locked rotor conditions (i.e. > 15 seconds) or exceeding the motor's duty cycle by frequent starts or multiple valve stroking. Exposure to high heat and moisture due to packing leaks, pressure seal ring leakage or other causes can significantly accelerate the degradation. ComEd and Liberty Technologies have worked together to provide and validate a non-intrusive method using motor power diagnostics to evaluate MOV rotor condition and predict failure. These techniques have provided a quick, low radiation dose method to evaluate inaccessible motors, identify degradation and allow scheduled replacement of motors prior to catastrophic failures

Fleet wide motor asset management program

International Nuclear Information System (INIS)

Rosemeier, R.G.; Moxie, J.J.; Mendez, W.E.

2011-01-01

The Institute of Nuclear Power Operations (INPO) performed several studies concerning the effects of motor failures on US power production. Problems with aging and the lack of preventative maintenance were noted as major contributors to this production loss. Westinghouse has developed, and successfully utilized, a computer program to assist plants in the decision making process for maximizing the operational availability of their motor fleet. The program considers motors of a fleet as a single, critical to production asset, and aids the operator in decisions regarding the following: 1.) Purchase of spares. 2.) Rewind and refurbishment prioritization. 3.) Long-term budget forecasting. (author)

Evaluation of Functional Correlation of Task-Specific Muscle Synergies with Motor Performance in Patients Poststroke

Directory of Open Access Journals (Sweden)

Si Li

2017-07-01

Full Text Available The central nervous system produces movements by activating specifically programmed muscle synergies that are also altered with injuries in the brain, such as stroke. In this study, we hypothesize that there exists a positive correlation between task-specific muscle synergy and motor functions at joint and task levels in patients following stroke. The purpose here is to define and evaluate neurophysiological metrics based on task-specific muscle synergy for assessing motor functions in patients. A patient group of 10 subjects suffering from stroke and a control group of nine age-matched healthy subjects were recruited to participate in this study. Electromyography (EMG signals and movement kinematics were recorded in patients and control subjects while performing arm reaching tasks. Muscle synergies of individual patients were extracted off-line from EMG records of each patient, and a baseline pattern of muscle synergy was obtained from the pooled EMG data of all nine control subjects. Peak velocities and movement durations of each reaching movement were computed from measured kinematics. Similarity indices of matching components to those of the baseline synergy were defined by synergy vectors and time profiles, respectively, as well as by a combined similarity of vector and time profile. Results showed that pathological synergies of patients were altered from the characteristics of baseline synergy with missing components, or varied vector patterns and time profiles. The kinematic performance measured by peak velocities and movement durations was significantly poorer for the patient group than the control group. In patients, all three similarity indices were found to correlate significantly to the kinematics of movements for the reaching tasks. The correlation to the Fugl-Meyer score of arm was the highest with the vector index, the lowest with the time profile index, and in between with the combined index. These findings illustrate that the

Maximum Power Point Tracking for Brushless DC Motor-Driven Photovoltaic Pumping Systems Using a Hybrid ANFIS-FLOWER Pollination Optimization Algorithm

Directory of Open Access Journals (Sweden)

Neeraj Priyadarshi

2018-04-01

Full Text Available In this research paper, a hybrid Artificial Neural Network (ANN-Fuzzy Logic Control (FLC tuned Flower Pollination Algorithm (FPA as a Maximum Power Point Tracker (MPPT is employed to amend root mean square error (RMSE of photovoltaic (PV modeling. Moreover, Gaussian membership functions have been considered for fuzzy controller design. This paper interprets the Luo converter occupied brushless DC motor (BLDC-directed PV water pump application. Experimental responses certify the effectiveness of the suggested motor-pump system supporting diverse operating states. The Luo converter, a newly developed DC-DC converter, has high power density, better voltage gain transfer and superior output waveform and can track optimal power from PV modules. For BLDC speed control there is no extra circuitry, and phase current sensors are enforced for this scheme. The most recent attempt using adaptive neuro-fuzzy inference system (ANFIS-FPA-operated BLDC directed PV pump with advanced Luo converter, has not been formerly conferred.

Development of a smart type motor operated valve for nuclear power plants

Science.gov (United States)

Kim, Chang-Hwoi; Park, Joo-Hyun; Lee, Dong-young; Koo, In-Soo

2005-12-01

In this paper, the design concept of the smart type motor operator valve for nuclear power plant was described. The development objective of the smart valve is to achieve superior accuracy, long-term reliability, and ease of use. In this reasons, developed smart valve has fieldbus communication such as deviceNet and Profibus-DP, auto-tuning PID controller, self-diagnostics, and on-line calibration capabilities. And also, to achieve pressure, temperature, and flow control with internal PID controller, the pressure sensor and transmitter were included in this valve. And, temperature and flow signal acquisition port was prepared. The developed smart valve will be performed equipment qualification test such as environment, EMI/EMC, and vibration in Korea Test Lab. And, the valve performance is tested in a test loop which is located in Seoul National University Lab. To apply nuclear power plant, the software is being developed according to software life cycle. The developed software is verified by independent software V and V team. It is expected that the smart valve can be applied to an existing NPPs for replacing or to a new nuclear power plants. The design and fabrication of smart valve is now being processed.

Intense neutron source: high-voltage power supply specifications

International Nuclear Information System (INIS)

Riedel, A.A.

1980-08-01

This report explains the need for and sets forth the electrical, mechanical and safety specifications for a high-voltage power supply to be used with the intense neutron source. It contains sufficient information for a supplier to bid on such a power supply

Parkinson's Disease Subtypes Identified from Cluster Analysis of Motor and Non-motor Symptoms.

Science.gov (United States)

Mu, Jesse; Chaudhuri, Kallol R; Bielza, Concha; de Pedro-Cuesta, Jesus; Larrañaga, Pedro; Martinez-Martin, Pablo

2017-01-01

Parkinson's disease is now considered a complex, multi-peptide, central, and peripheral nervous system disorder with considerable clinical heterogeneity. Non-motor symptoms play a key role in the trajectory of Parkinson's disease, from prodromal premotor to end stages. To understand the clinical heterogeneity of Parkinson's disease, this study used cluster analysis to search for subtypes from a large, multi-center, international, and well-characterized cohort of Parkinson's disease patients across all motor stages, using a combination of cardinal motor features (bradykinesia, rigidity, tremor, axial signs) and, for the first time, specific validated rater-based non-motor symptom scales. Two independent international cohort studies were used: (a) the validation study of the Non-Motor Symptoms Scale ( n = 411) and (b) baseline data from the global Non-Motor International Longitudinal Study ( n = 540). k -means cluster analyses were performed on the non-motor and motor domains (domains clustering) and the 30 individual non-motor symptoms alone (symptoms clustering), and hierarchical agglomerative clustering was performed to group symptoms together. Four clusters are identified from the domains clustering supporting previous studies: mild, non-motor dominant, motor-dominant, and severe. In addition, six new smaller clusters are identified from the symptoms clustering, each characterized by clinically-relevant non-motor symptoms. The clusters identified in this study present statistical confirmation of the increasingly important role of non-motor symptoms (NMS) in Parkinson's disease heterogeneity and take steps toward subtype-specific treatment packages.

Motor of the future - superconducting

International Nuclear Information System (INIS)

Moen, Odd

2001-01-01

High-temperature superconductors count as the most innovative and future-oriented technology for electric motors. When these materials are used, the engine rating can be doubled and at the same time the losses halved while retaining the same size of construction. Siemens have recently developed a synchronous motor based on a high-temperature superconducting excitation winding. The rated power of the motor is 380 kW. The high-temperature superconductor that is used in this motor requires considerably less cooling outfit than low-temperature superconductors

Design of an HTS motor

Energy Technology Data Exchange (ETDEWEB)

Jiang, Y; Pei, R; Hong, Z; Jiang, Q; Coombs, T A [Cambridge University engineering Department, Trumpington Street, Cambridge CB2 1PZ (United Kingdom)], E-mail: yj222@cam.ac.uk

2008-02-01

This paper gives a detailed description of the design of a high temperature superconducting (HTS) motor. The stator of the motor consists of six air cored HTS racetrack windings, together with an iron shield. The rotor is made of 80 superconducting YBCO pucks, which can be magnetized and equates to a four-pole permanent magnet. The whole HTS motor is cooled by liquid nitrogen to 77K, and acts as a permanent magnet synchronous motor with the power rate of 15.7 kW.

Harmonic modeling of induction motors

Energy Technology Data Exchange (ETDEWEB)

Pedra, J.; Sainz, L.; Corcoles, F. [Department of Electrical Engineering, ETSEIB-UPC, Av. Diagonal 647, 08028 Barcelona (Spain)

2006-07-15

The paper proposes an induction motor model for the study of harmonic load flow in balanced and unbalanced conditions. The parameters of this model are obtained from motor manufacturer data and the positive- and negative-sequence equivalent circuits of the single- and double-cage models. An approximate harmonic model based on motor manufacturer data only is also proposed. In addition, the paper includes manufacturer data and the calculated parameters of 36 induction motors of different rated powers. This database is used to analyze the proposed models. (author)

Does practicing a skill with the expectation of teaching alter motor preparatory cortical dynamics?

Science.gov (United States)

Daou, Marcos; Lohse, Keith R; Miller, Matthew W

2018-05-01

Recent evidence suggests practicing a motor skill with the expectation of teaching it enhances learning by increasing information processing during motor preparation. However, the specific motor preparatory processes remain unknown. The present study sought to address this shortcoming by employing EEG to assess participants' motor preparatory processes while they completed a golf putting pretest, and then practiced putting with the expectation of (a) teaching another participant how to putt the next day (teach group, n = 30), or (b) being tested on their putting the next day (test group, n = 30). Participants' EEG during the 3-s prior to and 1-s after initiating putter movement was analyzed. All participants completed posttests 1 day after the practice session. The teach group exhibited better posttest performance (superior learning) relative to the test group, but no group differences in motor preparatory processing (EEG) emerged. However, participants in both groups exhibited linear decreases in both theta power at frontal midline and upper-alpha power over motor areas during putt initiation. These results suggest a decrease in working memory and action monitoring (frontal midline theta), and an increase in motor programming (motor upper-alpha) during putt initiation. Further, participants in both groups exhibited increased frontal midline theta from pretest to practice, but decreases in both upper motor-alpha and upper-alpha coherence between left/right temporal and motor planning regions. These results suggest participants utilized working memory and action monitoring to a greater extent during practice relative to pretest, while refining their motor programming and verbal-analytic/visuospatial involvement in motor programming. Copyright © 2018 Elsevier B.V. All rights reserved.

The influence of motor imagery on the learning of a fine hand motor skill

NARCIS (Netherlands)

Sobierajewicz, Jagna; Przekoracka-Krawczyk, Anna; Jaśkowski, Wojciech; Verwey, Willem B.; van der Lubbe, Rob

2017-01-01

Motor imagery has been argued to affect the acquisition of motor skills. The present study examined the specificity of motor imagery on the learning of a fine hand motor skill by employing a modified discrete sequence production task: the Go/NoGo DSP task. After an informative cue, a response

Aging of electric motors in nuclear power plants

International Nuclear Information System (INIS)

Subudhi, M.; Taylor, J.H.

1987-06-01

Motor degradation due to aging and service wear decreases reliability and increases the potential for failure during nuclear plant accident and post accident conditions. The impact of motor failures on plant safety is an important concern among the nuclear utilities and the government agency regulating this industry. Economic impacts, relating to plant availability and safety, as well as corrective maintenance, have prompted utilities to improve their maintenance programs to mitigate such aging effects. 2 refs., 3 figs

Design and Analysis of Multi-Phase BLDC Motors for Electric Vehicles

Directory of Open Access Journals (Sweden)

G. Boztas

2018-04-01

Full Text Available This paper presents a design and analysis of multi-phase brushless direct current (BLDC motor for electric vehicles (EV. In this work, hub-wheels having 110Nm, 900rpm rated values have been designed for the proposed EV. This EV can produce 440 Nm without using transmission, differential and other mechanical components which have very high losses due to the mechanical fraction. The motors to be used in the EV have been designed as 3-, 5- and 7-phase by Infolytica/Motor Solve Software to compare their performances at the same load conditions. The same rotor geometry has been utilized for the motors. However, slot numbers and dimensions of the stator have been determined by considering the motor phase number. Performance curves of phase-currents, output powers, torques, efficiencies and power factors have been presented for these motors at the same operating conditions. It can be possible to use lower power switches in motor drive system thanks to the phase current reduction since the phase currents decrease proportionally to motor phase number. This work shows that the multi-phase BLDC motors are a good alternative in order to obtain lower torque and lower power inverter structure than the 3-phase BLDC motors which are used as standard.

PS main supply: motor-generator set.

CERN Multimedia

Maximilien Brice

2002-01-01

In picture 04 the motor is on the right in the background and the main view is of the generator. The peak power in each PS cycle drawn from the generator, up to 96 MW, is taken from the rotational kinetic energy of the rotor (a heavy-weight of 80 tons), which makes the rotational speed drop by only a few percent. The motor replenishes the average power of 2 to 4 MW. Photo 05: The motor-generator set is serviced every year and, in particular, bearings and slip-rings are carefully checked. To the left is the motor with its slip-rings visible. It has been detached from the axle and moved to the side, so that the rotor can be removed from the huge generator, looming at the right.

Task-specific modulation of effective connectivity during two simple unimanual motor tasks: A 122-channel EEG study

DEFF Research Database (Denmark)

Herz, Damian M.; Christensen, Mark S.; Reck, Christiane

2012-01-01

Neural oscillations are thought to underlie coupling of spatially remote neurons and gating of information within the human sensorimotor system. Here we tested the hypothesis that different unimanual motor tasks are specifically associated with distinct patterns of oscillatory coupling in human...

Gravity Compensation Technique Uses Small dc Motor

Science.gov (United States)

Hollow, Richard

1988-01-01

Small dc servomotor powered by simple constant-current source and with suitable gearing used to cancel effect of gravity upon load. Lead-screw positioning system has load counterbalanced by small supplementary motor powered by constant current source. Motor lighter and more compact alternative to counterbalance. Used in variety of mechanical systems where load positioned or accelerated in vertical plane.

Effect of ITE and nozzle exit cone erosion on specific impulse of solid rocket motors

Science.gov (United States)

Smith-Kent, Randall; Ridder, Jeffrey P.; Loh, Hai-Tien; Abel, Ralph

1993-06-01

Specific impulse loss due to the use of a slowly eroding integral throat entrance, or a throat insert, with a faster eroding nozzle exit cone is studied. It is suggested that an oblique shock wave produced by step-off erosion results in loss of specific impulse. This is studied by use of a shock capturing CFD method. The shock loss predictions for first-stage Peacekeeper and Castor 25 motors are found to match the trends of the test data. This work suggests that a loss mechanism, previously unaccounted, should be considered in the specific impulse prediction procedure for nozzles with step-off exit cone erosion.

Synchronous motor with hybrid permanent magnets on the rotor.

Science.gov (United States)

Slusarek, Barbara; Kapelski, Dariusz; Antal, Ludwik; Zalas, Pawel; Gwoździewicz, Maciej

2014-07-10

Powder metallurgy allows designers of electric motors to implement new magnetic circuit structures. A relatively new concept is the use of a magnet system consisting of various types of magnets on one rotor, for example sintered and bonded magnets. This concept has been applied to the design and manufacture of the four-pole rotor of a synchronous motor with 400 W power and a rotational speed of 1500 rpm. In this motor, the stator of an asynchronous motor type Sh 71-4B is applied. The application of the new construction of the rotor resulted in an increase in motor efficiency and power factor compared to an asynchronous motor with the same volume.

Synchronous Motor with Hybrid Permanent Magnets on the Rotor

Directory of Open Access Journals (Sweden)

Barbara Slusarek

2014-07-01

Full Text Available Powder metallurgy allows designers of electric motors to implement new magnetic circuit structures. A relatively new concept is the use of a magnet system consisting of various types of magnets on one rotor, for example sintered and bonded magnets. This concept has been applied to the design and manufacture of the four-pole rotor of a synchronous motor with 400 W power and a rotational speed of 1500 rpm. In this motor, the stator of an asynchronous motor type Sh 71-4B is applied. The application of the new construction of the rotor resulted in an increase in motor efficiency and power factor compared to an asynchronous motor with the same volume.

Control Demonstration of Multiple Doubly-Fed Induction Motors for Hybrid Electric Propulsion

Science.gov (United States)

Sadey, David J.; Bodson, Marc; Csank, Jeffrey T.; Hunker, Keith R.; Theman, Casey J.; Taylor, Linda M.

2017-01-01

The Convergent Aeronautics Solutions (CAS) High Voltage-Hybrid Electric Propulsion (HVHEP) task was formulated to support the move into future hybrid-electric aircraft. The goal of this project is to develop a new AC power architecture to support the needs of higher efficiency and lower emissions. This proposed architecture will adopt the use of the doubly-fed induction machine (DFIM) for propulsor drive motor application.The Convergent Aeronautics Solutions (CAS) High Voltage-Hybrid Electric Propulsion (HVHEP) task was formulated to support the move into future hybrid-electric aircraft. The goal of this project is to develop a new AC power architecture to support the needs of higher efficiency and lower emissions. This proposed architecture will adopt the use of the doubly-fed induction machine (DFIM) for propulsor drive motor application. DFIMs are attractive for several reasons, including but not limited to the ability to self-start, ability to operate sub- and super-synchronously, and requiring only fractionally rated power converters on a per-unit basis depending on the required range of operation. The focus of this paper is based specifically on the presentation and analysis of a novel strategy which allows for independent operation of each of the aforementioned doubly-fed induction motors. This strategy includes synchronization, soft-start, and closed loop speed control of each motor as a means of controlling output thrust; be it concurrently or differentially. The demonstration of this strategy has recently been proven out on a low power test bed using fractional horsepower machines. Simulation and hardware test results are presented in the paper.

Development of Dual Power Multirotor System

Directory of Open Access Journals (Sweden)

Chin E. Lin

2017-01-01

Full Text Available Vertical take-off and landing (VTOL aircraft has good flight characteristics and system performance without runway. The multirotor system has been tried to expand into larger size for longer endurance or higher payload. But the motor power to endurance ratio has been limited. Due to the specific energy of gasoline being much higher than battery, introducing gasoline engine into multirotor system can be considered. This paper proposes a dual power multirotor system to combine a quadrotor using gasoline engines to provide major lift in shorter arm with another quadrotor using brushless DC motors to offer most controllable force with longer arm. System design, fabrication, and verification of the proposed dual power multirotor system development are presented. Preliminary flights have achieved 16 kg payload for long endurance flight. This is useful for various applications with advanced improvements.

Stochastic mechano-chemical kinetics of molecular motors: A multidisciplinary enterprise from a physicist’s perspective

Energy Technology Data Exchange (ETDEWEB)

Chowdhury, Debashish, E-mail: debchg@gmail.com

2013-08-01

A molecular motor is made of either a single macromolecule or a macromolecular complex. Just like their macroscopic counterparts, molecular motors “transduce” input energy into mechanical work. All the nano-motors considered here operate under isothermal conditions far from equilibrium. Moreover, one of the possible mechanisms of energy transduction, called Brownian ratchet, does not even have any macroscopic counterpart. But, molecular motor is not synonymous with Brownian ratchet; a large number of molecular motors execute a noisy power stroke, rather than operating as Brownian ratchet. We review not only the structural design and stochastic kinetics of individual single motors, but also their coordination, cooperation and competition as well as the assembly of multi-module motors in various intracellular kinetic processes. Although all the motors considered here execute mechanical movements, efficiency and power output are not necessarily good measures of performance of some motors. Among the intracellular nano-motors, we consider the porters, sliders and rowers, pistons and hooks, exporters, importers, packers and movers as well as those that also synthesize, manipulate and degrade “macromolecules of life”. We review mostly the quantitative models for the kinetics of these motors. We also describe several of those motor-driven intracellular stochastic processes for which quantitative models are yet to be developed. In part I, we discuss mainly the methodology and the generic models of various important classes of molecular motors. In part II, we review many specific examples emphasizing the unity of the basic mechanisms as well as diversity of operations arising from the differences in their detailed structure and kinetics. Multi-disciplinary research is presented here from the perspective of physicists.

Determinación IN-SITU del factor de potencia y la eficiencia de motores asincrónicos a cargas parciales; Induction motor power factor and efficiency IN-SITU determination under partial loads.

Directory of Open Access Journals (Sweden)

Percy Rafael Viego Felipe

2015-04-01

Full Text Available Los motores asincrónicos trifásicos no siempre operan a plena carga y por lo tanto, el factor de potencia y la eficiencia se ven afectados. Determinar estos valores a diferentes cargas, es la base para programas ahorro en la industria y los servicios. En este trabajo se presentan procedimientos para la estimación del factor de potencia y la eficiencia a cargas parciales, con una precisión acorde a los propósitos ingenieriles, baja invasividad y sin implicar para el usuario complejidades de equipamiento o de adquisición y procesamiento de datos. Se ofrecen distintas variantes para la estimación del factor de potencia y la eficiencia, según los datos con que se cuente. Se comparan los resultados de los métodos propuestos con la información de catálogos comerciales. Se realiza un análisis con motores de distinta potencia y velocidad, que demuestra que se logra buena precisión para los propósitos señalados. Three phase induction motors are rarely operating at full load and, in consequence, power factor and efficiency are affected. Determining these values for different partial loads is needed for energy saving programs in industrial and service enterprises. In this work, procedures are given for power factor and efficiency estimation at different loads. These procedures are low or not-invasive, have a good precision for engineering purposes, and do not require neither complex equipment nor complicated acquisition and processing data systems Different ways for estimating the before mentioned parameters, depending on the known data, are given. The results of the proposed procedures are compared with those of manufacturer catalogs. A comparative analysis considering motors of different output power and speed is done, and it shows that the results are enough accurate for the established purposes.

An Evaluation of Electric Motors for Ship Propulsion

Science.gov (United States)

2003-06-01

AIM). Permanent magnet motors are more power dense than a comparatively sized in- duction motor. The permanent magnet motor has been chosen to...study. They include the axial flux, the ra- dial flux, and the transverse flux permanent magnet motors . Each motor has its unique advantages...to be ideal for ship propulsion, work is ongoing to develop the PMSM for ship propulsion. Permanent magnet motors are expected to have significant

Losses in chopper-controlled DC series motors

Science.gov (United States)

Hamilton, H. B.

1982-01-01

Motors for electric vehicle (EV) applications must have different features than dc motors designed for industrial applications. The EV motor application is characterized by the following requirements: (1) the need for highest possible efficiency from light load to overload, for maximum EV range, (2) large short time overload capability (The ratio of peak to average power varies from 5/1 in heavy city traffic to 3/1 in suburban driving situations) and (3) operation from power supply voltage levels of 84 to 144 volts (probably 120 volts maximum). A test facility utilizing a dc generator as a substitute for a battery pack was designed and utilized. Criteria for the design of such a facility are presented. Two motors, differing in design detail, commercially available for EV use were tested. Losses measured are discussed, as are waves forms and their harmonic content, the measurements of resistance and inductance, EV motor/chopper application criteria, and motor design considerations.

Speed controller for an alternating - current motor

International Nuclear Information System (INIS)

Bolie, V.W.

1984-01-01

A controller for a multi-phase ac motor that is subject to a large inertial load, e.g. an induction motor driving a heavy spinning rotor of a neutron chopper that must be rotated in phase-locked synchronism with a reference pulse train that is representative of an ac power supply signal Esub(L) having a meandering line frequency, includes a sensor which provides a feedback pulse train representative of the actual speed of the motor which is compared (by counting clock pulses between feedback pulses) with a reference clock signal in a computing unit to provide a motor control signal Esub(c). The motor control signal is a weighted linear sum of a speed error signal, a phase error signal, and a drift error signal, the magnitudes of which are recalculated and updated with each revolution of the motor shaft. The speed error signal is constant for large speed errors but highly sensitive to small speed errors. The stator windings of the motor are driven by variable-frequency power amplifiers which are controlled by the motor control signal Esub(c) via PROMs which store digital representations of sine and cosine waveforms in quadrature. (author)

RATING CHANGES INTRODUCED IN SOME CHARACTERISTIC MORPHOLOGICAL AND BASIC-SPECIFIC MOTOR SKILLS TO YOUNG ACTIVE AND INACTIVE BASKETBALL PLAYERS

OpenAIRE

Qazim Elshani; Hazir Salihu

2016-01-01

The experiment deals with young people aged 13-14 years, male. Basketball team active and inactive, active group in addition to regular classes; they also practice basketball in clubs within the city. The experiment contains a total of eight morphological variables; five variables are the basic motor tests, while three tests of motor skills, situational. In this research, it applied test method T-group basketball between active and inactive, and morphological variables of specific movement sk...

Age-specific activation of cerebral areas in motor imagery - a fMRI study

Energy Technology Data Exchange (ETDEWEB)

Wang, Li [Chongqing University, Key Laboratory of Biorheological Science and Technology of Ministry of Education, Bioengineering College, Chongqing (China); Third Military Medical University, Department of Medical Image, College of Biomedical Engineering, Chongqing (China); Qiu, Mingguo; Zhang, Jingna; Zhang, Ye; Sang, Linqiong [Third Military Medical University, Department of Medical Image, College of Biomedical Engineering, Chongqing (China); Liu, Chen; Yang, Jun [Third Military Medical University, Department of Radiology, Southwest Hospital, Chongqing (China); Yan, Rubing [Third Military Medical University, Department of Rehabilitation, Southwest Hospital, Chongqing (China); Zheng, Xiaolin [Chongqing University, Key Laboratory of Biorheological Science and Technology of Ministry of Education, Bioengineering College, Chongqing (China)

2014-04-15

The objectives of this study were to study the age-specific activation patterns of cerebral areas during motor execution (ME) and motor imaging (MI) of the upper extremities and to discuss the age-related neural mechanisms associated with ME or MI. The functional magnetic resonance imaging technique was used to monitor the pattern and intensity of brain activation during the ME and MI of the upper extremities in 20 elderly (>50 years) and 19 young healthy subjects (<25 years). No major differences were identified regarding the activated brain areas during ME or MI between the two groups; however, a minor difference was noted. The intensity of the activated brain area during ME was stronger in the older group than in the younger group, while the results with MI were the opposite. The posterior central gyrus and supplementary motor area during MI were more active in the younger group than in the older group. The putamen, lingual, and so on demonstrated stronger activation during dominant hand MI in the older group. The results of this study revealed that the brain structure was altered and that neuronal activity was attenuated with age, and the cerebral cortex and subcortical tissues were found to be over-activated to achieve the same level of ME and MI, indicating that the activating effects of the left hemisphere enhanced with age, whereas the inhibitory effects declined during ME, and activation of the right hemisphere became more difficult during MI. (orig.)

Age-specific activation of cerebral areas in motor imagery - a fMRI study

International Nuclear Information System (INIS)

Wang, Li; Qiu, Mingguo; Zhang, Jingna; Zhang, Ye; Sang, Linqiong; Liu, Chen; Yang, Jun; Yan, Rubing; Zheng, Xiaolin

2014-01-01

The objectives of this study were to study the age-specific activation patterns of cerebral areas during motor execution (ME) and motor imaging (MI) of the upper extremities and to discuss the age-related neural mechanisms associated with ME or MI. The functional magnetic resonance imaging technique was used to monitor the pattern and intensity of brain activation during the ME and MI of the upper extremities in 20 elderly (>50 years) and 19 young healthy subjects (<25 years). No major differences were identified regarding the activated brain areas during ME or MI between the two groups; however, a minor difference was noted. The intensity of the activated brain area during ME was stronger in the older group than in the younger group, while the results with MI were the opposite. The posterior central gyrus and supplementary motor area during MI were more active in the younger group than in the older group. The putamen, lingual, and so on demonstrated stronger activation during dominant hand MI in the older group. The results of this study revealed that the brain structure was altered and that neuronal activity was attenuated with age, and the cerebral cortex and subcortical tissues were found to be over-activated to achieve the same level of ME and MI, indicating that the activating effects of the left hemisphere enhanced with age, whereas the inhibitory effects declined during ME, and activation of the right hemisphere became more difficult during MI. (orig.)

Control Of Stepper Motor Movement By DC Voltage

International Nuclear Information System (INIS)

Gayani, Didi; Margono; Indasah, Iin; Sugito

2000-01-01

Instrumentation for controlling the power of reactor of TRIGA Mark II uses the stepper motor to move the control rod of neutron absorbers. The direction and speed of control rod movement are determined by the polarity and the amplitude of DC voltage as an error signal that is the difference of set point of power and the power of being measured on the control system. The unit of stepper motor controller of reactor instrumentation of TRIGA Mark II uses patent module of trade Mark of Vexta, USA. In this chance, the electronic circuit is made to function as the control of stepper motor movement by using the DC voltage to anticipate the problem may be faced in case of repair and maintenance of reactor instrumentation. As a result of experiment, it is stated that the control of motor movement by using DC voltage is performed into 2 stages. First, by making the oscillator that is proportional to the positive DC voltage. Secondly, by making the translator to translate the oscillator signal to be a logic pattern for controlling the movement of stepper motor. Translator and motor driver are made by using the L297 and L298 as a pair of stepper motor controller of SGS T HOMSON

Motor cortex is required for learning but not executing a motor skill

Science.gov (United States)

Kawai, Risa; Markman, Timothy; Poddar, Rajesh; Ko, Raymond; Fantana, Antoniu; Dhawale, Ashesh; Kampff, Adam R.; Ölveczky, Bence P.

2018-01-01

Motor cortex is widely believed to underlie the acquisition and execution of motor skills, yet its contributions to these processes are not fully understood. One reason is that studies on motor skills often conflate motor cortex’s established role in dexterous control with roles in learning and producing task-specific motor sequences. To dissociate these aspects, we developed a motor task for rats that trains spatiotemporally precise movement patterns without requirements for dexterity. Remarkably, motor cortex lesions had no discernible effect on the acquired skills, which were expressed in their distinct pre-lesion forms on the very first day of post-lesion training. Motor cortex lesions prior to training, however, rendered rats unable to acquire the stereotyped motor sequences required for the task. These results suggest a remarkable capacity of subcortical motor circuits to execute learned skills and a previously unappreciated role for motor cortex in ‘tutoring’ these circuits during learning. PMID:25892304

Neuron-specific caveolin-1 overexpression improves motor function and preserves memory in mice subjected to brain trauma.

Science.gov (United States)

Egawa, Junji; Schilling, Jan M; Cui, Weihua; Posadas, Edmund; Sawada, Atsushi; Alas, Basheer; Zemljic-Harpf, Alice E; Fannon-Pavlich, McKenzie J; Mandyam, Chitra D; Roth, David M; Patel, Hemal H; Patel, Piyush M; Head, Brian P

2017-08-01

Studies in vitro and in vivo demonstrate that membrane/lipid rafts and caveolin (Cav) organize progrowth receptors, and, when overexpressed specifically in neurons, Cav-1 augments neuronal signaling and growth and improves cognitive function in adult and aged mice; however, whether neuronal Cav-1 overexpression can preserve motor and cognitive function in the brain trauma setting is unknown. Here, we generated a neuron-targeted Cav-1-overexpressing transgenic (Tg) mouse [synapsin-driven Cav-1 (SynCav1 Tg)] and subjected it to a controlled cortical impact model of brain trauma and measured biochemical, anatomic, and behavioral changes. SynCav1 Tg mice exhibited increased hippocampal expression of Cav-1 and membrane/lipid raft localization of postsynaptic density protein 95, NMDA receptor, and tropomyosin receptor kinase B. When subjected to a controlled cortical impact, SynCav1 Tg mice demonstrated preserved hippocampus-dependent fear learning and memory, improved motor function recovery, and decreased brain lesion volume compared with wild-type controls. Neuron-targeted overexpression of Cav-1 in the adult brain prevents hippocampus-dependent learning and memory deficits, restores motor function after brain trauma, and decreases brain lesion size induced by trauma. Our findings demonstrate that neuron-targeted Cav-1 can be used as a novel therapeutic strategy to restore brain function and prevent trauma-associated maladaptive plasticity.-Egawa, J., Schilling, J. M., Cui, W., Posadas, E., Sawada, A., Alas, B., Zemljic-Harpf, A. E., Fannon-Pavlich, M. J., Mandyam, C. D., Roth, D. M., Patel, H. H., Patel, P. M., Head, B. P. Neuron-specific caveolin-1 overexpression improves motor function and preserves memory in mice subjected to brain trauma. © FASEB.

Equivalent mechanical parameters of oscillating rotary motors used in transport equipment

Directory of Open Access Journals (Sweden)

A. Andziulis

2006-12-01

Full Text Available In various appliances and equipment of sundry transport means there is a lot of diverse mechanisms of periodical movement. So, the various piston or membrane pumps of fuel feeding and lubrication systems, circulation pumps, air and refrigerating coolant compressors, etc. are the typical examples of innovative and well promising application of the oscillating motors. In these cases the moving part of a motor can be directly connected to the working body of driven mechanism without the additional gears. Consequently, the drive can be simplified in design and improved in efficiency and reliability. Application of the oscillating rotary motors, if used in the aforesaid devices, strictly depends on specific properties of mechanical system of a motor aggregated with the driven mechanism and considered as the one-piece unit on the whole. So, this study analyses how the properties of mechanical system, comprised of two moving parts interconnected eccentrically or centrically, can be evaluated by the equivalent rotational inertia, equivalent mass and by equivalent mechanical power factor which, in turn, determine the operating characteristics and basic possibilities of the motor.

RELATIONS BETWEEN GENERAL MOTOR SKILLS AND HANDBALL SPECIFIC TEST "BALL SLALOM" IN STUDENTS OF THE IV GRADE OF PRIMARY SCHOOL

Directory of Open Access Journals (Sweden)

Dragan Branković

2012-09-01

Full Text Available Teaching physical education and physical training of children, should be appropriate to their age abilities and needs. Acquire the diversified movement experience is a priority of physical education in junior school age. Students fourth grade of primary school - age 10-11 years, in the sensitive period for developing coordination and speed capabilities. Sports game handball and mode of the game "mini-handball", which is adapted to students age abilities and spatial characteristics of the majority of primary schools, abundant with various tasks, specifically dominated by natural forms of movement - running, jumping, throwing. Therefore, handball has a significant role in solving the tasks of physical education. The specific motor tests and relations with the general motor skills are particularly important for continuous monitoring of motor development of children. The survey was conducted on 79 boys fourth grade of primary school who participated in the electoral sport of handball in the regular physical education classes. The results of the handball test "ball slalom" and its relation with general motor skills of students fourth grade of primary school, should contribute to the perception of the value of handball as the content of physical education, but also to contribute to the selection and forecast performance of children in handball.

46 CFR 183.320 - Generators and motors.

Science.gov (United States)

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Generators and motors. 183.320 Section 183.320 Shipping...) ELECTRICAL INSTALLATION Power Sources and Distribution Systems § 183.320 Generators and motors. (a) Each generator and motor must be: (1) In a location that is accessible, adequately ventilated, and as dry as...

Altered neuronal activities in the motor cortex with impaired motor performance in adult rats observed after infusion of cerebrospinal fluid from amyotrophic lateral sclerosis patients.

Science.gov (United States)

Sankaranarayani, R; Nalini, A; Rao Laxmi, T; Raju, T R

2010-01-05

Although definite evidences are available to state that, neuronal activity is a prime determinant of animal behavior, the specific relationship between local field potentials of the motor cortex after intervention with CSF from human patients and animal behavior have remained opaque. The present study has investigated whether cerebrospinal fluid from sporadic amyotrophic lateral sclerosis (sALS) patients could disrupt neuronal activity of the motor cortex, which could be associated with disturbances in the motor performance of adult rats. CSF from ALS patients (ALS-CSF) was infused into the lateral ventricle of Wistar rats. After 24h, the impact of ALS-CSF on the local field potentials (LFPs) of the motor cortex and on the motor behavior of animals were examined. The results indicate that ALS-CSF produced a bivariate distribution on the relative power values of the LFPs of the motor cortex 24h following infusion. However, the behavioral results did not show bimodality, instead showed consistent decrease in motor performance: on rotarod and grip strength meter. The neuronal activity of the motor cortex negatively correlated with the duration of ALS symptoms at the time of lumbar puncture. Although the effect of ALS-CSF was more pronounced at 24h following infusion, the changes observed in LFPs and motor performance appeared to revert to baseline values at later time points of testing. In the current study, we have shown that, ALS-CSF has the potential to perturb neuronal activity of the rat motor cortex which was associated with poor performance on motor function tests.

Simulation and performance of brushless dc motor actuators

Science.gov (United States)

Gerba, A., Jr.

1985-12-01

The simulation model for a Brushless D.C. Motor and the associated commutation power conditioner transistor model are presented. The necessary conditions for maximum power output while operating at steady-state speed and sinusoidally distributed air-gap flux are developed. Comparison of simulated model with the measured performance of a typical motor are done both on time response waveforms and on average performance characteristics. These preliminary results indicate good agreement. Plans for model improvement and testing of a motor-driven positioning device for model evaluation are outlined.

Evaluation and comparison of electric propulsion motors for submarines

OpenAIRE

Harbour, Joel P.

2001-01-01

CIVINS (Civilian Institutions) Thesis document The Navy has announced its conviction to make its warships run on electric power through the decision to make its newest line of destroyers propelled with an electric propulsion system. Several ship construction firms and electric motor manufacturers are thus striving to develop enabling technology, including high power density motors. The purpose of this thesis is to evaluate some of the proposed motor designs for use in a submarine. Permanen...

Design for Reliability and Robustness Tool Platform for Power Electronic Systems – Study Case on Motor Drive Applications

DEFF Research Database (Denmark)

Vernica, Ionut; Wang, Huai; Blaabjerg, Frede

2018-01-01

conventional approach, mainly based on failure statistics from the field, the reliability evaluation of the power devices is still a challenging task. In order to address the given problem, a MATLAB based reliability assessment tool has been developed. The Design for Reliability and Robustness (DfR2) tool...... allows the user to easily investigate the reliability performance of the power electronic components (or sub-systems) under given input mission profiles and operating conditions. The main concept of the tool and its framework are introduced, highlighting the reliability assessment procedure for power...... semiconductor devices. Finally, a motor drive application is implemented and the reliability performance of the power devices is investigated with the help of the DfR2 tool, and the resulting reliability metrics are presented....

Chemical and radiochemical specifications - PWR power plants

International Nuclear Information System (INIS)

Stutzmann, A.

1997-01-01

Published by EDF this document gives the chemical specifications of the PWR (Pressurized Water Reactor) nuclear power plants. Among the chemical parameters, some have to be respected for the safety. These parameters are listed in the STE (Technical Specifications of Exploitation). The values to respect, the analysis frequencies and the time states of possible drops are noticed in this document with the motion STE under the concerned parameter. (A.L.B.)

Comparative Analysis of Miniature Internal Combustion Engine and Electric Motor for UAV Propulsion

Science.gov (United States)

Chiclana, Branden Mark

This thesis compares the performance of an engine/fuel tank based propulsion system to a motor/battery based propulsion system of equal total mass. The results show that the endurance of the engine/fuel system at the same thrust output is approximately 5 times greater than that of the motor/battery system. This is a direct result of the fact that the specific energy of the fuel is 20 times that of the lithium-polymer batteries used to power the motor. A method is also developed to account for the additional benefits of fuel consumption (and hence weight reduction) over the course of the flight. Accounting for this effect can increase endurance exponentially. Taken together, the results also demonstrate the dramatic performance improvements that are possible simply by replacing motor/battery systems with engine/fuel systems on small unmanned air vehicles.

Consideration on A.C. electric motor subjected to thermal and radiation accelerated ageing

International Nuclear Information System (INIS)

Doina, Segarceanu; Geambau, C.

2001-01-01

In the containment building of a nuclear reactor there are many types of equipment, such as motors, valve and transducers. Electric motors used in nuclear power stations operate under specific environmental conditions. These conditions are determinate by temperature, humidity, pressure, radiation and they may be normal conditions in service, or may be accident conditions occur during the postulated LOCA event. The testing of electric motors capability to meet and exceed the required performances under specific operating environmental conditions all along its operating life implies the performing of a sequence of tests in which the environmental conditions are simulated in a accelerated manner followed by accident simulation tests. Simulating the ageing position of the test sequence is more difficult because of the problem of extrapolating the results of short term accelerated laboratory experiments to the long term exposure (up to 30 years) that actually occur in a nuclear plant. Thermally induced ageing is the most frequently used ageing stress and also the most easily. The insulated system of a motor ageing under the influence of temperature and high - energy radiation can suffer important changes in its electro-insulating properties. Thus, by way of accelerated ageing motors are brought under conditions equivalent to those at the end of their service life, in a relatively short time. Accelerated ageing enables a shorting of electric motor performance evaluation time. (author)

Thermal loss of life and load-carrying capacity of marine induction motors

International Nuclear Information System (INIS)

Gnacinski, P.

2014-01-01

Highlights: • The effect of voltage quality on induction motors is investigated. • Power quality significantly affects machine lifetime and load-carrying capacity. • Permissible load levels for induction motors are proposed. - Abstract: This work deals with the effect of a lowered voltage quality on the thermal loss of life and load-carrying capacity of marine induction cage machines. Results of experimental investigations and computer calculations are presented for two low power induction motors with different properties. One of them has a comparatively strongly-saturated magnetic circuit and is especially exposed to the risk of overheating under overvoltage. The other machine has a comparatively weakly-saturated magnetic circuit, and is especially sensitive to undervoltage. The induction motor lifetime expectancy is also estimated on the basis of the temperature coefficient of power quality, whose value is proportional to the windings temperature rise in induction motors especially sensitive to various power quality disturbances. The dependence of the temperature coefficient of power quality and permissible loads for induction motors supplied with voltages of lowered quality is proposed

Software for optimal selection of places for installation of balancing devices in 0,4 kV electric power systems loaded with electric motors

Directory of Open Access Journals (Sweden)

Romanova Victoria

2017-01-01

Full Text Available This publication considers the issues of development of the software program for designing of 0,4 kV power supply systems with motor-actuated load under voltage unsymmetry conditions (using the example of the Trans-Baikal Territory. Voltage unsymmetry is practically constant phenomenon in the electric power networks of different voltage types. Voltage unsymmetry effects significantly the electric power consumers, including the supply mains itself. It has especially negative impact on the electrical equipment operation process and its lifetime. The urgency of the problem is confirmed by multiple research on the same topic and by significant number of damages suffered by the electric power consumers staying in service (especially in the Trans-Baikal Territory and in the Far-East regions. Voltage unsymmetry causes economic loss and reduction of the electromagnetic interference value by the voltage unsymmetry coefficient in negative-phase sequence (K2U gives inevitable economic effect accordingly. However, the payback period for the activities aimed at reduction of electromagnetic interference, will vary from some months to several years. The more accurate value of the payback period may be obtained using the developed software program. The developed software design program is implemented by means of the programming language C# in Microsoft Visual Studio environment, using the built-in cross-platform database SQLite. The software program shall allow making quick and accurate calculation of the power losses, to determine the economic feasibility of provision special measures for removal of the voltage unsymmetry, for determination of optimal application and location of the balancing devices. The software implementation in power systems loaded with electric motors will improve reliability and efficiency of asynchronous motors. The software is of interest for developers of projects on power supply systems for regions with non-linear loads.

Ventajas de los motores de flujo axial

Directory of Open Access Journals (Sweden)

Alberto M Basanta Otero

2011-03-01

Full Text Available Es importante conocer sobre una familia de motores que a diferencia de los convencionales o tradicionales no presentanun flujo rotatorio radial, denominados motores de flujo axial. Dichos motores presentan altos valores de par motriz abajas velocidades, una alta eficiencia y alta densidad de potencia. Este trabajo constituye un breve análisis dealgunos motores de la referencia bibliográfica.  Is important to know about a family of motors that at difference whit the traditional, don't have a rotator radial flux,called, axial flux motors. These motors have high torque for low speed, high efficiency and high power density. Thiswork is a brief analysis of several motors of the bibliographic references.

Relationship of striatal 99Tcm-TRODAT-1 specific uptake and motor's severity in patients with Parkinson's disease

International Nuclear Information System (INIS)

Bian Yanzhu; Liu Huang; Feng Jue; Wei Qiang; Li Jinfu; Liu Guozhang

2004-01-01

Objective: To investigate the relationship of striatal 99 Tc m -2β-((N, N'-bis (2-mercap-toethyl) ethylene diamino) methyl), 3β-(4-chlorophenyl) tropane, ( 99 Tc m -TRODAT-1) specific uptake values (SUVs) and motor's severity in patients with Parkinson's disease (PD). Methods: 35 patients with PD were examined by 99 Tc m -TRODAT-1 SPECT dopamine transporter brain imaging. The SUVs of the striatum and its subregions, including the putamen and caudate nucleus, were calculated by semi-quantity region of interest (ROI) technique with the radiation ratios of target/cerebellum. Motor's severity of PD was measured by Unified Parkinson's Disease Rating Scale (UPDRS). Motor UPDRS scores were divided into four subscales, bradykinesia scores, rigidity scores, postural instability scores and tremor scores. Results: SUVs of putamen correlated best with the motor UPDRS scores(r=-0.846, P<0.001), followed by that of striatum and caudate nucleus. Among the four major clinical signs of PD, the bradykinesia scores (X1) correlated best with SUVs of putamen(r=-0.858, P<0.001), followed by rigidity scores (X2) and postural instability scores. There was no significant correlation between tremor scores and SUVs of putamen (Y). A regression equation (Y=2.345-0.0418 X1-0.0580 X2) was founded by stepwise multiple linear regression analysis. Conclusions: The SUVs of striatum (especially SUVs of putamen) was a useful marker to evaluate the motor's severity of PD and monitor the progression of PD. (authors)

Motor cortex is required for learning but not for executing a motor skill.

Science.gov (United States)

Kawai, Risa; Markman, Timothy; Poddar, Rajesh; Ko, Raymond; Fantana, Antoniu L; Dhawale, Ashesh K; Kampff, Adam R; Ölveczky, Bence P

2015-05-06

Motor cortex is widely believed to underlie the acquisition and execution of motor skills, but its contributions to these processes are not fully understood. One reason is that studies on motor skills often conflate motor cortex's established role in dexterous control with roles in learning and producing task-specific motor sequences. To dissociate these aspects, we developed a motor task for rats that trains spatiotemporally precise movement patterns without requirements for dexterity. Remarkably, motor cortex lesions had no discernible effect on the acquired skills, which were expressed in their distinct pre-lesion forms on the very first day of post-lesion training. Motor cortex lesions prior to training, however, rendered rats unable to acquire the stereotyped motor sequences required for the task. These results suggest a remarkable capacity of subcortical motor circuits to execute learned skills and a previously unappreciated role for motor cortex in "tutoring" these circuits during learning. Copyright © 2015 Elsevier Inc. All rights reserved.

Neurons other than motor neurons in motor neuron disease.

Science.gov (United States)

Ruffoli, Riccardo; Biagioni, Francesca; Busceti, Carla L; Gaglione, Anderson; Ryskalin, Larisa; Gambardella, Stefano; Frati, Alessandro; Fornai, Francesco

2017-11-01

Amyotrophic lateral sclerosis (ALS) is typically defined by a loss of motor neurons in the central nervous system. Accordingly, morphological analysis for decades considered motor neurons (in the cortex, brainstem and spinal cord) as the neuronal population selectively involved in ALS. Similarly, this was considered the pathological marker to score disease severity ex vivo both in patients and experimental models. However, the concept of non-autonomous motor neuron death was used recently to indicate the need for additional cell types to produce motor neuron death in ALS. This means that motor neuron loss occurs only when they are connected with other cell types. This concept originally emphasized the need for resident glia as well as non-resident inflammatory cells. Nowadays, the additional role of neurons other than motor neurons emerged in the scenario to induce non-autonomous motor neuron death. In fact, in ALS neurons diverse from motor neurons are involved. These cells play multiple roles in ALS: (i) they participate in the chain of events to produce motor neuron loss; (ii) they may even degenerate more than and before motor neurons. In the present manuscript evidence about multi-neuronal involvement in ALS patients and experimental models is discussed. Specific sub-classes of neurons in the whole spinal cord are reported either to degenerate or to trigger neuronal degeneration, thus portraying ALS as a whole spinal cord disorder rather than a disease affecting motor neurons solely. This is associated with a novel concept in motor neuron disease which recruits abnormal mechanisms of cell to cell communication.

Actuation Using Piezoelectric Materials: Application in Augmenters, Energy Harvesters, and Motors

Science.gov (United States)

Hasenoehrl, Jennifer

2012-01-01

Piezoelectric actuators are used in many manipulation, movement, and mobility applications as well as transducers and sensors. When used at the resonance frequencies of the piezoelectric stack, the actuator performs at its maximum actuation capability. In this Space Grant internship, three applications of piezoelectric actuators were investigated including hammering augmenters of rotary drills, energy harvesters, and piezo-motors. The augmenter shows improved drill performance over rotation only. The energy harvesters rely on moving fluid to convert mechanical energy into electrical power. Specific designs allow the harvesters more freedom to move, which creates more power. The motor uses the linear movement of the actuator with a horn applied to the side of a rotor to create rotational motion. Friction inhibits this motion and is to be minimized for best performance. Tests and measurements were made during this internship to determine the requirements for optimal performance of the studied mechanisms and devices.

Efficiency Measurement Using a Motor-Dynamo Module

Science.gov (United States)

Ng, Pun-hon; Wong, Siu-ling; Mak, Se-yuen

2009-01-01

In this article, we describe a simple method which can be used to measure the efficiency of a low power dc motor, a motor-converted dynamo and a coupled motor-dynamo module as a function of the speed of rotation. The result can also be used to verify Faraday's law of electromagnetic induction. (Contains 1 table and 8 figures.)

DC Motor Drive with PFC Rectifier

Directory of Open Access Journals (Sweden)

Lascu Mihaela

2008-05-01

Full Text Available The goal of this work is to study theperformances of a hybrid controller used to controlDC Motor drive with a single-phase power factorcorrection rectifier. This study is made usingcomputer simulation (Simulink. The first part isdevoted to the control system of the DC Motors. Inthe second part, the design of the hybrid controllerwill be presented. The third part is the design ofthe fast response single-phase boost power factorcorrection rectifier. The last parts are devoted tosimulation and experimental results.

Effects of motor congruence on visual working memory.

Science.gov (United States)

Quak, Michel; Pecher, Diane; Zeelenberg, Rene

2014-10-01

Grounded-cognition theories suggest that memory shares processing resources with perception and action. The motor system could be used to help memorize visual objects. In two experiments, we tested the hypothesis that people use motor affordances to maintain object representations in working memory. Participants performed a working memory task on photographs of manipulable and nonmanipulable objects. The manipulable objects were objects that required either a precision grip (i.e., small items) or a power grip (i.e., large items) to use. A concurrent motor task that could be congruent or incongruent with the manipulable objects caused no difference in working memory performance relative to nonmanipulable objects. Moreover, the precision- or power-grip motor task did not affect memory performance on small and large items differently. These findings suggest that the motor system plays no part in visual working memory.

ANALYSIS OF DIFFERENCES BETWEEN BOYS ATTENDING A FOOTBALL SCHOOL AND THOS WHO DO NOT DO SPORT WITH SPECIFIC-MOTOR ABILITIES

Directory of Open Access Journals (Sweden)

Slavko Molnar

2010-09-01

Full Text Available The subject sample of 240 boys aged 7-14 was divided to two subsamples of 120 boys each (active participants of “ЯMR Vojvodina” football school since the age of 7, and boys involved in sports, who regularly attended classes of physical education at school. The sample was subjected to 11 tests for evaluation of specific–motor abilities. The purpose of this research was to determine whether there are or there are not any differences in specific- motor abilities of subjects of the same age depending whether they play any sport or not. Analysis of results processed by discriminative analysis showed that the boys who attended football school achieved much better results in tests for evaluation of specific motor abilities than the boys who did not. At the age of 7-8, the differences can be attributed to efficient selection rather than the program contents due to the fact that they are beginners, whereas at older ages, these differences, being even higher in boys doing sports, can be attributed to the effects of program contents in the football school.

Body-specific motor imagery of hand actions: neural evidence from right- and left-handers

Directory of Open Access Journals (Sweden)

Roel M Willems

2009-11-01

Full Text Available If motor imagery uses neural structures involved in action execution, then the neural correlates of imagining an action should differ between individuals who tend to execute the action differently. Here we report fMRI data showing that motor imagery is influenced by the way people habitually perform motor actions with their particular bodies; that is, motor imagery is ‘body-specific’ (Casasanto, 2009. During mental imagery for complex hand actions, activation of cortical areas involved in motor planning and execution was left-lateralized in right-handers but right-lateralized in left-handers. We conclude that motor imagery involves the generation of an action plan that is grounded in the participant’s motor habits, not just an abstract representation at the level of the action’s goal. People with different patterns of motor experience form correspondingly different neurocognitive representations of imagined actions.

Analisis Pengaturan Putaran Motor Satu Fasa dengan Parameter Frekuensi Menggunakan Power Simulator (PSIM)

OpenAIRE

Rasjid, Dwi Hadidjaja

2015-01-01

-The Setting of a single-phase motor rotation can be performed in various ways, such as by adjusting the frequency of the motor, the voltage, motor resistor or increasing the number of motor poles.By using astable oscillator circuit, setting a single-phase motor rotation frequency parameters can be done by setting the value variabel resistor. Thyristor trigger circuit can be used to control a single-phase motor rotation. Thyristor trigger phase angle changes, caused changes in the frequency, ...

Motor network structure and function are associated with motor performance in Huntington's disease.

Science.gov (United States)

Müller, Hans-Peter; Gorges, Martin; Grön, Georg; Kassubek, Jan; Landwehrmeyer, G Bernhard; Süßmuth, Sigurd D; Wolf, Robert Christian; Orth, Michael

2016-03-01

In Huntington's disease, the relationship of brain structure, brain function and clinical measures remains incompletely understood. We asked how sensory-motor network brain structure and neural activity relate to each other and to motor performance. Thirty-four early stage HD and 32 age- and sex-matched healthy control participants underwent structural magnetic resonance imaging (MRI), diffusion tensor, and intrinsic functional connectivity MRI. Diffusivity patterns were assessed in the cortico-spinal tract and the thalamus-somatosensory cortex tract. For the motor network connectivity analyses the dominant M1 motor cortex region and for the basal ganglia-thalamic network the thalamus were used as seeds. Region to region structural and functional connectivity was examined between thalamus and somatosensory cortex. Fractional anisotropy (FA) was higher in HD than controls in the basal ganglia, and lower in the external and internal capsule, in the thalamus, and in subcortical white matter. Between-group axial and radial diffusivity differences were more prominent than differences in FA, and correlated with motor performance. Within the motor network, the insula was less connected in HD than in controls, with the degree of connection correlating with motor scores. The basal ganglia-thalamic network's connectivity differed in the insula and basal ganglia. Tract specific white matter diffusivity and functional connectivity were not correlated. In HD sensory-motor white matter organization and functional connectivity in a motor network were independently associated with motor performance. The lack of tract-specific association of structure and function suggests that functional adaptation to structural loss differs between participants.

James Webb Space Telescope Deployment Brushless DC Motor Characteristics Analysis

Science.gov (United States)

Tran, Ahn N.

2016-01-01

A DC motor's performance is usually characterized by a series of tests, which are conducted by pass/fail criteria. In most cases, these tests are adequate to address the performance characteristics under environmental and loading effects with some uncertainties and decent power/torque margins. However, if the motor performance requirement is very stringent, a better understanding of the motor characteristics is required. The purpose of this paper is to establish a standard way to extract the torque components of the brushless motor and gear box characteristics of a high gear ratio geared motor from the composite geared motor testing and motor parameter measurement. These torque components include motor magnetic detent torque, Coulomb torque, viscous torque, windage torque, and gear tooth sliding torque. The Aerospace Corp bearing torque model and MPB torque models are used to predict the Coulomb torque of the motor rotor bearings and to model the viscous components. Gear tooth sliding friction torque is derived from the dynamo geared motor test data. With these torque data, the geared motor mechanical efficiency can be estimated and provide the overall performance of the geared motor versus several motor operating parameters such as speed, temperature, applied current, and transmitted power.

21 CFR 882.4370 - Pneumatic cranial drill motor.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Pneumatic cranial drill motor. 882.4370 Section 882.4370 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... drill motor. (a) Identification. A pneumatic cranial drill motor is a pneumatically operated power...

21 CFR 882.4360 - Electric cranial drill motor.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Electric cranial drill motor. 882.4360 Section 882...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4360 Electric cranial drill motor. (a) Identification. An electric cranial drill motor is an electrically operated power source used...

State-dependent spike and local field synchronization between motor cortex and substantia nigra in hemiparkinsonian rats.

Science.gov (United States)

Brazhnik, Elena; Cruz, Ana V; Avila, Irene; Wahba, Marian I; Novikov, Nikolay; Ilieva, Neda M; McCoy, Alex J; Gerber, Colin; Walters, Judith R

2012-06-06

Excessive beta frequency oscillatory and synchronized activity has been reported in the basal ganglia of parkinsonian patients and animal models of the disease. To gain insight into processes underlying this activity, this study explores relationships between oscillatory activity in motor cortex and basal ganglia output in behaving rats after dopamine cell lesion. During inattentive rest, 7 d after lesion, increases in motor cortex-substantia nigra pars reticulata (SNpr) coherence emerged in the 8-25 Hz range, with significant increases in local field potential (LFP) power in SNpr but not motor cortex. In contrast, during treadmill walking, marked increases in both motor cortex and SNpr LFP power, as well as coherence, emerged in the 25-40 Hz band with a peak frequency at 30-35 Hz. Spike-triggered waveform averages showed that 77% of SNpr neurons, 77% of putative cortical interneurons, and 44% of putative pyramidal neurons were significantly phase-locked to the increased cortical LFP activity in the 25-40 Hz range. Although the mean lag between cortical and SNpr LFPs fluctuated around zero, SNpr neurons phase-locked to cortical LFP oscillations fired, on average, 17 ms after synchronized spiking in motor cortex. High coherence between LFP oscillations in cortex and SNpr supports the view that cortical activity facilitates entrainment and synchronization of activity in basal ganglia after loss of dopamine. However, the dramatic increases in cortical power and relative timing of phase-locked spiking in these areas suggest that additional processes help shape the frequency-specific tuning of the basal ganglia-thalamocortical network during ongoing motor activity.

Relationship between Procedural Tactical Knowledge and Specific Motor Skills in Young Soccer Players

Directory of Open Access Journals (Sweden)

Rodrigo Aquino

2016-11-01

Full Text Available The purpose of this study was to investigate the association between offensive tactical knowledge and the soccer-specific motor skills performance. Fifteen participants were submitted to two evaluation tests, one to assess their technical and tactical analysis. The motor skills performance was measured through four tests of technical soccer skills: ball control, shooting, passing and dribbling. The tactical performance was based on a tactical assessment system called FUT-SAT (Analyses of Procedural Tactical Knowledge in Soccer. Afterwards, technical and tactical evaluation scores were ranked with and without the use of the cluster method. A positive, weak correlation was perceived in both analyses (rho = 0.39, not significant p = 0.14 (with cluster analysis; and rho = 0.35; not significant p = 0.20 (without cluster analysis. We can conclude that there was a weak association between the technical and the offensive tactical knowledge. This shows the need to reflect on the use of such tests to assess technical skills in team sports since they do not take into account the variability and unpredictability of game actions and disregard the inherent needs to assess such skill performance in the game.

Cooling of Electric Motors Used for Propulsion on SCEPTOR

Science.gov (United States)

Christie, Robert; Dubois, Authur; Derlaga, Joseph

2016-01-01

Benefits of Electric Power: Reduced energy consumption, Lower emissions, Less noise. Traction motors: Permanent magnet, Synchronous, High torque at low rotational speeds, High power density, (High concentration of heat). Annular inlet: Very compatible with PM motors, (Provides cooling where needed, No need for complicated ducting, Leads to a larger motor diameter which is beneficial for motor torque) Effect of prop wash on heat transfer coefficients: Assumed propeller induced turbulence would increase heat transfer coefficients, Holmes, Obara Yip reported 'propeller slipstream showed little if any apparent effect of the slip stream', Derlaga @ LaRC also found little change in heat transfer in the wake of the propeller.

Task-specific gross motor skills training for ambulant school-aged children with cerebral palsy: a systematic review.

Science.gov (United States)

Toovey, Rachel; Bernie, Charmaine; Harvey, Adrienne R; McGinley, Jennifer L; Spittle, Alicia J

2017-01-01

The primary objective is to systematically evaluate the evidence for the effectiveness of task-specific training (TST) of gross motor skills for improving activity and/or participation outcomes in ambulant school-aged children with cerebral palsy (CP). The secondary objective is to identify motor learning strategies reported within TST and assess relationship to outcome. Systematic review. Relevant databases were searched for studies including: children with CP (mean age >4 years and >60% of the sample ambulant); TST targeting gross motor skills and activity (skill performance, gross motor function and functional skills) and/or participation-related outcomes. Quality of included studies was assessed using standardised tools for risk of bias, study design and quality of evidence across outcomes. Continuous data were summarised for each study using standardised mean difference (SMD) and 95% CIs. Thirteen studies met inclusion criteria: eight randomised controlled trials (RCTs), three comparative studies, one repeated-measures study and one single-subject design study. Risk of bias was moderate across studies. Components of TST varied and were often poorly reported. Within-group effects of TST were positive across all outcomes of interest in 11 studies. In RCTs, between-group effects were conflicting for skill performance and functional skills, positive for participation-related outcomes (one study: Life-HABITS performance SMD=1.19, 95% CI 0.3 to 2.07, pmotor function. The quality of evidence was low-to-moderate overall. Variability and poor reporting of motor learning strategies limited assessment of relationship to outcome. Limited evidence for TST for gross motor skills in ambulant children with CP exists for improving activity and participation-related outcomes and recommendations for use over other interventions are limited by poor study methodology and heterogeneous interventions. PROSPERO ID42016036727.

Flood-proof motors

Energy Technology Data Exchange (ETDEWEB)

Schmitt, Marcus [AREVA NP GmbH, Erlangen (Germany)

2013-07-01

Even before the Fukushima event occurred some German nuclear power plants (NPP) have considered flooding scenarios. As a result of one of these studies, AREVA performed an upgrade project in NPP Isar 1 with flood-proof motors as a replacement of existing air-cooled low-voltage and high-voltage motors of the emergency cooling chain. After the Fukushima event, in which the cooling chains failed, the topic flood-proof equipment gets more and more into focus. This compact will introduce different kinds of flood-proof electrical motors which are currently installed or planned for installation into NPPs over the world. Moreover the process of qualification, as it was performed during the project in NPP Isar 1, will be shown. (orig.)

Flood-proof motors

International Nuclear Information System (INIS)

Schmitt, Marcus

2013-01-01

Even before the Fukushima event occurred some German nuclear power plants (NPP) have considered flooding scenarios. As a result of one of these studies, AREVA performed an upgrade project in NPP Isar 1 with flood-proof motors as a replacement of existing air-cooled low-voltage and high-voltage motors of the emergency cooling chain. After the Fukushima event, in which the cooling chains failed, the topic flood-proof equipment gets more and more into focus. This compact will introduce different kinds of flood-proof electrical motors which are currently installed or planned for installation into NPPs over the world. Moreover the process of qualification, as it was performed during the project in NPP Isar 1, will be shown. (orig.)

Task-specific effect of transcranial direct current stimulation on motor learning

Directory of Open Access Journals (Sweden)

Cinthia Maria Saucedo Marquez

2013-07-01

Full Text Available Transcranial direct current stimulation (tDCS is a relatively new non-invasive brain stimulation technique that modulates neural processes. When applied to the human primary motor cortex (M1, tDCS has beneficial effects on motor skill learning and consolidation in healthy controls and in patients. However, it remains unclear whether tDCS improves motor learning in a general manner or whether these effects depend on which motor task is acquired. Here we compare whether the effect of tDCS differs when the same individual acquires (1 a Sequential Finger Tapping Task (SEQTAP and (2 a Visual Isometric Pinch Force Task (FORCE. Both tasks have been shown to be sensitive to tDCS applied over M1, however, the underlying processes mediating learning and memory formation might benefit differently from anodal-tDCS. Thirty healthy subjects were randomly assigned to an anodal-tDCS group or sham-group. Using a double-blind, sham-controlled cross-over design, tDCS was applied over M1 while subjects acquired each of the motor tasks over 3 consecutive days, with the order being randomized across subjects. We found that anodal-tDCS affected each task differently: The SEQTAP task benefited from anodal-tDCS during learning, whereas the FORCE task showed improvements only at retention. These findings suggest that anodal tDCS applied over M1 appears to have a task-dependent effect on learning and memory formation.

Actions to promote energy efficient electric motors. Motors study group

Energy Technology Data Exchange (ETDEWEB)

Almeida, A.T. de [Coimbra Univ. (PT). Inst. of Systems and Robotics (ISR)

1996-10-01

Motor electricity consumption is influenced by many factors including: motor efficiency, motor speed controls, power supply quality, harmonics, systems oversizing, distribution network, mechanical transmission system, maintenance practices, load management and cycling, and the efficiency of the end-use device (e.g. fan, pump, etc.). Due to their importance, an overview of these factors is presented in this report. This study also describes the electricity use in the industrial and tertiary sectors and the electricity consumption associated with the different types of electric motors systems in the Member States of the European Union, as well as estimated future evolution until 2010. The studies for individual countries were carried out by the different partners of the motors study group at a previous stage. The study has found that there is a lack of accurate information about the motor electricity consumption, installed motor capacity and the motor market in almost all the European Union countries and only some general statistical sources are available. There is little field data, which is mainly available in Denmark, France, Italy and the Netherlands. Due to this lack of primary information, some common assumptions were made, based on the experience of the members of the study group. This lack of end-use characterisation data shows the need for improvement from the point of view of current knowledge. It is therefore recommended that further research is undertaken to arrive at more accurate figures. These could be the basis for a better understanding for motor use in practice and - as a consequence - for a more precise appraisal of potentials and barriers to energy efficiency. (orig.)

AC, DC or EC motor? What type of engine for what purpose?; AC-, DC- oder EC-Motor? Welche Motorausfuehrung fuer welchen Zweck

Energy Technology Data Exchange (ETDEWEB)

Zeiff, Andreas; Homburg, Dietrich

2009-01-15

Electronics is the key technology in control engineering, but even the best control system requires reliable modules to transmit signals. Modern electric motors have become indispensable here. There are nearly as many motor types as there are applications. Electromagnetic conversion of electric into mechanical power is directly related to motor design. There are AC and DC motors, one-speed motors and variable-speed motors. Rotary momentum and synchronisation can be optimized by selecting the appropriate motor type, as can dynamics and detent torque. Correct selection of the electric motor therefore is essential for an optimal drive concept. (orig.)

The prefrontal cortex shows context-specific changes in effective connectivity to motor or visual cortex during the selection of action or colour

DEFF Research Database (Denmark)

Rowe, James B.; Stephan, Klaas E.; Friston, Karl

2005-01-01

The role of the prefrontal cortex remains controversial. Neuroimaging studies support modality-specific and process-specific functions related to working memory and attention. Its role may also be defined by changes in its influence over other brain regions including sensory and motor cortex. We...... used functional magnetic imaging (fMRI) to study the free selection of actions and colours. Control conditions used externally specified actions and colours. The prefrontal cortex was activated during free selection, regardless of modality, in contrast to modality-specific activations outside...... included high-order interactions between modality, selection and regional activity. There was greater coupling between prefrontal cortex and motor cortex during free selection and action tasks, and between prefrontal cortex and visual cortex during free selection of colours. The results suggest...

Two-phase induction motor drives

DEFF Research Database (Denmark)

Blaabjerg, Frede; Lungeanu, Florin; Skaug, Kenneth

2004-01-01

There is a continuous debate today concerning the ?motor of the future? for low-power applications requiring less than 1-2 kW. The specialists are focusing on superior motors [1] like brushless-dc, permanent-magnet synchronous, or electronically commutated types, because they show improvements...... in efficiency, reliability, torque-per-volume/mass ratio, maintenance, and service life. Despite this effort, the industry seems to be responding with manifest rigidity in changing standard induction motor solutions when considering the installed volume into the field, the investment in manufacturing base...

Controlling An Inverter-Driven Three-Phase Motor

Science.gov (United States)

Dolland, C.

1984-01-01

Control system for three-phase permanent-magnet motor driven by linecommutated inverter uses signals generated by integrating back emf of each phase of motor. High-pass filter network eliminates low-frequency components from control loop while maintaining desired power factor.

Torque control for electric motors

Science.gov (United States)

Bernard, C. A.

1980-01-01

Method for adjusting electric-motor torque output to accomodate various loads utilizes phase-lock loop to control relay connected to starting circuit. As load is imposed, motor slows down, and phase lock is lost. Phase-lock signal triggers relay to power starting coil and generate additional torque. Once phase lock is recoverd, relay restores starting circuit to its normal operating mode.

Power electronics and motor drives

CERN Document Server

Wilamowski, Bogdan M

2011-01-01

Universities throughout the world typically provide an excellent education in the various aspects of electronics, however their focus is normally on traditional low power electronics. In contrast, in the industrial environment, there is a need for high power electronics that is used to control electromechanical systems in addition to the low power electronics typically employed for analog and digital systems. To address this need, Section 1 of this volume in The Industrial Electronics Handbook, Second Edition, is focused on special high power semiconductor devices. Section 2 not only describes

Commercializing a U.S. piezoceramic linear motor

Science.gov (United States)

Diehl, Rick W.

2000-06-01

A small low-cost piezoceramic linear motor has been developed in the US and is being commercialized by EDO Corporation, working with a leading motion control OEM and with a prominent US corporate research laboratory. First generation motor design has emphasized high displacement at up to 200mm per second velocity with 3.5 Newtons force with high resolution, short time constant and a 15 volt power supply at a cost of less than 100 dollars. Motor dimensions of 30 by 50 by 4 mm allow broad configuration choices, al hidden within the motion control slide. The EDO approach was to build on its core competence in high reliability electroceramic material engineering and production, and to use a strategy of back-integrating, or outsourcing of recent advances outside Edo in piezoceramics, while forward- integrating into specific emerging applications known intimately by the OEM in the market. The strategy provided design focus that has led to a cost-effective advance in 'solid-state actuation and control'. This is considered a classic case of successful industrial integration of an enabling technology across organizations in order to access the needed mix of technology for development of an innovative and competitive solution.

Keeping Order: Motor-Car Regulation and the Defeat of Victoria's 1905 Motor-Car Bill

Directory of Open Access Journals (Sweden)

Rick Clapton

2004-10-01

Full Text Available At the turn of the twentieth century some upper-class Victorians became motorists; consequently, for the first time ever, regulation and policing intersected with this class of society. By 1905 so many concerns had been raised about compromised public order and safety that the Victorian State Government attempted to implement a Motor Car Bill based on its English predecessor (1903. Wealthy motorists possessed power and influence, however, which contributed to the postponement of legislation until 1910. Additionally, parliamentarians were drawn from the same social class as motorists, and, in creating regulation, they were potentially regulating their peers, colleagues and friends. The private motor-car also brought with it new issues of civil liberty and responsibility. Finding a balance between the two continued to be a problem, as private transport gradually became affordable for middle- and working-class people, and both the number of regulations and the power of the motoring lobby increased.

Design principles and optimal performance for molecular motors under realistic constraints

Science.gov (United States)

Tu, Yuhai; Cao, Yuansheng

2018-02-01

The performance of a molecular motor, characterized by its power output and energy efficiency, is investigated in the motor design space spanned by the stepping rate function and the motor-track interaction potential. Analytic results and simulations show that a gating mechanism that restricts forward stepping in a narrow window in configuration space is needed for generating high power at physiologically relevant loads. By deriving general thermodynamics laws for nonequilibrium motors, we find that the maximum torque (force) at stall is less than its theoretical limit for any realistic motor-track interactions due to speed fluctuations. Our study reveals a tradeoff for the motor-track interaction: while a strong interaction generates a high power output for forward steps, it also leads to a higher probability of wasteful spontaneous back steps. Our analysis and simulations show that this tradeoff sets a fundamental limit to the maximum motor efficiency in the presence of spontaneous back steps, i.e., loose-coupling. Balancing this tradeoff leads to an optimal design of the motor-track interaction for achieving a maximum efficiency close to 1 for realistic motors that are not perfectly coupled with the energy source. Comparison with existing data and suggestions for future experiments are discussed.

Evaluation and prediction of the performance of positive displacement motor

Energy Technology Data Exchange (ETDEWEB)

Tudor, R.; Ginzburg, L. [Canadian Fracmaster Ltd., Calgary, AB (Canada); Xu, H. [Japan National Oil Corp (Japan); Li, J.; Robello, G.; Grigor, C.

1998-12-31

Test results of positive displacement motors (PDMs) collected by using various PDMs from a number of different suppliers have been analyzed. Various correlations have been developed and motor performance pumped with incompressible drilling fluid was evaluated based on test data provided by suppliers in the form of pressure drop versus torque output. Conclusions drawn from the study suggest that when a motor is operated at less than full load, the correlation between mechanical power and hydraulic power across the PDM power section can be described with a simple linear equation (different for each PDM type). Assuming the availability of patented geometric information for each PDM type, the performance of PDMs can be described by both the geometric parameters of the motor and the rheological properties of the circulation fluid. 9 refs., 8 figs.

Variable-Reluctance Motor For Electric Vehicles

Science.gov (United States)

Lang, Jeffrey H.

1987-01-01

Report describes research on variable-reluctance electric-motor drive for eventual use in electric-vehicle propulsion. Primary design and performance criteria were torque and power output per unit mass of motor, cost, and drive efficiency. For each criterion, optimized drive design developed, and designs unified to yield single electric-vehicle drive. Scaled-down motor performed as expected. Prototype of paraplegic lift operated by toggle switch and joystick. Lift plugs into household electrical outlet for recharging when not in use.

Design and measurements of the double layer planar motor

NARCIS (Netherlands)

Rovers, J.M.M.; Jansen, J.W.; Lomonova, E.

2013-01-01

Moving-magnet magnetically levitated planar motors are considered for use as a wafer stage in the semiconductor lithographic industry. This puts high requirements on the accuracy and the dissipated power and cooling performance of such motors. A novel planar motor topology is developed, which

Driver electronics design and control for a total artificial heart linear motor.

Science.gov (United States)

Unthan, Kristin; Cuenca-Navalon, Elena; Pelletier, Benedikt; Finocchiaro, Thomas; Steinseifer, Ulrich

2018-01-27

For any implantable device size and efficiency are critical properties. Thus, a linear motor for a Total Artificial Heart was optimized with focus on driver electronics and control strategies. Hardware requirements were defined from power supply and motor setup. Four full bridges were chosen for the power electronics. Shunt resistors were set up for current measurement. Unipolar and bipolar switching for power electronics control were compared regarding current ripple and power losses. Here, unipolar switching showed smaller current ripple and required less power to create the necessary motor forces. Based on calculations for minimal power losses Lorentz force was distributed to the actor's four coils. The distribution was determined as ratio of effective magnetic flux through each coil, which was captured by a force test rig. Static and dynamic measurements under physiological conditions analyzed interaction of control and hardware and all efficiencies were over 89%. In conclusion, the designed electronics, optimized control strategy and applied current distribution create the required motor force and perform optimal under physiological conditions. The developed driver electronics and control offer optimized size and efficiency for any implantable or portable device with multiple independent motor coils. Graphical Abstract ᅟ.

Nanoconfined catalytic Ångström-size motors

Energy Technology Data Exchange (ETDEWEB)

Colberg, Peter H., E-mail: pcolberg@chem.utoronto.ca; Kapral, Raymond, E-mail: rkapral@chem.utoronto.ca [Chemical Physics Theory Group, Department of Chemistry, University of Toronto, Toronto, Ontario M5S 3H6 (Canada)

2015-11-14

Self-propelled chemically powered synthetic micron and nano-scale motors are being intensively studied because of the wide range of potential applications that exploit their directed motion. This paper considers even smaller Ångström-size synthetic motors. Such very small motors in bulk solution display effects arising from their self-propulsion. Recent experiments have shown that small-molecule catalysts and single enzyme molecules exhibit properties that have been attributed to their chemical activity. Molecular dynamics is used to investigate the properties of very small Ångström-size synthetic chemically powered sphere-dimer motors in a simple atomic-like solvent confined between walls separated by distances of tens of nanometers. Evidence for strong structural ordering of the motors between the walls, which reflects the finite size of solvent molecules and depends on solvent depletion forces, is provided. Dynamical properties, such as average motor velocity, orientational relaxation, and mean square displacement, are anisotropic and depend on the distance from the walls. This research provides information needed for potential applications that use molecular-scale motors in the complex confined geometries encountered in biology and the laboratory.

Nanoconfined catalytic Ångström-size motors

International Nuclear Information System (INIS)

Colberg, Peter H.; Kapral, Raymond

2015-01-01

Self-propelled chemically powered synthetic micron and nano-scale motors are being intensively studied because of the wide range of potential applications that exploit their directed motion. This paper considers even smaller Ångström-size synthetic motors. Such very small motors in bulk solution display effects arising from their self-propulsion. Recent experiments have shown that small-molecule catalysts and single enzyme molecules exhibit properties that have been attributed to their chemical activity. Molecular dynamics is used to investigate the properties of very small Ångström-size synthetic chemically powered sphere-dimer motors in a simple atomic-like solvent confined between walls separated by distances of tens of nanometers. Evidence for strong structural ordering of the motors between the walls, which reflects the finite size of solvent molecules and depends on solvent depletion forces, is provided. Dynamical properties, such as average motor velocity, orientational relaxation, and mean square displacement, are anisotropic and depend on the distance from the walls. This research provides information needed for potential applications that use molecular-scale motors in the complex confined geometries encountered in biology and the laboratory

[Motor Skills of Extremely Obese Children and Adolescents Based on the Multicentre Longitudinal Obesity Database (APV)].

Science.gov (United States)

Koch, B; Graf, C; Hoffmeister, U; Platschek, A-M; Gruber, W; Holl, R

2016-03-01

Obese children and adolescents often exhibit progressively declining motor skills. To support young obese patients adequately, it is necessary to assess their individual physical and motor abilities, taking the degree of obesity into account. A total of 5 924 children and adolescents (mean age: 12.7±2.5 years, range 6.0-18.0 years, 3 195 girls) were examined in a standardised multicentre evaluation survey (APV). Fitness parameters were correlated with age- and gender-specific BMI-SDS (Standard Deviation Score) Methods: Anthropometric data were collected and patients performed the modified Munich fitness test (mMFT: maximal power, coordination, trunk flexibility) and a 6-min walk-test (aerobic endurance capacity). 33% of patients were extremely obese (BMI>99.5th percentile). Mean BMI-SDS was + 2.32±0.53 (♀-Δ=+ 0.06; pmotor performance, especially maximal power (r=- 0,134), and particularly aerobic endurance capacity (r=- 0,214; all pMotor performance was significantly below average (n=27 473, 6-18 years), especially among extremely obese patients. Performance in all motor tasks was lower in girls compared to boys, except for trunk flexibility (pmotor performance. Extremely obese patients and obese girls showed the most pronounced motor deficits. These results emphasize the importance of standardized evaluation of individual motor performance in children and adolescents with obesity. © Georg Thieme Verlag KG Stuttgart · New York.

Chemical and radiochemical specifications - PWR power plants; Specifications chimiques et radiochimiques - Centrales REP

Energy Technology Data Exchange (ETDEWEB)

Stutzmann, A [Electricite de France (EDF), 93 - Saint-Denis (France)

1997-07-01

Published by EDF this document gives the chemical specifications of the PWR (Pressurized Water Reactor) nuclear power plants. Among the chemical parameters, some have to be respected for the safety. These parameters are listed in the STE (Technical Specifications of Exploitation). The values to respect, the analysis frequencies and the time states of possible drops are noticed in this document with the motion STE under the concerned parameter. (A.L.B.)

FreedomCAR Advanced Traction Drive Motor Development Phase I

Energy Technology Data Exchange (ETDEWEB)

Ley, Josh (UQM Technologies, Inc.); Lutz, Jon (UQM Technologies, Inc.)

2006-09-01

The overall objective of this program is to design and develop an advanced traction motor that will meet the FreedomCAR and Vehicle Technologies (FCVT) 2010 goals and the traction motor technical targets. The motor specifications are given in Section 1.3. Other goals of the program include providing a cost study to ensure the motor can be developed within the cost targets needed for the automotive industry. The program has focused on using materials that are both high performance and low costs such that the performance can be met and cost targets are achieved. In addition, the motor technologies and machine design features must be compatible with high volume manufacturing and able to provide high reliability, efficiency, and ruggedness while simultaneously reducing weight and volume. Weight and volume reduction will become a major factor in reducing cost, material cost being the most significant part of manufacturing cost at high volume. Many motor technology categories have been considered in the past and present for traction drive applications, including: brushed direct current (DC), PM (PM) brushless dc (BLDC), alternating current (AC) induction, switched reluctance and synchronous reluctance machines. Of these machine technologies, PM BLDC has consistently demonstrated an advantage in terms of power density and efficiency. As rare earth magnet cost has declined, total cost may also be reduced over the other technologies. Of the many different configurations of PM BLDC machines, those which incorporate power production utilizing both magnetic torque as well as reluctance torque appear to have the most promise for traction applications. There are many different PM BLDC machine configurations which employ both of these torque producing mechanisms; however, most would fall into one of two categories--some use weaker magnets and rely more heavily on reluctance torque (reluctance-dominant PM machines), others use strong PMs and supplement with reluctance torque

Specificity of interactions among the DNA-packaging machine components of T4-related bacteriophages.

Science.gov (United States)

Gao, Song; Rao, Venigalla B

2011-02-04

Tailed bacteriophages use powerful molecular motors to package the viral genome into a preformed capsid. Packaging at a rate of up to ∼2000 bp/s and generating a power density twice that of an automobile engine, the phage T4 motor is the fastest and most powerful reported to date. Central to DNA packaging are dynamic interactions among the packaging components, capsid (gp23), portal (gp20), motor (gp17, large "terminase"), and regulator (gp16, small terminase), leading to precise orchestration of the packaging process, but the mechanisms are poorly understood. Here we analyzed the interactions between small and large terminases of T4-related phages. Our results show that the gp17 packaging ATPase is maximally stimulated by homologous, but not heterologous, gp16. Multiple interaction sites are identified in both gp16 and gp17. The specificity determinants in gp16 are clustered in the diverged N- and C-terminal domains (regions I-III). Swapping of diverged region(s), such as replacing C-terminal RB49 region III with that of T4, switched ATPase stimulation specificity. Two specificity regions, amino acids 37-52 and 290-315, are identified in or near the gp17-ATPase "transmission" subdomain II. gp16 binding at these sites might cause a conformational change positioning the ATPase-coupling residues into the catalytic pocket, triggering ATP hydrolysis. These results lead to a model in which multiple weak interactions between motor and regulator allow dynamic assembly and disassembly of various packaging complexes, depending on the functional state of the packaging machine. This might be a general mechanism for regulation of the phage packaging machine and other complex molecular machines.

Application of intelligent soft start in asynchronous motor

Science.gov (United States)

Du, Xue; Ye, Ying; Wang, Yuelong; Peng, Lei; Zhang, Suying

2018-05-01

The starting way of three phase asynchronous motor has full voltage start and step-down start. Direct starting brings large current impact, causing excessive local temperature to the power grid and larger starting torque will also impact the motor equipment and affect the service life of the motor. Aim at the problem of large current and torque caused by start-up, an intelligent soft starter is proposed. Through the application of intelligent soft start on asynchronous motor, highlights its application advantage in motor control.

Implementation of Motor Imagery during Specific Aerobic Training Session in Young Tennis Players.

Directory of Open Access Journals (Sweden)

Aymeric Guillot

Full Text Available The aim of this study was to investigate the effects of implementing motor imagery (MI during specific tennis high intensity intermittent training (HIIT sessions on groundstroke performance in young elite tennis players. Stroke accuracy and ball velocity of forehand and backhand drives were evaluated in ten young tennis players, immediately before and after having randomly performed two HIIT sessions. One session included MI exercises during the recovery phases, while the other included verbal encouragements for physical efforts and served as control condition. Results revealed that similar cardiac demand was observed during both sessions, while implementing MI maintained groundstroke accuracy. Embedding MI during HIIT enabled the development of physical fitness and the preservation of stroke performance. These findings bring new insight to tennis and conditioning coaches in order to fulfil the benefits of specific playing HIIT sessions, and therefore to optimise the training time.

Simulation and performance of brushless DC motor actuators

OpenAIRE

Gerba, Alex

1985-01-01

The simulation model for a Brushless D.C. Motor and the associated commutation power conditioner transistor model are presented. The necessary conditions for maximum power output while operating at steady-state speed and sinusoidally distributed air-gap flux are developed. Comparisons of simulated model with the measured performance of a typical motor are done both on time response waveforms and on average performance characteristics. These preliminary results indicate good ...

Modulation of motor performance and motor learning by transcranial direct current stimulation.

Science.gov (United States)

Reis, Janine; Fritsch, Brita

2011-12-01

Transcranial direct current stimulation (tDCS) has shown preliminary success in improving motor performance and motor learning in healthy individuals, and restitution of motor deficits in stroke patients. This brief review highlights some recent work. Within the past years, behavioural studies have confirmed and specified the timing and polarity specific effects of tDCS on motor skill learning and motor adaptation. There is strong evidence that timely co-application of (hand/arm) training and anodal tDCS to the contralateral M1 can improve motor learning. Improvements in motor function as measured by clinical scores have been described for combined tDCS and training in stroke patients. For this purpose, electrode montages have been modified with respect to interhemispheric imbalance after brain injury. Cathodal tDCS applied to the unlesioned M1 or bihemispheric M1 stimulation appears to be well tolerated and useful to induce improvements in motor function. Mechanistic studies in humans and animals are discussed with regard to physiological motor learning. tDCS is well tolerated, easy to use and capable of inducing lasting improvements in motor function. This method holds promise for the rehabilitation of motor disabilities, although acute studies in patients with brain injury are so far lacking.

Uncertainty analysis and design optimization of hybrid rocket motor powered vehicle for suborbital flight

Directory of Open Access Journals (Sweden)

Zhu Hao

2015-06-01

Full Text Available In this paper, we propose an uncertainty analysis and design optimization method and its applications on a hybrid rocket motor (HRM powered vehicle. The multidisciplinary design model of the rocket system is established and the design uncertainties are quantified. The sensitivity analysis of the uncertainties shows that the uncertainty generated from the error of fuel regression rate model has the most significant effect on the system performances. Then the differences between deterministic design optimization (DDO and uncertainty-based design optimization (UDO are discussed. Two newly formed uncertainty analysis methods, including the Kriging-based Monte Carlo simulation (KMCS and Kriging-based Taylor series approximation (KTSA, are carried out using a global approximation Kriging modeling method. Based on the system design model and the results of design uncertainty analysis, the design optimization of an HRM powered vehicle for suborbital flight is implemented using three design optimization methods: DDO, KMCS and KTSA. The comparisons indicate that the two UDO methods can enhance the design reliability and robustness. The researches and methods proposed in this paper can provide a better way for the general design of HRM powered vehicles.

The investigation of effects specific fuel comsumption and emissions fuel mixtures nitromethane

Directory of Open Access Journals (Sweden)

Samet Çelebi

2013-08-01

Full Text Available In this study, changes of specific fuel consumption and exhaust emmission values of chemical produced nitromethane are compared with values of gasoline fuel. In motor tests conducted at full load, gasoline mixture including % 5 nitromethane yield decreased specific fuel consumption value of 3200 min-1 and low engine speed of % 6,18 percentage. On the other hand, engine power is increased. While CO and HC emissions were observed to be less than gasoline, CO2 and NOx emissions remained to be increased. In performed tests, it is also observed that when mixing nitromethane with % 10 more gasoline, over knocking and unstable motor behavior is observed.

26 CFR 41.4482(a)-1 - Definition of highway motor vehicle.

Science.gov (United States)

2010-04-01

... of its own motor, whether such motor is powered by gasoline, diesel fuel, special motor fuels... 26 Internal Revenue 16 2010-04-01 2010-04-01 true Definition of highway motor vehicle. 41.4482(a... (CONTINUED) MISCELLANEOUS EXCISE TAXES EXCISE TAX ON USE OF CERTAIN HIGHWAY MOTOR VEHICLES Tax on Use of...

Evaluating the importance of social motor synchronization and motor skill for understanding autism.

Science.gov (United States)

Fitzpatrick, Paula; Romero, Veronica; Amaral, Joseph L; Duncan, Amie; Barnard, Holly; Richardson, Michael J; Schmidt, R C

2017-10-01

Impairments in social interaction and communicating with others are core features of autism spectrum disorder (ASD), but the specific processes underlying such social competence impairments are not well understood. An important key for increasing our understanding of ASD-specific social deficits may lie with the social motor synchronization that takes place when we implicitly coordinate our bodies with others. Here, we tested whether dynamical measures of synchronization differentiate children with ASD from controls and further explored the relationships between synchronization ability and motor control problems. We found (a) that children with ASD exhibited different and less stable patterns of social synchronization ability than controls; (b) children with ASD performed motor movements that were slower and more variable in both spacing and timing; and (c) some social synchronization that involved motor timing was related to motor ability but less rhythmic synchronization was not. These findings raise the possibility that objective dynamical measures of synchronization ability and motor skill could provide new insights into understanding the social deficits in ASD that could ultimately aid clinical diagnosis and prognosis. Autism Res 2017, 10: 1687-1699. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

Neuronal mechanisms of motor learning and motor memory consolidation in healthy old adults.

Science.gov (United States)

Berghuis, K M M; Veldman, M P; Solnik, S; Koch, G; Zijdewind, I; Hortobágyi, T

2015-06-01

It is controversial whether or not old adults are capable of learning new motor skills and consolidate the performance gains into motor memory in the offline period. The underlying neuronal mechanisms are equally unclear. We determined the magnitude of motor learning and motor memory consolidation in healthy old adults and examined if specific metrics of neuronal excitability measured by magnetic brain stimulation mediate the practice and retention effects. Eleven healthy old adults practiced a wrist extension-flexion visuomotor skill for 20 min (MP, 71.3 years), while a second group only watched the templates without movements (attentional control, AC, n = 11, 70.5 years). There was 40 % motor learning in MP but none in AC (interaction, p learn a new motor skill and consolidate the learned skill into motor memory, processes that are most likely mediated by disinhibitory mechanisms. These results are relevant for the increasing number of old adults who need to learn and relearn movements during motor rehabilitation.

Innovative Power Harvesting With Stepper Motor

OpenAIRE

N K Kaphungkui; Santanu Phukan; Sourav Mahanta; Sujata Mahanta; Anurag Kalita

2016-01-01

This paper present the innovative way of generating electricity using the principle of thermodynamics law. This law states that energy cannot be created nor destroyed but can be transform from one form to another. In this work, mechanical energy is converted into electricity using stepper motor which acts as a generator. Mechanical energy is freely generated and available such as in gym room and Children Park. The main aim of this work is the production of clean energy employing t...

MOV motor and gearbox performance under design basis loads

International Nuclear Information System (INIS)

DeWall, K.G.; Watkins, J.C.

1998-01-01

This paper describes the results of valve testing sponsored by the US Nuclear Regulatory Commission, Office of Nuclear Regulatory Research and conducted at the Idaho National Engineering and Environmental Laboratory. The research objective was to evaluate the capabilities of specific actuator motor and gearbox assemblies under various design basis loading conditions. The testing was performed using the motor-operated valve load simulator, a test fixture that simulates the stem load profiles a valve actuator would experience when closing a valve against flow and pressure loadings. The authors tested five typical motors (four ac motors and one dc motor) with three gearbox assemblies at conditions a motor might experience in a power plant, including such off-normal conditions as operation at high temperature and reduced voltage. The authors also determined the efficiency of the actuator gearbox. The testing produced the following significant results: all five motors operated at or above their rated torque during tests at full voltage and ambient temperature; for all five motors (dc as well as ac), the actual torque loss due to voltage degradation was greater than the torque loss predicted using common methods; startup torques in locked rotor tests compared well with stall torques in dynamometer-type tests; the methods commonly used to predict torque losses due to elevated operating temperatures sometimes bounded the actual losses, but not in all cases; the greatest discrepancy involved the prediction for the dc motor; running efficiencies published by the manufacturer for actuator gearboxes were higher than the actual efficiencies determined from testing, in some instances, the published pullout efficiencies were also higher than the actual values; operation of the gearbox at elevated temperature did not affect the operating efficiency

Radiological Effluent Technical Specifications (RETS) implementation, Kewaunee Nuclear Power Plant

International Nuclear Information System (INIS)

Serrano, W.; Akers, D.W.

1985-06-01

A review of the Radiological Effluent Technical Specifications (RETS) for the Kewaunee Nuclear Power Plant was performed. The principal review guidelines used were NUREG-0133, ''Preparation of Radiological Effluent Technical Specifications for Nuclear Power Plants,'' and Draft 7'' of NUREG-0472, Revision 3, ''Radiological Effluent Technical Specifications for Pressurized Water Reactors.'' Draft submittals were discussed with the Licensee by the NRC staff until all items requiring changes to the Technical Specifications were resolved. The Licensee then submitted final proposed RETS to the NRC which were evaluated and found to be in compliance with the NRC review guidelines. The proposed Offsite Dose Calculation Manual and the Radiological Environmental Monitoring Manual were reviewed and generally found to be in compliance with the NRC review guidelines

Ultrasonic Linear Motor with Two Independent Vibrations

Science.gov (United States)

Muneishi, Takeshi; Tomikawa, Yoshiro

2004-09-01

We propose a new structure of an ultrasonic linear motor in order to solve the problems of high-power ultrasonic linear motors that drive the XY-stage for electron beam equipment and to expand the application fields of the motor. We pay special attention to the following three points: (1) the vibration in two directions of the ultrasonic linear motor should not influence mutually each other, (2) the vibration in two directions should be divided into the stage traveling direction and the pressing direction of the ultrasonic linear motor, and (3) the rigidity of the stage traveling direction of the ultrasonic linear motor should be increased. As a result, the supporting method of ultrasonic linear motors is simplified. The efficiency of the motor is improved and temperature rise is reduced. The stage position drift is also improved.

Low Intensity Focused tDCS Over the Motor Cortex Shows Inefficacy to Improve Motor Imagery Performance

Directory of Open Access Journals (Sweden)

Irma N. Angulo-Sherman

2017-07-01

Full Text Available Transcranial direct current stimulation (tDCS is a brain stimulation technique that can enhance motor activity by stimulating the motor path. Thus, tDCS has the potential of improving the performance of brain-computer interfaces during motor neurorehabilitation. tDCS effects depend on several aspects, including the current density, which usually varies between 0.02 and 0.08 mA/cm2, and the location of the stimulation electrodes. Hence, testing tDCS montages at several current levels would allow the selection of current parameters for improving stimulation outcomes and the comparison of montages. In a previous study, we found that cortico-cerebellar tDCS shows potential of enhancing right-hand motor imagery. In this paper, we aim to evaluate the effects of the focal stimulation of the motor cortex over motor imagery. In particular, the effect of supplying tDCS with a 4 × 1 ring montage, which consists in placing an anode on the motor cortex and four cathodes around it, over motor imagery was assessed with different current densities. Electroencephalographic (EEG classification into rest or right-hand/feet motor imagery was evaluated on five healthy subjects for two stimulation schemes: applying tDCS for 10 min on the (1 right-hand or (2 feet motor cortex before EEG recording. Accuracy differences related to the tDCS intensity, as well as μ and β band power changes, were tested for each subject and tDCS modality. In addition, a simulation of the electric field induced by the montage was used to describe its effect on the brain. Results show no improvement trends on classification for the evaluated currents, which is in accordance with the observation of variable EEG band power results despite the focused stimulation. The lack of effects is probably related to the underestimation of the current intensity required to apply a particular current density for small electrodes and the relatively short inter-electrode distance. Hence, higher current

TFTR Motor Generator

International Nuclear Information System (INIS)

Murray, J.G.; Bronner, G.; Horton, M.

1977-01-01

A general description is given of 475 MVA pulsed motor generators for TFTR at Princeton Plasma Physics Laboratory. Two identical generators operating in parallel are capable of supplying 950 MVA for an equivalent square pulse of 6.77 seconds and 4,500 MJ at 0.7 power factor to provide the energy for the pulsed electrical coils and heating system for TFTR. The description includes the operational features of the 15,000 HP wound rotor motors driving each generator with its starting equipment and cycloconverter for controlling speed, power factor, and regulating line voltage during load pulsing where the generator speed changes from 87.5 to 60 Hz frequency variation to provide the 4,500 MJ or energy. The special design characteristics such as fatigue stress calculations for 10 6 cycles of operation, forcing factor on exciter to provide regulation, and low generator impedance are reviewed

Mechatronical Design Studies on Small Brushless Motors

Directory of Open Access Journals (Sweden)

W. Amrhein

2003-01-01

Full Text Available Brushless DC- and AC-permanent-magnet motors controlled by powerful micro-controller electronics have opened up a significant share of the small motor market in the last years. Based on the mechanical low cost construction of single-phase motor the paper presents electronic drive concepts to improve the performance and for special applications also the lifetime of brushless motors. The tangential and radial forces acting on the rotor are controlled by special phase current curves to reduce the torque ripple and to avoid expendable machinery parts like ball or sliding bearings.

Transcriptomics of aged Drosophila motor neurons reveals a matrix metalloproteinase that impairs motor function.

Science.gov (United States)

Azpurua, Jorge; Mahoney, Rebekah E; Eaton, Benjamin A

2018-04-01

The neuromuscular junction (NMJ) is responsible for transforming nervous system signals into motor behavior and locomotion. In the fruit fly Drosophila melanogaster, an age-dependent decline in motor function occurs, analogous to the decline experienced in mice, humans, and other mammals. The molecular and cellular underpinnings of this decline are still poorly understood. By specifically profiling the transcriptome of Drosophila motor neurons across age using custom microarrays, we found that the expression of the matrix metalloproteinase 1 (dMMP1) gene reproducibly increased in motor neurons in an age-dependent manner. Modulation of physiological aging also altered the rate of dMMP1 expression, validating dMMP1 expression as a bona fide aging biomarker for motor neurons. Temporally controlled overexpression of dMMP1 specifically in motor neurons was sufficient to induce deficits in climbing behavior and cause a decrease in neurotransmitter release at neuromuscular synapses. These deficits were reversible if the dMMP1 expression was shut off again immediately after the onset of motor dysfunction. Additionally, repression of dMMP1 enzymatic activity via overexpression of a tissue inhibitor of metalloproteinases delayed the onset of age-dependent motor dysfunction. MMPs are required for proper tissue architecture during development. Our results support the idea that matrix metalloproteinase 1 is acting as a downstream effector of antagonistic pleiotropy in motor neurons and is necessary for proper development, but deleterious when reactivated at an advanced age. © 2018 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

Task-specific recruitment of motor units for vibration damping.

Science.gov (United States)

Wakeling, James M; Liphardt, Anna-Maria

2006-01-01

Vibrations occur within the soft tissues of the lower extremities due to the heel-strike impact during walking. Increases in muscle activity in the lower extremities result in increased damping to reduce this vibration. The myoelectric intensity spectra were compared using principal component analysis from the tibialis anterior and lateral gastrocnemius of 40 subjects walking with different shoe conditions. The soft insert condition resulted in a significant, simultaneous increase in muscle activity with a shift to higher myoelectric frequencies in the period 0-60 ms after heel-strike which is the period when the greater vibration damping occurred. These increases in myoelectric frequency match the spectral patterns which indicate increases in recruitment of faster motor units. It is concluded that fast motor units are recruited during the task of damping the soft-tissue resonance that occurs following heel-strike.

The motor system and its disorders

DEFF Research Database (Denmark)

Rowe, James B; Siebner, Hartwig R

2012-01-01

to study safely the processes of neuroplasticity, neural networks and neuropharmacology in stroke and movement disorders and offers a sensitive tool to assess novel therapeutics. In the reverse direction, imaging of clinical populations has promoted innovations in cognitive theory, experimental design...... on the understanding of diverse motor functions, including motor learning, decision making, inhibition and the mirror neuron system. In addition, we show how imaging of the motor system has supported a powerful platform for bidirectional translational neuroscience. In one direction, it has provided the opportunity...

Principle and Basic Characteristics of Variable-Magnetic-Force Memory Motors

Science.gov (United States)

Sakai, Kazuto; Yuki, Kazuaki; Hashiba, Yutaka; Takahashi, Norio; Yasui, Kazuya; Kovudhikulrungsri, Lilit

A reduction in the power consumed by motors is required for energy saving in the case of electrical appliances and electric vehicles (EV). The motors used for operating these apparatus operate at variable speeds. Further, the motors operate with small load in stationary mode and with large load in start-up mode. A permanent magnet motor can operate at the rated power with a high efficiency. However, the efficiency is lower at small load or high speed because the large constant magnetic force results in substantial core loss. Furthermore, the flux-weakening current that depresses voltage at high speed leads to significant copper loss. Therefore, we have developed a new technique for controlling the magnetic force of permanent magnet on the basis of the load or speed of the motor. In this paper, we propose the novel motor that can vary magnetic flux and we clarify the principle.

Non-motor and motor features in LRRK2 transgenic mice.

Directory of Open Access Journals (Sweden)

Zoë Bichler

Full Text Available Non-motor symptoms are increasingly recognized as important features of Parkinson's disease (PD. LRRK2 mutations are common causes of familial and sporadic PD. Non-motor features have not been yet comprehensively evaluated in LRRK2 transgenic mouse models.Using a transgenic mouse model overexpressing the R1441G mutation of the human LRRK2 gene, we have investigated the longitudinal correlation between motor and non-motor symptoms and determined if specific non-motor phenotypes precede motor symptoms.We investigated the onset of motor and non-motor phenotypes on the LRRK2(R1441G BAC transgenic mice and their littermate controls from 4 to 21 month-old using a battery of behavioral tests. The transgenic mutant mice displayed mild hypokinesia in the open field from 16 months old, with gastrointestinal dysfunctions beginning at 6 months old. Non-motor features such as depression and anxiety-like behaviors, sensorial functions (pain sensitivity and olfaction, and learning and memory abilities in the passive avoidance test were similar in the transgenic animals compared to littermate controls.LRRK2(R1441G BAC transgenic mice displayed gastrointestinal dysfunction at an early stage but did not have abnormalities in fine behaviors, olfaction, pain sensitivity, mood disorders and learning and memory compared to non-transgenic littermate controls. The observations on olfaction and gastrointestinal dysfunction in this model validate findings in human carriers. These mice did recapitulate mild Parkinsonian motor features at late stages but compensatory mechanisms modulating the progression of PD in these models should be further evaluated.

Standing wave brass-PZT square tubular ultrasonic motor.

Science.gov (United States)

Park, Soonho; He, Siyuan

2012-09-01

This paper reports a standing wave brass-PZT tubular ultrasonic motor. The motor is composed of a brass square tube with two teeth on each tube end. Four PZT plates are attached to the outside walls of the brass tube. The motor requires only one driving signal to excite vibration in a single bending mode to generate reciprocating diagonal trajectories of teeth on the brass tube ends, which drive the motor to rotate. Bi-directional rotation is achieved by exciting different pairs of PZT plates to switch the bending vibration direction. Through using the brass-PZT tube structure, the motor can take high magnitude vibration to achieve a high output power in comparison to PZT tube based ultrasonic motors. Prototypes are fabricated and tested. The dimension of the brass-PZT tube is 3.975mm×3.975mm×16mm. Measured performance is a no-load speed of >1000RPM, a stall torque of 370μNm and a maximum output power of 16 mW when a sinusoidal driving voltage of 50V is applied. The working frequencies of the motor are 46,050Hz (clockwise) and 46,200Hz (counter-clockwise). Copyright © 2012. Published by Elsevier B.V.